Merge pull request #157 from CognitiveDisson/addUploadRetryDelay

Add a delay between network request retries
Fix config read
2022-07-15 18:38:20 +01:00 · 2022-07-15 18:01:22 +01:00 · 2022-07-14 18:06:35 +01:00 · 2022-07-14 17:44:31 +01:00 · 2022-07-14 17:38:48 +01:00 · 2022-07-14 17:37:46 +01:00
155 changed files with 5999 additions and 450 deletions
@@ -0,0 +1,65 @@
+---
+name: ⚠️ Bug Report
+about: Something isn't working as expected
+
+---
+
+<!--
+PLEASE HELP US PROCESS GITHUB ISSUES FASTER BY PROVIDING THE FOLLOWING INFORMATION.
+-->
+
+**My integration setup**
+
+[ ] CocoaPods cocoapods-xcremotecache plugin
+[ ] Automatic integration using `xcprepare integrate ...`
+[ ] Manual integration
+[ ] Carthage
+
+**Expected/desired behavior**
+<!-- Describe what the desired behavior would be. -->
+
+**Minimal reproduction of the problem with instructions**
+<!-- Please provide the *STEPS TO REPRODUCE*. -->
+
+**Producer Logs**
+<!-- Capture logs from 10 minutes: `log show --predicate 'sender BEGINSWITH "xc"' --style compact --info --debug -last 10m` -->
+
+<details>
+  <pre> [REPLACE THIS WITH YOUR INFORMATION] </pre>
+</details>
+
+**Consumer Logs**
+<!-- Capture logs from 10 minutes: `log show --predicate 'sender BEGINSWITH "xc"' --style compact --info --debug -last 10m` -->
+
+<details>
+  <pre> [REPLACE THIS WITH YOUR INFORMATION] </pre>
+</details>
+
+**Pods/Carthage file**
+<!-- Delete if you don't use CocoaPods or Carthage -->
+
+<details>
+  <pre> [REPLACE THIS WITH YOUR INFORMATION] </pre>
+</details>
+
+**Environment**
+
+* **XCRemoteCache:** X.Y.Z
+* **cocoapods-xcremotecache:** X.Y.Z <!-- check with `gem list cocoapods-xcremotecache` >
+* **HTTP cache server:** ... <!-- e.g. demo docker, nginx, AWS etc. >
+* **Xcode:** X.Y.Z
+
+**Post build stats**
+<!-- 
+To capture build statistics: 
+* call `xcprepare stats --reset` (or `XCRC/xcprepare stats --reset` for CocoaPods)
+* Build a project in Xcode
+* `xcprepare stats` (or `XCRC/xcprepare stats` for CocoaPods) 
+-->
+
+<details>
+  <pre> [REPLACE THIS WITH YOUR INFORMATION] </pre>
+</details>
+
+**Others**
+<!-- Anything else relevant?  Operating system version, , ... -->
@@ -0,0 +1,16 @@
+---
+name: 📕 Documentation Issue
+about: Suggestion for a change in a documentation
+
+---
+
+<!--
+PLEASE HELP US PROCESS GITHUB ISSUES FASTER BY PROVIDING THE FOLLOWING INFORMATION.
+-->
+
+**A suggestion**
+<!-- Describe how could the documentation be improved. -->
+
+**Which file, section, line**
+<!-- Provide a section it relates (if exist). -->
+
@@ -0,0 +1,20 @@
+---
+name: 🙏 Future Request
+about: Suggestion for an improvement, either behaviour or implementation
+
+---
+
+<!--
+PLEASE HELP US PROCESS GITHUB ISSUES FASTER BY PROVIDING THE FOLLOWING INFORMATION.
+-->
+
+
+**Expected/desired behavior**
+<!-- Describe what the desired behavior would be. -->
+
+**Relevant integration setup**
+
+[ ] CocoaPods cocoapods-xcremotecache plugin
+[ ] Automatic integration using `xcprepare integrate ...`
+[ ] Manual integration
+[ ] Carthage
@@ -9,11 +9,13 @@ jobs:
      - uses: actions/checkout@v1
      - name: SwiftLint
        uses: norio-nomura/action-swiftlint@3.1.0
+        with:
+          args: --strict

  macOS:
-    runs-on: macOS-latest
+    runs-on: macos-12
    env:
-      XCODE_VERSION: ${{ '12.4' }}
+      XCODE_VERSION: ${{ '13.3.1' }}
    steps:
      - name: Select Xcode
        run: "sudo xcode-select -s /Applications/Xcode_$XCODE_VERSION.app"
@@ -23,3 +25,5 @@ jobs:
        run: rake build[release]
      - name: Test
        run: rake test
+      - name: E2ETests
+        run: rake e2e_only
@@ -0,0 +1,24 @@
+name: Docs
+
+on:
+  push:
+    branches:
+      - master
+
+jobs:
+  docs:
+    runs-on: macos-12
+    env:
+      XCODE_VERSION: ${{ '13.3.1' }}
+    steps:
+      - uses: actions/checkout@v2
+      - name: Select Xcode
+        run: "sudo xcode-select -s /Applications/Xcode_$XCODE_VERSION.app"
+      - name: "Generate documentation"
+        run: "swift package --allow-writing-to-directory ./docs  generate-documentation --target XCRemoteCache --disable-indexing --transform-for-static-hosting --output-path ./docs  --hosting-base-path XCRemoteCache/"
+      - name: Deploy GH-pages
+        uses: peaceiris/actions-gh-pages@v3
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          publish_dir: ./docs
+          keep_files: false
@@ -6,9 +6,9 @@ on:
 jobs:
  macOS:
    name: Add macOS binaries to release
-    runs-on: macOS-latest
+    runs-on: macos-12
    env:
-      XCODE_VERSION: ${{ '12.4' }}
+      XCODE_VERSION: ${{ '13.3.1' }}
    steps:
      - name: Select Xcode
        run: "sudo xcode-select -s /Applications/Xcode_$XCODE_VERSION.app"
@@ -44,3 +44,29 @@ jobs:
          file_glob: true
          tag: ${{ github.ref }}
          overwrite: true
+  cocoapods:
+    name: Publish CocoaPods plugin
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    defaults:
+      run:
+        working-directory: cocoapods-plugin
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: '3.0'
+      - run: bundle install
+      - name: Publish to RubyGems
+        run: |
+          mkdir -p $HOME/.gem
+          touch $HOME/.gem/credentials
+          chmod 0600 $HOME/.gem/credentials
+          printf -- "---\n:rubygems_api_key: ${GEM_HOST_API_KEY}\n" > $HOME/.gem/credentials
+          gem build *.gemspec
+          CURRENT_VERSION=$(gem list cocoapods-xcremotecache  --remote  -q | sed 's/[^0-9\.]//g')
+          [ -f cocoapods-xcremotecache-$CURRENT_VERSION.gem ] && echo "Version $CURRENT_VERSION already exists" || gem push *.gem
+        env:
+          GEM_HOST_API_KEY: "${{secrets.RUBYGEMS_AUTH_TOKEN}}"
@@ -1,8 +1,13 @@
 .DS_Store
 /.build
 /Packages
-/*.xcodeproj
+*.xcodeproj/
+*.xcworkspace/
 DerivedData
 /.swiftpm/
 releases
-tmp/
+tmp/
+.idea/
+xcuserdata
+*.gem
+Pods/
@@ -63,6 +63,8 @@ excluded:
  - docs/
  - fastlane/
  - DerivedData/
+  - e2eTests/XCRemoteCacheSample/Pods
+  - e2eTests/StandaloneSampleApp

 attributes:
  always_on_same_line:
@@ -87,6 +89,25 @@ file_header:
                     \/\/  Created by .*? on .*\.
                     \/\/  Copyright © \d{4} .*\. All rights reserved\.
                     \/\/
+  required_pattern: |
+                     \/\/ Copyright \(c\) \d{4} Spotify AB\.
+                     \/\/
+                     \/\/ Licensed to the Apache Software Foundation \(ASF\) under one
+                     \/\/ or more contributor license agreements\.  See the NOTICE file
+                     \/\/ distributed with this work for additional information
+                     \/\/ regarding copyright ownership\.  The ASF licenses this file
+                     \/\/ to you under the Apache License, Version 2.0 \(the
+                     \/\/ "License"\); you may not use this file except in compliance
+                     \/\/ with the License\.  You may obtain a copy of the License at
+                     \/\/
+                     \/\/ http:\/\/www.apache.org\/licenses\/LICENSE-2\.0
+                     \/\/
+                     \/\/ Unless required by applicable law or agreed to in writing,
+                     \/\/ software distributed under the License is distributed on an
+                     \/\/ \"AS IS\" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+                     \/\/ KIND, either express or implied\.  See the License for the
+                     \/\/ specific language governing permissions and limitations
+                     \/\/ under the License\.
 force_cast: warning
 force_try: warning
 implicit_getter: warning
@@ -123,6 +144,6 @@ custom_rules:
    severity: warning
  trailing_dot_in_comments:
    name: "Trailing dot in comments"
-    regex: '^[ ]*///?[^\n]*\.\n'
+    regex: '^(?!\/\/\ Copyright\ \(c\)\ \d{4}\ Spotify AB\.|\/\/\ under\ the\ License\.)[ ]*///?[^\n]*\.\n'
    message: "There shouldn't be trailing dot in comments"
    severity: warning
@@ -3,16 +3,16 @@
    "pins": [
      {
        "package": "AEXML",
-        "repositoryURL": "https://github.com/tadija/AEXML",
+        "repositoryURL": "https://github.com/tadija/AEXML.git",
        "state": {
          "branch": null,
-          "revision": "8623e73b193386909566a9ca20203e33a09af142",
-          "version": "4.5.0"
+          "revision": "38f7d00b23ecd891e1ee656fa6aeebd6ba04ecc3",
+          "version": "4.6.1"
        }
      },
      {
        "package": "PathKit",
-        "repositoryURL": "https://github.com/kylef/PathKit",
+        "repositoryURL": "https://github.com/kylef/PathKit.git",
        "state": {
          "branch": null,
          "revision": "73f8e9dca9b7a3078cb79128217dc8f2e585a511",
@@ -37,13 +37,22 @@
          "version": "0.0.5"
        }
      },
+      {
+        "package": "SwiftDocCPlugin",
+        "repositoryURL": "https://github.com/apple/swift-docc-plugin",
+        "state": {
+          "branch": null,
+          "revision": "3303b164430d9a7055ba484c8ead67a52f7b74f6",
+          "version": "1.0.0"
+        }
+      },
      {
        "package": "XcodeProj",
        "repositoryURL": "https://github.com/tuist/XcodeProj.git",
        "state": {
          "branch": null,
-          "revision": "0b18c3e7a10c241323397a80cb445051f4494971",
-          "version": "8.0.0"
+          "revision": "c75c3acc25460195cfd203a04dde165395bf00e0",
+          "version": "8.7.1"
        }
      },
      {
@@ -51,8 +60,8 @@
        "repositoryURL": "https://github.com/jpsim/Yams.git",
        "state": {
          "branch": null,
-          "revision": "53741ba55ecca5c7149d8c9f810913ec80845c69",
-          "version": "3.0.0"
+          "revision": "00c403debcd0a007b854bb35e598466207a2d58c",
+          "version": "5.0.0"
        }
      },
      {
@@ -60,8 +69,8 @@
        "repositoryURL": "https://github.com/marmelroy/Zip.git",
        "state": {
          "branch": null,
-          "revision": "80b1c3005ee25b4c7ce46c4029ac3347e8d5e37e",
-          "version": "2.0.0"
+          "revision": "67fa55813b9e7b3b9acee9c0ae501def28746d76",
+          "version": "2.1.2"
        }
      }
    ]
@@ -1,4 +1,5 @@
-// swift-tools-version:5.1
+// swift-tools-version:5.3
+// swiftlint:disable:previous file_header
 // The swift-tools-version declares the minimum version of Swift required to build this package

 import PackageDescription
@@ -12,10 +13,11 @@ let package = Package(
        .executable(name: "xcprebuild", targets: ["xcprebuild"]),
    ],
    dependencies: [
-        .package(url: "https://github.com/marmelroy/Zip.git", from: "2.0.0"),
-        .package(url: "https://github.com/jpsim/Yams.git", from: "3.0.0"),
+        .package(url: "https://github.com/marmelroy/Zip.git", from: "2.1.2"),
+        .package(url: "https://github.com/jpsim/Yams.git", from: "5.0.0"),
        .package(url: "https://github.com/apple/swift-argument-parser", from: "0.0.1"),
-        .package(url: "https://github.com/tuist/XcodeProj.git", from: "8.0.0"),
+        .package(url: "https://github.com/tuist/XcodeProj.git", from: "8.7.1"),
+        .package(url: "https://github.com/apple/swift-docc-plugin", from: "1.0.0"),
    ],
    targets: [
        .target(
@@ -49,14 +51,19 @@ let package = Package(
            name: "xcld",
            dependencies: ["XCRemoteCache"]
        ),
+        .target(
+            name: "xcldplusplus",
+            dependencies: ["XCRemoteCache"]
+        ),
        .target(
            // Wrapper target that builds all binaries but does nothing in runtime
            name: "Aggregator",
-            dependencies: ["xcprebuild", "xcswiftc", "xclibtool", "xcpostbuild", "xcprepare", "xcld"]
+            dependencies: ["xcprebuild", "xcswiftc", "xclibtool", "xcpostbuild", "xcprepare", "xcld", "xcldplusplus"]
        ),
        .testTarget(
            name: "XCRemoteCacheTests",
-            dependencies: ["XCRemoteCache"]
+            dependencies: ["XCRemoteCache"],
+            resources: [.copy("TestData")]
        ),
    ]
 )
@@ -1,13 +1,16 @@
 <p align="center">
-    <img src="docs/img/logo.png" width="75%">
+    <img src="docs/img/logo.png#gh-light-mode-only" width="75%">
+    <img src="docs/img/logo-dark.png#gh-dark-mode-only" width="75%">
 </p>

 _XCRemoteCache is a remote cache tool for Xcode projects. It reuses target artifacts generated on a remote machine, served from a simple REST server._

 [![Build Status](https://github.com/spotify/XCRemoteCache/workflows/CI/badge.svg)](https://github.com/spotify/XCRemoteCache/workflows/CI/badge.svg)
 [![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](LICENSE)
+[![Slack](https://slackin.spotify.com/badge.svg)](https://slackin.spotify.com)
+[![Docs](https://spotify.github.io/XCRemoteCache/documentation/xcremotecache/)](https://github.com/spotify/XCRemoteCache/workflows/Docs/badge.svg)

- [How and Why?](#how-and-why-)
+- [How and Why?](#how-and-why)
  * [Accurate target input files](#accurate-target-input-files)
    + [New file added to the target](#new-file-added-to-the-target)
  * [Debug symbols](#debug-symbols)
@@ -36,10 +39,14 @@ _XCRemoteCache is a remote cache tool for Xcode projects. It reuses target artif
  * [Amazon S3 and Google Cloud Storage](#amazon-s3-and-google-cloud-storage)
 - [CocoaPods plugin](#cocoapods-plugin)
 - [Requirements](#requirements)
+- [Apple silicon support](#apple-silicon-support)
+  * [Artifacts per architecture (Recommended)](#artifacts-per-architecture-recommended)
+  * [Fat artifacts](#fat-artifacts)
 - [Limitations](#limitations)
 - [FAQ](#faq)
 - [Development](#development)
 - [Release](#release)
+  * [Releasing CocoaPods plugin](#releasing-cocoapods-plugin)
  * [Building release package](#building-release-package)
 - [Contributing](#contributing)
 - [Code of conduct](#code-of-conduct)
@@ -50,7 +57,7 @@ _XCRemoteCache is a remote cache tool for Xcode projects. It reuses target artif

 The caching mechanism is based on remote artifacts that should be generated and uploaded to the cache server for each commit on a `master` branch, preferably as a part of CI/CD step. Xcode products are not portable between different Xcode versions, each XCRemoteCache artifact is linked with a specific Xcode build number that generated it. To support multiple Xcode versions, artifacts generation should happen for each Xcode version.

-The artifact resue flow is as follows: XCRemoteCache performs a target precheck (aka prebuild) and if a fingerprint for local sources matches the one computed on a generation side, several compilation steps wrappers (e.g. `xcswiftc`, `xccc`, `xclibtool`) mock corresponding compilation step(s) and linking (or archiving) moves the cached build artifact to the expected location.
+The artifact reuse flow is as follows: XCRemoteCache performs a target precheck (aka prebuild) and if a fingerprint for local sources matches the one computed on a generation side, several compilation steps wrappers (e.g. `xcswiftc`, `xccc`, `xclibtool`) mock corresponding compilation step(s) and linking (or archiving) moves the cached build artifact to the expected location.

 > Multiple commits that have the same target sources reuse artifact package on a remote server.

@@ -134,7 +141,7 @@ xcremotecache/xcprepare integrate --input <yourProject.xcodeproj> --mode consume
 | Argument | Description | Default | Required |
 | ------------- | ------------- | ------------- | ------------- |
 | `--input` | .xcodeproj location  | N/A | ✅ |
-| `--mode` | mode. Supported values: `consumer`, `producer` | N/A | ✅ |
+| `--mode` | mode. Supported values: `consumer`, `producer`, `producer-fast`(experimental) | N/A | ✅ |
 | `--targets-include` | comma-separated list of targets to integrate XCRemoteCache. | `""` | ⬜️ |
 | `--targets-exclude` | comma-separated list of targets to not integrate XCRemoteCache. Takes priority over --targets-include.  | `""` | ⬜️ |
 | `--configurations-include` | comma-separated list of configurations to integrate XCRemoteCache.  | `""` | ⬜️ |
@@ -189,6 +196,9 @@ Configure Xcode targets that **should use** XCRemoteCache:
 * `SWIFT_EXEC` - location of `xcprepare` (e.g. `xcremotecache/xcswiftc`)
 * `LIBTOOL` - location of `xclibtool` (e.g. `xcremotecache/xclibtool`)
 * `LD` - location of `xcld` (e.g. `xcremotecache/xcld`)
+* `LDPLUSPLUS` - location of `xcldplusplus` (e.g. `xcremotecache/xcldplusplus`)
+* `XCRC_PLATFORM_PREFERRED_ARCH` - `$(LINK_FILE_LIST_$(CURRENT_VARIANT)_$(PLATFORM_PREFERRED_ARCH):dir:standardizepath:file:default=arm64)`
+* `SWIFT_USE_INTEGRATED_DRIVER` - `NO` (required in Xcode 14.0+)

 <details>
  <summary>Screenshot</summary>
@@ -208,8 +218,8 @@ Configure Xcode targets that **should use** XCRemoteCache:
 * command: `"$SCRIPT_INPUT_FILE_0"`
 * input files: location of `xcpostbuild` command (e.g. `xcremotecache/xcpostbuild`)
 * output files: 
-  * `$(TARGET_BUILD_DIR)/$(MODULES_FOLDER_PATH)/$(PRODUCT_MODULE_NAME).swiftmodule/$(PLATFORM_PREFERRED_ARCH).swiftmodule.md5`
-  * `$(TARGET_BUILD_DIR)/$(MODULES_FOLDER_PATH)/$(PRODUCT_MODULE_NAME).swiftmodule/$(PLATFORM_PREFERRED_ARCH)-$(LLVM_TARGET_TRIPLE_VENDOR)-$(SWIFT_PLATFORM_TARGET_PREFIX)$(LLVM_TARGET_TRIPLE_SUFFIX).swiftmodule.md5`
+  * `$(TARGET_BUILD_DIR)/$(MODULES_FOLDER_PATH)/$(PRODUCT_MODULE_NAME).swiftmodule/$(XCRC_PLATFORM_PREFERRED_ARCH).swiftmodule.md5`
+  * `$(TARGET_BUILD_DIR)/$(MODULES_FOLDER_PATH)/$(PRODUCT_MODULE_NAME).swiftmodule/$(XCRC_PLATFORM_PREFERRED_ARCH)-$(LLVM_TARGET_TRIPLE_VENDOR)-$(SWIFT_PLATFORM_TARGET_PREFIX)$(LLVM_TARGET_TRIPLE_SUFFIX).swiftmodule.md5`
 * discovery dependency file: `$(TARGET_TEMP_DIR)/postbuild.d`

 <details>
@@ -257,7 +267,7 @@ $ xcremotecache/xcprepare mark --configuration Debug --platform iphonesimulator

 That command creates an empty file on a remote server which informs that for given sha, configuration, platform, Xcode versions etc. all artifacts are available.

-_Note that for the `producer` mode, the prebuild build phase and `xccc`, `xcld`, `xclibtool` wrappers become no-op, so it is recommended to not add them for the `producer` mode._
+_Note that for the `producer` mode, the prebuild build phase and `xccc`, `xcld`, `xcldplusplus`, `xclibtool` wrappers become no-op, so it is recommended to not add them for the `producer` mode._

 ## A full list of configuration parameters:

@@ -281,13 +291,14 @@ _Note that for the `producer` mode, the prebuild build phase and `xccc`, `xcld`,
 | `cache_commit_history` | Number of historical git commits to look for cache artifacts | `10` | ⬜️ |
 | `source_root` | Source root of the Xcode project | `""` | ⬜️ |
 | `fingerprint_override_extension` | Fingerprint override extension (sample override `Module.swiftmodule/x86_64.swiftmodule.md5`) | `md5` | ⬜️ |
-| `extra_configuration_file` | Configuration file that overrides project configuration | `user.rcinfo` | ⬜️ |
+| `extra_configuration_file` | Configuration file that overrides project configuration (this property can be overriden multiple times in different files to chain extra configuration files) | `user.rcinfo` | ⬜️ |
 | `publishing_sha` | Custom commit sha to publish artifact (producer only) | `nil` | ⬜️ |
 | `artifact_maximum_age` | Maximum age in days HTTP response should be locally cached before being evicted | `30` | ⬜️ |
 | `custom_fingerprint_envs` | Extra ENV keys that should be convoluted into the environment fingerprint | `[]` | ⬜️ |
 | `stats_dir` | Directory where all XCRemoteCache statistics (e.g. counters) are stored | `~/.xccache` | ⬜️ |
 | `download_retries` | Number of retries for download requests | `0` | ⬜️ |
 | `upload_retries` | Number of retries for upload requests | `3` | ⬜️ |
+| `retry_delay` | Delay between retries in seconds | `10` | ⬜️ |
 | `request_custom_headers` | Dictionary of extra HTTP headers for all remote server requests | `[]` | ⬜️ |
 | `thin_target_mock_filename` | Filename (without an extension) of the compilation input file that is used as a fake compilation for the forced-cached target (aka thin target) | `standin` | ⬜️ |
 | `focused_targets` | A list of all targets that are not thinned. If empty, all targets are meant to be non-thin | `[]` | ⬜️ |
@@ -298,11 +309,17 @@ _Note that for the `producer` mode, the prebuild build phase and `xccc`, `xcld`,
 | `product_files_extensions_with_content_override ` | List of all extensions that should carry over source fingerprints. Extensions of all product files that contain non-deterministic content (absolute paths, timestamp, etc) should be included. | `["swiftmodule"]` | ⬜️ |
 | `thinning_enabled ` | If true, support for thin projects is enabled | `false` | ⬜️ |
 | `thinning_target_module_name ` | Module name of a target that works as a helper for thinned targets | `"ThinningRemoteCacheModule"` | ⬜️ |
+| `prettify_meta_files` | A Boolean value that opts-in pretty JSON formatting for meta files | `false` | ⬜️ |
 | `aws_secret_key` | Secret key for AWS V4 Signature Authorization. If this is set to a non-empty String - an Authentication Header will be added based on this and the other `aws_*` parameters.| `""` | ⬜️ |
 | `aws_access_key` | Access key for AWS V4 Signature Authorization. | `""` | ⬜️ |
+| `aws_security_token` | Temporary security token provided by the AWS Security Token Service. | `nil` | ⬜️ |
 | `aws_region` | Region for AWS V4 Signature Authorization. E.g. `eu`.  | `""` | ⬜️ |
 | `aws_service` | Service for AWS V4 Signature Authorization. E.g. `storage`. | `""` | ⬜️ |
-
+| `out_of_band_mappings` | A dictionary of files path remapping that should be applied to make it absolute path agnostic on a list of dependencies. Useful if a project refers files out of repo root, either compilation files or precompiled dependencies. Keys represent generic replacement and values are substrings that should be replaced. Example: for mapping `["COOL_LIBRARY": "/CoolLibrary"]` `/CoolLibrary/main.swift`will be represented as `$(COOL_LIBRARY)/main.swift`). Warning: remapping order is not-deterministic so avoid remappings with multiple matchings. | `[:]` | ⬜️ |
+| `disable_certificate_verification` | A Boolean value that opts-in SSL certificate validation is disabled | `false` | ⬜️ |
+| `disable_vfs_overlay` | A feature flag to disable virtual file system overlay support (temporary) | `false` | ⬜️ |
+| `custom_rewrite_envs` | A list of extra ENVs that should be used as placeholders in the dependency list. ENV rewrite process is optimistic - does nothing if an ENV is not defined in the pre/postbuild process. | `[]` | ⬜️ |
+| `irrelevant_dependencies_paths` | Regexes of files that should not be included in a list of dependencies. Warning! Add entries here with caution - excluding dependencies that are relevant might lead to a target overcaching. The regex can match either partially or fully the filepath, e.g. `\\.modulemap$` will exclude all `.modulemap` files. | `[]` | ⬜️ |

 ## Backend cache server

@@ -340,6 +357,8 @@ XCRemoteCache supports Amazon S3 and Google Cloud Storage buckets to be used as

 To set it up use the configuration parameters `aws_secret_key`, `aws_access_key`, `aws_region`, and `aws_service` in the `.rcinfo` file. Specify the URL to the bucket in cache-addresses field in the same file.

+XCRemoteCache also supports [AWS Temporary Access Keys](https://docs.aws.amazon.com/general/latest/gr/aws-sec-cred-types.html#temporary-access-keys). Use additional `aws_security_token` parameter combined with `aws_secret_key`, `aws_access_key` to set it up. [This page](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/configuring-instance-metadata-service.html) describes how to receive a security token. 
+
 Example
 ```yaml
 ...
@@ -358,6 +377,31 @@ Retention Policy: Buckets usually have a retention policy option which ensures o

 Head over to our [cocoapods-plugin](cocoapods-plugin/README.md) docs to see how to integrate XCRemoteCache in your CocoaPods project.

+## Apple silicon support
+
+### Artifacts per architecture (Recommended)
+
+_If all of your machines (both producer and all consumers have the same architecture, either Intel or Apple Silicon), you don't have to do anything._
+
+XCRemoteCache supports building artifacts for Apple silicon consumers. Is it recommended to build separately for `x86_64` and `arm64` architectures to have single-architecture artifacts that do not require downloading irrelevant binaries. Here are required steps if you want to support both Intel and Apple silicon consumers.
+
+* Building for a simulator on a producer: run a first build for `x86_64`, clean a build and build again for `arm64`, e.g.:
+```
+xcodebuild ARCHS=x86_64 ONLY_ACTIVE_ARCH=NO build ...
+xcodebuild clean
+xcodebuild ARCHS=arm64 ONLY_ACTIVE_ARCH=NO build ...
+```
+
+### Fat artifacts
+
+If you prefer to generate far artifacts (with both Intel and Apple silicon binaries), you can disable "Build Archive Architecture Only" on a producer side, e.g.
+
+```
+xcodebuild ONLY_ACTIVE_ARCH=NO build ...
+```
+
+Note: This setup is not recommended and may not be supported in future XCRemoteCache releases.
+
 ## Requirements

 * The repo under `git` version control
@@ -368,12 +412,14 @@ Head over to our [cocoapods-plugin](cocoapods-plugin/README.md) docs to see how
 * Recommended: multi-targets Xcode project
 * Recommended: do not use fast-forward PR strategy (use merge or squash instead)
 * Recommended: avoid `DWARF with dSYM File` "Debug Information Format" build setting. Use `DWARF` instead
+* Recommended: avoid having a symbolic link in the source root (e.g. placing a project in `/tmp`) 

 ## Limitations

-* Swift Package Manager (SPM) projects are not supported
+* Swift Package Manager (SPM) dependencies are not supported. _Because SPM does not allow customizing Build Settings, XCRemoteCache cannot specify `clang` and `swiftc` wrappers that control if the local compilation should be skipped (cache hit) or not (cache miss)_
 * Filenames with `_vers.c` suffix are reserved and cannot be used as a source file
 * All compilation files should be referenced via the git repo root. Referencing `/AbsolutePath/someOther.swift` or `../../someOther.swift` that resolve to the location outside of the git repo root is prohibited.
+* The new Swift driver (introduced by default in Xcode 14.0) is not supported and has to be disabled when using XCRemoteCache

 ## FAQ

@@ -388,6 +434,12 @@ Follow the [Development](docs/Development.md) guide. It has all the information
 To release a version, in [Releases](https://github.com/spotify/XCRemoteCache/releases) draft a new release with `v0.3.0{-rc0}` tag format. 
 Packages with binaries will be automatically uploaded to the GitHub [Releases](https://github.com/spotify/XCRemoteCache/releases) page.

+### Releasing CocoaPods plugin
+
+Bump a gem version defined in [gem_version.rb](cocoapods-plugin/lib/cocoapods-xcremotecache/gem_version.rb) and create a new release described above.
+
+A plugin is automatically uploaded to [RubyGems](https://rubygems.org/gems/cocoapods-xcremotecache) if a given version doesn't exist yet.
+
 ### Building release package

 To build a release zip package for a single platform (e.g. `x86_64-apple-macosx`, `arm64-apple-macosx`), call:
@@ -398,6 +450,12 @@ rake 'build[release, x86_64-apple-macosx]'

 The zip package will be generated at `releases/XCRemoteCache.zip`.

+## Support
+
+Create a [new issue](https://github.com/spotify/XCRemoteCache/issues/new) with as many details as possible.
+
+Reach us at the `#xcremotecache` channel in [Slack](https://slackin.spotify.com/).
+
 ## Contributing

 We feel that a welcoming community is important and we ask that you follow Spotify's 
@@ -1,4 +1,5 @@
 # encoding: utf-8
+require_relative 'tasks/e2e'

 ################################
 # Rake configuration
@@ -9,7 +10,7 @@ DERIVED_DATA_DIR = File.join('.build').freeze
 RELEASES_ROOT_DIR = File.join('releases').freeze

 EXECUTABLE_NAME = 'XCRemoteCache'
-EXECUTABLE_NAMES = ['xclibtool', 'xcpostbuild', 'xcprebuild', 'xcprepare', 'xcswiftc', 'xcld'] 
+EXECUTABLE_NAMES = ['xclibtool', 'xcpostbuild', 'xcprebuild', 'xcprepare', 'xcswiftc', 'xcld', 'xcldplusplus'] 
 PROJECT_NAME = 'XCRemoteCache'

 SWIFTLINT_ENABLED = true
@@ -28,7 +29,7 @@ task :lint => [:prepare] do
  puts 'Run linting'

  system("swiftformat --lint --config .swiftformat --cache ignore .") or abort "swiftformat failure" if SWIFTFORMAT_ENABLED
-  system("swiftlint lint --config .swiftlint.yml") or abort "swiftlint failure" if SWIFTLINT_ENABLED
+  system("swiftlint lint --config .swiftlint.yml --strict") or abort "swiftlint failure" if SWIFTLINT_ENABLED
 end

 task :autocorrect => [:prepare]  do 
@@ -77,6 +78,12 @@ task :test do
  spm_test()
 end

+desc 'build and run E2E tests'
+task :e2e => [:build, :e2e_only]
+
+desc 'run E2E tests without building the XCRemoteCache binary'
+task :e2e_only => ['e2e:run']
+
 ################################
 # Helper functions
 ################################
@@ -41,6 +41,7 @@ class BuildArtifactCreator: ArtifactSwiftProductsBuilderImpl, ArtifactCreator {
    private let moduleName: String?
    private let modulesFolderPath: String
    private let dSYMPath: URL
+    private let metaWriter: MetaWriter
    private let fileManager: FileManager

    init(
@@ -50,6 +51,7 @@ class BuildArtifactCreator: ArtifactSwiftProductsBuilderImpl, ArtifactCreator {
        moduleName: String?,
        modulesFolderPath: String,
        dSYMPath: URL,
+        metaWriter: MetaWriter,
        fileManager: FileManager
    ) {
        self.buildDir = buildDir
@@ -59,6 +61,7 @@ class BuildArtifactCreator: ArtifactSwiftProductsBuilderImpl, ArtifactCreator {
        self.moduleName = moduleName
        self.fileManager = fileManager
        self.dSYMPath = dSYMPath
+        self.metaWriter = metaWriter
        super.init(workingDir: tempDir, moduleName: moduleName, fileManager: fileManager)
    }

@@ -72,7 +75,11 @@ class BuildArtifactCreator: ArtifactSwiftProductsBuilderImpl, ArtifactCreator {
        let dynamicLibraryArtifacts = try prepareDynamicLibraryArtifacts()
        zipPaths.append(contentsOf: dynamicLibraryArtifacts)

-        let creator = ZipArtifactCreator(workingDir: zipWorkingDir, fileManager: fileManager)
+        let creator = ZipArtifactCreator(
+            workingDir: zipWorkingDir,
+            metaWriter: metaWriter,
+            fileManager: fileManager
+        )
        return try creator.createArtifact(zipContent: zipPaths, artifactKey: artifactKey, meta: meta)
    }

@@ -51,8 +51,6 @@ protocol ArtifactSwiftProductsBuilder {
 /// # {workingDir}/xccache/produced/include/#{moduleName} (if `moduleName` is defined)
 class ArtifactSwiftProductsBuilderImpl: ArtifactSwiftProductsBuilder {

-    /// List of all required swiftmodule related extensions that should be copied to the artifact
-    private static let swiftmoduleExtensionsToInclude = ["swiftmodule", "swiftdoc", "swiftsourceinfo"]
    private let workingDir: URL
    private let moduleName: String?
    private let fileManager: FileManager
@@ -30,6 +30,7 @@ enum SwiftmoduleFileExtension: String {
    case swiftmodule
    case swiftdoc
    case swiftsourceinfo
+    case swiftinterface
 }

 extension SwiftmoduleFileExtension {
@@ -38,5 +39,6 @@ extension SwiftmoduleFileExtension {
        .swiftmodule: .required,
        .swiftdoc: .required,
        .swiftsourceinfo: .optional,
+        .swiftinterface: .optional,
    ]
 }
@@ -23,11 +23,12 @@ import Zip
 class ZipArtifactCreator {
    /// Location where zip file should be generated
    private let workingDir: URL
+    private let metaWriter: MetaWriter
    private let fileManager: FileManager
-    private let metaEncoder = JSONEncoder()

-    init(workingDir: URL, fileManager: FileManager) {
+    init(workingDir: URL, metaWriter: MetaWriter, fileManager: FileManager) {
        self.workingDir = workingDir
+        self.metaWriter = metaWriter
        self.fileManager = fileManager
    }

@@ -35,18 +36,10 @@ class ZipArtifactCreator {
        let zipURL = workingDir.appendingPathComponent("\(artifactKey).zip")
        try fileManager.createDirectory(at: workingDir, withIntermediateDirectories: true, attributes: nil)
        // Include meta json to the artifact
-        let metaURL = try dumpMeta(meta)
+        let metaURL = try metaWriter.write(meta, locationDir: workingDir)
        let zipPaths = zipContent + [metaURL]

        try Zip.zipFiles(paths: zipPaths, zipFilePath: zipURL, password: nil, progress: nil)
        return Artifact(id: artifactKey, package: zipURL, meta: metaURL)
    }
-
-    // Save meta to a local file
-    private func dumpMeta<T: Meta>(_ meta: T) throws -> URL {
-        let metaURL = workingDir.appendingPathComponent(meta.fileKey).appendingPathExtension("json")
-        let metaData = try metaEncoder.encode(meta)
-        try fileManager.spt_writeToFile(atPath: metaURL.path, contents: metaData)
-        return metaURL
-    }
 }
@@ -52,7 +52,7 @@ class XCLibtoolCreateUniversalBinary: XCLibtoolLogic {
        let config: XCRemoteCacheConfig
        do {
            let srcRoot: URL = URL(fileURLWithPath: fileManager.currentDirectoryPath)
-            config = try XCRemoteCacheConfigReader(srcRootPath: srcRoot.path, fileManager: fileManager)
+            config = try XCRemoteCacheConfigReader(srcRootPath: srcRoot.path, fileReader: fileManager)
                .readConfiguration()
        } catch {
            errorLog("Libtool initialization failed with error: \(error). Fallbacking to libtool")
@@ -33,13 +33,16 @@ enum ThinningCreatorPluginError: Error {
 /// Warning! This plugin assumes that producer's DerivedData are always cleaned before a build
 class ThinningCreatorPlugin: ArtifactCreatorPlugin {
    private let targetTempDir: URL
+    private let modeMarkerPath: String
    private let dirScanner: DirScanner

    /// Default Initializer
    /// - Parameter targetTempDir: Location of current target-specific temp dir (TARGET_TEMP_DIR)
+    /// - Parameter modeMarkerPath: path of maker file that informs if a given target can reuse remote artifacts
    /// - Parameter dirScanner: scanner to access disk and read files and directories hierarchy
-    init(targetTempDir: URL, dirScanner: DirScanner) {
+    init(targetTempDir: URL, modeMarkerPath: String, dirScanner: DirScanner) {
        self.targetTempDir = targetTempDir
+        self.modeMarkerPath = modeMarkerPath
        self.dirScanner = dirScanner
    }

@@ -57,31 +60,19 @@ class ThinningCreatorPlugin: ArtifactCreatorPlugin {
            let fileKey: String
        }
        let uploadedTargetArtifacts = try allURLs.compactMap { tempDir -> TargetTuple? in
-            // All targets that uploaded their artifacts, have it placed in the
-            // `$(TARGET_TEMP_DIR)/xccache/produced/{{fileKey}}.zip` location. Find all targets that have such a file
-
-            let targetGeneratedArtifactRootDir = tempDir
-                .appendingPathComponent("xccache")
-                .appendingPathComponent("produced")
-            guard try dirScanner.itemType(atPath: targetGeneratedArtifactRootDir.path) == ItemType.dir else {
-                // given target didn't generate any artifacts (e.g. it is never cached with XCRemoteCache)
-                return nil
-            }
-
-            let allFilesProduced = try dirScanner.items(at: targetGeneratedArtifactRootDir)
-            let allArtifacts = allFilesProduced.filter { $0.pathExtension == "zip" }
-            guard !allArtifacts.isEmpty else {
+            let potentialArtifacts = try findTargetPackageZip(tempDir: tempDir)
+            guard !potentialArtifacts.isEmpty else {
                // there is no generated *.zip file, so given target didn't create an artifact - it could be
                // just a helper target (like the target we integrate this plugin with)
                return nil
            }
            // Find {{fileKey}} based on the .zip file basename
-            guard allArtifacts.count == 1 else {
+            guard potentialArtifacts.count == 1 else {
                throw ThinningCreatorPluginError.noSingleTargetArtifactsGenerated(
-                    rootDir: targetGeneratedArtifactRootDir
+                    rootDir: tempDir
                )
            }
-            let fileKey = allArtifacts[0].deletingPathExtension().lastPathComponent
+            let fileKey = potentialArtifacts[0].deletingPathExtension().lastPathComponent
            // Taking target name from tempDir, which has a structures "*.build"
            let targetName = tempDir.deletingPathExtension().lastPathComponent
            return TargetTuple(targetName: targetName, fileKey: fileKey)
@@ -96,6 +87,41 @@ class ThinningCreatorPlugin: ArtifactCreatorPlugin {
        return Dictionary(uniqueKeysWithValues: extraKeysTuples)
    }

+    private func findTargetPackageZip(tempDir: URL) throws -> [URL] {
+        // Producer mode:
+        // All targets that uploaded their artifacts, have it placed in the
+        // `$(TARGET_TEMP_DIR)/xccache/produced/{{fileKey}}.zip` location. Find all targets that have such a file
+        // ProducerFast mode:
+        // If a target reused already existing artifact, it still has `$(TARGET_TEMP_DIR)/rc.enabled` marker file
+        // and the reused zip is placed in:
+        // `$(TARGET_TEMP_DIR)/xccache/{{fileKey}}.zip` location
+
+        let targetEnabledMarker = tempDir.appendingPathComponent(modeMarkerPath)
+        let targetReusedArtifactRootDir = tempDir.appendingPathComponent("xccache")
+        let targetGeneratedArtifactRootDir = tempDir
+            .appendingPathComponent("xccache")
+            .appendingPathComponent("produced")
+
+        let pathToDirWithZipArtifacts: URL
+        // try the `.producerFast` scenario first (the artifact was not locally
+        // generated but just reused from the remote cache)
+        if try dirScanner.itemType(atPath: targetEnabledMarker.path) == ItemType.file {
+            pathToDirWithZipArtifacts = targetReusedArtifactRootDir
+        } else {
+            // cover a case when a target was build locally and an artifact
+            // has just been created (locally)
+            guard try dirScanner.itemType(atPath: targetGeneratedArtifactRootDir.path) == ItemType.dir else {
+                // given target didn't generate any artifacts (e.g. it is never cached with XCRemoteCache)
+                return []
+            }
+            pathToDirWithZipArtifacts = targetGeneratedArtifactRootDir
+        }
+
+        let allFilesProduced = try dirScanner.items(at: pathToDirWithZipArtifacts)
+        let allArtifacts = allFilesProduced.filter { $0.pathExtension == "zip" }
+        return allArtifacts
+    }
+
    func artifactToUpload(main: MainArtifactMeta) throws -> [Artifact] {
        return []
    }
@@ -40,7 +40,7 @@ class ThinningDiskSwiftcProductsGenerator: SwiftcProductsGenerator {
        destinationSwiftmodulePaths = Dictionary(
            uniqueKeysWithValues: SwiftmoduleFileExtension.SwiftmoduleExtensions
                .map { ext, _ in
-                    switch (ext) {
+                    switch ext {
                    case .swiftsourceinfo:
                        let dest = modulePathDir.appendingPathComponent("Project")
                            .appendingPathComponent(moduleName)
@@ -25,7 +25,7 @@ class ThinningConsumerPlugin {

    deinit {
        // initialised but never run plugin suggests that standard target fallbacks to the local development
-        // and DerivedData still misses build artifacts.
+        // and DerivedData still misses build artifacts
        guard wasRun else {
            let errorMessage = """
            \(type(of: self)) plugin has never been run, thinning cannot be supported. Verify you \
@@ -41,6 +41,7 @@ class Postbuild {
    private let dSYMOrganizer: DSYMOrganizer
    private let modeController: CacheModeController
    private let metaReader: MetaReader
+    private let metaWriter: MetaWriter
    private let creatorPlugins: [ArtifactCreatorPlugin]
    private let consumerPlugins: [ArtifactConsumerPostbuildPlugin]

@@ -58,6 +59,7 @@ class Postbuild {
        dSYMOrganizer: DSYMOrganizer,
        modeController: CacheModeController,
        metaReader: MetaReader,
+        metaWriter: MetaWriter,
        creatorPlugins: [ArtifactCreatorPlugin],
        consumerPlugins: [ArtifactConsumerPostbuildPlugin]
    ) {
@@ -74,6 +76,7 @@ class Postbuild {
        self.dSYMOrganizer = dSYMOrganizer
        self.modeController = modeController
        self.metaReader = metaReader
+        self.metaWriter = metaWriter
        self.creatorPlugins = creatorPlugins
        self.consumerPlugins = consumerPlugins
    }
@@ -125,6 +128,22 @@ class Postbuild {
        try generateFingerprintOverrides(contextSpecificFingerprint: fingerprint.contextSpecific)
    }

+    /// Uploads only a meta to the remote server - useful when the file artifact (.zip) already exists on a remote
+    /// server and only a meta for a current commit sha has to be uploaded
+    public func performMetaUpload(meta: MainArtifactMeta, for commit: String) throws {
+        // Reset plugins keys as these are unique to each
+        var meta = meta
+        meta.pluginsKeys = [:]
+        meta = try creatorPlugins.reduce(meta) { prevMeta, plugin in
+            var meta = prevMeta
+            // add extra keys from the plugin. A plugin overrides previously defined keys in case of duplication
+            meta.pluginsKeys = try meta.pluginsKeys.merging(plugin.extraMetaKeys(prevMeta), uniquingKeysWith: { $1 })
+            return meta
+        }
+        let metaPath = try metaWriter.write(meta, locationDir: context.targetTempDir)
+        try networkClient.uploadSynchronously(metaPath, as: .meta(commit: commit))
+    }
+
    /// Builds an artifact package and uploads it to the remote server
    public func performBuildUpload(for commit: String) throws {
        let dependencies = try generateDependencies()
@@ -134,7 +153,7 @@ class Postbuild {
        // Replace all local paths to the generic ones (e.g. $SRCROOT)
        let remappers = [remapper] + creatorPlugins.compactMap(\.customPathsRemapper)
        let remapper = DependenciesRemapperComposite(remappers)
-        let abstractFingerprintFiles = remapper.replace(localPaths: dependencies.map(\.path))
+        let abstractFingerprintFiles = try remapper.replace(localPaths: dependencies.map(\.path))
        // TODO: use `inputs` read by dependenciesReader
        var meta = MainArtifactMeta(
            dependencies: abstractFingerprintFiles,
@@ -32,12 +32,15 @@ enum MachOType: String, Codable {
 enum PostbuildContextError: Error {
    /// URL address is not a valid URL
    case invalidAddress(String)
+    /// ARCHS env does not contain any architecture to build
+    case missingArchitecture
 }

 public struct PostbuildContext {
    var mode: Mode
    var targetName: String
    var targetTempDir: URL
+    var derivedFilesDir: URL
    /// Location where all compilation outputs (.o) are placed
    var compilationTempDir: URL
    var configuration: String
@@ -64,6 +67,9 @@ public struct PostbuildContext {
    var machOType: MachOType
    var wasDsymGenerated: Bool
    var dSYMPath: URL
+    // building architecture. Used to find all dependencies from *.d files
+    // Warning: if two architectures are built (e.g. for disabled "Build Archive
+    // Architecture Only"), a first architecture one is picked
    let arch: String
    let builtProductsDir: URL
    /// Location to the product bundle. Can be nil for libraries
@@ -71,18 +77,31 @@ public struct PostbuildContext {
    let derivedSourcesDir: URL
    /// List of all targets to downloaded from the thinning aggregation target
    var thinnedTargets: [String]
-    /// Action type: build, indexbuild etc.
+    /// Action type: build, indexbuild etc
    var action: BuildActionType
+    let modeMarkerPath: String
+    /// location of the json file that define virtual files system overlay
+    /// (mappings of the virtual location file -> local file path)
+    let overlayHeadersPath: URL
+    /// Regexes of files that should not be included in the dependency list
+    let irrelevantDependenciesPaths: [String]
 }

 extension PostbuildContext {
+    // swiftlint:disable:next function_body_length
    init(_ config: XCRemoteCacheConfig, env: [String: String]) throws {
        mode = config.mode
        let targetNameValue: String = try env.readEnv(key: "TARGET_NAME")
        targetName = targetNameValue
        targetTempDir = try env.readEnv(key: "TARGET_TEMP_DIR")
-        arch = try env.readEnv(key: "PLATFORM_PREFERRED_ARCH")
-        compilationTempDir = try env.readEnv(key: "OBJECT_FILE_DIR_normal").appendingPathComponent(arch)
+        derivedFilesDir = try env.readEnv(key: "DERIVED_FILE_DIR")
+        let archs: [String] = try env.readEnv(key: "ARCHS").split(separator: " ").map(String.init)
+        guard let firstArch = archs.first, !firstArch.isEmpty else {
+            throw PostbuildContextError.missingArchitecture
+        }
+        arch = firstArch
+        let variant: String = try env.readEnv(key: "CURRENT_VARIANT")
+        compilationTempDir = try env.readEnv(key: "OBJECT_FILE_DIR_\(variant)").appendingPathComponent(arch)
        configuration = try env.readEnv(key: "CONFIGURATION")
        platform = try env.readEnv(key: "PLATFORM_NAME")
        xcodeBuildNumber = try env.readEnv(key: "XCODE_PRODUCT_BUILD_VERSION")
@@ -106,7 +125,7 @@ extension PostbuildContext {
        dSYMPath = try env.readEnv(key: "DWARF_DSYM_FOLDER_PATH")
            .appendingPathComponent(env.readEnv(key: "DWARF_DSYM_FILE_NAME"))
        builtProductsDir = try env.readEnv(key: "BUILT_PRODUCTS_DIR")
-        if let contentsFolderPath = env.readEnv(key: "CONTENTS_FOLDER_PATH") {
+        if let contentsFolderPath: String = env.readEnv(key: "CONTENTS_FOLDER_PATH") {
            bundleDir = productsDir.appendingPathComponent(contentsFolderPath)
        } else {
            bundleDir = nil
@@ -115,5 +134,9 @@ extension PostbuildContext {
        let thinFocusedTargetsString: String = env.readEnv(key: "SPT_XCREMOTE_CACHE_THINNED_TARGETS") ?? ""
        thinnedTargets = thinFocusedTargetsString.split(separator: ",").map(String.init)
        action = (try? BuildActionType(rawValue: env.readEnv(key: "ACTION"))) ?? .unknown
+        modeMarkerPath = config.modeMarkerPath
+        /// Note: The file has yaml extension, even it is in the json format
+        overlayHeadersPath = targetTempDir.appendingPathComponent("all-product-headers.yaml")
+        irrelevantDependenciesPaths = config.irrelevantDependenciesPaths
    }
 }
@@ -19,6 +19,7 @@

 import Foundation

+// swiftlint:disable type_body_length
 /// Checks current mode from a configuration and based on that:
 /// * triggers build completion
 /// * triggers uploading artifacts to the server for a 'producer' mode
@@ -33,8 +34,9 @@ public class XCPostbuild {
        let context: PostbuildContext
        let cacheHitLogger: CacheHitLogger
        do {
-            config = try XCRemoteCacheConfigReader(env: env, fileManager: fileManager).readConfiguration()
+            config = try XCRemoteCacheConfigReader(env: env, fileReader: fileManager).readConfiguration()
            context = try PostbuildContext(config, env: env)
+            updateProcessTag(context.targetName)
            let counterFactory: FileStatsCoordinator.CountersFactory = { file, count in
                ExclusiveFileCounter(ExclusiveFile(file, mode: .override), countersCount: count)
            }
@@ -66,9 +68,10 @@ public class XCPostbuild {
            // Initialize dependencies
            let primaryGitBranch = GitBranch(repoLocation: config.primaryRepo, branch: config.primaryBranch)
            let gitClient = GitClientImpl(repoRoot: config.repoRoot, primary: primaryGitBranch, shell: shellGetStdout)
-            let pathRemapper = try StringDependenciesRemapper.buildFromEnvs(
-                keys: DependenciesMapping.rewrittenEnvs,
-                envs: env
+            let envsRemapper = try PathDependenciesRemapperFactory().build(
+                orderKeys: DependenciesMapping.rewrittenEnvs + config.customRewriteEnvs,
+                envs: env,
+                customMappings: config.outOfBandMappings
            )
            let envFingerprint = try EnvironmentFingerprintGenerator(
                configuration: config,
@@ -85,6 +88,7 @@ public class XCPostbuild {
                algorithm: MD5Algorithm()
            )
            let organizer = ZipArtifactOrganizer(targetTempDir: context.targetTempDir, fileManager: fileManager)
+            let metaWriter = JsonMetaWriter(fileWriter: fileManager, pretty: config.prettifyMetaFiles)
            let artifactCreator = BuildArtifactCreator(
                buildDir: context.productsDir,
                tempDir: context.targetTempDir,
@@ -92,6 +96,7 @@ public class XCPostbuild {
                moduleName: context.moduleName,
                modulesFolderPath: context.modulesFolderPath,
                dSYMPath: context.dSYMPath,
+                metaWriter: metaWriter,
                fileManager: fileManager
            )
            let dirAccessor = DirAccessorComposer(
@@ -109,6 +114,7 @@ public class XCPostbuild {
                awsV4Signature = AWSV4Signature(
                    secretKey: config.AWSSecretKey,
                    accessKey: config.AWSAccessKey,
+                    securityToken: config.AWSSecurityToken,
                    region: config.AWSRegion,
                    service: config.AWSService,
                    date: Date(timeIntervalSinceNow: 0)
@@ -117,6 +123,7 @@ public class XCPostbuild {
            let networkClient = NetworkClientImpl(
                session: sessionFactory.build(),
                retries: config.uploadRetries,
+                retryDelay: config.retryDelay,
                fileManager: fileManager,
                awsV4Signature: awsV4Signature
            )
@@ -142,12 +149,32 @@ public class XCPostbuild {
                fileDependeciesReaderFactory: fileReaderFactory,
                dirScanner: fileManager
            )
+            var remappers: [DependenciesRemapper] = []
+            if !config.disableVFSOverlay {
+                // As the PostbuildContext assumes file location and filename (`all-product-headers.yaml`)
+                // do not fail in case of a missing headers overlay file. In the future, all overlay files could be
+                // captured from the swiftc invocation similarly is stored in the `history.compile`
+                // for the consumer mode
+                let overlayReader = JsonOverlayReader(
+                    context.overlayHeadersPath,
+                    mode: .bestEffort,
+                    fileReader: fileManager
+                )
+                let overlayRemapper = OverlayDependenciesRemapper(
+                    overlayReader: overlayReader
+                )
+                remappers.append(overlayRemapper)
+            }
+            remappers.append(envsRemapper)
+            let pathRemapper = DependenciesRemapperComposite(remappers)
            let dependencyProcessor = DependencyProcessorImpl(
                xcode: context.xcodeDir,
                product: context.productsDir,
                source: context.srcRoot,
                intermediate: context.targetTempDir,
-                bundle: context.bundleDir
+                derivedFiles: context.derivedFilesDir,
+                bundle: context.bundleDir,
+                skippedRegexes: context.irrelevantDependenciesPaths
            )
            // Override fingerprints for all produced '.swiftmodule' files
            let fingerprintOverrideManager = FingerprintOverrideManagerImpl(
@@ -205,9 +232,10 @@ public class XCPostbuild {
                            worker: DispatchGroupParallelizationWorker(qos: .userInitiated)
                        )
                        consumerPlugins.append(thinningPlugin)
-                    case .producer:
+                    case .producer, .producerFast:
                        let thinningPlugin = ThinningCreatorPlugin(
                            targetTempDir: context.targetTempDir,
+                            modeMarkerPath: context.modeMarkerPath,
                            dirScanner: fileManager
                        )
                        creatorPlugins.append(thinningPlugin)
@@ -229,6 +257,7 @@ public class XCPostbuild {
                dSYMOrganizer: dSYMOrganizer,
                modeController: modeController,
                metaReader: metaReader,
+                metaWriter: metaWriter,
                creatorPlugins: creatorPlugins,
                consumerPlugins: consumerPlugins
            )
@@ -243,11 +272,22 @@ public class XCPostbuild {
                try postbuildAction.deleteFingerprintOverrides()
            }

+
            // Trigger uploading the artifact
-            if context.mode == .producer {
+            switch (context.mode, try modeController.isEnabled(), context.remoteCommit) {
+            case (.producerFast, true, .available(commit: let commitToReuse)):
+                // Upload only updated meta. Artifact zip is already on a remote server
+                let referenceCommit = try config.publishingSha ?? gitClient.getCurrentSha()
+                let metaData = try remoteNetworkClient.fetch(.meta(commit: commitToReuse))
+                let meta = try metaReader.read(data: metaData)
+                try postbuildAction.performMetaUpload(meta: meta, for: referenceCommit)
+            case (.producer, _, _), (.producerFast, _, _):
                // Generate artifacts and upload to the remote server for a reference sha
                let referenceCommit = try config.publishingSha ?? gitClient.getCurrentSha()
                try postbuildAction.performBuildUpload(for: referenceCommit)
+            default:
+                // Consumer does not upload anything
+                break
            }

            let executableURL = context.productsDir.appendingPathComponent(context.executablePath)
@@ -261,9 +301,8 @@ public class XCPostbuild {
            } else {
                try postbuildAction.performBuildCleanup()
                try cacheHitLogger.logMiss()
-                // Producer mode doesn't use cached artifacts so modeController is not enabled. If producer
-                // reaches this point, there were no issues with publishing
-                let actionName = context.mode == .producer ? "Published" : "Disabled"
+                // If producers reach this point, there were no issues with publishing
+                let actionName = context.mode == .consumer ? "Disabled" : "Published"
                printToUser("\(actionName) remote cache for \(context.targetName)")
            }
        } catch PluginError.unrecoverableError(let error) {
@@ -286,3 +325,4 @@ public class XCPostbuild {
        }
    }
 }
+// swiftlint:enable type_body_length
@@ -55,6 +55,7 @@ class Prebuild {
        self.artifactConsumerPrebuildPlugins = artifactConsumerPrebuildPlugins
    }

+    // swiftlint:disable:next function_body_length
    public func perform() throws -> PrebuildResult {
        guard case .available(let commit) = context.remoteCommit else {
            return .incompatible
@@ -62,7 +63,9 @@ class Prebuild {
        do {
            let metaData = try networkClient.fetch(.meta(commit: commit))
            let meta = try metaReader.read(data: metaData)
-            let localDependencies = remapper.replace(genericPaths: meta.dependencies).map(URL.init(fileURLWithPath:))
+            let localDependencies = try remapper.replace(
+                genericPaths: meta.dependencies
+            ).map(URL.init(fileURLWithPath:))
            let localFingerprint = try generateFingerprint(for: localDependencies)
            if localFingerprint.raw != meta.rawFingerprint {
                if context.forceCached {
@@ -43,6 +43,9 @@ public struct PrebuildContext {
    let targetName: String
    /// List of all targets to downloaded from the thinning aggregation target
    var thinnedTargets: [String]?
+    /// location of the json file that define virtual files system overlay
+    /// (mappings of the virtual location file -> local file path)
+    let overlayHeadersPath: URL
 }

 extension PrebuildContext {
@@ -64,5 +67,7 @@ extension PrebuildContext {
        self.targetName = targetName
        let thinFocusedTargetsString: String? = env.readEnv(key: "SPT_XCREMOTE_CACHE_THINNED_TARGETS")
        thinnedTargets = thinFocusedTargetsString?.split(separator: ",").map(String.init)
+        /// Note: The file has yaml extension, even it is in the json format
+        overlayHeadersPath = targetTempDir.appendingPathComponent("all-product-headers.yaml")
    }
 }
@@ -29,8 +29,9 @@ public class XCPrebuild {
        let config: XCRemoteCacheConfig
        let context: PrebuildContext
        do {
-            config = try XCRemoteCacheConfigReader(env: env, fileManager: fileManager).readConfiguration()
+            config = try XCRemoteCacheConfigReader(env: env, fileReader: fileManager).readConfiguration()
            context = try PrebuildContext(config, env: env)
+            updateProcessTag(context.targetName)
        } catch {
            // Fatal error:
            exit(1, "FATAL: Prebuild initialization failed with error: \(error)")
@@ -77,6 +78,10 @@ public class XCPrebuild {
            exit(0)
        }

+        let compilationHistoryOrganizer = CompilationHistoryFileOrganizer(
+            context.compilationHistoryFile,
+            fileManager: fileManager
+        )
        do {
            let envFingerprint = try EnvironmentFingerprintGenerator(
                configuration: config,
@@ -95,6 +100,7 @@ public class XCPrebuild {
                awsV4Signature = AWSV4Signature(
                    secretKey: config.AWSSecretKey,
                    accessKey: config.AWSAccessKey,
+                    securityToken: config.AWSSecurityToken,
                    region: config.AWSRegion,
                    service: config.AWSService,
                    date: Date(timeIntervalSinceNow: 0)
@@ -103,6 +109,7 @@ public class XCPrebuild {
            let networkClient = NetworkClientImpl(
                session: sessionFactory.build(),
                retries: config.downloadRetries,
+                retryDelay: config.retryDelay,
                fileManager: fileManager,
                awsV4Signature: awsV4Signature
            )
@@ -115,10 +122,27 @@ public class XCPrebuild {
            )
            let client: NetworkClient = config.disableHttpCache ? networkClient : cacheNetworkClient
            let remoteNetworkClient = RemoteNetworkClientImpl(client, urlBuilder)
-            let pathRemapper = try StringDependenciesRemapper.buildFromEnvs(
-                keys: DependenciesMapping.rewrittenEnvs,
-                envs: env
+            let envsRemapper = try PathDependenciesRemapperFactory().build(
+                orderKeys: DependenciesMapping.rewrittenEnvs + config.customRewriteEnvs,
+                envs: env,
+                customMappings: config.outOfBandMappings
            )
+            var remappers: [DependenciesRemapper] = []
+            if !config.disableVFSOverlay {
+                // As PrebuildContext assumes file location and its filename (`all-product-headers.yaml`)
+                // do not fail in case of a missing headers overlay file
+                let overlayReader = JsonOverlayReader(
+                    context.overlayHeadersPath,
+                    mode: .bestEffort,
+                    fileReader: fileManager
+                )
+                let overlayRemapper = OverlayDependenciesRemapper(
+                    overlayReader: overlayReader
+                )
+                remappers.append(overlayRemapper)
+            }
+            remappers.append(envsRemapper)
+            let pathRemapper = DependenciesRemapperComposite(remappers)
            let filesFingerprintGenerator = FingerprintAccumulatorImpl(
                algorithm: MD5Algorithm(),
                fileManager: fileManager
@@ -129,7 +153,6 @@ public class XCPrebuild {
                algorithm: MD5Algorithm()
            )
            let organizer = ZipArtifactOrganizer(targetTempDir: context.targetTempDir, fileManager: fileManager)
-            let compilationHistoryOrganizer = CompilationHistoryFileOrganizer(context.compilationHistoryFile, fileManager: fileManager)
            let metaReader = JsonMetaReader(fileAccessor: fileManager)
            var consumerPlugins: [ArtifactConsumerPrebuildPlugin] = []

@@ -167,7 +190,6 @@ public class XCPrebuild {
            case .compatible(localDependencies: let dependencies):
                // TODO: pass `allowedInputFiles` observed in the build time
                try modeController.enable(allowedInputFiles: dependencies, dependencies: dependencies)
-                compilationHistoryOrganizer.reset()
            }
        } catch {
            disableRemoteCache(
@@ -175,6 +197,7 @@ public class XCPrebuild {
                errorMessage: "Prebuild step failed with error: \(error)"
            )
        }
+        compilationHistoryOrganizer.reset()
    }

    private func disableRemoteCache(modeController: PhaseCacheModeController, errorMessage: String?) {
@@ -72,13 +72,24 @@ class TemplateBasedCCWrapperBuilder: CCWrapperBuilder {
        )
        infoLog("ClangWrapperBuilder compiles file at \(compilationFile).")
        // -O3: optimize for faster execution
-        let args = [clangCommand, "-O3", compilationFile.path, "-o", destination.path]
+        let args = [
+            clangCommand,
+            "-arch",
+            "arm64",
+            "-arch",
+            "x86_64",
+            "-O3",
+            compilationFile.path,
+            "-o",
+            destination.path,
+        ]
        let compilationOutput = try shell("xcrun", args, URL(fileURLWithPath: "").path, nil)
        infoLog("Clang compilation output: \(compilationOutput)")
    }


    /// Generates source of the cc wrapper
+    // swiftlint:disable line_length
    // swiftlint:disable:next function_body_length
    private func buildWrapperSource(clangCommand: String, markerFilename: String, commitSha: String) -> String {
        return """
@@ -384,6 +395,8 @@ class TemplateBasedCCWrapperBuilder: CCWrapperBuilder {
            const char *dependency_arg_name = "-MF";
            const char *output_arg_name = "-o";
            const char *serialize_diagnostics_arg_name = "--serialize-diagnostics";
+            const char *language_mode_arg_name = "-x";
+            const char *precompile_header_arg_value = "objective-c-header";
            const char *clang_cmd = "\(clangCommand)";
            const char *markerFile = "\(markerFilename)";
            const char *compilationHistoryFile = "\(compilationHistoryFilename)";
@@ -398,6 +411,7 @@ class TemplateBasedCCWrapperBuilder: CCWrapperBuilder {
            const char *output_file= NULL;
            const char *input_file = NULL;
            const char *diagnostics_file = NULL;
+            const char *language_mode = NULL;

            for (int i = 1; i < argc; i++) {
                if (strcmp(argv[i], dependency_arg_name) == 0 && i < (argc - 1) ) {
@@ -418,6 +432,12 @@ class TemplateBasedCCWrapperBuilder: CCWrapperBuilder {
                    i += 1;
                    clang_args[i] = argv[i];
                    diagnostics_file = argv[i];
+                } if (strcmp(argv[i], language_mode_arg_name) == 0 && i < (argc - 1) ) {
+                    // called with "-x path" pattern and not the last argument
+                    clang_args[i] = argv[i];
+                    i += 1;
+                    clang_args[i] = argv[i];
+                    language_mode = argv[i];
                } else if (
                    isSuffixed(argv[i],".m") ||
                    isSuffixed(argv[i],".mm") ||
@@ -425,10 +445,13 @@ class TemplateBasedCCWrapperBuilder: CCWrapperBuilder {
                    isSuffixed(argv[i],".cc") ||
                    isSuffixed(argv[i],".cpp") ||
                    isSuffixed(argv[i],".c++") ||
-                    isSuffixed(argv[i],".cxx")
+                    isSuffixed(argv[i],".cxx") ||
+                    isSuffixed(argv[i],".S") ||
+                    isSuffixed(argv[i],".s")
                ) {
                    // a full list of extensions is taken from https://clang.llvm.org/docs/ClangFormatStyleOptions.html
                    // support for .m,.mm,.c,.cc,.cpp,.c++,.cxx input files
+                    // .s and .S are assembly files
                    clang_args[i] = argv[i];
                    input_file = argv[i];
                } else {
@@ -437,6 +460,14 @@ class TemplateBasedCCWrapperBuilder: CCWrapperBuilder {
                }
            }

+           // null-terminating the args array needed for local compilation fallback
+           clang_args[argc] = NULL;
+
+           // Verify mode. Even a target is cached, pch mode is not supported. Fallback to the local compilation
+           if (language_mode != NULL && strcmp(language_mode, precompile_header_arg_value) == 0) {
+               return execvp(clang_cmd, (char *const*) clang_args);
+           }
+
           // Verify all input arguments
           if (dependency_file == NULL) {
               fprintf(stderr, "error: missing %s input\\n", dependency_arg_name);
@@ -507,8 +538,6 @@ class TemplateBasedCCWrapperBuilder: CCWrapperBuilder {
               }
           }

-           // null-terminating the args array
-           clang_args[argc] = NULL;
           #pragma GCC diagnostic push
           #pragma GCC diagnostic ignored "-Wincompatible-pointer-types-discards-qualifiers"
           /// execvp takes $PATH to consideration
@@ -516,5 +545,5 @@ class TemplateBasedCCWrapperBuilder: CCWrapperBuilder {
           #pragma GCC diagnostic pop
        }
        """
-    } // swiftlint:disable:next file_length
-}
+    } // swiftlint:disable:next file_length line_length
+} // swiftlint:enable line_length
@@ -33,15 +33,18 @@ protocol BuildSettingsIntegrateAppender {
 class XcodeProjBuildSettingsIntegrateAppender: BuildSettingsIntegrateAppender {
    private let mode: Mode
    private let repoRoot: URL
+    private let fakeSrcRoot: URL

-    init(mode: Mode, repoRoot: URL) {
+    init(mode: Mode, repoRoot: URL, fakeSrcRoot: URL) {
        self.mode = mode
        self.repoRoot = repoRoot
+        self.fakeSrcRoot = fakeSrcRoot
    }

    func appendToBuildSettings(buildSettings: BuildSettings, wrappers: XCRCBinariesPaths) -> BuildSettings {
        var result = buildSettings
        result["SWIFT_EXEC"] = wrappers.swiftc.path
+        result["SWIFT_USE_INTEGRATED_DRIVER"] = "NO"
        // When generating artifacts, no need to shell-out all compilation commands to our wrappers
        if case .consumer = mode {
            result["CC"] = wrappers.cc.path
@@ -61,7 +64,11 @@ class XcodeProjBuildSettingsIntegrateAppender: BuildSettingsIntegrateAppender {
        result["OTHER_SWIFT_FLAGS"] = swiftFlags.settingValue
        result["OTHER_CFLAGS"] = clangFlags.settingValue

-        result["XCRC_FAKE_SRCROOT"] = "/\(String(repeating: "x", count: 10))"
+        result["XCRC_FAKE_SRCROOT"] = "\(fakeSrcRoot.path)"
+        result["XCRC_PLATFORM_PREFERRED_ARCH"] =
+        """
+        $(LINK_FILE_LIST_$(CURRENT_VARIANT)_$(PLATFORM_PREFERRED_ARCH):dir:standardizepath:file:default=arm64)
+        """
        return result
    }
 }
@@ -35,7 +35,7 @@ struct IncludeExcludeOracle: IncludeOracle {


    func shouldInclude(identifier: OracleIdentifierType) -> Bool {
-        // exclude array has precedence.
+        // exclude array has precedence
        if excludes.contains(identifier) {
            return false
        }
@@ -53,6 +53,7 @@ extension IntegrateContext {
            swiftc: binariesDir.appendingPathComponent("xcswiftc"),
            libtool: binariesDir.appendingPathComponent("xclibtool"),
            ld: binariesDir.appendingPathComponent("xcld"),
+            ldplusplus: binariesDir.appendingPathComponent("xcldplusplus"),
            prebuild: binariesDir.appendingPathComponent("xcprebuild"),
            postbuild: binariesDir.appendingPathComponent("xcpostbuild")
        )
@@ -56,7 +56,7 @@ class FileLLDBInitPatcher: LLDBInitPatcher {
    }

    private func findIndices(in collection: [String], value: String) -> [Int] {
-        collection.enumerated().reduce([]) { (result, line) -> [Int] in
+        collection.enumerated().reduce([]) { result, line -> [Int] in
            if line.element == Self.preambleString {
                return result + [line.offset]
            }
@@ -75,7 +75,7 @@ class FileLLDBInitPatcher: LLDBInitPatcher {
            var contentLines = originalContentLines
            let preambleIndices = findIndices(in: contentLines, value: Self.preambleString)

-            if preambleIndices.count > 0 {
+            if !preambleIndices.isEmpty {
                let firstLLDBCommandIndex = preambleIndices[0] + 1
                if firstLLDBCommandIndex >= contentLines.count {
                    // corrupted file, append the script line at the bottom
@@ -64,6 +64,7 @@ public class XCIntegrate {
        self.output = output
    }

+    // swiftlint:disable:next function_body_length
    public func main() {
        do {
            let env = ProcessInfo.processInfo.environment
@@ -73,7 +74,7 @@ public class XCIntegrate {
            let binariesDir = commandURL.deletingLastPathComponent()

            let srcRoot: URL = URL(fileURLWithPath: projectPath).deletingLastPathComponent()
-            let config = try XCRemoteCacheConfigReader(srcRootPath: srcRoot.path, fileManager: fileManager)
+            let config = try XCRemoteCacheConfigReader(srcRootPath: srcRoot.path, fileReader: fileManager)
                .readConfiguration()

            let context = try IntegrateContext(
@@ -96,7 +97,8 @@ public class XCIntegrate {
            )
            let buildSettingsAppender = XcodeProjBuildSettingsIntegrateAppender(
                mode: context.mode,
-                repoRoot: context.repoRoot
+                repoRoot: context.repoRoot,
+                fakeSrcRoot: context.fakeSrcRoot
            )
            let lldbPatcher: LLDBInitPatcher
            switch lldbMode {
@@ -114,7 +116,7 @@ public class XCIntegrate {

            let integrator = XcodeProjIntegrate(
                project: context.projectPath,
-                mode:context.mode,
+                mode: context.mode,
                binaries: context.binaries,
                configurationIncludeOracle: configurationOracle,
                targetIncludeOracle: targetOracle,
@@ -26,6 +26,7 @@ struct XCRCBinariesPaths {
    let swiftc: URL
    let libtool: URL
    let ld: URL
+    let ldplusplus: URL
    let prebuild: URL
    let postbuild: URL
 }
@@ -100,11 +100,11 @@ struct XcodeProjIntegrate: Integrate {
            outputPaths: [
                """
                $(TARGET_BUILD_DIR)/$(MODULES_FOLDER_PATH)/$(PRODUCT_MODULE_NAME).swiftmodule/\
-                $(PLATFORM_PREFERRED_ARCH).swiftmodule.md5
+                $(XCRC_PLATFORM_PREFERRED_ARCH).swiftmodule.md5
                """,
                """
                $(TARGET_BUILD_DIR)/$(MODULES_FOLDER_PATH)/$(PRODUCT_MODULE_NAME).swiftmodule/\
-                $(PLATFORM_PREFERRED_ARCH)-$(LLVM_TARGET_TRIPLE_VENDOR)-$(SWIFT_PLATFORM_TARGET_PREFIX)\
+                $(XCRC_PLATFORM_PREFERRED_ARCH)-$(LLVM_TARGET_TRIPLE_VENDOR)-$(SWIFT_PLATFORM_TARGET_PREFIX)\
                $(LLVM_TARGET_TRIPLE_SUFFIX).swiftmodule.md5
                """,
            ],
@@ -114,7 +114,9 @@ struct XcodeProjIntegrate: Integrate {
        markPhase = PBXShellScriptBuildPhase(
            name: "\(Self.BuildStepPrefix)RemoteCache_mark",
            inputPaths: [binaries.prepare.path],
-            shellScript: "\"$SCRIPT_INPUT_FILE_0\" mark --configuration \"$CONFIGURATION\" --platform \"$PLATFORM_NAME\""
+            shellScript:
+                "\"$SCRIPT_INPUT_FILE_0\" mark " +
+                "--configuration \"$CONFIGURATION\" --platform \"$PLATFORM_NAME\""
        )
    }

@@ -129,6 +131,7 @@ struct XcodeProjIntegrate: Integrate {
        try encodedYAML.write(to: configOverrideLocation, atomically: false, encoding: .utf8)
    }

+    // swiftlint:disable:next function_body_length
    func run() throws {
        let outputFile = output ?? projectURL
        let projectRoot = projectURL.deletingLastPathComponent()
@@ -224,13 +227,15 @@ struct XcodeProjIntegrate: Integrate {
        let previousRCPhases = target.buildPhases.filter(isRCPhase)
        target.buildPhases.removeAll(where: previousRCPhases.contains)

-        if target.buildPhases.map(\.buildPhase).contains(.sources) {
+        if let sourceIndex = target.buildPhases.map(\.buildPhase).firstIndex(of: .sources) {
            // add (pre|post)build phases only when a target has some compilation steps
            // otherwise they make no sense (nothing to store in an artifact)
-            pbxproj.add(object: prebuildPhase)
-            target.buildPhases.insert(prebuildPhase, at: 0)
+            // add postbuild right after compilation as custom build steps may depend on files generated by
+            // the xcpostbuild (e.g. to copy -Swift.h.md5)
            pbxproj.add(object: postbuildPhase)
-            target.buildPhases.append(postbuildPhase)
+            target.buildPhases.insert(postbuildPhase, at: sourceIndex + 1)
+            pbxproj.add(object: prebuildPhase)
+            target.buildPhases.insert(prebuildPhase, at: sourceIndex)
        }
    }

@@ -100,7 +100,7 @@ struct XcodeSettingsCFlags: XcodeSettingsFlags {
        case (.some(let existing), _):
            var flagsComponents: [String] = existing.split(separator: " ").map(String.init)
            // remove (if exists)
-            let existingFlagIndex = flagsComponents.firstIndex { (component) -> Bool in
+            let existingFlagIndex = flagsComponents.firstIndex { component -> Bool in
                component.hasPrefix("\(Self.prefix)\(key)=")
            }
            if let index = existingFlagIndex {
@@ -18,7 +18,6 @@
 // under the License.

 import Foundation
-import Yams

 /// Print current configuration to the console
 public class XCConfig {
@@ -33,7 +32,7 @@ public class XCConfig {
        let fileManager = FileManager.default
        let config: XCRemoteCacheConfig
        do {
-            config = try XCRemoteCacheConfigReader(env: env, fileManager: fileManager).readConfiguration()
+            config = try XCRemoteCacheConfigReader(env: env, fileReader: fileManager).readConfiguration()
        } catch {
            exit(1, "FATAL: Prepare initialization failed with error: \(error)")
        }
@@ -18,7 +18,6 @@
 // under the License.

 import Foundation
-import Yams

 /// Switch between Online/Offline modes
 public enum XCPrepareMode {
@@ -62,7 +61,7 @@ public class XCPrepare {
        var context: PrepareContext
        let xcodeVersion: String
        do {
-            config = try XCRemoteCacheConfigReader(env: env, fileManager: fileManager).readConfiguration()
+            config = try XCRemoteCacheConfigReader(env: env, fileReader: fileManager).readConfiguration()
            context = try PrepareContext(config, offline: offline)
            xcodeVersion = try customXcodeBuildNumber ?? XcodeProbeImpl(shell: shellGetStdout).read().buildVersion
        } catch {
@@ -79,6 +78,7 @@ public class XCPrepare {
                awsV4Signature = AWSV4Signature(
                    secretKey: config.AWSSecretKey,
                    accessKey: config.AWSAccessKey,
+                    securityToken: config.AWSSecurityToken,
                    region: config.AWSRegion,
                    service: config.AWSService,
                    date: Date(timeIntervalSinceNow: 0)
@@ -87,6 +87,7 @@ public class XCPrepare {
            let networkClient = NetworkClientImpl(
                session: sessionFactory.build(),
                retries: config.downloadRetries,
+                retryDelay: config.retryDelay,
                fileManager: fileManager,
                awsV4Signature: awsV4Signature
            )
@@ -38,6 +38,7 @@ public class XCPrepareMark {
        self.commit = commit
    }

+    // swiftlint:disable:next function_body_length
    public func main() {
        let env = ProcessInfo.processInfo.environment
        let fileManager = FileManager.default
@@ -45,7 +46,7 @@ public class XCPrepareMark {
        let context: PrepareMarkContext
        let xcodeVersion: String
        do {
-            config = try XCRemoteCacheConfigReader(env: env, fileManager: fileManager).readConfiguration()
+            config = try XCRemoteCacheConfigReader(env: env, fileReader: fileManager).readConfiguration()
            context = try PrepareMarkContext(config)
            xcodeVersion = try xcode ?? XcodeProbeImpl(shell: shellGetStdout).read().buildVersion
        } catch {
@@ -59,6 +60,7 @@ public class XCPrepareMark {
                awsV4Signature = AWSV4Signature(
                    secretKey: config.AWSSecretKey,
                    accessKey: config.AWSAccessKey,
+                    securityToken: config.AWSSecurityToken,
                    region: config.AWSRegion,
                    service: config.AWSService,
                    date: Date(timeIntervalSinceNow: 0)
@@ -67,6 +69,7 @@ public class XCPrepareMark {
            let networkClient = NetworkClientImpl(
                session: sessionFactory.build(),
                retries: config.uploadRetries,
+                retryDelay: config.retryDelay,
                fileManager: fileManager,
                awsV4Signature: awsV4Signature
            )
@@ -18,7 +18,6 @@
 // under the License.

 import Foundation
-import Yams

 /// Manages XCRemoteCache statistics: rests, print to the standard output etc
 public class XCStats {
@@ -37,7 +36,7 @@ public class XCStats {
        let config: XCRemoteCacheConfig
        let context: XCStatsContext
        do {
-            config = try XCRemoteCacheConfigReader(env: env, fileManager: fileManager).readConfiguration()
+            config = try XCRemoteCacheConfigReader(env: env, fileReader: fileManager).readConfiguration()
            try context = XCStatsContext(config, fileManager: fileManager)
        } catch {
            exit(1, "FATAL: Prepare initialization failed with error: \(error)")
@@ -70,7 +70,7 @@ public class XCCreateBinary {
        let config: XCRemoteCacheConfig
        do {
            let srcRoot: URL = URL(fileURLWithPath: fileManager.currentDirectoryPath)
-            config = try XCRemoteCacheConfigReader(srcRootPath: srcRoot.path, fileManager: fileManager)
+            config = try XCRemoteCacheConfigReader(srcRootPath: srcRoot.path, fileReader: fileManager)
                .readConfiguration()
        } catch {
            errorLog("\(stepDescription) initialization failed with error: \(error). Fallbacking to \(fallbackCommand)")
@@ -120,9 +120,9 @@ class Swiftc: SwiftcProtocol {
                let prebuildDiscoveryURL = context.tempDir.appendingPathComponent(context.prebuildDependenciesPath)
                let prebuildDiscoverWriter = dependenciesWriterFactory(prebuildDiscoveryURL, fileManager)
                try prebuildDiscoverWriter.write(skipForSha: remoteCommit)
-            case .consumer, .producer:
-                // Never skips prebuild phase and fallbacks to the swiftc compilation for:
-                // 1) Not enabled remote cache or 2) producer
+            case .consumer, .producer, .producerFast:
+                // Never skip prebuild phase and fallback to the swiftc compilation for:
+                // 1) Not enabled remote cache, 2) producer(s)
                break
            }
            return .forceFallback
@@ -24,6 +24,8 @@ public struct SwiftcContext {
        case producer
        /// Commit sha of the commit to use during remote cache
        case consumer(commit: RemoteCommitInfo)
+        /// Remote artifact exists and can be optimistically used in place of a local compilation
+        case producerFast
    }

    let objcHeaderOutput: URL
@@ -74,6 +76,14 @@ public struct SwiftcContext {
            mode = .consumer(commit: remoteCommit)
        case .producer:
            mode = .producer
+        case .producerFast:
+            let remoteCommit = RemoteCommitInfo(try? String(contentsOf: remoteCommitLocation).trim())
+            switch remoteCommit {
+            case .unavailable:
+                mode = .producer
+            case .available:
+                mode = .producerFast
+            }
        }
        invocationHistoryFile = URL(fileURLWithPath: config.compilationHistoryFile, relativeTo: tempDir)
    }
@@ -110,12 +110,18 @@ class SwiftcOrchestrator {
                    try invocationStorage.store(args: invocationArgs)
                }
            } catch {
-                // The critical section is protected by a lock. Some other process already called compilation history.
-                // We only need to call our current step then.
+                // The critical section is protected by a lock. Some other process already called compilation history
+                // We only need to call our current step then
                fallbackToDefault(command: swiftcCommand)
            }
        case .consumer:
            fallbackToDefault(command: swiftcCommand)
+        case .producerFast:
+            let compileStepResult = try swiftc.mockCompilation()
+            if case .forceFallback = compileStepResult {
+                // cannot reuse cached artifact. Build it locally and upload to the server just as for the producer
+                fallthrough
+            }
        case .producer:
            var swiftcArgs = ProcessInfo().arguments
            swiftcArgs = try producerFallbackCommandProcessors.reduce(swiftcArgs) { args, processor in
@@ -20,7 +20,7 @@
 import Foundation

 enum DiskSwiftcProductsGeneratorError: Error {
-    /// When a generator was asked to generate unknown swiftmodule extension file.
+    /// When a generator was asked to generate unknown swiftmodule extension file
    /// Probably a programmer error: asking to generate excessive extensions, not listed in
    /// `SwiftmoduleFileExtension.SwiftmoduleExtensions`
    case unknownSwiftmoduleFile
@@ -70,7 +70,7 @@ public class XCSwiftc {
        let context: SwiftcContext
        do {
            let srcRoot: URL = URL(fileURLWithPath: fileManager.currentDirectoryPath)
-            config = try XCRemoteCacheConfigReader(srcRootPath: srcRoot.path, fileManager: fileManager)
+            config = try XCRemoteCacheConfigReader(srcRootPath: srcRoot.path, fileReader: fileManager)
                .readConfiguration()
            context = try SwiftcContext(config: config, input: inputArgs)
        } catch {
@@ -101,7 +101,10 @@ public class XCSwiftc {
            objcHeaderOutput: context.objcHeaderOutput,
            diskCopier: HardLinkDiskCopier(fileManager: fileManager)
        )
-        let allInvocationsStorage = ExistingFileStorage(storageFile: context.invocationHistoryFile, command: swiftcCommand)
+        let allInvocationsStorage = ExistingFileStorage(
+            storageFile: context.invocationHistoryFile,
+            command: swiftcCommand
+        )
        // When fallbacking to local compilation do not call historical `swiftc` invocations
        // The current fallback invocation already compiles all files in a target
        let invocationStorage = FilteredInvocationStorage(
@@ -20,4 +20,5 @@
 public enum Mode: String, Codable, CaseIterable {
    case consumer
    case producer
+    case producerFast = "producer-fast"
 }
@@ -83,6 +83,8 @@ public struct XCRemoteCacheConfig: Encodable {
    var downloadRetries: Int = 0
    /// Number of retries for upload requests
    var uploadRetries: Int = 3
+    /// Delay between retries in seconds
+    var retryDelay: Double = 10.0
    /// Extra headers appended to all remote HTTP(S) requests
    var requestCustomHeaders: [String: String] = [:]
    /// Filename (without an extension) of the compilation input file that is used
@@ -94,10 +96,11 @@ public struct XCRemoteCacheConfig: Encodable {
    var focusedTargets: [String] = []
    ///  Disable cache for http requests to fecth metadata and download artifacts
    var disableHttpCache: Bool = false
-    /// Path, relative to $TARGET_TEMP_DIR which gathers all compilation commands that should be executed if a target
-    /// switches to local compilation. Example: A new `.swift` file invalidates remote artifact and triggers local compilation
-    /// When that happens, all previously skipped clang build steps need to be eventually called locally - this file lists
-    /// all these commands.
+    /// Path, relative to $TARGET_TEMP_DIR which gathers all compilation commands that should be e
+    /// xecuted if a target switches to local compilation
+    /// Example: A new `.swift` file invalidates remote arXcodeProjIntegrate.swifttifact and triggers local compilation
+    /// When that happens, all previously skipped clang build steps
+    /// need to be eventually called locally - this file lists all these commands
    var compilationHistoryFile: String = "history.compile"
    /// Timeout for remote response data interval (in seconds). If an interval between data chunks is
    /// longer than a timeout, a request fails
@@ -111,19 +114,43 @@ public struct XCRemoteCacheConfig: Encodable {
    var thinningEnabled: Bool = false
    /// Module name of a target that works as a helper for thinned targets
    var thinningTargetModuleName: String = "ThinningRemoteCacheModule"
+    /// Opt-in pretty json formatting for meta files
+    var prettifyMetaFiles: Bool = false
    /// Secret key for AWS V4 Signature, if this is set the Authentication Header will be added
    var AWSSecretKey: String = ""
    /// Access key for AWS V4 Signature
    var AWSAccessKey: String = ""
+    /// Temporary security token provided by the AWS Security Token Service
+    var AWSSecurityToken: String?
    /// Region for AWS V4 Signature (e.g. `eu`)
    var AWSRegion: String = ""
    /// Service for AWS V4 Signature (e.g. `storage`)
    var AWSService: String = ""
+    /// A dictionary of files path remapping that should be applied to make it absolute path agnostic on a list of
+    /// dependencies. Useful if a project refers files out of repo root, either compilation files or precompiled
+    /// dependencies. Keys represent generic replacement and values are substrings that should be replaced
+    /// Example: for mapping `["COOL_LIBRARY": "/CoolLibrary"]`
+    /// `/CoolLibrary/main.swift`will be represented as `$(COOL_LIBRARY)/main.swift`)
+    /// Warning: remapping order is not-deterministic so avoid remappings with multiple matchings
+    var outOfBandMappings: [String: String] = [:]
+    /// If true, SSL certificate validation is disabled
+    var disableCertificateVerification: Bool = false
+    /// A feature flag to disable virtual file system overlay support (temporary)
+    var disableVFSOverlay: Bool = false
+    /// A list of extra ENVs that should be used as placeholders in the dependency list
+    /// ENV rewrite process is optimistic - does nothing if an ENV is not defined in the pre/postbuild process
+    var customRewriteEnvs: [String] = []
+    /// Regexes of files that should not be included in a list of dependencies. Warning! Add entries here
+    /// with caution - excluding dependencies that are relevant might lead to a target overcaching
+    /// Note: The regex can match either partially or fully the filepath, e.g. `\\.modulemap$` will exclude
+    /// all `.modulemap` files
+    var irrelevantDependenciesPaths: [String] = []
 }

 extension XCRemoteCacheConfig {
    /// Merges existing config with the other config and returns a final result
    /// `other` scheme overrides existing configuration
+    // swiftlint:disable:next function_body_length
    func merged(with scheme: ConfigFileScheme) -> XCRemoteCacheConfig {
        var merge = self
        merge.mode = scheme.mode ?? mode
@@ -150,6 +177,7 @@ extension XCRemoteCacheConfig {
        merge.statsDir = scheme.statsDir ?? statsDir
        merge.downloadRetries = scheme.downloadRetries ?? downloadRetries
        merge.uploadRetries = scheme.uploadRetries ?? uploadRetries
+        merge.retryDelay = scheme.retryDelay ?? retryDelay
        merge.requestCustomHeaders = scheme.requestCustomHeaders ?? requestCustomHeaders
        merge.thinTargetMockFilename = scheme.thinTargetMockFilename ?? thinTargetMockFilename
        merge.focusedTargets = scheme.focusedTargets ?? focusedTargets
@@ -163,10 +191,17 @@ extension XCRemoteCacheConfig {
            scheme.productFilesExtensionsWithContentOverride ?? productFilesExtensionsWithContentOverride
        merge.thinningEnabled = scheme.thinningEnabled ?? thinningEnabled
        merge.thinningTargetModuleName = scheme.thinningTargetModuleName ?? thinningTargetModuleName
+        merge.prettifyMetaFiles = scheme.prettifyMetaFiles ?? prettifyMetaFiles
        merge.AWSAccessKey = scheme.AWSAccessKey ?? AWSAccessKey
        merge.AWSSecretKey = scheme.AWSSecretKey ?? AWSSecretKey
+        merge.AWSSecurityToken = scheme.AWSSecurityToken ?? AWSSecurityToken
        merge.AWSRegion = scheme.AWSRegion ?? AWSRegion
        merge.AWSService = scheme.AWSService ?? AWSService
+        merge.outOfBandMappings = scheme.outOfBandMappings ?? outOfBandMappings
+        merge.disableCertificateVerification = scheme.disableCertificateVerification ?? disableCertificateVerification
+        merge.disableVFSOverlay = scheme.disableVFSOverlay ?? disableVFSOverlay
+        merge.customRewriteEnvs = scheme.customRewriteEnvs ?? customRewriteEnvs
+        merge.irrelevantDependenciesPaths = scheme.irrelevantDependenciesPaths ?? irrelevantDependenciesPaths
        return merge
    }

@@ -211,6 +246,7 @@ struct ConfigFileScheme: Decodable {
    let statsDir: String?
    let downloadRetries: Int?
    let uploadRetries: Int?
+    let retryDelay: Double?
    let requestCustomHeaders: [String: String]?
    let thinTargetMockFilename: String?
    let focusedTargets: [String]?
@@ -221,10 +257,17 @@ struct ConfigFileScheme: Decodable {
    let productFilesExtensionsWithContentOverride: [String]?
    let thinningEnabled: Bool?
    let thinningTargetModuleName: String?
+    let prettifyMetaFiles: Bool?
    let AWSSecretKey: String?
    let AWSAccessKey: String?
+    let AWSSecurityToken: String?
    let AWSRegion: String?
    let AWSService: String?
+    let outOfBandMappings: [String: String]?
+    let disableCertificateVerification: Bool?
+    let disableVFSOverlay: Bool?
+    let customRewriteEnvs: [String]?
+    let irrelevantDependenciesPaths: [String]?

    // Yams library doesn't support encoding strategy, see https://github.com/jpsim/Yams/issues/84
    enum CodingKeys: String, CodingKey {
@@ -252,6 +295,7 @@ struct ConfigFileScheme: Decodable {
        case statsDir = "stats_dir"
        case downloadRetries = "download_retries"
        case uploadRetries = "upload_retries"
+        case retryDelay = "retry_delay"
        case requestCustomHeaders = "request_custom_headers"
        case thinTargetMockFilename = "thin_target_mock_filename"
        case focusedTargets = "focused_targets"
@@ -262,10 +306,17 @@ struct ConfigFileScheme: Decodable {
        case productFilesExtensionsWithContentOverride = "product_files_extensions_with_content_override"
        case thinningEnabled = "thinning_enabled"
        case thinningTargetModuleName = "thinning_target_module_name"
+        case prettifyMetaFiles = "prettify_meta_files"
        case AWSSecretKey = "aws_secret_key"
        case AWSAccessKey = "aws_access_key"
+        case AWSSecurityToken = "aws_security_token"
        case AWSRegion = "aws_region"
        case AWSService = "aws_service"
+        case outOfBandMappings = "out_of_band_mappings"
+        case disableCertificateVerification = "disable_certificate_verification"
+        case disableVFSOverlay = "disable_vfs_overlay"
+        case customRewriteEnvs = "custom_rewrite_envs"
+        case irrelevantDependenciesPaths = "irrelevant_dependencies_paths"
    }
 }

@@ -278,31 +329,42 @@ class XCRemoteCacheConfigReader {
    /// Name of the configuration file, required in $(SRCROOT) location
    private static let configurationFile = ".rcinfo"
    private let srcRoot: String
-    private let fileManager: FileManager
+    private let fileReader: FileReader
    private lazy var yamlDecorer = YAMLDecoder(encoding: .utf8)

-    init(env: [String: String], fileManager: FileManager) throws {
+    init(env: [String: String], fileReader: FileReader) throws {
        let explicitSrcRoot: String? = env.readEnv(key: "SRCROOT")
-        srcRoot = explicitSrcRoot ?? fileManager.currentDirectoryPath
-        self.fileManager = fileManager
+        srcRoot = explicitSrcRoot ?? FileManager.default.currentDirectoryPath
+        self.fileReader = fileReader
    }

-    init(srcRootPath srcRoot: String, fileManager: FileManager) {
+    init(srcRootPath srcRoot: String, fileReader: FileReader) {
        self.srcRoot = srcRoot
-        self.fileManager = fileManager
+        self.fileReader = fileReader
    }

+    // Reads the final configuration by loading all extra configs
+    // until reaching a config that doesn't override `extraConfigurationFile`
    func readConfiguration() throws -> XCRemoteCacheConfig {
        let rootURL = URL(fileURLWithPath: srcRoot)
        let configURL = URL(fileURLWithPath: Self.configurationFile, relativeTo: rootURL)
        let userConfigs = try readUserConfig(configURL)
        var config = XCRemoteCacheConfig(sourceRoot: srcRoot).merged(with: userConfigs)
-        let extraConfURL = URL(fileURLWithPath: config.extraConfigurationFile, relativeTo: rootURL)
-        do {
-            let extraConfig = try readUserConfig(extraConfURL)
-            config = config.merged(with: extraConfig)
-        } catch {
-            infoLog("Extra config override failed with \(error). Skipping extra configuration")
+        var extraConfURL = URL(fileURLWithPath: config.extraConfigurationFile, relativeTo: rootURL)
+        var visitedFiles = Set([configURL])
+        while !visitedFiles.contains(extraConfURL) {
+            do {
+                let extraConfig = try readUserConfig(extraConfURL)
+                debugLog("Reading extra configuration from \(extraConfURL)")
+                config = config.merged(with: extraConfig)
+                visitedFiles.insert(extraConfURL)
+                // Advance extra configuration
+                extraConfURL = URL(fileURLWithPath: config.extraConfigurationFile, relativeTo: rootURL)
+            } catch {
+                infoLog("Extra config override failed with \(error). Skipping extra configuration")
+                // swiftlint:disable:next unneeded_break_in_switch
+                break
+            }
        }

        return try config.verifyAndApplyDefaults()
@@ -310,7 +372,7 @@ class XCRemoteCacheConfigReader {

    /// Reads user configuration from a file
    private func readUserConfig(_ file: URL) throws -> ConfigFileScheme {
-        let configurationContent = fileManager.contents(atPath: file.path)
+        let configurationContent = try fileReader.contents(atPath: file.path)
        guard let configurationData = configurationContent else {
            throw XCRemoteCacheConfigReaderError.missingConfigurationFile(file)
        }
@@ -51,34 +51,22 @@ public class FileDependenciesReader: DependenciesReader {
    public func findDependencies() throws -> [String] {
        let yaml = try readRaw()

-        struct ParseState {
-            var buffer: String = ""
-            var prevChar: Character?
-            var result: [String] = []
-            func with(buffer: String? = nil, prevChar: Character? = nil, result: [String]? = nil) -> ParseState {
-                var new = self
-                new.buffer = buffer ?? new.buffer
-                new.prevChar = prevChar ?? new.prevChar
-                new.result = result ?? new.result
-                return new
-            }
-        }
-
        let dependencies = yaml.reduce(Set<String>()) { prev, arg1 -> Set<String> in
            let (key, value) = arg1
            switch key {
            case "dependencies":
                // 'clang' output formatting
-                return Set(splitDependencyFileList(value))
+                return Set(parseDependencyFileList(value))
            case let s where s.hasSuffix(".o") || s.hasSuffix(".bc"):
                // 'swiftc' output formatting
-                // take dependencies from any .o or .bc file.
+                // take dependencies from any .o or .bc file
                // Note: For WMO, all .{o|bc} files have the same dependencies
-                return Set(splitDependencyFileList(value))
+                return Set(parseDependencyFileList(value))
            default:
                return prev
            }
        }
+
        return Array(dependencies)
    }

@@ -92,56 +80,92 @@ public class FileDependenciesReader: DependenciesReader {
        return yaml.mapValues { $0.components(separatedBy: .whitespaces) }
    }

-    private func readRaw() throws -> [String: String] {
+    func readRaw() throws -> [String: String] {
+        let fileData = try getFileData()
+        let fileString = try getFileStringFromData(fileData: fileData)
+        let yaml = try getYaml(fileString: fileString)
+        return yaml
+    }
+
+    func getFileData() throws -> Data {
        guard let fileData = fileManager.contents(atPath: file.path) else {
            throw DependenciesReaderError.readingError
        }
+        return fileData
+    }
+
+    func getFileStringFromData(fileData: Data) throws -> String {
        guard let fileString = String(data: fileData, encoding: .utf8) else {
            throw DependenciesReaderError.invalidFile
        }
-        // .d matches the .yaml format
+        return fileString
+    }
+
+    func getYaml(fileString: String) throws -> [String: String] {
        guard let yaml = try Yams.load(yaml: fileString) as? [String: String] else {
            throw DependenciesReaderError.invalidFile
        }
        return yaml
    }

-    /// Splits space or new line separated files into a set of files
+    /// Parses the String to get the list of files
+    /// It iterates over the String using its UTF8View since it is more performant (String type operates
+    /// in a higher abstraction level and supports features that have a negative impact in the performance)
    /// It supports escaping whitespace charaters, prefixed with "\\"
    /// - Parameter string: string of whitespace charaters separated file paths
    /// - Returns: Array of all file paths
-    private func splitDependencyFileList(_ string: String) -> [String] {
-        struct ParseState {
-            var buffer: String = ""
-            var prevChar: Character?
-            var result: [String] = []
-            func with(buffer: String? = nil, prevChar: Character? = nil, result: [String]? = nil) -> ParseState {
-                var new = self
-                new.buffer = buffer ?? new.buffer
-                new.prevChar = prevChar ?? new.prevChar
-                new.result = result ?? new.result
-                return new
-            }
+    func parseDependencyFileList(_ string: String) -> [String] {
+        var result: [String] = []
+        var prevChar: UTF8.CodeUnit?
+
+        // These index are used to move over the UTF8View of the string
+        // The goal is to optimize the memory used, since UTF8View uses
+        // the same memory as the original String without copying it
+        var startIndex = string.utf8.startIndex
+        var endIndex = startIndex
+
+        // This buffer is only used to save the part of the path that has been already parsed when finding a backslash
+        var buffer: String = ""
+
+        for c in string.utf8 {
+          switch c {
+          case UTF8.CodeUnit(ascii: "\n") where prevChar == UTF8.CodeUnit(ascii: "\\"):
+              startIndex = string.utf8.index(after: startIndex)
+              endIndex = startIndex
+          case UTF8.CodeUnit(ascii: " ") where startIndex == endIndex && buffer.isEmpty:
+              startIndex = string.utf8.index(after: startIndex)
+              endIndex = startIndex
+          case UTF8.CodeUnit(ascii: " ") where prevChar != UTF8.CodeUnit(ascii: "\\"):
+              // If a space is found and it is not escaped, then that's the end of the file path
+              buffer += String(Substring(string.utf8[startIndex ..< endIndex]))
+              result.append(buffer)
+              buffer = ""
+              prevChar = nil
+              startIndex = string.utf8.index(after: endIndex)
+              endIndex = startIndex
+          case UTF8.CodeUnit(ascii: "\\"):
+              // If a backslash is found it is not included in the file path
+              // The current parsed range of the UTF8View is saved in the buffer as a String
+              buffer += String(Substring(string.utf8[startIndex ..< endIndex]))
+              // The backslash is assigned as the previous char
+              prevChar = c
+              // The indexes are moved to the next char so we continue parsing the String
+              startIndex = string.utf8.index(after: endIndex)
+              endIndex = startIndex
+          default:
+              // As long as it is possible the indexes are used to track the range of the string that
+              // will be included in the file path (until it ends or until a backslash is found)
+              endIndex = string.utf8.index(after: endIndex)
+              // The char is assigned as the previous char
+              prevChar = c
+          }
        }
-        let parseResult = string.reduce(ParseState()) { total, char in
-            switch char {
-            case "\n" where total.prevChar == "\\":
-                return total
-            case " " where total.buffer.isEmpty:
-                return total
-            case " " where total.prevChar == "\\":
-                return total.with(buffer: "\(total.buffer) ")
-            case " ":
-                return total.with(buffer: "", prevChar: nil, result: total.result + [total.buffer])
-            case "\\":
-                return total.with(prevChar: "\\")
-            default:
-                return total.with(buffer: "\(total.buffer)\(char)", prevChar: char, result: total.result)
-            }
+
+        if startIndex != endIndex {
+            buffer += String(Substring(string.utf8[startIndex ..< endIndex]))
+            result.append(buffer)
        }
-        if !parseResult.buffer.isEmpty {
-            return parseResult.result + [parseResult.buffer]
-        }
-        return parseResult.result
+
+        return result
    }
 }
@@ -22,9 +22,9 @@ import Foundation
 /// Replaces paths formats between generic (placeholders-based) and local
 protocol DependenciesRemapper {
    /// Replaces all generic paths (with placeholders) to a local paths
-    func replace(genericPaths: [String]) -> [String]
+    func replace(genericPaths: [String]) throws -> [String]
    /// Replaces all local paths to the generic dependencies paths
-    func replace(localPaths: [String]) -> [String]
+    func replace(localPaths: [String]) throws -> [String]
 }

 class DependenciesRemapperComposite: DependenciesRemapper {
@@ -34,15 +34,15 @@ class DependenciesRemapperComposite: DependenciesRemapper {
        self.remappers = remappers
    }

-    func replace(genericPaths: [String]) -> [String] {
-        remappers.reduce(genericPaths) { prev, mapper in
-            mapper.replace(genericPaths: prev)
+    func replace(genericPaths: [String]) throws -> [String] {
+        try remappers.reversed().reduce(genericPaths) { prev, mapper in
+            try mapper.replace(genericPaths: prev)
        }
    }

-    func replace(localPaths: [String]) -> [String] {
-        remappers.reduce(localPaths) { prev, mapper in
-            mapper.replace(localPaths: prev)
+    func replace(localPaths: [String]) throws -> [String] {
+        try remappers.reduce(localPaths) { prev, mapper in
+            try mapper.replace(localPaths: prev)
        }
    }
 }
@@ -59,16 +59,16 @@ final class StringDependenciesRemapper: DependenciesRemapper {
        self.mappings = mappings
    }

-    func replace(genericPaths: [String]) -> [String] {
+    func replace(genericPaths: [String]) throws -> [String] {
        return genericPaths.map { path in
-            let localPath = mappings.reduce(path) { prevPath, mapping in
+            let localPath = mappings.reversed().reduce(path) { prevPath, mapping in
                prevPath.replacingOccurrences(of: mapping.generic, with: mapping.local)
            }
            return localPath
        }
    }

-    func replace(localPaths: [String]) -> [String] {
+    func replace(localPaths: [String]) throws -> [String] {
        return localPaths.map { path in
            let result = mappings.reduce(path) { prevPath, mapping in
                prevPath.replacingOccurrences(of: mapping.local, with: mapping.generic)
@@ -77,14 +77,3 @@ final class StringDependenciesRemapper: DependenciesRemapper {
        }
    }
 }
-
-
-extension StringDependenciesRemapper {
-    static func buildFromEnvs(keys: [String], envs: [String: String]) throws -> Self {
-        let mappings: [Mapping] = try keys.map { key in
-            let localValue: String = try envs.readEnv(key: key)
-            return Mapping(generic: "$(\(key))", local: localValue)
-        }
-        return Self(mappings: mappings)
-    }
-}
@@ -50,7 +50,7 @@ public class FileDependenciesWriter: DependenciesWriter {
        var content = ""
        for (file, deps) in dependencies {
            content.append(file + ": ")
-            content.append(deps.joined(separator: " "))
+            content.append(deps.map { $0.replacingOccurrences(of: " ", with: "\\ ") }.joined(separator: " "))
            content.append("\n")
        }
        try content.write(to: file, atomically: true, encoding: .utf8)
@@ -27,8 +27,11 @@ public struct Dependency: Equatable {
        case source
        case fingerprint
        case intermediate
+        case derivedFile
        // Product of the target itself
        case ownProduct
+        // User-excluded path
+        case userExcluded
        case unknown
    }

@@ -55,14 +58,18 @@ class DependencyProcessorImpl: DependencyProcessor {
    private let productPath: String
    private let sourcePath: String
    private let intermediatePath: String
+    private let derivedFilesPath: String
    private let bundlePath: String?
+    private let skippedRegexes: [String]

-    init(xcode: URL, product: URL, source: URL, intermediate: URL, bundle: URL?) {
-        xcodePath = xcode.path
-        productPath = product.path
-        sourcePath = source.path
-        intermediatePath = intermediate.path
-        bundlePath = bundle?.path
+    init(xcode: URL, product: URL, source: URL, intermediate: URL, derivedFiles: URL, bundle: URL?, skippedRegexes: [String]) {
+        xcodePath = xcode.path.dirPath()
+        productPath = product.path.dirPath()
+        sourcePath = source.path.dirPath()
+        intermediatePath = intermediate.path.dirPath()
+        derivedFilesPath = derivedFiles.path.dirPath()
+        bundlePath = bundle?.path.dirPath()
+        self.skippedRegexes = skippedRegexes
    }

    func process(_ files: [URL]) -> [Dependency] {
@@ -72,11 +79,15 @@ class DependencyProcessorImpl: DependencyProcessor {

    private func classify(_ files: [URL]) -> [Dependency] {
        return files.map { file -> Dependency in
-            let filePath = file.path
-            if filePath.hasPrefix(xcodePath) {
+            let filePath = file.resolvingSymlinksInPath().path
+            if skippedRegexes.contains(where: { filePath.range(of: $0, options: .regularExpression) != nil }) {
+                return Dependency(url: file, type: .userExcluded)
+            } else if filePath.hasPrefix(xcodePath) {
                return Dependency(url: file, type: .xcode)
            } else if filePath.hasPrefix(intermediatePath) {
                return Dependency(url: file, type: .intermediate)
+            } else if filePath.hasPrefix(derivedFilesPath) {
+                return Dependency(url: file, type: .derivedFile)
            } else if let bundle = bundlePath, filePath.hasPrefix(bundle) {
                // If a target produces a bundle, explicitly classify all
                // of products to distinguish from other targets products
@@ -107,7 +118,18 @@ class DependencyProcessorImpl: DependencyProcessor {
        // - All files in `*/Interemediates/*` - this file are created on-fly for a given target
        // - Some files may depend on its own product (e.g. .m may #include *-Swift.h) - we know products will match
        //   because in case of a hit, these will be taken from the artifact
-        let irrelevantDependenciesType: [Dependency.Kind] = [.xcode, .intermediate, .ownProduct]
+        // - Customized DERIVED_FILE_DIR may change a directory of
+        //   derived files, which by default is under `*/Interemediates`
+        // - User-specified (in .rcinfo) files to exclude
+        let irrelevantDependenciesType: [Dependency.Kind] = [
+            .xcode, .intermediate, .ownProduct, .derivedFile, .userExcluded,
+        ]
        return !irrelevantDependenciesType.contains(dependency.type)
    }
 }
+
+fileprivate extension String {
+    func dirPath() -> String {
+        hasSuffix("/") ? self : appending("/")
+    }
+}
@@ -0,0 +1,67 @@
+// Copyright (c) 2021 Spotify AB.
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+import Foundation
+
+/// File paths remapper according the virtual file system mappings
+/// - Warning: this class is not thread safe
+class OverlayDependenciesRemapper: DependenciesRemapper {
+    private let overlayReader: OverlayReader
+    private var mappings: [OverlayMapping]?
+
+    init(overlayReader: OverlayReader) {
+        self.overlayReader = overlayReader
+    }
+
+    /// Lazily Reads mappings from a file
+    /// - Warning: this function is not thread safe
+    private func getMappings() throws -> [OverlayMapping] {
+        guard let mappings = mappings else {
+            let mappings = try overlayReader.provideMappings()
+            self.mappings = mappings
+            return mappings
+        }
+        return mappings
+    }
+
+    private func mapPath(
+        _ path: String,
+        source: KeyPath<OverlayMapping, URL>,
+        destination: KeyPath<OverlayMapping, URL>
+    ) throws -> String {
+        guard let mapping = try getMappings().first(where: { $0[keyPath: source].path == path }) else {
+            // TODO: support partial mappings, where a directory path can be replaced with some other directory
+            // no direct mapping found
+            return path
+        }
+        return mapping[keyPath: destination].path
+    }
+
+    func replace(genericPaths: [String]) throws -> [String] {
+        try genericPaths.map {
+            try mapPath($0, source: \.virtual, destination: \.local)
+        }
+    }
+
+    func replace(localPaths: [String]) throws -> [String] {
+        try localPaths.map {
+            try mapPath($0, source: \.local, destination: \.virtual)
+        }
+    }
+}
@@ -0,0 +1,133 @@
+// Copyright (c) 2021 Spotify AB.
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+import Foundation
+
+/// Maps overlay's virtual URL with an actual (local) location
+struct OverlayMapping: Hashable {
+    let virtual: URL
+    let local: URL
+}
+
+enum JsonOverlayReaderError: Error {
+    /// The source file is missing
+    case missingSourceFile(URL)
+    /// The file exists but its content is invalid
+    case invalidSourceContent(URL)
+    /// the overlay format is not supported - either contains a nested directory or a single file 
+    case unsupportedFormat
+}
+/// Provides virtual file system overlay mappings
+protocol OverlayReader {
+    func provideMappings() throws -> [OverlayMapping]
+}
+
+class JsonOverlayReader: OverlayReader {
+
+    enum Mode {
+        /// Interrupts the operation if the representation file is missing
+        case strict
+        /// Assume empty overlay mapping if the file doesn't exist
+        case bestEffort
+    }
+
+    private struct Overlay: Decodable {
+        enum OverlayType: String, Decodable {
+            case file
+            case directory
+        }
+
+        struct Content: Decodable {
+            let externalContents: String
+            let name: String
+            let type: OverlayType
+
+            enum CodingKeys: String, CodingKey {
+                case externalContents = "external-contents"
+                case name
+                case type
+            }
+        }
+
+        struct RootContent: Decodable {
+            let contents: [Content]
+            let name: String
+            let type: OverlayType
+        }
+        let roots: [RootContent]
+    }
+
+    private lazy var jsonDecoder = JSONDecoder()
+    private let json: URL
+    private let mode: Mode
+    private let fileReader: FileReader
+
+
+    init(_ json: URL, mode: Mode, fileReader: FileReader) {
+        self.json = json
+        self.mode = mode
+        self.fileReader = fileReader
+    }
+
+    func provideMappings() throws -> [OverlayMapping] {
+        guard let jsonContent = try fileReader.contents(atPath: json.path) else {
+            switch mode {
+            case .strict:
+                throw JsonOverlayReaderError.missingSourceFile(json)
+            case .bestEffort:
+                debugLog("overlay mapping file \(json) doesn't exist. Skipping overlay for the best-effort mode.")
+                return []
+            }
+        }
+        do {
+        let overlay: Overlay = try jsonDecoder.decode(Overlay.self, from: jsonContent)
+            let mappings: [OverlayMapping] = try overlay.roots.reduce([]) { prev, root in
+                switch root.type {
+                case .directory:
+                    // iterate all contents
+                    let dir = URL(fileURLWithPath: root.name)
+                    let mappings: [OverlayMapping] = try root.contents.map { content in
+                        switch content.type {
+                        case .file:
+                            let virtual = dir.appendingPathComponent(content.name)
+                            let local = URL(fileURLWithPath: content.externalContents)
+                            return .init(virtual: virtual, local: local)
+                        case .directory:
+                            throw JsonOverlayReaderError.unsupportedFormat
+                        }
+
+                    }
+                    return prev + mappings
+                case .file:
+                    throw JsonOverlayReaderError.unsupportedFormat
+                }
+            }
+            return mappings
+        } catch {
+            switch mode {
+            case .strict:
+                throw error
+            case .bestEffort:
+                errorLog("Overlay reader has failed with an error \(error). Best-effort mode - skipping an overlay.")
+                return []
+            }
+        }
+    }
+
+}
@@ -0,0 +1,47 @@
+// Copyright (c) 2021 Spotify AB.
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+import Foundation
+
+enum PathDependenciesRemapperFactoryError: Error {
+    /// Remapping keys are duplicated and can lead to undetermined results
+    case mappingKeyDuplication
+}
+
+class PathDependenciesRemapperFactory {
+    func build(
+        orderKeys: [String],
+        envs: [String: String],
+        customMappings: [String: String]
+    ) throws -> StringDependenciesRemapper {
+        let mappingMap = try envs.merging(customMappings) { _, _ in
+            throw PathDependenciesRemapperFactoryError.mappingKeyDuplication
+        }
+        let mappingOrderKeys = orderKeys + customMappings.keys
+        let mappings: [StringDependenciesRemapper.Mapping] = mappingOrderKeys.compactMap { key in
+            guard let localURL: URL = mappingMap.readEnv(key: key) else {
+                debugLog("\(key) ENV to map a dependency is not defined")
+                return nil
+            }
+            infoLog("Found url to remapp: \(localURL). Remapping: \(localURL.standardized.path)")
+            return StringDependenciesRemapper.Mapping(generic: "$(\(key))", local: localURL.standardized.path)
+        }
+        return StringDependenciesRemapper(mappings: mappings)
+    }
+}
@@ -42,7 +42,7 @@ class TargetDependenciesReader: DependenciesReader {
        let allURLs = try dirScanner.items(at: directory)
        let mergedDependencies = try allURLs.reduce(Set<String>()) { (prev: Set<String>, file) in
            // include only these .d files that either have corresponding .o file (incremental) or end
-            // with '-master' (whole-module).
+            // with '-master' (whole-module)
            // Otherwise .d is probably just a leftover from previous builds
            let correspondingOutputURL = file.deletingPathExtension().appendingPathExtension("o")
            let isDependencyFile = file.pathExtension == "d"
@@ -19,10 +19,10 @@

 /// Generates a fingerprint string of the environment (compilation context)
 class EnvironmentFingerprintGenerator {
-    /// Default ENV variables constituing the environment fingerprint
+    /// Default ENV variables constituting the environment fingerprint
    private static let defaultEnvFingerprintKeys = [
        "GCC_PREPROCESSOR_DEFINITIONS",
-        "CLANG_PROFILE_DATA_DIRECTORY",
+        "CLANG_COVERAGE_MAPPING",
        "TARGET_NAME",
        "CONFIGURATION",
        "PLATFORM_NAME",
@@ -31,6 +31,7 @@ class EnvironmentFingerprintGenerator {
        "DYLIB_COMPATIBILITY_VERSION",
        "DYLIB_CURRENT_VERSION",
        "PRODUCT_MODULE_NAME",
+        "ARCHS",
    ]
    private let version: String
    private let customFingerprintEnvs: [String]
@@ -51,7 +52,9 @@ class EnvironmentFingerprintGenerator {
        }
        try fill(envKeys: Self.defaultEnvFingerprintKeys + customFingerprintEnvs)
        try generator.append(version)
-        return try generator.generate()
+        let result = try generator.generate()
+        generatedFingerprint = result
+        return result
    }

    /// Creates a fingerprint of the environemtn, by hashing all ENVs specified in keys
@@ -22,34 +22,36 @@ import Foundation
 import os.log


+private var processTag: String = ""
+
 public func exit(_ exitCode: Int32, _ message: String) -> Never {
-    os_log("%{public}@", log: OSLog.default, type: .error, message)
+    os_log("%{public}@%{public}@", log: OSLog.default, type: .error, processTag, message)
    printError(errorMessage: message)
    exit(exitCode)
 }

 func defaultLog(_ message: String) {
-    os_log("%{public}@", log: OSLog.default, type: .default, message)
+    os_log("%{public}@%{public}@", log: OSLog.default, type: .default, processTag, message)
 }

 func errorLog(_ message: String) {
-    os_log("%{public}@", log: OSLog.default, type: .error, message)
+    os_log("%{public}@%{public}@", log: OSLog.default, type: .error, processTag, message)
 }

 func infoLog(_ message: String) {
-    os_log("%{public}@", log: OSLog.default, type: .info, message)
+    os_log("%{public}@%{public}@", log: OSLog.default, type: .info, processTag, message)
 }

 func debugLog(_ message: String) {
-    os_log("%{public}@", log: OSLog.default, type: .debug, message)
+    os_log("%{public}@%{public}@", log: OSLog.default, type: .debug, processTag, message)
 }

 func printError(errorMessage: String) {
-    fputs("error: \(errorMessage)\n", stderr)
+    fputs("error: \(processTag)\(errorMessage)\n", stderr)
 }

 func printWarning(_ message: String) {
-    print("warning: \(message)")
+    print("warning: \(processTag)\(message)")
 }

 /// Prints a message to the user. It shows in Xcode (if applies) or console output
@@ -57,3 +59,7 @@ func printWarning(_ message: String) {
 func printToUser(_ message: String) {
    print("[RC] \(message)")
 }
+
+func updateProcessTag(_ tag: String) {
+    processTag = "(\(tag)) "
+}
@@ -0,0 +1,45 @@
+// Copyright (c) 2021 Spotify AB.
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+import Foundation
+
+protocol MetaWriter {
+    func write<T>(_ meta: T, locationDir: URL) throws -> URL where T: Meta
+}
+
+class JsonMetaWriter: MetaWriter {
+    private let metaEncoder: JSONEncoder
+    private let fileWriter: FileWriter
+
+    init(fileWriter: FileWriter, pretty: Bool) {
+        self.fileWriter = fileWriter
+        let encoder = JSONEncoder()
+        if pretty {
+            encoder.outputFormatting = .prettyPrinted
+        }
+        self.metaEncoder = encoder
+    }
+
+    func write<T>(_ meta: T, locationDir: URL) throws -> URL where T: Meta {
+        let metaURL = locationDir.appendingPathComponent(meta.fileKey).appendingPathExtension("json")
+        let metaData = try metaEncoder.encode(meta)
+        try fileWriter.write(toPath: metaURL.path, contents: metaData)
+        return metaURL
+    }
+}
@@ -23,21 +23,38 @@ struct AWSV4Signature {

    let secretKey: String
    let accessKey: String
+    let securityToken: String?
    let region: String
    let service: String
    let date: Date

-
    func addSignatureHeaderTo(request: inout URLRequest) {

        request.setValue(request.url?.host, forHTTPHeaderField: "host")
        request.setValue(StringToSign.ISO8601BasicFormatter.string(from: date), forHTTPHeaderField: "x-amz-date")
        request.setValue((request.httpBody ?? Data()).sha256(), forHTTPHeaderField: "x-amz-content-sha256")

+        if let securityToken = securityToken {
+            request.setValue(securityToken, forHTTPHeaderField: "x-amz-security-token")
+        }
+
        let canonicalRequest = CanonicalRequest(request: request)
-        let stringToSign = StringToSign(region: region, service: service, canonicalRequestHash: canonicalRequest.hash, date: date)
-        let awsV4SigningKey = AWSV4SigningKey(secretAccessKey: secretKey, region: region, service: service, date: date)
-        let signature = HMAC.calcHMAC(keyArray: awsV4SigningKey.value, value: stringToSign.value).map { String(format: "%02hhx", $0) }.joined()
+        let stringToSign = StringToSign(
+            region: region,
+            service: service,
+            canonicalRequestHash: canonicalRequest.hash,
+            date: date
+        )
+        let awsV4SigningKey = AWSV4SigningKey(
+            secretAccessKey: secretKey,
+            region: region,
+            service: service,
+            date: date
+        )
+        let signature = HMAC.calcHMAC(
+            keyArray: awsV4SigningKey.value,
+            value: stringToSign.value
+        ).map { String(format: "%02hhx", $0) }.joined()

        let authValue =
            "AWS4-HMAC-SHA256 " +
@@ -52,7 +52,14 @@ struct HMAC {

    private static func calcHMAC(keyUnsafeBytes: UnsafeRawBufferPointer, value: String, out: UnsafeMutableRawPointer!) {
        value.data(using: .utf8)!.withUnsafeBytes { value in
-            CCHmac(CCHmacAlgorithm(kCCHmacAlgSHA256), keyUnsafeBytes.baseAddress, Int(keyUnsafeBytes.count), value.baseAddress, Int(value.count), out)
+            CCHmac(
+                CCHmacAlgorithm(kCCHmacAlgSHA256),
+                keyUnsafeBytes.baseAddress,
+                Int(keyUnsafeBytes.count),
+                value.baseAddress,
+                Int(value.count),
+                out
+            )
        }
    }
 }
@@ -0,0 +1,32 @@
+// Copyright (c) 2021 Spotify AB.
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+import Foundation
+
+final class IgnoringCertificatesTrustManager: NSObject, URLSessionDelegate {
+    func urlSession(_ session: URLSession, didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) {
+        guard let serverTrust = challenge.protectionSpace.serverTrust else {
+            completionHandler(.performDefaultHandling, nil)
+            return
+        }
+
+        let urlCredential = URLCredential(trust: serverTrust)
+        completionHandler(.useCredential, urlCredential)
+    }
+}
@@ -29,12 +29,14 @@ class NetworkClientImpl: NetworkClient {
    private let session: URLSession
    private let fileManager: FileManager
    private let maxRetries: Int
+    private let retryDelay: TimeInterval
    private let awsV4Signature: AWSV4Signature?

-    init(session: URLSession, retries: Int, fileManager: FileManager, awsV4Signature: AWSV4Signature?) {
+    init(session: URLSession, retries: Int, retryDelay: TimeInterval, fileManager: FileManager, awsV4Signature: AWSV4Signature?) {
        self.session = session
        self.fileManager = fileManager
-        maxRetries = retries
+        self.maxRetries = retries
+        self.retryDelay = retryDelay
        self.awsV4Signature = awsV4Signature
    }

@@ -173,7 +175,13 @@ class NetworkClientImpl: NetworkClient {
            if let error = responseError {
                if retries > 0 {
                    infoLog("Upload request failed with \(error). Left retries: \(retries).")
-                    self.makeUploadRequest(request, input: input, retries: retries - 1, completion: completion)
+                    self.retryUpload(
+                        request,
+                        input: input,
+                        retries: retries,
+                        completion: completion,
+                        after: self.retryDelay
+                    )
                    return
                }
                errorLog("Upload request failed: \(error)")
@@ -184,6 +192,13 @@ class NetworkClientImpl: NetworkClient {
        }
        dataTask.resume()
    }
+
+    private func retryUpload(_ request: URLRequest, input: URL, retries: Int, completion: @escaping (Result<Void, NetworkClientError>) -> Void, after: TimeInterval) {
+        DispatchQueue.global().asyncAfter(deadline: .now() + after) { [weak self] in
+            guard let self = self else { return }
+            self.makeUploadRequest(request, input: input, retries: retries - 1, completion: completion)
+        }
+    }
 }

 private extension NetworkClientError {
@@ -44,7 +44,7 @@ class RemoteNetworkClientAbstractFactory {
            return RemoteNetworkClientImpl(networkClient, downloadURLBuilder)
        }
        switch mode {
-        case .producer:
+        case .producer, .producerFast:
            let upstreamBuilders = try upstreamStreamURL.map(urlBuilderFactory)
            return ReplicatedRemotesNetworkClient(
                networkClient,
@@ -36,6 +36,17 @@ class DefaultURLSessionFactory: URLSessionFactory {
        let configuration = URLSessionConfiguration.default
        configuration.httpAdditionalHeaders = config.requestCustomHeaders
        configuration.timeoutIntervalForRequest = config.timeoutResponseDataChunksInterval
-        return URLSession(configuration: configuration)
+        configuration.urlCache?.memoryCapacity = 0
+        configuration.urlCache?.diskCapacity = 0
+        switch config.disableCertificateVerification {
+        case true:
+            return URLSession(
+                configuration: configuration,
+                delegate: IgnoringCertificatesTrustManager(),
+                delegateQueue: nil
+            )
+        case false:
+            return URLSession(configuration: configuration)
+        }
    }
 }
@@ -28,8 +28,8 @@ protocol CacheHitLogger {
 /// Logs target hit or miss, based on an action of a build
 class ActionSpecificCacheHitLogger: CacheHitLogger {
    private let statsLogger: StatsLogger
-    private let hitCounter: XCRemoteCacheStatistics.Counter
-    private let missCounter: XCRemoteCacheStatistics.Counter
+    private let hitCounter: XCRemoteCacheStatistics.Counter?
+    private let missCounter: XCRemoteCacheStatistics.Counter?

    init(action: BuildActionType, statsLogger: StatsLogger) {
        self.statsLogger = statsLogger
@@ -37,19 +37,24 @@ class ActionSpecificCacheHitLogger: CacheHitLogger {
        case .index:
            hitCounter = .indexingTargetHitCount
            missCounter = .indexingTargetMissCount
-        case .unknown:
-            fallthrough
        case .build:
            hitCounter = .targetCacheHit
            missCounter = .targetCacheMiss
+        case .unknown:
+            hitCounter = nil
+            missCounter = nil
        }
    }

    func logHit() throws {
-        try statsLogger.log(hitCounter)
+        if let hitCounter = hitCounter {
+            try statsLogger.log(hitCounter)
+        }
    }

    func logMiss() throws {
-        try statsLogger.log(missCounter)
+        if let missCounter = missCounter {
+            try statsLogger.log(missCounter)
+        }
    }
 }
@@ -76,8 +76,8 @@ class ExclusiveFile: ExclusiveFileAccessor {
        guard flock(fd, LOCK_EX) == 0 else {
            throw FileAccessorError.lockingFailure
        }
-        // While having a lock, make sure the file still exists.
-        // It might delete it while we were waiting for a lock.
+        // While having a lock, make sure the file still exists
+        // It might delete it while we were waiting for a lock
        guard access(fileURL.path, F_OK) == 0 else {
            throw FileAccessorError.lockingFailure
        }
@@ -24,8 +24,15 @@ enum EnvironmentError: Error {
 }

 extension Dictionary where Key == String, Value == String {
-    func readEnv(key: String) throws -> URL {
+    func readEnv(key: String) -> URL? {
        guard let value = self[key].map(URL.init(fileURLWithPath:)) else {
+            return nil
+        }
+        return value
+    }
+
+    func readEnv(key: String) throws -> URL {
+        guard let value: URL = readEnv(key: key) else {
            throw EnvironmentError.missingEnv(key)
        }
        return value
@@ -21,7 +21,7 @@ import Foundation
 import XCRemoteCache

 /// Wrapper for a `LD` program that copies the dynamic executable from a cached-downloaded location
-/// Fallbacks to a standard `clang` when the Ramote cache is not applicable (e.g. modified sources)
+/// Fallbacks to a standard `clang` when the Remote cache is not applicable (e.g. modified sources)
 public class XCLDMain {
    public func main() {
        let args = ProcessInfo().arguments
@@ -48,7 +48,16 @@ public class XCLDMain {
            i += 1
        }
        guard let outputInput = output, let filelistInput = filelist, let dependencyInfoInput = dependencyInfo else {
-            exit(1, "Missing 'output' argument. Args: \(args)")
+            let ldCommand = "clang"
+            print("Fallbacking to compilation using \(ldCommand).")
+
+            let args = ProcessInfo().arguments
+            let paramList = [ldCommand] + args.dropFirst()
+            let cargs = paramList.map { strdup($0) } + [nil]
+            execvp(ldCommand, cargs)
+
+            /// C-function `execv` returns only when the command fails
+            exit(1)
        }


@@ -0,0 +1,75 @@
+// Copyright (c) 2021 Spotify AB.
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+import Foundation
+import XCRemoteCache
+
+/// Wrapper for a `LDPLUSPLUS` program that copies the dynamic executable from a cached-downloaded location
+/// Fallbacks to a standard `clang++` when the Remote cache is not applicable (e.g. modified sources)
+public class XCLDPlusPlusMain {
+    public func main() {
+        let args = ProcessInfo().arguments
+        var output: String?
+        var filelist: String?
+        var dependencyInfo: String?
+        var i = 0
+        while i < args.count {
+            switch args[i] {
+            case "-o":
+                output = args[i + 1]
+                i += 1
+            case "-filelist":
+                filelist = args[i + 1]
+                i += 1
+            case "-dependency_info":
+                // Skip following `-Xlinker` argument. Sample call:
+                // `clang -dynamiclib  ... -Xlinker -dependency_info -Xlinker /path/Target_dependency_info.dat`
+                dependencyInfo = args[i + 2]
+                i += 2
+            default:
+                break
+            }
+            i += 1
+        }
+        guard let outputInput = output, let filelistInput = filelist, let dependencyInfoInput = dependencyInfo else {
+            let ldCommand = "clang++"
+            print("Fallbacking to compilation using \(ldCommand).")
+
+            let args = ProcessInfo().arguments
+            let paramList = [ldCommand] + args.dropFirst()
+            let cargs = paramList.map { strdup($0) } + [nil]
+            execvp(ldCommand, cargs)
+
+            /// C-function `execv` returns only when the command fails
+            exit(1)
+        }
+
+
+        // TODO: consider using `clang_command` from .rcinfo
+        /// concrete clang path should be taken from the current toolchain
+        let fallbackCommand = "clang++"
+        XCCreateBinary(
+            output: outputInput,
+            filelist: filelistInput,
+            dependencyInfo: dependencyInfoInput,
+            fallbackCommand: fallbackCommand,
+            stepDescription: "xcldplusplus"
+        ).run()
+    }
+}
@@ -0,0 +1,22 @@
+// Copyright (c) 2021 Spotify AB.
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+import XCRemoteCache
+
+XCLDPlusPlusMain().main()
@@ -60,8 +60,16 @@ public class XCSwiftcMain {
            let targetInputInput = target,
            let swiftFileListInput = swiftFileList
            else {
-                print("Missing argument. Args: \(args)")
-                exit(1)
+            let swiftcCommand = "swiftc"
+            print("Fallbacking to compilation using \(swiftcCommand).")
+
+            let args = ProcessInfo().arguments
+            let paramList = [swiftcCommand] + args.dropFirst()
+            let cargs = paramList.map { strdup($0) } + [nil]
+            execvp(swiftcCommand, cargs)
+
+            /// C-function `execv` returns only when the command fails
+            exit(1)
        }
        let swiftcArgsInput = SwiftcArgInput(
            objcHeaderOutput: objcHeaderOutputInput,
@@ -27,15 +27,18 @@ class ArtifactSwiftProductsBuilderImplTests: FileXCTestCase {
    private var swiftmoduleFile: URL!
    private var swiftmoduleDocFile: URL!
    private var swiftmoduleSourceInfoFile: URL!
+    private var swiftmoduleInterfaceFile: URL!
    private var workingDir: URL!
    private var builder: ArtifactSwiftProductsBuilderImpl!

    override func setUpWithError() throws {
+        try super.setUpWithError()
        let rootDir = try prepareTempDir()
        moduleDir = rootDir.appendingPathComponent("Products")
        swiftmoduleFile = moduleDir.appendingPathComponent("MyModule.swiftmodule")
        swiftmoduleDocFile = moduleDir.appendingPathComponent("MyModule.swiftdoc")
        swiftmoduleSourceInfoFile = moduleDir.appendingPathComponent("MyModule.swiftsourceinfo")
+        swiftmoduleInterfaceFile = moduleDir.appendingPathComponent("MyModule.swiftinterface")
        workingDir = rootDir.appendingPathComponent("working")
        builder = ArtifactSwiftProductsBuilderImpl(
            workingDir: workingDir,
@@ -47,24 +50,41 @@ class ArtifactSwiftProductsBuilderImplTests: FileXCTestCase {
    func testIncludesRequiredSwiftmoduleFiles() throws {
        try fileManager.spt_createFile(swiftmoduleFile, content: "swiftmodule")
        try fileManager.spt_createFile(swiftmoduleDocFile, content: "swiftdoc")
-        let builderSwiftmoduleDir = builder.buildingArtifactSwiftModulesLocation().appendingPathComponent("arm64")
-        let expectedBuildedSwiftmoduleFile = builderSwiftmoduleDir.appendingPathComponent("MyModule.swiftmodule")
-        let expectedBuildedSwiftmoduledocFile = builderSwiftmoduleDir.appendingPathComponent("MyModule.swiftdoc")
+        let builderSwiftmoduleDir =
+            builder
+                .buildingArtifactSwiftModulesLocation()
+                .appendingPathComponent("arm64")
+        let expectedBuildedSwiftmoduleFile =
+            builderSwiftmoduleDir.appendingPathComponent("MyModule.swiftmodule")
+        let expectedBuildedSwiftmoduledocFile =
+            builderSwiftmoduleDir.appendingPathComponent("MyModule.swiftdoc")

        try builder.includeModuleDefinitionsToTheArtifact(arch: "arm64", moduleURL: swiftmoduleFile)

-        XCTAssertEqual(fileManager.contents(atPath: expectedBuildedSwiftmoduleFile.path), "swiftmodule".data(using: .utf8))
-        XCTAssertEqual(fileManager.contents(atPath: expectedBuildedSwiftmoduledocFile.path), "swiftdoc".data(using: .utf8))
+        XCTAssertEqual(
+            fileManager.contents(atPath: expectedBuildedSwiftmoduleFile.path),
+            "swiftmodule".data(using: .utf8)
+        )
+        XCTAssertEqual(
+            fileManager.contents(atPath: expectedBuildedSwiftmoduledocFile.path),
+            "swiftdoc".data(using: .utf8)
+        )
    }

-    func testIncludesAllSwiftmoduleFiles() throws {
+    func testIncludesAllBasicSwiftmoduleFiles() throws {
        try fileManager.spt_createEmptyFile(swiftmoduleFile)
        try fileManager.spt_createEmptyFile(swiftmoduleDocFile)
        try fileManager.spt_createEmptyFile(swiftmoduleSourceInfoFile)
-        let builderSwiftmoduleDir = builder.buildingArtifactSwiftModulesLocation().appendingPathComponent("arm64")
-        let expectedBuildedSwiftmoduleFile = builderSwiftmoduleDir.appendingPathComponent("MyModule.swiftmodule")
-        let expectedBuildedSwiftmoduledocFile = builderSwiftmoduleDir.appendingPathComponent("MyModule.swiftdoc")
-        let expectedBuildedSwiftSourceInfoFile = builderSwiftmoduleDir.appendingPathComponent("MyModule.swiftsourceinfo")
+        let builderSwiftmoduleDir =
+            builder
+                .buildingArtifactSwiftModulesLocation()
+                .appendingPathComponent("arm64")
+        let expectedBuildedSwiftmoduleFile =
+            builderSwiftmoduleDir.appendingPathComponent("MyModule.swiftmodule")
+        let expectedBuildedSwiftmoduledocFile =
+            builderSwiftmoduleDir.appendingPathComponent("MyModule.swiftdoc")
+        let expectedBuildedSwiftSourceInfoFile =
+            builderSwiftmoduleDir.appendingPathComponent("MyModule.swiftsourceinfo")

        try builder.includeModuleDefinitionsToTheArtifact(arch: "arm64", moduleURL: swiftmoduleFile)

@@ -73,7 +93,38 @@ class ArtifactSwiftProductsBuilderImplTests: FileXCTestCase {
        XCTAssertTrue(fileManager.fileExists(atPath: expectedBuildedSwiftSourceInfoFile.path))
    }

+    func testIncludesAllEvolutionEnabledSwiftmoduleFiles() throws {
+        try fileManager.spt_createEmptyFile(swiftmoduleFile)
+        try fileManager.spt_createEmptyFile(swiftmoduleDocFile)
+        try fileManager.spt_createEmptyFile(swiftmoduleSourceInfoFile)
+        try fileManager.spt_createEmptyFile(swiftmoduleInterfaceFile)
+        let builderSwiftmoduleDir =
+            builder
+                .buildingArtifactSwiftModulesLocation()
+                .appendingPathComponent("arm64")
+        let expectedBuildedSwiftmoduleFile =
+            builderSwiftmoduleDir.appendingPathComponent("MyModule.swiftmodule")
+        let expectedBuildedSwiftmoduledocFile =
+            builderSwiftmoduleDir.appendingPathComponent("MyModule.swiftdoc")
+        let expectedBuildedSwiftSourceInfoFile =
+            builderSwiftmoduleDir.appendingPathComponent("MyModule.swiftsourceinfo")
+        let expectedBuildedSwiftInterfaceFile =
+            builderSwiftmoduleDir.appendingPathComponent("MyModule.swiftinterface")
+
+        try builder.includeModuleDefinitionsToTheArtifact(arch: "arm64", moduleURL: swiftmoduleFile)
+
+        XCTAssertTrue(fileManager.fileExists(atPath: expectedBuildedSwiftmoduleFile.path))
+        XCTAssertTrue(fileManager.fileExists(atPath: expectedBuildedSwiftmoduledocFile.path))
+        XCTAssertTrue(fileManager.fileExists(atPath: expectedBuildedSwiftSourceInfoFile.path))
+        XCTAssertTrue(fileManager.fileExists(atPath: expectedBuildedSwiftInterfaceFile.path))
+    }
+
    func testFailsIncludingWhenMissingRequiredSwiftmoduleFiles() throws {
-        XCTAssertThrowsError(try builder.includeModuleDefinitionsToTheArtifact(arch: "arm64", moduleURL: swiftmoduleFile))
+        XCTAssertThrowsError(
+            try builder.includeModuleDefinitionsToTheArtifact(
+                arch: "arm64",
+                moduleURL: swiftmoduleFile
+            )
+        )
    }
 }
@@ -31,6 +31,7 @@ class BuildArtifactCreatorTests: FileXCTestCase {
    private var swiftmoduleURL: URL!
    private var swiftdocURL: URL!
    private var swiftSourceInfoURL: URL!
+    private var swiftInterfaceURL: URL!
    private var executablePath: String!
    private var executableURL: URL!
    private var creator: BuildArtifactCreator!
@@ -50,6 +51,8 @@ class BuildArtifactCreatorTests: FileXCTestCase {
            .appendingPathComponent("Target.swiftdoc")
        swiftSourceInfoURL = workDirectory.appendingPathComponent("Objects-normal")
            .appendingPathComponent("Target.swiftsourceinfo")
+        swiftInterfaceURL = workDirectory.appendingPathComponent("Objects-normal")
+            .appendingPathComponent("Target.swiftinterface")
        executablePath = "libTarget.a"
        executableURL = buildDir.appendingPathComponent(executablePath)
        dSYM = executableURL.deletingPathExtension().appendingPathExtension(".dSYM")
@@ -63,6 +66,7 @@ class BuildArtifactCreatorTests: FileXCTestCase {
            moduleName: "Target",
            modulesFolderPath: "",
            dSYMPath: dSYM,
+            metaWriter: JsonMetaWriter(fileWriter: fileManager, pretty: false),
            fileManager: fileManager
        )
    }
@@ -113,6 +117,28 @@ class BuildArtifactCreatorTests: FileXCTestCase {
        ])
    }

+    func testPackagesEvolutionEnabledSwiftmoduleFiles() throws {
+        try fileManager.spt_createEmptyFile(swiftmoduleURL)
+        try fileManager.spt_createEmptyFile(swiftdocURL)
+        try fileManager.spt_createEmptyFile(swiftSourceInfoURL)
+        try fileManager.spt_createEmptyFile(swiftInterfaceURL)
+
+        try creator.includeModuleDefinitionsToTheArtifact(arch: "arch", moduleURL: swiftmoduleURL)
+        let artifact = try creator.createArtifact(artifactKey: "key", meta: sampleMeta)
+
+        let unzippedURL = workDirectory.appendingPathComponent(UUID().uuidString)
+        try Zip.unzipFile(artifact.package, destination: unzippedURL, overwrite: true, password: nil, progress: nil)
+        let allFiles = try fileManager.spt_allFilesRecusively(unzippedURL)
+        XCTAssertEqual(Set(allFiles), [
+            unzippedURL.appendingPathComponent("libTarget.a"),
+            unzippedURL.appendingPathComponent("fileKey.json"),
+            unzippedURL.appendingPathComponent("swiftmodule/arch/Target.swiftmodule"),
+            unzippedURL.appendingPathComponent("swiftmodule/arch/Target.swiftdoc"),
+            unzippedURL.appendingPathComponent("swiftmodule/arch/Target.swiftsourceinfo"),
+            unzippedURL.appendingPathComponent("swiftmodule/arch/Target.swiftinterface"),
+        ])
+    }
+
    func testFailsPackageWhenSwiftmoduleRelatedFilesAreMissing() throws {
        // Creating only `Target.swiftmodule`, without `.swiftdoc`
        try fileManager.spt_createEmptyFile(swiftmoduleURL)
@@ -35,7 +35,11 @@ class ZipArtifactCreatorTests: FileXCTestCase {
    override func setUpWithError() throws {
        try super.setUpWithError()
        workingDir = try prepareTempDir().appendingPathComponent("creator")
-        creator = ZipArtifactCreator(workingDir: workingDir, fileManager: fileManager)
+        creator = ZipArtifactCreator(
+            workingDir: workingDir,
+            metaWriter: JsonMetaWriter(fileWriter: fileManager, pretty: false),
+            fileManager: fileManager
+        )
    }

    func testCreatingArtifactGeneratesValidArtifactId() throws {
@@ -33,7 +33,10 @@ class ThinningCreatorPluginTests: FileXCTestCase {
        targetTempDirRoot = workingDir.appendingPathComponent("Root")
        currentTargetTempDir = targetTempDirRoot.appendingPathComponent("Current.build")
        try fileManager.spt_createEmptyDir(currentTargetTempDir)
-        plugin = ThinningCreatorPlugin(targetTempDir: currentTargetTempDir, dirScanner: FileManager.default)
+        plugin = ThinningCreatorPlugin(
+            targetTempDir: currentTargetTempDir,
+            modeMarkerPath: "rc_marker.enabled",
+            dirScanner: FileManager.default)
    }

    func testReturnsEmptyExtraKeysForNoArtifacts() throws {
@@ -73,4 +76,62 @@ class ThinningCreatorPluginTests: FileXCTestCase {

        XCTAssertThrowsError(try plugin.extraMetaKeys(Self.sampleMeta))
    }
+
+    func testDefinesExtraMetaKeysForTargetsThatReusedArtifact() throws {
+        let otherTargetTempDir = targetTempDirRoot.appendingPathComponent("Other.build")
+        let marker = otherTargetTempDir.appendingPathComponent("rc_marker.enabled")
+        let reusedArtifact = otherTargetTempDir
+            .appendingPathComponent("xccache")
+            .appendingPathComponent("123")
+            .appendingPathExtension("zip")
+        try fileManager.spt_createEmptyFile(marker)
+        try fileManager.spt_createEmptyFile(reusedArtifact)
+
+        let extraKeys = try plugin.extraMetaKeys(Self.sampleMeta)
+
+        XCTAssertEqual(extraKeys, ["thinning_Other": "123"])
+    }
+
+    func testFailsGeneratingExtraMetaKeysForTwoArtifactsInTargetTempDir() throws {
+        let otherTargetTempDir = targetTempDirRoot.appendingPathComponent("Other.build")
+        let marker = otherTargetTempDir.appendingPathComponent("rc_marker.enabled")
+        let reusedArtifact1 = otherTargetTempDir
+            .appendingPathComponent("xccache")
+            .appendingPathComponent("001")
+            .appendingPathExtension("zip")
+        let reusedArtifact2 = otherTargetTempDir
+            .appendingPathComponent("xccache")
+            .appendingPathComponent("002")
+            .appendingPathExtension("zip")
+        try fileManager.spt_createEmptyFile(marker)
+        try fileManager.spt_createEmptyFile(reusedArtifact1)
+        try fileManager.spt_createEmptyFile(reusedArtifact2)
+
+        XCTAssertThrowsError(try plugin.extraMetaKeys(Self.sampleMeta))
+    }
+
+    func testDefinesExtraMetaKeysForGeneratedAndReusedArtifact() throws {
+        let otherTargetTempDir = targetTempDirRoot.appendingPathComponent("Generated.build")
+        let generatedArtifact = otherTargetTempDir
+            .appendingPathComponent("xccache")
+            .appendingPathComponent("produced")
+            .appendingPathComponent("000")
+            .appendingPathExtension("zip")
+        try fileManager.spt_createEmptyFile(generatedArtifact)
+        let reusedTargetTempDir = targetTempDirRoot.appendingPathComponent("Reused.build")
+        let marker = reusedTargetTempDir.appendingPathComponent("rc_marker.enabled")
+        let reusedArtifact = reusedTargetTempDir
+            .appendingPathComponent("xccache")
+            .appendingPathComponent("999")
+            .appendingPathExtension("zip")
+        try fileManager.spt_createEmptyFile(marker)
+        try fileManager.spt_createEmptyFile(reusedArtifact)
+
+        let extraKeys = try plugin.extraMetaKeys(Self.sampleMeta)
+
+        XCTAssertEqual(extraKeys, [
+            "thinning_Generated": "000",
+            "thinning_Reused": "999",
+        ])
+    }
 }
@@ -26,8 +26,9 @@ class PostbuildContextTests: FileXCTestCase {
    private static let SampleEnvs = [
        "TARGET_NAME": "TARGET_NAME",
        "TARGET_TEMP_DIR": "TARGET_TEMP_DIR",
-        "PLATFORM_PREFERRED_ARCH": "PLATFORM_PREFERRED_ARCH",
-        "OBJECT_FILE_DIR_normal": "OBJECT_FILE_DIR_normal" ,
+        "DERIVED_FILE_DIR": "DERIVED_FILE_DIR",
+        "ARCHS": "x86_64",
+        "OBJECT_FILE_DIR_normal": "/OBJECT_FILE_DIR_normal" ,
        "CONFIGURATION": "CONFIGURATION",
        "PLATFORM_NAME": "PLATFORM_NAME",
        "XCODE_PRODUCT_BUILD_VERSION": "XCODE_PRODUCT_BUILD_VERSION",
@@ -42,6 +43,7 @@ class PostbuildContextTests: FileXCTestCase {
        "DWARF_DSYM_FILE_NAME": "DWARF_DSYM_FILE_NAME",
        "BUILT_PRODUCTS_DIR": "BUILT_PRODUCTS_DIR",
        "DERIVED_SOURCES_DIR": "DERIVED_SOURCES_DIR",
+        "CURRENT_VARIANT": "normal",
    ]

    override func setUpWithError() throws {
@@ -87,4 +89,45 @@ class PostbuildContextTests: FileXCTestCase {

        XCTAssertEqual(context.action, .index)
    }
+
+    func testReadsSingleArch() throws {
+        var envs = Self.SampleEnvs
+        envs["ARCHS"] = "x86_64"
+        let context = try PostbuildContext(config, env: envs)
+
+        XCTAssertEqual(context.arch, "x86_64")
+    }
+
+    func testReadsFirstArch() throws {
+        var envs = Self.SampleEnvs
+        envs["ARCHS"] = "x86_64 arm64"
+        let context = try PostbuildContext(config, env: envs)
+
+        XCTAssertEqual(context.arch, "x86_64")
+    }
+
+    func testFailsForEmptyArch() throws {
+        var envs = Self.SampleEnvs
+        envs["ARCHS"] = ""
+
+        XCTAssertThrowsError(try PostbuildContext(config, env: envs))
+    }
+
+    func testFailsForMissingArch() throws {
+        var envs = Self.SampleEnvs
+        envs["ARCHS"] = nil
+
+        XCTAssertThrowsError(try PostbuildContext(config, env: envs))
+    }
+
+    func testFindTempDirForCustomVariant() throws {
+        var envs = Self.SampleEnvs
+        envs["ARCHS"] = "x86_64"
+        envs["CURRENT_VARIANT"] = "custom"
+        envs["OBJECT_FILE_DIR_custom"] = "/OBJECT_FILE_DIR_custom"
+
+        let context = try PostbuildContext(config, env: envs)
+
+        XCTAssertEqual(context.compilationTempDir, "/OBJECT_FILE_DIR_custom/x86_64")
+    }
 }
@@ -20,12 +20,14 @@
@testable import XCRemoteCache
 import XCTest

+// swiftlint:disable file_length
 // swiftlint:disable:next type_body_length
 class PostbuildTests: FileXCTestCase {
    private var postbuildContext = PostbuildContext(
        mode: .producer,
        targetName: "",
        targetTempDir: "",
+        derivedFilesDir: "",
        compilationTempDir: "",
        configuration: "",
        platform: "",
@@ -50,7 +52,10 @@ class PostbuildTests: FileXCTestCase {
        bundleDir: nil,
        derivedSourcesDir: "",
        thinnedTargets: [],
-        action: .build
+        action: .build,
+        modeMarkerPath: "",
+        overlayHeadersPath: "",
+        irrelevantDependenciesPaths: []
    )
    private var network = RemoteNetworkClientImpl(
        NetworkClientFake(fileManager: .default),
@@ -75,7 +80,9 @@ class PostbuildTests: FileXCTestCase {
        product: "/Product",
        source: "/Source",
        intermediate: "/Intermediate",
-        bundle: nil
+        derivedFiles: "/DerivedFiles",
+        bundle: nil,
+        skippedRegexes: []
    )
    private var overrideManager = FingerprintOverrideManagerImpl(
        overridingFileExtensions: ["swiftmodule"],
@@ -84,6 +91,7 @@ class PostbuildTests: FileXCTestCase {
    )
    private var modeController = CacheModeControllerFake()
    private var metaReader = JsonMetaReader(fileAccessor: FileManager.default)
+    private var metaWriter = JsonMetaWriter(fileWriter: FileManager.default, pretty: false)
    private static let SampleMeta = MainArtifactSampleMeta.defaults
    private var sampleMetaFile: URL!

@@ -122,6 +130,7 @@ class PostbuildTests: FileXCTestCase {
            dSYMOrganizer: DSYMOrganizerFake(dSYMFile: nil),
            modeController: modeController,
            metaReader: metaReader,
+            metaWriter: metaWriter,
            creatorPlugins: [],
            consumerPlugins: []
        )
@@ -151,6 +160,7 @@ class PostbuildTests: FileXCTestCase {
            dSYMOrganizer: DSYMOrganizerFake(dSYMFile: nil),
            modeController: modeController,
            metaReader: metaReader,
+            metaWriter: metaWriter,
            creatorPlugins: [],
            consumerPlugins: []
        )
@@ -178,6 +188,7 @@ class PostbuildTests: FileXCTestCase {
            dSYMOrganizer: dsymOrganizer,
            modeController: modeController,
            metaReader: metaReader,
+            metaWriter: metaWriter,
            creatorPlugins: [],
            consumerPlugins: []
        )
@@ -205,6 +216,7 @@ class PostbuildTests: FileXCTestCase {
            dSYMOrganizer: dsymOrganizer,
            modeController: modeController,
            metaReader: metaReader,
+            metaWriter: metaWriter,
            creatorPlugins: [],
            consumerPlugins: []
        )
@@ -242,6 +254,7 @@ class PostbuildTests: FileXCTestCase {
            dSYMOrganizer: dsymOrganizer,
            modeController: modeController,
            metaReader: metaReader,
+            metaWriter: metaWriter,
            creatorPlugins: [],
            consumerPlugins: []
        )
@@ -282,6 +295,7 @@ class PostbuildTests: FileXCTestCase {
            dSYMOrganizer: dsymOrganizer,
            modeController: modeController,
            metaReader: metaReader,
+            metaWriter: metaWriter,
            creatorPlugins: [],
            consumerPlugins: []
        )
@@ -307,6 +321,7 @@ class PostbuildTests: FileXCTestCase {
            dSYMOrganizer: DSYMOrganizerFake(dSYMFile: nil),
            modeController: fakeModeController,
            metaReader: metaReader,
+            metaWriter: metaWriter,
            creatorPlugins: [],
            consumerPlugins: []
        )
@@ -354,6 +369,7 @@ class PostbuildTests: FileXCTestCase {
            dSYMOrganizer: DSYMOrganizerFake(dSYMFile: nil),
            modeController: modeController,
            metaReader: metaReader,
+            metaWriter: metaWriter,
            creatorPlugins: [plugin],
            consumerPlugins: []
        )
@@ -385,6 +401,7 @@ class PostbuildTests: FileXCTestCase {
            dSYMOrganizer: DSYMOrganizerFake(dSYMFile: nil),
            modeController: modeController,
            metaReader: metaReader,
+            metaWriter: metaWriter,
            creatorPlugins: [plugin],
            consumerPlugins: []
        )
@@ -417,6 +434,7 @@ class PostbuildTests: FileXCTestCase {
            dSYMOrganizer: DSYMOrganizerFake(dSYMFile: nil),
            modeController: modeController,
            metaReader: metaReader,
+            metaWriter: metaWriter,
            creatorPlugins: [],
            consumerPlugins: [consumerPlugin]
        )
@@ -454,6 +472,7 @@ class PostbuildTests: FileXCTestCase {
            dSYMOrganizer: DSYMOrganizerFake(dSYMFile: nil),
            modeController: modeController,
            metaReader: metaReader,
+            metaWriter: metaWriter,
            creatorPlugins: [],
            consumerPlugins: [consumerPlugin]
        )
@@ -485,6 +504,7 @@ class PostbuildTests: FileXCTestCase {
            dSYMOrganizer: DSYMOrganizerFake(dSYMFile: nil),
            modeController: modeController,
            metaReader: metaReader,
+            metaWriter: metaWriter,
            creatorPlugins: [],
            consumerPlugins: [consumerPlugin]
        )
@@ -518,6 +538,7 @@ class PostbuildTests: FileXCTestCase {
            dSYMOrganizer: DSYMOrganizerFake(dSYMFile: nil),
            modeController: modeController,
            metaReader: metaReader,
+            metaWriter: metaWriter,
            creatorPlugins: [],
            consumerPlugins: []
        )
@@ -550,6 +571,7 @@ class PostbuildTests: FileXCTestCase {
            dSYMOrganizer: DSYMOrganizerFake(dSYMFile: nil),
            modeController: modeController,
            metaReader: metaReader,
+            metaWriter: metaWriter,
            creatorPlugins: [],
            consumerPlugins: []
        )
@@ -558,5 +580,67 @@ class PostbuildTests: FileXCTestCase {
        try postbuild.deleteFingerprintOverrides()

        XCTAssertFalse(fileManager.fileExists(atPath: previousFingerprintOverride.path))
-    } // swiftlint:disable:next file_length
+    }
+
+    func testUploadingMeta() throws {
+        let postbuild = Postbuild(
+            context: postbuildContext,
+            networkClient: network,
+            remapper: remapper,
+            fingerprintAccumulator: fingerprintGenerator,
+            artifactsOrganizer: organizer,
+            artifactCreator: artifactCreator,
+            fingerprintSyncer: syncer,
+            dependenciesReader: dependenciesReader,
+            dependencyProcessor: processor,
+            fingerprintOverrideManager: overrideManager,
+            dSYMOrganizer: DSYMOrganizerFake(dSYMFile: nil),
+            modeController: modeController,
+            metaReader: metaReader,
+            metaWriter: metaWriter,
+            creatorPlugins: [],
+            consumerPlugins: []
+        )
+
+        try postbuild.performMetaUpload(meta: Self.SampleMeta, for: "33")
+
+
+        let data = try network.fetch(.meta(commit: "33"))
+        let downloadedMeta = try metaReader.read(data: data)
+
+        XCTAssertEqual(downloadedMeta, Self.SampleMeta)
+    }
+
+    func testUploadingMetaWithNewPluginKeys() throws {
+        let plugin = MetaAppenderArtifactCreatorPlugin(["New": "Value"])
+        let postbuild = Postbuild(
+            context: postbuildContext,
+            networkClient: network,
+            remapper: remapper,
+            fingerprintAccumulator: fingerprintGenerator,
+            artifactsOrganizer: organizer,
+            artifactCreator: artifactCreator,
+            fingerprintSyncer: syncer,
+            dependenciesReader: dependenciesReader,
+            dependencyProcessor: processor,
+            fingerprintOverrideManager: overrideManager,
+            dSYMOrganizer: DSYMOrganizerFake(dSYMFile: nil),
+            modeController: modeController,
+            metaReader: metaReader,
+            metaWriter: metaWriter,
+            creatorPlugins: [plugin],
+            consumerPlugins: []
+        )
+        var meta = Self.SampleMeta
+        meta.pluginsKeys = ["Previous": "Value"]
+        var expectedMeta = meta
+        expectedMeta.pluginsKeys = ["New": "Value"]
+
+        try postbuild.performMetaUpload(meta: meta, for: "33")
+
+        let data = try network.fetch(.meta(commit: "33"))
+        let downloadedMeta = try metaReader.read(data: data)
+
+        XCTAssertEqual(downloadedMeta, expectedMeta)
+    }
 }
@@ -62,7 +62,8 @@ class PrebuildTests: FileXCTestCase {
            forceCached: false,
            compilationHistoryFile: compilationHistory,
            turnOffRemoteCacheOnFirstTimeout: true,
-            targetName: ""
+            targetName: "",
+            overlayHeadersPath: ""
        )
        contextCached = PrebuildContext(
            targetTempDir: sampleURL,
@@ -74,7 +75,8 @@ class PrebuildTests: FileXCTestCase {
            forceCached: true,
            compilationHistoryFile: compilationHistory,
            turnOffRemoteCacheOnFirstTimeout: true,
-            targetName: ""
+            targetName: "",
+            overlayHeadersPath: ""
        )
        organizer = ArtifactOrganizerFake(artifactRoot: artifactsRoot, unzippedExtension: "unzip")
        globalCacheSwitcher = InMemoryGlobalCacheSwitcher()
@@ -238,7 +240,8 @@ class PrebuildTests: FileXCTestCase {
            forceCached: false,
            compilationHistoryFile: compilationHistory,
            turnOffRemoteCacheOnFirstTimeout: true,
-            targetName: ""
+            targetName: "",
+            overlayHeadersPath: ""
        )

        let prebuild = Prebuild(
@@ -268,7 +271,8 @@ class PrebuildTests: FileXCTestCase {
            forceCached: false,
            compilationHistoryFile: compilationHistory,
            turnOffRemoteCacheOnFirstTimeout: true,
-            targetName: ""
+            targetName: "",
+            overlayHeadersPath: ""
        )
        metaContent = try generateMeta(fingerprint: generator.generate(), filekey: "1")
        let downloadedArtifactPackage = artifactsRoot.appendingPathComponent("1")
@@ -330,7 +334,8 @@ class PrebuildTests: FileXCTestCase {
            forceCached: false,
            compilationHistoryFile: compilationHistory,
            turnOffRemoteCacheOnFirstTimeout: false,
-            targetName: ""
+            targetName: "",
+            overlayHeadersPath: ""
        )
        try globalCacheSwitcher.enable(sha: "1")
        let prebuild = Prebuild(
@@ -28,6 +28,7 @@ class FileLLDBInitPatcherTests: XCTestCase {
    private var patcher: FileLLDBInitPatcher!

    override func setUp() {
+        super.setUp()
        accessor = FileAccessorFake(mode: .normal)
        patcher = FileLLDBInitPatcher(
            file: lldbInitPath,
@@ -0,0 +1,63 @@
+// Copyright (c) 2021 Spotify AB.
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+@testable import XCRemoteCache
+import XCTest
+
+class XcodeProjBuildSettingsIntegrateAppenderTests: XCTestCase {
+    private let rootURL: URL = "/root"
+    private let binariesDir: URL = "/binaries"
+    private var buildSettings: BuildSettings!
+    private var binaries: XCRCBinariesPaths!
+
+    override func setUp() {
+        super.setUp()
+        buildSettings = BuildSettings()
+        binaries = XCRCBinariesPaths(
+            prepare: binariesDir.appendingPathComponent("xcprepare"),
+            cc: binariesDir.appendingPathComponent("xccc"),
+            swiftc: binariesDir.appendingPathComponent("xcswiftc"),
+            libtool: binariesDir.appendingPathComponent("xclibtool"),
+            ld: binariesDir.appendingPathComponent("xcld"),
+            ldplusplus: binariesDir.appendingPathComponent("xcldplusplus"),
+            prebuild: binariesDir.appendingPathComponent("xcprebuild"),
+            postbuild: binariesDir.appendingPathComponent("xcpostbuild")
+        )
+    }
+
+    func testProducerSettingFakeSrcRoot() throws {
+        let mode: Mode = .producer
+        let fakeRootURL: URL = "/xxxxxxxxxxP"
+        let appender = XcodeProjBuildSettingsIntegrateAppender(mode: mode, repoRoot: rootURL, fakeSrcRoot: fakeRootURL)
+        let result = appender.appendToBuildSettings(buildSettings: buildSettings, wrappers: binaries)
+        let resultURL = try XCTUnwrap(result["XCRC_FAKE_SRCROOT"] as? String)
+
+        XCTAssertEqual(resultURL, fakeRootURL.path)
+    }
+
+    func testConsumerSettingFakeSrcRoot() throws {
+        let mode: Mode = .consumer
+        let fakeRootURL: URL = "/xxxxxxxxxxC"
+        let appender = XcodeProjBuildSettingsIntegrateAppender(mode: mode, repoRoot: rootURL, fakeSrcRoot: fakeRootURL)
+        let result = appender.appendToBuildSettings(buildSettings: buildSettings, wrappers: binaries)
+        let resultURL: String = try XCTUnwrap(result["XCRC_FAKE_SRCROOT"] as? String)
+
+        XCTAssertEqual(resultURL, fakeRootURL.path)
+    }
+}
@@ -62,4 +62,19 @@ class SwiftcContextTests: FileXCTestCase {

        XCTAssertEqual(context.mode, .consumer(commit: .unavailable))
    }
+
+    func testProducerModeWhenFileWithCommitShaExistsIsResolvedToProducerFast() throws {
+        config.mode = .producerFast
+        let context = try SwiftcContext(config: config, input: input)
+
+        XCTAssertEqual(context.mode, .producerFast)
+    }
+
+    func testProducerModeWhenFileWithCommitShaDoesntExxistIsResolvedToProducer() throws {
+        config.mode = .producerFast
+        try fileManager.spt_deleteItem(at: remoteCommitFile)
+        let context = try SwiftcContext(config: config, input: input)
+
+        XCTAssertEqual(context.mode, .producer)
+    }
 }
@@ -21,8 +21,8 @@
 import XCTest

 class SwiftcFilemapInputEditorTests: FileXCTestCase {
-
-    private let sampleInfo = SwiftCompilationInfo(info: SwiftModuleCompilationInfo(
+    private let sampleInfo = SwiftCompilationInfo(
+        info: SwiftModuleCompilationInfo(
        dependencies: nil,
        swiftDependencies: "/"
    ), files: [])
@@ -65,17 +65,19 @@ class SwiftcFilemapInputEditorTests: FileXCTestCase {
           }
        }
        """#.data(using: .utf8)!
-        let expectedInfo = SwiftCompilationInfo(info: SwiftModuleCompilationInfo(
-            dependencies: "/master.d",
-            swiftDependencies: "/master.swiftdeps"
-        ), files: [
-            SwiftFileCompilationInfo(
-                file: "/file1.swift",
-                dependencies: "/file1.d",
-                object: "/file1.o",
-                swiftDependencies: "/file1.swiftdeps"
+        let expectedInfo = SwiftCompilationInfo(
+            info: SwiftModuleCompilationInfo(
+                dependencies: "/master.d",
+                swiftDependencies: "/master.swiftdeps"
            ),
-        ])
+            files: [
+                SwiftFileCompilationInfo(
+                    file: "/file1.swift",
+                    dependencies: "/file1.d",
+                    object: "/file1.o",
+                    swiftDependencies: "/file1.swiftdeps"
+                ),
+            ])
        try fileManager.spt_writeToFile(atPath: inputFile.path, contents: infoContentData)

        let readInfo = try editor.read()
@@ -93,17 +95,18 @@ class SwiftcFilemapInputEditorTests: FileXCTestCase {
    }

    func testWritingSavesContentWithOptionalParameters() throws {
-        let extendedInfo = SwiftCompilationInfo(info: SwiftModuleCompilationInfo(
-            dependencies: "/master.d",
-            swiftDependencies: "/master.swiftdeps"
-        ), files: [
-            SwiftFileCompilationInfo(
-                file: "/file1.swift",
-                dependencies: "/file1.d",
-                object: "/file1.o",
-                swiftDependencies: "/file1.swiftdeps"
-            ),
-        ])
+        let extendedInfo = SwiftCompilationInfo(
+            info: SwiftModuleCompilationInfo(
+                dependencies: "/master.d",
+                swiftDependencies: "/master.swiftdeps"
+            ), files: [
+                SwiftFileCompilationInfo(
+                    file: "/file1.swift",
+                    dependencies: "/file1.d",
+                    object: "/file1.o",
+                    swiftDependencies: "/file1.swiftdeps"
+                ),
+            ])

        try editor.write(extendedInfo)

@@ -190,4 +190,45 @@ class SwiftcOrchestratorTests: XCTestCase {

        XCTAssertNotNil(shellOutSpy.switchedProcess)
    }
+
+    func testForFailedCompilationMockInProducerFastModeBuildsArtifactObjCHeader() throws {
+        let swiftc = SwiftcMock(mockingResult: .forceFallback)
+        let orchestrator = SwiftcOrchestrator(
+            mode: .producerFast,
+            swiftc: swiftc,
+            swiftcCommand: "",
+            objcHeaderOutput: objcHeaderURL,
+            moduleOutput: moduleOutputURL,
+            arch: "archTest",
+            artifactBuilder: artifactBuilder,
+            producerFallbackCommandProcessors: [],
+            invocationStorage: invocationStorage,
+            shellOut: shellOutSpy
+        )
+
+        try orchestrator.run()
+
+        XCTAssertEqual(artifactBuilder.addedObjCHeaders, ["archTest": [objcHeaderURL]])
+    }
+
+    func testSuccessedMockInProducerFastModeDoesntFillObjCHeader() throws {
+        let swiftc = SwiftcMock(mockingResult: .success)
+        let orchestrator = SwiftcOrchestrator(
+            mode: .producerFast,
+            swiftc: swiftc,
+            swiftcCommand: "",
+            objcHeaderOutput: objcHeaderURL,
+            moduleOutput: moduleOutputURL,
+            arch: "arch",
+            artifactBuilder: artifactBuilder,
+            producerFallbackCommandProcessors: [],
+            invocationStorage: invocationStorage,
+            shellOut: shellOutSpy
+        )
+
+        try orchestrator.run()
+
+        XCTAssertEqual(artifactBuilder.addedObjCHeaders, [:])
+    }
+
 }
@@ -277,7 +277,12 @@ class SwiftcTests: FileXCTestCase {
        let artifactObjCHeader = URL(fileURLWithPath: "/cachedArtifact/include/archTest/Target-Swift.h")
        let artifactSwiftmodule = URL(fileURLWithPath: "/cachedArtifact/swiftmodule/archTest/Target.swiftmodule")
        let artifactSwiftdoc = URL(fileURLWithPath: "/cachedArtifact/swiftmodule/archTest/Target.swiftdoc")
-        let artifactSwiftSourceInfo = URL(fileURLWithPath: "/cachedArtifact/swiftmodule/archTest/Target.swiftsourceinfo")
+        let artifactSwiftSourceInfo = URL(
+            fileURLWithPath: "/cachedArtifact/swiftmodule/archTest/Target.swiftsourceinfo"
+        )
+        let artifactSwiftInterfaceInfo = URL(
+            fileURLWithPath: "/cachedArtifact/swiftmodule/archTest/Target.swiftinterface"
+        )

        artifactOrganizer = ArtifactOrganizerFake(artifactRoot: artifactRoot)
        let swiftc = Swiftc(
@@ -301,12 +306,14 @@ class SwiftcTests: FileXCTestCase {
        let swiftModuleURL = swiftModuleFiles.0[.swiftmodule]
        let swiftDocURL = swiftModuleFiles.0[.swiftdoc]
        let swiftSourceInfoURL = swiftModuleFiles.0[.swiftsourceinfo]
+        let swiftInterfaceURL = swiftModuleFiles.0[.swiftinterface]
        let swiftHeaderURL = swiftModuleFiles.1

        XCTAssertEqual(swiftModuleURL, artifactSwiftmodule)
        XCTAssertEqual(swiftDocURL, artifactSwiftdoc)
        XCTAssertEqual(swiftSourceInfoURL, artifactSwiftSourceInfo)
        XCTAssertEqual(swiftHeaderURL, artifactObjCHeader)
+        XCTAssertEqual(swiftInterfaceURL, artifactSwiftInterfaceInfo)
    }


@@ -457,5 +464,5 @@ class SwiftcTests: FileXCTestCase {
        )

        XCTAssertNoThrow(try swiftc.mockCompilation())
-    }
+    } // swiftlint:disable:next file_length
 }
@@ -28,7 +28,7 @@ class TemplateBasedCCWrapperBuilderTests: FileXCTestCase {
    private static let history = "history.compile"
    private static let prebuild = "prebuild.d"
    private static let commitSha = "321"
-    private static let timeout = 5.0
+    private static let timeout = 10.0

    static let xccc: URL = {
        let fileManager = FileManager.default
@@ -47,7 +47,8 @@ class TemplateBasedCCWrapperBuilderTests: FileXCTestCase {
        let app = appDir.appendingPathComponent("xccc")
        try? fileManager.removeItem(at: appDir)
        try? FileManager.default.createDirectory(at: appDir, withIntermediateDirectories: true, attributes: nil)
-        try? builder.compile(to: app, commitSha: commitSha)
+        // swiftlint:disable:next force_try
+        try! builder.compile(to: app, commitSha: commitSha)
        return app
    }()

@@ -332,11 +333,31 @@ class TemplateBasedCCWrapperBuilderTests: FileXCTestCase {
        XCTAssertNotEqual(newFileOutputData, Data())
    }

+    func testPCHCompilationFallbacks() throws {
+        // Marker is empty to mimic the new file scenario
+        let pchFile = directory.appendingPathComponent("input.pch")
+        createValidPCHFile(pchFile)
+        arguments = ["-x", "objective-c-header", "-MF", dependencyFile.path, "-o", outputFile.path, pchFile.path]
+
+        try shellExec(Self.xccc.path, args: arguments, inDir: directory.path)
+
+        XCTAssertTrue(fileManager.fileExists(atPath: outputFile.path))
+    }
+
    /// Creates a simple C code in the location
    private func createValidCFile(_ location: URL) {
        fileManager.createFile(atPath: location.path, contents: "int main(){}".data(using: .utf8), attributes: nil)
    }

+    /// Creates a simple PCH code in the location
+    private func createValidPCHFile(_ location: URL) {
+        fileManager.createFile(
+            atPath: location.path,
+            contents: "#import <Availability.h>".data(using: .utf8),
+            attributes: nil
+        )
+    }
+
    /// Creates a C code that requires extra CUSTOM_STR clang macro to compile
    private func createInvalidCFile(_ location: URL) {
        fileManager.createFile(
@@ -0,0 +1,33 @@
+// Copyright (c) 2021 Spotify AB.
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+@testable import XCRemoteCache
+import XCTest
+import Yams
+
+class ModeTests: XCTestCase {
+
+    func testProducerFast() throws {
+        let yaml = "producer-fast"
+        let decoder = YAMLDecoder(encoding: .utf8)
+        let mode: Mode = try decoder.decode(from: yaml)
+
+        XCTAssertEqual(mode, .producerFast)
+    }
+}
@@ -0,0 +1,88 @@
+// Copyright (c) 2022 Spotify AB.
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+@testable import XCRemoteCache
+import XCTest
+
+class XCRemoteCacheConfigReaderTests: XCTestCase {
+
+    private var fileReader: FileAccessorFake!
+    private var reader: XCRemoteCacheConfigReader!
+
+    override func setUp() {
+        super.setUp()
+        fileReader = FileAccessorFake(mode: .normal)
+        reader = XCRemoteCacheConfigReader(srcRootPath: "/", fileReader: fileReader)
+    }
+
+    func testReadsFromExtraConfig() throws {
+        try fileReader.write(toPath: "/.rcinfo", contents: "cache_addresses: [test]")
+
+        let config = try reader.readConfiguration()
+
+        XCTAssertEqual(config.cacheAddresses, ["test"])
+    }
+
+    func testOverridesExtraConfigFromExtraFile() throws {
+        try fileReader.write(toPath: "/.rcinfo", contents: "cache_addresses: [test]")
+        try fileReader.write(toPath: "/user.rcinfo", contents: "cache_addresses: [user]")
+
+        let config = try reader.readConfiguration()
+
+        XCTAssertEqual(config.cacheAddresses, ["user"])
+    }
+
+    func testReadsExtraConfigMultipleTimes() throws {
+        try fileReader.write(toPath: "/.rcinfo", contents: "cache_addresses: [test]")
+        try fileReader.write(toPath: "/user.rcinfo", contents: """
+        cache_addresses: [user]
+        extra_configuration_file: user2.rcinfo
+        """)
+        try fileReader.write(toPath: "/user2.rcinfo", contents: "cache_addresses: [user2]")
+
+        let config = try reader.readConfiguration()
+
+        XCTAssertEqual(config.cacheAddresses, ["user2"])
+    }
+
+    func testBreaksImportingExtraConfigIfReachingALoop() throws {
+        try fileReader.write(toPath: "/.rcinfo", contents: "cache_addresses: [test]")
+        try fileReader.write(toPath: "/user.rcinfo", contents: """
+        cache_addresses: [user]
+        extra_configuration_file: .rcinfo
+        """)
+
+        let config = try reader.readConfiguration()
+
+        XCTAssertEqual(config.cacheAddresses, ["user"])
+    }
+
+    func testBreaksImportingExtraConfigIfFileDoesntExist() throws {
+        try fileReader.write(toPath: "/.rcinfo", contents: "cache_addresses: [test]")
+        try fileReader.write(toPath: "/user.rcinfo", contents: """
+        cache_addresses: [user]
+        extra_configuration_file: nonexisting.rcinfo
+        """)
+
+        let config = try reader.readConfiguration()
+
+        XCTAssertEqual(config.cacheAddresses, ["user"])
+        XCTAssertEqual(config.extraConfigurationFile, "nonexisting.rcinfo")
+    }
+}
@@ -0,0 +1,139 @@
+// Copyright (c) 2021 Spotify AB.
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+@testable import XCRemoteCache
+
+import XCTest
+
+class DependenciesReaderPerformanceTest: XCTestCase {
+
+    private static let resourcesSubdirectory = "TestData/Dependencies/DependenciesReaderPerformanceTest"
+
+    private func pathForTestData(name: String) throws -> URL {
+        return try XCTUnwrap(Bundle.module.url(
+            forResource: name,
+            withExtension: "d",
+            subdirectory: DependenciesReaderPerformanceTest.resourcesSubdirectory
+        ))
+    }
+
+    func testFindDependenciesPerformance() throws {
+        let file = try pathForTestData(name: "dependencies")
+        let reader = FileDependenciesReader(file, accessor: FileManager.default)
+
+        self.measure { // 0.005
+            do {
+                _ = try reader.findDependencies()
+            } catch {
+                print("Error reading dependencies")
+            }
+        }
+    }
+
+    func testReadRawFilePerformance() throws {
+        let file = try pathForTestData(name: "dependencies")
+        let reader = FileDependenciesReader(file, accessor: FileManager.default)
+
+        self.measure { // 0.002
+            do {
+                _ = try reader.readRaw()
+            } catch {
+                print("Error reading dependencies")
+            }
+        }
+    }
+
+    func testGetFileDataPerformance() throws {
+        let file = try pathForTestData(name: "dependencies")
+        let reader = FileDependenciesReader(file, accessor: FileManager.default)
+
+        self.measure { // 0.00008
+            do {
+                _ = try reader.getFileData()
+            } catch {
+                print("Error reading dependencies")
+            }
+        }
+    }
+
+    func testGetFileStringPerformance() throws {
+        let file = try pathForTestData(name: "dependencies")
+        let reader = FileDependenciesReader(file, accessor: FileManager.default)
+        let fileData = try reader.getFileData()
+
+        self.measure { // 0.00002
+            do {
+                _ = try reader.getFileStringFromData(fileData: fileData)
+            } catch {
+                print("Error reading dependencies")
+            }
+        }
+    }
+
+    func testGetYamlPerformance() throws { // 0.222
+        let file = try pathForTestData(name: "dependencies")
+        let reader = FileDependenciesReader(file, accessor: FileManager.default)
+        let fileData = try reader.getFileData()
+        let fileString = try reader.getFileStringFromData(fileData: fileData)
+
+        self.measure { // 0.0022
+            do {
+                _ = try reader.getYaml(fileString: fileString)
+            } catch {
+                print("Error reading dependencies")
+            }
+        }
+    }
+
+    func testParseDependencyFileListUsingUTF8View() throws {
+        let file = try pathForTestData(name: "dependencies")
+        let reader = FileDependenciesReader(file, accessor: FileManager.default)
+        let fileData = try reader.getFileData()
+        let fileString = try reader.getFileStringFromData(fileData: fileData)
+        let yaml = try reader.getYaml(fileString: fileString)
+
+        guard let dependencies = yaml["dependencies"] else {
+            XCTAssertTrue(false)
+            return
+        }
+
+        self.measure { // 0.004
+            let deps = reader.parseDependencyFileList(dependencies)
+            XCTAssertTrue(deps.count == 1000)
+        }
+    }
+
+    func testDeprecatedParseDependenciesFilesListOfAnObjectUsingUTF8View() throws {
+        let file = try pathForTestData(name: "dependencies")
+        let reader = FileDependenciesReader(file, accessor: FileManager.default)
+        let fileData = try reader.getFileData()
+        let fileString = try reader.getFileStringFromData(fileData: fileData)
+        let yaml = try reader.getYaml(fileString: fileString)
+
+        guard let dependencies = yaml["/This/Is/A/Path/To/Some/Object/objectfile.o"] else {
+            XCTAssertTrue(false)
+            return
+        }
+
+        self.measure { // 0.00048
+            let deps = reader.parseDependencyFileList(dependencies)
+            XCTAssertTrue(deps.count == 100)
+        }
+    }
+}
@@ -29,53 +29,120 @@ class DependenciesRemapperCompositeTests: XCTestCase {
        StringDependenciesRemapper.Mapping(generic: "$(PWD)", local: "/pwd"),
    ]

-    func testNoRemappersIsTransparent() {
+    func testNoRemappersIsTransparent() throws {
        let remapper = DependenciesRemapperComposite([])

-        let genericPath = remapper.replace(localPaths: ["/tmp/root/some.swift"])
+        let genericPath = try remapper.replace(localPaths: ["/tmp/root/some.swift"])

        XCTAssertEqual(genericPath, ["/tmp/root/some.swift"])
    }

-    func testOneRemapperReplacesLocalPaths() {
+    func testOneRemapperReplacesLocalPaths() throws {
        let remapper = DependenciesRemapperComposite([
            StringDependenciesRemapper(mappings: mappings1),
        ])

-        let genericPath = remapper.replace(localPaths: ["/tmp/root/some.swift"])
+        let genericPath = try remapper.replace(localPaths: ["/tmp/root/some.swift"])

        XCTAssertEqual(genericPath, ["$(SRC_ROOT)/some.swift"])
    }

-    func testOneRemapperReplacesGenericPaths() {
+    func testOneRemapperReplacesGenericPaths() throws {
        let remapper = DependenciesRemapperComposite([
            StringDependenciesRemapper(mappings: mappings1),
        ])

-        let localPath = remapper.replace(genericPaths: ["$(SRC_ROOT)/some.swift"])
+        let localPath = try remapper.replace(genericPaths: ["$(SRC_ROOT)/some.swift"])

        XCTAssertEqual(localPath, ["/tmp/root/some.swift"])
    }

-    func testTwoRemappersReplacesLocalPaths() {
+    func testTwoRemappersReplacesLocalPaths() throws {
        let remapper = DependenciesRemapperComposite([
            StringDependenciesRemapper(mappings: mappings1),
            StringDependenciesRemapper(mappings: mappings2),
        ])

-        let genericPath = remapper.replace(localPaths: ["/tmp/root/some.swift", "/pwd/other.swift"])
+        let genericPath = try remapper.replace(localPaths: ["/tmp/root/some.swift", "/pwd/other.swift"])

        XCTAssertEqual(genericPath, ["$(SRC_ROOT)/some.swift", "$(PWD)/other.swift"])
    }

-    func testOneRemappersReplacesGenericPaths() {
+    func testOneRemappersReplacesGenericPaths() throws {
        let remapper = DependenciesRemapperComposite([
            StringDependenciesRemapper(mappings: mappings1),
            StringDependenciesRemapper(mappings: mappings2),
        ])

-        let localPath = remapper.replace(genericPaths: ["$(SRC_ROOT)/some.swift", "$(PWD)/other.swift"])
+        let localPath = try remapper.replace(genericPaths: ["$(SRC_ROOT)/some.swift", "$(PWD)/other.swift"])

        XCTAssertEqual(localPath, ["/tmp/root/some.swift", "/pwd/other.swift"])
    }
+
+    func testRemapsMultipleMatchingMappers() throws {
+        let remapper = DependenciesRemapperComposite([
+            StringDependenciesRemapper(mappings: [
+                StringDependenciesRemapper.Mapping(
+                    generic: "$(ROOT)",
+                    local: "/root"
+                ),
+            ]),
+            StringDependenciesRemapper(mappings: [
+                StringDependenciesRemapper.Mapping(
+                    generic: "$(SPECIFIC)",
+                    local: "$(ROOT)/specific"
+                ),
+            ]),
+        ])
+        let localPaths = ["/root/specific/file"]
+
+        let genericPaths = try remapper.replace(localPaths: localPaths)
+
+        XCTAssertEqual(genericPaths, ["$(SPECIFIC)/file"])
+    }
+
+    func testRemapsBackToLocalWithRevertedRemappersOrder() throws {
+        let remapper = DependenciesRemapperComposite([
+            StringDependenciesRemapper(mappings: [
+                StringDependenciesRemapper.Mapping(
+                    generic: "$(ROOT)",
+                    local: "/root"
+                ),
+            ]),
+            StringDependenciesRemapper(mappings: [
+                StringDependenciesRemapper.Mapping(
+                    generic: "$(SPECIFIC)",
+                    local: "$(ROOT)/specific"
+                ),
+            ]),
+        ])
+        let genericPaths = ["$(SPECIFIC)/file"]
+
+        let localPaths = try remapper.replace(genericPaths: genericPaths)
+
+        XCTAssertEqual(localPaths, ["/root/specific/file"])
+    }
+
+    func testRemappingTwoMappingsBackAndForthIsIdentical() throws {
+        let remapper = DependenciesRemapperComposite([
+            StringDependenciesRemapper(mappings: [
+                StringDependenciesRemapper.Mapping(
+                    generic: "$(ROOT)",
+                    local: "/root"
+                ),
+            ]),
+            StringDependenciesRemapper(mappings: [
+                StringDependenciesRemapper.Mapping(
+                    generic: "$(SPECIFIC)",
+                    local: "$(ROOT)/specific"
+                ),
+            ]),
+        ])
+        let localPaths = ["/root/specific/file"]
+
+        let genericPaths = try remapper.replace(localPaths: localPaths)
+        let remappedLocalPaths = try remapper.replace(genericPaths: genericPaths)
+
+        XCTAssertEqual(localPaths, remappedLocalPaths)
+    }
 }
@@ -0,0 +1,47 @@
+// Copyright (c) 2021 Spotify AB.
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+@testable import XCRemoteCache
+import XCTest
+
+class FileDependenciesWriterTests: XCTestCase {
+
+    private func generateTempFileURL(name: String = #function) throws -> URL {
+        let directory = NSTemporaryDirectory()
+        return try NSURL.fileURL(withPathComponents: [directory, name]).unwrap()
+    }
+
+    func testWriteDependencyWithSpace() throws {
+        let url = try generateTempFileURL()
+        let writer = FileDependenciesWriter(url, accessor: FileManager.default)
+
+        try writer.writeGeneric(dependencies: [
+            "/SomePath/Pods/Target Support Files/lottie-ios/lottie-ios-dummy.m",
+        ])
+
+        let expectedContent = """
+        dependencies: /SomePath/Pods/Target\\ Support\\ Files/lottie-ios/lottie-ios-dummy.m
+
+        """
+
+        let content = String(data: try Data(contentsOf: url), encoding: .utf8)
+
+        XCTAssertEqual(content, expectedContent)
+    }
+}
@@ -20,24 +20,28 @@
@testable import XCRemoteCache
 import XCTest

-class DependencyProcessorImplTests: XCTestCase {
+class DependencyProcessorImplTests: FileXCTestCase {

    let processor = DependencyProcessorImpl(
        xcode: "/Xcode",
        product: "/Product",
        source: "/Source",
        intermediate: "/Intermediate",
-        bundle: "/Bundle"
+        derivedFiles: "/DerivedFiles",
+        bundle: "/Bundle",
+        skippedRegexes: []
    )

-    func testIntermediateFileIsSkippedForProductAndSourceSubdirectory() {
+    func testIntermediateFileIsskippedRegexesForProductAndSourceSubdirectory() {
        let intermediateFile: URL = "/Intermediate/some"
        let processor = DependencyProcessorImpl(
            xcode: "/Xcode",
            product: "/",
            source: "/",
            intermediate: "/Intermediate",
-            bundle: nil
+            derivedFiles: "/DerivedFiles",
+            bundle: nil,
+            skippedRegexes: []
        )

        XCTAssertEqual(
@@ -46,14 +50,16 @@ class DependencyProcessorImplTests: XCTestCase {
        )
    }

-    func testBundleFileIsSkippedForProductAndSourceSubdirectory() {
+    func testBundleFileIsskippedRegexesForProductAndSourceSubdirectory() {
        let bundleFile: URL = "/Bundle/some"
        let processor = DependencyProcessorImpl(
            xcode: "/Xcode",
            product: "/",
            source: "/",
            intermediate: "/Intermediate",
-            bundle: "/Bundle"
+            derivedFiles: "/DerivedFiles",
+            bundle: "/Bundle",
+            skippedRegexes: []
        )

        XCTAssertEqual(
@@ -62,6 +68,22 @@ class DependencyProcessorImplTests: XCTestCase {
        )
    }

+    func testFiltersOutGeneratedSwiftHeaders() throws {
+        let dependencies = processor.process([
+            "/DerivedFiles/ModuleName-Swift.h",
+        ])
+
+        XCTAssertEqual(dependencies, [])
+    }
+
+    func testFiltersOutDerivedFile() throws {
+        let dependencies = processor.process([
+            "/DerivedFiles/output.h",
+        ])
+
+        XCTAssertEqual(dependencies, [])
+    }
+
    func testFiltersOutProductModulemap() throws {
        let dependencies = processor.process([
            "/Product/some.modulemap",
@@ -70,6 +92,14 @@ class DependencyProcessorImplTests: XCTestCase {
        XCTAssertEqual(dependencies, [])
    }

+    func testDoesNotFilterOutOtherProductModulemap() throws {
+        let dependencies = processor.process([
+            "/ProductOther/some.modulemap",
+        ])
+
+        XCTAssertEqual(dependencies, [.init(url: "/ProductOther/some.modulemap", type: .unknown)])
+    }
+
    func testDoesNotFilterOutNonProductModulemap() throws {
        let dependencies = processor.process([
            "/Source/some.modulemap",
@@ -109,4 +139,152 @@ class DependencyProcessorImplTests: XCTestCase {

        XCTAssertEqual(dependencies, [.init(url: "/xxx/some", type: .unknown)])
    }
+
+    func testFiltersOutIntermediateBySymlink() throws {
+        let sampleDir = try prepareTempDir()
+
+        let intermediateDirReal = sampleDir.appendingPathComponent("Intermediate")
+        let symlink = sampleDir.appendingPathComponent("symlink")
+        let someFilename = "some"
+
+        let processor = DependencyProcessorImpl(
+            xcode: "/Xcode",
+            product: "/Product",
+            source: "/Source",
+            intermediate: intermediateDirReal,
+            derivedFiles: "/DerivedFiles",
+            bundle: "/Bundle",
+            skippedRegexes: []
+        )
+
+        let intermediateFileSymlink = createSymlink(
+            filename: someFilename,
+            sourceDir: symlink,
+            destinationDir: intermediateDirReal
+        )
+
+        let dependencies = processor.process([
+            intermediateFileSymlink,
+        ])
+
+        XCTAssertEqual(dependencies, [])
+    }
+
+    func testDoesNotFilterOutSourceBySymlink() throws {
+        let sampleDir = try prepareTempDir()
+
+        let sourceDirReal = sampleDir.appendingPathComponent("Source")
+        let symlink = sampleDir.appendingPathComponent("symlink")
+        let someFilename = "some"
+
+        let processor = DependencyProcessorImpl(
+            xcode: "/Xcode",
+            product: "/Product",
+            source: sourceDirReal,
+            intermediate: "/Intermediate",
+            derivedFiles: "/DerivedFiles",
+            bundle: "/Bundle",
+            skippedRegexes: []
+        )
+
+        let sourceFileSymlink = createSymlink(
+            filename: someFilename,
+            sourceDir: symlink,
+            destinationDir: sourceDirReal
+        )
+
+        let dependencies = processor.process([
+            sourceFileSymlink,
+        ])
+
+        XCTAssertEqual(dependencies, [.init(url: sourceFileSymlink, type: .source)])
+    }
+
+    /**
+     * Creates Symlink from sourceDir to destinationDir and creates empty file inside it
+     * return URL with symbolic link from sourceDir to destinationDir
+     */
+    fileprivate func createSymlink(filename: String, sourceDir: URL, destinationDir: URL) -> URL {
+        let fileMng = FileManager.default
+
+        XCTAssertNoThrow(try fileMng.spt_forceSymbolicLink(
+            at: sourceDir,
+            withDestinationURL: destinationDir
+        ))
+        XCTAssertNoThrow(try fileMng.spt_createEmptyFile(destinationDir.appendingPathComponent(filename)))
+
+        return sourceDir.appendingPathComponent(filename)
+    }
+
+    func testSkipsCustomizedDerivedDirFileUnderSources() {
+        let derivedFile: URL = "/DerivedFiles/Module-Swift.h"
+        let processor = DependencyProcessorImpl(
+            xcode: "/Xcode",
+            product: "/",
+            source: "/",
+            intermediate: "/Intermediate",
+            derivedFiles: "/DerivedFiles",
+            bundle: nil,
+            skippedRegexes: []
+        )
+
+        XCTAssertEqual(
+            processor.process([derivedFile]),
+            []
+        )
+    }
+
+    func testSkippsFilesWithFullMatch() {
+        let source: URL = "/someFile.m"
+        let processor = DependencyProcessorImpl(
+            xcode: "/Xcode",
+            product: "/",
+            source: "/",
+            intermediate: "/Intermediate",
+            derivedFiles: "/DerivedFiles",
+            bundle: nil,
+            skippedRegexes: ["/someFile\\.m"]
+        )
+
+        XCTAssertEqual(
+            processor.process([source]),
+            []
+        )
+    }
+
+    func testSkippsFilesWithPartialMatch() {
+        let derivedModulemap: URL = "/module.modulemap"
+        let processor = DependencyProcessorImpl(
+            xcode: "/Xcode",
+            product: "/product",
+            source: "/",
+            intermediate: "/Intermediate",
+            derivedFiles: "/DerivedFiles",
+            bundle: nil,
+            skippedRegexes: ["\\.modulemap$"]
+        )
+
+        XCTAssertEqual(
+            processor.process([derivedModulemap]),
+            []
+        )
+    }
+
+    func testDoesntSkipFileIfInvalidRegex() {
+        let source: URL = "/someFile.m"
+        let processor = DependencyProcessorImpl(
+            xcode: "/Xcode",
+            product: "/product",
+            source: "/",
+            intermediate: "/Intermediate",
+            derivedFiles: "/DerivedFiles",
+            bundle: nil,
+            skippedRegexes: ["\\"]
+        )
+
+        XCTAssertEqual(
+            processor.process([source]),
+            [.init(url: source, type: .source)]
+        )
+    }
 }
@@ -27,6 +27,7 @@ class FileFingerprintSyncerTests: FileXCTestCase {
    private var swiftmoduleDir: URL!

    override func setUpWithError() throws {
+        try super.setUpWithError()
        syncer = FileFingerprintSyncer(
            fingerprintOverrideExtension: "md5",
            dirAccessor: fileManager,
@@ -0,0 +1,70 @@
+// Copyright (c) 2021 Spotify AB.
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+@testable import XCRemoteCache
+import XCTest
+
+class OverlayDependenciesRemapperTests: XCTestCase {
+    private let overlayReader = OverlayReaderFake(
+        mappings: [.init(virtual: "/file.h", local: "/Intermediate/Some/file.h")]
+    )
+
+    func testMappingFromLocalToGeneric() throws {
+        let remapper = OverlayDependenciesRemapper(overlayReader: overlayReader)
+
+        let dependencies = try remapper.replace(localPaths: ["/Intermediate/Some/file.h"])
+        XCTAssertEqual(dependencies, ["/file.h"])
+    }
+
+    func testMappingFromGenericToLocal() throws {
+        let remapper = OverlayDependenciesRemapper(overlayReader: overlayReader)
+
+
+        let dependencies = try remapper.replace(genericPaths: ["/file.h"])
+        XCTAssertEqual(dependencies, ["/Intermediate/Some/file.h"])
+    }
+
+    func testGenericDependenciesAreNotMerged() throws {
+        let remapper = OverlayDependenciesRemapper(overlayReader: overlayReader)
+
+
+        let dependencies = try remapper.replace(localPaths: ["/Intermediate/Some/file.h", "/file.h"])
+        XCTAssertEqual(dependencies, ["/file.h", "/file.h"])
+    }
+
+    func testLocalDependenciesAreNotMerged() throws {
+        let remapper = OverlayDependenciesRemapper(overlayReader: overlayReader)
+
+
+        let dependencies = try remapper.replace(genericPaths: ["/Intermediate/Some/file.h", "/file.h"])
+        XCTAssertEqual(dependencies, ["/Intermediate/Some/file.h", "/Intermediate/Some/file.h"])
+    }
+
+    func testMappingsAreReadOnce() throws {
+        let remapper = OverlayDependenciesRemapper(overlayReader: overlayReader)
+
+        let firstDependencies = try remapper.replace(localPaths: ["/Intermediate/Some/file.h"])
+        // Update mappings in-fly to verify the previous value is cached in a remapper
+        overlayReader.mappings = []
+        let secondDependencies = try remapper.replace(localPaths: ["/Intermediate/Some/file.h"])
+
+        XCTAssertEqual(firstDependencies, ["/file.h"])
+        XCTAssertEqual(secondDependencies, ["/file.h"])
+    }
+}
@@ -0,0 +1,94 @@
+// Copyright (c) 2021 Spotify AB.
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+@testable import XCRemoteCache
+import XCTest
+
+class JsonOverlayReaderTests: FileXCTestCase {
+    private static let resourcesSubdirectory = "TestData/Dependencies/JsonOverlayReaderTests"
+
+    func testParsingWithSuccess() throws {
+        let file = try pathForTestData(name: "overlayReaderDefault")
+        let reader = JsonOverlayReader(file, mode: .strict, fileReader: FileManager.default)
+        let mappings = try reader.provideMappings()
+
+        let expectedMappings = [
+            OverlayMapping(
+                virtual: "/DerivedDataProducts/Target1.framework/Headers/Target1.h",
+                local: "/Path/Target1/Target1.h"
+            ),
+            OverlayMapping(
+                virtual: "/DerivedDataProducts/Target2.framework/Modules/module.modulemap",
+                local: "/DerivedDataIntermediate/Target2.build/module.modulemap"
+            ),
+        ]
+        XCTAssertEqual(Set(mappings), Set(expectedMappings))
+    }
+
+    func testFailsWithMissingFileForStrictMode() throws {
+        let file: URL = "nonExiting"
+        let reader = JsonOverlayReader(file, mode: .strict, fileReader: FileManager.default)
+
+        XCTAssertThrowsError(try reader.provideMappings())
+    }
+
+    func testReturnsEmpptyMappingForMissingFileForBestEffortMode() throws {
+        let file: URL = "nonExiting"
+        let reader = JsonOverlayReader(file, mode: .bestEffort, fileReader: FileManager.default)
+
+        let mappings = try reader.provideMappings()
+
+        XCTAssertEqual(mappings, [])
+    }
+
+    func testParsingEmptyOverlay() throws {
+        let file = try pathForTestData(name: "overlayReaderEmpty")
+        let reader = JsonOverlayReader(file, mode: .strict, fileReader: FileManager.default)
+        let mappings = try reader.provideMappings()
+
+        XCTAssertEqual(mappings, [])
+    }
+
+    func testInvalidJsonDoesntThrowForBestEffortMode() throws {
+        let workingDir = try prepareTempDir()
+        let file = workingDir.appendingPathExtension("overlay.json")
+        try fileManager.spt_createEmptyFile(file)
+        let reader = JsonOverlayReader(file, mode: .bestEffort, fileReader: fileManager)
+        let mappings = try reader.provideMappings()
+
+        XCTAssertEqual(mappings, [])
+    }
+
+    func testInvalidJsonThrowsForStrictMode() throws {
+        let workingDir = try prepareTempDir()
+        let file = workingDir.appendingPathExtension("overlay.json")
+        try fileManager.spt_createEmptyFile(file)
+        let reader = JsonOverlayReader(file, mode: .strict, fileReader: fileManager)
+
+        XCTAssertThrowsError(try reader.provideMappings())
+    }
+
+    private func pathForTestData(name: String) throws -> URL {
+        return try XCTUnwrap(Bundle.module.url(
+            forResource: name,
+            withExtension: "json",
+            subdirectory: JsonOverlayReaderTests.resourcesSubdirectory
+        ))
+    }
+}
@@ -0,0 +1,94 @@
+// Copyright (c) 2021 Spotify AB.
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+@testable import XCRemoteCache
+import XCTest
+
+class PathDependenciesRemapperFactoryTests: XCTestCase {
+    private var factory: PathDependenciesRemapperFactory!
+
+    override func setUp() {
+        super.setUp()
+        factory = PathDependenciesRemapperFactory()
+    }
+
+    func testMappingsFromEnvMaps() throws {
+        let remapper = try factory.build(
+            orderKeys: ["SRC_ROOT"],
+            envs: ["SRC_ROOT": "/tmp/root"],
+            customMappings: [:]
+        )
+
+        let localPaths = try remapper.replace(genericPaths: ["$(SRC_ROOT)/some.swift"])
+        XCTAssertEqual(localPaths, ["/tmp/root/some.swift"])
+    }
+
+    func testMappingsGenericWhenMappingHasParentDir() throws {
+        let remapper = try factory.build(
+            orderKeys: ["SRC_ROOT"],
+            envs: ["SRC_ROOT": "/tmp/root/extra/.."],
+            customMappings: [:]
+        )
+
+        let localPaths = try remapper.replace(genericPaths: ["$(SRC_ROOT)/some.swift"])
+        XCTAssertEqual(localPaths, ["/tmp/root/some.swift"])
+    }
+
+    func testMappingsLocalWhenMappingHasParentDir() throws {
+        let remapper = try factory.build(
+            orderKeys: ["SRC_ROOT"],
+            envs: ["SRC_ROOT": "/tmp/root/excessive/.."],
+            customMappings: [:]
+        )
+
+        let localPaths = try remapper.replace(localPaths: ["/tmp/root/some.swift"])
+        XCTAssertEqual(localPaths, ["$(SRC_ROOT)/some.swift"])
+    }
+
+    func testMissingEnvIsSkipped() throws {
+        XCTAssertNoThrow(
+            try factory.build(
+                orderKeys: ["SRC_ROOT"],
+                envs: ["NO_SRC_ROOT": ""],
+                customMappings: [:]
+            )
+        )
+    }
+
+    func testBuildingRemapperWithMergedCustomMappings() throws {
+        let remapper = try factory.build(
+            orderKeys: ["PWD"],
+            envs: ["PWD": "/some"],
+            customMappings: ["TMP": "/tmp"]
+        )
+
+        let genericPaths = try remapper.replace(localPaths: ["/some/repoFile.swift", "/tmp/externalFile.swift"])
+        XCTAssertEqual(genericPaths, ["$(PWD)/repoFile.swift", "$(TMP)/externalFile.swift"])
+    }
+
+    func testFailsBuildingRemapperWithConflictedMappings() throws {
+        XCTAssertThrowsError(
+            try factory.build(
+            orderKeys: ["PWD"],
+            envs: ["PWD": "/some"],
+            customMappings: ["PWD": "/other"]
+            )
+        )
+    }
+}
@@ -30,34 +30,34 @@ class StringDependenciesRemapperTests: XCTestCase {
        remapper = StringDependenciesRemapper(mappings: mappings)
    }

-    func testMappingSingleGenericPathReplacesWithLocalPath() {
-        let localPaths = remapper.replace(genericPaths: ["$(SRC_ROOT)/some.swift"])
+    func testMappingSingleGenericPathReplacesWithLocalPath() throws {
+        let localPaths = try remapper.replace(genericPaths: ["$(SRC_ROOT)/some.swift"])

        XCTAssertEqual(localPaths, ["/tmp/root/some.swift"])
    }

-    func testRewritingSingleLocalPathReplacesWithGenericPath() {
-        let genericPaths = remapper.replace(localPaths: ["/tmp/root/some.swift"])
+    func testRewritingSingleLocalPathReplacesWithGenericPath() throws {
+        let genericPaths = try remapper.replace(localPaths: ["/tmp/root/some.swift"])

        XCTAssertEqual(genericPaths, ["$(SRC_ROOT)/some.swift"])
    }

-    func testRewritingLocalToGenericAndLocalIsIdentical() {
+    func testRewritingLocalToGenericAndLocalIsIdentical() throws {
        let inputLocalPaths = ["/tmp/root/some.swift"]

-        let genericPaths = remapper.replace(localPaths: inputLocalPaths)
-        let localPaths = remapper.replace(genericPaths: genericPaths)
+        let genericPaths = try remapper.replace(localPaths: inputLocalPaths)
+        let localPaths = try remapper.replace(genericPaths: genericPaths)

        XCTAssertEqual(localPaths, inputLocalPaths)
    }

-    func testRewritingUnrelatedDirReturnsInputPath() {
-        let genericPaths = remapper.replace(localPaths: ["/other/some.swift"])
+    func testRewritingUnrelatedDirReturnsInputPath() throws {
+        let genericPaths = try remapper.replace(localPaths: ["/other/some.swift"])

        XCTAssertEqual(genericPaths, ["/other/some.swift"])
    }

-    func testMultipleMatchesTakeTheFirstMapping() {
+    func testMultipleMatchesTakeTheFirstMapping() throws {
        let mappings: [StringDependenciesRemapper.Mapping] = [
            .init(generic: "$(SRC_ROOT)", local: "/tmp/root"),
            .init(generic: "$(PWD)", local: "/tmp"),
@@ -65,22 +65,34 @@ class StringDependenciesRemapperTests: XCTestCase {
        remapper = StringDependenciesRemapper(mappings: mappings)


-        let genericPaths = remapper.replace(localPaths: ["/tmp/root/some.swift", "/tmp/extra.swift"])
+        let genericPaths = try remapper.replace(localPaths: ["/tmp/root/some.swift", "/tmp/extra.swift"])

        XCTAssertEqual(genericPaths, ["$(SRC_ROOT)/some.swift", "$(PWD)/extra.swift"])
    }

-    func testMappingsFromEnvMaps() throws {
-        remapper = try StringDependenciesRemapper.buildFromEnvs(keys: ["SRC_ROOT"], envs: ["SRC_ROOT": "/tmp/root"])
+    func testMappingsLocalPathsIsDoneInOrder() throws {
+        let mappings: [StringDependenciesRemapper.Mapping] = [
+            .init(generic: "$(TMP)", local: "/tmp"),
+            .init(generic: "$(ROOT)", local: "$(TMP)/root"),
+        ]
+        remapper = StringDependenciesRemapper(mappings: mappings)

-        let localPaths = remapper.replace(genericPaths: ["$(SRC_ROOT)/some.swift"])
+
+        let genericPaths = try remapper.replace(localPaths: ["/tmp/root/some.swift"])
+
+        XCTAssertEqual(genericPaths, ["$(ROOT)/some.swift"])
+    }
+
+    func testMappingsGenericPathsIsDoneInReversedOrder() throws {
+        let mappings: [StringDependenciesRemapper.Mapping] = [
+            .init(generic: "$(TMP)", local: "/tmp"),
+            .init(generic: "$(ROOT)", local: "$(TMP)/root"),
+        ]
+        remapper = StringDependenciesRemapper(mappings: mappings)
+
+
+        let localPaths = try remapper.replace(genericPaths: ["$(ROOT)/some.swift"])

        XCTAssertEqual(localPaths, ["/tmp/root/some.swift"])
    }
-
-    func testInvalidMappingsFromEnvFAils() throws {
-        XCTAssertThrowsError(
-            try StringDependenciesRemapper.buildFromEnvs(keys: ["SRC_ROOT"], envs: ["NO_SRC_ROOT": ""])
-        )
-    }
 }
@@ -27,6 +27,7 @@ class TargetDependenciesReaderTests: XCTestCase {
    private var reader: TargetDependenciesReader!

    override func setUp() {
+        super.setUp()
        dirAccessor = DirAccessorFake()
        /// A Factory that builds a faked dependency reader that returns a single dependency,
        /// a basename of the input .d file and the ".swift" extension
@@ -27,6 +27,7 @@ class CopyDiskCopierTests: FileXCTestCase {
    private var emptySourceFile: URL!

    override func setUpWithError() throws {
+        try super.setUpWithError()
        workingDir = try prepareTempDir()
        emptySourceFile = workingDir.appendingPathComponent("source")
        try fileManager.spt_writeToFile(atPath: emptySourceFile.path, contents: Data())
@@ -24,7 +24,7 @@ class EnvironmentFingerprintGeneratorTests: XCTestCase {

    private static let defaultENV = [
        "GCC_PREPROCESSOR_DEFINITIONS": "GCC",
-        "CLANG_PROFILE_DATA_DIRECTORY": "CLANG",
+        "CLANG_COVERAGE_MAPPING": "YES",
        "TARGET_NAME": "TARGET",
        "CONFIGURATION": "CONG",
        "PLATFORM_NAME": "PLAT",
@@ -33,18 +33,23 @@ class EnvironmentFingerprintGeneratorTests: XCTestCase {
        "DYLIB_COMPATIBILITY_VERSION": "2",
        "DYLIB_CURRENT_VERSION": "3",
        "PRODUCT_MODULE_NAME": "4",
+        "ARCHS": "AR",
    ]
    /// Corresponds to EnvironmentFingerprintGenerator.version
    private static let currentVersion = "5"

    private var config: XCRemoteCacheConfig!
-    private var generator: FingerprintAccumulator!
+    private var generator: FingerprintAccumulator! {
+        return generatorFake
+    }
+
+    private var generatorFake: FingerprintAccumulatorFake!
    private var fingerprintGenerator: EnvironmentFingerprintGenerator!

    override func setUp() {
        super.setUp()
        config = XCRemoteCacheConfig(sourceRoot: "")
-        generator = FingerprintAccumulatorFake()
+        generatorFake = FingerprintAccumulatorFake()
        fingerprintGenerator = EnvironmentFingerprintGenerator(
            configuration: config,
            env: Self.defaultENV,
@@ -55,7 +60,7 @@ class EnvironmentFingerprintGeneratorTests: XCTestCase {
    func testConsidersDefaultEnvs() throws {
        let fingerprint = try fingerprintGenerator.generateFingerprint()

-        XCTAssertEqual(fingerprint, "GCC,CLANG,TARGET,CONG,PLAT,XC,1,2,3,4,\(Self.currentVersion)")
+        XCTAssertEqual(fingerprint, "GCC,YES,TARGET,CONG,PLAT,XC,1,2,3,4,AR,\(Self.currentVersion)")
    }

    func testFingerprintIncludesVersionAsLastComponent() throws {
@@ -73,7 +78,7 @@ class EnvironmentFingerprintGeneratorTests: XCTestCase {

        let fingerprint = try fingerprintGenerator.generateFingerprint()

-        XCTAssertEqual(fingerprint, ",,,,,,,,,,\(Self.currentVersion)")
+        XCTAssertEqual(fingerprint, ",,,,,,,,,,,\(Self.currentVersion)")
    }

    func testConsidersCustomEnvs() throws {
@@ -89,6 +94,13 @@ class EnvironmentFingerprintGeneratorTests: XCTestCase {

        let fingerprint = try fingerprintGenerator.generateFingerprint()

-        XCTAssertEqual(fingerprint, "GCC,CLANG,TARGET,CONG,PLAT,XC,1,2,3,4,CUSTOM_VALUE,\(Self.currentVersion)")
+        XCTAssertEqual(fingerprint, "GCC,YES,TARGET,CONG,PLAT,XC,1,2,3,4,AR,CUSTOM_VALUE,\(Self.currentVersion)")
+    }
+
+    func testFingerprintIsGeneratedOnce() throws {
+        let fingerprint1 = try fingerprintGenerator.generateFingerprint()
+        let fingerprint2 = try fingerprintGenerator.generateFingerprint()
+        XCTAssertEqual(fingerprint1, fingerprint2)
+        XCTAssertEqual(generatorFake.generateCallsCount, 1)
    }
 }
@@ -0,0 +1,61 @@
+// Copyright (c) 2021 Spotify AB.
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+@testable import XCRemoteCache
+import XCTest
+
+class JsonMetaWriterTests: XCTestCase {
+
+    func testWritesToFileWithFilekeyFilename() throws {
+        let fileAccessor = FileAccessorFake(mode: .normal)
+        let writer = JsonMetaWriter(fileWriter: fileAccessor, pretty: false)
+        let workingDir: URL = "/"
+        let meta = MainArtifactSampleMeta.defaults
+
+        let url = try writer.write(MainArtifactSampleMeta.defaults, locationDir: workingDir)
+
+        XCTAssertEqual(url, workingDir.appendingPathComponent(meta.fileKey).appendingPathExtension("json"))
+    }
+
+    func testWritesMetaInValidFormat() throws {
+        let fileAccessor = FileAccessorFake(mode: .normal)
+        let writer = JsonMetaWriter(fileWriter: fileAccessor, pretty: false)
+        let reader = JsonMetaReader(fileAccessor: fileAccessor)
+        let workingDir: URL = "/"
+        let meta = MainArtifactSampleMeta.defaults
+
+        let url = try writer.write(MainArtifactSampleMeta.defaults, locationDir: workingDir)
+
+        let readMeta = try reader.read(localFile: url)
+        XCTAssertEqual(readMeta, meta)
+    }
+
+    func testWritesPrettyMetaInValidFormat() throws {
+        let fileAccessor = FileAccessorFake(mode: .normal)
+        let writer = JsonMetaWriter(fileWriter: fileAccessor, pretty: true)
+        let reader = JsonMetaReader(fileAccessor: fileAccessor)
+        let workingDir: URL = "/"
+        let meta = MainArtifactSampleMeta.defaults
+
+        let url = try writer.write(MainArtifactSampleMeta.defaults, locationDir: workingDir)
+
+        let readMeta = try reader.read(localFile: url)
+        XCTAssertEqual(readMeta, meta)
+    }
+}
--- a/Show More
+++ b/Show More