Merge pull request #185 from polac24/bartosz/20230306-watch-library

Support universal binary framework

.github/workflows/ci.yaml

@@ -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: ${{ '13.1' }}
+      XCODE_VERSION: ${{ '14.2' }}
     steps:
       - name: Select Xcode
         run: "sudo xcode-select -s /Applications/Xcode_$XCODE_VERSION.app"

.github/workflows/docs.yaml

@@ -0,0 +1,24 @@
+name: Docs
+
+on:
+  push:
+    branches:
+      - master
+
+jobs:
+  docs:
+    runs-on: macos-12
+    env:
+      XCODE_VERSION: ${{ '14.2' }}
+    steps:
+      - uses: actions/checkout@v2
+      - name: Select Xcode
+        run: "sudo xcode-select -s /Applications/Xcode_$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

.github/workflows/release.yaml

@@ -6,9 +6,9 @@ on:
 jobs:
   macOS:
     name: Add macOS binaries to release
-    runs-on: macOS-latest
+    runs-on: macos-12
     env:
-      XCODE_VERSION: ${{ '13.1' }}
+      XCODE_VERSION: ${{ '14.2' }}
     steps:
       - name: Select Xcode
         run: "sudo xcode-select -s /Applications/Xcode_$XCODE_VERSION.app"

.swiftlint.yml

@@ -5,7 +5,6 @@ disabled_rules:
   - superfluous_disable_command # Disabled since we disable some rules pre-emptively to avoid issues in the future
   - todo                        # Temporarily disabled. We have too many right now hiding real issues :(
   - nesting                     # Does not make sense anymore since Swift 4 uses nested `CodingKeys` enums for example
-  - trailing_dot_in_comments    # Triggers warnings for generated file headers
 
 opt_in_rules:
   - anyobject_protocol
@@ -64,6 +63,8 @@ excluded:
   - docs/
   - fastlane/
   - DerivedData/
+  - e2eTests/XCRemoteCacheSample/Pods
+  - e2eTests/StandaloneSampleApp
 
 attributes:
   always_on_same_line:
@@ -88,6 +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
@@ -124,6 +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

Package.resolved

@@ -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"
         }
       }
     ]

Package.swift

@@ -1,4 +1,5 @@
 // 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(
@@ -31,9 +33,13 @@ let package = Package(
             dependencies: ["XCRemoteCache"]
         ),
         .target(
-            name: "xclibtool",
+            name: "xclibtoolSupport",
             dependencies: ["XCRemoteCache"]
         ),
+        .target(
+            name: "xclibtool",
+            dependencies: ["XCRemoteCache", "xclibtoolSupport"]
+        ),
         .target(
             name: "xcpostbuild",
             dependencies: ["XCRemoteCache"]
@@ -49,15 +55,23 @@ 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"],
             resources: [.copy("TestData")]
         ),
+        .testTarget(
+            name: "xclibtoolSupportTests",
+            dependencies: ["xclibtoolSupport"]
+        ),
     ]
 )

README.md

@@ -8,6 +8,7 @@ _XCRemoteCache is a remote cache tool for Xcode projects. It reuses target artif
 [![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://github.com/spotify/XCRemoteCache/workflows/Docs/badge.svg)](https://spotify.github.io/XCRemoteCache/documentation/xcremotecache/)
 
 - [How and Why?](#how-and-why)
   * [Accurate target input files](#accurate-target-input-files)
@@ -195,7 +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>
@@ -264,7 +267,42 @@ $ 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._
+
+##### 7. Generalize `-Swift.h` (Optional only if using static library with a bridging header with public `NS_ENUM` exposed from ObjC)
+
+If a static library target contains a mixed target with a bridging header exposing an enum from ObjC in a public Swift API, your custom script that moves `*-Swift.h` to the shared location, it should also move `*-Swift.h.md5` next to it.
+
+Example:
+
+##### Existing script (Before):
+
+```shell
+ditto "${SCRIPT_INPUT_FILE_0}" "${SCRIPT_OUTPUT_FILE_0}"
+```
+
+where
+* `SCRIPT_INPUT_FILE_0="$(DERIVED_SOURCES_DIR)/$(SWIFT_OBJC_INTERFACE_HEADER_NAME)"`
+* `SCRIPT_OUTPUT_FILE_0="$(BUILT_PRODUCTS_DIR)/include/$(PRODUCT_MODULE_NAME)/$(SWIFT_OBJC_INTERFACE_HEADER_NAME)"`
+
+##### Correct script (After):
+
+```shell
+ditto "${SCRIPT_INPUT_FILE_0}" "${SCRIPT_OUTPUT_FILE_0}"
+[ -f "${SCRIPT_INPUT_FILE_1}" ] && ditto "${SCRIPT_INPUT_FILE_1}" "${SCRIPT_OUTPUT_FILE_1}" || rm "${SCRIPT_OUTPUT_FILE_1}"
+```
+
+where
+* `SCRIPT_INPUT_FILE_0="$(DERIVED_SOURCES_DIR)/$(SWIFT_OBJC_INTERFACE_HEADER_NAME)"`
+* `SCRIPT_INPUT_FILE_1="$(DERIVED_SOURCES_DIR)/$(SWIFT_OBJC_INTERFACE_HEADER_NAME).md5"`
+* `SCRIPT_OUTPUT_FILE_0="$(BUILT_PRODUCTS_DIR)/include/$(PRODUCT_MODULE_NAME)/$(SWIFT_OBJC_INTERFACE_HEADER_NAME)"`
+* `SCRIPT_OUTPUT_FILE_1="$(BUILT_PRODUCTS_DIR)/include/$(PRODUCT_MODULE_NAME)/$(SWIFT_OBJC_INTERFACE_HEADER_NAME).md5"`
+
+Note: This step is not required if at least one of these is true:
+
+* you build a framework (not a static library)
+* you don't expose `NS_ENUM` type from ObjC to Swift via a bridging header
+
 
 ## A full list of configuration parameters:
 
@@ -288,13 +326,15 @@ _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` | ⬜️ |
+| `upload_batch_size` | Maximum number of simultaneous requests. 0 means no limits | `0` | ⬜️ |
 | `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 | `[]` | ⬜️ |
@@ -308,11 +348,14 @@ _Note that for the `producer` mode, the prebuild build phase and `xccc`, `xcld`,
 | `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
 
@@ -350,6 +393,8 @@ 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
 ...
@@ -403,12 +448,14 @@ Note: This setup is not recommended and may not be supported in future XCRemoteC
 * 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) 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
 

Rakefile

@@ -10,7 +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
@@ -72,6 +72,22 @@ task :build, [:configuration, :arch, :sdks, :is_archive] do |task, args|
   end
 end
 
+desc 'Build release artifacts'
+task :prepare_release do
+  system("rm -rf releases && rm -rf tmp")
+  Rake::Task['build'].invoke("release", "x86_64-apple-macosx")
+  system("mkdir -p tmp && unzip releases/XCRemoteCache.zip -d tmp/xcremotecache-x86_64")
+  system("rm -rf releases")
+  Rake::Task['build'].invoke("release", "arm64-apple-macosx")
+  system("rake 'build[release, arm64-apple-macosx]'")
+  system("mkdir -p tmp && unzip releases/XCRemoteCache.zip -d tmp/xcremotecache-arm64")
+  system("rm -rf releases")
+  system("mkdir -p releases && zip -jr releases/XCRemoteCache-macOS-x86_64.zip LICENSE README.md tmp/xcremotecache-x86_64")
+  system("zip -jr releases/XCRemoteCache-macOS-arm64.zip LICENSE README.md tmp/xcremotecache-arm64")
+  system("mkdir -p tmp/xcremotecache && ls tmp/xcremotecache-x86_64 | xargs -I {} lipo -create -output tmp/xcremotecache/{} tmp/xcremotecache-x86_64/{} tmp/xcremotecache-arm64/{}")
+  system("zip -jr releases/XCRemoteCache-macOS-arm64-x86_64.zip LICENSE README.md tmp/xcremotecache")
+end
+
 desc 'run tests with SPM'
 task :test do
   # Running tests

Sources/XCRemoteCache/Artifacts/ArtifactCreator.swift

@@ -42,6 +42,7 @@ class BuildArtifactCreator: ArtifactSwiftProductsBuilderImpl, ArtifactCreator {
     private let modulesFolderPath: String
     private let dSYMPath: URL
     private let metaWriter: MetaWriter
+    private let artifactProcessor: ArtifactProcessor
     private let fileManager: FileManager
 
     init(
@@ -52,6 +53,7 @@ class BuildArtifactCreator: ArtifactSwiftProductsBuilderImpl, ArtifactCreator {
         modulesFolderPath: String,
         dSYMPath: URL,
         metaWriter: MetaWriter,
+        artifactProcessor: ArtifactProcessor,
         fileManager: FileManager
     ) {
         self.buildDir = buildDir
@@ -62,6 +64,7 @@ class BuildArtifactCreator: ArtifactSwiftProductsBuilderImpl, ArtifactCreator {
         self.fileManager = fileManager
         self.dSYMPath = dSYMPath
         self.metaWriter = metaWriter
+        self.artifactProcessor = artifactProcessor
         super.init(workingDir: tempDir, moduleName: moduleName, fileManager: fileManager)
     }
 
@@ -87,6 +90,7 @@ class BuildArtifactCreator: ArtifactSwiftProductsBuilderImpl, ArtifactCreator {
     /// - Parameter tempDir: Temp location to organize file hierarchy in the artifact
     /// - returns: URLs to include into the artifact package
     fileprivate func prepareSwiftArtifacts(tempDir: URL) throws -> [URL] {
+        try artifactProcessor.process(localArtifact: tempDir)
         var artifacts: [URL] = []
 
         // Add optional directory with generated ObjC headers

Sources/XCRemoteCache/Artifacts/ArtifactOrganizer.swift

@@ -31,7 +31,7 @@ enum ArtifactOrganizerLocationPreparationResult: Equatable {
     case preparedForArtifact(artifact: URL)
 }
 
-/// Prepares .zip artifact for the local operations
+/// Prepares existing .zip artifact for the local operations
 protocol ArtifactOrganizer {
     /// Prepares the location for the artifact unzipping
     /// - Parameter fileKey: artifact fileKey that corresponds to the zip filename on the remote cache server
@@ -48,10 +48,13 @@ protocol ArtifactOrganizer {
 
 class ZipArtifactOrganizer: ArtifactOrganizer {
     private let cacheDir: URL
+    // all processors that should "prepare" the unzipped raw artifact
+    private let artifactProcessors: [ArtifactProcessor]
     private let fileManager: FileManager
 
-    init(targetTempDir: URL, fileManager: FileManager) {
+    init(targetTempDir: URL, artifactProcessors: [ArtifactProcessor], fileManager: FileManager) {
         cacheDir = targetTempDir.appendingPathComponent("xccache")
+        self.artifactProcessors = artifactProcessors
         self.fileManager = fileManager
     }
 
@@ -93,6 +96,10 @@ class ZipArtifactOrganizer: ArtifactOrganizer {
         // when the command was interrupted (internal crash or `kill -9` signal)
         let tempDestination = destinationURL.appendingPathExtension("tmp")
         try Zip.unzipFile(artifact, destination: tempDestination, overwrite: true, password: nil)
+
+        try artifactProcessors.forEach { processor in
+            try processor.process(rawArtifact: tempDestination)
+        }
         try fileManager.moveItem(at: tempDestination, to: destinationURL)
         return destinationURL
     }

Sources/XCRemoteCache/Artifacts/ArtifactProcessor.swift

@@ -0,0 +1,80 @@
+// 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.
+
+import Foundation
+
+
+/// Performs a pre/postprocessing on an artifact package
+/// Could be a place for file reorganization (to support legacy package formats) and/or
+/// remapp absolute paths in some package files
+protocol ArtifactProcessor {
+    /// Processes a raw artifact in a directory. Raw artifact is a format of an artifact
+    /// that is stored in a remote cache server (generic)
+    /// - Parameter rawArtifact: directory that contains raw artifact content
+    func process(rawArtifact: URL) throws
+
+    /// Processes a local artifact in a directory
+    /// - Parameter localArtifact: directory that contains local (machine-specific) artifact content
+    func process(localArtifact: URL) throws
+}
+
+/// Processes downloaded artifact by replacing generic paths in generated ObjC headers placed in ./include
+class UnzippedArtifactProcessor: ArtifactProcessor {
+    /// All directories in an artifact that should be processed by path remapping
+    private static let remappingDirs = ["include"]
+    private let fileRemapper: FileDependenciesRemapper
+    private let dirScanner: DirScanner
+
+    init(fileRemapper: FileDependenciesRemapper, dirScanner: DirScanner) {
+        self.fileRemapper = fileRemapper
+        self.dirScanner = dirScanner
+    }
+
+    private func findProcessingEligableFiles(path: String) throws -> [URL] {
+        let remappingURL = URL(fileURLWithPath: path)
+        let allFiles = try dirScanner.recursiveItems(at: remappingURL)
+        return allFiles.filter({ !$0.isHidden })
+    }
+
+    /// Replaces all generic paths in a raw artifact's `include` dir with
+    /// absolute paths, specific for a given machine and configuration
+    /// - Parameter rawArtifact: raw artifact location
+    func process(rawArtifact url: URL) throws {
+        for remappingDir in Self.remappingDirs {
+            let remappingPath = url.appendingPathComponent(remappingDir).path
+            let allFiles = try findProcessingEligableFiles(path: remappingPath)
+            try allFiles.forEach(fileRemapper.remap(fromGeneric:))
+        }
+    }
+
+    func process(localArtifact url: URL) throws {
+        for remappingDir in Self.remappingDirs {
+            let remappingPath = url.appendingPathComponent(remappingDir).path
+            let allFiles = try findProcessingEligableFiles(path: remappingPath)
+            try allFiles.forEach(fileRemapper.remap(fromLocal:))
+        }
+    }
+}
+
+fileprivate extension URL {
+    // Recognize hidden files starting with a dot
+    var isHidden: Bool {
+        lastPathComponent.hasPrefix(".")
+    }
+}

Sources/XCRemoteCache/Artifacts/ArtifactSwiftProductsBuilder.swift

@@ -88,7 +88,7 @@ class ArtifactSwiftProductsBuilderImpl: ArtifactSwiftProductsBuilder {
             throw ArtifactSwiftProductsBuilderError.populatingNonExistingObjCHeader
         }
         try fileManager.createDirectory(at: moduleObjCURL, withIntermediateDirectories: true, attributes: nil)
-        try fileManager.spt_forceLinkItem(at: headerURL, to: headerArtifactURL)
+        try fileManager.spt_forceCopyItem(at: headerURL, to: headerArtifactURL)
     }
 
     func includeModuleDefinitionsToTheArtifact(arch: String, moduleURL: URL) throws {

Sources/XCRemoteCache/Artifacts/FileDependenciesRemapper.swift

@@ -0,0 +1,81 @@
+// 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.
+
+import Foundation
+
+
+enum FileDependenciesRemapperError: Error {
+    /// Thrown when the file to remap is invalid (e.g. doesn't exist or has unexpected format)
+    case invalidRemappingFile(URL)
+}
+
+/// Replaces paths in a file content between generic (placeholder-based)
+/// and local formats
+protocol FileDependenciesRemapper {
+    /// Replaces all generic paths (with placeholders) to a local, machine
+    /// specific absolute paths
+    /// - Parameter url: location of a file that should be remapped in-place
+    func remap(fromGeneric url: URL) throws
+    /// Replaces all local, machine specific absolute paths to
+    /// generic ones
+    /// - Parameter url: location of a file that should be remapped in-place
+    func remap(fromLocal url: URL) throws
+}
+
+/// Remaps absolute paths in a text files stored on a disk
+/// Note: That class can be used only for text-based files, not binaries
+class TextFileDependenciesRemapper: FileDependenciesRemapper {
+    private static let linesSeparator = "\n"
+    private let remapper: DependenciesRemapper
+    private let fileAccessor: FileAccessor
+
+    init(remapper: DependenciesRemapper, fileAccessor: FileAccessor) {
+        self.remapper = remapper
+        self.fileAccessor = fileAccessor
+    }
+
+    private func readFileLines(_ url: URL) throws -> [String] {
+        guard let content = try fileAccessor.contents(atPath: url.path) else {
+            // the file is empty
+            return []
+        }
+        guard let contentString = String(data: content, encoding: .utf8) else {
+            throw FileDependenciesRemapperError.invalidRemappingFile(url)
+        }
+        return contentString.components(separatedBy: .newlines)
+    }
+
+    private func storeFileLines(lines: [String], url: URL) throws {
+        let contentString = lines.joined(separator: "\n")
+        let contentData = contentString.data(using: String.Encoding.utf8)
+        try fileAccessor.write(toPath: url.path, contents: contentData)
+    }
+
+    func remap(fromGeneric url: URL) throws {
+        let contentLines = try readFileLines(url)
+        let remappedContent = try remapper.replace(genericPaths: contentLines)
+        try storeFileLines(lines: remappedContent, url: url)
+    }
+
+    func remap(fromLocal url: URL) throws {
+        let contentLines = try readFileLines(url)
+        let remappedContent = try remapper.replace(localPaths: contentLines)
+        try storeFileLines(lines: remappedContent, url: url)
+    }
+}

Sources/XCRemoteCache/Artifacts/SwiftmoduleFileExtension.swift

@@ -31,6 +31,8 @@ enum SwiftmoduleFileExtension: String {
     case swiftdoc
     case swiftsourceinfo
     case swiftinterface
+    case privateSwiftinterface = "private.swiftinterface"
+    case abiJson = "abi.json"
 }
 
 extension SwiftmoduleFileExtension {
@@ -40,5 +42,7 @@ extension SwiftmoduleFileExtension {
         .swiftdoc: .required,
         .swiftsourceinfo: .optional,
         .swiftinterface: .optional,
+        .privateSwiftinterface: .optional,
+        .abiJson: .optional,
     ]
 }

Sources/XCRemoteCache/Commands/Libtool/XCLibtool.swift

@@ -20,7 +20,7 @@
 import Foundation
 
 /// Represents a mode that libtool was called
-public enum XCLibtoolMode {
+public enum XCLibtoolMode: Equatable {
     /// Creating a static library (ar format) from a set of .o input files
     case createLibrary(output: String, filelist: String, dependencyInfo: String)
     /// Creating a universal library (multiple-architectures) from a set of input .a static libraries

Sources/XCRemoteCache/Commands/Libtool/XCLibtoolCreateUniversalBinary.swift

@@ -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")

Sources/XCRemoteCache/Commands/Plugins/Thinning/Factories/ThinningConsumerArtifactsOrganizerFactory.swift

@@ -27,13 +27,19 @@ protocol ThinningConsumerArtifactsOrganizerFactory {
 }
 
 class ThinningConsumerZipArtifactsOrganizerFactory: ThinningConsumerArtifactsOrganizerFactory {
+    private let processors: [ArtifactProcessor]
     private let fileManager: FileManager
 
-    init(fileManager: FileManager) {
+    init(processors: [ArtifactProcessor], fileManager: FileManager) {
+        self.processors = processors
         self.fileManager = fileManager
     }
 
     func build(targetTempDir: URL) -> ArtifactOrganizer {
-        ZipArtifactOrganizer(targetTempDir: targetTempDir, fileManager: fileManager)
+        ZipArtifactOrganizer(
+            targetTempDir: targetTempDir,
+            artifactProcessors: processors,
+            fileManager: fileManager
+        )
     }
 }

Sources/XCRemoteCache/Commands/Plugins/Thinning/ThinningCreatorPlugin.swift

@@ -38,7 +38,7 @@ class ThinningCreatorPlugin: ArtifactCreatorPlugin {
 
     /// 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 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, modeMarkerPath: String, dirScanner: DirScanner) {
         self.targetTempDir = targetTempDir
@@ -94,7 +94,7 @@ class ThinningCreatorPlugin: ArtifactCreatorPlugin {
         // 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.
+        // `$(TARGET_TEMP_DIR)/xccache/{{fileKey}}.zip` location
 
         let targetEnabledMarker = tempDir.appendingPathComponent(modeMarkerPath)
         let targetReusedArtifactRootDir = tempDir.appendingPathComponent("xccache")

Sources/XCRemoteCache/Commands/Plugins/Thinning/ThinningDiskSwiftcProductsGenerator.swift

@@ -58,7 +58,7 @@ class ThinningDiskSwiftcProductsGenerator: SwiftcProductsGenerator {
     func generateFrom(
         artifactSwiftModuleFiles sourceAtifactSwiftModuleFiles: [SwiftmoduleFileExtension: URL],
         artifactSwiftModuleObjCFile: URL
-    ) throws -> URL {
+    ) throws -> SwiftcProductsGeneratorOutput {
         // Move cached -Swift.h file to the expected location
         try diskCopier.copy(file: artifactSwiftModuleObjCFile, destination: objcHeaderOutput)
         for (ext, url) in sourceAtifactSwiftModuleFiles {
@@ -79,6 +79,9 @@ class ThinningDiskSwiftcProductsGenerator: SwiftcProductsGenerator {
         }
 
         // Build parent dir of the .swiftmodule file that contains a module
-        return modulePathOutput.deletingLastPathComponent()
+        return SwiftcProductsGeneratorOutput(
+            swiftmoduleDir: modulePathOutput.deletingLastPathComponent(),
+            objcHeaderFile: objcHeaderOutput
+        )
     }
 }

Sources/XCRemoteCache/Commands/Plugins/Thinning/ThinningPrebuildPlugin.swift

@@ -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 \

Sources/XCRemoteCache/Commands/Plugins/Thinning/UnzippedArtifactSwiftProductsOrganizer.swift

@@ -73,11 +73,12 @@ class UnzippedArtifactSwiftProductsOrganizer: SwiftProductsOrganizer {
             .appendingPathComponent(moduleName)
             .appendingPathComponent("\(moduleName)-Swift.h")
 
-        let generatedModuleDir = try productsGenerator.generateFrom(
+        let generatedModule = try productsGenerator.generateFrom(
             artifactSwiftModuleFiles: artifactSwiftmoduleFiles,
             artifactSwiftModuleObjCFile: artifactSwiftModuleObjCFile
         )
 
-        try fingerprintSyncer.decorate(sourceDir: generatedModuleDir, fingerprint: fingerprint)
+        try fingerprintSyncer.decorate(sourceDir: generatedModule.swiftmoduleDir, fingerprint: fingerprint)
+        try fingerprintSyncer.decorate(file: generatedModule.objcHeaderFile, fingerprint: fingerprint)
     }
 }

Sources/XCRemoteCache/Commands/Postbuild/Postbuild.swift

@@ -238,13 +238,32 @@ class Postbuild {
         let moduleSwiftProductURL = context.productsDir
             .appendingPathComponent(context.modulesFolderPath)
             .appendingPathComponent("\(modulename).swiftmodule")
+        let objcHeaderSwiftProductURL = context.derivedSourcesDir
+            .appendingPathComponent("\(modulename)-Swift.h")
+        // This header is obly valid if building a frameworks
+        let objcHeaderSwiftPublicPathURL = context.publicHeadersFolderPath?
+            .appendingPathComponent("\(modulename)-Swift.h")
         if let fingerprint = contextSpecificFingerprint {
             try fingerprintSyncer.decorate(
                 sourceDir: moduleSwiftProductURL,
                 fingerprint: fingerprint
             )
+            try fingerprintSyncer.decorate(
+                file: objcHeaderSwiftProductURL,
+                fingerprint: fingerprint
+            )
+            if let objcPublic = objcHeaderSwiftPublicPathURL {
+                try fingerprintSyncer.decorate(
+                    file: objcPublic,
+                    fingerprint: fingerprint
+                )
+            }
         } else {
             try fingerprintSyncer.delete(sourceDir: moduleSwiftProductURL)
+            try fingerprintSyncer.delete(sourceDir: objcHeaderSwiftProductURL)
+            if let objcPublic = objcHeaderSwiftPublicPathURL {
+                try fingerprintSyncer.delete(file: objcPublic)
+            }
         }
     }
 }

Sources/XCRemoteCache/Commands/Postbuild/PostbuildContext.swift

@@ -40,6 +40,7 @@ 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
@@ -73,22 +74,29 @@ public struct PostbuildContext {
     let builtProductsDir: URL
     /// Location to the product bundle. Can be nil for libraries
     let bundleDir: URL?
-    let derivedSourcesDir: URL
+    var 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)
+    /// 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]
+    /// Location of public headers. Not always available (e.g. static libraries)
+    var publicHeadersFolderPath: URL?
 }
 
 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")
+        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
@@ -119,7 +127,7 @@ 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
@@ -131,5 +139,12 @@ extension PostbuildContext {
         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
+        let publicHeadersPathEnv: String? = env.readEnv(key: "PUBLIC_HEADERS_FOLDER_PATH")
+        if let publicHeadersPath = publicHeadersPathEnv, publicHeadersPathEnv != "/usr/local/include" {
+            // '/usr/local/include' is a value of PUBLIC_HEADERS_FOLDER_PATH when no public headers are automatically
+            // generated and it is up to a project configuration to place it in a common location (e.g. static library)
+            publicHeadersFolderPath = builtProductsDir.appendingPathComponent(publicHeadersPath)
+        }
     }
 }

Sources/XCRemoteCache/Commands/Postbuild/XCPostbuild.swift

@@ -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)
             }
@@ -66,8 +68,8 @@ 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 envsRemapper = try StringDependenciesRemapperFactory().build(
-                orderKeys: DependenciesMapping.rewrittenEnvs,
+            let envsRemapper = try PathDependenciesRemapperFactory().build(
+                orderKeys: DependenciesMapping.rewrittenEnvs + config.customRewriteEnvs,
                 envs: env,
                 customMappings: config.outOfBandMappings
             )
@@ -85,8 +87,14 @@ public class XCPostbuild {
                 fingerprintFilesGenerator,
                 algorithm: MD5Algorithm()
             )
-            let organizer = ZipArtifactOrganizer(targetTempDir: context.targetTempDir, fileManager: fileManager)
+            let organizer = ZipArtifactOrganizer(
+                targetTempDir: context.targetTempDir,
+                // In postbuild we don't preprocess artifacts (no need to replace path placeholders)
+                artifactProcessors: [],
+                fileManager: fileManager
+            )
             let metaWriter = JsonMetaWriter(fileWriter: fileManager, pretty: config.prettifyMetaFiles)
+            let fileRemapper = TextFileDependenciesRemapper(remapper: envsRemapper, fileAccessor: fileManager)
             let artifactCreator = BuildArtifactCreator(
                 buildDir: context.productsDir,
                 tempDir: context.targetTempDir,
@@ -95,6 +103,7 @@ public class XCPostbuild {
                 modulesFolderPath: context.modulesFolderPath,
                 dSYMPath: context.dSYMPath,
                 metaWriter: metaWriter,
+                artifactProcessor: UnzippedArtifactProcessor(fileRemapper: fileRemapper, dirScanner: fileManager),
                 fileManager: fileManager
             )
             let dirAccessor = DirAccessorComposer(
@@ -112,6 +121,7 @@ public class XCPostbuild {
                 awsV4Signature = AWSV4Signature(
                     secretKey: config.AWSSecretKey,
                     accessKey: config.AWSAccessKey,
+                    securityToken: config.AWSSecurityToken,
                     region: config.AWSRegion,
                     service: config.AWSService,
                     date: Date(timeIntervalSinceNow: 0)
@@ -120,6 +130,7 @@ public class XCPostbuild {
             let networkClient = NetworkClientImpl(
                 session: sessionFactory.build(),
                 retries: config.uploadRetries,
+                retryDelay: config.retryDelay,
                 fileManager: fileManager,
                 awsV4Signature: awsV4Signature
             )
@@ -127,6 +138,7 @@ public class XCPostbuild {
                 mode: context.mode,
                 downloadStreamURL: context.recommendedCacheAddress,
                 upstreamStreamURL: context.cacheAddresses,
+                uploadBatchSize: config.uploadBatchSize,
                 networkClient: networkClient,
                 urlBuilderFactory: {
                     try URLBuilderImpl(
@@ -149,7 +161,8 @@ public class XCPostbuild {
             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.
+                // captured from the swiftc invocation similarly is stored in the `history.compile`
+                // for the consumer mode
                 let overlayReader = JsonOverlayReader(
                     context.overlayHeadersPath,
                     mode: .bestEffort,
@@ -167,7 +180,9 @@ public class XCPostbuild {
                 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(
@@ -194,7 +209,10 @@ public class XCPostbuild {
                 if context.moduleName == config.thinningTargetModuleName {
                     switch context.mode {
                     case .consumer:
+                        // no need to process artifacts in postbuild. Prebuild has already
+                        // run a processor on a downloaded artifact
                         let artifactOrganizerFactory = ThinningConsumerZipArtifactsOrganizerFactory(
+                            processors: [],
                             fileManager: fileManager
                         )
                         let swiftProductsLocationProvider =
@@ -318,3 +336,4 @@ public class XCPostbuild {
         }
     }
 }
+// swiftlint:enable type_body_length

Sources/XCRemoteCache/Commands/Prebuild/Prebuild.swift

@@ -63,7 +63,9 @@ class Prebuild {
         do {
             let metaData = try networkClient.fetch(.meta(commit: commit))
             let meta = try metaReader.read(data: metaData)
-            let localDependencies = try 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 {

Sources/XCRemoteCache/Commands/Prebuild/PrebuildContext.swift

@@ -43,7 +43,8 @@ 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)
+    /// location of the json file that define virtual files system overlay
+    /// (mappings of the virtual location file -> local file path)
     let overlayHeadersPath: URL
 }
 

Sources/XCRemoteCache/Commands/Prebuild/XCPrebuild.swift

@@ -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
             )
@@ -115,15 +122,15 @@ public class XCPrebuild {
             )
             let client: NetworkClient = config.disableHttpCache ? networkClient : cacheNetworkClient
             let remoteNetworkClient = RemoteNetworkClientImpl(client, urlBuilder)
-            let envsRemapper = try StringDependenciesRemapperFactory().build(
-                orderKeys: DependenciesMapping.rewrittenEnvs,
+            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.
+                // do not fail in case of a missing headers overlay file
                 let overlayReader = JsonOverlayReader(
                     context.overlayHeadersPath,
                     mode: .bestEffort,
@@ -145,9 +152,14 @@ public class XCPrebuild {
                 filesFingerprintGenerator,
                 algorithm: MD5Algorithm()
             )
-            let organizer = ZipArtifactOrganizer(targetTempDir: context.targetTempDir, fileManager: fileManager)
-            let compilationHistoryOrganizer = CompilationHistoryFileOrganizer(
-                context.compilationHistoryFile,
+            let fileRemapper = TextFileDependenciesRemapper(
+                remapper: envsRemapper,
+                fileAccessor: fileManager
+            )
+            let artifactProcessor = UnzippedArtifactProcessor(fileRemapper: fileRemapper, dirScanner: fileManager)
+            let organizer = ZipArtifactOrganizer(
+                targetTempDir: context.targetTempDir,
+                artifactProcessors: [artifactProcessor],
                 fileManager: fileManager
             )
             let metaReader = JsonMetaReader(fileAccessor: fileManager)
@@ -155,7 +167,10 @@ public class XCPrebuild {
 
             if config.thinningEnabled {
                 if context.moduleName == config.thinningTargetModuleName, let thinnedTarget = context.thinnedTargets {
-                    let organizerFactory = ThinningConsumerZipArtifactsOrganizerFactory(fileManager: .default)
+                    let organizerFactory = ThinningConsumerZipArtifactsOrganizerFactory(
+                        processors: [artifactProcessor],
+                        fileManager: fileManager
+                    )
                     let aggregationPlugin = ThinningConsumerPrebuildPlugin(
                         targetName: context.targetName,
                         tempDir: context.targetTempDir,
@@ -187,7 +202,6 @@ 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(
@@ -195,6 +209,7 @@ public class XCPrebuild {
                 errorMessage: "Prebuild step failed with error: \(error)"
             )
         }
+        compilationHistoryOrganizer.reset()
     }
 
     private func disableRemoteCache(modeController: PhaseCacheModeController, errorMessage: String?) {

Sources/XCRemoteCache/Commands/Prepare/CCWrapperBuilder.swift

@@ -72,7 +72,17 @@ class TemplateBasedCCWrapperBuilder: CCWrapperBuilder {
         )
         infoLog("ClangWrapperBuilder compiles file at \(compilationFile).")
         // -O3: optimize for faster execution
-        let args = [clangCommand, "-arch", "arm64", "-arch", "x86_64", "-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)")
     }
@@ -385,6 +395,9 @@ 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_objc_header_arg_value = "objective-c-header";
+            const char *precompile_c_header_arg_value = "c-header";
             const char *clang_cmd = "\(clangCommand)";
             const char *markerFile = "\(markerFilename)";
             const char *compilationHistoryFile = "\(compilationHistoryFilename)";
@@ -399,6 +412,7 @@ 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) ) {
@@ -419,6 +433,12 @@ 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") ||
@@ -426,10 +446,13 @@ 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 {
@@ -438,6 +461,14 @@ 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_objc_header_arg_value) == 0 || strcmp(language_mode, precompile_c_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);
@@ -508,8 +539,6 @@ 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

Sources/XCRemoteCache/Commands/Prepare/Integrate/BuildSettingsIntegrateAppender.swift

@@ -33,20 +33,24 @@ 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
             result["LD"] = wrappers.ld.path
             result["LIBTOOL"] = wrappers.libtool.path
+            result["LDPLUSPLUS"] = wrappers.ldplusplus.path
         }
 
         let existingSwiftFlags = result["OTHER_SWIFT_FLAGS"] as? String
@@ -61,8 +65,11 @@ 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_PLATFORM_PREFERRED_ARCH"] = "$(LINK_FILE_LIST_$(CURRENT_VARIANT)_$(PLATFORM_PREFERRED_ARCH):dir:standardizepath:file:default=arm64)"
+        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
     }
 }

Sources/XCRemoteCache/Commands/Prepare/Integrate/IncludeOracle.swift

@@ -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
         }

Sources/XCRemoteCache/Commands/Prepare/Integrate/IntegrateContext.swift

@@ -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")
         )

Sources/XCRemoteCache/Commands/Prepare/Integrate/XCIntegrate.swift

@@ -74,7 +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(
@@ -97,7 +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 {

Sources/XCRemoteCache/Commands/Prepare/Integrate/XCRCBinariesPaths.swift

@@ -26,6 +26,7 @@ struct XCRCBinariesPaths {
     let swiftc: URL
     let libtool: URL
     let ld: URL
+    let ldplusplus: URL
     let prebuild: URL
     let postbuild: URL
 }

Sources/XCRemoteCache/Commands/Prepare/Integrate/XcodeProjIntegrate.swift

@@ -230,10 +230,12 @@ struct XcodeProjIntegrate: Integrate {
         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)
+            // 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.insert(postbuildPhase, at: sourceIndex + 1)
             pbxproj.add(object: prebuildPhase)
             target.buildPhases.insert(prebuildPhase, at: sourceIndex)
-            pbxproj.add(object: postbuildPhase)
-            target.buildPhases.append(postbuildPhase)
         }
     }
 

Sources/XCRemoteCache/Commands/Prepare/XCConfig.swift

@@ -32,7 +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)")
         }

Sources/XCRemoteCache/Commands/Prepare/XCPrepare.swift

@@ -61,7 +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 {
@@ -78,6 +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)
@@ -86,6 +87,7 @@ public class XCPrepare {
             let networkClient = NetworkClientImpl(
                 session: sessionFactory.build(),
                 retries: config.downloadRetries,
+                retryDelay: config.retryDelay,
                 fileManager: fileManager,
                 awsV4Signature: awsV4Signature
             )

Sources/XCRemoteCache/Commands/Prepare/XCPrepareMark.swift

@@ -46,7 +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 {
@@ -60,6 +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)
@@ -68,6 +69,7 @@ public class XCPrepareMark {
             let networkClient = NetworkClientImpl(
                 session: sessionFactory.build(),
                 retries: config.uploadRetries,
+                retryDelay: config.retryDelay,
                 fileManager: fileManager,
                 awsV4Signature: awsV4Signature
             )
@@ -75,6 +77,7 @@ public class XCPrepareMark {
                 mode: .producer,
                 downloadStreamURL: context.recommendedCacheAddress,
                 upstreamStreamURL: context.cacheAddresses,
+                uploadBatchSize: config.uploadBatchSize,
                 networkClient: networkClient
             ) { [configuration, platform] cacheAddress in
                 // Prepare URLs don't include target name or envFingperint, which are valid only for a target level

Sources/XCRemoteCache/Commands/Prepare/XCStats.swift

@@ -36,7 +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)")

Sources/XCRemoteCache/Commands/ProductBinaryCreator/XCCreateBinary.swift

@@ -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)")
@@ -78,7 +78,12 @@ public class XCCreateBinary {
         }
         let markerURL = tempDir.appendingPathComponent(config.modeMarkerPath)
         do {
-            let organizer = ZipArtifactOrganizer(targetTempDir: tempDir, fileManager: fileManager)
+            let organizer = ZipArtifactOrganizer(
+                targetTempDir: tempDir,
+                // Creation binary doesn't call artifact preprocessing
+                artifactProcessors: [],
+                fileManager: fileManager
+            )
             let dependenciesWriter = FileDatWriter(dependencyInfo, fileManager: fileManager)
             let markerReader = FileMarkerReader(markerURL, fileManager: fileManager)
             guard fileManager.fileExists(atPath: markerURL.path) else {

Sources/XCRemoteCache/Commands/Swiftc/MirroredLinkingSwiftcProductsGenerator.swift

@@ -55,7 +55,7 @@ class MirroredLinkingSwiftcProductsGenerator: SwiftcProductsGenerator {
     func generateFrom(
         artifactSwiftModuleFiles: [SwiftmoduleFileExtension: URL],
         artifactSwiftModuleObjCFile: URL
-    ) throws -> URL {
+    ) throws -> SwiftcProductsGeneratorOutput {
         /// Predict moduleName from the `*.swiftmodule` artifact
         let foundSwiftmoduleFile = artifactSwiftModuleFiles[.swiftmodule]
         guard let mainSwiftmoduleFile = foundSwiftmoduleFile else {

Sources/XCRemoteCache/Commands/Swiftc/SwiftcOrchestrator.swift

@@ -110,8 +110,8 @@ 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:

Sources/XCRemoteCache/Commands/Swiftc/SwiftcProductsGenerator.swift

@@ -20,20 +20,25 @@
 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
 }
 
+struct SwiftcProductsGeneratorOutput {
+    let swiftmoduleDir: URL
+    let objcHeaderFile: URL
+}
+
 /// Generates swiftc product to the expected location
 protocol SwiftcProductsGenerator {
     /// Generates products from given files
-    /// - Returns: location dir where .swiftmodule files have been placed
+    /// - Returns: location dir where .swiftmodule and ObjC header files have been placed
     func generateFrom(
         artifactSwiftModuleFiles: [SwiftmoduleFileExtension: URL],
         artifactSwiftModuleObjCFile: URL
-    ) throws -> URL
+    ) throws -> SwiftcProductsGeneratorOutput
 }
 
 /// Generator that produces all products in the locations where Xcode expects it, using provided disk copier
@@ -64,7 +69,7 @@ class DiskSwiftcProductsGenerator: SwiftcProductsGenerator {
     func generateFrom(
         artifactSwiftModuleFiles sourceAtifactSwiftModuleFiles: [SwiftmoduleFileExtension: URL],
         artifactSwiftModuleObjCFile: URL
-    ) throws -> URL {
+    ) throws -> SwiftcProductsGeneratorOutput {
         // Move cached -Swift.h file to the expected location
         try diskCopier.copy(file: artifactSwiftModuleObjCFile, destination: objcHeaderOutput)
         for (ext, url) in sourceAtifactSwiftModuleFiles {
@@ -85,6 +90,9 @@ class DiskSwiftcProductsGenerator: SwiftcProductsGenerator {
         }
 
         // Build parent dir of the .swiftmodule file that contains a module
-        return modulePathOutput.deletingLastPathComponent()
+        return SwiftcProductsGeneratorOutput(
+            swiftmoduleDir: modulePathOutput.deletingLastPathComponent(),
+            objcHeaderFile: objcHeaderOutput
+        )
     }
 }

Sources/XCRemoteCache/Commands/Swiftc/XCSwiftc.swift

@@ -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 {
@@ -83,7 +83,12 @@ public class XCSwiftc {
 
         let inputReader = SwiftcFilemapInputEditor(context.filemap, fileManager: fileManager)
         let fileListEditor = FileListEditor(context.fileList, fileManager: fileManager)
-        let artifactOrganizer = ZipArtifactOrganizer(targetTempDir: context.tempDir, fileManager: fileManager)
+        let artifactOrganizer = ZipArtifactOrganizer(
+            targetTempDir: context.tempDir,
+            // xcswiftc  doesn't call artifact preprocessing
+            artifactProcessors: [],
+            fileManager: fileManager
+        )
         // TODO: check for allowedFile comparing a list of all inputfiles, not dependencies from a marker
         let makerReferencedFilesListScanner = FileListScannerImpl(markerReader, caseSensitive: false)
         let allowedFilesListScanner = ExceptionsFilteredFileListScanner(

Sources/XCRemoteCache/Config/XCRemoteCacheConfig.swift

@@ -83,6 +83,10 @@ 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
+    /// Maximum number of simultaneous requests. 0 means no limits
+    var uploadBatchSize: Int = 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
@@ -95,10 +99,10 @@ public struct XCRemoteCacheConfig: Encodable {
     ///  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 e
-    /// xecuted if a target switches to local compilation.
+    /// 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.
+    /// 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
@@ -107,7 +111,8 @@ public struct XCRemoteCacheConfig: Encodable {
     var turnOffRemoteCacheOnFirstTimeout: Bool = false
     /// 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
-    var productFilesExtensionsWithContentOverride = ["swiftmodule"]
+    /// .h files may contain absolute paths if NS_ENUM is used in a public API from Swift code
+    var productFilesExtensionsWithContentOverride = ["swiftmodule", "h"]
     /// If true, plugins for thinning support should be enabled
     var thinningEnabled: Bool = false
     /// Module name of a target that works as a helper for thinned targets
@@ -118,21 +123,31 @@ public struct XCRemoteCacheConfig: Encodable {
     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.
+    /// 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.
+    /// `/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 {
@@ -165,6 +180,8 @@ extension XCRemoteCacheConfig {
         merge.statsDir = scheme.statsDir ?? statsDir
         merge.downloadRetries = scheme.downloadRetries ?? downloadRetries
         merge.uploadRetries = scheme.uploadRetries ?? uploadRetries
+        merge.retryDelay = scheme.retryDelay ?? retryDelay
+        merge.uploadBatchSize = scheme.uploadBatchSize ?? uploadBatchSize
         merge.requestCustomHeaders = scheme.requestCustomHeaders ?? requestCustomHeaders
         merge.thinTargetMockFilename = scheme.thinTargetMockFilename ?? thinTargetMockFilename
         merge.focusedTargets = scheme.focusedTargets ?? focusedTargets
@@ -181,11 +198,14 @@ extension XCRemoteCacheConfig {
         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
     }
 
@@ -230,6 +250,8 @@ struct ConfigFileScheme: Decodable {
     let statsDir: String?
     let downloadRetries: Int?
     let uploadRetries: Int?
+    let retryDelay: Double?
+    let uploadBatchSize: Int?
     let requestCustomHeaders: [String: String]?
     let thinTargetMockFilename: String?
     let focusedTargets: [String]?
@@ -243,11 +265,14 @@ struct ConfigFileScheme: Decodable {
     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 {
@@ -275,6 +300,8 @@ struct ConfigFileScheme: Decodable {
         case statsDir = "stats_dir"
         case downloadRetries = "download_retries"
         case uploadRetries = "upload_retries"
+        case retryDelay = "retry_delay"
+        case uploadBatchSize = "upload_batch_size"
         case requestCustomHeaders = "request_custom_headers"
         case thinTargetMockFilename = "thin_target_mock_filename"
         case focusedTargets = "focused_targets"
@@ -288,11 +315,14 @@ struct ConfigFileScheme: Decodable {
         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"
     }
 }
 
@@ -305,31 +335,42 @@ 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()
@@ -337,7 +378,7 @@ 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)
         }

Sources/XCRemoteCache/Dependencies/DependenciesReader.swift

@@ -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
     }
 }

Sources/XCRemoteCache/Dependencies/DependenciesWriter.swift

@@ -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)

Sources/XCRemoteCache/Dependencies/DependencyProcessor.swift

@@ -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?) {
+    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] {
@@ -73,10 +80,14 @@ class DependencyProcessorImpl: DependencyProcessor {
     private func classify(_ files: [URL]) -> [Dependency] {
         return files.map { file -> Dependency in
             let filePath = file.resolvingSymlinksInPath().path
-            if filePath.hasPrefix(xcodePath) {
+            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 +118,12 @@ 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)
     }
 }

Sources/XCRemoteCache/Dependencies/FingerprintSyncer.swift

@@ -30,6 +30,10 @@ protocol FingerprintSyncer {
     func decorate(sourceDir: URL, fingerprint: String) throws
     /// Deletes fingerprint overrides in the dir (if already created)
     func delete(sourceDir: URL) throws
+    /// Sets a fingerprint override for a singe file placed
+    func decorate(file: URL, fingerprint: String) throws
+    /// Deletes fingerprint override for a file  (if already created)
+    func delete(file: URL) throws
 }
 
 class FileFingerprintSyncer: FingerprintSyncer {
@@ -78,4 +82,25 @@ class FileFingerprintSyncer: FingerprintSyncer {
             try dirAccessor.removeItem(atPath: file.path)
         }
     }
+
+    func decorate(file: URL, fingerprint: String) throws {
+        guard let fingerprintData = fingerprint.data(using: .utf8) else {
+            throw FingerprintSyncerError.invalidFingerprint
+        }
+        let fingerprintFile = file.appendingPathExtension(fingerprintExtension)
+        try dirAccessor.write(toPath: fingerprintFile.path, contents: fingerprintData)
+    }
+
+    func delete(file: URL) throws {
+        guard case .file = try dirAccessor.itemType(atPath: file.path) else {
+            // no file to decorate (no module was generated)
+            return
+        }
+        let overrideURL = file.appendingPathExtension(fingerprintExtension)
+        guard case .file = try dirAccessor.itemType(atPath: overrideURL.path) else {
+            // no override
+            return
+        }
+        try dirAccessor.removeItem(atPath: overrideURL.path)
+    }
 }

Sources/XCRemoteCache/Dependencies/OverlayDependenciesRemapper.swift

@@ -42,8 +42,8 @@ class OverlayDependenciesRemapper: DependenciesRemapper {
 
     private func mapPath(
         _ path: String,
-        source: KeyPath<OverlayMapping,URL>,
-        destination: KeyPath<OverlayMapping,URL>
+        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

Sources/XCRemoteCache/Dependencies/OverlayReader.swift

@@ -91,7 +91,7 @@ class JsonOverlayReader: OverlayReader {
             case .strict:
                 throw JsonOverlayReaderError.missingSourceFile(json)
             case .bestEffort:
-                printWarning("overlay mapping file \(json) doesn't exist. Skipping overlay for the best-effort mode.")
+                debugLog("overlay mapping file \(json) doesn't exist. Skipping overlay for the best-effort mode.")
                 return []
             }
         }
@@ -100,7 +100,7 @@ class JsonOverlayReader: OverlayReader {
             let mappings: [OverlayMapping] = try overlay.roots.reduce([]) { prev, root in
                 switch root.type {
                 case .directory:
-                    //iterate all contents
+                    // iterate all contents
                     let dir = URL(fileURLWithPath: root.name)
                     let mappings: [OverlayMapping] = try root.contents.map { content in
                         switch content.type {
@@ -124,7 +124,7 @@ class JsonOverlayReader: OverlayReader {
             case .strict:
                 throw error
             case .bestEffort:
-                printWarning("Overlay reader has failed with an error \(error). Best-effort mode - skipping an overlay.")
+                errorLog("Overlay reader has failed with an error \(error). Best-effort mode - skipping an overlay.")
                 return []
             }
         }

Sources/XCRemoteCache/Dependencies/PathDependenciesRemapperFactory.swift

@@ -19,24 +19,28 @@
 
 import Foundation
 
-enum StringDependenciesRemapperFactoryError: Error {
+enum PathDependenciesRemapperFactoryError: Error {
     /// Remapping keys are duplicated and can lead to undetermined results
     case mappingKeyDuplication
 }
 
-class StringDependenciesRemapperFactory {
+class PathDependenciesRemapperFactory {
     func build(
         orderKeys: [String],
         envs: [String: String],
         customMappings: [String: String]
     ) throws -> StringDependenciesRemapper {
-        let mappingMap = try envs.merging(customMappings) { envValue, outOfBandMapping in
-            throw StringDependenciesRemapperFactoryError.mappingKeyDuplication
+        let mappingMap = try envs.merging(customMappings) { _, _ in
+            throw PathDependenciesRemapperFactoryError.mappingKeyDuplication
         }
-        let mappingOrderKeys =  orderKeys + customMappings.keys
-        let mappings: [StringDependenciesRemapper.Mapping] = try mappingOrderKeys.map { key in
-            let localValue: String = try mappingMap.readEnv(key: key)
-            return StringDependenciesRemapper.Mapping(generic: "$(\(key))", local: localValue)
+        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)
     }

Sources/XCRemoteCache/Dependencies/TargetDepdenciesReader.swift

@@ -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"

Sources/XCRemoteCache/FileAccess/DirAccessor.swift

@@ -33,8 +33,13 @@ protocol DirScanner {
 
     /// Returns all items in a directory (shallow search)
     /// - Parameter at: url of an existing directory to search
-    /// - Throws: an error if dir doesn't exist or I/O error
+    /// - Throws: an error if a dir doesn't exist or on I/O error
     func items(at dir: URL) throws -> [URL]
+
+    /// Returns all items in a directory (recursive search)
+    /// - Parameter at: url of an existing directory to search
+    /// - Throws: an error if a dir doesn't exist or on I/O error
+    func recursiveItems(at dir: URL) throws -> [URL]
 }
 
 typealias DirAccessor = FileAccessor & DirScanner
@@ -54,4 +59,18 @@ extension FileManager: DirScanner {
         let resolvedDir = dir.resolvingSymlinksInPath()
         return try contentsOfDirectory(at: resolvedDir, includingPropertiesForKeys: nil, options: [])
     }
+
+    func recursiveItems(at dir: URL) throws -> [URL] {
+        // Iterating DFS
+        var queue: [URL] = [dir]
+        var results: [URL] = []
+        while let item = queue.popLast() {
+            if try itemType(atPath: item.path) == .dir {
+                try queue.append(contentsOf: items(at: item))
+            } else {
+                results.append(item)
+            }
+        }
+        return results
+    }
 }

Sources/XCRemoteCache/FileAccess/DirAccessorComposer.swift

@@ -52,4 +52,8 @@ class DirAccessorComposer: DirAccessor {
     func items(at dir: URL) throws -> [URL] {
         try dirScanner.items(at: dir)
     }
+
+    func recursiveItems(at dir: URL) throws -> [URL] {
+        try dirScanner.recursiveItems(at: dir)
+    }
 }

Sources/XCRemoteCache/Fingerprint/EnvironmentFingerprint.swift

@@ -31,7 +31,7 @@ class EnvironmentFingerprintGenerator {
         "DYLIB_COMPATIBILITY_VERSION",
         "DYLIB_CURRENT_VERSION",
         "PRODUCT_MODULE_NAME",
-        "ARCHS"
+        "ARCHS",
     ]
     private let version: String
     private let customFingerprintEnvs: [String]
@@ -52,7 +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

Sources/XCRemoteCache/Logger/Logger.swift

@@ -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)) "
+}

Sources/XCRemoteCache/Models/MetaWriter.swift

@@ -20,7 +20,7 @@
 import Foundation
 
 protocol MetaWriter {
-    func write<T>(_ meta: T, locationDir : URL) throws -> URL where T : Meta
+    func write<T>(_ meta: T, locationDir: URL) throws -> URL where T: Meta
 }
 
 class JsonMetaWriter: MetaWriter {
@@ -36,7 +36,7 @@ class JsonMetaWriter: MetaWriter {
         self.metaEncoder = encoder
     }
 
-    func write<T>(_ meta: T, locationDir : URL) throws -> URL where T : Meta {
+    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)

Sources/XCRemoteCache/Network/Authentication/AWSV4Signature.swift

@@ -23,17 +23,21 @@ 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,

Sources/XCRemoteCache/Network/IgnoringCertificatesTrustManager.swift

@@ -25,7 +25,7 @@ final class IgnoringCertificatesTrustManager: NSObject, URLSessionDelegate {
             completionHandler(.performDefaultHandling, nil)
             return
         }
-        
+
         let urlCredential = URLCredential(trust: serverTrust)
         completionHandler(.useCredential, urlCredential)
     }

Sources/XCRemoteCache/Network/NetworkClientImpl.swift

@@ -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
     }
 
@@ -75,7 +77,12 @@ class NetworkClientImpl: NetworkClient {
     func download(_ url: URL, to location: URL, completion: @escaping (Result<Void, NetworkClientError>) -> Void) {
         var request = URLRequest(url: url)
         setupAuthenticationSignatureIfPresent(&request)
-        makeDownloadRequest(request, output: location, completion: completion)
+        makeDownloadRequest(
+            request,
+            output: location,
+            retries: maxRetries,
+            completion: completion
+        )
     }
 
     func upload(_ file: URL, as url: URL, completion: @escaping (Result<Void, NetworkClientError>) -> Void) {
@@ -123,7 +130,7 @@ class NetworkClientImpl: NetworkClient {
         dataTask.resume()
     }
 
-    private func makeDownloadRequest(_ request: URLRequest, output: URL, completion: @escaping (Result<Void, NetworkClientError>) -> Void) {
+    private func makeDownloadRequest(_ request: URLRequest, output: URL, retries: Int, completion: @escaping (Result<Void, NetworkClientError>) -> Void) {
         guard fileManager.fileExists(atPath: output.path) == false else {
             infoLog("Download file found in the destination, skipping download.")
             completion(.success(()))
@@ -133,6 +140,17 @@ class NetworkClientImpl: NetworkClient {
         let dataTask = session.downloadTask(with: request) { [fileManager] fileURL, _, error in
             guard let fileURL = fileURL else {
                 let networkError = error.map(NetworkClientError.build) ?? .inconsistentSession
+                if retries > 0 {
+                    infoLog("Download request failed with \(networkError). Left retries: \(retries).")
+                    self.retryDownload(
+                        request,
+                        output: output,
+                        retries: retries,
+                        completion: completion,
+                        after: self.retryDelay
+                    )
+                    return
+                }
                 errorLog("Download request failed: \(networkError)")
                 completion(.failure(networkError))
                 return
@@ -173,7 +191,13 @@ 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 +208,30 @@ 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 func retryDownload(_ request: URLRequest, output: 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.makeDownloadRequest(
+                request,
+                output: output,
+                retries: retries - 1,
+                completion: completion
+            )
+        }
+    }
 }
 
 private extension NetworkClientError {

Sources/XCRemoteCache/Network/RemoteNetworkClientAbstractFactory.swift

@@ -27,11 +27,20 @@ class RemoteNetworkClientAbstractFactory {
     private let upstreamStreamURL: [URL]
     private let networkClient: NetworkClient
     private let urlBuilderFactory: (URL) throws -> URLBuilder
+    private let uploadBatchSize: Int
 
-    init(mode: Mode, downloadStreamURL: URL, upstreamStreamURL: [URL], networkClient: NetworkClient, urlBuilderFactory: @escaping (URL) throws -> URLBuilder) {
+    init(
+        mode: Mode,
+        downloadStreamURL: URL,
+        upstreamStreamURL: [URL],
+        uploadBatchSize: Int,
+        networkClient: NetworkClient,
+        urlBuilderFactory: @escaping (URL) throws -> URLBuilder
+    ) {
         self.mode = mode
         self.downloadStreamURL = downloadStreamURL
         self.upstreamStreamURL = upstreamStreamURL
+        self.uploadBatchSize = uploadBatchSize
         self.networkClient = networkClient
         self.urlBuilderFactory = urlBuilderFactory
     }
@@ -49,7 +58,8 @@ class RemoteNetworkClientAbstractFactory {
             return ReplicatedRemotesNetworkClient(
                 networkClient,
                 download: downloadURLBuilder,
-                uploads: upstreamBuilders
+                uploads: upstreamBuilders,
+                uploadBatchSize: uploadBatchSize
             )
         case .consumer:
             return RemoteNetworkClientImpl(networkClient, downloadURLBuilder)

Sources/XCRemoteCache/Network/ReplicatedRemotesNetworkClient.swift

@@ -23,10 +23,12 @@ import Foundation
 class ReplicatedRemotesNetworkClient: RemoteNetworkClientImpl {
     private let networkClient: NetworkClient
     private let uploadURLBuilders: [URLBuilder]
+    private let uploadBatchSize: Int
 
-    init(_ networkClient: NetworkClient, download: URLBuilder, uploads uploadURLBuilders: [URLBuilder]) {
+    init(_ networkClient: NetworkClient, download: URLBuilder, uploads uploadURLBuilders: [URLBuilder], uploadBatchSize: Int) {
         self.networkClient = networkClient
         self.uploadURLBuilders = uploadURLBuilders
+        self.uploadBatchSize = uploadBatchSize
         super.init(networkClient, download)
     }
 
@@ -39,6 +41,9 @@ class ReplicatedRemotesNetworkClient: RemoteNetworkClientImpl {
         let group = DispatchGroup()
         var results: [Result<Void, NetworkClientError>] = Array(repeating: .failure(.noResponse), count: urls.count)
         urls.enumerated().forEach { index, url in
+            if uploadBatchSize > 0 && index > 0 && index % uploadBatchSize == 0 {
+                group.wait()
+            }
             group.enter()
             networkClient.upload(file, as: url) { receivedResult in
                 results[index] = receivedResult
@@ -58,6 +63,9 @@ class ReplicatedRemotesNetworkClient: RemoteNetworkClientImpl {
         let group = DispatchGroup()
         var results: [Result<Void, NetworkClientError>] = Array(repeating: .failure(.noResponse), count: urls.count)
         urls.enumerated().forEach { index, url in
+            if uploadBatchSize > 0 && index > 0 && index % uploadBatchSize == 0 {
+                group.wait()
+            }
             group.enter()
             networkClient.create(url) { receivedResult in
                 results[index] = receivedResult

Sources/XCRemoteCache/Network/URLSessionFactory.swift

@@ -36,6 +36,8 @@ class DefaultURLSessionFactory: URLSessionFactory {
         let configuration = URLSessionConfiguration.default
         configuration.httpAdditionalHeaders = config.requestCustomHeaders
         configuration.timeoutIntervalForRequest = config.timeoutResponseDataChunksInterval
+        configuration.urlCache?.memoryCapacity = 0
+        configuration.urlCache?.diskCapacity = 0
         switch config.disableCertificateVerification {
         case true:
             return URLSession(

Sources/XCRemoteCache/Stats/ExclusiveFileAccessor.swift

@@ -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
         }

Sources/XCRemoteCache/Utils/ENVReader.swift

@@ -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

Sources/xcld/XCLDMain.swift

@@ -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)
         }
 
 

Sources/xcldplusplus/XCLDPlusPlus.swift

@@ -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()
+    }
+}

Sources/xcldplusplus/main.swift

@@ -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()

Sources/xclibtool/XCLibtoolMain.swift

@@ -18,53 +18,24 @@
 // under the License.
 
 import Foundation
+import xclibtoolSupport
 import XCRemoteCache
 
+public enum XCLibtoolMainError: Error {
+    case missingOutput
+    case unsupportedMode
+}
+
 /// Wrapper for a `libtool` program that copies the build executable (e.g. .a) from a cached-downloaded location
 /// Fallbacks to a standard `libtool` when the Ramote cache is not applicable (e.g. modified sources)
 public class XCLibtoolMain {
+    public init() { }
+
     public func main() {
         let args = ProcessInfo().arguments
-        var output: String?
-        // all input arguments library '.a'. Used to create an universal binary
-        var inputLibraries: [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":
-                dependencyInfo = args[i + 1]
-                i += 1
-            case let input where input.hasSuffix(".a"):
-                inputLibraries.append(input)
-            default:
-                break
-            }
-            i += 1
-        }
-        guard let outputInput = output else {
-            exit(1, "Missing 'output' argument. Args: \(args)")
-        }
 
-        let mode: XCLibtoolMode
-        if let filelistInput = filelist, let dependencyInfoInput = dependencyInfo {
-            // libtool is creating a library
-            mode = .createLibrary(output: outputInput, filelist: filelistInput, dependencyInfo: dependencyInfoInput)
-        } else if !inputLibraries.isEmpty {
-            // multiple input libraries suggest creating an universal binary
-            mode = .createUniversalBinary(output: outputInput, inputs: inputLibraries)
-        } else {
-            // unknown mode
-            exit(1, "Unsupported mode. Args: \(args)")
-        }
         do {
+            let mode = try XCLibtoolHelper.buildMode(args: args)
             try XCLibtool(mode).run()
         } catch {
             exit(1, "Failed with: \(error). Args: \(args)")

Sources/xclibtoolSupport/XCLibtoolHelper.swift

@@ -0,0 +1,72 @@
+// Copyright (c) 2023 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
+
+public enum XCLibtoolHelperError: Error {
+    case missingOutput
+    case unsupportedMode
+}
+
+public class XCLibtoolHelper {
+    public static func buildMode(args: [String]) throws -> XCLibtoolMode {
+        var output: String?
+        // all input arguments are '*.a' or no path extension. Used to create an universal binary
+        var inputLibraries: [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":
+                dependencyInfo = args[i + 1]
+                i += 1
+            case let input where ["", "a"].contains(URL(string: args[i])?.pathExtension):
+                // Support for static frameworks (no extension) and static libraries (.a)
+                inputLibraries.append(input)
+            default:
+                break
+            }
+            i += 1
+        }
+        guard let outputInput = output else {
+            throw XCLibtoolHelperError.missingOutput
+        }
+
+        let mode: XCLibtoolMode
+        if let filelistInput = filelist, let dependencyInfoInput = dependencyInfo {
+            // libtool is creating a library
+            mode = .createLibrary(output: outputInput, filelist: filelistInput, dependencyInfo: dependencyInfoInput)
+        } else if !inputLibraries.isEmpty {
+            // multiple input libraries suggest creating an universal binary
+            mode = .createUniversalBinary(output: outputInput, inputs: inputLibraries)
+        } else {
+            // unknown mode
+            throw XCLibtoolHelperError.unsupportedMode
+        }
+        return mode
+    }
+}

Sources/xcswiftc/XCSwiftcMain.swift

@@ -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,

Tests/XCRemoteCacheTests/Artifacts/ArtifactSwiftProductsBuilderImplTests.swift

@@ -28,6 +28,8 @@ class ArtifactSwiftProductsBuilderImplTests: FileXCTestCase {
     private var swiftmoduleDocFile: URL!
     private var swiftmoduleSourceInfoFile: URL!
     private var swiftmoduleInterfaceFile: URL!
+    private var privateSwiftmoduleInterfaceFile: URL!
+    private var abiJsonFile: URL!
     private var workingDir: URL!
     private var builder: ArtifactSwiftProductsBuilderImpl!
 
@@ -39,6 +41,9 @@ class ArtifactSwiftProductsBuilderImplTests: FileXCTestCase {
         swiftmoduleDocFile = moduleDir.appendingPathComponent("MyModule.swiftdoc")
         swiftmoduleSourceInfoFile = moduleDir.appendingPathComponent("MyModule.swiftsourceinfo")
         swiftmoduleInterfaceFile = moduleDir.appendingPathComponent("MyModule.swiftinterface")
+        privateSwiftmoduleInterfaceFile = moduleDir.appendingPathComponent("MyModule.private.swiftinterface")
+        abiJsonFile = moduleDir.appendingPathComponent("MyModule.abi.json")
+
         workingDir = rootDir.appendingPathComponent("working")
         builder = ArtifactSwiftProductsBuilderImpl(
             workingDir: workingDir,
@@ -98,6 +103,8 @@ class ArtifactSwiftProductsBuilderImplTests: FileXCTestCase {
         try fileManager.spt_createEmptyFile(swiftmoduleDocFile)
         try fileManager.spt_createEmptyFile(swiftmoduleSourceInfoFile)
         try fileManager.spt_createEmptyFile(swiftmoduleInterfaceFile)
+        try fileManager.spt_createEmptyFile(privateSwiftmoduleInterfaceFile)
+        try fileManager.spt_createEmptyFile(abiJsonFile)
         let builderSwiftmoduleDir =
             builder
                 .buildingArtifactSwiftModulesLocation()
@@ -110,6 +117,10 @@ class ArtifactSwiftProductsBuilderImplTests: FileXCTestCase {
             builderSwiftmoduleDir.appendingPathComponent("MyModule.swiftsourceinfo")
         let expectedBuildedSwiftInterfaceFile =
             builderSwiftmoduleDir.appendingPathComponent("MyModule.swiftinterface")
+        let expectedPrivateSwiftmoduleInterfaceFile =
+            builderSwiftmoduleDir.appendingPathComponent("MyModule.private.swiftinterface")
+        let expectedAbiJsonFile =
+            builderSwiftmoduleDir.appendingPathComponent("MyModule.abi.json")
 
         try builder.includeModuleDefinitionsToTheArtifact(arch: "arm64", moduleURL: swiftmoduleFile)
 
@@ -117,6 +128,8 @@ class ArtifactSwiftProductsBuilderImplTests: FileXCTestCase {
         XCTAssertTrue(fileManager.fileExists(atPath: expectedBuildedSwiftmoduledocFile.path))
         XCTAssertTrue(fileManager.fileExists(atPath: expectedBuildedSwiftSourceInfoFile.path))
         XCTAssertTrue(fileManager.fileExists(atPath: expectedBuildedSwiftInterfaceFile.path))
+        XCTAssertTrue(fileManager.fileExists(atPath: expectedPrivateSwiftmoduleInterfaceFile.path))
+        XCTAssertTrue(fileManager.fileExists(atPath: expectedAbiJsonFile.path))
     }
 
     func testFailsIncludingWhenMissingRequiredSwiftmoduleFiles() throws {

Tests/XCRemoteCacheTests/Artifacts/BuildArtifactCreatorTests.swift

@@ -32,6 +32,8 @@ class BuildArtifactCreatorTests: FileXCTestCase {
     private var swiftdocURL: URL!
     private var swiftSourceInfoURL: URL!
     private var swiftInterfaceURL: URL!
+    private var privateSwiftInterfaceURL: URL!
+    private var abiJsonURL: URL!
     private var executablePath: String!
     private var executableURL: URL!
     private var creator: BuildArtifactCreator!
@@ -53,11 +55,16 @@ class BuildArtifactCreatorTests: FileXCTestCase {
             .appendingPathComponent("Target.swiftsourceinfo")
         swiftInterfaceURL = workDirectory.appendingPathComponent("Objects-normal")
             .appendingPathComponent("Target.swiftinterface")
+        privateSwiftInterfaceURL = workDirectory.appendingPathComponent("Objects-normal")
+            .appendingPathComponent("Target.private.swiftinterface")
+        abiJsonURL = workDirectory.appendingPathComponent("Objects-normal")
+            .appendingPathComponent("Target.abi.json")
         executablePath = "libTarget.a"
         executableURL = buildDir.appendingPathComponent(executablePath)
         dSYM = executableURL.deletingPathExtension().appendingPathExtension(".dSYM")
         try fileManager.spt_createEmptyFile(executableURL)
         try fileManager.spt_createEmptyFile(headerURL)
+        let artifactProcessor = NoopArtifactProcessor()
 
         creator = BuildArtifactCreator(
             buildDir: buildDir,
@@ -67,6 +74,7 @@ class BuildArtifactCreatorTests: FileXCTestCase {
             modulesFolderPath: "",
             dSYMPath: dSYM,
             metaWriter: JsonMetaWriter(fileWriter: fileManager, pretty: false),
+            artifactProcessor: artifactProcessor,
             fileManager: fileManager
         )
     }
@@ -122,6 +130,8 @@ class BuildArtifactCreatorTests: FileXCTestCase {
         try fileManager.spt_createEmptyFile(swiftdocURL)
         try fileManager.spt_createEmptyFile(swiftSourceInfoURL)
         try fileManager.spt_createEmptyFile(swiftInterfaceURL)
+        try fileManager.spt_createEmptyFile(privateSwiftInterfaceURL)
+        try fileManager.spt_createEmptyFile(abiJsonURL)
 
         try creator.includeModuleDefinitionsToTheArtifact(arch: "arch", moduleURL: swiftmoduleURL)
         let artifact = try creator.createArtifact(artifactKey: "key", meta: sampleMeta)
@@ -136,6 +146,8 @@ class BuildArtifactCreatorTests: FileXCTestCase {
             unzippedURL.appendingPathComponent("swiftmodule/arch/Target.swiftdoc"),
             unzippedURL.appendingPathComponent("swiftmodule/arch/Target.swiftsourceinfo"),
             unzippedURL.appendingPathComponent("swiftmodule/arch/Target.swiftinterface"),
+            unzippedURL.appendingPathComponent("swiftmodule/arch/Target.private.swiftinterface"),
+            unzippedURL.appendingPathComponent("swiftmodule/arch/Target.abi.json"),
         ])
     }
 

Tests/XCRemoteCacheTests/Artifacts/TextFileDependenciesRemapperTests.swift

@@ -0,0 +1,101 @@
+// 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 TextFileDependenciesRemapperTests: FileXCTestCase {
+
+    let stringsRemapper = StringDependenciesRemapper(
+        mappings: [
+            .init(generic: "$(SRCROOT)", local: "/example"),
+        ])
+    let fileAccessor = FileAccessorFake(mode: .strict)
+    var remapper: TextFileDependenciesRemapper!
+
+    override func setUp() {
+        super.setUp()
+        remapper = TextFileDependenciesRemapper(
+            remapper: stringsRemapper,
+            fileAccessor: fileAccessor
+        )
+    }
+
+    func testRemapsGenericPlaceholders() throws {
+        try fileAccessor.write(toPath: "/file", contents: "Some $(SRCROOT).")
+
+        try remapper.remap(fromGeneric: "/file")
+
+        try XCTAssertEqual(fileAccessor.contents(atPath: "/file"), "Some /example.")
+    }
+
+    func testRemapsLocalPathsToPlaceholders() throws {
+        try fileAccessor.write(toPath: "/file", contents: "Some /example.")
+
+        try remapper.remap(fromLocal: "/file")
+
+        try XCTAssertEqual(fileAccessor.contents(atPath: "/file"), "Some $(SRCROOT).")
+    }
+
+    func testPersistsEmptyLines() throws {
+        let multilineData = """
+        Line1
+
+        Line 2
+        """.data(using: .utf8)
+        try fileAccessor.write(toPath: "/file", contents: multilineData)
+
+        try remapper.remap(fromGeneric: "/file")
+
+        try XCTAssertEqual(fileAccessor.contents(atPath: "/file"), multilineData)
+    }
+
+    func testPersistsEmptyLineAtTheEnd() throws {
+        // swiftlint:disable trailing_whitespace
+        let multilineData = """
+        Line1
+
+        Line 2
+
+        """.data(using: .utf8)
+        // swiftlint:enable trailing_whitespace
+        try fileAccessor.write(toPath: "/file", contents: multilineData)
+
+        try remapper.remap(fromGeneric: "/file")
+
+        try XCTAssertEqual(fileAccessor.contents(atPath: "/file"), multilineData)
+    }
+
+    func testReplacesMultipletimesInLine() throws {
+        try fileAccessor.write(toPath: "/file", contents: "$(SRCROOT) and $(SRCROOT)")
+
+        try remapper.remap(fromGeneric: "/file")
+
+        try XCTAssertEqual(fileAccessor.contents(atPath: "/file"), "/example and /example")
+    }
+
+    func testReplacesInMultipleLine() throws {
+        try fileAccessor.write(toPath: "/file", contents: "$(SRCROOT)\n$(SRCROOT)")
+
+        try remapper.remap(fromGeneric: "/file")
+
+        try XCTAssertEqual(fileAccessor.contents(atPath: "/file"), "/example\n/example")
+    }
+}

Tests/XCRemoteCacheTests/Artifacts/UnzippedArtifactProcessorTests.swift

@@ -0,0 +1,71 @@
+// 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 UnzippedArtifactProcessorTests: FileXCTestCase {
+
+    private let fileAccessor = FileAccessorFake(mode: .strict)
+    private let remapper = StringDependenciesRemapper(mappings: [.init(generic: "$(SRCROOT)", local: "/local")])
+    private var fileRemapper: FileDependenciesRemapper!
+    private var processor: UnzippedArtifactProcessor!
+
+    override func setUp() {
+        super.setUp()
+        fileRemapper = TextFileDependenciesRemapper(remapper: remapper, fileAccessor: fileAccessor)
+        processor = UnzippedArtifactProcessor(
+            fileRemapper: fileRemapper,
+            dirScanner: fileAccessor
+        )
+    }
+
+    func testProcessingRawArtifactReplacesPlaceholders() throws {
+        try fileAccessor.write(toPath: "/artifact/include/file", contents: "Some $(SRCROOT)")
+
+        try processor.process(rawArtifact: "/artifact")
+
+        XCTAssertEqual(try fileAccessor.contents(atPath: "/artifact/include/file"), "Some /local")
+    }
+
+    func testProcessingRawArtifactReplacesInNestedInclude() throws {
+        try fileAccessor.write(toPath: "/artifact/include/nested/file", contents: "Some $(SRCROOT)")
+
+        try processor.process(rawArtifact: "/artifact")
+
+        XCTAssertEqual(try fileAccessor.contents(atPath: "/artifact/include/nested/file"), "Some /local")
+    }
+
+    func testProcessingRawArtifactDoesntReplacesInNonIncludeDir() throws {
+        try fileAccessor.write(toPath: "/artifact/some/file", contents: "Some $(SRCROOT)")
+
+        try processor.process(rawArtifact: "/artifact")
+
+        XCTAssertEqual(try fileAccessor.contents(atPath: "/artifact/some/file"), "Some $(SRCROOT)")
+    }
+
+    func testDoesntProcessEmptyFiles() throws {
+        try fileAccessor.write(toPath: "/artifact/include/.hidden", contents: "Some $(SRCROOT)")
+
+        try processor.process(rawArtifact: "/artifact")
+
+        XCTAssertEqual(try fileAccessor.contents(atPath: "/artifact/include/.hidden"), "Some $(SRCROOT)")
+    }
+}

Tests/XCRemoteCacheTests/Artifacts/ZipArtifactOrganizerTests.swift

@@ -54,7 +54,11 @@ class ZipArtifactOrganizerTests: XCTestCase {
 
     func testPreparePlacesArtifactInTheActiveLocation() throws {
         let zipURL = try prepareZipFile(content: "Magic", fileName: "content.txt")
-        let organizer = ZipArtifactOrganizer(targetTempDir: workingDirectory, fileManager: fileManager)
+        let organizer = ZipArtifactOrganizer(
+            targetTempDir: workingDirectory,
+            artifactProcessors: [],
+            fileManager: fileManager
+        )
 
         let preparedArtifact = try organizer.prepare(artifact: zipURL)
 
@@ -64,7 +68,11 @@ class ZipArtifactOrganizerTests: XCTestCase {
 
     func testPreparingExistingArtifact() throws {
         let zipURL = try prepareZipFile(content: "Magic", fileName: "content.txt")
-        let organizer = ZipArtifactOrganizer(targetTempDir: workingDirectory, fileManager: fileManager)
+        let organizer = ZipArtifactOrganizer(
+            targetTempDir: workingDirectory,
+            artifactProcessors: [],
+            fileManager: fileManager
+        )
 
         _ = try organizer.prepare(artifact: zipURL)
         let preparedArtifact = try organizer.prepare(artifact: zipURL)
@@ -75,7 +83,11 @@ class ZipArtifactOrganizerTests: XCTestCase {
 
     func testPreparePlacesArtifactInTheFileKeyRelatedLocation() throws {
         let zipURL = try prepareZipFile(content: "Magic", fileName: "content.txt", zipFileName: "abb32_fileKey")
-        let organizer = ZipArtifactOrganizer(targetTempDir: workingDirectory, fileManager: fileManager)
+        let organizer = ZipArtifactOrganizer(
+            targetTempDir: workingDirectory,
+            artifactProcessors: [],
+            fileManager: fileManager
+        )
         let expectedArtifactLocation = workingDirectory.appendingPathComponent("abb32_fileKey")
 
         let preparedArtifact = try organizer.prepare(artifact: zipURL)
@@ -89,7 +101,11 @@ class ZipArtifactOrganizerTests: XCTestCase {
         let artifactLocation = workingDirectory.appendingPathComponent("xccache")
             .appendingPathComponent(sampleFileKey, isDirectory: true)
         try fileManager.createDirectory(at: artifactLocation, withIntermediateDirectories: true, attributes: nil)
-        let organizer = ZipArtifactOrganizer(targetTempDir: workingDirectory, fileManager: fileManager)
+        let organizer = ZipArtifactOrganizer(
+            targetTempDir: workingDirectory,
+            artifactProcessors: [],
+            fileManager: fileManager
+        )
 
         let result = try organizer.prepareArtifactLocationFor(fileKey: sampleFileKey)
         if case .artifactExists(artifactDir: let u) = result {
@@ -105,7 +121,11 @@ class ZipArtifactOrganizerTests: XCTestCase {
             .appendingPathComponent("xccache")
             .appendingPathComponent(sampleFileKey)
             .appendingPathExtension("zip")
-        let organizer = ZipArtifactOrganizer(targetTempDir: workingDirectory, fileManager: fileManager)
+        let organizer = ZipArtifactOrganizer(
+            targetTempDir: workingDirectory,
+            artifactProcessors: [],
+            fileManager: fileManager
+        )
 
         let result = try organizer.prepareArtifactLocationFor(fileKey: sampleFileKey)
 
@@ -126,7 +146,11 @@ class ZipArtifactOrganizerTests: XCTestCase {
         try fileManager.createDirectory(at: activeArtifact, withIntermediateDirectories: true, attributes: nil)
         try fileManager.spt_forceSymbolicLink(at: activeLink, withDestinationURL: activeArtifact)
 
-        let organizer = ZipArtifactOrganizer(targetTempDir: workingDirectory, fileManager: fileManager)
+        let organizer = ZipArtifactOrganizer(
+            targetTempDir: workingDirectory,
+            artifactProcessors: [],
+            fileManager: fileManager
+        )
 
         let fileKey = try organizer.getActiveArtifactFilekey()
 

Tests/XCRemoteCacheTests/Commands/Plugins/Thinning/ThinningCreatorPluginTests.swift

@@ -131,7 +131,7 @@ class ThinningCreatorPluginTests: FileXCTestCase {
 
         XCTAssertEqual(extraKeys, [
             "thinning_Generated": "000",
-            "thinning_Reused": "999"
+            "thinning_Reused": "999",
         ])
     }
 }

Tests/XCRemoteCacheTests/Commands/Plugins/Thinning/ThinningDiskSwiftcProductsGeneratorTests.swift

@@ -67,7 +67,8 @@ class ThinningDiskSwiftcProductsGeneratorTests: FileXCTestCase {
             artifactSwiftModuleObjCFile: headerFile
         )
 
-        XCTAssertEqual(generatedModulePath, destinationSwiftModuleDir)
+        XCTAssertEqual(generatedModulePath.swiftmoduleDir, destinationSwiftModuleDir)
+        XCTAssertEqual(generatedModulePath.objcHeaderFile, objCHeader)
         XCTAssertEqual(fileManager.contents(atPath: expectedSwiftSourceInfoFile.path), "sourceInfo".data(using: .utf8))
         XCTAssertEqual(fileManager.contents(atPath: objCHeader.path), "header".data(using: .utf8))
     }

Tests/XCRemoteCacheTests/Commands/Plugins/Thinning/UnzippedArtifactSwiftProductsOrganizerTests.swift

@@ -30,6 +30,7 @@ class UnzippedArtifactSwiftProductsOrganizerTests: XCTestCase {
 
     override func setUpWithError() throws {
         try super.setUpWithError()
+        let destination = SwiftcProductsGeneratorOutput(swiftmoduleDir: destination, objcHeaderFile: "")
         generator = SwiftcProductsGeneratorSpy(generatedDestination: destination)
         dirAccessor = DirAccessorFake()
         syncer = FileFingerprintSyncer(

Tests/XCRemoteCacheTests/Commands/PostbuildContextTests.swift

@@ -26,6 +26,7 @@ class PostbuildContextTests: FileXCTestCase {
     private static let SampleEnvs = [
         "TARGET_NAME": "TARGET_NAME",
         "TARGET_TEMP_DIR": "TARGET_TEMP_DIR",
+        "DERIVED_FILE_DIR": "DERIVED_FILE_DIR",
         "ARCHS": "x86_64",
         "OBJECT_FILE_DIR_normal": "/OBJECT_FILE_DIR_normal" ,
         "CONFIGURATION": "CONFIGURATION",
@@ -42,7 +43,8 @@ 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"
+        "CURRENT_VARIANT": "normal",
+        "PUBLIC_HEADERS_FOLDER_PATH": "/usr/local/include",
     ]
 
     override func setUpWithError() throws {
@@ -129,4 +131,32 @@ class PostbuildContextTests: FileXCTestCase {
 
         XCTAssertEqual(context.compilationTempDir, "/OBJECT_FILE_DIR_custom/x86_64")
     }
+
+    func testGenericPublicHeaderDestinationIsSkipped() throws {
+        var envs = Self.SampleEnvs
+        envs["PUBLIC_HEADERS_FOLDER_PATH"] = "/usr/local/include"
+
+        let context = try PostbuildContext(config, env: envs)
+
+        XCTAssertNil(context.publicHeadersFolderPath)
+    }
+
+    func testPublicHeaderFolderIsRelativeToProductsDir() throws {
+        var envs = Self.SampleEnvs
+        envs["BUILT_PRODUCTS_DIR"] = "/MyBuiltProductsDir"
+        envs["PUBLIC_HEADERS_FOLDER_PATH"] = "MyModule.grameworks/Headers"
+
+        let context = try PostbuildContext(config, env: envs)
+
+        XCTAssertEqual(context.publicHeadersFolderPath, "/MyBuiltProductsDir/MyModule.grameworks/Headers")
+    }
+
+    func testPublicHeaderFolderPathEnvIsOptional() throws {
+        var envs = Self.SampleEnvs
+        envs.removeValue(forKey: "PUBLIC_HEADERS_FOLDER_PATH")
+
+        let context = try PostbuildContext(config, env: envs)
+
+        XCTAssertNil(context.publicHeadersFolderPath)
+    }
 }

Tests/XCRemoteCacheTests/Commands/PostbuildTests.swift

@@ -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: "",
@@ -52,7 +54,9 @@ class PostbuildTests: FileXCTestCase {
         thinnedTargets: [],
         action: .build,
         modeMarkerPath: "",
-        overlayHeadersPath: ""
+        overlayHeadersPath: "",
+        irrelevantDependenciesPaths: [],
+        publicHeadersFolderPath: nil
     )
     private var network = RemoteNetworkClientImpl(
         NetworkClientFake(fileManager: .default),
@@ -77,7 +81,9 @@ class PostbuildTests: FileXCTestCase {
         product: "/Product",
         source: "/Source",
         intermediate: "/Intermediate",
-        bundle: nil
+        derivedFiles: "/DerivedFiles",
+        bundle: nil,
+        skippedRegexes: []
     )
     private var overrideManager = FingerprintOverrideManagerImpl(
         overridingFileExtensions: ["swiftmodule"],
@@ -638,5 +644,79 @@ class PostbuildTests: FileXCTestCase {
 
         XCTAssertEqual(downloadedMeta, expectedMeta)
     }
+
+    func testDecoratesDerivedSwiftHeaderWithEmptyModulesFolderPath() throws {
+        let dir = try prepareTempDir()
+        let derivedSourcesDir = dir
+            .appendingPathComponent("DerivedSources")
+        let swiftSwiftHeader = derivedSourcesDir
+            .appendingPathComponent("MyModule-Swift.h")
+        let swiftSwiftHeaderOverride = swiftSwiftHeader
+            .appendingPathExtension("md5")
+
+        try fileManager.spt_createEmptyDir(derivedSourcesDir)
+        try fileManager.spt_createEmptyFile(swiftSwiftHeader)
+        postbuildContext.moduleName = "MyModule"
+        postbuildContext.derivedSourcesDir = derivedSourcesDir
+        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.performBuildCompletion()
+
+        XCTAssertTrue(fileManager.fileExists(atPath: swiftSwiftHeaderOverride.path))
+    }
+
+    func testDecoratesPublicSwiftHeaderWithEmptyModulesFolderPath() throws {
+        let dir = try prepareTempDir()
+        let productsDir = dir
+            .appendingPathComponent("MyModule.framework")
+            .appendingPathComponent("Headers")
+        let swiftSwiftHeader = productsDir
+            .appendingPathComponent("MyModule-Swift.h")
+        let swiftSwiftHeaderOverride = swiftSwiftHeader
+            .appendingPathExtension("md5")
+
+        try fileManager.spt_createEmptyDir(productsDir)
+        try fileManager.spt_createEmptyFile(swiftSwiftHeader)
+        postbuildContext.moduleName = "MyModule"
+        postbuildContext.publicHeadersFolderPath = productsDir
+        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.performBuildCompletion()
+
+        XCTAssertTrue(fileManager.fileExists(atPath: swiftSwiftHeaderOverride.path))
+    }
 }
-// swiftlint:disable:next file_length

Tests/XCRemoteCacheTests/Commands/Prepare/Integrate/XcodeProjBuildSettingsIntegrateAppenderTests.swift

@@ -0,0 +1,73 @@
+// 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)
+    }
+
+    func testConsumerSettingLdPlusPlus() 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 ldPlusPlus: String = try XCTUnwrap(result["LDPLUSPLUS"] as? String)
+
+        XCTAssertEqual(ldPlusPlus, binaries.ldplusplus.path)
+    }
+}

Tests/XCRemoteCacheTests/Commands/SwiftcTests.swift

@@ -70,7 +70,9 @@ class SwiftcTests: FileXCTestCase {
         )
         context = try SwiftcContext(config: config, input: input)
         markerWriter = MarkerWriterSpy()
-        productsGenerator = SwiftcProductsGeneratorSpy()
+        productsGenerator = SwiftcProductsGeneratorSpy(
+            generatedDestination: SwiftcProductsGeneratorOutput(swiftmoduleDir: "", objcHeaderFile: "")
+        )
         let dependenciesWriterSpy = DependenciesWriterSpy()
         self.dependenciesWriterSpy = dependenciesWriterSpy
         dependenciesWriterFactory = { [dependenciesWriterSpy] _, _ in dependenciesWriterSpy }
@@ -283,6 +285,12 @@ class SwiftcTests: FileXCTestCase {
         let artifactSwiftInterfaceInfo = URL(
             fileURLWithPath: "/cachedArtifact/swiftmodule/archTest/Target.swiftinterface"
         )
+        let artifactPrivateSwiftInterfaceInfo = URL(
+            fileURLWithPath: "/cachedArtifact/swiftmodule/archTest/Target.private.swiftinterface"
+        )
+        let artifactAbiJsonInfo = URL(
+            fileURLWithPath: "/cachedArtifact/swiftmodule/archTest/Target.abi.json"
+        )
 
         artifactOrganizer = ArtifactOrganizerFake(artifactRoot: artifactRoot)
         let swiftc = Swiftc(
@@ -303,17 +311,14 @@ class SwiftcTests: FileXCTestCase {
         _ = try swiftc.mockCompilation()
 
         let swiftModuleFiles = try productsGenerator.generated.first.unwrap()
-        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)
+        XCTAssertEqual(swiftModuleFiles.0[.swiftmodule], artifactSwiftmodule)
+        XCTAssertEqual(swiftModuleFiles.0[.swiftdoc], artifactSwiftdoc)
+        XCTAssertEqual(swiftModuleFiles.0[.swiftsourceinfo], artifactSwiftSourceInfo)
+        XCTAssertEqual(swiftModuleFiles.0[.swiftinterface], artifactSwiftInterfaceInfo)
+        XCTAssertEqual(swiftModuleFiles.0[.privateSwiftinterface], artifactPrivateSwiftInterfaceInfo)
+        XCTAssertEqual(swiftModuleFiles.0[.abiJson], artifactAbiJsonInfo)
+        XCTAssertEqual(swiftModuleFiles.1, artifactObjCHeader)
     }
 
 

Tests/XCRemoteCacheTests/Commands/XCCCTests.swift

@@ -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 +333,42 @@ class TemplateBasedCCWrapperBuilderTests: FileXCTestCase {
         XCTAssertNotEqual(newFileOutputData, Data())
     }
 
+    func testPCHObjCCompilationFallbacks() 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))
+    }
+
+    func testPCHCCompilationFallbacks() throws {
+        // Marker is empty to mimic the new file scenario
+        let pchFile = directory.appendingPathComponent("input.pch")
+        createValidPCHFile(pchFile)
+        arguments = ["-x", "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(

Tests/XCRemoteCacheTests/Config/XCRemoteCacheConfigReaderTests.swift

@@ -0,0 +1,95 @@
+// 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 {
+        let contents = [
+            "cache_addresses: [test]",
+            "retry_delay: 30",
+            "upload_batch_size: 5",
+        ].joined(separator: "\n").data(using: .utf8)
+        try fileReader.write(toPath: "/.rcinfo", contents: contents)
+
+        let config = try reader.readConfiguration()
+
+        XCTAssertEqual(config.cacheAddresses, ["test"])
+        XCTAssertEqual(config.retryDelay, 30)
+        XCTAssertEqual(config.uploadBatchSize, 5)
+    }
+
+    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")
+    }
+}

Tests/XCRemoteCacheTests/Dependencies/DependenciesReaderPerformanceTest.swift

@@ -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)
+        }
+    }
+}

Tests/XCRemoteCacheTests/Dependencies/DependenciesRemapperCompositeTests.swift

@@ -81,8 +81,18 @@ class DependenciesRemapperCompositeTests: XCTestCase {
 
     func testRemapsMultipleMatchingMappers() throws {
         let remapper = DependenciesRemapperComposite([
-            StringDependenciesRemapper(mappings: [StringDependenciesRemapper.Mapping(generic: "$(ROOT)", local: "/root")]),
-            StringDependenciesRemapper(mappings: [StringDependenciesRemapper.Mapping(generic: "$(SPECIFIC)", local: "$(ROOT)/specific")])
+            StringDependenciesRemapper(mappings: [
+                StringDependenciesRemapper.Mapping(
+                    generic: "$(ROOT)",
+                    local: "/root"
+                ),
+            ]),
+            StringDependenciesRemapper(mappings: [
+                StringDependenciesRemapper.Mapping(
+                    generic: "$(SPECIFIC)",
+                    local: "$(ROOT)/specific"
+                ),
+            ]),
         ])
         let localPaths = ["/root/specific/file"]
 
@@ -93,8 +103,18 @@ class DependenciesRemapperCompositeTests: XCTestCase {
 
     func testRemapsBackToLocalWithRevertedRemappersOrder() throws {
         let remapper = DependenciesRemapperComposite([
-            StringDependenciesRemapper(mappings: [StringDependenciesRemapper.Mapping(generic: "$(ROOT)", local: "/root")]),
-            StringDependenciesRemapper(mappings: [StringDependenciesRemapper.Mapping(generic: "$(SPECIFIC)", local: "$(ROOT)/specific")])
+            StringDependenciesRemapper(mappings: [
+                StringDependenciesRemapper.Mapping(
+                    generic: "$(ROOT)",
+                    local: "/root"
+                ),
+            ]),
+            StringDependenciesRemapper(mappings: [
+                StringDependenciesRemapper.Mapping(
+                    generic: "$(SPECIFIC)",
+                    local: "$(ROOT)/specific"
+                ),
+            ]),
         ])
         let genericPaths = ["$(SPECIFIC)/file"]
 
@@ -105,8 +125,18 @@ class DependenciesRemapperCompositeTests: XCTestCase {
 
     func testRemappingTwoMappingsBackAndForthIsIdentical() throws {
         let remapper = DependenciesRemapperComposite([
-            StringDependenciesRemapper(mappings: [StringDependenciesRemapper.Mapping(generic: "$(ROOT)", local: "/root")]),
-            StringDependenciesRemapper(mappings: [StringDependenciesRemapper.Mapping(generic: "$(SPECIFIC)", local: "$(ROOT)/specific")])
+            StringDependenciesRemapper(mappings: [
+                StringDependenciesRemapper.Mapping(
+                    generic: "$(ROOT)",
+                    local: "/root"
+                ),
+            ]),
+            StringDependenciesRemapper(mappings: [
+                StringDependenciesRemapper.Mapping(
+                    generic: "$(SPECIFIC)",
+                    local: "$(ROOT)/specific"
+                ),
+            ]),
         ])
         let localPaths = ["/root/specific/file"]
 

Tests/XCRemoteCacheTests/Dependencies/DependenciesWriterTests.swift

@@ -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)
+    }
+}

Tests/XCRemoteCacheTests/Dependencies/DependencyProcessorImplTests.swift

@@ -27,17 +27,21 @@ class DependencyProcessorImplTests: FileXCTestCase {
         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: FileXCTestCase {
         )
     }
 
-    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: FileXCTestCase {
         )
     }
 
+    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",
@@ -130,13 +152,19 @@ class DependencyProcessorImplTests: FileXCTestCase {
             product: "/Product",
             source: "/Source",
             intermediate: intermediateDirReal,
-            bundle: "/Bundle"
+            derivedFiles: "/DerivedFiles",
+            bundle: "/Bundle",
+            skippedRegexes: []
         )
 
-        let intermediateFileSymlink = createSymlink(filename: someFilename, sourceDir: symlink, destinationDir: intermediateDirReal)
+        let intermediateFileSymlink = createSymlink(
+            filename: someFilename,
+            sourceDir: symlink,
+            destinationDir: intermediateDirReal
+        )
 
         let dependencies = processor.process([
-            intermediateFileSymlink
+            intermediateFileSymlink,
         ])
 
         XCTAssertEqual(dependencies, [])
@@ -154,13 +182,19 @@ class DependencyProcessorImplTests: FileXCTestCase {
             product: "/Product",
             source: sourceDirReal,
             intermediate: "/Intermediate",
-            bundle: "/Bundle"
+            derivedFiles: "/DerivedFiles",
+            bundle: "/Bundle",
+            skippedRegexes: []
         )
 
-        let sourceFileSymlink = createSymlink(filename: someFilename, sourceDir: symlink, destinationDir: sourceDirReal)
+        let sourceFileSymlink = createSymlink(
+            filename: someFilename,
+            sourceDir: symlink,
+            destinationDir: sourceDirReal
+        )
 
         let dependencies = processor.process([
-            sourceFileSymlink
+            sourceFileSymlink,
         ])
 
         XCTAssertEqual(dependencies, [.init(url: sourceFileSymlink, type: .source)])
@@ -173,10 +207,84 @@ class DependencyProcessorImplTests: FileXCTestCase {
     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_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)]
+        )
+    }
 }

Tests/XCRemoteCacheTests/Dependencies/FileFingerprintSyncerTests.swift

@@ -74,4 +74,51 @@ class FileFingerprintSyncerTests: FileXCTestCase {
 
         XCTAssertTrue(fileManager.fileExists(atPath: nonOverrideFile.path))
     }
+
+    func testDecoratesFile() throws {
+        let header = swiftmoduleDir.appendingPathComponent("Module-Swift.h")
+        let headerOverride = swiftmoduleDir.appendingPathComponent("Module-Swift.h.md5")
+        try fileManager.spt_createEmptyFile(header)
+
+
+        try syncer.decorate(file: header, fingerprint: "1")
+
+        XCTAssertEqual(try String(contentsOf: headerOverride), "1")
+    }
+
+    func testFileDecorateOverridesPreviousOverlay() throws {
+        let header = swiftmoduleDir.appendingPathComponent("Module-Swift.h")
+        let headerOverride = swiftmoduleDir.appendingPathComponent("Module-Swift.h.md5")
+        try fileManager.spt_createEmptyFile(header)
+        try "1".write(to: headerOverride, atomically: true, encoding: .utf8)
+
+        try syncer.decorate(file: header, fingerprint: "2")
+
+        XCTAssertEqual(try String(contentsOf: headerOverride), "2")
+    }
+
+    func testDeletesFileOverride() throws {
+        let header = swiftmoduleDir.appendingPathComponent("Module-Swift.h")
+        let headerOverride = swiftmoduleDir.appendingPathComponent("Module-Swift.h.md5")
+        try fileManager.spt_createEmptyFile(header)
+        try fileManager.spt_createEmptyFile(headerOverride)
+
+
+        try syncer.delete(file: header)
+
+        XCTAssertFalse(fileManager.fileExists(atPath: headerOverride.path))
+    }
+
+    func testDeletesDoesntDeleteWhenFileIsMissing() throws {
+        let nonExistingFile = swiftmoduleDir.appendingPathComponent("Module-Swift.h")
+
+        XCTAssertNoThrow(try syncer.delete(file: nonExistingFile))
+    }
+
+    func testDeletesDoesntDeleteWhenOverrideIsMissing() throws {
+        let header = swiftmoduleDir.appendingPathComponent("Module-Swift.h")
+        try fileManager.spt_createEmptyFile(header)
+
+        XCTAssertNoThrow(try syncer.delete(file: header))
+    }
 }

Tests/XCRemoteCacheTests/Dependencies/OverlayDependenciesRemapperTests.swift

@@ -68,4 +68,3 @@ class OverlayDependenciesRemapperTests: XCTestCase {
         XCTAssertEqual(secondDependencies, ["/file.h"])
     }
 }
-

Tests/XCRemoteCacheTests/Dependencies/OverlayReaderTests.swift

@@ -29,8 +29,14 @@ class JsonOverlayReaderTests: FileXCTestCase {
         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")
+            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))
     }
@@ -79,6 +85,10 @@ class JsonOverlayReaderTests: FileXCTestCase {
     }
 
     private func pathForTestData(name: String) throws -> URL {
-        return try XCTUnwrap(Bundle.module.url(forResource: name, withExtension: "json", subdirectory: JsonOverlayReaderTests.resourcesSubdirectory))
+        return try XCTUnwrap(Bundle.module.url(
+            forResource: name,
+            withExtension: "json",
+            subdirectory: JsonOverlayReaderTests.resourcesSubdirectory
+        ))
     }
 }

Tests/XCRemoteCacheTests/Dependencies/PathDependenciesRemapperFactoryTests.swift

@@ -20,11 +20,12 @@
 @testable import XCRemoteCache
 import XCTest
 
-class StringDependenciesRemapperFactoryTests: XCTestCase {
-    private var factory: StringDependenciesRemapperFactory!
+class PathDependenciesRemapperFactoryTests: XCTestCase {
+    private var factory: PathDependenciesRemapperFactory!
 
     override func setUp() {
-        factory = StringDependenciesRemapperFactory()
+        super.setUp()
+        factory = PathDependenciesRemapperFactory()
     }
 
     func testMappingsFromEnvMaps() throws {
@@ -38,8 +39,30 @@ class StringDependenciesRemapperFactoryTests: XCTestCase {
         XCTAssertEqual(localPaths, ["/tmp/root/some.swift"])
     }
 
-    func testInvalidMappingsFromEnvFails() throws {
-        XCTAssertThrowsError(
+    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": ""],

Tests/XCRemoteCacheTests/FileAccess/DirScannerTests.swift

@@ -71,4 +71,17 @@ class FileManagerDirScannerTests: FileXCTestCase {
 
         try XCTAssertThrowsError(dirScanner.items(at: dir))
     }
+
+    func testFindsAllFilesRecursively() throws {
+        let dir = workingDirectory!.appendingPathComponent("dir")
+        let nestedDir = dir.appendingPathComponent("nested")
+        let nestedFile = nestedDir.appendingPathComponent("file")
+        try fileManager.spt_createEmptyFile(nestedFile)
+
+        let allFiles = try dirScanner.recursiveItems(at: dir)
+
+        // returned items may contain symbolic links in a path
+        let allFilesResolve = allFiles.map { $0.resolvingSymlinksInPath() }
+        XCTAssertEqual(allFilesResolve, [nestedFile])
+    }
 }

Tests/XCRemoteCacheTests/Fingerprint/EnvironmentFingerprintGeneratorTests.swift

@@ -33,19 +33,23 @@ class EnvironmentFingerprintGeneratorTests: XCTestCase {
         "DYLIB_COMPATIBILITY_VERSION": "2",
         "DYLIB_CURRENT_VERSION": "3",
         "PRODUCT_MODULE_NAME": "4",
-        "ARCHS": "AR"
+        "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,
@@ -92,4 +96,11 @@ class EnvironmentFingerprintGeneratorTests: XCTestCase {
 
         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)
+    }
 }

Tests/XCRemoteCacheTests/Network/Authentication/AWSV4SignatureTest.swift

@@ -35,10 +35,12 @@ class AWSV4SignatureTest: XCTestCase {
 
         let key = "wJalrXUtnFEMI/K7MDENG+bPxRfiCYEXAMPLEKEY"
         let accessKey = "AKIDEXAMPLE"
+        let securityToken = "IQoJb3JpZ2luX2VjENv//////////wEaCXVzLWVhc3Q+bsHwqnovXtl/1JVe61XHMnAw3AIXwOAOxqMvhw=="
 
         AWSV4Signature(
             secretKey: key,
             accessKey: accessKey,
+            securityToken: securityToken,
             region: "us-east-1",
             service: "iam",
             date: Date(timeIntervalSince1970: 1_440_938_160)
@@ -49,8 +51,8 @@ class AWSV4SignatureTest: XCTestCase {
     func testAuthHeaderContainsCorrectSignature() throws {
         XCTAssertEqual(
             "AWS4-HMAC-SHA256 Credential=AKIDEXAMPLE/20150830/us-east-1/iam/aws4_request, " +
-                "SignedHeaders=content-type;host;x-amz-content-sha256;x-amz-date, " +
-                "Signature=dd479fa8a80364edf2119ec24bebde66712ee9c9cb2b0d92eb3ab9ccdc0c3947",
+                "SignedHeaders=content-type;host;x-amz-content-sha256;x-amz-date;x-amz-security-token, " +
+                "Signature=d26ab974bba1b248f041ea1120064e1fa672d6f06cac2cff42b38acea87b76e5",
             request.allHTTPHeaderFields?["Authorization"]
         )
     }

Tests/XCRemoteCacheTests/Network/NetworkClientImplTests.swift

@@ -72,7 +72,13 @@ class NetworkClientImplTests: XCTestCase {
         configuration.protocolClasses = [URLProtocolStub.self]
         session = URLSession(configuration: configuration)
         fileManager = FileManager.default
-        client = NetworkClientImpl(session: session, retries: 0, fileManager: fileManager, awsV4Signature: nil)
+        client = NetworkClientImpl(
+            session: session,
+            retries: 0,
+            retryDelay: 0,
+            fileManager: fileManager,
+            awsV4Signature: nil
+        )
     }
 
     override func tearDown() {
@@ -87,7 +93,7 @@ class NetworkClientImplTests: XCTestCase {
         super.tearDown()
     }
 
-    func waitForResponse<R>(_ action: (@escaping Completion<R>) -> Void) throws -> Result<R, NetworkClientError> {
+    func waitForResponse<R>(_ action: (@escaping Completion<R>) -> Void, timeout: TimeInterval = 0.1) throws -> Result<R, NetworkClientError> {
         let responseExpectation = expectation(description: "RequestResponse")
         var receivedResponse: Result<R, NetworkClientError>?
 
@@ -95,7 +101,7 @@ class NetworkClientImplTests: XCTestCase {
             receivedResponse = response
             responseExpectation.fulfill()
         }
-        waitForExpectations(timeout: 0.1)
+        waitForExpectations(timeout: timeout)
         return try receivedResponse.unwrap()
     }
 
@@ -141,9 +147,15 @@ class NetworkClientImplTests: XCTestCase {
     }
 
     func testUploadFilureWith400Retries() throws {
-        client = NetworkClientImpl(session: session, retries: 2, fileManager: fileManager, awsV4Signature: nil)
+        client = NetworkClientImpl(
+            session: session,
+            retries: 2,
+            retryDelay: 0,
+            fileManager: fileManager,
+            awsV4Signature: nil
+        )
         responses[url] = .success(failureResponse, Data())
-        _ = try waitForResponse { client.upload(fileURL, as: url, completion: $0) }
+        _ = try waitForResponse({ client.upload(fileURL, as: url, completion: $0) }, timeout: 0.5)
 
         XCTAssertEqual(
             requests.map(\.url),
@@ -153,13 +165,51 @@ class NetworkClientImplTests: XCTestCase {
     }
 
     func testUploadSuccessDoesntRetry() throws {
-        client = NetworkClientImpl(session: session, retries: 0, fileManager: fileManager, awsV4Signature: nil)
+        client = NetworkClientImpl(
+            session: session,
+            retries: 2,
+            retryDelay: 0,
+            fileManager: fileManager,
+            awsV4Signature: nil
+        )
         responses[url] = .success(successResponse, Data())
         _ = try waitForResponse { client.upload(fileURL, as: url, completion: $0) }
 
         XCTAssertEqual(requests.map(\.url), [url], "Expected 1 request - original only")
     }
 
+    func testDownloadFilureWith400Retries() throws {
+        client = NetworkClientImpl(
+            session: session,
+            retries: 2,
+            retryDelay: 0,
+            fileManager: fileManager,
+            awsV4Signature: nil
+        )
+        responses[url] = nil
+        _ = try waitForResponse({ client.download(url, to: fileURL, completion: $0) }, timeout: 0.5)
+
+        XCTAssertEqual(
+            requests.map(\.url),
+            Array(repeating: url, count: 3),
+            "Expected 3 requests (original + 2 retries)"
+        )
+    }
+
+    func testDownloadSuccessDoesntRetry() throws {
+        client = NetworkClientImpl(
+            session: session,
+            retries: 2,
+            retryDelay: 0,
+            fileManager: fileManager,
+            awsV4Signature: nil
+        )
+        responses[url] = .success(successResponse, Data())
+        _ = try waitForResponse { client.download(url, to: fileURL, completion: $0) }
+
+        XCTAssertEqual(requests.map(\.url), [url], "Expected 1 request - original only")
+    }
+
     func testFileExits400CompletesWithFalse() throws {
         responses[url] = .success(failureResponse, Data())
         let response = try waitForResponse { client.fileExists(url, completion: $0) }
@@ -203,18 +253,25 @@ class NetworkClientImplTests: XCTestCase {
         let signature = AWSV4Signature(
             secretKey: "wJalrXUtnFEMI/K7MDENG+bPxRfiCYEXAMPLEKEY",
             accessKey: "AKIDEXAMPLE",
+            securityToken: "IQoJb3JpZ2luX2VjENv//////////wEaCXVzLWVhc3Q+bsHwqnovXtl/1JVe61XHMnAw3AIXwOAOxqMvhw==",
             region: "us-east-1",
             service: "iam",
             date: Date(timeIntervalSince1970: 1_440_938_160)
         )
-        client = NetworkClientImpl(session: session, retries: 0, fileManager: fileManager, awsV4Signature: signature)
+        client = NetworkClientImpl(
+            session: session,
+            retries: 0,
+            retryDelay: 0,
+            fileManager: fileManager,
+            awsV4Signature: signature
+        )
         responses[url] = .success(successResponse, Data())
         _ = try waitForResponse { client.fetch(url, completion: $0) }
 
         XCTAssertEqual(
             "AWS4-HMAC-SHA256 Credential=AKIDEXAMPLE/20150830/us-east-1/iam/aws4_request, " +
-                "SignedHeaders=host;x-amz-content-sha256;x-amz-date, " +
-                "Signature=acdb223475463b6ce711b063f199387a7a12bd638e4dccaaeb5efcbf159b6454",
+                "SignedHeaders=host;x-amz-content-sha256;x-amz-date;x-amz-security-token, " +
+                "Signature=e5578464567fb97fd26e871702e4ec4ff7d61cb87eb72a40d22b80e12da30c34",
             try requests[0].allHTTPHeaderFields?["Authorization"].unwrap()
         )
     }

Tests/XCRemoteCacheTests/Network/ReplicatedRemotesNetworkClientTests.swift

@@ -39,7 +39,12 @@ class ReplicatedRemotesNetworkClientTests: XCTestCase {
         uploadURLs = try [URL(string: "http://upload1.com").unwrap(), URL(string: "http://upload2.com").unwrap()]
         download = URLBuilderFake(downloadURL)
         uploads = uploadURLs.map(URLBuilderFake.init)
-        client = ReplicatedRemotesNetworkClient(networkClient, download: download, uploads: uploads)
+        client = ReplicatedRemotesNetworkClient(
+            networkClient,
+            download: download,
+            uploads: uploads,
+            uploadBatchSize: 1
+        )
     }
 
     private func prepareLocalEmptyFile() throws -> URL {
@@ -62,6 +67,30 @@ class ReplicatedRemotesNetworkClientTests: XCTestCase {
         XCTAssertTrue(try networkClient.fileExistsSynchronously(expectedArtifact2))
     }
 
+    func testUploadsWithLimit() throws {
+        var expectedArtifacts = [URL]()
+        var uploadURLs = [URL]()
+        for index in 0...99 {
+            let expectedArtifact = try URL(string: "http://upload\(index).com/file/id1").unwrap()
+            expectedArtifacts.append(expectedArtifact)
+            let uploadURL = try URL(string: "http://upload\(index).com").unwrap()
+            uploadURLs.append(uploadURL)
+        }
+        uploads = uploadURLs.map(URLBuilderFake.init)
+        client = ReplicatedRemotesNetworkClient(
+            networkClient,
+            download: download,
+            uploads: uploads,
+            uploadBatchSize: 10
+        )
+
+        try client.uploadSynchronously(localSampleFile, as: .artifact(id: "id1"))
+
+        for expectedArtifact in expectedArtifacts {
+            XCTAssertTrue(try networkClient.fileExistsSynchronously(expectedArtifact))
+        }
+    }
+
     func testCreatesInAllStreams() throws {
         let expectedMeta1 = try URL(string: "http://upload1.com/meta/commit_id").unwrap()
         let expectedMeta2 = try URL(string: "http://upload2.com/meta/commit_id").unwrap()
@@ -71,4 +100,5 @@ class ReplicatedRemotesNetworkClientTests: XCTestCase {
         XCTAssertTrue(try networkClient.fileExistsSynchronously(expectedMeta1))
         XCTAssertTrue(try networkClient.fileExistsSynchronously(expectedMeta2))
     }
+
 }

Tests/XCRemoteCacheTests/TestDoubles/DirAccessorFake.swift

@@ -47,6 +47,16 @@ class DirAccessorFake: DirAccessor {
         }
     }
 
+    func recursiveItems(at dir: URL) throws -> [URL] {
+        memory.compactMap { url, _ in
+            // comparing paths to ignore dir or url's "isDir" property
+            if url.deletingLastPathComponent().path.starts(with: dir.path) {
+                return url
+            }
+            return nil
+        }
+    }
+
     func contents(atPath path: String) throws -> Data? {
         memory[URL(fileURLWithPath: path)]
     }