Introduce mimalloc to static Linux binaries (#6321)

mimalloc is performant memory allocator written in C that works as drop-in replacement for malloc and supports builds for musl. Compared with other popular allocators like jemalloc or tcmalloc, it's a fair option. 

https://github.com/microsoft/mimalloc

Also, in the Swift compiler project (swiftlang/swift), mimaloc has been adopted as the allocator in Windows's toolchain (not runtime!):

https://forums.swift.org/t/se-454-adopt-mimalloc-for-windows-toolchain/

Co-authored-by: Danny Mösch <danny.moesch@icloud.com>

.github/workflows/release.yml

@@ -15,6 +15,7 @@ on:
 env:
   DEVELOPER_DIR: /Applications/Xcode_26.0.1.app
   RELEASE_BRANCH: release/${{ inputs.version }}
+  MIMALLOC_VERSION: 3.0.10
 
 jobs:
   setup-credentials:
@@ -144,21 +145,39 @@ jobs:
           persist-credentials: false
       - name: Install SDK
         run: swift sdk install https://download.swift.org/swift-6.2-release/static-sdk/swift-6.2-RELEASE/swift-6.2-RELEASE_static-linux-0.0.1.artifactbundle.tar.gz --checksum d2225840e592389ca517bbf71652f7003dbf45ac35d1e57d98b9250368769378
+      - name: Build mimalloc object
+        run: |
+          set -euxo pipefail
+          curl -sSfL "https://github.com/microsoft/mimalloc/archive/refs/tags/v${MIMALLOC_VERSION}.tar.gz" | tar xz
+          export CC=clang
+          cmake -S "mimalloc-${MIMALLOC_VERSION}" -B mimalloc-build \
+            -DMI_BUILD_SHARED=OFF \
+            -DMI_BUILD_STATIC=ON \
+            -DMI_BUILD_OBJECT=OFF \
+            -DCMAKE_BUILD_TYPE=Release
+          cmake --build mimalloc-build --target mimalloc-static
       - name: Build static binary
         run: |
+          # To improve performance with musl, increase the stack size to 512KiB and
+          # replace musl's default allocator with mimalloc.
           swift build \
             -c release \
             --product swiftlint \
             --swift-sdk ${{ matrix.swift_sdk }} \
             -Xswiftc -DSWIFTLINT_DISABLE_SOURCEKIT \
-            -Xlinker -z -Xlinker stack-size=0x80000 # 512KiB
+            -Xlinker -z -Xlinker stack-size=0x80000 \
+            -Xlinker --whole-archive \
+            -Xlinker ./mimalloc-build/libmimalloc.a \
+            -Xlinker --no-whole-archive
       - name: Strip binary
         run: strip -s "$BINARY_PATH"
       - name: Upload artifact
         uses: actions/upload-artifact@330a01c490aca151604b8cf639adc76d48f6c5d4 # v5.0.0
         with:
           name: ${{ matrix.artifact_name }}
-          path: ${{ env.BINARY_PATH }}
+          path: |
+            ${{ env.BINARY_PATH }}
+            mimalloc-build/LICENSE
 
   build-macos:
     name: Build macOS Binaries
@@ -214,6 +233,9 @@ jobs:
           mv -f swiftlint-linux-arm64/swiftlint swiftlint_linux_arm64
           mv -f swiftlint-static-amd64/swiftlint swiftlint_static_amd64
           mv -f swiftlint-static-arm64/swiftlint swiftlint_static_arm64
+
+          # Just pick one of the licenses.
+          mv -f swiftlint-static-amd64/LICENSE LICENSE.mimalloc
       - name: Make binaries executable
         run: chmod +x swiftlint*
       - name: Create artifacts

CHANGELOG.md

@@ -29,6 +29,11 @@
   [nandhinisubbu](https://github.com/nandhinisubbu)
   [#6161](https://github.com/realm/SwiftLint/issues/6161)
 
+* Adopt [mimalloc](https://github.com/microsoft/mimalloc) for static Linux binary
+  to improve performance.  
+  [ainame](https://github.com/ainame)
+  [#6298](https://github.com/realm/SwiftLint/issues/6298)
+
 ### Bug Fixes
 
 * Fix false positive with `#Preview` macro in `closure_end_indentation` rule.  

Makefile

@@ -119,11 +119,11 @@ zip_linux_release: swiftlint_linux_amd64 swiftlint_linux_arm64 swiftlint_static_
 	$(eval TMP_FOLDER := $(shell mktemp -d))
 	cp -f swiftlint_linux_amd64 "$(TMP_FOLDER)/swiftlint"
 	cp -f swiftlint_static_amd64 "$(TMP_FOLDER)/swiftlint-static"
-	cp -f LICENSE "$(TMP_FOLDER)"
-	(cd "$(TMP_FOLDER)"; zip -yr - "swiftlint" "swiftlint-static" "LICENSE") > "./swiftlint_linux_amd64.zip"
+	cp -f LICENSE LICENSE.mimalloc "$(TMP_FOLDER)"
+	(cd "$(TMP_FOLDER)"; zip -yr - "swiftlint" "swiftlint-static" "LICENSE" "LICENSE.mimalloc") > "./swiftlint_linux_amd64.zip"
 	cp -f swiftlint_linux_arm64 "$(TMP_FOLDER)/swiftlint"
 	cp -f swiftlint_static_arm64 "$(TMP_FOLDER)/swiftlint-static"
-	(cd "$(TMP_FOLDER)"; zip -yr - "swiftlint" "swiftlint-static" "LICENSE") > "./swiftlint_linux_arm64.zip"
+	(cd "$(TMP_FOLDER)"; zip -yr - "swiftlint" "swiftlint-static" "LICENSE" "LICENSE.mimalloc") > "./swiftlint_linux_arm64.zip"
 
 package: swiftlint
 	$(eval PACKAGE_ROOT := $(shell mktemp -d))