Enable building only compiler-rt

Author: TartanLlama

.github/workflows/main.yml

@@ -25,12 +25,12 @@ jobs:
           - artifact: x86_64-linux
             os: ubuntu-24.04
             env:
-              WASI_SDK_CI_SKIP_SYSROOT: 1
+              WASI_SDK_CI_COMPILER_RT_ONLY: 1
 
           - artifact: arm64-linux
             os: ubuntu-22.04-arm
             env:
-              WASI_SDK_CI_SKIP_SYSROOT: 1
+              WASI_SDK_CI_COMPILER_RT_ONLY: 1
 
           - artifact: riscv64-linux
             os: ubuntu-24.04
@@ -51,7 +51,7 @@ jobs:
             os: macos-14
             rust_target: aarch64-apple-darwin
             env:
-              WASI_SDK_CI_SKIP_SYSROOT: 1
+              WASI_SDK_CI_COMPILER_RT_ONLY: 1
               WASI_SDK_CI_TOOLCHAIN_LLVM_CMAKE_ARGS: >-
                 -DCMAKE_OSX_DEPLOYMENT_TARGET=10.12
                 -DCMAKE_OSX_ARCHITECTURES=arm64
@@ -60,20 +60,20 @@ jobs:
             os: macos-14
             rust_target: x86_64-apple-darwin
             env:
-              WASI_SDK_CI_SKIP_SYSROOT: 1
+              WASI_SDK_CI_COMPILER_RT_ONLY: 1
               WASI_SDK_CI_TOOLCHAIN_LLVM_CMAKE_ARGS: >-
                 -DCMAKE_OSX_DEPLOYMENT_TARGET=10.12
                 -DCMAKE_OSX_ARCHITECTURES=x86_64
 
           - artifact: x86_64-windows
             os: windows-2022
             env:
-              WASI_SDK_CI_SKIP_SYSROOT: 1
+              WASI_SDK_CI_COMPILER_RT_ONLY: 1
 
           - artifact: arm64-windows
             os: windows-11-arm
             env:
-              WASI_SDK_CI_SKIP_SYSROOT: 1
+              WASI_SDK_CI_COMPILER_RT_ONLY: 1
 
     env: ${{ matrix.env || fromJSON('{}') }}
     steps:
@@ -181,6 +181,44 @@ jobs:
           path: ${{ runner.tool_cache }}/ccache
           key: 0-cache-${{ matrix.artifact }}-${{ github.run_id }}
 
+  build-only-sysroot:
+    name: Build only sysroot - ${{ matrix.name }}
+    runs-on: ubuntu-24.04
+    strategy:
+      matrix:
+        include:
+          - name: default
+          - name: exceptions
+            defines: -DWASI_SDK_EXCEPTIONS=ON
+          - name: static
+            defines: -DWASI_SDK_BUILD_SHARED=OFF
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          fetch-depth: 0
+      - uses: ./.github/actions/checkout
+      - uses: ./.github/actions/install-deps
+      - run: cargo install wasm-component-ld@0.5.21
+      - name: Install LLVM 22
+        run: |
+          v=22
+          rel=$(lsb_release -cs)
+          wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo tee /etc/apt/keyrings/llvm.asc
+          echo "deb [signed-by=/etc/apt/keyrings/llvm.asc] http://apt.llvm.org/$rel/ llvm-toolchain-$rel-$v main" | sudo tee /etc/apt/sources.list.d/llvm-$v.list
+          sudo apt-get update -y && sudo apt-get install -y clang-$v lld-$v
+      - run: |
+          cmake -G Ninja -B build -S . \
+            -DCMAKE_C_COMPILER=/usr/lib/llvm-22/bin/clang \
+            -DCMAKE_SYSTEM_NAME=WASI \
+            -DWASI_SDK_INCLUDE_TESTS=ON \
+            -DWASI_SDK_CPU_CFLAGS="" \
+            -DCMAKE_C_LINKER_DEPFILE_SUPPORTED=OFF \
+            -DCMAKE_CXX_LINKER_DEPFILE_SUPPORTED=OFF \
+            ${{ matrix.defines }}
+      - run: ninja -C build
+      - run: ctest --output-on-failure --parallel 10 --test-dir build/tests
+
+
   # Once all of the above matrix entries have completed this job will run and
   # assemble the final `wasi-sdk-*` artifacts by fusing the toolchain/sysroot
   # artifacts.

ci/build.sh

@@ -38,6 +38,7 @@ cmake -G Ninja -B $build_dir/sysroot -S . \
   -DCMAKE_CXX_COMPILER_WORKS=ON \
   -DWASI_SDK_INCLUDE_TESTS=ON \
   -DWASI_SDK_EXCEPTIONS=DUAL \
+  -DWASI_SDK_COMPILER_RT_ONLY=$([ "$WASI_SDK_CI_COMPILER_RT_ONLY" = "1" ] && echo "ON" || echo "OFF") \
   "-DCMAKE_INSTALL_PREFIX=$build_dir/install"
 ninja -C $build_dir/sysroot install dist -v
 

cmake/wasi-sdk-sysroot.cmake

@@ -30,6 +30,7 @@ option(WASI_SDK_INCLUDE_TESTS "Whether or not to build tests by default" OFF)
 option(WASI_SDK_INSTALL_TO_CLANG_RESOURCE_DIR "Whether or not to modify the compiler's resource directory" OFF)
 option(WASI_SDK_LTO "Whether or not to build LTO assets" ON)
 option(WASI_SDK_BUILD_SHARED "Whether or not to build shared libraries when supported" ON)
+option(WASI_SDK_COMPILER_RT_ONLY "Whether or not to build only compiler-rt" OFF)
 set(WASI_SDK_EXCEPTIONS "${EXCEPTIONS_DEFAULT}" CACHE STRING "Whether or not C++ exceptions are enabled")
 set(WASI_SDK_CPU_CFLAGS "-mcpu=lime1" CACHE STRING "CFLAGS to specify wasm features to enable")
 
@@ -440,7 +441,11 @@ endif()
 add_custom_target(build ALL)
 foreach(target IN LISTS WASI_SDK_TARGETS)
   add_custom_target(build-${target})
-  add_dependencies(build-${target} libcxx-${target} wasi-libc-${target} compiler-rt)
+  if (WASI_SDK_COMPILER_RT_ONLY)
+    add_dependencies(build-${target} compiler-rt)
+  else()
+    add_dependencies(build-${target} libcxx-${target} wasi-libc-${target} compiler-rt)
+  endif()
   add_dependencies(build build-${target})
 endforeach()