unix: use pre-built Clang toolchains

Waiting for clang to build has historically been a pain point with
this project. Especially on Linux, where we first have to build
GCC in order to build clang. Building clang slows down local builds.
It slows down CI. It makes pull requests time out because sccache
isn't populated (since it requires credentials to speak to an S3
bucket).

I have broken out the building of Clang into its own project. This
commit deletes the code for building Clang from source and replaces
it with functionality for downloading a pre-built Clang. Because
we only built GCC to build Clang, functionality for building GCC
has also been deleted.

Author: indygreg

.github/workflows/apple.yml

@@ -34,45 +34,6 @@ jobs:
           name: pythonbuild
           path: target/release/pythonbuild
 
-  toolchain:
-    runs-on: 'macos-11'
-    env:
-      AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
-      AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
-      SCCACHE_BUCKET: 'python-build-standalone-sccache'
-      SCCACHE_S3_USE_SSL: '1'
-      SCCACHE_IDLE_TIMEOUT: '0'
-    steps:
-      - uses: actions/checkout@v3
-
-      - name: Install Python
-        uses: actions/setup-python@v2
-        with:
-          python-version: '3.9'
-
-      - name: Install sccache
-        run: |
-          curl --location --insecure https://github.com/mozilla/sccache/releases/download/v0.3.0/sccache-v0.3.0-x86_64-apple-darwin.tar.gz > sccache.tar.gz
-          echo "61c16fd36e32cdc923b66e4f95cb367494702f60f6d90659af1af84c3efb11eb  sccache.tar.gz" | shasum -a 256 -c
-          tar -xvf sccache.tar.gz
-          mv sccache-*/sccache .
-          chmod +x sccache
-          ./sccache --start-server
-
-      - name: Build
-        run: |
-          python3.9 ./build-macos.py --make-target toolchain
-
-      - name: Stop sccache
-        run: |
-          ./sccache -s
-
-      - name: Upload Toolchain Archive
-        uses: actions/upload-artifact@v3
-        with:
-          name: toolchain
-          path: build/clang-*.tar
-
   build:
     strategy:
       fail-fast: false
@@ -177,7 +138,6 @@ jobs:
             optimizations: 'lto'
     needs:
       - pythonbuild
-      - toolchain
     runs-on: 'macos-11'
     steps:
       - uses: actions/checkout@v3
@@ -195,12 +155,6 @@ jobs:
           name: pythonbuild
           path: build
 
-      - name: Download toolchain
-        uses: actions/download-artifact@v3
-        with:
-          name: toolchain
-          path: build
-
       - name: Build
         run: |
           export APPLE_HOST_SDK_PATH=/Applications/Xcode_12.5.1.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX11.3.sdk
@@ -218,7 +172,7 @@ jobs:
             exit 1
           fi
 
-          ./build-macos.py --skip-toolchain --target-triple ${{ matrix.build.target_triple }} --python ${{ matrix.build.py }} --optimizations ${{ matrix.build.optimizations }}
+          ./build-macos.py --target-triple ${{ matrix.build.target_triple }} --python ${{ matrix.build.py }} --optimizations ${{ matrix.build.optimizations }}
 
       - uses: actions/checkout@v3
         with:

.github/workflows/linux.yml

@@ -39,45 +39,6 @@ jobs:
           name: pythonbuild
           path: target/release/pythonbuild
 
-  toolchain:
-    runs-on: 'ubuntu-20.04'
-    env:
-      AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
-      AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
-      SCCACHE_BUCKET: 'python-build-standalone-sccache'
-      SCCACHE_S3_USE_SSL: '1'
-      SCCACHE_IDLE_TIMEOUT: '0'
-    steps:
-      - uses: actions/checkout@v3
-
-      - name: Install Python
-        uses: actions/setup-python@v2
-        with:
-          python-version: '3.9'
-
-      - name: Install sccache
-        run: |
-          curl --location --insecure https://github.com/mozilla/sccache/releases/download/v0.3.0/sccache-v0.3.0-x86_64-unknown-linux-musl.tar.gz > sccache.tar.gz
-          echo "e6cd8485f93d683a49c83796b9986f090901765aa4feb40d191b03ea770311d8  sccache.tar.gz" | sha256sum -c
-          tar -xvf sccache.tar.gz
-          mv sccache-*/sccache .
-          chmod +x sccache
-          ./sccache --start-server
-
-      - name: Build
-        run: |
-          python3.9 ./build-linux.py --make-target toolchain
-
-      - name: Stop sccache
-        run: |
-          ./sccache -s
-
-      - name: Upload Toolchain Archive
-        uses: actions/upload-artifact@v3
-        with:
-          name: toolchain
-          path: build/*.tar
-
   build:
     strategy:
       fail-fast: false
@@ -456,7 +417,6 @@ jobs:
 
     needs:
       - pythonbuild
-      - toolchain
     runs-on: 'ubuntu-20.04'
     steps:
       - uses: actions/checkout@v3
@@ -474,15 +434,9 @@ jobs:
           name: pythonbuild
           path: build
 
-      - name: Download toolchain
-        uses: actions/download-artifact@v3
-        with:
-          name: toolchain
-          path: build
-
       - name: Build
         run: |
-          ./build-linux.py --skip-toolchain --target-triple ${{ matrix.build.target_triple }} --python ${{ matrix.build.py }} --optimizations ${{ matrix.build.optimizations }}
+          ./build-linux.py --target-triple ${{ matrix.build.target_triple }} --python ${{ matrix.build.py }} --optimizations ${{ matrix.build.optimizations }}
 
       - name: Validate Distribution
         run: |

cpython-unix/Makefile

@@ -50,8 +50,7 @@ $(shell $(RUN_BUILD) placeholder_archive dockerfiles)
 
 BASE_TOOLCHAIN_DEPENDS := \
     $(if $(NEED_BINUTILS),$(OUTDIR)/binutils-$(BINUTILS_VERSION)-$(HOST_PLATFORM).tar) \
-    $(if $(NEED_GCC),$(OUTDIR)/gcc-$(GCC_VERSION)-$(HOST_PLATFORM).tar) \
-    $(OUTDIR)/clang-$(CLANG_VERSION)-$(HOST_PLATFORM).tar \
+    $(OUTDIR)/$(CLANG_FILENAME) \
     $(NULL)
 
 TOOLCHAIN_DEPENDS := \
@@ -62,7 +61,7 @@ TOOLCHAIN_DEPENDS := \
 PYTHON_DEP_DEPENDS := \
     $(OUTDIR)/targets/$(TARGET_TRIPLE) \
     $(if $(PYBUILD_NO_DOCKER),,$(OUTDIR)/image-$(DOCKER_IMAGE_BUILD).tar) \
-    $(if $(PYBUILD_SKIP_TOOLCHAIN),,$(TOOLCHAIN_DEPENDS)) \
+    $(TOOLCHAIN_DEPENDS) \
     $(NULL)
 
 default: $(OUTDIR)/cpython-$(PYBUILD_PYTHON_VERSION)-$(PACKAGE_SUFFIX).tar
@@ -75,28 +74,7 @@ endif
 $(OUTDIR)/binutils-$(BINUTILS_VERSION)-$(HOST_PLATFORM).tar: $(OUTDIR)/image-gcc.tar $(HERE)/build-binutils.sh
 	$(RUN_BUILD) --toolchain binutils
 
-GCC_DEPENDS := \
-    $(OUTDIR)/binutils-$(BINUTILS_VERSION)-$(HOST_PLATFORM).tar \
-    $(OUTDIR)/versions/VERSION.gmp \
-    $(OUTDIR)/versions/VERSION.isl \
-    $(OUTDIR)/versions/VERSION.mpc \
-    $(OUTDIR)/versions/VERSION.mpfr \
-    $(HERE)/build-gcc.sh \
-    $(NULL)
-
-$(OUTDIR)/gcc-$(GCC_VERSION)-$(HOST_PLATFORM).tar: $(GCC_DEPENDS)
-	$(RUN_BUILD) --toolchain gcc
-
-CLANG_DEPENDS := \
-    $(if $(NEED_BINUTILS),$(OUTDIR)/binutils-$(BINUTILS_VERSION)-$(HOST_PLATFORM).tar) \
-    $(if $(NEED_GCC),$(OUTDIR)/gcc-$(GCC_VERSION)-$(HOST_PLATFORM).tar) \
-    $(if $(PYBUILD_NO_DOCKER),,$(OUTDIR)/image-clang.tar) \
-    $(OUTDIR)/versions/VERSION.cmake-linux-bin \
-    $(OUTDIR)/versions/VERSION.cmake-macos-bin \
-    $(HERE)/build-clang-$(HOST_PLATFORM).sh \
-    $(NULL)
-
-$(OUTDIR)/clang-$(CLANG_VERSION)-$(HOST_PLATFORM).tar: $(CLANG_DEPENDS)
+$(OUTDIR)/$(CLANG_FILENAME):
 	$(RUN_BUILD) --toolchain clang
 
 $(OUTDIR)/musl-$(MUSL_VERSION)-$(HOST_PLATFORM).tar: $(BASE_TOOLCHAIN_DEPENDS) $(HERE)/build-musl.sh
@@ -105,7 +83,7 @@ $(OUTDIR)/musl-$(MUSL_VERSION)-$(HOST_PLATFORM).tar: $(BASE_TOOLCHAIN_DEPENDS) $
 ifeq ($(HOST_PLATFORM),linux64)
     TOOLCHAIN_TARGET := $(OUTDIR)/musl-$(MUSL_VERSION)-$(HOST_PLATFORM).tar
 else
-    TOOLCHAIN_TARGET := $(OUTDIR)/clang-$(CLANG_VERSION)-$(HOST_PLATFORM).tar
+    TOOLCHAIN_TARGET :=
 endif
 
 toolchain: $(TOOLCHAIN_TARGET)