[Github] Use building LLVM as perf-training for CI container

.github/workflows/build-ci-container.yml

@@ -1,4 +1,3 @@
-
 name: Build CI Container
 
 permissions:
@@ -19,9 +18,41 @@ on:
       - '.github/workflows/containers/github-action-ci/**'
 
 jobs:
-  build-ci-container:
+  # TODO(boomanaiden154): Switch this back to a single stage build when we can
+  # run this on the self-hosted runners and don't have to do it this way to
+  # avoid timeouts.
+  build-ci-container-stage1:
     if: github.repository_owner == 'llvm'
     runs-on: ubuntu-latest
+    steps:
+      - name: Checkout LLVM
+        uses: actions/checkout@v4
+        with:
+          sparse-checkout: .github/workflows/containers/github-action-ci/
+      - name: Change podman Root Direcotry
+        run: |
+          mkdir -p ~/.config/containers
+          sudo mkdir -p /mnt/podman
+          sudo chown `whoami`:`whoami` /mnt/podman
+          cp ./.github/workflows/containers/github-action-ci/storage.conf ~/.config/containers/storage.conf
+          podman info
+      - name: Build container stage1
+        working-directory: ./.github/workflows/containers/github-action-ci/
+        run: |
+          podman build -t stage1-toolchain --target stage1-toolchain -f stage1.Dockerfile .
+      - name: Save container image
+        run: |
+          podman save stage1-toolchain > stage1-toolchain.tar
+      - name: Upload container image
+        uses: actions/upload-artifact@v4
+        with:
+          name: stage1-toolchain
+          path: stage1-toolchain.tar
+          retention-days: 1
+  build-ci-container-stage2:
+    if: github.repository_owner == 'llvm'
+    runs-on: ubuntu-latest
+    needs: build-ci-container-stage1
     permissions:
       packages: write
     steps:
@@ -38,10 +69,27 @@ jobs:
         with:
           sparse-checkout: .github/workflows/containers/github-action-ci/
 
+      - name: Change podman Root Direcotry
+        run: |
+          mkdir -p ~/.config/containers
+          sudo mkdir -p /mnt/podman
+          sudo chown `whoami`:`whoami` /mnt/podman
+          cp ./.github/workflows/containers/github-action-ci/storage.conf ~/.config/containers/storage.conf
+          podman info
+
+      - name: Download stage1-toolchain
+        uses: actions/download-artifact@v4
+        with:
+          name: stage1-toolchain
+
+      - name: Load stage1-toolchain
+        run: |
+          podman load -i stage1-toolchain.tar
+
       - name: Build Container
         working-directory: ./.github/workflows/containers/github-action-ci/
         run: |
-          podman build -t ${{ steps.vars.outputs.container-name-tag }} .
+          podman build -t ${{ steps.vars.outputs.container-name-tag }} -f stage2.Dockerfile .
           podman tag ${{ steps.vars.outputs.container-name-tag }} ${{ steps.vars.outputs.container-name }}:latest
 
       - name: Test Container

.github/workflows/containers/github-action-ci/bootstrap.patch

@@ -0,0 +1,13 @@
+diff --git a/clang/cmake/caches/BOLT-PGO.cmake b/clang/cmake/caches/BOLT-PGO.cmake
+index 1a04ca9a74e5..d092820e4115 100644
+--- a/clang/cmake/caches/BOLT-PGO.cmake
++++ b/clang/cmake/caches/BOLT-PGO.cmake
+@@ -4,6 +4,8 @@ set(CLANG_BOOTSTRAP_TARGETS
+   stage2-clang-bolt
+   stage2-distribution
+   stage2-install-distribution
++  clang
++  lld
+   CACHE STRING "")
+ set(BOOTSTRAP_CLANG_BOOTSTRAP_TARGETS
+   clang-bolt

.github/workflows/containers/github-action-ci/stage1.Dockerfile

@@ -0,0 +1,44 @@
+FROM docker.io/library/ubuntu:22.04 as base
+ENV LLVM_SYSROOT=/opt/llvm
+
+FROM base as stage1-toolchain
+ENV LLVM_VERSION=17.0.6
+
+RUN apt-get update && \
+    apt-get install -y \
+    wget \
+    gcc \
+    g++ \
+    cmake \
+    ninja-build \
+    python3 \
+    git \
+    curl
+
+RUN curl -O -L https://github.com/llvm/llvm-project/archive/refs/tags/llvmorg-$LLVM_VERSION.tar.gz && tar -xf llvmorg-$LLVM_VERSION.tar.gz
+
+WORKDIR /llvm-project-llvmorg-$LLVM_VERSION
+
+COPY bootstrap.patch /
+
+# TODO(boomanaiden154): Remove the patch pulled from a LLVM PR once we bump
+# the toolchain to version 18 and the patch is in-tree.
+# TODO(boomanaiden154): Remove the bootstrap patch once we unsplit the build
+# and no longer need to explicitly build the stage2 dependencies.
+RUN curl https://github.com/llvm/llvm-project/commit/dd0356d741aefa25ece973d6cc4b55dcb73b84b4.patch | patch -p1 && cat /bootstrap.patch | patch -p1
+
+RUN mkdir build
+
+RUN cmake -B ./build -G Ninja ./llvm \
+  -C ./clang/cmake/caches/BOLT-PGO.cmake \
+  -DBOOTSTRAP_LLVM_ENABLE_LLD=ON \
+  -DBOOTSTRAP_BOOTSTRAP_LLVM_ENABLE_LLD=ON \
+  -DPGO_INSTRUMENT_LTO=Thin \
+  -DLLVM_ENABLE_RUNTIMES="compiler-rt" \
+  -DCMAKE_INSTALL_PREFIX="$LLVM_SYSROOT" \
+  -DLLVM_ENABLE_PROJECTS="bolt;clang;lld;clang-tools-extra" \
+  -DLLVM_DISTRIBUTION_COMPONENTS="lld;compiler-rt;clang-format" \
+  -DCLANG_DEFAULT_LINKER="lld" \
+  -DBOOTSTRAP_CLANG_PGO_TRAINING_DATA_SOURCE_DIR=/llvm-project-llvmorg-$LLVM_VERSION/llvm
+
+RUN ninja -C ./build stage2-instrumented-clang stage2-instrumented-lld

.github/workflows/containers/github-action-ci/stage2.Dockerfile

@@ -0,0 +1,27 @@
+FROM docker.io/library/ubuntu:22.04 as base
+ENV LLVM_SYSROOT=/opt/llvm
+
+FROM stage1-toolchain AS stage2-toolchain
+
+RUN ninja -C ./build stage2-clang-bolt stage2-install-distribution && ninja -C ./build install-distribution && rm -rf ./build
+
+FROM base
+
+COPY --from=stage2-toolchain $LLVM_SYSROOT $LLVM_SYSROOT
+
+# Need to install curl for hendrikmuhs/ccache-action
+# Need nodejs for some of the GitHub actions.
+# Need perl-modules for clang analyzer tests.
+RUN apt-get update && \
+    apt-get install -y \
+    binutils \
+    cmake \
+    curl \
+    libstdc++-11-dev \
+    ninja-build \
+    nodejs \
+    perl-modules \
+    python3-psutil
+
+ENV LLVM_SYSROOT=$LLVM_SYSROOT
+ENV PATH=${LLVM_SYSROOT}/bin:${PATH}

.github/workflows/containers/github-action-ci/storage.conf

@@ -0,0 +1,4 @@
+[storage]
+  driver = "overlay"
+  runroot = "/mnt/podman/container"
+  graphroot = "/mnt/podman/image"