From e609b3518346a5984eb41fb769132d79e63c27ea Mon Sep 17 00:00:00 2001
From: Felix Hanau <felix@cloudflare.com>
Date: Wed, 10 Jan 2024 14:26:21 -0500
Subject: [PATCH] Explore using higher LLVM, MSVC, Xcode versions

- Compile with LLVM 21 on Linux (we do not expect to upgrade beyond 19 anytime
  soon).
- Use latest MSVC
---
 .github/actions/setup-runner/action.yml | 38 +++++++++++++------------
 .github/workflows/test.yml              |  4 +--
 build/ci.bazelrc                        |  4 +--
 3 files changed, 24 insertions(+), 22 deletions(-)

diff --git a/.github/actions/setup-runner/action.yml b/.github/actions/setup-runner/action.yml
index 45b8fb23928..74fe9095b29 100644
--- a/.github/actions/setup-runner/action.yml
+++ b/.github/actions/setup-runner/action.yml
@@ -11,26 +11,26 @@ runs:
         wget https://apt.llvm.org/llvm.sh
         sed -i '/apt-get install/d' llvm.sh
         chmod +x llvm.sh
-        sudo ./llvm.sh 19
+        sudo ./llvm.sh 21
         # keep in sync with build/ci.bazelrc
         sudo apt-get install -y -qq --no-install-recommends \
-          clang-19 \
-          lld-19 \
-          libunwind-19 \
-          libc++abi1-19 \
-          libc++1-19 \
-          libc++-19-dev \
-          libclang-rt-19-dev \
-          llvm-19
-        sudo ln -s /usr/bin/llvm-symbolizer-19 /usr/bin/llvm-symbolizer
-        sudo ln -s /usr/bin/llvm-profdata-19 /usr/bin/llvm-profdata
-        sudo ln -s /usr/bin/llvm-cov-19 /usr/bin/llvm-cov
-        echo "build:linux --action_env=CC=/usr/lib/llvm-19/bin/clang" >> .bazelrc
-        echo "build:linux --host_action_env=CC=/usr/lib/llvm-19/bin/clang" >> .bazelrc
-        echo "build:linux --linkopt=--ld-path=/usr/lib/llvm-19/bin/ld.lld" >> .bazelrc
-        echo "build:linux --host_linkopt=--ld-path=/usr/lib/llvm-19/bin/ld.lld" >> .bazelrc
-        echo "build:linux --action_env=AR=/usr/lib/llvm-19/bin/llvm-ar" >> .bazelrc
-        echo "build:linux --host_action_env=AR=/usr/lib/llvm-19/bin/llvm-ar" >> .bazelrc
+          clang-21 \
+          lld-21 \
+          libunwind-21 \
+          libc++abi1-21 \
+          libc++1-21 \
+          libc++-21-dev \
+          libclang-rt-21-dev \
+          llvm-21
+        sudo ln -s /usr/bin/llvm-symbolizer-21 /usr/bin/llvm-symbolizer
+        sudo ln -s /usr/bin/llvm-profdata-21 /usr/bin/llvm-profdata
+        sudo ln -s /usr/bin/llvm-cov-21 /usr/bin/llvm-cov
+        echo "build:linux --action_env=CC=/usr/lib/llvm-21/bin/clang" >> .bazelrc
+        echo "build:linux --host_action_env=CC=/usr/lib/llvm-21/bin/clang" >> .bazelrc
+        echo "build:linux --linkopt=--ld-path=/usr/lib/llvm-21/bin/ld.lld" >> .bazelrc
+        echo "build:linux --host_linkopt=--ld-path=/usr/lib/llvm-21/bin/ld.lld" >> .bazelrc
+        echo "build:linux --action_env=AR=/usr/lib/llvm-21/bin/llvm-ar" >> .bazelrc
+        echo "build:linux --host_action_env=AR=/usr/lib/llvm-21/bin/llvm-ar" >> .bazelrc
     - name: Setup Windows
       shell: pwsh
       if: runner.os == 'Windows'
@@ -45,6 +45,8 @@ runs:
         git config --show-scope --show-origin core.symlinks
         git config --system core.longpaths true
         [System.IO.File]::WriteAllLines((Join-Path -Path $env:USERPROFILE -ChildPath '.bazelrc'), 'startup --output_user_root=\\\\?\\C:\\tmp')
+        # TODO: Test that the build is still compatible with the latest LLVM release
+        # choco upgrade llvm --version=21.1.8
     - name: Setup macOS
       if: runner.os == 'macOS'
       shell: bash
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 79d7f2c8d09..85abcf10134 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -36,7 +36,7 @@ jobs:
             { name: linux, arch: X64, image: ubuntu-22.04-16core },
             { name: linux-arm, arch: ARM64, image: ubuntu-22.04-arm-16core },
             { name: macOS, arch: ARM64, image: macos-15-xlarge, use_lld: true },
-            { name: windows, arch: X64, image: windows-2025-16core },
+            { name: windows, arch: X64, image: windows-2025-vs2026 },
           ]
         config: [
             # Default build: no suffix or additional bazel arguments
@@ -55,7 +55,7 @@ jobs:
           # - os:     { name : windows, image : windows-2025 }
           #   config: { suffix: -debug, bazel-args: --config=windows_dbg }
         exclude:
-          - os: { name: windows, arch: X64, image: windows-2025-16core }
+          - os: { name: windows, arch: X64, image: windows-2025-vs2026 }
             config: { suffix: -debug }
           # due to resource constraints, exclude the macOS and x64 Linux debug runners for now.
           # linux-asan and arm64 linux-debug should provide sufficient coverage for building in the
diff --git a/build/ci.bazelrc b/build/ci.bazelrc
index 1ae89a8d120..b7ee016b8d4 100644
--- a/build/ci.bazelrc
+++ b/build/ci.bazelrc
@@ -56,8 +56,8 @@ build:ci-linux-common --copt='-Werror'
 build:ci-linux-common --copt='-Wno-error=#warnings'
 build:ci-linux-common --copt='-Wno-error=deprecated-declarations'
 # keep in sync with .github/workflows/test.yml
-build:ci-linux-common --action_env=CC=/usr/lib/llvm-19/bin/clang
-build:ci-linux-common --host_action_env=CC=/usr/lib/llvm-19/bin/clang
+build:ci-linux-common --action_env=CC=/usr/lib/llvm-21/bin/clang
+build:ci-linux-common --host_action_env=CC=/usr/lib/llvm-21/bin/clang
 
 build:ci-linux --config=ci-linux-common --remote_download_regex=".*src/workerd/server/workerd.*"
 build:ci-linux-arm --config=ci-linux-common