ci: run Windows argument-comment-lint via native Bazel

Author: bolinfest

.bazelrc

@@ -81,6 +81,10 @@ build:clippy --@rules_rust//rust/settings:clippy.toml=//codex-rs:clippy.toml
 build:argument-comment-lint --aspects=//tools/argument-comment-lint:lint_aspect.bzl%rust_argument_comment_lint_aspect
 build:argument-comment-lint --output_groups=argument_comment_lint_checks
 build:argument-comment-lint --@rules_rust//rust/toolchain/channel=nightly
+# On Windows, exec-side helper binaries such as process_wrapper need to prefer
+# rust-lld over the GNU-flavored Bazel C++ linker path.
+build:argument-comment-lint-windows --config=argument-comment-lint
+build:argument-comment-lint-windows --@rules_rust//rust/settings:toolchain_linker_preference=rust
 
 # Rearrange caches on Windows so they're on the same volume as the checkout.
 common:ci-windows --config=ci-bazel

.github/actions/setup-bazel-ci/action.yml

@@ -60,8 +60,15 @@ runs:
         # Use the shortest available drive to reduce argv/path length issues,
         # but avoid the drive root because some Windows test launchers mis-handle
         # MANIFEST paths there.
-        $bazelOutputUserRoot = if (Test-Path 'D:\') { 'D:\b' } else { 'C:\b' }
+        $hasDDrive = Test-Path 'D:\'
+        $bazelOutputUserRoot = if ($hasDDrive) { 'D:\b' } else { 'C:\b' }
+        $repoContentsCache = Join-Path $env:RUNNER_TEMP "bazel-repo-contents-cache-$env:GITHUB_RUN_ID-$env:GITHUB_JOB"
         "BAZEL_OUTPUT_USER_ROOT=$bazelOutputUserRoot" | Out-File -FilePath $env:GITHUB_ENV -Encoding utf8 -Append
+        "BAZEL_REPO_CONTENTS_CACHE=$repoContentsCache" | Out-File -FilePath $env:GITHUB_ENV -Encoding utf8 -Append
+        if (-not $hasDDrive) {
+          $repositoryCache = Join-Path $env:USERPROFILE '.cache\bazel-repo-cache'
+          "BAZEL_REPOSITORY_CACHE=$repositoryCache" | Out-File -FilePath $env:GITHUB_ENV -Encoding utf8 -Append
+        }
 
     - name: Enable Git long paths (Windows)
       if: runner.os == 'Windows'

.github/scripts/run-bazel-ci.sh

@@ -126,6 +126,17 @@ if [[ $remote_download_toplevel -eq 1 ]]; then
   post_config_bazel_args+=(--remote_download_toplevel)
 fi
 
+if [[ -n "${BAZEL_REPO_CONTENTS_CACHE:-}" ]]; then
+  # Windows self-hosted runners can run multiple Bazel jobs concurrently. Give
+  # each job its own repo contents cache so they do not fight over the shared
+  # path configured in `ci-windows`.
+  post_config_bazel_args+=("--repo_contents_cache=${BAZEL_REPO_CONTENTS_CACHE}")
+fi
+
+if [[ -n "${BAZEL_REPOSITORY_CACHE:-}" ]]; then
+  post_config_bazel_args+=("--repository_cache=${BAZEL_REPOSITORY_CACHE}")
+fi
+
 bazel_console_log="$(mktemp)"
 trap 'rm -f "$bazel_console_log"' EXIT
 

.github/workflows/rust-ci-full.yml

@@ -100,6 +100,9 @@ jobs:
           sudo DEBIAN_FRONTEND=noninteractive apt-get update
           sudo DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends pkg-config libcap-dev
       - name: Run argument comment lint on codex-rs via Bazel
+        if: ${{ runner.os != 'Windows' }}
+        env:
+          BUILDBUDDY_API_KEY: ${{ secrets.BUILDBUDDY_API_KEY }}
         shell: bash
         run: |
           ./.github/scripts/run-bazel-ci.sh \
@@ -110,6 +113,23 @@ jobs:
             --build_metadata=COMMIT_SHA=${GITHUB_SHA} \
             -- \
             //codex-rs/...
+      - name: Run argument comment lint on codex-rs via Bazel
+        if: ${{ runner.os == 'Windows' }}
+        env:
+          BUILDBUDDY_API_KEY: ${{ secrets.BUILDBUDDY_API_KEY }}
+        shell: bash
+        run: |
+          ./.github/scripts/run-bazel-ci.sh \
+            -- \
+            build \
+            --config=argument-comment-lint-windows \
+            --host_platform=//:local_windows_msvc \
+            --platforms=//:local_windows \
+            --extra_execution_platforms=//:local_windows \
+            --keep_going \
+            --build_metadata=COMMIT_SHA=${GITHUB_SHA} \
+            -- \
+            //codex-rs/...
 
   # --- CI to validate on different os/targets --------------------------------
   lint_build:

.github/workflows/rust-ci.yml

@@ -159,17 +159,6 @@ jobs:
         run: |
           sudo DEBIAN_FRONTEND=noninteractive apt-get update
           sudo DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends pkg-config libcap-dev
-      - name: Install nightly argument-comment-lint toolchain
-        if: ${{ runner.os == 'Windows' }}
-        shell: bash
-        run: |
-          rustup toolchain install nightly-2025-09-18 \
-            --profile minimal \
-            --component llvm-tools-preview \
-            --component rustc-dev \
-            --component rust-src \
-            --no-self-update
-          rustup default nightly-2025-09-18
       - name: Run argument comment lint on codex-rs via Bazel
         if: ${{ runner.os != 'Windows' }}
         env:
@@ -184,10 +173,23 @@ jobs:
             --build_metadata=COMMIT_SHA=${GITHUB_SHA} \
             -- \
             //codex-rs/...
-      - name: Run argument comment lint on codex-rs via packaged wrapper
+      - name: Run argument comment lint on codex-rs via Bazel
         if: ${{ runner.os == 'Windows' }}
+        env:
+          BUILDBUDDY_API_KEY: ${{ secrets.BUILDBUDDY_API_KEY }}
         shell: bash
-        run: python3 ./tools/argument-comment-lint/run-prebuilt-linter.py
+        run: |
+          ./.github/scripts/run-bazel-ci.sh \
+            -- \
+            build \
+            --config=argument-comment-lint-windows \
+            --host_platform=//:local_windows_msvc \
+            --platforms=//:local_windows \
+            --extra_execution_platforms=//:local_windows \
+            --keep_going \
+            --build_metadata=COMMIT_SHA=${GITHUB_SHA} \
+            -- \
+            //codex-rs/...
 
   # --- Gatherer job that you mark as the ONLY required status -----------------
   results:

BUILD.bazel

@@ -17,12 +17,19 @@ platform(
 platform(
     name = "local_windows",
     constraint_values = [
-        # We just need to pick one of the ABIs. Do the same one we target.
         "@rules_rs//rs/experimental/platforms/constraints:windows_gnullvm",
     ],
     parents = ["@platforms//host"],
 )
 
+platform(
+    name = "local_windows_msvc",
+    constraint_values = [
+        "@rules_rs//rs/experimental/platforms/constraints:windows_msvc",
+    ],
+    parents = ["@platforms//host"],
+)
+
 alias(
     name = "rbe",
     actual = "@rbe_platform",

MODULE.bazel

@@ -82,6 +82,7 @@ rules_rust = use_extension("@rules_rs//rs/experimental:rules_rust.bzl", "rules_r
 rules_rust.patch(
     patches = [
         "//patches:rules_rust_windows_gnullvm_build_script.patch",
+        "//patches:rules_rust_repository_set_exec_constraints.patch",
     ],
     strip = 1,
 )
@@ -96,6 +97,34 @@ nightly_rust.toolchain(
     dev_components = True,
     edition = "2024",
 )
+# Keep Windows exec tools on MSVC so Bazel helper binaries link correctly, but
+# lint crate targets as `windows-gnullvm` to preserve the repo's actual cfgs.
+nightly_rust.repository_set(
+    name = "rust_windows_x86_64",
+    edition = "2024",
+    exec_triple = "x86_64-pc-windows-msvc",
+    exec_compatible_with = [
+        "@platforms//cpu:x86_64",
+        "@platforms//os:windows",
+        "@rules_rs//rs/experimental/platforms/constraints:windows_msvc",
+    ],
+    target_compatible_with = [
+        "@platforms//cpu:x86_64",
+        "@platforms//os:windows",
+        "@rules_rs//rs/experimental/platforms/constraints:windows_msvc",
+    ],
+    target_triple = "x86_64-pc-windows-msvc",
+    versions = ["nightly/2025-09-18"],
+)
+nightly_rust.repository_set(
+    name = "rust_windows_x86_64",
+    target_compatible_with = [
+        "@platforms//cpu:x86_64",
+        "@platforms//os:windows",
+        "@rules_rs//rs/experimental/platforms/constraints:windows_gnullvm",
+    ],
+    target_triple = "x86_64-pc-windows-gnullvm",
+)
 use_repo(nightly_rust, "rust_toolchains")
 
 toolchains = use_extension("@rules_rs//rs/experimental/toolchains:module_extension.bzl", "toolchains")

patches/BUILD.bazel

@@ -2,6 +2,7 @@ exports_files([
     "abseil_windows_gnullvm_thread_identity.patch",
     "aws-lc-sys_memcmp_check.patch",
     "llvm_windows_symlink_extract.patch",
+    "rules_rust_repository_set_exec_constraints.patch",
     "rules_rust_windows_gnullvm_build_script.patch",
     "rules_rs_windows_gnullvm_exec.patch",
     "rusty_v8_prebuilt_out_dir.patch",

patches/rules_rust_repository_set_exec_constraints.patch

@@ -0,0 +1,26 @@
+# What: let `rules_rust` repository_set entries specify an explicit exec-platform
+# constraint set.
+# Why: codex needs Windows nightly lint toolchains to run helper binaries on an
+# MSVC exec platform while still targeting `windows-gnullvm` crates.
+
+diff --git a/rust/extensions.bzl b/rust/extensions.bzl
+--- a/rust/extensions.bzl
++++ b/rust/extensions.bzl
+@@ -52,6 +52,7 @@ def _rust_impl(module_ctx):
+                 "allocator_library": repository_set.allocator_library,
+                 "dev_components": repository_set.dev_components,
+                 "edition": repository_set.edition,
++                "exec_compatible_with": [str(v) for v in repository_set.exec_compatible_with] if repository_set.exec_compatible_with else None,
+                 "exec_triple": repository_set.exec_triple,
+                 "extra_target_triples": {repository_set.target_triple: [str(v) for v in repository_set.target_compatible_with]},
+                 "name": repository_set.name,
+@@ -166,6 +167,9 @@ _COMMON_TAG_KWARGS = {
+ 
+ _RUST_REPOSITORY_SET_TAG_ATTRS = {
++    "exec_compatible_with": attr.label_list(
++        doc = "Execution platform constraints for this repository_set.",
++    ),
+     "exec_triple": attr.string(
+         doc = "Exec triple for this repository_set.",
+     ),
+     "name": attr.string(