Implement latest requirements

.github/workflows/tests.yml

@@ -41,6 +41,22 @@ jobs:
           USE_BAZEL_VERSION: ${{ matrix.bazel_version }}
           USE_BZLMOD: ${{ matrix.bzlmod }}
         run: tests/scripts/run_tests.sh
+  toolchain_test:
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [macos-latest, ubuntu-latest]
+        # TODO: Test with Bazel 8 after https://github.com/bazelbuild/bazel/pull/24154 has been released.
+        bazel_version: [7.x, latest] # Minimum supported Bazel version is 7.x
+        bzlmod: [true, false]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - uses: actions/checkout@v4
+      - name: Test
+        env:
+          USE_BAZEL_VERSION: ${{ matrix.bazel_version }}
+          USE_BZLMOD: ${{ matrix.bzlmod }}
+        run: tests/scripts/run_toolchain_tests.sh
   external_test:
     strategy:
       fail-fast: false

MODULE.bazel

@@ -22,6 +22,7 @@ module(
 bazel_dep(name = "bazel_skylib", version = "1.5.0")
 bazel_dep(name = "rules_cc", version = "0.0.17")
 bazel_dep(name = "platforms", version = "0.0.8")
+bazel_dep(name = "helly25_bzl", version = "0.1.2")
 
 # TODO: Remove when protobuf is released with a version of rules_python that supports 8.x
 bazel_dep(name = "rules_python", version = "1.0.0", dev_dependency = True)

WORKSPACE

@@ -15,3 +15,12 @@
 workspace(
     name = "toolchains_llvm",
 )
+
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+
+http_archive(
+    name = "helly25_bzl",
+    sha256 = "404f8473bcaad2e370752e57d274d2093eb87ca94cb9a597c1a3553b76743206",
+    strip_prefix = "bzl-0.1.2",
+    url = "https://github.com/helly25/bzl/releases/download/0.1.2/bzl-0.1.2.tar.gz",
+)

tests/scripts/run_toolchain_tests.sh

@@ -0,0 +1,45 @@
+#!/bin/bash
+# Copyright 2018 The Bazel Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -euo pipefail
+
+while getopts "h" opt; do
+  case "${opt}" in
+  "h")
+    echo "Usage: No options"
+    exit 2
+    ;;
+  *)
+    echo "invalid option: -${OPTARG}"
+    exit 1
+    ;;
+  esac
+done
+
+scripts_dir="$(dirname "${BASH_SOURCE[0]}")"
+source "${scripts_dir}/bazel.sh"
+"${bazel}" version
+
+set -x
+test_args=(
+  "--check_direct_dependencies=off"
+)
+
+targets=(
+  "//toolchain/..."
+)
+
+"${bazel}" ${TEST_MIGRATION:+"--strict"} --bazelrc=/dev/null test \
+  "${common_test_args[@]}" "${test_args[@]}" "${targets[@]}"

toolchain/deps.bzl

@@ -35,4 +35,12 @@ def bazel_toolchain_dependencies():
             sha256 = "bc283cdfcd526a52c3201279cda4bc298652efa898b10b4db0837dc51652756f",
         )
 
-        # Skip bazel_skylib_workspace because we are not using lib/unittest.bzl
+    # Skip bazel_skylib_workspace because we are not using lib/unittest.bzl
+
+    if not native.existing_rule("helly25_bzl"):
+        http_archive(
+            name = "helly25_bzl",
+            strip_prefix = "bzl-0.1.2",
+            url = "https://github.com/helly25/bzl/releases/download/0.1.2/bzl-0.1.2.tar.gz",
+            sha256 = "404f8473bcaad2e370752e57d274d2093eb87ca94cb9a597c1a3553b76743206",
+        )

toolchain/internal/BUILD.bazel

@@ -12,4 +12,31 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+load("@bazel_skylib//rules:diff_test.bzl", "diff_test")
+load("llvm_distributions.bzl", "distributions_test_writer", "requirements_test_writer")
+
 exports_files(["template.modulemap"])
+
+distributions_test_writer(
+    name = "llvm_distributions_test_output",
+    testonly = True,
+    visibility = ["//visibility:private"],
+)
+
+requirements_test_writer(
+    name = "llvm_requirements_test_output",
+    testonly = True,
+    visibility = ["//visibility:private"],
+)
+
+diff_test(
+    name = "llvm_distributions_test",
+    file1 = "llvm_distributions_test.golden.txt",
+    file2 = "llvm_distributions_test_output",
+)
+
+diff_test(
+    name = "llvm_requirements_test",
+    file1 = "llvm_requirements_test.golden.txt",
+    file2 = "llvm_requirements_test_output",
+)

toolchain/internal/configure.bzl

@@ -36,6 +36,10 @@ load(
     _supported_targets = "SUPPORTED_TARGETS",
     _toolchain_tools = "toolchain_tools",
 )
+load(
+    "//toolchain/internal:llvm_distributions.bzl",
+    _latest_llvm_release_name_or_fail = "latest_llvm_release_name_or_fail",
+)
 load(
     "//toolchain/internal:sysroot.bzl",
     _default_sysroot_path = "default_sysroot_path",
@@ -79,6 +83,13 @@ def llvm_config_impl(rctx):
     if not toolchain_root:
         fail("LLVM toolchain root missing for ({}, {})".format(os, arch))
     (_key, llvm_version) = _exec_os_arch_dict_value(rctx, "llvm_versions")
+    if llvm_version.startswith("latest"):
+        (llvm_version, distribution) = _latest_llvm_release_name_or_fail(rctx, llvm_version)
+        if llvm_version:
+            print("\nINFO: Resolved latest LLVM version to {llvm_version}: {distribution}".format(
+                distribution = distribution,
+                llvm_version = llvm_version,
+            ))  # buildifier: disable=print
     if not llvm_version:
         # LLVM version missing for (os, arch)
         _empty_repository(rctx)