[clang] [clang][deps] Implement efficient in-process `ModuleCache` (PR #129751)

Tue Mar 18 14:12:39 PDT 2025

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-cmake-x86_64-avx512-linux` running on `avx512-intel64` while building `clang` at step 6 "build stage 1".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/133/builds/13057

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 6 (build stage 1) failure: 'ninja' (failure)
...
[3178/4057] Building CXX object tools/clang/lib/Tooling/Inclusions/Stdlib/CMakeFiles/obj.clangToolingInclusionsStdlib.dir/StandardLibrary.cpp.o
[3179/4057] Linking CXX static library lib/libclangToolingInclusionsStdlib.a
[3180/4057] Building CXX object tools/clang/lib/Frontend/CMakeFiles/obj.clangFrontend.dir/ASTMerge.cpp.o
[3181/4057] Building CXX object tools/clang/lib/Tooling/Syntax/CMakeFiles/obj.clangToolingSyntax.dir/Nodes.cpp.o
[3182/4057] Building CXX object tools/clang/lib/Tooling/Refactoring/CMakeFiles/obj.clangToolingRefactoring.dir/Extract/SourceExtraction.cpp.o
[3183/4057] Building CXX object tools/clang/lib/Frontend/Rewrite/CMakeFiles/obj.clangRewriteFrontend.dir/RewriteObjC.cpp.o
[3184/4057] Building CXX object tools/clang/lib/Tooling/Syntax/CMakeFiles/obj.clangToolingSyntax.dir/Tree.cpp.o
[3185/4057] Building CXX object tools/clang/lib/Tooling/Refactoring/CMakeFiles/obj.clangToolingRefactoring.dir/ASTSelectionRequirements.cpp.o
[3186/4057] Building CXX object tools/clang/lib/Tooling/Syntax/CMakeFiles/obj.clangToolingSyntax.dir/ComputeReplacements.cpp.o
[3187/4057] Building CXX object tools/clang/lib/Tooling/DependencyScanning/CMakeFiles/obj.clangDependencyScanning.dir/DependencyScanningService.cpp.o
FAILED: tools/clang/lib/Tooling/DependencyScanning/CMakeFiles/obj.clangDependencyScanning.dir/DependencyScanningService.cpp.o 
/usr/bin/c++ -DCLANG_EXPORTS -DGTEST_HAS_RTTI=0 -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/stage1/tools/clang/lib/Tooling/DependencyScanning -I/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/clang/lib/Tooling/DependencyScanning -I/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/clang/include -I/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/stage1/tools/clang/include -I/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/stage1/include -I/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/llvm/include -march=cascadelake -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wno-uninitialized -Wno-nonnull -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wsuggest-override -Wno-comment -Wno-misleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -fno-common -Woverloaded-virtual -fno-strict-aliasing -O3 -DNDEBUG -std=c++17  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -MD -MT tools/clang/lib/Tooling/DependencyScanning/CMakeFiles/obj.clangDependencyScanning.dir/DependencyScanningService.cpp.o -MF tools/clang/lib/Tooling/DependencyScanning/CMakeFiles/obj.clangDependencyScanning.dir/DependencyScanningService.cpp.o.d -o tools/clang/lib/Tooling/DependencyScanning/CMakeFiles/obj.clangDependencyScanning.dir/DependencyScanningService.cpp.o -c /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/clang/lib/Tooling/DependencyScanning/DependencyScanningService.cpp
In file included from /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/clang/lib/Tooling/DependencyScanning/DependencyScanningService.cpp:9:
/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/clang/include/clang/Tooling/DependencyScanning/DependencyScanningService.h:117:22: error: declaration of ‘clang::tooling::dependencies::ModuleCacheMutexes clang::tooling::dependencies::DependencyScanningService::ModuleCacheMutexes’ changes meaning of ‘ModuleCacheMutexes’ [-fpermissive]
  117 |   ModuleCacheMutexes ModuleCacheMutexes;
      |                      ^~~~~~~~~~~~~~~~~~
In file included from /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/clang/include/clang/Tooling/DependencyScanning/DependencyScanningService.h:13,
                 from /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/clang/lib/Tooling/DependencyScanning/DependencyScanningService.cpp:9:
/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/clang/include/clang/Tooling/DependencyScanning/InProcessModuleCache.h:20:8: note: ‘ModuleCacheMutexes’ declared here as ‘struct clang::tooling::dependencies::ModuleCacheMutexes’
   20 | struct ModuleCacheMutexes {
      |        ^~~~~~~~~~~~~~~~~~
[3188/4057] Building CXX object tools/clang/lib/Frontend/CMakeFiles/obj.clangFrontend.dir/DependencyFile.cpp.o
[3189/4057] Building CXX object tools/clang/lib/Tooling/Syntax/CMakeFiles/obj.clangToolingSyntax.dir/TokenBufferTokenManager.cpp.o
[3190/4057] Building CXX object tools/clang/lib/Tooling/Refactoring/CMakeFiles/obj.clangToolingRefactoring.dir/Lookup.cpp.o
[3191/4057] Building CXX object tools/clang/lib/Tooling/DependencyScanning/CMakeFiles/obj.clangDependencyScanning.dir/InProcessModuleCache.cpp.o
[3192/4057] Building CXX object tools/clang/lib/Analysis/FlowSensitive/Models/CMakeFiles/obj.clangAnalysisFlowSensitiveModels.dir/UncheckedOptionalAccessModel.cpp.o
[3193/4057] Building CXX object tools/clang/lib/Frontend/CMakeFiles/obj.clangFrontend.dir/ModuleDependencyCollector.cpp.o
[3194/4057] Building CXX object tools/clang/lib/CodeGen/CMakeFiles/obj.clangCodeGen.dir/CodeGenModule.cpp.o
[3195/4057] Building CXX object tools/clang/lib/Tooling/Refactoring/CMakeFiles/obj.clangToolingRefactoring.dir/Extract/Extract.cpp.o
[3196/4057] Building CXX object tools/clang/lib/Tooling/Syntax/CMakeFiles/obj.clangToolingSyntax.dir/Mutations.cpp.o
[3197/4057] Building CXX object tools/clang/lib/Frontend/CMakeFiles/obj.clangFrontend.dir/TestModuleFileExtension.cpp.o
[3198/4057] Building CXX object tools/clang/lib/Tooling/DependencyScanning/CMakeFiles/obj.clangDependencyScanning.dir/DependencyScanningFilesystem.cpp.o
[3199/4057] Building CXX object tools/clang/lib/Frontend/CMakeFiles/obj.clangFrontend.dir/InitPreprocessor.cpp.o
[3200/4057] Building CXX object tools/clang/lib/Tooling/Syntax/CMakeFiles/obj.clangToolingSyntax.dir/Synthesis.cpp.o
[3201/4057] Building CXX object tools/clang/lib/Driver/CMakeFiles/obj.clangDriver.dir/ToolChains/Clang.cpp.o
[3202/4057] Building CXX object tools/clang/lib/Tooling/CMakeFiles/obj.clangTooling.dir/ExpandResponseFilesCompilationDatabase.cpp.o
[3203/4057] Building CXX object tools/clang/lib/Tooling/CMakeFiles/obj.clangTooling.dir/LocateToolCompilationDatabase.cpp.o
[3204/4057] Building CXX object tools/clang/lib/Tooling/CMakeFiles/obj.clangTooling.dir/Execution.cpp.o
[3205/4057] Building CXX object tools/clang/lib/Frontend/CMakeFiles/obj.clangFrontend.dir/ChainedIncludesSource.cpp.o
[3206/4057] Building CXX object tools/clang/lib/Tooling/CMakeFiles/obj.clangTooling.dir/GuessTargetAndModeCompilationDatabase.cpp.o
[3207/4057] Building CXX object tools/clang/lib/Tooling/CMakeFiles/obj.clangTooling.dir/JSONCompilationDatabase.cpp.o
[3208/4057] Building CXX object tools/clang/lib/Tooling/CMakeFiles/obj.clangTooling.dir/Refactoring.cpp.o
[3209/4057] Building CXX object tools/clang/lib/Frontend/CMakeFiles/obj.clangFrontend.dir/PrecompiledPreamble.cpp.o
[3210/4057] Building CXX object tools/clang/lib/Tooling/CMakeFiles/obj.clangTooling.dir/AllTUsExecution.cpp.o
[3211/4057] Building CXX object tools/clang/lib/Serialization/CMakeFiles/obj.clangSerialization.dir/ASTWriterStmt.cpp.o
[3212/4057] Building CXX object tools/clang/lib/Tooling/CMakeFiles/obj.clangTooling.dir/CommonOptionsParser.cpp.o
[3213/4057] Building CXX object tools/clang/lib/Tooling/CMakeFiles/obj.clangTooling.dir/CompilationDatabase.cpp.o
[3214/4057] Building CXX object tools/clang/lib/Tooling/Syntax/CMakeFiles/obj.clangToolingSyntax.dir/Tokens.cpp.o
[3215/4057] Building CXX object tools/clang/lib/FrontendTool/CMakeFiles/obj.clangFrontendTool.dir/ExecuteCompilerInvocation.cpp.o

```

</details>

https://github.com/llvm/llvm-project/pull/129751