[clang-tools-extra] [clangd] [Modules] Support Reusable Modules Builder (PR #106683)
kadir çetinkaya via cfe-commits
cfe-commits at lists.llvm.org
Mon Nov 4 05:18:07 PST 2024
================
@@ -316,36 +287,169 @@ llvm::Error buildModuleFile(llvm::StringRef ModuleName,
if (Clang->getDiagnostics().hasErrorOccurred())
return llvm::createStringError("Compilation failed");
- BuiltModuleFiles.addModuleFile(ModuleName, Inputs.CompileCommand.Output);
- return llvm::Error::success();
+ return ModuleFile{ModuleName, Inputs.CompileCommand.Output};
+}
+
+bool ReusablePrerequisiteModules::canReuse(
+ const CompilerInvocation &CI,
+ llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS) const {
+ if (RequiredModules.empty())
+ return true;
+
+ SmallVector<StringRef> BMIPaths;
+ for (auto &MF : RequiredModules)
+ BMIPaths.push_back(MF->ModuleFilePath);
+ return IsModuleFilesUpToDate(BMIPaths, *this, VFS);
}
} // namespace
+class ModulesBuilder::ModuleFileCache {
+public:
+ ModuleFileCache(const GlobalCompilationDatabase &CDB) : CDB(CDB) {}
+
+ llvm::Error
+ getOrBuildModuleFile(StringRef ModuleName, const ThreadsafeFS &TFS,
+ ProjectModules &MDB,
+ ReusablePrerequisiteModules &RequiredModules);
+ const GlobalCompilationDatabase &getCDB() const { return CDB; }
+
+private:
+ std::shared_ptr<ModuleFile>
+ getValidModuleFile(StringRef ModuleName, ProjectModules &MDB,
+ const ThreadsafeFS &TFS,
+ PrerequisiteModules &BuiltModuleFiles);
+
+ /// This should only be called by getValidModuleFile. This is unlocked version
+ /// of getValidModuleFile. The function is extracted to avoid dead locks when
+ /// recursing.
+ std::shared_ptr<ModuleFile>
+ isValidModuleFileUnlocked(StringRef ModuleName, ProjectModules &MDB,
+ const ThreadsafeFS &TFS,
+ PrerequisiteModules &BuiltModuleFiles);
+
+ const GlobalCompilationDatabase &CDB;
+
+ llvm::StringMap<std::shared_ptr<ModuleFile>> ModuleFiles;
+ // Mutex to guard accesses to ModuleFiles.
+ std::mutex ModuleFilesMutex;
+};
+
+std::shared_ptr<ModuleFile>
+ModulesBuilder::ModuleFileCache::isValidModuleFileUnlocked(
+ StringRef ModuleName, ProjectModules &MDB, const ThreadsafeFS &TFS,
+ PrerequisiteModules &BuiltModuleFiles) {
+ auto Iter = ModuleFiles.find(ModuleName);
+ if (Iter != ModuleFiles.end()) {
+ if (!IsModuleFileUpToDate(Iter->second->ModuleFilePath, BuiltModuleFiles,
+ TFS.view(std::nullopt))) {
+ log("Found not-up-date module file {0} for module {1} in cache",
+ Iter->second->ModuleFilePath, ModuleName);
+ ModuleFiles.erase(Iter);
+ return nullptr;
+ }
+
+ if (llvm::any_of(
+ MDB.getRequiredModules(MDB.getSourceForModuleName(ModuleName)),
+ [&MDB, &TFS, &BuiltModuleFiles, this](auto &&RequiredModuleName) {
+ return !isValidModuleFileUnlocked(RequiredModuleName, MDB, TFS,
+ BuiltModuleFiles);
+ })) {
+ ModuleFiles.erase(Iter);
+ return nullptr;
+ }
+
+ return Iter->second;
+ }
+
+ log("Don't find {0} in cache", ModuleName);
+
+ return nullptr;
+}
+
+std::shared_ptr<ModuleFile> ModulesBuilder::ModuleFileCache::getValidModuleFile(
+ StringRef ModuleName, ProjectModules &MDB, const ThreadsafeFS &TFS,
+ PrerequisiteModules &BuiltModuleFiles) {
+ std::lock_guard<std::mutex> _(ModuleFilesMutex);
+
+ return isValidModuleFileUnlocked(ModuleName, MDB, TFS, BuiltModuleFiles);
+}
+
+llvm::Error ModulesBuilder::ModuleFileCache::getOrBuildModuleFile(
----------------
kadircet wrote:
i think we achieved the bit around cache just being a cache, but understanding of building a module is still split across two places. as `ModulesBuilderImpl` needs to know details of `buildModuleFile` (as it ensures to call this function only after all the dependent modules are traversed and build), and `buildModuleFile` knows the other bit around invoking a compilation and trusting it will only be called after all the dependencies are build.
Can we make sure all of this logic is contained in one place instead?
https://github.com/llvm/llvm-project/pull/106683
More information about the cfe-commits
mailing list