llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang-modules Author: Jan Svoboda (jansvoboda11) <details> <summary>Changes</summary> When writing out a PCM, we compute the set of module maps that did affect the compilation and we strip the rest to make the output independent of them. The most common way to read a module map that is not affecting is with implicit module map search. The other option is to pass a bunch of unnecessary `-fmodule-map-file=<path>` arguments on the command-line, in which case the client should probably not give those to Clang anyway. This makes serialization of explicit modules faster, mostly due to reduced file system traffic. --- Full diff: https://github.com/llvm/llvm-project/pull/87849.diff 1 Files Affected: - (modified) clang/lib/Serialization/ASTWriter.cpp (+17-4) ``````````diff diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp index ba6a8a5e16e4e7..e1e22017595518 100644 --- a/clang/lib/Serialization/ASTWriter.cpp +++ b/clang/lib/Serialization/ASTWriter.cpp @@ -161,8 +161,13 @@ static TypeCode getTypeCodeForTypeClass(Type::TypeClass id) { namespace { -std::set<const FileEntry *> GetAffectingModuleMaps(const Preprocessor &PP, - Module *RootModule) { +std::optional<std::set<const FileEntry *>> +GetAffectingModuleMaps(const Preprocessor &PP, Module *RootModule) { + // Without implicit module map search, there's no good reason to know about + // any module maps that are not affecting. + if (!PP.getHeaderSearchInfo().getHeaderSearchOpts().ImplicitModuleMaps) + return std::nullopt; + SmallVector<const Module *> ModulesToProcess{RootModule}; const HeaderSearch &HS = PP.getHeaderSearchInfo(); @@ -4733,8 +4738,16 @@ void ASTWriter::computeNonAffectingInputFiles() { if (!Cache->OrigEntry) continue; - if (!isModuleMap(File.getFileCharacteristic()) || - llvm::is_contained(AffectingModuleMaps, *Cache->OrigEntry)) + // Don't prune anything other than module maps. + if (!isModuleMap(File.getFileCharacteristic())) + continue; + + // Don't prune module maps if all are guaranteed to be affecting. + if (!AffectingModuleMaps) + continue; + + // Don't prune module maps that are affecting. + if (llvm::is_contained(*AffectingModuleMaps, *Cache->OrigEntry)) continue; IsSLocAffecting[I] = false; `````````` </details> https://github.com/llvm/llvm-project/pull/87849 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
