Index: include/clang/CrossTU/CrossTranslationUnit.h =================================================================== --- include/clang/CrossTU/CrossTranslationUnit.h +++ include/clang/CrossTU/CrossTranslationUnit.h @@ -45,7 +45,8 @@ failed_to_generate_usr, triple_mismatch, lang_mismatch, - lang_dialect_mismatch + lang_dialect_mismatch, + load_threshold_reached }; class IndexError : public llvm::ErrorInfo { @@ -134,7 +135,8 @@ /// A definition with the same declaration will be looked up in the /// index file which should be in the \p CrossTUDir directory, called /// \p IndexName. In case the declaration is found in the index the - /// corresponding AST file will be loaded. + /// corresponding AST file will be loaded. If the number of TUs imported + /// reaches \p CTULoadTreshold, no loading is performed. /// /// \return Returns a pointer to the ASTUnit that contains the definition of /// the looked up name or an Error. @@ -182,6 +184,10 @@ CompilerInstance &CI; ASTContext &Context; std::unique_ptr LookupTable; + /// \p CTULoadTreshold should serve as an upper limit to the number of TUs + /// imported in order to reduce the memory footprint of CTU analysis. + const unsigned CTULoadThreshold; + unsigned NumASTLoaded{0u}; }; } // namespace cross_tu Index: include/clang/StaticAnalyzer/Core/AnalyzerOptions.def =================================================================== --- include/clang/StaticAnalyzer/Core/AnalyzerOptions.def +++ include/clang/StaticAnalyzer/Core/AnalyzerOptions.def @@ -287,6 +287,14 @@ "the analyzer's progress related to ctu.", false) +ANALYZER_OPTION(unsigned, CTUImportThreshold, "ctu-import-threshold", + "The maximal amount of translation units that is considered " + "for import when inlining functions during CTU analysis. " + "Lowering this threshold can alleviate the memory burder of " + "analysis with many interdependent definitions located in " + "various translation units.", + 100u) + //===----------------------------------------------------------------------===// // Unsinged analyzer options. //===----------------------------------------------------------------------===// Index: lib/CrossTU/CrossTranslationUnit.cpp =================================================================== --- lib/CrossTU/CrossTranslationUnit.cpp +++ lib/CrossTU/CrossTranslationUnit.cpp @@ -43,6 +43,8 @@ STATISTIC(NumTripleMismatch, "The # of triple mismatches"); STATISTIC(NumLangMismatch, "The # of language mismatches"); STATISTIC(NumLangDialectMismatch, "The # of language dialect mismatches"); +STATISTIC(NumASTLoadThresholdReached, + "The # of ASTs not loaded because of threshold"); // Same as Triple's equality operator, but we check a field only if that is // known in both instances. @@ -102,6 +104,8 @@ return "Language mismatch"; case index_error_code::lang_dialect_mismatch: return "Language dialect mismatch"; + case index_error_code::load_threshold_reached: + return "Load threshold reached"; } llvm_unreachable("Unrecognized index_error_code."); } @@ -180,7 +184,8 @@ } CrossTranslationUnitContext::CrossTranslationUnitContext(CompilerInstance &CI) - : CI(CI), Context(CI.getASTContext()) {} + : CI(CI), Context(CI.getASTContext()), + CTULoadThreshold(CI.getAnalyzerOpts()->CTUImportThreshold) {} CrossTranslationUnitContext::~CrossTranslationUnitContext() {} @@ -228,8 +233,8 @@ if (LookupName.empty()) return llvm::make_error( index_error_code::failed_to_generate_usr); - llvm::Expected ASTUnitOrError = - loadExternalAST(LookupName, CrossTUDir, IndexName, DisplayCTUProgress); + llvm::Expected ASTUnitOrError = loadExternalAST( + LookupName, CrossTUDir, IndexName, DisplayCTUProgress); if (!ASTUnitOrError) return ASTUnitOrError.takeError(); ASTUnit *Unit = *ASTUnitOrError; @@ -338,6 +343,13 @@ // a lookup name from a single translation unit. If multiple // translation units contains decls with the same lookup name an // error will be returned. + + if (NumASTLoaded >= CTULoadThreshold) { + ++NumASTLoadThresholdReached; + return llvm::make_error( + index_error_code::load_threshold_reached); + } + ASTUnit *Unit = nullptr; auto NameUnitCacheEntry = NameASTUnitMap.find(LookupName); if (NameUnitCacheEntry == NameASTUnitMap.end()) { @@ -375,6 +387,7 @@ ASTUnit::LoadEverything, Diags, CI.getFileSystemOpts())); Unit = LoadedUnit.get(); FileASTUnitMap[ASTFileName] = std::move(LoadedUnit); + ++NumASTLoaded; if (DisplayCTUProgress) { llvm::errs() << "CTU loaded AST file: " << ASTFileName << "\n"; Index: test/Analysis/analyzer-config.c =================================================================== --- test/Analysis/analyzer-config.c +++ test/Analysis/analyzer-config.c @@ -20,6 +20,7 @@ // CHECK-NEXT: cfg-temporary-dtors = true // CHECK-NEXT: crosscheck-with-z3 = false // CHECK-NEXT: ctu-dir = "" +// CHECK-NEXT: ctu-import-threshold = 100 // CHECK-NEXT: ctu-index-name = externalDefMap.txt // CHECK-NEXT: display-ctu-progress = false // CHECK-NEXT: eagerly-assume = true @@ -52,4 +53,4 @@ // CHECK-NEXT: unroll-loops = false // CHECK-NEXT: widen-loops = false // CHECK-NEXT: [stats] -// CHECK-NEXT: num-entries = 49 +// CHECK-NEXT: num-entries = 50 Index: test/Analysis/ctu-import-threshold.c =================================================================== --- /dev/null +++ test/Analysis/ctu-import-threshold.c @@ -0,0 +1,5 @@ +// Ensure analyzer option 'ctu-import-threshold' is a recognized option. +// +// RUN: %clang_cc1 -analyze -analyzer-config ctu-import-threshold=30 -verify %s +// +// expected-no-diagnostics Index: unittests/CrossTU/CrossTranslationUnitTest.cpp =================================================================== --- unittests/CrossTU/CrossTranslationUnitTest.cpp +++ unittests/CrossTU/CrossTranslationUnitTest.cpp @@ -7,6 +7,7 @@ //===----------------------------------------------------------------------===// #include "clang/CrossTU/CrossTranslationUnit.h" +#include "clang/Frontend/CompilerInstance.h" #include "clang/AST/ASTConsumer.h" #include "clang/Frontend/FrontendAction.h" #include "clang/Tooling/Tooling.h" @@ -70,12 +71,14 @@ EXPECT_TRUE(llvm::sys::fs::exists(ASTFileName)); // Load the definition from the AST file. - llvm::Expected NewFDorError = - CTU.getCrossTUDefinition(FD, "", IndexFileName); - EXPECT_TRUE((bool)NewFDorError); - const FunctionDecl *NewFD = *NewFDorError; + llvm::Expected NewFDorError = handleExpected( + CTU.getCrossTUDefinition(FD, "", IndexFileName, false), + []() { return nullptr; }, [](IndexError &) {}); - *Success = NewFD && NewFD->hasBody() && !OrigFDHasBody; + if (NewFDorError) { + const FunctionDecl *NewFD = *NewFDorError; + *Success = NewFD && NewFD->hasBody() && !OrigFDHasBody; + } } private: @@ -85,26 +88,37 @@ class CTUAction : public clang::ASTFrontendAction { public: - CTUAction(bool *Success) : Success(Success) {} + CTUAction(bool *Success, unsigned OverrideLimit) + : Success(Success), OverrideLimit(OverrideLimit) {} protected: std::unique_ptr CreateASTConsumer(clang::CompilerInstance &CI, StringRef) override { + CI.getAnalyzerOpts()->CTUImportThreshold = OverrideLimit; return llvm::make_unique(CI, Success); } private: bool *Success; + const unsigned OverrideLimit; }; } // end namespace TEST(CrossTranslationUnit, CanLoadFunctionDefinition) { bool Success = false; - EXPECT_TRUE(tooling::runToolOnCode(new CTUAction(&Success), "int f(int);")); + EXPECT_TRUE( + tooling::runToolOnCode(new CTUAction(&Success, 1u), "int f(int);")); EXPECT_TRUE(Success); } +TEST(CrossTranslationUnit, RespectsLoadThreshold) { + bool Success = false; + EXPECT_TRUE( + tooling::runToolOnCode(new CTUAction(&Success, 0u), "int f(int);")); + EXPECT_FALSE(Success); +} + TEST(CrossTranslationUnit, IndexFormatCanBeParsed) { llvm::StringMap Index; Index["a"] = "/b/f1";