llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang-static-analyzer-1 Author: None (NagyDonat) <details> <summary>Changes</summary> This reapplies 80ab8234ac309418637488b97e0a62d8377b2ecf again, after fixing a name collision warning in the unit tests (see the revert commit 13ccaf9b9d4400bb128b35ff4ac733e4afc3ad1c for details). --- Full diff: https://github.com/llvm/llvm-project/pull/85791.diff 5 Files Affected: - (modified) clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h (+2-6) - (modified) clang/lib/StaticAnalyzer/Core/CheckerContext.cpp (+5-3) - (modified) clang/unittests/StaticAnalyzer/CMakeLists.txt (+1) - (added) clang/unittests/StaticAnalyzer/IsCLibraryFunctionTest.cpp (+82) - (modified) llvm/utils/gn/secondary/clang/unittests/StaticAnalyzer/BUILD.gn (+1) ``````````diff diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h index 3432d2648633c2..b4e1636130ca7c 100644 --- a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h +++ b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h @@ -41,12 +41,8 @@ class CallDescription { /// - We also accept calls where the number of arguments or parameters is /// greater than the specified value. /// For the exact heuristics, see CheckerContext::isCLibraryFunction(). - /// Note that functions whose declaration context is not a TU (e.g. - /// methods, functions in namespaces) are not accepted as C library - /// functions. - /// FIXME: If I understand it correctly, this discards calls where C++ code - /// refers a C library function through the namespace `std::` via headers - /// like <cstdlib>. + /// (This mode only matches functions that are declared either directly + /// within a TU or in the namespace `std`.) CLibrary, /// Matches "simple" functions that are not methods. (Static methods are diff --git a/clang/lib/StaticAnalyzer/Core/CheckerContext.cpp b/clang/lib/StaticAnalyzer/Core/CheckerContext.cpp index d6d4cec9dd3d4d..1a9bff529e9bb1 100644 --- a/clang/lib/StaticAnalyzer/Core/CheckerContext.cpp +++ b/clang/lib/StaticAnalyzer/Core/CheckerContext.cpp @@ -87,9 +87,11 @@ bool CheckerContext::isCLibraryFunction(const FunctionDecl *FD, if (!II) return false; - // Look through 'extern "C"' and anything similar invented in the future. - // If this function is not in TU directly, it is not a C library function. - if (!FD->getDeclContext()->getRedeclContext()->isTranslationUnit()) + // C library functions are either declared directly within a TU (the common + // case) or they are accessed through the namespace `std` (when they are used + // in C++ via headers like <cstdlib>). + const DeclContext *DC = FD->getDeclContext()->getRedeclContext(); + if (!(DC->isTranslationUnit() || DC->isStdNamespace())) return false; // If this function is not externally visible, it is not a C library function. diff --git a/clang/unittests/StaticAnalyzer/CMakeLists.txt b/clang/unittests/StaticAnalyzer/CMakeLists.txt index 775f0f8486b8f9..db56e77331b821 100644 --- a/clang/unittests/StaticAnalyzer/CMakeLists.txt +++ b/clang/unittests/StaticAnalyzer/CMakeLists.txt @@ -11,6 +11,7 @@ add_clang_unittest(StaticAnalysisTests CallEventTest.cpp ConflictingEvalCallsTest.cpp FalsePositiveRefutationBRVisitorTest.cpp + IsCLibraryFunctionTest.cpp NoStateChangeFuncVisitorTest.cpp ParamRegionTest.cpp RangeSetTest.cpp diff --git a/clang/unittests/StaticAnalyzer/IsCLibraryFunctionTest.cpp b/clang/unittests/StaticAnalyzer/IsCLibraryFunctionTest.cpp new file mode 100644 index 00000000000000..f26acf07e23ac0 --- /dev/null +++ b/clang/unittests/StaticAnalyzer/IsCLibraryFunctionTest.cpp @@ -0,0 +1,82 @@ +#include "clang/ASTMatchers/ASTMatchFinder.h" +#include "clang/ASTMatchers/ASTMatchers.h" +#include "clang/Analysis/AnalysisDeclContext.h" +#include "clang/Frontend/ASTUnit.h" +#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h" +#include "clang/Tooling/Tooling.h" +#include "gtest/gtest.h" + +#include <memory> + +using namespace clang; +using namespace ento; +using namespace ast_matchers; + +class IsCLibraryFunctionTest : public testing::Test { + std::unique_ptr<ASTUnit> ASTUnitP; + const FunctionDecl *Result = nullptr; +public: + const FunctionDecl *getFunctionDecl() const { return Result; } + + testing::AssertionResult buildAST(StringRef Code) { + ASTUnitP = tooling::buildASTFromCode(Code); + if (!ASTUnitP) + return testing::AssertionFailure() << "AST construction failed"; + + ASTContext &Context = ASTUnitP->getASTContext(); + if (Context.getDiagnostics().hasErrorOccurred()) + return testing::AssertionFailure() << "Compilation error"; + + auto Matches = ast_matchers::match(functionDecl().bind("fn"), Context); + if (Matches.empty()) + return testing::AssertionFailure() << "No function declaration found"; + + if (Matches.size() > 1) + return testing::AssertionFailure() + << "Multiple function declarations found"; + + Result = Matches[0].getNodeAs<FunctionDecl>("fn"); + return testing::AssertionSuccess(); + } +}; + +TEST_F(IsCLibraryFunctionTest, AcceptsGlobal) { + ASSERT_TRUE(buildAST(R"cpp(void fun();)cpp")); + EXPECT_TRUE(CheckerContext::isCLibraryFunction(getFunctionDecl())); +} + +TEST_F(IsCLibraryFunctionTest, AcceptsExternCGlobal) { + ASSERT_TRUE(buildAST(R"cpp(extern "C" { void fun(); })cpp")); + EXPECT_TRUE(CheckerContext::isCLibraryFunction(getFunctionDecl())); +} + +TEST_F(IsCLibraryFunctionTest, RejectsNoInlineNoExternalLinkage) { + // Functions that are neither inlined nor externally visible cannot be C library functions. + ASSERT_TRUE(buildAST(R"cpp(static void fun();)cpp")); + EXPECT_FALSE(CheckerContext::isCLibraryFunction(getFunctionDecl())); +} + +TEST_F(IsCLibraryFunctionTest, RejectsAnonymousNamespace) { + ASSERT_TRUE(buildAST(R"cpp(namespace { void fun(); })cpp")); + EXPECT_FALSE(CheckerContext::isCLibraryFunction(getFunctionDecl())); +} + +TEST_F(IsCLibraryFunctionTest, AcceptsStdNamespace) { + ASSERT_TRUE(buildAST(R"cpp(namespace std { void fun(); })cpp")); + EXPECT_TRUE(CheckerContext::isCLibraryFunction(getFunctionDecl())); +} + +TEST_F(IsCLibraryFunctionTest, RejectsOtherNamespaces) { + ASSERT_TRUE(buildAST(R"cpp(namespace stdx { void fun(); })cpp")); + EXPECT_FALSE(CheckerContext::isCLibraryFunction(getFunctionDecl())); +} + +TEST_F(IsCLibraryFunctionTest, RejectsClassStatic) { + ASSERT_TRUE(buildAST(R"cpp(class A { static void fun(); };)cpp")); + EXPECT_FALSE(CheckerContext::isCLibraryFunction(getFunctionDecl())); +} + +TEST_F(IsCLibraryFunctionTest, RejectsClassMember) { + ASSERT_TRUE(buildAST(R"cpp(class A { void fun(); };)cpp")); + EXPECT_FALSE(CheckerContext::isCLibraryFunction(getFunctionDecl())); +} diff --git a/llvm/utils/gn/secondary/clang/unittests/StaticAnalyzer/BUILD.gn b/llvm/utils/gn/secondary/clang/unittests/StaticAnalyzer/BUILD.gn index 01c2b6ced3366f..9c240cff181634 100644 --- a/llvm/utils/gn/secondary/clang/unittests/StaticAnalyzer/BUILD.gn +++ b/llvm/utils/gn/secondary/clang/unittests/StaticAnalyzer/BUILD.gn @@ -19,6 +19,7 @@ unittest("StaticAnalysisTests") { "CallEventTest.cpp", "ConflictingEvalCallsTest.cpp", "FalsePositiveRefutationBRVisitorTest.cpp", + "IsCLibraryFunctionTest.cpp", "NoStateChangeFuncVisitorTest.cpp", "ParamRegionTest.cpp", "RangeSetTest.cpp", `````````` </details> https://github.com/llvm/llvm-project/pull/85791 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
