Author: martinboehme Date: 2024-06-26T15:01:57+02:00 New Revision: dfe80a73223edff5c53f8be7925d302883cb40bc
URL: https://github.com/llvm/llvm-project/commit/dfe80a73223edff5c53f8be7925d302883cb40bc DIFF: https://github.com/llvm/llvm-project/commit/dfe80a73223edff5c53f8be7925d302883cb40bc.diff LOG: [clang][dataflow] Teach `AnalysisASTVisitor` that `typeid()` can be evaluated. (#96731) We were previously treating the operand of `typeid()` as being definitely unevaluated, but it can be evaluated if it is a glvalue of polymorphic type. This patch includes a test that fails without the fix. Added: Modified: clang/include/clang/Analysis/FlowSensitive/ASTOps.h clang/unittests/Analysis/FlowSensitive/TransferTest.cpp Removed: ################################################################################ diff --git a/clang/include/clang/Analysis/FlowSensitive/ASTOps.h b/clang/include/clang/Analysis/FlowSensitive/ASTOps.h index 925b99af9141a..f9c923a36ad22 100644 --- a/clang/include/clang/Analysis/FlowSensitive/ASTOps.h +++ b/clang/include/clang/Analysis/FlowSensitive/ASTOps.h @@ -113,7 +113,11 @@ class AnalysisASTVisitor : public RecursiveASTVisitor<Derived> { // nevertheless it appears in the Clang CFG, so we don't exclude it here. bool TraverseDecltypeTypeLoc(DecltypeTypeLoc) { return true; } bool TraverseTypeOfExprTypeLoc(TypeOfExprTypeLoc) { return true; } - bool TraverseCXXTypeidExpr(CXXTypeidExpr *) { return true; } + bool TraverseCXXTypeidExpr(CXXTypeidExpr *TIE) { + if (TIE->isPotentiallyEvaluated()) + return RecursiveASTVisitor<Derived>::TraverseCXXTypeidExpr(TIE); + return true; + } bool TraverseUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr *) { return true; } diff --git a/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp b/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp index cfbc64c77b0cc..2ce83399c5453 100644 --- a/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp +++ b/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp @@ -1637,6 +1637,49 @@ TEST(TransferTest, StructModeledFieldsWithAccessor) { }); } +TEST(TransferTest, StructModeledFieldsInTypeid) { + // Test that we model fields mentioned inside a `typeid()` expression only if + // that expression is potentially evaluated -- i.e. if the expression inside + // `typeid()` is a glvalue of polymorphic type (see + // `CXXTypeidExpr::isPotentiallyEvaluated()` and [expr.typeid]p3). + std::string Code = R"( + // Definitions needed for `typeid`. + namespace std { + class type_info {}; + class bad_typeid {}; + } // namespace std + + struct NonPolymorphic {}; + + struct Polymorphic { + virtual ~Polymorphic() = default; + }; + + struct S { + NonPolymorphic *NonPoly; + Polymorphic *Poly; + }; + + void target(S &s) { + typeid(*s.NonPoly); + typeid(*s.Poly); + // [[p]] + } + )"; + runDataflow( + Code, + [](const llvm::StringMap<DataflowAnalysisState<NoopLattice>> &Results, + ASTContext &ASTCtx) { + const Environment &Env = getEnvironmentAtAnnotation(Results, "p"); + auto &SLoc = getLocForDecl<RecordStorageLocation>(ASTCtx, Env, "s"); + std::vector<const ValueDecl *> Fields; + for (auto [Field, _] : SLoc.children()) + Fields.push_back(Field); + EXPECT_THAT(Fields, + UnorderedElementsAre(findValueDecl(ASTCtx, "Poly"))); + }); +} + TEST(TransferTest, StructModeledFieldsWithComplicatedInheritance) { std::string Code = R"( struct Base1 { _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
