llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: Ryosuke Niwa (rniwa) <details> <summary>Changes</summary> This PR fixes a bug that when a template specialization is declared with a forward declaration of a template, the checker fails to find its definition in the same translation unit and erroneously emit an unsafe forward declaration warning. --- Full diff: https://github.com/llvm/llvm-project/pull/134545.diff 2 Files Affected: - (modified) clang/lib/StaticAnalyzer/Checkers/WebKit/ForwardDeclChecker.cpp (+12-2) - (modified) clang/test/Analysis/Checkers/WebKit/forward-decl-checker.mm (+17) ``````````diff diff --git a/clang/lib/StaticAnalyzer/Checkers/WebKit/ForwardDeclChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/WebKit/ForwardDeclChecker.cpp index 2c63224df129a..4f63e5ed866ed 100644 --- a/clang/lib/StaticAnalyzer/Checkers/WebKit/ForwardDeclChecker.cpp +++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/ForwardDeclChecker.cpp @@ -125,8 +125,18 @@ class ForwardDeclChecker : public Checker<check::ASTDecl<TranslationUnitDecl>> { if (!R) // Forward declaration of a Objective-C interface is safe. return false; auto Name = R->getName(); - return !R->hasDefinition() && !RTC.isUnretained(QT) && - !SystemTypes.contains(CanonicalType) && + if (R->hasDefinition()) + return false; + // Find a definition amongst template declarations. + if (auto *Specialization = dyn_cast<ClassTemplateSpecializationDecl>(R)) { + if (auto* S = Specialization->getSpecializedTemplate()) { + for (S = S->getMostRecentDecl(); S; S = S->getPreviousDecl()) { + if (S->isThisDeclarationADefinition()) + return false; + } + } + } + return !RTC.isUnretained(QT) && !SystemTypes.contains(CanonicalType) && !SystemTypes.contains(PointeeType) && !Name.starts_with("Opaque") && Name != "_NSZone"; } diff --git a/clang/test/Analysis/Checkers/WebKit/forward-decl-checker.mm b/clang/test/Analysis/Checkers/WebKit/forward-decl-checker.mm index 64100d60c4867..084b47322d7f9 100644 --- a/clang/test/Analysis/Checkers/WebKit/forward-decl-checker.mm +++ b/clang/test/Analysis/Checkers/WebKit/forward-decl-checker.mm @@ -138,3 +138,20 @@ - (void)doMoreWork:(ObjCObj *)obj { } @end + +namespace template_forward_declare { + +template<typename> class HashSet; + +template<typename T> +using SingleThreadHashSet = HashSet<T>; + +template<typename> class HashSet { }; + +struct Font { }; + +struct ComplexTextController { + SingleThreadHashSet<const Font>* fallbackFonts { nullptr }; +}; + +} `````````` </details> https://github.com/llvm/llvm-project/pull/134545 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
