llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: Haojian Wu (hokein) <details> <summary>Changes</summary> In the crash example, when performing typo correction for a qualified name lookup (`::a`), clang suggests a template template parameter from an outer scope. However, template template parameters can not be qualified by any scope. Attempting to combine the qualifier with the suggested template template parameter resulted in an assertion failure in `ASTContext::getQualifiedTemplateName`: This patch is to update the typo correction filter to reject `TemplateTemplateParmDecl` candidates when a qualifier is present . This prevents the invalid suggestion from being generated and avoids the assertion violation. Fixes #<!-- -->183983 --- Full diff: https://github.com/llvm/llvm-project/pull/188239.diff 2 Files Affected: - (modified) clang/lib/Sema/SemaTemplate.cpp (+21-1) - (added) clang/test/SemaTemplate/gh183983.cpp (+10) ``````````diff diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp index 5d23660585ea5b..1e591a0f3c4e97 100644 --- a/clang/lib/Sema/SemaTemplate.cpp +++ b/clang/lib/Sema/SemaTemplate.cpp @@ -520,7 +520,27 @@ bool Sema::LookupTemplateName(LookupResult &Found, Scope *S, CXXScopeSpec &SS, DeclarationName Name = Found.getLookupName(); Found.clear(); // Simple filter callback that, for keywords, only accepts the C++ *_cast - DefaultFilterCCC FilterCCC{}; + struct TemplateQualifierFilter final : CorrectionCandidateCallback { + const CXXScopeSpec &SS; + TemplateQualifierFilter(const CXXScopeSpec &SS) : SS(SS) {} + bool ValidateCandidate(const TypoCorrection &Candidate) override { + if (SS.isNotEmpty()) { // Qualified lookup + if (NamedDecl *ND = Candidate.getFoundDecl()) { + // A template template parameter is a name in the current template + // parameter list and cannot be validly qualified by any scope. + // Therefore, we should never suggest it as a typo correction for a + // qualified name. + if (isa<TemplateTemplateParmDecl>(ND)) + return false; + } + } + return CorrectionCandidateCallback::ValidateCandidate(Candidate); + } + std::unique_ptr<CorrectionCandidateCallback> clone() override { + return std::make_unique<TemplateQualifierFilter>(*this); + } + }; + TemplateQualifierFilter FilterCCC{SS}; FilterCCC.WantTypeSpecifiers = false; FilterCCC.WantExpressionKeywords = false; FilterCCC.WantRemainingKeywords = false; diff --git a/clang/test/SemaTemplate/gh183983.cpp b/clang/test/SemaTemplate/gh183983.cpp new file mode 100644 index 00000000000000..368176290dba1e --- /dev/null +++ b/clang/test/SemaTemplate/gh183983.cpp @@ -0,0 +1,10 @@ +// RUN: %clang_cc1 -fsyntax-only -verify %s + +// expected-error@10 {{template template parameter requires 'class' or 'typename' after the parameter list}} +// expected-error@10 {{template template parameter must have its own template parameters}} +// expected-error@10 {{no template named 'a' in the global namespace}} +// expected-note@10 {{to match this '<'}} +// expected-error@10 {{expected expression}} +// expected-error@10 {{expected '>'}} +// expected-error@10 {{expected unqualified-id}} +template <template <> a>::a < `````````` </details> https://github.com/llvm/llvm-project/pull/188239 _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
