Author: Daniel M. Katz Date: 2025-11-23T11:11:58+08:00 New Revision: 525e68e9e9a44e88eb88ef2d6f058a482972c989
URL: https://github.com/llvm/llvm-project/commit/525e68e9e9a44e88eb88ef2d6f058a482972c989 DIFF: https://github.com/llvm/llvm-project/commit/525e68e9e9a44e88eb88ef2d6f058a482972c989.diff LOG: Don't mark lambda non-dependent if nested in a generic lambda. (#149121) Fixes #118187 Fixes #156579 An instantiated `LambdaExpr` can currently be marked as `LDK_NeverDependent` if it's nested within a generic lambda. If that `LambdaExpr` in fact depends on template parameters introduced by the enclosing generic lambda, then its dependence will be misreported as "never dependent" and spurious diagnostics can result. The fix here proposed is a bit ugly, but the condition that it's being bolted onto already seems like a bit of a hack, so this seems no worse for wear. Note that #89702 surfaced this change because it caused the inner lambda expression to (correctly) be considered in a constant-evaluated context. The affected check for whether to mark the inner lambda as `LDK_NeverDependent` therefore started to apply, whereas it didn't before. **Tested**: `check-clang` and `check-cxx`. Added: Modified: clang/docs/ReleaseNotes.rst clang/lib/Sema/TreeTransform.h clang/test/SemaCXX/cxx2a-consteval.cpp Removed: ################################################################################ diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 63930f43c25e3..8161ccdffca82 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -557,6 +557,7 @@ Bug Fixes to C++ Support - Diagnose unresolved overload sets in non-dependent compound requirements. (#GH51246) (#GH97753) - Fix a crash when extracting unavailable member type from alias in template deduction. (#GH165560) - Fix incorrect diagnostics for lambdas with init-captures inside braced initializers. (#GH163498) +- Fixed spurious diagnoses of certain nested lambda expressions. (#GH149121) (#GH156579) Bug Fixes to AST Handling ^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h index c2491489f40d2..0e8b674a006d0 100644 --- a/clang/lib/Sema/TreeTransform.h +++ b/clang/lib/Sema/TreeTransform.h @@ -15628,6 +15628,8 @@ TreeTransform<Derived>::TransformLambdaExpr(LambdaExpr *E) { DC = DC->getParent(); if ((getSema().isUnevaluatedContext() || getSema().isConstantEvaluatedContext()) && + !(dyn_cast_or_null<CXXRecordDecl>(DC->getParent()) && + cast<CXXRecordDecl>(DC->getParent())->isGenericLambda()) && (DC->isFileContext() || !DC->getParent()->isDependentContext())) DependencyKind = CXXRecordDecl::LDK_NeverDependent; diff --git a/clang/test/SemaCXX/cxx2a-consteval.cpp b/clang/test/SemaCXX/cxx2a-consteval.cpp index 1474c48cda3c1..92bfa40caec4e 100644 --- a/clang/test/SemaCXX/cxx2a-consteval.cpp +++ b/clang/test/SemaCXX/cxx2a-consteval.cpp @@ -1319,6 +1319,27 @@ namespace GH139160{ B result = (B){10, get_value(make_struct())}; // expected-error {{initializer element is not a compile-time constant}} // expected-error@-1 {{call to consteval function 'GH139160::get_value' is not a constant expression}} // expected-note@-2 {{non-constexpr function 'make_struct' cannot be used in a constant expression}} -}; +} // namespace GH139160 + +namespace GH118187 { + +template <typename T> int t() { + return []<typename U>() consteval { + return [](U v) { return v; }(123); + }.template operator()<int>(); +} +int v = t<int>(); +} // namespace GH118187 +namespace GH156579 { +template <class> +auto f{[] (auto...) { + if constexpr ([] (auto) { return true; }(0)) + return 0; +}}; + +void g() { + f<int>(); +} +} // namespace GH156579 _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
