Author: Shafik Yaghmour Date: 2023-10-02T08:08:39-07:00 New Revision: f1fed124524151b73fbf153e946840730986ca6c
URL: https://github.com/llvm/llvm-project/commit/f1fed124524151b73fbf153e946840730986ca6c DIFF: https://github.com/llvm/llvm-project/commit/f1fed124524151b73fbf153e946840730986ca6c.diff LOG: [Clang] Fix crash when ill-formed code is treated as a deduction guide (#67373) In some cases where ill-formed code could be interpreted as a deduction guide we can crash because we reach an unreachable path. This fixes this issue by introducing a diagnostic instead. Fixes: https://github.com/llvm/llvm-project/issues/65522 Added: clang/test/SemaCXX/gh65522.cpp Modified: clang/docs/ReleaseNotes.rst clang/include/clang/Basic/DiagnosticSemaKinds.td clang/lib/Sema/SemaTemplateInstantiate.cpp Removed: ################################################################################ diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 5c70d5690a5d3f1..0c1023f63aae5d6 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -383,6 +383,10 @@ Bug Fixes to C++ Support - Fixed a bug causing destructors of constant-evaluated structured bindings initialized by array elements to be called in the wrong evaluation context. +- Fix crash where ill-formed code was being treated as a deduction guide and + we now produce a diagnostic. Fixes: + (`#65522 <https://github.com/llvm/llvm-project/issues/65522>`_) + Bug Fixes to AST Handling ^^^^^^^^^^^^^^^^^^^^^^^^^ - Fixed an import failure of recursive friend class template. diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td index 8c3815b5986c624..ac854a86a2fce23 100644 --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -5416,6 +5416,8 @@ def note_constraint_normalization_here : Note< def note_parameter_mapping_substitution_here : Note< "while substituting into concept arguments here; substitution failures not " "allowed in concept arguments">; +def note_building_deduction_guide_here : Note< + "while building implicit deduction guide first needed here">; def note_lambda_substitution_here : Note< "while substituting into a lambda expression here">; def note_instantiation_contexts_suppressed : Note< diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp index 8a74a5c0d6a236b..23de64080a070ca 100644 --- a/clang/lib/Sema/SemaTemplateInstantiate.cpp +++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp @@ -1075,7 +1075,9 @@ void Sema::PrintInstantiationStack() { << Active->InstantiationRange; break; case CodeSynthesisContext::BuildingDeductionGuides: - llvm_unreachable("unexpected deduction guide in instantiation stack"); + Diags.Report(Active->PointOfInstantiation, + diag::note_building_deduction_guide_here); + break; } } } diff --git a/clang/test/SemaCXX/gh65522.cpp b/clang/test/SemaCXX/gh65522.cpp new file mode 100644 index 000000000000000..2d6331b0372a31d --- /dev/null +++ b/clang/test/SemaCXX/gh65522.cpp @@ -0,0 +1,11 @@ +// RUN: %clang_cc1 -std=c++20 -Wc++17-compat -verify -Wno-unused %s + +class X {}; + +template<typename T> +class B3 { // expected-note {{candidate template ignored: could not match 'B3<T>' against 'int'}} + template<X x> B3(T); // expected-warning 2{{non-type template parameter of type 'X' is incompatible with C++ standards before C++20}} \ + // expected-note {{candidate template ignored: couldn't infer template argument 'x'}} +}; +B3 b3 = 0; // expected-error {{no viable constructor or deduction guide for deduction of template arguments of 'B3'}} \ + // expected-note {{while building implicit deduction guide first needed here}} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
