llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: Alejandro Álvarez Ayllón (alejandro-alvarez-sonarsource) <details> <summary>Changes</summary> A constructor may have failed to be used due to a broken templated dependent parameter. The `InitializationSequence` itself can succeed. Due to the assumption that it is in a failed state, it can either cause an assertion failure, or undefined behavior in release mode, since `sequence.Failure` is not initialized. --- Full diff: https://github.com/llvm/llvm-project/pull/108021.diff 2 Files Affected: - (modified) clang/lib/Sema/SemaCast.cpp (+6-1) - (added) clang/test/Parser/cxx-bad-cast-diagnose-broken-template.cpp (+31) ``````````diff diff --git a/clang/lib/Sema/SemaCast.cpp b/clang/lib/Sema/SemaCast.cpp index f01b22a72915c8..6ac6201843476b 100644 --- a/clang/lib/Sema/SemaCast.cpp +++ b/clang/lib/Sema/SemaCast.cpp @@ -446,7 +446,12 @@ static bool tryDiagnoseOverloadedCast(Sema &S, CastType CT, : InitializationKind::CreateCast(/*type range?*/ range); InitializationSequence sequence(S, entity, initKind, src); - assert(sequence.Failed() && "initialization succeeded on second try?"); + // It could happen that a constructor failed to be used because + // it requires a temporary of a broken type. Still, it will be found when + // looking for a match. + if (!sequence.Failed()) + return false; + switch (sequence.getFailureKind()) { default: return false; diff --git a/clang/test/Parser/cxx-bad-cast-diagnose-broken-template.cpp b/clang/test/Parser/cxx-bad-cast-diagnose-broken-template.cpp new file mode 100644 index 00000000000000..f9fc3e6082da10 --- /dev/null +++ b/clang/test/Parser/cxx-bad-cast-diagnose-broken-template.cpp @@ -0,0 +1,31 @@ +// RUN: %clang_cc1 -fcxx-exceptions -fexceptions -fsyntax-only -verify %s + +template< typename> +struct IsConstCharArray +{ + static const bool value = false; +}; + +template< int N > +struct IsConstCharArray< const char[ N ] > +{ + typedef char CharType; + static const bool value = true; + static const missing_int_t length = N - 1; // expected-error {{unknown type name 'missing_int_t'}} +}; + +class String { +public: + template <typename T> + String(T& str, typename IsConstCharArray<T>::CharType = 0); +}; + + +class Exception { +public: + Exception(String const&); +}; + +void foo() { + throw Exception("some error"); // expected-error {{functional-style cast from 'const char[11]' to 'Exception' is not allowed}} +} `````````` </details> https://github.com/llvm/llvm-project/pull/108021 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
