llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: Mariya Podchishchaeva (Fznamznon) <details> <summary>Changes</summary> Per P1975R0 an expression like static_cast<U[]>(...) defines the type of the expression as U[1]. Fixes https://github.com/llvm/llvm-project/issues/62863 --- Full diff: https://github.com/llvm/llvm-project/pull/96041.diff 3 Files Affected: - (modified) clang/docs/ReleaseNotes.rst (+2) - (modified) clang/lib/Sema/SemaType.cpp (+14) - (modified) clang/test/SemaCXX/paren-list-agg-init.cpp (+21) ``````````diff diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 7112d1f889fef..d0e5e67651364 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -695,6 +695,8 @@ Bug Fixes in This Version - Correctly reject declarations where a statement is required in C. Fixes #GH92775 +- Fixed `static_cast` to array of unknown bound. Fixes (#GH62863). + Bug Fixes to Compiler Builtins ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp index 441fdcca0758f..9bb12c6aa7b12 100644 --- a/clang/lib/Sema/SemaType.cpp +++ b/clang/lib/Sema/SemaType.cpp @@ -8771,6 +8771,20 @@ void Sema::completeExprArrayBound(Expr *E) { } } } + if (const auto CastE = dyn_cast<ExplicitCastExpr>(E)) { + QualType DestType = CastE->getTypeAsWritten(); + if (const auto *IAT = Context.getAsIncompleteArrayType(DestType)) { + // C++20 [expr.static.cast]p.4: ... If T is array of unknown bound, + // this direct-initialization defines the type of the expression + // as U[1] + QualType ResultType = Context.getConstantArrayType( + IAT->getElementType(), + llvm::APInt(Context.getTypeSize(Context.getSizeType()), 1), + /*SizeExpr=*/nullptr, ArraySizeModifier::Normal, + /*IndexTypeQuals=*/0); + E->setType(ResultType); + } + } } QualType Sema::getCompletedType(Expr *E) { diff --git a/clang/test/SemaCXX/paren-list-agg-init.cpp b/clang/test/SemaCXX/paren-list-agg-init.cpp index c1964a5a9eb00..efc1e955d4ed8 100644 --- a/clang/test/SemaCXX/paren-list-agg-init.cpp +++ b/clang/test/SemaCXX/paren-list-agg-init.cpp @@ -313,3 +313,24 @@ namespace GH63903 { constexpr S s(0); // beforecxx20-warning {{aggregate initialization of type 'const S' from a parenthesized list of values is a C++20 extension}} \ // expected-error {{constexpr variable 's' must be initialized by a constant expression}} } + + +namespace gh62863 { +int (&&arr)[] = static_cast<int[]>(42); +// beforecxx20-warning@-1 {{aggregate initialization of type 'int[1]' from a parenthesized list of values is a C++20 extension}} +int (&&arr1)[1] = static_cast<int[]>(42); +// beforecxx20-warning@-1 {{aggregate initialization of type 'int[1]' from a parenthesized list of values is a C++20 extension}} +int (&&arr2)[2] = static_cast<int[]>(42); // expected-error {{reference to type 'int[2]' could not bind to an rvalue of type 'int[1]'}} +// beforecxx20-warning@-1 {{aggregate initialization of type 'int[1]' from a parenthesized list of values is a C++20 extension}} +int (&&arr3)[3] = static_cast<int[3]>(42); +// beforecxx20-warning@-1 {{aggregate initialization of type 'int[3]' from a parenthesized list of values is a C++20 extension}} + +int (&&arr4)[] = (int[])(42); +// beforecxx20-warning@-1 {{aggregate initialization of type 'int[1]' from a parenthesized list of values is a C++20 extension}} +int (&&arr5)[1] = (int[])(42); +// beforecxx20-warning@-1 {{aggregate initialization of type 'int[1]' from a parenthesized list of values is a C++20 extension}} +int (&&arr6)[2] = (int[])(42); // expected-error {{reference to type 'int[2]' could not bind to an rvalue of type 'int[1]'}} +// beforecxx20-warning@-1 {{aggregate initialization of type 'int[1]' from a parenthesized list of values is a C++20 extension}} +int (&&arr7)[3] = (int[3])(42); +// beforecxx20-warning@-1 {{aggregate initialization of type 'int[3]' from a parenthesized list of values is a C++20 extension}} +} `````````` </details> https://github.com/llvm/llvm-project/pull/96041 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
