Author: Timm Baeder Date: 2025-05-15T13:17:29+02:00 New Revision: 767a203a9e61e307086be96288947d130367a267
URL: https://github.com/llvm/llvm-project/commit/767a203a9e61e307086be96288947d130367a267 DIFF: https://github.com/llvm/llvm-project/commit/767a203a9e61e307086be96288947d130367a267.diff LOG: [clang][bytecode] Fix discarded LValueToRValueBitCasts (#140034) We handle discarding fine, but we used to ignore all discarded cast expressions. Handle bitcasts differently. Added: Modified: clang/lib/AST/ByteCode/Compiler.cpp clang/lib/AST/ByteCode/Compiler.h clang/test/AST/ByteCode/builtin-bit-cast.cpp Removed: ################################################################################ diff --git a/clang/lib/AST/ByteCode/Compiler.cpp b/clang/lib/AST/ByteCode/Compiler.cpp index 67b6ae4a393e9..2580fb17ce5e3 100644 --- a/clang/lib/AST/ByteCode/Compiler.cpp +++ b/clang/lib/AST/ByteCode/Compiler.cpp @@ -474,10 +474,6 @@ bool Compiler<Emitter>::VisitCastExpr(const CastExpr *CE) { return false; return this->emitDecayPtr(*FromT, *ToT, CE); } - - case CK_LValueToRValueBitCast: - return this->emitBuiltinBitCast(CE); - case CK_IntegralToBoolean: case CK_FixedPointToBoolean: { // HLSL uses this to cast to one-element vectors. @@ -735,6 +731,11 @@ bool Compiler<Emitter>::VisitCastExpr(const CastExpr *CE) { llvm_unreachable("Unhandled clang::CastKind enum"); } +template <class Emitter> +bool Compiler<Emitter>::VisitBuiltinBitCastExpr(const BuiltinBitCastExpr *E) { + return this->emitBuiltinBitCast(E); +} + template <class Emitter> bool Compiler<Emitter>::VisitIntegerLiteral(const IntegerLiteral *LE) { if (DiscardResult) diff --git a/clang/lib/AST/ByteCode/Compiler.h b/clang/lib/AST/ByteCode/Compiler.h index ec5bd637453c5..56a972f452af9 100644 --- a/clang/lib/AST/ByteCode/Compiler.h +++ b/clang/lib/AST/ByteCode/Compiler.h @@ -126,6 +126,7 @@ class Compiler : public ConstStmtVisitor<Compiler<Emitter>, bool>, // Expressions. bool VisitCastExpr(const CastExpr *E); + bool VisitBuiltinBitCastExpr(const BuiltinBitCastExpr *E); bool VisitIntegerLiteral(const IntegerLiteral *E); bool VisitFloatingLiteral(const FloatingLiteral *E); bool VisitImaginaryLiteral(const ImaginaryLiteral *E); diff --git a/clang/test/AST/ByteCode/builtin-bit-cast.cpp b/clang/test/AST/ByteCode/builtin-bit-cast.cpp index 187f180afd3da..3c5e89d7d5a74 100644 --- a/clang/test/AST/ByteCode/builtin-bit-cast.cpp +++ b/clang/test/AST/ByteCode/builtin-bit-cast.cpp @@ -503,6 +503,16 @@ namespace OversizedBitField { #endif } +namespace Discarded { + enum my_byte : unsigned char {}; + struct pad { + char a; + int b; + }; + constexpr int bad_my_byte = (__builtin_bit_cast(my_byte[8], pad{1, 2}), 0); // both-error {{must be initialized by a constant expression}} \ + // both-note {{indeterminate value can only initialize an object of type 'unsigned char' or 'std::byte';}} +} + typedef bool bool9 __attribute__((ext_vector_type(9))); // both-error@+2 {{constexpr variable 'bad_bool9_to_short' must be initialized by a constant expression}} // both-note@+1 {{bit_cast involving type 'bool __attribute__((ext_vector_type(9)))' (vector of 9 'bool' values) is not allowed in a constant expression; element size 1 * element count 9 is not a multiple of the byte size 8}} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
