Author: Timm Baeder Date: 2025-07-22T14:23:01+02:00 New Revision: a5d9ba66258e452e4658281bbbd07a2214d4dc51
URL: https://github.com/llvm/llvm-project/commit/a5d9ba66258e452e4658281bbbd07a2214d4dc51 DIFF: https://github.com/llvm/llvm-project/commit/a5d9ba66258e452e4658281bbbd07a2214d4dc51.diff LOG: [clang][bytecode] Error on bitcasts to bool that aren't 0 or 1 (#149996) This is also what the current interpreter does. Added: Modified: clang/lib/AST/ByteCode/Interp.h clang/test/AST/ByteCode/builtin-bit-cast.cpp Removed: ################################################################################ diff --git a/clang/lib/AST/ByteCode/Interp.h b/clang/lib/AST/ByteCode/Interp.h index 7f29200f8617f..b42c7665c3a35 100644 --- a/clang/lib/AST/ByteCode/Interp.h +++ b/clang/lib/AST/ByteCode/Interp.h @@ -3557,12 +3557,22 @@ inline bool BitCastPrim(InterpState &S, CodePtr OpPC, bool TargetIsUCharOrByte, Floating Result = S.allocFloat(*Sem); Floating::bitcastFromMemory(Buff.data(), *Sem, &Result); S.Stk.push<Floating>(Result); - - // S.Stk.push<Floating>(T::bitcastFromMemory(Buff.data(), *Sem)); } else if constexpr (needsAlloc<T>()) { T Result = S.allocAP<T>(ResultBitWidth); T::bitcastFromMemory(Buff.data(), ResultBitWidth, &Result); S.Stk.push<T>(Result); + } else if constexpr (std::is_same_v<T, Boolean>) { + // Only allow to cast single-byte integers to bool if they are either 0 + // or 1. + assert(FullBitWidth.getQuantity() == 8); + auto Val = static_cast<unsigned int>(Buff[0]); + if (Val > 1) { + S.FFDiag(S.Current->getSource(OpPC), + diag::note_constexpr_bit_cast_unrepresentable_value) + << S.getASTContext().BoolTy << Val; + return false; + } + S.Stk.push<T>(T::bitcastFromMemory(Buff.data(), ResultBitWidth)); } else { assert(!Sem); S.Stk.push<T>(T::bitcastFromMemory(Buff.data(), ResultBitWidth)); diff --git a/clang/test/AST/ByteCode/builtin-bit-cast.cpp b/clang/test/AST/ByteCode/builtin-bit-cast.cpp index 3c5e89d7d5a74..bc356b0b6e122 100644 --- a/clang/test/AST/ByteCode/builtin-bit-cast.cpp +++ b/clang/test/AST/ByteCode/builtin-bit-cast.cpp @@ -22,6 +22,10 @@ typedef __INTPTR_TYPE__ intptr_t; static_assert(sizeof(int) == 4); static_assert(sizeof(long long) == 8); + +constexpr bool test_bad_bool = __builtin_bit_cast(bool, (char)0xff); // both-error {{must be initialized by a constant expression}} \ + // both-note {{value 255 cannot be represented in type 'bool'}} + template <class To, class From> constexpr To bit_cast(const From &from) { static_assert(sizeof(To) == sizeof(From)); _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
