Author: Timm Baeder Date: 2025-04-29T08:06:31+02:00 New Revision: 0ddb5794b7b47481ed713af0add392de324d5cd2
URL: https://github.com/llvm/llvm-project/commit/0ddb5794b7b47481ed713af0add392de324d5cd2 DIFF: https://github.com/llvm/llvm-project/commit/0ddb5794b7b47481ed713af0add392de324d5cd2.diff LOG: [clang][bytecode] Remove base casts before doing memcpy (#137754) We have to copy the entire thing, not just one of the bases. Added: Modified: clang/lib/AST/ByteCode/Disasm.cpp clang/lib/AST/ByteCode/InterpBuiltin.cpp clang/test/AST/ByteCode/builtin-functions.cpp Removed: ################################################################################ diff --git a/clang/lib/AST/ByteCode/Disasm.cpp b/clang/lib/AST/ByteCode/Disasm.cpp index 83b9af9de0796..46c5cb96fa9f4 100644 --- a/clang/lib/AST/ByteCode/Disasm.cpp +++ b/clang/lib/AST/ByteCode/Disasm.cpp @@ -422,6 +422,7 @@ LLVM_DUMP_METHOD void InlineDescriptor::dump(llvm::raw_ostream &OS) const { OS << "IsActive: " << IsActive << "\n"; OS << "InUnion: " << InUnion << "\n"; OS << "IsFieldMutable: " << IsFieldMutable << "\n"; + OS << "IsArrayElement: " << IsArrayElement << "\n"; OS << "Desc: "; if (Desc) Desc->dump(OS); diff --git a/clang/lib/AST/ByteCode/InterpBuiltin.cpp b/clang/lib/AST/ByteCode/InterpBuiltin.cpp index 0b4585a10a3d5..b6e5b5ffd16ad 100644 --- a/clang/lib/AST/ByteCode/InterpBuiltin.cpp +++ b/clang/lib/AST/ByteCode/InterpBuiltin.cpp @@ -1854,8 +1854,17 @@ static bool interp__builtin_memcpy(InterpState &S, CodePtr OpPC, // Check for overlapping memory regions. if (!Move && Pointer::pointToSameBlock(SrcPtr, DestPtr)) { - unsigned SrcIndex = SrcPtr.getIndex() * SrcPtr.elemSize(); - unsigned DstIndex = DestPtr.getIndex() * DestPtr.elemSize(); + // Remove base casts. + Pointer SrcP = SrcPtr; + while (SrcP.isBaseClass()) + SrcP = SrcP.getBase(); + + Pointer DestP = DestPtr; + while (DestP.isBaseClass()) + DestP = DestP.getBase(); + + unsigned SrcIndex = SrcP.expand().getIndex() * SrcP.elemSize(); + unsigned DstIndex = DestP.expand().getIndex() * DestP.elemSize(); unsigned N = Size.getZExtValue(); if ((SrcIndex <= DstIndex && (SrcIndex + N) > DstIndex) || diff --git a/clang/test/AST/ByteCode/builtin-functions.cpp b/clang/test/AST/ByteCode/builtin-functions.cpp index a4c8ec4856ecc..f879360c5357f 100644 --- a/clang/test/AST/ByteCode/builtin-functions.cpp +++ b/clang/test/AST/ByteCode/builtin-functions.cpp @@ -1383,7 +1383,19 @@ namespace BuiltinMemcpy { static_assert(type_pun(0x3f800000) == 1.0f); // both-error {{constant}} \ // both-note {{in call}} - + struct Base { int a; }; + struct Derived : Base { int b; }; + constexpr int test_derived_to_base(int n) { + Derived arr[2] = {1, 2, 3, 4}; + Base *p = &arr[0]; + Base *q = &arr[1]; + __builtin_memcpy(p, q, sizeof(Base) * n); // both-note {{source is not a contiguous array of at least 2 elements of type 'BuiltinMemcpy::Base'}} + return arr[0].a * 1000 + arr[0].b * 100 + arr[1].a * 10 + arr[1].b; + } + static_assert(test_derived_to_base(0) == 1234); + static_assert(test_derived_to_base(1) == 3234); + static_assert(test_derived_to_base(2) == 3434); // both-error {{constant}} \ + // both-note {{in call}} } namespace Memcmp { _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
