diff options
| -rw-r--r-- | lib/AST/RecordLayoutBuilder.cpp | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/lib/AST/RecordLayoutBuilder.cpp b/lib/AST/RecordLayoutBuilder.cpp index 7c0c8088e8..6b8d7cf22d 100644 --- a/lib/AST/RecordLayoutBuilder.cpp +++ b/lib/AST/RecordLayoutBuilder.cpp @@ -415,7 +415,14 @@ EmptySubobjectMap::CanPlaceFieldAtOffset(const FieldDecl *FD, uint64_t Offset) { void EmptySubobjectMap::UpdateEmptyFieldSubobjects(const CXXRecordDecl *RD, const CXXRecordDecl *Class, uint64_t Offset) { - + // We know that the only empty subobjects that can conflict with empty + // field subobjects are subobjects empty bases that can be placed at offset + // zero. Because of this, we only need to keep track of empty field + // subobjects with offsets less than the size of the largest empty + // subobject for our class. + if (Offset >= SizeOfLargestEmptySubobject) + return; + AddSubobjectAtOffset(RD, Offset); const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD); @@ -480,6 +487,14 @@ void EmptySubobjectMap::UpdateEmptyFieldSubobjects(const FieldDecl *FD, uint64_t ElementOffset = Offset; for (uint64_t I = 0; I != NumElements; ++I) { + // We know that the only empty subobjects that can conflict with empty + // field subobjects are subobjects empty bases that can be placed at + // offset zero. Because of this, we only need to keep track of empty field + // subobjects with offsets less than the size of the largest empty + // subobject for our class. + if (ElementOffset >= SizeOfLargestEmptySubobject) + return; + UpdateEmptyFieldSubobjects(RD, RD, ElementOffset); ElementOffset += Layout.getSize(); } |