Author: ahatanak Date: Thu Feb 18 15:05:09 2016 New Revision: 261260 URL: http://llvm.org/viewvc/llvm-project?rev=261260&view=rev Log: [Sema] Fix bug in TypeLocBuilder::pushImpl
The code in TypeLocBuilder::pushImpl wasn't correctly handling the case where an element that has an 8-byte alignment was being pushed. I plan to follow up with a patch to remove redundancies and simplify the function. rdar://problem/23838912 Differential Revision: http://reviews.llvm.org/D16843 Added: cfe/trunk/test/SemaObjCXX/typeloc-data-alignment.mm Modified: cfe/trunk/lib/Sema/TypeLocBuilder.cpp Modified: cfe/trunk/lib/Sema/TypeLocBuilder.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/TypeLocBuilder.cpp?rev=261260&r1=261259&r2=261260&view=diff ============================================================================== --- cfe/trunk/lib/Sema/TypeLocBuilder.cpp (original) +++ cfe/trunk/lib/Sema/TypeLocBuilder.cpp Thu Feb 18 15:05:09 2016 @@ -115,11 +115,39 @@ TypeLoc TypeLocBuilder::pushImpl(QualTyp NumBytesAtAlign4 += LocalSize; } } else if (LocalAlignment == 8) { - if (!NumBytesAtAlign8 && NumBytesAtAlign4 % 8 != 0) { - // No existing padding and misaligned members; add in 4 bytes padding - memmove(&Buffer[Index - 4], &Buffer[Index], NumBytesAtAlign4); - Index -= 4; + if (NumBytesAtAlign8 == 0) { + // We have not seen any 8-byte aligned element yet. We insert a padding + // only if the new Index is not 8-byte-aligned. + if ((Index - LocalSize) % 8 != 0) { + memmove(&Buffer[Index - 4], &Buffer[Index], NumBytesAtAlign4); + Index -= 4; + } + } else { + unsigned Padding = NumBytesAtAlign4 % 8; + if (Padding == 0) { + if (LocalSize % 8 == 0) { + // Everything is set: there's no padding and we don't need to add + // any. + } else { + assert(LocalSize % 8 == 4); + // No existing padding; add in 4 bytes padding + memmove(&Buffer[Index - 4], &Buffer[Index], NumBytesAtAlign4); + Index -= 4; + } + } else { + assert(Padding == 4); + if (LocalSize % 8 == 0) { + // Everything is set: there's 4 bytes padding and we don't need + // to add any. + } else { + assert(LocalSize % 8 == 4); + // There are 4 bytes padding, but we don't need any; remove it. + memmove(&Buffer[Index + 4], &Buffer[Index], NumBytesAtAlign4); + Index += 4; + } + } } + // Forget about any padding. NumBytesAtAlign4 = 0; NumBytesAtAlign8 += LocalSize; Added: cfe/trunk/test/SemaObjCXX/typeloc-data-alignment.mm URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaObjCXX/typeloc-data-alignment.mm?rev=261260&view=auto ============================================================================== --- cfe/trunk/test/SemaObjCXX/typeloc-data-alignment.mm (added) +++ cfe/trunk/test/SemaObjCXX/typeloc-data-alignment.mm Thu Feb 18 15:05:09 2016 @@ -0,0 +1,12 @@ +// RUN: %clang_cc1 -fsyntax-only -verify %s +// expected-no-diagnostics + +// Make sure this doesn't crash. + +@protocol P +@end +template <class T> +id<P> foo(T) { + int i; + foo(i); +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
