From c47fcf0ae5304127f98964817a1f1fa75eec91f3 Mon Sep 17 00:00:00 2001 From: Akira Hatanaka Date: Thu, 27 Jul 2017 18:52:44 +0000 Subject: Revert r264998 and r265035. r303175 made changes to have __cxa_allocate_exception return a 16-byte aligned pointer, so it's no longer necessary to specify a lower alignment (8-bytes) for exception objects on Darwin. rdar://problem/32363695 llvm-svn: 309308 --- clang/lib/CodeGen/ItaniumCXXABI.cpp | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'clang/lib/CodeGen') diff --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp b/clang/lib/CodeGen/ItaniumCXXABI.cpp index de9fd042a9e..c1f892a3173 100644 --- a/clang/lib/CodeGen/ItaniumCXXABI.cpp +++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp @@ -157,9 +157,17 @@ public: Address Ptr, QualType ElementType, const CXXDestructorDecl *Dtor) override; + /// Itanium says that an _Unwind_Exception has to be "double-word" + /// aligned (and thus the end of it is also so-aligned), meaning 16 + /// bytes. Of course, that was written for the actual Itanium, + /// which is a 64-bit platform. Classically, the ABI doesn't really + /// specify the alignment on other platforms, but in practice + /// libUnwind declares the struct with __attribute__((aligned)), so + /// we assume that alignment here. (It's generally 16 bytes, but + /// some targets overwrite it.) CharUnits getAlignmentOfExnObject() { - unsigned Align = CGM.getContext().getTargetInfo().getExnObjectAlignment(); - return CGM.getContext().toCharUnitsFromBits(Align); + auto align = CGM.getContext().getTargetDefaultAlignForAttributeAligned(); + return CGM.getContext().toCharUnitsFromBits(align); } void emitRethrow(CodeGenFunction &CGF, bool isNoReturn) override; -- cgit v1.2.3