Author: smeenai Date: Wed Jan 9 12:05:16 2019 New Revision: 350754 URL: http://llvm.org/viewvc/llvm-project?rev=350754&view=rev Log: [CodeGen] Clarify comment about COFF common symbol alignment
After a discussion on the commit thread, it seems the 32 byte alignment limitation is an MSVC toolchain artifact, not an inherent COFF restriction. Clarify the comment accordingly, since saying COFF in the comment but using isKnownWindowsMSVCEnvironment in the conditional is confusing. Also add a newline before the comment, which is consistent with the local style. Differential Revision: https://reviews.llvm.org/D56466 Modified: cfe/trunk/lib/CodeGen/CodeGenModule.cpp Modified: cfe/trunk/lib/CodeGen/CodeGenModule.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenModule.cpp?rev=350754&r1=350753&r2=350754&view=diff ============================================================================== --- cfe/trunk/lib/CodeGen/CodeGenModule.cpp (original) +++ cfe/trunk/lib/CodeGen/CodeGenModule.cpp Wed Jan 9 12:05:16 2019 @@ -3761,8 +3761,12 @@ static bool isVarDeclStrongDefinition(co } } } - // COFF doesn't support alignments greater than 32, so these cannot be - // in common. + + // Microsoft's link.exe doesn't support alignments greater than 32 for common + // symbols, so symbols with greater alignment requirements cannot be common. + // Other COFF linkers (ld.bfd and LLD) support arbitrary power-of-two + // alignments for common symbols via the aligncomm directive, so this + // restriction only applies to MSVC environments. if (Context.getTargetInfo().getTriple().isKnownWindowsMSVCEnvironment() && Context.getTypeAlignIfKnown(D->getType()) > 32) return true; _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
