From 7bbbf2956181f375ab193321b37ea71c5fc44054 Mon Sep 17 00:00:00 2001 From: Rainer Orth Date: Wed, 11 Aug 2021 09:27:51 +0200 Subject: [PATCH] [ELF] Don't emit SHF_GNU_RETAIN on Solaris The introduction of `SHF_GNU_RETAIN` has caused massive problems on Solaris. Initially, as reported in Bug 49437, it caused dozens of testsuite failures on both sparc and x86. The objects were marked as `ELFOSABI_NONE`, but `SHF_GNU_RETAIN` is a GNU extension. In the native Solaris ABI, that flag (in the range for OS-specific values) is `SHF_SUNW_ABSENT` with a completely different semantics, which confuses Solaris `ld` very much. Later, the objects became (correctly) marked `ELFOSABI_GNU`, which Solaris `ld` doesn't support, causing it to SEGV and break the build. The linker is currently being hardened to not accept non-native OS ABIs to avoid this. The need for linker support is already documented in `clang/include/clang/Basic/AttrDocs.td`, but not currently checked. This patch avoids all this by not emitting `SHF_GNU_RETAIN` on Solaris at all. Tested on `amd64-pc-solaris2.11`, `sparcv9-sun-solaris2.11`, and `x86_64-pc-linux-gnu`. Differential Revision: https://reviews.llvm.org/D107747 --- llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp index 0c019e7ed3b8..178dbbc8cb80 100644 --- a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp +++ b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp @@ -677,8 +677,9 @@ calcUniqueIDUpdateFlagsAndSize(const GlobalObject *GO, StringRef SectionName, } if (Retain) { - if (Ctx.getAsmInfo()->useIntegratedAssembler() || - Ctx.getAsmInfo()->binutilsIsAtLeast(2, 36)) + if ((Ctx.getAsmInfo()->useIntegratedAssembler() || + Ctx.getAsmInfo()->binutilsIsAtLeast(2, 36)) && + !TM.getTargetTriple().isOSSolaris()) Flags |= ELF::SHF_GNU_RETAIN; return NextUniqueID++; } @@ -855,8 +856,10 @@ static MCSection *selectELFSectionForGlobal( EmitUniqueSection = true; Flags |= ELF::SHF_LINK_ORDER; } - if (Retain && (Ctx.getAsmInfo()->useIntegratedAssembler() || - Ctx.getAsmInfo()->binutilsIsAtLeast(2, 36))) { + if (Retain && + (Ctx.getAsmInfo()->useIntegratedAssembler() || + Ctx.getAsmInfo()->binutilsIsAtLeast(2, 36)) && + !TM.getTargetTriple().isOSSolaris()) { EmitUniqueSection = true; Flags |= ELF::SHF_GNU_RETAIN; }