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LLVM currently emits `.note.GNU-stack` sections on all ELF targets. However, Solaris ld doesn't know/care about them. Even worse, with the revised Solaris GNU ld patch (D85309 <https://reviews.llvm.org/D85309>), there are hundreds of warnings: /usr/gnu/bin/ld: warning: /usr/lib/amd64/crtn.o: missing .note.GNU-stack section implies executable stack /usr/gnu/bin/ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker The Solaris crts are not going to change here, and even if they were, GNU ld would emit `PT_GNU_STACK` segments that Solaris `ld.so.1` ignores. So the note sections are completely useless on Solaris and this patch disables their creation. Instead, Solaris has its own mechanisms to control stack executability: `PT_SUNW_STACK`, `DT_SUNW_SX_NXSTACK` and the system-wide control via `sxadm` where `nxstack` defaults to on. Tested on `amd64-pc-solaris2.11` and `sparcv9-sun-solaris2.11` with Solaris ld and GNU ld, and `x86_64-pc-linux-gnu`. Differential Revision: https://reviews.llvm.org/D159179
37 lines
1.2 KiB
C++
37 lines
1.2 KiB
C++
//===- MCAsmInfoELF.cpp - ELF asm properties ------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file defines target asm properties related what form asm statements
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// should take in general on ELF-based targets
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/MC/MCAsmInfoELF.h"
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#include "llvm/BinaryFormat/ELF.h"
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#include "llvm/MC/MCContext.h"
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#include "llvm/MC/MCSectionELF.h"
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using namespace llvm;
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void MCAsmInfoELF::anchor() {}
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MCSection *MCAsmInfoELF::getNonexecutableStackSection(MCContext &Ctx) const {
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// Solaris doesn't know/doesn't care about .note.GNU-stack sections, so
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// don't emit them.
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if (Ctx.getTargetTriple().isOSSolaris())
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return nullptr;
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return Ctx.getELFSection(".note.GNU-stack", ELF::SHT_PROGBITS, 0);
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}
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MCAsmInfoELF::MCAsmInfoELF() {
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HasIdentDirective = true;
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WeakRefDirective = "\t.weak\t";
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PrivateGlobalPrefix = ".L";
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PrivateLabelPrefix = ".L";
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}
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