forked from OSchip/llvm-project
109 lines
3.8 KiB
C++
109 lines
3.8 KiB
C++
//===-- X86TargetObjectFile.cpp - X86 Object Info -------------------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "X86TargetObjectFile.h"
|
|
#include "llvm/IR/Mangler.h"
|
|
#include "llvm/IR/Operator.h"
|
|
#include "llvm/MC/MCContext.h"
|
|
#include "llvm/MC/MCExpr.h"
|
|
#include "llvm/MC/MCSectionELF.h"
|
|
#include "llvm/Support/Dwarf.h"
|
|
#include "llvm/Target/TargetLowering.h"
|
|
|
|
using namespace llvm;
|
|
using namespace dwarf;
|
|
|
|
const MCExpr *X86_64MachoTargetObjectFile::getTTypeGlobalReference(
|
|
const GlobalValue *GV, unsigned Encoding, Mangler &Mang,
|
|
const TargetMachine &TM, MachineModuleInfo *MMI,
|
|
MCStreamer &Streamer) const {
|
|
|
|
// On Darwin/X86-64, we can reference dwarf symbols with foo@GOTPCREL+4, which
|
|
// is an indirect pc-relative reference.
|
|
if (Encoding & (DW_EH_PE_indirect | DW_EH_PE_pcrel)) {
|
|
const MCSymbol *Sym = TM.getSymbol(GV, Mang);
|
|
const MCExpr *Res =
|
|
MCSymbolRefExpr::Create(Sym, MCSymbolRefExpr::VK_GOTPCREL, getContext());
|
|
const MCExpr *Four = MCConstantExpr::Create(4, getContext());
|
|
return MCBinaryExpr::CreateAdd(Res, Four, getContext());
|
|
}
|
|
|
|
return TargetLoweringObjectFileMachO::getTTypeGlobalReference(
|
|
GV, Encoding, Mang, TM, MMI, Streamer);
|
|
}
|
|
|
|
MCSymbol *X86_64MachoTargetObjectFile::getCFIPersonalitySymbol(
|
|
const GlobalValue *GV, Mangler &Mang, const TargetMachine &TM,
|
|
MachineModuleInfo *MMI) const {
|
|
return TM.getSymbol(GV, Mang);
|
|
}
|
|
|
|
void
|
|
X86LinuxTargetObjectFile::Initialize(MCContext &Ctx, const TargetMachine &TM) {
|
|
TargetLoweringObjectFileELF::Initialize(Ctx, TM);
|
|
InitializeELF(TM.Options.UseInitArray);
|
|
}
|
|
|
|
const MCExpr *
|
|
X86LinuxTargetObjectFile::getDebugThreadLocalSymbol(
|
|
const MCSymbol *Sym) const {
|
|
return MCSymbolRefExpr::Create(Sym, MCSymbolRefExpr::VK_DTPOFF, getContext());
|
|
}
|
|
|
|
const MCExpr *X86WindowsTargetObjectFile::getExecutableRelativeSymbol(
|
|
const ConstantExpr *CE, Mangler &Mang, const TargetMachine &TM) const {
|
|
// We are looking for the difference of two symbols, need a subtraction
|
|
// operation.
|
|
const SubOperator *Sub = dyn_cast<SubOperator>(CE);
|
|
if (!Sub)
|
|
return 0;
|
|
|
|
// Symbols must first be numbers before we can subtract them, we need to see a
|
|
// ptrtoint on both subtraction operands.
|
|
const PtrToIntOperator *SubLHS =
|
|
dyn_cast<PtrToIntOperator>(Sub->getOperand(0));
|
|
const PtrToIntOperator *SubRHS =
|
|
dyn_cast<PtrToIntOperator>(Sub->getOperand(1));
|
|
if (!SubLHS || !SubRHS)
|
|
return 0;
|
|
|
|
// Our symbols should exist in address space zero, cowardly no-op if
|
|
// otherwise.
|
|
if (SubLHS->getPointerAddressSpace() != 0 ||
|
|
SubRHS->getPointerAddressSpace() != 0)
|
|
return 0;
|
|
|
|
// Both ptrtoint instructions must wrap global variables:
|
|
// - Only global variables are eligible for image relative relocations.
|
|
// - The subtrahend refers to the special symbol __ImageBase, a global.
|
|
const GlobalVariable *GVLHS =
|
|
dyn_cast<GlobalVariable>(SubLHS->getPointerOperand());
|
|
const GlobalVariable *GVRHS =
|
|
dyn_cast<GlobalVariable>(SubRHS->getPointerOperand());
|
|
if (!GVLHS || !GVRHS)
|
|
return 0;
|
|
|
|
// We expect __ImageBase to be a global variable without a section, externally
|
|
// defined.
|
|
//
|
|
// It should look something like this: @__ImageBase = external constant i8
|
|
if (GVRHS->isThreadLocal() || GVRHS->getName() != "__ImageBase" ||
|
|
!GVRHS->hasExternalLinkage() || GVRHS->hasInitializer() ||
|
|
GVRHS->hasSection())
|
|
return 0;
|
|
|
|
// An image-relative, thread-local, symbol makes no sense.
|
|
if (GVLHS->isThreadLocal())
|
|
return 0;
|
|
|
|
return MCSymbolRefExpr::Create(TM.getSymbol(GVLHS, Mang),
|
|
MCSymbolRefExpr::VK_COFF_IMGREL32,
|
|
getContext());
|
|
}
|