100 lines
3.8 KiB
C++
100 lines
3.8 KiB
C++
//===-- llvm/Target/ARMTargetObjectFile.cpp - ARM Object Info Impl --------===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "ARMTargetObjectFile.h"
|
|
#include "ARMSubtarget.h"
|
|
#include "ARMTargetMachine.h"
|
|
#include "llvm/BinaryFormat/Dwarf.h"
|
|
#include "llvm/BinaryFormat/ELF.h"
|
|
#include "llvm/MC/MCAsmInfo.h"
|
|
#include "llvm/MC/MCContext.h"
|
|
#include "llvm/MC/MCExpr.h"
|
|
#include "llvm/MC/MCSectionELF.h"
|
|
#include "llvm/MC/MCTargetOptions.h"
|
|
#include "llvm/MC/SectionKind.h"
|
|
#include "llvm/Target/TargetMachine.h"
|
|
#include <cassert>
|
|
|
|
using namespace llvm;
|
|
using namespace dwarf;
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// ELF Target
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
void ARMElfTargetObjectFile::Initialize(MCContext &Ctx,
|
|
const TargetMachine &TM) {
|
|
const ARMBaseTargetMachine &ARM_TM = static_cast<const ARMBaseTargetMachine &>(TM);
|
|
bool isAAPCS_ABI = ARM_TM.TargetABI == ARMBaseTargetMachine::ARMABI::ARM_ABI_AAPCS;
|
|
bool genExecuteOnly =
|
|
ARM_TM.getMCSubtargetInfo()->hasFeature(ARM::FeatureExecuteOnly);
|
|
|
|
TargetLoweringObjectFileELF::Initialize(Ctx, TM);
|
|
InitializeELF(isAAPCS_ABI);
|
|
|
|
if (isAAPCS_ABI) {
|
|
LSDASection = nullptr;
|
|
}
|
|
|
|
// Make code section unreadable when in execute-only mode
|
|
if (genExecuteOnly) {
|
|
unsigned Type = ELF::SHT_PROGBITS;
|
|
unsigned Flags =
|
|
ELF::SHF_EXECINSTR | ELF::SHF_ALLOC | ELF::SHF_ARM_PURECODE;
|
|
// Since we cannot modify flags for an existing section, we create a new
|
|
// section with the right flags, and use 0 as the unique ID for
|
|
// execute-only text
|
|
TextSection = Ctx.getELFSection(".text", Type, Flags, 0, "", 0U, nullptr);
|
|
}
|
|
}
|
|
|
|
const MCExpr *ARMElfTargetObjectFile::getTTypeGlobalReference(
|
|
const GlobalValue *GV, unsigned Encoding, const TargetMachine &TM,
|
|
MachineModuleInfo *MMI, MCStreamer &Streamer) const {
|
|
if (TM.getMCAsmInfo()->getExceptionHandlingType() != ExceptionHandling::ARM)
|
|
return TargetLoweringObjectFileELF::getTTypeGlobalReference(
|
|
GV, Encoding, TM, MMI, Streamer);
|
|
|
|
assert(Encoding == DW_EH_PE_absptr && "Can handle absptr encoding only");
|
|
|
|
return MCSymbolRefExpr::create(TM.getSymbol(GV),
|
|
MCSymbolRefExpr::VK_ARM_TARGET2, getContext());
|
|
}
|
|
|
|
const MCExpr *ARMElfTargetObjectFile::
|
|
getDebugThreadLocalSymbol(const MCSymbol *Sym) const {
|
|
return MCSymbolRefExpr::create(Sym, MCSymbolRefExpr::VK_ARM_TLSLDO,
|
|
getContext());
|
|
}
|
|
|
|
static bool isExecuteOnlyFunction(const GlobalObject *GO, SectionKind SK,
|
|
const TargetMachine &TM) {
|
|
if (const Function *F = dyn_cast<Function>(GO))
|
|
if (TM.getSubtarget<ARMSubtarget>(*F).genExecuteOnly() && SK.isText())
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
MCSection *ARMElfTargetObjectFile::getExplicitSectionGlobal(
|
|
const GlobalObject *GO, SectionKind SK, const TargetMachine &TM) const {
|
|
// Set execute-only access for the explicit section
|
|
if (isExecuteOnlyFunction(GO, SK, TM))
|
|
SK = SectionKind::getExecuteOnly();
|
|
|
|
return TargetLoweringObjectFileELF::getExplicitSectionGlobal(GO, SK, TM);
|
|
}
|
|
|
|
MCSection *ARMElfTargetObjectFile::SelectSectionForGlobal(
|
|
const GlobalObject *GO, SectionKind SK, const TargetMachine &TM) const {
|
|
// Place the global in the execute-only text section
|
|
if (isExecuteOnlyFunction(GO, SK, TM))
|
|
SK = SectionKind::getExecuteOnly();
|
|
|
|
return TargetLoweringObjectFileELF::SelectSectionForGlobal(GO, SK, TM);
|
|
}
|