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//===--------- lib/ReaderWriter/ELF/ARM/ARMTargetHandler.h ----------------===//
//
// The LLVM Linker
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef LLD_READER_WRITER_ELF_ARM_ARM_TARGET_HANDLER_H
#define LLD_READER_WRITER_ELF_ARM_ARM_TARGET_HANDLER_H
#include "ARMELFFile.h"
#include "ARMRelocationHandler.h"
#include "ELFReader.h"
#include "TargetLayout.h"
namespace lld {
class ELFLinkingContext;
namespace elf {
/// \brief ARM specific section (.ARM.exidx) with indexes to exception handlers
class ARMExidxSection : public AtomSection<ELF32LE> {
typedef AtomSection<ELF32LE> Base;
public:
ARMExidxSection(const ELFLinkingContext &ctx, StringRef sectionName,
int32_t permissions, int32_t order)
: Base(ctx, sectionName, DefinedAtom::typeARMExidx, permissions, order) {
this->_type = SHT_ARM_EXIDX;
this->_isLoadedInMemory = true;
}
bool hasOutputSegment() const override { return true; }
const AtomLayout *appendAtom(const Atom *atom) override {
const DefinedAtom *definedAtom = cast<DefinedAtom>(atom);
assert(definedAtom->contentType() == DefinedAtom::typeARMExidx &&
"atom content type for .ARM.exidx section has to be typeARMExidx");
DefinedAtom::Alignment atomAlign = definedAtom->alignment();
uint64_t fOffset = alignOffset(this->fileSize(), atomAlign);
uint64_t mOffset = alignOffset(this->memSize(), atomAlign);
_atoms.push_back(new (_alloc) AtomLayout(atom, fOffset, 0));
this->_fsize = fOffset + definedAtom->size();
this->_msize = mOffset + definedAtom->size();
DEBUG_WITH_TYPE("Section", llvm::dbgs()
<< "[" << this->name() << " " << this << "] "
<< "Adding atom: " << atom->name() << "@"
<< fOffset << "\n");
uint64_t alignment = atomAlign.value;
if (this->_alignment < alignment)
this->_alignment = alignment;
return _atoms.back();
}
};
class ARMTargetLayout : public TargetLayout<ELF32LE> {
public:
ARMTargetLayout(ELFLinkingContext &ctx) : TargetLayout(ctx) {}
SectionOrder getSectionOrder(StringRef name, int32_t contentType,
int32_t contentPermissions) override {
switch (contentType) {
case DefinedAtom::typeARMExidx:
return ORDER_ARM_EXIDX;
default:
return TargetLayout::getSectionOrder(name, contentType,
contentPermissions);
}
}
StringRef getOutputSectionName(StringRef archivePath, StringRef memberPath,
StringRef inputSectionName) const override {
return llvm::StringSwitch<StringRef>(inputSectionName)
.StartsWith(".ARM.exidx", ".ARM.exidx")
.StartsWith(".ARM.extab", ".ARM.extab")
.Default(TargetLayout::getOutputSectionName(archivePath, memberPath,
inputSectionName));
}
SegmentType getSegmentType(Section<ELF32LE> *section) const override {
switch (section->order()) {
case ORDER_ARM_EXIDX:
return llvm::ELF::PT_ARM_EXIDX;
default:
return TargetLayout::getSegmentType(section);
}
}
AtomSection<ELF32LE> *
createSection(StringRef name, int32_t contentType,
DefinedAtom::ContentPermissions contentPermissions,
SectionOrder sectionOrder) override {
if (contentType == DefinedAtom::typeARMExidx)
return new ARMExidxSection(_ctx, name, contentPermissions, sectionOrder);
return TargetLayout::createSection(name, contentType, contentPermissions,
sectionOrder);
}
uint64_t getGOTSymAddr() {
std::call_once(_gotSymOnce, [this]() {
if (AtomLayout *gotAtom = findAbsoluteAtom("_GLOBAL_OFFSET_TABLE_"))
_gotSymAddr = gotAtom->_virtualAddr;
});
return _gotSymAddr;
}
uint64_t getTPOffset() {
std::call_once(_tpOffOnce, [this]() {
for (const auto &phdr : *_programHeader) {
if (phdr->p_type == llvm::ELF::PT_TLS) {
_tpOff = llvm::RoundUpToAlignment(TCB_SIZE, phdr->p_align);
break;
}
}
assert(_tpOff != 0 && "TLS segment not found");
});
return _tpOff;
}
bool target1Rel() const { return _ctx.armTarget1Rel(); }
private:
// TCB block size of the TLS.
enum { TCB_SIZE = 0x8 };
private:
uint64_t _gotSymAddr = 0;
uint64_t _tpOff = 0;
std::once_flag _gotSymOnce;
std::once_flag _tpOffOnce;
};
class ARMTargetHandler final : public TargetHandler {
public:
ARMTargetHandler(ARMLinkingContext &ctx);
const TargetRelocationHandler &getRelocationHandler() const override {
return *_relocationHandler;
}
std::unique_ptr<Reader> getObjReader() override {
return llvm::make_unique<ELFReader<ARMELFFile>>(_ctx);
}
std::unique_ptr<Reader> getDSOReader() override {
return llvm::make_unique<ELFReader<DynamicFile<ELF32LE>>>(_ctx);
}
std::unique_ptr<Writer> getWriter() override;
private:
ARMLinkingContext &_ctx;
std::unique_ptr<ARMTargetLayout> _targetLayout;
std::unique_ptr<ARMTargetRelocationHandler> _relocationHandler;
};
} // end namespace elf
} // end namespace lld
#endif // LLD_READER_WRITER_ELF_ARM_ARM_TARGET_HANDLER_H
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