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|
//===- lib/ReaderWriter/PECOFF/Atoms.h ------------------------------------===//
//
// The LLVM Linker
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "lld/Core/File.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/Object/COFF.h"
#include <vector>
namespace lld {
namespace coff {
class COFFDefinedAtom;
using llvm::object::COFFObjectFile;
using llvm::object::coff_section;
using llvm::object::coff_symbol;
void connectAtomsWithLayoutEdge(COFFDefinedAtom *a, COFFDefinedAtom *b);
/// A COFFReference represents relocation information for an atom. For
/// example, if atom X has a reference to atom Y with offsetInAtom=8, that
/// means that the address starting at 8th byte of the content of atom X needs
/// to be fixed up so that the address points to atom Y's address.
class COFFReference LLVM_FINAL : public Reference {
public:
COFFReference(Kind kind) : _target(nullptr), _offsetInAtom(0) {
_kind = kind;
}
COFFReference(const Atom *target, uint32_t offsetInAtom, uint16_t relocType)
: _target(target), _offsetInAtom(offsetInAtom) {
setKind(static_cast<Reference::Kind>(relocType));
}
virtual const Atom *target() const { return _target; }
virtual void setTarget(const Atom *newAtom) { _target = newAtom; }
// Addend is a value to be added to the relocation target. For example, if
// target=AtomX and addend=4, the relocation address will become the address
// of AtomX + 4. COFF does not support that sort of relocation, thus addend
// is always zero.
virtual Addend addend() const { return 0; }
virtual void setAddend(Addend) {}
virtual uint64_t offsetInAtom() const { return _offsetInAtom; }
private:
const Atom *_target;
uint32_t _offsetInAtom;
};
class COFFAbsoluteAtom : public AbsoluteAtom {
public:
COFFAbsoluteAtom(const File &f, llvm::StringRef n, const coff_symbol *s)
: _owningFile(f), _name(n), _symbol(s) {}
virtual const File &file() const { return _owningFile; }
virtual Scope scope() const {
if (_symbol->StorageClass == llvm::COFF::IMAGE_SYM_CLASS_STATIC)
return scopeTranslationUnit;
return scopeGlobal;
}
virtual llvm::StringRef name() const { return _name; }
virtual uint64_t value() const { return _symbol->Value; }
private:
const File &_owningFile;
llvm::StringRef _name;
const coff_symbol *_symbol;
};
class COFFUndefinedAtom : public UndefinedAtom {
public:
COFFUndefinedAtom(const File &f, llvm::StringRef n)
: _owningFile(f), _name(n) {}
virtual const File &file() const { return _owningFile; }
virtual llvm::StringRef name() const { return _name; }
virtual CanBeNull canBeNull() const { return CanBeNull::canBeNullNever; }
private:
const File &_owningFile;
llvm::StringRef _name;
};
class COFFDefinedAtom : public DefinedAtom {
public:
COFFDefinedAtom(const File &f, llvm::StringRef n, const coff_symbol *symb,
const coff_section *sec, llvm::ArrayRef<uint8_t> d,
StringRef sectionName, uint64_t ordinal)
: _owningFile(f), _name(n), _symbol(symb), _section(sec), _data(d),
_sectionName(sectionName), _ordinal(ordinal) {}
virtual const File &file() const { return _owningFile; }
virtual llvm::StringRef name() const { return _name; }
virtual uint64_t ordinal() const { return _ordinal; }
virtual uint64_t size() const { return _data.size(); }
uint64_t originalOffset() const { return _symbol->Value; }
void addReference(std::unique_ptr<COFFReference> reference) {
_references.push_back(std::move(reference));
}
virtual Scope scope() const {
if (!_symbol)
return scopeTranslationUnit;
switch (_symbol->StorageClass) {
case llvm::COFF::IMAGE_SYM_CLASS_EXTERNAL:
return scopeGlobal;
case llvm::COFF::IMAGE_SYM_CLASS_STATIC:
return scopeTranslationUnit;
}
llvm_unreachable("Unknown scope!");
}
virtual Interposable interposable() const { return interposeNo; }
virtual Merge merge() const { return mergeNo; }
virtual ContentType contentType() const {
if (_section->Characteristics & llvm::COFF::IMAGE_SCN_CNT_CODE)
return typeCode;
if (_section->Characteristics & llvm::COFF::IMAGE_SCN_CNT_INITIALIZED_DATA)
return typeData;
if (_section->Characteristics &
llvm::COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA)
return typeZeroFill;
return typeUnknown;
}
virtual Alignment alignment() const { return Alignment(1); }
virtual SectionChoice sectionChoice() const { return sectionBasedOnContent; }
virtual llvm::StringRef customSectionName() const { return ""; }
virtual SectionPosition sectionPosition() const { return sectionPositionAny; }
virtual DeadStripKind deadStrip() const { return deadStripNormal; }
virtual ContentPermissions permissions() const {
if (_section->Characteristics & llvm::COFF::IMAGE_SCN_MEM_READ &&
_section->Characteristics & llvm::COFF::IMAGE_SCN_MEM_WRITE)
return permRW_;
if (_section->Characteristics & llvm::COFF::IMAGE_SCN_MEM_READ &&
_section->Characteristics & llvm::COFF::IMAGE_SCN_MEM_EXECUTE)
return permR_X;
if (_section->Characteristics & llvm::COFF::IMAGE_SCN_MEM_READ)
return permR__;
return perm___;
}
virtual bool isAlias() const { return false; }
virtual StringRef getSectionName() const { return _sectionName; }
virtual llvm::ArrayRef<uint8_t> rawContent() const { return _data; }
virtual reference_iterator begin() const {
return reference_iterator(*this, reinterpret_cast<const void *>(0));
}
virtual reference_iterator end() const {
return reference_iterator(
*this, reinterpret_cast<const void *>(_references.size()));
}
private:
virtual const Reference *derefIterator(const void *iter) const {
size_t index = reinterpret_cast<size_t>(iter);
return _references[index].get();
}
virtual void incrementIterator(const void *&iter) const {
size_t index = reinterpret_cast<size_t>(iter);
iter = reinterpret_cast<const void *>(index + 1);
}
const File &_owningFile;
llvm::StringRef _name;
const coff_symbol *_symbol;
const coff_section *_section;
std::vector<std::unique_ptr<COFFReference> > _references;
llvm::ArrayRef<uint8_t> _data;
StringRef _sectionName;
uint64_t _ordinal;
};
} // namespace coff
} // namespace lld
|
