Viewing file:  ObjectFile.h (21.4 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
//===- ObjectFile.h - File format independent object file -------*- C++ -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This file declares a file format independent ObjectFile class.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_OBJECT_OBJECTFILE_H
#define LLVM_OBJECT_OBJECTFILE_H
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/Hashing.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/iterator_range.h"
#include "llvm/BinaryFormat/Magic.h"
#include "llvm/BinaryFormat/Swift.h"
#include "llvm/Object/Binary.h"
#include "llvm/Object/Error.h"
#include "llvm/Object/SymbolicFile.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/MemoryBufferRef.h"
#include "llvm/TargetParser/Triple.h"
#include <cassert>
#include <cstdint>
#include <memory>
namespace llvm {
class SubtargetFeatures;
namespace object {
class COFFObjectFile;
class MachOObjectFile;
class ObjectFile;
class SectionRef;
class SymbolRef;
class symbol_iterator;
class WasmObjectFile;
using section_iterator = content_iterator<SectionRef>;
typedef std::function<bool(const SectionRef &)> SectionFilterPredicate;
/// This is a value type class that represents a single relocation in the list
/// of relocations in the object file.
class RelocationRef {
DataRefImpl RelocationPimpl;
const ObjectFile *OwningObject = nullptr;
public:
RelocationRef() = default;
RelocationRef(DataRefImpl RelocationP, const ObjectFile *Owner);
bool operator==(const RelocationRef &Other) const;
void moveNext();
uint64_t getOffset() const;
symbol_iterator getSymbol() const;
uint64_t getType() const;
/// Get a string that represents the type of this relocation.
///
/// This is for display purposes only.
void getTypeName(SmallVectorImpl<char> &Result) const;
DataRefImpl getRawDataRefImpl() const;
const ObjectFile *getObject() const;
};
using relocation_iterator = content_iterator<RelocationRef>;
/// This is a value type class that represents a single section in the list of
/// sections in the object file.
class SectionRef {
friend class SymbolRef;
DataRefImpl SectionPimpl;
const ObjectFile *OwningObject = nullptr;
public:
SectionRef() = default;
SectionRef(DataRefImpl SectionP, const ObjectFile *Owner);
bool operator==(const SectionRef &Other) const;
bool operator!=(const SectionRef &Other) const;
bool operator<(const SectionRef &Other) const;
void moveNext();
Expected<StringRef> getName() const;
uint64_t getAddress() const;
uint64_t getIndex() const;
uint64_t getSize() const;
Expected<StringRef> getContents() const;
/// Get the alignment of this section.
Align getAlignment() const;
bool isCompressed() const;
/// Whether this section contains instructions.
bool isText() const;
/// Whether this section contains data, not instructions.
bool isData() const;
/// Whether this section contains BSS uninitialized data.
bool isBSS() const;
bool isVirtual() const;
bool isBitcode() const;
bool isStripped() const;
/// Whether this section will be placed in the text segment, according to the
/// Berkeley size format. This is true if the section is allocatable, and
/// contains either code or readonly data.
bool isBerkeleyText() const;
/// Whether this section will be placed in the data segment, according to the
/// Berkeley size format. This is true if the section is allocatable and
/// contains data (e.g. PROGBITS), but is not text.
bool isBerkeleyData() const;
/// Whether this section is a debug section.
bool isDebugSection() const;
bool containsSymbol(SymbolRef S) const;
relocation_iterator relocation_begin() const;
relocation_iterator relocation_end() const;
iterator_range<relocation_iterator> relocations() const {
return make_range(relocation_begin(), relocation_end());
}
/// Returns the related section if this section contains relocations. The
/// returned section may or may not have applied its relocations.
Expected<section_iterator> getRelocatedSection() const;
DataRefImpl getRawDataRefImpl() const;
const ObjectFile *getObject() const;
};
struct SectionedAddress {
const static uint64_t UndefSection = UINT64_MAX;
uint64_t Address = 0;
uint64_t SectionIndex = UndefSection;
};
inline bool operator<(const SectionedAddress &LHS,
const SectionedAddress &RHS) {
return std::tie(LHS.SectionIndex, LHS.Address) <
std::tie(RHS.SectionIndex, RHS.Address);
}
inline bool operator==(const SectionedAddress &LHS,
const SectionedAddress &RHS) {
return std::tie(LHS.SectionIndex, LHS.Address) ==
std::tie(RHS.SectionIndex, RHS.Address);
}
raw_ostream &operator<<(raw_ostream &OS, const SectionedAddress &Addr);
/// This is a value type class that represents a single symbol in the list of
/// symbols in the object file.
class SymbolRef : public BasicSymbolRef {
friend class SectionRef;
public:
enum Type {
ST_Unknown, // Type not specified
ST_Other,
ST_Data,
ST_Debug,
ST_File,
ST_Function,
};
SymbolRef() = default;
SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner);
SymbolRef(const BasicSymbolRef &B) : BasicSymbolRef(B) {
assert(isa<ObjectFile>(BasicSymbolRef::getObject()));
}
Expected<StringRef> getName() const;
/// Returns the symbol virtual address (i.e. address at which it will be
/// mapped).
Expected<uint64_t> getAddress() const;
/// Return the value of the symbol depending on the object this can be an
/// offset or a virtual address.
Expected<uint64_t> getValue() const;
/// Get the alignment of this symbol as the actual value (not log 2).
uint32_t getAlignment() const;
uint64_t getCommonSize() const;
Expected<SymbolRef::Type> getType() const;
/// Get section this symbol is defined in reference to. Result is
/// end_sections() if it is undefined or is an absolute symbol.
Expected<section_iterator> getSection() const;
const ObjectFile *getObject() const;
};
class symbol_iterator : public basic_symbol_iterator {
public:
symbol_iterator(SymbolRef Sym) : basic_symbol_iterator(Sym) {}
symbol_iterator(const basic_symbol_iterator &B)
: basic_symbol_iterator(SymbolRef(B->getRawDataRefImpl(),
cast<ObjectFile>(B->getObject()))) {}
const SymbolRef *operator->() const {
const BasicSymbolRef &P = basic_symbol_iterator::operator *();
return static_cast<const SymbolRef*>(&P);
}
const SymbolRef &operator*() const {
const BasicSymbolRef &P = basic_symbol_iterator::operator *();
return static_cast<const SymbolRef&>(P);
}
};
/// This class is the base class for all object file types. Concrete instances
/// of this object are created by createObjectFile, which figures out which type
/// to create.
class ObjectFile : public SymbolicFile {
virtual void anchor();
protected:
ObjectFile(unsigned int Type, MemoryBufferRef Source);
const uint8_t *base() const {
return reinterpret_cast<const uint8_t *>(Data.getBufferStart());
}
// These functions are for SymbolRef to call internally. The main goal of
// this is to allow SymbolRef::SymbolPimpl to point directly to the symbol
// entry in the memory mapped object file. SymbolPimpl cannot contain any
// virtual functions because then it could not point into the memory mapped
// file.
//
// Implementations assume that the DataRefImpl is valid and has not been
// modified externally. It's UB otherwise.
friend class SymbolRef;
virtual Expected<StringRef> getSymbolName(DataRefImpl Symb) const = 0;
Error printSymbolName(raw_ostream &OS,
DataRefImpl Symb) const override;
virtual Expected<uint64_t> getSymbolAddress(DataRefImpl Symb) const = 0;
virtual uint64_t getSymbolValueImpl(DataRefImpl Symb) const = 0;
virtual uint32_t getSymbolAlignment(DataRefImpl Symb) const;
virtual uint64_t getCommonSymbolSizeImpl(DataRefImpl Symb) const = 0;
virtual Expected<SymbolRef::Type> getSymbolType(DataRefImpl Symb) const = 0;
virtual Expected<section_iterator>
getSymbolSection(DataRefImpl Symb) const = 0;
// Same as above for SectionRef.
friend class SectionRef;
virtual void moveSectionNext(DataRefImpl &Sec) const = 0;
virtual Expected<StringRef> getSectionName(DataRefImpl Sec) const = 0;
virtual uint64_t getSectionAddress(DataRefImpl Sec) const = 0;
virtual uint64_t getSectionIndex(DataRefImpl Sec) const = 0;
virtual uint64_t getSectionSize(DataRefImpl Sec) const = 0;
virtual Expected<ArrayRef<uint8_t>>
getSectionContents(DataRefImpl Sec) const = 0;
virtual uint64_t getSectionAlignment(DataRefImpl Sec) const = 0;
virtual bool isSectionCompressed(DataRefImpl Sec) const = 0;
virtual bool isSectionText(DataRefImpl Sec) const = 0;
virtual bool isSectionData(DataRefImpl Sec) const = 0;
virtual bool isSectionBSS(DataRefImpl Sec) const = 0;
// A section is 'virtual' if its contents aren't present in the object image.
virtual bool isSectionVirtual(DataRefImpl Sec) const = 0;
virtual bool isSectionBitcode(DataRefImpl Sec) const;
virtual bool isSectionStripped(DataRefImpl Sec) const;
virtual bool isBerkeleyText(DataRefImpl Sec) const;
virtual bool isBerkeleyData(DataRefImpl Sec) const;
virtual bool isDebugSection(DataRefImpl Sec) const;
virtual relocation_iterator section_rel_begin(DataRefImpl Sec) const = 0;
virtual relocation_iterator section_rel_end(DataRefImpl Sec) const = 0;
virtual Expected<section_iterator> getRelocatedSection(DataRefImpl Sec) const;
// Same as above for RelocationRef.
friend class RelocationRef;
virtual void moveRelocationNext(DataRefImpl &Rel) const = 0;
virtual uint64_t getRelocationOffset(DataRefImpl Rel) const = 0;
virtual symbol_iterator getRelocationSymbol(DataRefImpl Rel) const = 0;
virtual uint64_t getRelocationType(DataRefImpl Rel) const = 0;
virtual void getRelocationTypeName(DataRefImpl Rel,
SmallVectorImpl<char> &Result) const = 0;
virtual llvm::binaryformat::Swift5ReflectionSectionKind
mapReflectionSectionNameToEnumValue(StringRef SectionName) const {
return llvm::binaryformat::Swift5ReflectionSectionKind::unknown;
};
Expected<uint64_t> getSymbolValue(DataRefImpl Symb) const;
public:
ObjectFile() = delete;
ObjectFile(const ObjectFile &other) = delete;
ObjectFile &operator=(const ObjectFile &other) = delete;
uint64_t getCommonSymbolSize(DataRefImpl Symb) const {
Expected<uint32_t> SymbolFlagsOrErr = getSymbolFlags(Symb);
if (!SymbolFlagsOrErr)
// TODO: Actually report errors helpfully.
report_fatal_error(SymbolFlagsOrErr.takeError());
assert(*SymbolFlagsOrErr & SymbolRef::SF_Common);
return getCommonSymbolSizeImpl(Symb);
}
virtual std::vector<SectionRef> dynamic_relocation_sections() const {
return std::vector<SectionRef>();
}
using symbol_iterator_range = iterator_range<symbol_iterator>;
symbol_iterator_range symbols() const {
return symbol_iterator_range(symbol_begin(), symbol_end());
}
virtual section_iterator section_begin() const = 0;
virtual section_iterator section_end() const = 0;
using section_iterator_range = iterator_range<section_iterator>;
section_iterator_range sections() const {
return section_iterator_range(section_begin(), section_end());
}
virtual bool hasDebugInfo() const;
/// The number of bytes used to represent an address in this object
/// file format.
virtual uint8_t getBytesInAddress() const = 0;
virtual StringRef getFileFormatName() const = 0;
virtual Triple::ArchType getArch() const = 0;
virtual Triple::OSType getOS() const { return Triple::UnknownOS; }
virtual Expected<SubtargetFeatures> getFeatures() const = 0;
virtual std::optional<StringRef> tryGetCPUName() const {
return std::nullopt;
};
virtual void setARMSubArch(Triple &TheTriple) const { }
virtual Expected<uint64_t> getStartAddress() const {
return errorCodeToError(object_error::parse_failed);
};
/// Create a triple from the data in this object file.
Triple makeTriple() const;
/// Maps a debug section name to a standard DWARF section name.
virtual StringRef mapDebugSectionName(StringRef Name) const { return Name; }
/// True if this is a relocatable object (.o/.obj).
virtual bool isRelocatableObject() const = 0;
/// True if the reflection section can be stripped by the linker.
bool isReflectionSectionStrippable(
llvm::binaryformat::Swift5ReflectionSectionKind ReflectionSectionKind)
const;
/// @returns Pointer to ObjectFile subclass to handle this type of object.
/// @param ObjectPath The path to the object file. ObjectPath.isObject must
/// return true.
/// Create ObjectFile from path.
static Expected<OwningBinary<ObjectFile>>
createObjectFile(StringRef ObjectPath);
static Expected<std::unique_ptr<ObjectFile>>
createObjectFile(MemoryBufferRef Object, llvm::file_magic Type,
bool InitContent = true);
static Expected<std::unique_ptr<ObjectFile>>
createObjectFile(MemoryBufferRef Object) {
return createObjectFile(Object, llvm::file_magic::unknown);
}
static bool classof(const Binary *v) {
return v->isObject();
}
static Expected<std::unique_ptr<COFFObjectFile>>
createCOFFObjectFile(MemoryBufferRef Object);
static Expected<std::unique_ptr<ObjectFile>>
createXCOFFObjectFile(MemoryBufferRef Object, unsigned FileType);
static Expected<std::unique_ptr<ObjectFile>>
createELFObjectFile(MemoryBufferRef Object, bool InitContent = true);
static Expected<std::unique_ptr<MachOObjectFile>>
createMachOObjectFile(MemoryBufferRef Object, uint32_t UniversalCputype = 0,
uint32_t UniversalIndex = 0,
size_t MachOFilesetEntryOffset = 0);
static Expected<std::unique_ptr<ObjectFile>>
createGOFFObjectFile(MemoryBufferRef Object);
static Expected<std::unique_ptr<WasmObjectFile>>
createWasmObjectFile(MemoryBufferRef Object);
};
/// A filtered iterator for SectionRefs that skips sections based on some given
/// predicate.
class SectionFilterIterator {
public:
SectionFilterIterator(SectionFilterPredicate Pred,
const section_iterator &Begin,
const section_iterator &End)
: Predicate(std::move(Pred)), Iterator(Begin), End(End) {
scanPredicate();
}
const SectionRef &operator*() const { return *Iterator; }
SectionFilterIterator &operator++() {
++Iterator;
scanPredicate();
return *this;
}
bool operator!=(const SectionFilterIterator &Other) const {
return Iterator != Other.Iterator;
}
private:
void scanPredicate() {
while (Iterator != End && !Predicate(*Iterator)) {
++Iterator;
}
}
SectionFilterPredicate Predicate;
section_iterator Iterator;
section_iterator End;
};
/// Creates an iterator range of SectionFilterIterators for a given Object and
/// predicate.
class SectionFilter {
public:
SectionFilter(SectionFilterPredicate Pred, const ObjectFile &Obj)
: Predicate(std::move(Pred)), Object(Obj) {}
SectionFilterIterator begin() {
return SectionFilterIterator(Predicate, Object.section_begin(),
Object.section_end());
}
SectionFilterIterator end() {
return SectionFilterIterator(Predicate, Object.section_end(),
Object.section_end());
}
private:
SectionFilterPredicate Predicate;
const ObjectFile &Object;
};
// Inline function definitions.
inline SymbolRef::SymbolRef(DataRefImpl SymbolP, const ObjectFile *Owner)
: BasicSymbolRef(SymbolP, Owner) {}
inline Expected<StringRef> SymbolRef::getName() const {
return getObject()->getSymbolName(getRawDataRefImpl());
}
inline Expected<uint64_t> SymbolRef::getAddress() const {
return getObject()->getSymbolAddress(getRawDataRefImpl());
}
inline Expected<uint64_t> SymbolRef::getValue() const {
return getObject()->getSymbolValue(getRawDataRefImpl());
}
inline uint32_t SymbolRef::getAlignment() const {
return getObject()->getSymbolAlignment(getRawDataRefImpl());
}
inline uint64_t SymbolRef::getCommonSize() const {
return getObject()->getCommonSymbolSize(getRawDataRefImpl());
}
inline Expected<section_iterator> SymbolRef::getSection() const {
return getObject()->getSymbolSection(getRawDataRefImpl());
}
inline Expected<SymbolRef::Type> SymbolRef::getType() const {
return getObject()->getSymbolType(getRawDataRefImpl());
}
inline const ObjectFile *SymbolRef::getObject() const {
const SymbolicFile *O = BasicSymbolRef::getObject();
return cast<ObjectFile>(O);
}
/// SectionRef
inline SectionRef::SectionRef(DataRefImpl SectionP,
const ObjectFile *Owner)
: SectionPimpl(SectionP)
, OwningObject(Owner) {}
inline bool SectionRef::operator==(const SectionRef &Other) const {
return OwningObject == Other.OwningObject &&
SectionPimpl == Other.SectionPimpl;
}
inline bool SectionRef::operator!=(const SectionRef &Other) const {
return !(*this == Other);
}
inline bool SectionRef::operator<(const SectionRef &Other) const {
assert(OwningObject == Other.OwningObject);
return SectionPimpl < Other.SectionPimpl;
}
inline void SectionRef::moveNext() {
return OwningObject->moveSectionNext(SectionPimpl);
}
inline Expected<StringRef> SectionRef::getName() const {
return OwningObject->getSectionName(SectionPimpl);
}
inline uint64_t SectionRef::getAddress() const {
return OwningObject->getSectionAddress(SectionPimpl);
}
inline uint64_t SectionRef::getIndex() const {
return OwningObject->getSectionIndex(SectionPimpl);
}
inline uint64_t SectionRef::getSize() const {
return OwningObject->getSectionSize(SectionPimpl);
}
inline Expected<StringRef> SectionRef::getContents() const {
Expected<ArrayRef<uint8_t>> Res =
OwningObject->getSectionContents(SectionPimpl);
if (!Res)
return Res.takeError();
return StringRef(reinterpret_cast<const char *>(Res->data()), Res->size());
}
inline Align SectionRef::getAlignment() const {
return MaybeAlign(OwningObject->getSectionAlignment(SectionPimpl))
.valueOrOne();
}
inline bool SectionRef::isCompressed() const {
return OwningObject->isSectionCompressed(SectionPimpl);
}
inline bool SectionRef::isText() const {
return OwningObject->isSectionText(SectionPimpl);
}
inline bool SectionRef::isData() const {
return OwningObject->isSectionData(SectionPimpl);
}
inline bool SectionRef::isBSS() const {
return OwningObject->isSectionBSS(SectionPimpl);
}
inline bool SectionRef::isVirtual() const {
return OwningObject->isSectionVirtual(SectionPimpl);
}
inline bool SectionRef::isBitcode() const {
return OwningObject->isSectionBitcode(SectionPimpl);
}
inline bool SectionRef::isStripped() const {
return OwningObject->isSectionStripped(SectionPimpl);
}
inline bool SectionRef::isBerkeleyText() const {
return OwningObject->isBerkeleyText(SectionPimpl);
}
inline bool SectionRef::isBerkeleyData() const {
return OwningObject->isBerkeleyData(SectionPimpl);
}
inline bool SectionRef::isDebugSection() const {
return OwningObject->isDebugSection(SectionPimpl);
}
inline relocation_iterator SectionRef::relocation_begin() const {
return OwningObject->section_rel_begin(SectionPimpl);
}
inline relocation_iterator SectionRef::relocation_end() const {
return OwningObject->section_rel_end(SectionPimpl);
}
inline Expected<section_iterator> SectionRef::getRelocatedSection() const {
return OwningObject->getRelocatedSection(SectionPimpl);
}
inline DataRefImpl SectionRef::getRawDataRefImpl() const {
return SectionPimpl;
}
inline const ObjectFile *SectionRef::getObject() const {
return OwningObject;
}
/// RelocationRef
inline RelocationRef::RelocationRef(DataRefImpl RelocationP,
const ObjectFile *Owner)
: RelocationPimpl(RelocationP)
, OwningObject(Owner) {}
inline bool RelocationRef::operator==(const RelocationRef &Other) const {
return RelocationPimpl == Other.RelocationPimpl;
}
inline void RelocationRef::moveNext() {
return OwningObject->moveRelocationNext(RelocationPimpl);
}
inline uint64_t RelocationRef::getOffset() const {
return OwningObject->getRelocationOffset(RelocationPimpl);
}
inline symbol_iterator RelocationRef::getSymbol() const {
return OwningObject->getRelocationSymbol(RelocationPimpl);
}
inline uint64_t RelocationRef::getType() const {
return OwningObject->getRelocationType(RelocationPimpl);
}
inline void RelocationRef::getTypeName(SmallVectorImpl<char> &Result) const {
return OwningObject->getRelocationTypeName(RelocationPimpl, Result);
}
inline DataRefImpl RelocationRef::getRawDataRefImpl() const {
return RelocationPimpl;
}
inline const ObjectFile *RelocationRef::getObject() const {
return OwningObject;
}
} // end namespace object
template <> struct DenseMapInfo<object::SectionRef> {
static bool isEqual(const object::SectionRef &A,
const object::SectionRef &B) {
return A == B;
}
static object::SectionRef getEmptyKey() {
return object::SectionRef({}, nullptr);
}
static object::SectionRef getTombstoneKey() {
object::DataRefImpl TS;
TS.p = (uintptr_t)-1;
return object::SectionRef(TS, nullptr);
}
static unsigned getHashValue(const object::SectionRef &Sec) {
object::DataRefImpl Raw = Sec.getRawDataRefImpl();
return hash_combine(Raw.p, Raw.d.a, Raw.d.b);
}
};
} // end namespace llvm
#endif // LLVM_OBJECT_OBJECTFILE_H
|