llvm-project/lld/MachO/InputFiles.h

122 lines
3.7 KiB
C++

//===- InputFiles.h ---------------------------------------------*- 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
//
//===----------------------------------------------------------------------===//
#ifndef LLD_MACHO_INPUT_FILES_H
#define LLD_MACHO_INPUT_FILES_H
#include "MachOStructs.h"
#include "lld/Common/LLVM.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/BinaryFormat/MachO.h"
#include "llvm/Object/Archive.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/TextAPI/MachO/InterfaceFile.h"
#include "llvm/TextAPI/MachO/TextAPIReader.h"
#include <map>
#include <vector>
namespace lld {
namespace macho {
class InputSection;
class Symbol;
struct Reloc;
// If .subsections_via_symbols is set, each InputSection will be split along
// symbol boundaries. The keys of a SubsectionMap represent the offsets of
// each subsection from the start of the original pre-split InputSection.
using SubsectionMap = std::map<uint32_t, InputSection *>;
class InputFile {
public:
enum Kind {
ObjKind,
DylibKind,
ArchiveKind,
};
virtual ~InputFile() = default;
Kind kind() const { return fileKind; }
StringRef getName() const { return mb.getBufferIdentifier(); }
MemoryBufferRef mb;
std::vector<Symbol *> symbols;
ArrayRef<llvm::MachO::section_64> sectionHeaders;
std::vector<SubsectionMap> subsections;
protected:
InputFile(Kind kind, MemoryBufferRef mb) : mb(mb), fileKind(kind) {}
void parseSections(ArrayRef<llvm::MachO::section_64>);
void parseSymbols(ArrayRef<lld::structs::nlist_64> nList, const char *strtab,
bool subsectionsViaSymbols);
void parseRelocations(const llvm::MachO::section_64 &, SubsectionMap &);
private:
const Kind fileKind;
};
// .o file
class ObjFile : public InputFile {
public:
explicit ObjFile(MemoryBufferRef mb);
static bool classof(const InputFile *f) { return f->kind() == ObjKind; }
};
// .dylib file
class DylibFile : public InputFile {
public:
explicit DylibFile(std::shared_ptr<llvm::MachO::InterfaceFile> interface,
DylibFile *umbrella = nullptr);
// Mach-O dylibs can re-export other dylibs as sub-libraries, meaning that the
// symbols in those sub-libraries will be available under the umbrella
// library's namespace. Those sub-libraries can also have their own
// re-exports. When loading a re-exported dylib, `umbrella` should be set to
// the root dylib to ensure symbols in the child library are correctly bound
// to the root. On the other hand, if a dylib is being directly loaded
// (through an -lfoo flag), then `umbrella` should be a nullptr.
explicit DylibFile(MemoryBufferRef mb, DylibFile *umbrella = nullptr);
static bool classof(const InputFile *f) { return f->kind() == DylibKind; }
StringRef dylibName;
uint64_t ordinal = 0; // Ordinal numbering starts from 1, so 0 is a sentinel
bool reexport = false;
std::vector<DylibFile *> reexported;
};
// .a file
class ArchiveFile : public InputFile {
public:
explicit ArchiveFile(std::unique_ptr<llvm::object::Archive> &&file);
static bool classof(const InputFile *f) { return f->kind() == ArchiveKind; }
void fetch(const llvm::object::Archive::Symbol &sym);
private:
std::unique_ptr<llvm::object::Archive> file;
// Keep track of children fetched from the archive by tracking
// which address offsets have been fetched already.
llvm::DenseSet<uint64_t> seen;
};
extern std::vector<InputFile *> inputFiles;
llvm::Optional<MemoryBufferRef> readFile(StringRef path);
} // namespace macho
std::string toString(const macho::InputFile *file);
} // namespace lld
#endif