llvm/tools/yaml2obj/yaml2macho.cpp
Chandler Carruth 6b547686c5 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351636 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-19 08:50:56 +00:00

591 lines
20 KiB
C++

//===- yaml2macho - Convert YAML to a Mach object file --------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
///
/// \file
/// The Mach component of yaml2obj.
///
//===----------------------------------------------------------------------===//
#include "yaml2obj.h"
#include "llvm/BinaryFormat/MachO.h"
#include "llvm/ObjectYAML/DWARFEmitter.h"
#include "llvm/ObjectYAML/ObjectYAML.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/LEB128.h"
#include "llvm/Support/YAMLTraits.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/Format.h"
using namespace llvm;
namespace {
class MachOWriter {
public:
MachOWriter(MachOYAML::Object &Obj) : Obj(Obj), is64Bit(true), fileStart(0) {
is64Bit = Obj.Header.magic == MachO::MH_MAGIC_64 ||
Obj.Header.magic == MachO::MH_CIGAM_64;
memset(reinterpret_cast<void *>(&Header), 0, sizeof(MachO::mach_header_64));
}
Error writeMachO(raw_ostream &OS);
private:
Error writeHeader(raw_ostream &OS);
Error writeLoadCommands(raw_ostream &OS);
Error writeSectionData(raw_ostream &OS);
Error writeLinkEditData(raw_ostream &OS);
void writeBindOpcodes(raw_ostream &OS,
std::vector<MachOYAML::BindOpcode> &BindOpcodes);
// LinkEdit writers
Error writeRebaseOpcodes(raw_ostream &OS);
Error writeBasicBindOpcodes(raw_ostream &OS);
Error writeWeakBindOpcodes(raw_ostream &OS);
Error writeLazyBindOpcodes(raw_ostream &OS);
Error writeNameList(raw_ostream &OS);
Error writeStringTable(raw_ostream &OS);
Error writeExportTrie(raw_ostream &OS);
void dumpExportEntry(raw_ostream &OS, MachOYAML::ExportEntry &Entry);
void ZeroToOffset(raw_ostream &OS, size_t offset);
MachOYAML::Object &Obj;
bool is64Bit;
uint64_t fileStart;
MachO::mach_header_64 Header;
};
Error MachOWriter::writeMachO(raw_ostream &OS) {
fileStart = OS.tell();
if (auto Err = writeHeader(OS))
return Err;
if (auto Err = writeLoadCommands(OS))
return Err;
if (auto Err = writeSectionData(OS))
return Err;
return Error::success();
}
Error MachOWriter::writeHeader(raw_ostream &OS) {
Header.magic = Obj.Header.magic;
Header.cputype = Obj.Header.cputype;
Header.cpusubtype = Obj.Header.cpusubtype;
Header.filetype = Obj.Header.filetype;
Header.ncmds = Obj.Header.ncmds;
Header.sizeofcmds = Obj.Header.sizeofcmds;
Header.flags = Obj.Header.flags;
Header.reserved = Obj.Header.reserved;
if (Obj.IsLittleEndian != sys::IsLittleEndianHost)
MachO::swapStruct(Header);
auto header_size =
is64Bit ? sizeof(MachO::mach_header_64) : sizeof(MachO::mach_header);
OS.write((const char *)&Header, header_size);
return Error::success();
}
template <typename SectionType>
SectionType constructSection(MachOYAML::Section Sec) {
SectionType TempSec;
memcpy(reinterpret_cast<void *>(&TempSec.sectname[0]), &Sec.sectname[0], 16);
memcpy(reinterpret_cast<void *>(&TempSec.segname[0]), &Sec.segname[0], 16);
TempSec.addr = Sec.addr;
TempSec.size = Sec.size;
TempSec.offset = Sec.offset;
TempSec.align = Sec.align;
TempSec.reloff = Sec.reloff;
TempSec.nreloc = Sec.nreloc;
TempSec.flags = Sec.flags;
TempSec.reserved1 = Sec.reserved1;
TempSec.reserved2 = Sec.reserved2;
return TempSec;
}
template <typename StructType>
size_t writeLoadCommandData(MachOYAML::LoadCommand &LC, raw_ostream &OS,
bool IsLittleEndian) {
return 0;
}
template <>
size_t writeLoadCommandData<MachO::segment_command>(MachOYAML::LoadCommand &LC,
raw_ostream &OS,
bool IsLittleEndian) {
size_t BytesWritten = 0;
for (const auto &Sec : LC.Sections) {
auto TempSec = constructSection<MachO::section>(Sec);
if (IsLittleEndian != sys::IsLittleEndianHost)
MachO::swapStruct(TempSec);
OS.write(reinterpret_cast<const char *>(&(TempSec)),
sizeof(MachO::section));
BytesWritten += sizeof(MachO::section);
}
return BytesWritten;
}
template <>
size_t writeLoadCommandData<MachO::segment_command_64>(
MachOYAML::LoadCommand &LC, raw_ostream &OS, bool IsLittleEndian) {
size_t BytesWritten = 0;
for (const auto &Sec : LC.Sections) {
auto TempSec = constructSection<MachO::section_64>(Sec);
TempSec.reserved3 = Sec.reserved3;
if (IsLittleEndian != sys::IsLittleEndianHost)
MachO::swapStruct(TempSec);
OS.write(reinterpret_cast<const char *>(&(TempSec)),
sizeof(MachO::section_64));
BytesWritten += sizeof(MachO::section_64);
}
return BytesWritten;
}
size_t writePayloadString(MachOYAML::LoadCommand &LC, raw_ostream &OS) {
size_t BytesWritten = 0;
if (!LC.PayloadString.empty()) {
OS.write(LC.PayloadString.c_str(), LC.PayloadString.length());
BytesWritten = LC.PayloadString.length();
}
return BytesWritten;
}
template <>
size_t writeLoadCommandData<MachO::dylib_command>(MachOYAML::LoadCommand &LC,
raw_ostream &OS,
bool IsLittleEndian) {
return writePayloadString(LC, OS);
}
template <>
size_t writeLoadCommandData<MachO::dylinker_command>(MachOYAML::LoadCommand &LC,
raw_ostream &OS,
bool IsLittleEndian) {
return writePayloadString(LC, OS);
}
template <>
size_t writeLoadCommandData<MachO::rpath_command>(MachOYAML::LoadCommand &LC,
raw_ostream &OS,
bool IsLittleEndian) {
return writePayloadString(LC, OS);
}
template <>
size_t writeLoadCommandData<MachO::build_version_command>(
MachOYAML::LoadCommand &LC, raw_ostream &OS, bool IsLittleEndian) {
size_t BytesWritten = 0;
for (const auto &T : LC.Tools) {
struct MachO::build_tool_version tool = T;
if (IsLittleEndian != sys::IsLittleEndianHost)
MachO::swapStruct(tool);
OS.write(reinterpret_cast<const char *>(&tool),
sizeof(MachO::build_tool_version));
BytesWritten += sizeof(MachO::build_tool_version);
}
return BytesWritten;
}
void ZeroFillBytes(raw_ostream &OS, size_t Size) {
std::vector<uint8_t> FillData;
FillData.insert(FillData.begin(), Size, 0);
OS.write(reinterpret_cast<char *>(FillData.data()), Size);
}
void Fill(raw_ostream &OS, size_t Size, uint32_t Data) {
std::vector<uint32_t> FillData;
FillData.insert(FillData.begin(), (Size / 4) + 1, Data);
OS.write(reinterpret_cast<char *>(FillData.data()), Size);
}
void MachOWriter::ZeroToOffset(raw_ostream &OS, size_t Offset) {
auto currOffset = OS.tell() - fileStart;
if (currOffset < Offset)
ZeroFillBytes(OS, Offset - currOffset);
}
Error MachOWriter::writeLoadCommands(raw_ostream &OS) {
for (auto &LC : Obj.LoadCommands) {
size_t BytesWritten = 0;
llvm::MachO::macho_load_command Data = LC.Data;
#define HANDLE_LOAD_COMMAND(LCName, LCValue, LCStruct) \
case MachO::LCName: \
if (Obj.IsLittleEndian != sys::IsLittleEndianHost) \
MachO::swapStruct(Data.LCStruct##_data); \
OS.write(reinterpret_cast<const char *>(&(Data.LCStruct##_data)), \
sizeof(MachO::LCStruct)); \
BytesWritten = sizeof(MachO::LCStruct); \
BytesWritten += \
writeLoadCommandData<MachO::LCStruct>(LC, OS, Obj.IsLittleEndian); \
break;
switch (LC.Data.load_command_data.cmd) {
default:
if (Obj.IsLittleEndian != sys::IsLittleEndianHost)
MachO::swapStruct(Data.load_command_data);
OS.write(reinterpret_cast<const char *>(&(Data.load_command_data)),
sizeof(MachO::load_command));
BytesWritten = sizeof(MachO::load_command);
BytesWritten +=
writeLoadCommandData<MachO::load_command>(LC, OS, Obj.IsLittleEndian);
break;
#include "llvm/BinaryFormat/MachO.def"
}
if (LC.PayloadBytes.size() > 0) {
OS.write(reinterpret_cast<const char *>(LC.PayloadBytes.data()),
LC.PayloadBytes.size());
BytesWritten += LC.PayloadBytes.size();
}
if (LC.ZeroPadBytes > 0) {
ZeroFillBytes(OS, LC.ZeroPadBytes);
BytesWritten += LC.ZeroPadBytes;
}
// Fill remaining bytes with 0. This will only get hit in partially
// specified test cases.
auto BytesRemaining = LC.Data.load_command_data.cmdsize - BytesWritten;
if (BytesRemaining > 0) {
ZeroFillBytes(OS, BytesRemaining);
}
}
return Error::success();
}
Error MachOWriter::writeSectionData(raw_ostream &OS) {
bool FoundLinkEditSeg = false;
for (auto &LC : Obj.LoadCommands) {
switch (LC.Data.load_command_data.cmd) {
case MachO::LC_SEGMENT:
case MachO::LC_SEGMENT_64:
uint64_t segOff = is64Bit ? LC.Data.segment_command_64_data.fileoff
: LC.Data.segment_command_data.fileoff;
if (0 == strncmp(&LC.Data.segment_command_data.segname[0], "__LINKEDIT", 16)) {
FoundLinkEditSeg = true;
if (auto Err = writeLinkEditData(OS))
return Err;
}
for (auto &Sec : LC.Sections) {
ZeroToOffset(OS, Sec.offset);
// Zero Fill any data between the end of the last thing we wrote and the
// start of this section.
assert((OS.tell() - fileStart <= Sec.offset ||
Sec.offset == (uint32_t)0) &&
"Wrote too much data somewhere, section offsets don't line up.");
if (0 == strncmp(&Sec.segname[0], "__DWARF", 16)) {
if (0 == strncmp(&Sec.sectname[0], "__debug_str", 16)) {
DWARFYAML::EmitDebugStr(OS, Obj.DWARF);
} else if (0 == strncmp(&Sec.sectname[0], "__debug_abbrev", 16)) {
DWARFYAML::EmitDebugAbbrev(OS, Obj.DWARF);
} else if (0 == strncmp(&Sec.sectname[0], "__debug_aranges", 16)) {
DWARFYAML::EmitDebugAranges(OS, Obj.DWARF);
} else if (0 == strncmp(&Sec.sectname[0], "__debug_pubnames", 16)) {
DWARFYAML::EmitPubSection(OS, Obj.DWARF.PubNames,
Obj.IsLittleEndian);
} else if (0 == strncmp(&Sec.sectname[0], "__debug_pubtypes", 16)) {
DWARFYAML::EmitPubSection(OS, Obj.DWARF.PubTypes,
Obj.IsLittleEndian);
} else if (0 == strncmp(&Sec.sectname[0], "__debug_info", 16)) {
DWARFYAML::EmitDebugInfo(OS, Obj.DWARF);
} else if (0 == strncmp(&Sec.sectname[0], "__debug_line", 16)) {
DWARFYAML::EmitDebugLine(OS, Obj.DWARF);
}
} else {
// Fills section data with 0xDEADBEEF
Fill(OS, Sec.size, 0xDEADBEEFu);
}
}
uint64_t segSize = is64Bit ? LC.Data.segment_command_64_data.filesize
: LC.Data.segment_command_data.filesize;
ZeroToOffset(OS, segOff + segSize);
break;
}
}
// Old PPC Object Files didn't have __LINKEDIT segments, the data was just
// stuck at the end of the file.
if (!FoundLinkEditSeg) {
if (auto Err = writeLinkEditData(OS))
return Err;
}
return Error::success();
}
void MachOWriter::writeBindOpcodes(
raw_ostream &OS, std::vector<MachOYAML::BindOpcode> &BindOpcodes) {
for (auto Opcode : BindOpcodes) {
uint8_t OpByte = Opcode.Opcode | Opcode.Imm;
OS.write(reinterpret_cast<char *>(&OpByte), 1);
for (auto Data : Opcode.ULEBExtraData) {
encodeULEB128(Data, OS);
}
for (auto Data : Opcode.SLEBExtraData) {
encodeSLEB128(Data, OS);
}
if (!Opcode.Symbol.empty()) {
OS.write(Opcode.Symbol.data(), Opcode.Symbol.size());
OS.write('\0');
}
}
}
void MachOWriter::dumpExportEntry(raw_ostream &OS,
MachOYAML::ExportEntry &Entry) {
encodeSLEB128(Entry.TerminalSize, OS);
if (Entry.TerminalSize > 0) {
encodeSLEB128(Entry.Flags, OS);
if (Entry.Flags & MachO::EXPORT_SYMBOL_FLAGS_REEXPORT) {
encodeSLEB128(Entry.Other, OS);
OS << Entry.ImportName;
OS.write('\0');
} else {
encodeSLEB128(Entry.Address, OS);
if (Entry.Flags & MachO::EXPORT_SYMBOL_FLAGS_STUB_AND_RESOLVER)
encodeSLEB128(Entry.Other, OS);
}
}
OS.write(static_cast<uint8_t>(Entry.Children.size()));
for (auto EE : Entry.Children) {
OS << EE.Name;
OS.write('\0');
encodeSLEB128(EE.NodeOffset, OS);
}
for (auto EE : Entry.Children)
dumpExportEntry(OS, EE);
}
Error MachOWriter::writeExportTrie(raw_ostream &OS) {
dumpExportEntry(OS, Obj.LinkEdit.ExportTrie);
return Error::success();
}
template <typename NListType>
void writeNListEntry(MachOYAML::NListEntry &NLE, raw_ostream &OS,
bool IsLittleEndian) {
NListType ListEntry;
ListEntry.n_strx = NLE.n_strx;
ListEntry.n_type = NLE.n_type;
ListEntry.n_sect = NLE.n_sect;
ListEntry.n_desc = NLE.n_desc;
ListEntry.n_value = NLE.n_value;
if (IsLittleEndian != sys::IsLittleEndianHost)
MachO::swapStruct(ListEntry);
OS.write(reinterpret_cast<const char *>(&ListEntry), sizeof(NListType));
}
Error MachOWriter::writeLinkEditData(raw_ostream &OS) {
typedef Error (MachOWriter::*writeHandler)(raw_ostream &);
typedef std::pair<uint64_t, writeHandler> writeOperation;
std::vector<writeOperation> WriteQueue;
MachO::dyld_info_command *DyldInfoOnlyCmd = 0;
MachO::symtab_command *SymtabCmd = 0;
for (auto &LC : Obj.LoadCommands) {
switch (LC.Data.load_command_data.cmd) {
case MachO::LC_SYMTAB:
SymtabCmd = &LC.Data.symtab_command_data;
WriteQueue.push_back(
std::make_pair(SymtabCmd->symoff, &MachOWriter::writeNameList));
WriteQueue.push_back(
std::make_pair(SymtabCmd->stroff, &MachOWriter::writeStringTable));
break;
case MachO::LC_DYLD_INFO_ONLY:
DyldInfoOnlyCmd = &LC.Data.dyld_info_command_data;
WriteQueue.push_back(std::make_pair(DyldInfoOnlyCmd->rebase_off,
&MachOWriter::writeRebaseOpcodes));
WriteQueue.push_back(std::make_pair(DyldInfoOnlyCmd->bind_off,
&MachOWriter::writeBasicBindOpcodes));
WriteQueue.push_back(std::make_pair(DyldInfoOnlyCmd->weak_bind_off,
&MachOWriter::writeWeakBindOpcodes));
WriteQueue.push_back(std::make_pair(DyldInfoOnlyCmd->lazy_bind_off,
&MachOWriter::writeLazyBindOpcodes));
WriteQueue.push_back(std::make_pair(DyldInfoOnlyCmd->export_off,
&MachOWriter::writeExportTrie));
break;
}
}
llvm::sort(WriteQueue, [](const writeOperation &a, const writeOperation &b) {
return a.first < b.first;
});
for (auto writeOp : WriteQueue) {
ZeroToOffset(OS, writeOp.first);
if (auto Err = (this->*writeOp.second)(OS))
return Err;
}
return Error::success();
}
Error MachOWriter::writeRebaseOpcodes(raw_ostream &OS) {
MachOYAML::LinkEditData &LinkEdit = Obj.LinkEdit;
for (auto Opcode : LinkEdit.RebaseOpcodes) {
uint8_t OpByte = Opcode.Opcode | Opcode.Imm;
OS.write(reinterpret_cast<char *>(&OpByte), 1);
for (auto Data : Opcode.ExtraData) {
encodeULEB128(Data, OS);
}
}
return Error::success();
}
Error MachOWriter::writeBasicBindOpcodes(raw_ostream &OS) {
writeBindOpcodes(OS, Obj.LinkEdit.BindOpcodes);
return Error::success();
}
Error MachOWriter::writeWeakBindOpcodes(raw_ostream &OS) {
writeBindOpcodes(OS, Obj.LinkEdit.WeakBindOpcodes);
return Error::success();
}
Error MachOWriter::writeLazyBindOpcodes(raw_ostream &OS) {
writeBindOpcodes(OS, Obj.LinkEdit.LazyBindOpcodes);
return Error::success();
}
Error MachOWriter::writeNameList(raw_ostream &OS) {
for (auto NLE : Obj.LinkEdit.NameList) {
if (is64Bit)
writeNListEntry<MachO::nlist_64>(NLE, OS, Obj.IsLittleEndian);
else
writeNListEntry<MachO::nlist>(NLE, OS, Obj.IsLittleEndian);
}
return Error::success();
}
Error MachOWriter::writeStringTable(raw_ostream &OS) {
for (auto Str : Obj.LinkEdit.StringTable) {
OS.write(Str.data(), Str.size());
OS.write('\0');
}
return Error::success();
}
class UniversalWriter {
public:
UniversalWriter(yaml::YamlObjectFile &ObjectFile)
: ObjectFile(ObjectFile), fileStart(0) {}
Error writeMachO(raw_ostream &OS);
private:
Error writeFatHeader(raw_ostream &OS);
Error writeFatArchs(raw_ostream &OS);
void ZeroToOffset(raw_ostream &OS, size_t offset);
yaml::YamlObjectFile &ObjectFile;
uint64_t fileStart;
};
Error UniversalWriter::writeMachO(raw_ostream &OS) {
fileStart = OS.tell();
if (ObjectFile.MachO) {
MachOWriter Writer(*ObjectFile.MachO);
return Writer.writeMachO(OS);
}
if (auto Err = writeFatHeader(OS))
return Err;
if (auto Err = writeFatArchs(OS))
return Err;
auto &FatFile = *ObjectFile.FatMachO;
assert(FatFile.FatArchs.size() == FatFile.Slices.size());
for (size_t i = 0; i < FatFile.Slices.size(); i++) {
ZeroToOffset(OS, FatFile.FatArchs[i].offset);
MachOWriter Writer(FatFile.Slices[i]);
if (auto Err = Writer.writeMachO(OS))
return Err;
auto SliceEnd = FatFile.FatArchs[i].offset + FatFile.FatArchs[i].size;
ZeroToOffset(OS, SliceEnd);
}
return Error::success();
}
Error UniversalWriter::writeFatHeader(raw_ostream &OS) {
auto &FatFile = *ObjectFile.FatMachO;
MachO::fat_header header;
header.magic = FatFile.Header.magic;
header.nfat_arch = FatFile.Header.nfat_arch;
if (sys::IsLittleEndianHost)
swapStruct(header);
OS.write(reinterpret_cast<const char *>(&header), sizeof(MachO::fat_header));
return Error::success();
}
template <typename FatArchType>
FatArchType constructFatArch(MachOYAML::FatArch &Arch) {
FatArchType FatArch;
FatArch.cputype = Arch.cputype;
FatArch.cpusubtype = Arch.cpusubtype;
FatArch.offset = Arch.offset;
FatArch.size = Arch.size;
FatArch.align = Arch.align;
return FatArch;
}
template <typename StructType>
void writeFatArch(MachOYAML::FatArch &LC, raw_ostream &OS) {}
template <>
void writeFatArch<MachO::fat_arch>(MachOYAML::FatArch &Arch, raw_ostream &OS) {
auto FatArch = constructFatArch<MachO::fat_arch>(Arch);
if (sys::IsLittleEndianHost)
swapStruct(FatArch);
OS.write(reinterpret_cast<const char *>(&FatArch), sizeof(MachO::fat_arch));
}
template <>
void writeFatArch<MachO::fat_arch_64>(MachOYAML::FatArch &Arch,
raw_ostream &OS) {
auto FatArch = constructFatArch<MachO::fat_arch_64>(Arch);
FatArch.reserved = Arch.reserved;
if (sys::IsLittleEndianHost)
swapStruct(FatArch);
OS.write(reinterpret_cast<const char *>(&FatArch),
sizeof(MachO::fat_arch_64));
}
Error UniversalWriter::writeFatArchs(raw_ostream &OS) {
auto &FatFile = *ObjectFile.FatMachO;
bool is64Bit = FatFile.Header.magic == MachO::FAT_MAGIC_64;
for (auto Arch : FatFile.FatArchs) {
if (is64Bit)
writeFatArch<MachO::fat_arch_64>(Arch, OS);
else
writeFatArch<MachO::fat_arch>(Arch, OS);
}
return Error::success();
}
void UniversalWriter::ZeroToOffset(raw_ostream &OS, size_t Offset) {
auto currOffset = OS.tell() - fileStart;
if (currOffset < Offset)
ZeroFillBytes(OS, Offset - currOffset);
}
} // end anonymous namespace
int yaml2macho(yaml::YamlObjectFile &Doc, raw_ostream &Out) {
UniversalWriter Writer(Doc);
if (auto Err = Writer.writeMachO(Out)) {
errs() << toString(std::move(Err));
return 1;
}
return 0;
}