[llvm] r369298 - Recommit "[llvm-objcopy][MachO] Support load commands used in executables/shared libraries"
Seiya Nuta via llvm-commits
llvm-commits at lists.llvm.org
Mon Aug 19 14:05:31 PDT 2019
Author: seiya
Date: Mon Aug 19 14:05:31 2019
New Revision: 369298
URL: http://llvm.org/viewvc/llvm-project?rev=369298&view=rev
Log:
Recommit "[llvm-objcopy][MachO] Support load commands used in executables/shared libraries"
Summary:
This patch implements copying some load commands that appear in executables/shared libraries such as the indirect symbol table.
I don't add tests intentionally because this patch is incomplete: we need a layout algorithm for executables/shared libraries. I'll submit it as a separate patch with tests.
Reviewers: alexshap, rupprecht, jhenderson, compnerd
Reviewed By: alexshap
Subscribers: abrachet, mgorny, mgrang, MaskRay, mtrent, jakehehrlich, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63395
Added:
llvm/trunk/tools/llvm-objcopy/MachO/MachOLayoutBuilder.cpp
llvm/trunk/tools/llvm-objcopy/MachO/MachOLayoutBuilder.h
Modified:
llvm/trunk/tools/llvm-objcopy/CMakeLists.txt
llvm/trunk/tools/llvm-objcopy/MachO/MachOObjcopy.cpp
llvm/trunk/tools/llvm-objcopy/MachO/MachOReader.cpp
llvm/trunk/tools/llvm-objcopy/MachO/MachOReader.h
llvm/trunk/tools/llvm-objcopy/MachO/MachOWriter.cpp
llvm/trunk/tools/llvm-objcopy/MachO/MachOWriter.h
llvm/trunk/tools/llvm-objcopy/MachO/Object.h
Modified: llvm/trunk/tools/llvm-objcopy/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objcopy/CMakeLists.txt?rev=369298&r1=369297&r2=369298&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-objcopy/CMakeLists.txt (original)
+++ llvm/trunk/tools/llvm-objcopy/CMakeLists.txt Mon Aug 19 14:05:31 2019
@@ -26,6 +26,7 @@ add_llvm_tool(llvm-objcopy
MachO/MachOObjcopy.cpp
MachO/MachOReader.cpp
MachO/MachOWriter.cpp
+ MachO/MachOLayoutBuilder.cpp
MachO/Object.cpp
DEPENDS
ObjcopyOptsTableGen
Added: llvm/trunk/tools/llvm-objcopy/MachO/MachOLayoutBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objcopy/MachO/MachOLayoutBuilder.cpp?rev=369298&view=auto
==============================================================================
--- llvm/trunk/tools/llvm-objcopy/MachO/MachOLayoutBuilder.cpp (added)
+++ llvm/trunk/tools/llvm-objcopy/MachO/MachOLayoutBuilder.cpp Mon Aug 19 14:05:31 2019
@@ -0,0 +1,322 @@
+//===- MachOLayoutBuilder.cpp -----------------------------------*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "MachOLayoutBuilder.h"
+#include "llvm/Support/Errc.h"
+#include "llvm/Support/ErrorHandling.h"
+
+namespace llvm {
+namespace objcopy {
+namespace macho {
+
+uint32_t MachOLayoutBuilder::computeSizeOfCmds() const {
+ uint32_t Size = 0;
+ for (const auto &LC : O.LoadCommands) {
+ auto &MLC = LC.MachOLoadCommand;
+ auto cmd = MLC.load_command_data.cmd;
+ switch (cmd) {
+ case MachO::LC_SEGMENT:
+ Size += sizeof(MachO::segment_command) +
+ sizeof(MachO::section) * LC.Sections.size();
+ continue;
+ case MachO::LC_SEGMENT_64:
+ Size += sizeof(MachO::segment_command_64) +
+ sizeof(MachO::section_64) * LC.Sections.size();
+ continue;
+ }
+
+ switch (cmd) {
+#define HANDLE_LOAD_COMMAND(LCName, LCValue, LCStruct) \
+ case MachO::LCName: \
+ Size += sizeof(MachO::LCStruct) + LC.Payload.size(); \
+ break;
+#include "llvm/BinaryFormat/MachO.def"
+#undef HANDLE_LOAD_COMMAND
+ }
+ }
+
+ return Size;
+}
+
+void MachOLayoutBuilder::constructStringTable() {
+ for (std::unique_ptr<SymbolEntry> &Sym : O.SymTable.Symbols)
+ StrTableBuilder.add(Sym->Name);
+ StrTableBuilder.finalize();
+}
+
+void MachOLayoutBuilder::updateSymbolIndexes() {
+ uint32_t Index = 0;
+ for (auto &Symbol : O.SymTable.Symbols)
+ Symbol->Index = Index++;
+}
+
+// Updates the index and the number of local/external/undefined symbols.
+void MachOLayoutBuilder::updateDySymTab(MachO::macho_load_command &MLC) {
+ assert(MLC.load_command_data.cmd == MachO::LC_DYSYMTAB);
+ // Make sure that nlist entries in the symbol table are sorted by the those
+ // types. The order is: local < defined external < undefined external.
+ assert(std::is_sorted(O.SymTable.Symbols.begin(), O.SymTable.Symbols.end(),
+ [](const std::unique_ptr<SymbolEntry> &A,
+ const std::unique_ptr<SymbolEntry> &B) {
+ return (A->isLocalSymbol() && !B->isLocalSymbol()) ||
+ (!A->isUndefinedSymbol() &&
+ B->isUndefinedSymbol());
+ }) &&
+ "Symbols are not sorted by their types.");
+
+ uint32_t NumLocalSymbols = 0;
+ auto Iter = O.SymTable.Symbols.begin();
+ auto End = O.SymTable.Symbols.end();
+ for (; Iter != End; ++Iter) {
+ if ((*Iter)->isExternalSymbol())
+ break;
+
+ ++NumLocalSymbols;
+ }
+
+ uint32_t NumExtDefSymbols = 0;
+ for (; Iter != End; ++Iter) {
+ if ((*Iter)->isUndefinedSymbol())
+ break;
+
+ ++NumExtDefSymbols;
+ }
+
+ MLC.dysymtab_command_data.ilocalsym = 0;
+ MLC.dysymtab_command_data.nlocalsym = NumLocalSymbols;
+ MLC.dysymtab_command_data.iextdefsym = NumLocalSymbols;
+ MLC.dysymtab_command_data.nextdefsym = NumExtDefSymbols;
+ MLC.dysymtab_command_data.iundefsym = NumLocalSymbols + NumExtDefSymbols;
+ MLC.dysymtab_command_data.nundefsym =
+ O.SymTable.Symbols.size() - (NumLocalSymbols + NumExtDefSymbols);
+}
+
+// Recomputes and updates offset and size fields in load commands and sections
+// since they could be modified.
+uint64_t MachOLayoutBuilder::layoutSegments() {
+ auto HeaderSize =
+ Is64Bit ? sizeof(MachO::mach_header_64) : sizeof(MachO::mach_header);
+ auto Offset = HeaderSize + O.Header.SizeOfCmds;
+
+ // Lay out sections.
+ for (auto &LC : O.LoadCommands) {
+ uint64_t FileOff = Offset;
+ auto &MLC = LC.MachOLoadCommand;
+ StringRef Segname;
+ switch (MLC.load_command_data.cmd) {
+ case MachO::LC_SEGMENT:
+ Segname = StringRef(MLC.segment_command_data.segname,
+ strnlen(MLC.segment_command_data.segname,
+ sizeof(MLC.segment_command_data.segname)));
+ break;
+ case MachO::LC_SEGMENT_64:
+ Segname = StringRef(MLC.segment_command_64_data.segname,
+ strnlen(MLC.segment_command_64_data.segname,
+ sizeof(MLC.segment_command_64_data.segname)));
+ break;
+ default:
+ continue;
+ }
+
+ if (Segname == "__LINKEDIT") {
+ // We update the __LINKEDIT segment later (in layoutTail).
+ assert(LC.Sections.empty() && "__LINKEDIT segment has sections");
+ LinkEditLoadCommand = &MLC;
+ continue;
+ }
+
+ // Update file offsets and sizes of sections.
+ uint64_t VMSize = 0;
+ uint64_t FileOffsetInSegment = 0;
+ for (auto &Sec : LC.Sections) {
+ if (!Sec.isVirtualSection()) {
+ auto FilePaddingSize =
+ OffsetToAlignment(FileOffsetInSegment, 1ull << Sec.Align);
+ Sec.Offset = Offset + FileOffsetInSegment + FilePaddingSize;
+ Sec.Size = Sec.Content.size();
+ FileOffsetInSegment += FilePaddingSize + Sec.Size;
+ }
+
+ VMSize = std::max(VMSize, Sec.Addr + Sec.Size);
+ }
+
+ // TODO: Handle the __PAGEZERO segment.
+ switch (MLC.load_command_data.cmd) {
+ case MachO::LC_SEGMENT:
+ MLC.segment_command_data.cmdsize =
+ sizeof(MachO::segment_command) +
+ sizeof(MachO::section) * LC.Sections.size();
+ MLC.segment_command_data.nsects = LC.Sections.size();
+ MLC.segment_command_data.fileoff = FileOff;
+ MLC.segment_command_data.vmsize = VMSize;
+ MLC.segment_command_data.filesize = FileOffsetInSegment;
+ break;
+ case MachO::LC_SEGMENT_64:
+ MLC.segment_command_64_data.cmdsize =
+ sizeof(MachO::segment_command_64) +
+ sizeof(MachO::section_64) * LC.Sections.size();
+ MLC.segment_command_64_data.nsects = LC.Sections.size();
+ MLC.segment_command_64_data.fileoff = FileOff;
+ MLC.segment_command_64_data.vmsize = VMSize;
+ MLC.segment_command_64_data.filesize = FileOffsetInSegment;
+ break;
+ }
+
+ Offset += FileOffsetInSegment;
+ }
+
+ return Offset;
+}
+
+uint64_t MachOLayoutBuilder::layoutRelocations(uint64_t Offset) {
+ for (auto &LC : O.LoadCommands)
+ for (auto &Sec : LC.Sections) {
+ Sec.RelOff = Sec.Relocations.empty() ? 0 : Offset;
+ Sec.NReloc = Sec.Relocations.size();
+ Offset += sizeof(MachO::any_relocation_info) * Sec.NReloc;
+ }
+
+ return Offset;
+}
+
+Error MachOLayoutBuilder::layoutTail(uint64_t Offset) {
+ // The order of LINKEDIT elements is as follows:
+ // rebase info, binding info, weak binding info, lazy binding info, export
+ // trie, data-in-code, symbol table, indirect symbol table, symbol table
+ // strings.
+ uint64_t NListSize = Is64Bit ? sizeof(MachO::nlist_64) : sizeof(MachO::nlist);
+ uint64_t StartOfLinkEdit = Offset;
+ uint64_t StartOfRebaseInfo = StartOfLinkEdit;
+ uint64_t StartOfBindingInfo = StartOfRebaseInfo + O.Rebases.Opcodes.size();
+ uint64_t StartOfWeakBindingInfo = StartOfBindingInfo + O.Binds.Opcodes.size();
+ uint64_t StartOfLazyBindingInfo =
+ StartOfWeakBindingInfo + O.WeakBinds.Opcodes.size();
+ uint64_t StartOfExportTrie =
+ StartOfLazyBindingInfo + O.LazyBinds.Opcodes.size();
+ uint64_t StartOfFunctionStarts = StartOfExportTrie + O.Exports.Trie.size();
+ uint64_t StartOfDataInCode =
+ StartOfFunctionStarts + O.FunctionStarts.Data.size();
+ uint64_t StartOfSymbols = StartOfDataInCode + O.DataInCode.Data.size();
+ uint64_t StartOfIndirectSymbols =
+ StartOfSymbols + NListSize * O.SymTable.Symbols.size();
+ uint64_t StartOfSymbolStrings =
+ StartOfIndirectSymbols +
+ sizeof(uint32_t) * O.IndirectSymTable.Symbols.size();
+ uint64_t LinkEditSize =
+ (StartOfSymbolStrings + StrTableBuilder.getSize()) - StartOfLinkEdit;
+
+ // Now we have determined the layout of the contents of the __LINKEDIT
+ // segment. Update its load command.
+ if (LinkEditLoadCommand) {
+ MachO::macho_load_command *MLC = LinkEditLoadCommand;
+ switch (LinkEditLoadCommand->load_command_data.cmd) {
+ case MachO::LC_SEGMENT:
+ MLC->segment_command_data.cmdsize = sizeof(MachO::segment_command);
+ MLC->segment_command_data.fileoff = StartOfLinkEdit;
+ MLC->segment_command_data.vmsize = alignTo(LinkEditSize, PageSize);
+ MLC->segment_command_data.filesize = LinkEditSize;
+ break;
+ case MachO::LC_SEGMENT_64:
+ MLC->segment_command_64_data.cmdsize = sizeof(MachO::segment_command_64);
+ MLC->segment_command_64_data.fileoff = StartOfLinkEdit;
+ MLC->segment_command_64_data.vmsize = alignTo(LinkEditSize, PageSize);
+ MLC->segment_command_64_data.filesize = LinkEditSize;
+ break;
+ }
+ }
+
+ for (auto &LC : O.LoadCommands) {
+ auto &MLC = LC.MachOLoadCommand;
+ auto cmd = MLC.load_command_data.cmd;
+ switch (cmd) {
+ case MachO::LC_SYMTAB:
+ MLC.symtab_command_data.symoff = StartOfSymbols;
+ MLC.symtab_command_data.nsyms = O.SymTable.Symbols.size();
+ MLC.symtab_command_data.stroff = StartOfSymbolStrings;
+ MLC.symtab_command_data.strsize = StrTableBuilder.getSize();
+ break;
+ case MachO::LC_DYSYMTAB: {
+ if (MLC.dysymtab_command_data.ntoc != 0 ||
+ MLC.dysymtab_command_data.nmodtab != 0 ||
+ MLC.dysymtab_command_data.nextrefsyms != 0 ||
+ MLC.dysymtab_command_data.nlocrel != 0 ||
+ MLC.dysymtab_command_data.nextrel != 0)
+ return createStringError(llvm::errc::not_supported,
+ "shared library is not yet supported");
+
+ if (!O.IndirectSymTable.Symbols.empty()) {
+ MLC.dysymtab_command_data.indirectsymoff = StartOfIndirectSymbols;
+ MLC.dysymtab_command_data.nindirectsyms =
+ O.IndirectSymTable.Symbols.size();
+ }
+
+ updateDySymTab(MLC);
+ break;
+ }
+ case MachO::LC_DATA_IN_CODE:
+ MLC.linkedit_data_command_data.dataoff = StartOfDataInCode;
+ MLC.linkedit_data_command_data.datasize = O.DataInCode.Data.size();
+ break;
+ case MachO::LC_FUNCTION_STARTS:
+ MLC.linkedit_data_command_data.dataoff = StartOfFunctionStarts;
+ MLC.linkedit_data_command_data.datasize = O.FunctionStarts.Data.size();
+ break;
+ case MachO::LC_DYLD_INFO:
+ case MachO::LC_DYLD_INFO_ONLY:
+ MLC.dyld_info_command_data.rebase_off =
+ O.Rebases.Opcodes.empty() ? 0 : StartOfRebaseInfo;
+ MLC.dyld_info_command_data.rebase_size = O.Rebases.Opcodes.size();
+ MLC.dyld_info_command_data.bind_off =
+ O.Binds.Opcodes.empty() ? 0 : StartOfBindingInfo;
+ MLC.dyld_info_command_data.bind_size = O.Binds.Opcodes.size();
+ MLC.dyld_info_command_data.weak_bind_off =
+ O.WeakBinds.Opcodes.empty() ? 0 : StartOfWeakBindingInfo;
+ MLC.dyld_info_command_data.weak_bind_size = O.WeakBinds.Opcodes.size();
+ MLC.dyld_info_command_data.lazy_bind_off =
+ O.LazyBinds.Opcodes.empty() ? 0 : StartOfLazyBindingInfo;
+ MLC.dyld_info_command_data.lazy_bind_size = O.LazyBinds.Opcodes.size();
+ MLC.dyld_info_command_data.export_off =
+ O.Exports.Trie.empty() ? 0 : StartOfExportTrie;
+ MLC.dyld_info_command_data.export_size = O.Exports.Trie.size();
+ break;
+ case MachO::LC_LOAD_DYLINKER:
+ case MachO::LC_MAIN:
+ case MachO::LC_RPATH:
+ case MachO::LC_SEGMENT:
+ case MachO::LC_SEGMENT_64:
+ case MachO::LC_VERSION_MIN_MACOSX:
+ case MachO::LC_BUILD_VERSION:
+ case MachO::LC_ID_DYLIB:
+ case MachO::LC_LOAD_DYLIB:
+ case MachO::LC_UUID:
+ case MachO::LC_SOURCE_VERSION:
+ // Nothing to update.
+ break;
+ default:
+ // Abort if it's unsupported in order to prevent corrupting the object.
+ return createStringError(llvm::errc::not_supported,
+ "unsupported load command (cmd=0x%x)", cmd);
+ }
+ }
+
+ return Error::success();
+}
+
+Error MachOLayoutBuilder::layout() {
+ O.Header.NCmds = O.LoadCommands.size();
+ O.Header.SizeOfCmds = computeSizeOfCmds();
+ constructStringTable();
+ updateSymbolIndexes();
+ uint64_t Offset = layoutSegments();
+ Offset = layoutRelocations(Offset);
+ return layoutTail(Offset);
+}
+
+} // end namespace macho
+} // end namespace objcopy
+} // end namespace llvm
Added: llvm/trunk/tools/llvm-objcopy/MachO/MachOLayoutBuilder.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objcopy/MachO/MachOLayoutBuilder.h?rev=369298&view=auto
==============================================================================
--- llvm/trunk/tools/llvm-objcopy/MachO/MachOLayoutBuilder.h (added)
+++ llvm/trunk/tools/llvm-objcopy/MachO/MachOLayoutBuilder.h Mon Aug 19 14:05:31 2019
@@ -0,0 +1,50 @@
+//===- MachOLayoutBuilder.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 LLVM_OBJCOPY_MACHO_MACHOLAYOUTBUILDER_H
+#define LLVM_OBJCOPY_MACHO_MACHOLAYOUTBUILDER_H
+
+#include "MachOObjcopy.h"
+#include "Object.h"
+
+namespace llvm {
+namespace objcopy {
+namespace macho {
+
+class MachOLayoutBuilder {
+ Object &O;
+ bool Is64Bit;
+ uint64_t PageSize;
+
+ // Points to the __LINKEDIT segment if it exists.
+ MachO::macho_load_command *LinkEditLoadCommand = nullptr;
+ StringTableBuilder StrTableBuilder{StringTableBuilder::MachO};
+
+ uint32_t computeSizeOfCmds() const;
+ void constructStringTable();
+ void updateSymbolIndexes();
+ void updateDySymTab(MachO::macho_load_command &MLC);
+ uint64_t layoutSegments();
+ uint64_t layoutRelocations(uint64_t Offset);
+ Error layoutTail(uint64_t Offset);
+
+public:
+ MachOLayoutBuilder(Object &O, bool Is64Bit, uint64_t PageSize)
+ : O(O), Is64Bit(Is64Bit), PageSize(PageSize) {}
+
+ // Recomputes and updates fields in the given object such as file offsets.
+ Error layout();
+
+ StringTableBuilder &getStringTableBuilder() { return StrTableBuilder; }
+};
+
+} // end namespace macho
+} // end namespace objcopy
+} // end namespace llvm
+
+#endif // LLVM_OBJCOPY_MACHO_MACHOLAYOUTBUILDER_H
Modified: llvm/trunk/tools/llvm-objcopy/MachO/MachOObjcopy.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objcopy/MachO/MachOObjcopy.cpp?rev=369298&r1=369297&r2=369298&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-objcopy/MachO/MachOObjcopy.cpp (original)
+++ llvm/trunk/tools/llvm-objcopy/MachO/MachOObjcopy.cpp Mon Aug 19 14:05:31 2019
@@ -57,7 +57,11 @@ Error executeObjcopyOnBinary(const CopyC
if (Error E = handleArgs(Config, *O))
return createFileError(Config.InputFilename, std::move(E));
- MachOWriter Writer(*O, In.is64Bit(), In.isLittleEndian(), Out);
+ // TODO: Support 16KB pages which are employed in iOS arm64 binaries:
+ // https://github.com/llvm/llvm-project/commit/1bebb2832ee312d3b0316dacff457a7a29435edb
+ const uint64_t PageSize = 4096;
+
+ MachOWriter Writer(*O, In.is64Bit(), In.isLittleEndian(), PageSize, Out);
if (auto E = Writer.finalize())
return E;
return Writer.write();
Modified: llvm/trunk/tools/llvm-objcopy/MachO/MachOReader.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objcopy/MachO/MachOReader.cpp?rev=369298&r1=369297&r2=369298&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-objcopy/MachO/MachOReader.cpp (original)
+++ llvm/trunk/tools/llvm-objcopy/MachO/MachOReader.cpp Mon Aug 19 14:05:31 2019
@@ -129,10 +129,19 @@ void MachOReader::readLoadCommands(Objec
case MachO::LC_SYMTAB:
O.SymTabCommandIndex = O.LoadCommands.size();
break;
+ case MachO::LC_DYSYMTAB:
+ O.DySymTabCommandIndex = O.LoadCommands.size();
+ break;
case MachO::LC_DYLD_INFO:
case MachO::LC_DYLD_INFO_ONLY:
O.DyLdInfoCommandIndex = O.LoadCommands.size();
break;
+ case MachO::LC_DATA_IN_CODE:
+ O.DataInCodeCommandIndex = O.LoadCommands.size();
+ break;
+ case MachO::LC_FUNCTION_STARTS:
+ O.FunctionStartsCommandIndex = O.LoadCommands.size();
+ break;
}
#define HANDLE_LOAD_COMMAND(LCName, LCValue, LCStruct) \
case MachO::LCName: \
@@ -222,6 +231,35 @@ void MachOReader::readExportInfo(Object
O.Exports.Trie = MachOObj.getDyldInfoExportsTrie();
}
+void MachOReader::readDataInCodeData(Object &O) const {
+ if (!O.DataInCodeCommandIndex)
+ return;
+ const MachO::linkedit_data_command &LDC =
+ O.LoadCommands[*O.DataInCodeCommandIndex]
+ .MachOLoadCommand.linkedit_data_command_data;
+
+ O.DataInCode.Data = arrayRefFromStringRef(
+ MachOObj.getData().substr(LDC.dataoff, LDC.datasize));
+}
+
+void MachOReader::readFunctionStartsData(Object &O) const {
+ if (!O.FunctionStartsCommandIndex)
+ return;
+ const MachO::linkedit_data_command &LDC =
+ O.LoadCommands[*O.FunctionStartsCommandIndex]
+ .MachOLoadCommand.linkedit_data_command_data;
+
+ O.FunctionStarts.Data = arrayRefFromStringRef(
+ MachOObj.getData().substr(LDC.dataoff, LDC.datasize));
+}
+
+void MachOReader::readIndirectSymbolTable(Object &O) const {
+ MachO::dysymtab_command DySymTab = MachOObj.getDysymtabLoadCommand();
+ for (uint32_t i = 0; i < DySymTab.nindirectsyms; ++i)
+ O.IndirectSymTable.Symbols.push_back(
+ MachOObj.getIndirectSymbolTableEntry(DySymTab, i));
+}
+
std::unique_ptr<Object> MachOReader::create() const {
auto Obj = std::make_unique<Object>();
readHeader(*Obj);
@@ -233,6 +271,9 @@ std::unique_ptr<Object> MachOReader::cre
readWeakBindInfo(*Obj);
readLazyBindInfo(*Obj);
readExportInfo(*Obj);
+ readDataInCodeData(*Obj);
+ readFunctionStartsData(*Obj);
+ readIndirectSymbolTable(*Obj);
return Obj;
}
Modified: llvm/trunk/tools/llvm-objcopy/MachO/MachOReader.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objcopy/MachO/MachOReader.h?rev=369298&r1=369297&r2=369298&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-objcopy/MachO/MachOReader.h (original)
+++ llvm/trunk/tools/llvm-objcopy/MachO/MachOReader.h Mon Aug 19 14:05:31 2019
@@ -36,6 +36,9 @@ class MachOReader : public Reader {
void readWeakBindInfo(Object &O) const;
void readLazyBindInfo(Object &O) const;
void readExportInfo(Object &O) const;
+ void readDataInCodeData(Object &O) const;
+ void readFunctionStartsData(Object &O) const;
+ void readIndirectSymbolTable(Object &O) const;
public:
explicit MachOReader(const object::MachOObjectFile &Obj) : MachOObj(Obj) {}
Modified: llvm/trunk/tools/llvm-objcopy/MachO/MachOWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objcopy/MachO/MachOWriter.cpp?rev=369298&r1=369297&r2=369298&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-objcopy/MachO/MachOWriter.cpp (original)
+++ llvm/trunk/tools/llvm-objcopy/MachO/MachOWriter.cpp Mon Aug 19 14:05:31 2019
@@ -7,6 +7,7 @@
//===----------------------------------------------------------------------===//
#include "MachOWriter.h"
+#include "MachOLayoutBuilder.h"
#include "Object.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/BinaryFormat/MachO.h"
@@ -40,16 +41,10 @@ size_t MachOWriter::totalSize() const {
const MachO::symtab_command &SymTabCommand =
O.LoadCommands[*O.SymTabCommandIndex]
.MachOLoadCommand.symtab_command_data;
- if (SymTabCommand.symoff) {
- assert((SymTabCommand.nsyms == O.SymTable.Symbols.size()) &&
- "Incorrect number of symbols");
+ if (SymTabCommand.symoff)
Ends.push_back(SymTabCommand.symoff + symTableSize());
- }
- if (SymTabCommand.stroff) {
- assert((SymTabCommand.strsize == StrTableBuilder.getSize()) &&
- "Incorrect string table size");
+ if (SymTabCommand.stroff)
Ends.push_back(SymTabCommand.stroff + SymTabCommand.strsize);
- }
}
if (O.DyLdInfoCommandIndex) {
const MachO::dyld_info_command &DyLdInfoCommand =
@@ -84,6 +79,36 @@ size_t MachOWriter::totalSize() const {
}
}
+ if (O.DySymTabCommandIndex) {
+ const MachO::dysymtab_command &DySymTabCommand =
+ O.LoadCommands[*O.DySymTabCommandIndex]
+ .MachOLoadCommand.dysymtab_command_data;
+
+ if (DySymTabCommand.indirectsymoff)
+ Ends.push_back(DySymTabCommand.indirectsymoff +
+ sizeof(uint32_t) * O.IndirectSymTable.Symbols.size());
+ }
+
+ if (O.DataInCodeCommandIndex) {
+ const MachO::linkedit_data_command &LinkEditDataCommand =
+ O.LoadCommands[*O.DataInCodeCommandIndex]
+ .MachOLoadCommand.linkedit_data_command_data;
+
+ if (LinkEditDataCommand.dataoff)
+ Ends.push_back(LinkEditDataCommand.dataoff +
+ LinkEditDataCommand.datasize);
+ }
+
+ if (O.FunctionStartsCommandIndex) {
+ const MachO::linkedit_data_command &LinkEditDataCommand =
+ O.LoadCommands[*O.FunctionStartsCommandIndex]
+ .MachOLoadCommand.linkedit_data_command_data;
+
+ if (LinkEditDataCommand.dataoff)
+ Ends.push_back(LinkEditDataCommand.dataoff +
+ LinkEditDataCommand.datasize);
+ }
+
// Otherwise, use the last section / reloction.
for (const auto &LC : O.LoadCommands)
for (const auto &S : LC.Sections) {
@@ -120,14 +145,6 @@ void MachOWriter::writeHeader() {
memcpy(B.getBufferStart(), &Header, HeaderSize);
}
-void MachOWriter::updateSymbolIndexes() {
- uint32_t Index = 0;
- for (auto &Symbol : O.SymTable.Symbols) {
- Symbol->Index = Index;
- Index++;
- }
-}
-
void MachOWriter::writeLoadCommands() {
uint8_t *Begin = B.getBufferStart() + headerSize();
for (const auto &LC : O.LoadCommands) {
@@ -261,7 +278,7 @@ void MachOWriter::writeSymbolTable() {
.MachOLoadCommand.symtab_command_data;
uint8_t *StrTable = (uint8_t *)B.getBufferStart() + SymTabCommand.stroff;
- StrTableBuilder.write(StrTable);
+ LayoutBuilder.getStringTableBuilder().write(StrTable);
}
void MachOWriter::writeStringTable() {
@@ -275,7 +292,7 @@ void MachOWriter::writeStringTable() {
for (auto Iter = O.SymTable.Symbols.begin(), End = O.SymTable.Symbols.end();
Iter != End; Iter++) {
SymbolEntry *Sym = Iter->get();
- auto Nstrx = StrTableBuilder.getOffset(Sym->Name);
+ uint32_t Nstrx = LayoutBuilder.getStringTableBuilder().getOffset(Sym->Name);
if (Is64Bit)
writeNListEntry<MachO::nlist_64>(*Sym, IsLittleEndian, SymTable, Nstrx);
@@ -344,6 +361,45 @@ void MachOWriter::writeExportInfo() {
memcpy(Out, O.Exports.Trie.data(), O.Exports.Trie.size());
}
+void MachOWriter::writeIndirectSymbolTable() {
+ if (!O.DySymTabCommandIndex)
+ return;
+
+ const MachO::dysymtab_command &DySymTabCommand =
+ O.LoadCommands[*O.DySymTabCommandIndex]
+ .MachOLoadCommand.dysymtab_command_data;
+
+ char *Out = (char *)B.getBufferStart() + DySymTabCommand.indirectsymoff;
+ assert((DySymTabCommand.nindirectsyms == O.IndirectSymTable.Symbols.size()) &&
+ "Incorrect indirect symbol table size");
+ memcpy(Out, O.IndirectSymTable.Symbols.data(),
+ sizeof(uint32_t) * O.IndirectSymTable.Symbols.size());
+}
+
+void MachOWriter::writeDataInCodeData() {
+ if (!O.DataInCodeCommandIndex)
+ return;
+ const MachO::linkedit_data_command &LinkEditDataCommand =
+ O.LoadCommands[*O.DataInCodeCommandIndex]
+ .MachOLoadCommand.linkedit_data_command_data;
+ char *Out = (char *)B.getBufferStart() + LinkEditDataCommand.dataoff;
+ assert((LinkEditDataCommand.datasize == O.DataInCode.Data.size()) &&
+ "Incorrect data in code data size");
+ memcpy(Out, O.DataInCode.Data.data(), O.DataInCode.Data.size());
+}
+
+void MachOWriter::writeFunctionStartsData() {
+ if (!O.FunctionStartsCommandIndex)
+ return;
+ const MachO::linkedit_data_command &LinkEditDataCommand =
+ O.LoadCommands[*O.FunctionStartsCommandIndex]
+ .MachOLoadCommand.linkedit_data_command_data;
+ char *Out = (char *)B.getBufferStart() + LinkEditDataCommand.dataoff;
+ assert((LinkEditDataCommand.datasize == O.FunctionStarts.Data.size()) &&
+ "Incorrect function starts data size");
+ memcpy(Out, O.FunctionStarts.Data.data(), O.FunctionStarts.Data.size());
+}
+
void MachOWriter::writeTail() {
typedef void (MachOWriter::*WriteHandlerType)(void);
typedef std::pair<uint64_t, WriteHandlerType> WriteOperation;
@@ -379,6 +435,36 @@ void MachOWriter::writeTail() {
{DyLdInfoCommand.export_off, &MachOWriter::writeExportInfo});
}
+ if (O.DySymTabCommandIndex) {
+ const MachO::dysymtab_command &DySymTabCommand =
+ O.LoadCommands[*O.DySymTabCommandIndex]
+ .MachOLoadCommand.dysymtab_command_data;
+
+ if (DySymTabCommand.indirectsymoff)
+ Queue.emplace_back(DySymTabCommand.indirectsymoff,
+ &MachOWriter::writeIndirectSymbolTable);
+ }
+
+ if (O.DataInCodeCommandIndex) {
+ const MachO::linkedit_data_command &LinkEditDataCommand =
+ O.LoadCommands[*O.DataInCodeCommandIndex]
+ .MachOLoadCommand.linkedit_data_command_data;
+
+ if (LinkEditDataCommand.dataoff)
+ Queue.emplace_back(LinkEditDataCommand.dataoff,
+ &MachOWriter::writeDataInCodeData);
+ }
+
+ if (O.FunctionStartsCommandIndex) {
+ const MachO::linkedit_data_command &LinkEditDataCommand =
+ O.LoadCommands[*O.FunctionStartsCommandIndex]
+ .MachOLoadCommand.linkedit_data_command_data;
+
+ if (LinkEditDataCommand.dataoff)
+ Queue.emplace_back(LinkEditDataCommand.dataoff,
+ &MachOWriter::writeFunctionStartsData);
+ }
+
llvm::sort(Queue, [](const WriteOperation &LHS, const WriteOperation &RHS) {
return LHS.first < RHS.first;
});
@@ -387,198 +473,13 @@ void MachOWriter::writeTail() {
(this->*WriteOp.second)();
}
-void MachOWriter::updateSizeOfCmds() {
- auto Size = 0;
- for (const auto &LC : O.LoadCommands) {
- auto &MLC = LC.MachOLoadCommand;
- auto cmd = MLC.load_command_data.cmd;
-
- switch (cmd) {
- case MachO::LC_SEGMENT:
- Size += sizeof(MachO::segment_command) +
- sizeof(MachO::section) * LC.Sections.size();
- continue;
- case MachO::LC_SEGMENT_64:
- Size += sizeof(MachO::segment_command_64) +
- sizeof(MachO::section_64) * LC.Sections.size();
- continue;
- }
-
- switch (cmd) {
-#define HANDLE_LOAD_COMMAND(LCName, LCValue, LCStruct) \
- case MachO::LCName: \
- Size += sizeof(MachO::LCStruct); \
- break;
-#include "llvm/BinaryFormat/MachO.def"
-#undef HANDLE_LOAD_COMMAND
- }
- }
-
- O.Header.SizeOfCmds = Size;
-}
-
-// Updates the index and the number of local/external/undefined symbols. Here we
-// assume that MLC is a LC_DYSYMTAB and the nlist entries in the symbol table
-// are already sorted by the those types.
-void MachOWriter::updateDySymTab(MachO::macho_load_command &MLC) {
- uint32_t NumLocalSymbols = 0;
- auto Iter = O.SymTable.Symbols.begin();
- auto End = O.SymTable.Symbols.end();
- for (; Iter != End; Iter++) {
- if ((*Iter)->n_type & (MachO::N_EXT | MachO::N_PEXT))
- break;
-
- NumLocalSymbols++;
- }
-
- uint32_t NumExtDefSymbols = 0;
- for (; Iter != End; Iter++) {
- if (((*Iter)->n_type & MachO::N_TYPE) == MachO::N_UNDF)
- break;
-
- NumExtDefSymbols++;
- }
-
- MLC.dysymtab_command_data.ilocalsym = 0;
- MLC.dysymtab_command_data.nlocalsym = NumLocalSymbols;
- MLC.dysymtab_command_data.iextdefsym = NumLocalSymbols;
- MLC.dysymtab_command_data.nextdefsym = NumExtDefSymbols;
- MLC.dysymtab_command_data.iundefsym = NumLocalSymbols + NumExtDefSymbols;
- MLC.dysymtab_command_data.nundefsym =
- O.SymTable.Symbols.size() - (NumLocalSymbols + NumExtDefSymbols);
-}
-
-// Recomputes and updates offset and size fields in load commands and sections
-// since they could be modified.
-Error MachOWriter::layout() {
- auto SizeOfCmds = loadCommandsSize();
- auto Offset = headerSize() + SizeOfCmds;
- O.Header.NCmds = O.LoadCommands.size();
- O.Header.SizeOfCmds = SizeOfCmds;
-
- // Lay out sections.
- for (auto &LC : O.LoadCommands) {
- uint64_t FileOff = Offset;
- uint64_t VMSize = 0;
- uint64_t FileOffsetInSegment = 0;
- for (auto &Sec : LC.Sections) {
- if (!Sec.isVirtualSection()) {
- auto FilePaddingSize =
- OffsetToAlignment(FileOffsetInSegment, 1ull << Sec.Align);
- Sec.Offset = Offset + FileOffsetInSegment + FilePaddingSize;
- Sec.Size = Sec.Content.size();
- FileOffsetInSegment += FilePaddingSize + Sec.Size;
- }
-
- VMSize = std::max(VMSize, Sec.Addr + Sec.Size);
- }
-
- // TODO: Handle the __PAGEZERO segment.
- auto &MLC = LC.MachOLoadCommand;
- switch (MLC.load_command_data.cmd) {
- case MachO::LC_SEGMENT:
- MLC.segment_command_data.cmdsize =
- sizeof(MachO::segment_command) +
- sizeof(MachO::section) * LC.Sections.size();
- MLC.segment_command_data.nsects = LC.Sections.size();
- MLC.segment_command_data.fileoff = FileOff;
- MLC.segment_command_data.vmsize = VMSize;
- MLC.segment_command_data.filesize = FileOffsetInSegment;
- break;
- case MachO::LC_SEGMENT_64:
- MLC.segment_command_64_data.cmdsize =
- sizeof(MachO::segment_command_64) +
- sizeof(MachO::section_64) * LC.Sections.size();
- MLC.segment_command_64_data.nsects = LC.Sections.size();
- MLC.segment_command_64_data.fileoff = FileOff;
- MLC.segment_command_64_data.vmsize = VMSize;
- MLC.segment_command_64_data.filesize = FileOffsetInSegment;
- break;
- }
-
- Offset += FileOffsetInSegment;
- }
-
- // Lay out relocations.
- for (auto &LC : O.LoadCommands)
- for (auto &Sec : LC.Sections) {
- Sec.RelOff = Sec.Relocations.empty() ? 0 : Offset;
- Sec.NReloc = Sec.Relocations.size();
- Offset += sizeof(MachO::any_relocation_info) * Sec.NReloc;
- }
-
- // Lay out tail stuff.
- auto NListSize = Is64Bit ? sizeof(MachO::nlist_64) : sizeof(MachO::nlist);
- for (auto &LC : O.LoadCommands) {
- auto &MLC = LC.MachOLoadCommand;
- auto cmd = MLC.load_command_data.cmd;
- switch (cmd) {
- case MachO::LC_SYMTAB:
- MLC.symtab_command_data.nsyms = O.SymTable.Symbols.size();
- MLC.symtab_command_data.strsize = StrTableBuilder.getSize();
- MLC.symtab_command_data.symoff = Offset;
- Offset += NListSize * MLC.symtab_command_data.nsyms;
- MLC.symtab_command_data.stroff = Offset;
- Offset += MLC.symtab_command_data.strsize;
- break;
- case MachO::LC_DYSYMTAB: {
- if (MLC.dysymtab_command_data.ntoc != 0 ||
- MLC.dysymtab_command_data.nmodtab != 0 ||
- MLC.dysymtab_command_data.nextrefsyms != 0 ||
- MLC.dysymtab_command_data.nlocrel != 0 ||
- MLC.dysymtab_command_data.nextrel != 0)
- return createStringError(llvm::errc::not_supported,
- "shared library is not yet supported");
-
- if (MLC.dysymtab_command_data.nindirectsyms != 0)
- return createStringError(llvm::errc::not_supported,
- "indirect symbol table is not yet supported");
-
- updateDySymTab(MLC);
- break;
- }
- case MachO::LC_SEGMENT:
- case MachO::LC_SEGMENT_64:
- case MachO::LC_VERSION_MIN_MACOSX:
- case MachO::LC_BUILD_VERSION:
- case MachO::LC_ID_DYLIB:
- case MachO::LC_LOAD_DYLIB:
- case MachO::LC_UUID:
- case MachO::LC_SOURCE_VERSION:
- // Nothing to update.
- break;
- default:
- // Abort if it's unsupported in order to prevent corrupting the object.
- return createStringError(llvm::errc::not_supported,
- "unsupported load command (cmd=0x%x)", cmd);
- }
- }
-
- return Error::success();
-}
-
-void MachOWriter::constructStringTable() {
- for (std::unique_ptr<SymbolEntry> &Sym : O.SymTable.Symbols)
- StrTableBuilder.add(Sym->Name);
- StrTableBuilder.finalize();
-}
-
-Error MachOWriter::finalize() {
- updateSizeOfCmds();
- constructStringTable();
-
- if (auto E = layout())
- return E;
-
- return Error::success();
-}
+Error MachOWriter::finalize() { return LayoutBuilder.layout(); }
Error MachOWriter::write() {
if (Error E = B.allocate(totalSize()))
return E;
memset(B.getBufferStart(), 0, totalSize());
writeHeader();
- updateSymbolIndexes();
writeLoadCommands();
writeSections();
writeTail();
Modified: llvm/trunk/tools/llvm-objcopy/MachO/MachOWriter.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objcopy/MachO/MachOWriter.h?rev=369298&r1=369297&r2=369298&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-objcopy/MachO/MachOWriter.h (original)
+++ llvm/trunk/tools/llvm-objcopy/MachO/MachOWriter.h Mon Aug 19 14:05:31 2019
@@ -7,6 +7,7 @@
//===----------------------------------------------------------------------===//
#include "../Buffer.h"
+#include "MachOLayoutBuilder.h"
#include "MachOObjcopy.h"
#include "Object.h"
#include "llvm/BinaryFormat/MachO.h"
@@ -22,20 +23,15 @@ class MachOWriter {
Object &O;
bool Is64Bit;
bool IsLittleEndian;
+ uint64_t PageSize;
Buffer &B;
- StringTableBuilder StrTableBuilder{StringTableBuilder::MachO};
+ MachOLayoutBuilder LayoutBuilder;
size_t headerSize() const;
size_t loadCommandsSize() const;
size_t symTableSize() const;
size_t strTableSize() const;
- void updateDySymTab(MachO::macho_load_command &MLC);
- void updateSizeOfCmds();
- void updateSymbolIndexes();
- void constructStringTable();
- Error layout();
-
void writeHeader();
void writeLoadCommands();
template <typename StructType>
@@ -48,11 +44,16 @@ class MachOWriter {
void writeWeakBindInfo();
void writeLazyBindInfo();
void writeExportInfo();
+ void writeIndirectSymbolTable();
+ void writeDataInCodeData();
+ void writeFunctionStartsData();
void writeTail();
public:
- MachOWriter(Object &O, bool Is64Bit, bool IsLittleEndian, Buffer &B)
- : O(O), Is64Bit(Is64Bit), IsLittleEndian(IsLittleEndian), B(B) {}
+ MachOWriter(Object &O, bool Is64Bit, bool IsLittleEndian, uint64_t PageSize,
+ Buffer &B)
+ : O(O), Is64Bit(Is64Bit), IsLittleEndian(IsLittleEndian),
+ PageSize(PageSize), B(B), LayoutBuilder(O, Is64Bit, PageSize) {}
size_t totalSize() const;
Error finalize();
Modified: llvm/trunk/tools/llvm-objcopy/MachO/Object.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objcopy/MachO/Object.h?rev=369298&r1=369297&r2=369298&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-objcopy/MachO/Object.h (original)
+++ llvm/trunk/tools/llvm-objcopy/MachO/Object.h Mon Aug 19 14:05:31 2019
@@ -90,6 +90,16 @@ struct SymbolEntry {
uint8_t n_sect;
uint16_t n_desc;
uint64_t n_value;
+
+ bool isExternalSymbol() const {
+ return n_type & ((MachO::N_EXT | MachO::N_PEXT));
+ }
+
+ bool isLocalSymbol() const { return !isExternalSymbol(); }
+
+ bool isUndefinedSymbol() const {
+ return (n_type & MachO::N_TYPE) == MachO::N_UNDF;
+ }
};
/// The location of the symbol table inside the binary is described by LC_SYMTAB
@@ -100,6 +110,10 @@ struct SymbolTable {
const SymbolEntry *getSymbolByIndex(uint32_t Index) const;
};
+struct IndirectSymbolTable {
+ std::vector<uint32_t> Symbols;
+};
+
/// The location of the string table inside the binary is described by LC_SYMTAB
/// load command.
struct StringTable {
@@ -206,6 +220,10 @@ struct ExportInfo {
ArrayRef<uint8_t> Trie;
};
+struct LinkData {
+ ArrayRef<uint8_t> Data;
+};
+
struct Object {
MachHeader Header;
std::vector<LoadCommand> LoadCommands;
@@ -218,11 +236,20 @@ struct Object {
WeakBindInfo WeakBinds;
LazyBindInfo LazyBinds;
ExportInfo Exports;
+ IndirectSymbolTable IndirectSymTable;
+ LinkData DataInCode;
+ LinkData FunctionStarts;
/// The index of LC_SYMTAB load command if present.
Optional<size_t> SymTabCommandIndex;
/// The index of LC_DYLD_INFO or LC_DYLD_INFO_ONLY load command if present.
Optional<size_t> DyLdInfoCommandIndex;
+ /// The index LC_DYSYMTAB load comamnd if present.
+ Optional<size_t> DySymTabCommandIndex;
+ /// The index LC_DATA_IN_CODE load comamnd if present.
+ Optional<size_t> DataInCodeCommandIndex;
+ /// The index LC_FUNCTION_STARTS load comamnd if present.
+ Optional<size_t> FunctionStartsCommandIndex;
};
} // end namespace macho
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