Add a MachO-specific "mode" to llvm-objdump, that, if enabled, gathers additional information that are only available on MachO.
- It can take FunctionStarts from a binary to find entry points more accurately.
- Symbol offsets in executables are correct now.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140028 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/llvm-objdump/MachODump.cpp b/tools/llvm-objdump/MachODump.cpp
new file mode 100644
index 0000000..49687d1
--- /dev/null
+++ b/tools/llvm-objdump/MachODump.cpp
@@ -0,0 +1,489 @@
+//===-- MachODump.cpp - Object file dumping utility for llvm --------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the MachO-specific dumper for llvm-objdump.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm-objdump.h"
+#include "MCFunction.h"
+#include "llvm/Support/MachO.h"
+#include "llvm/Object/MachOObject.h"
+#include "llvm/ADT/OwningPtr.h"
+#include "llvm/ADT/Triple.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCDisassembler.h"
+#include "llvm/MC/MCInst.h"
+#include "llvm/MC/MCInstPrinter.h"
+#include "llvm/MC/MCInstrAnalysis.h"
+#include "llvm/MC/MCInstrDesc.h"
+#include "llvm/MC/MCInstrInfo.h"
+#include "llvm/MC/MCSubtargetInfo.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/Format.h"
+#include "llvm/Support/GraphWriter.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Support/TargetSelect.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/system_error.h"
+#include <algorithm>
+#include <cstring>
+using namespace llvm;
+using namespace object;
+
+static cl::opt<bool>
+ CFG("cfg", cl::desc("Create a CFG for every symbol in the object file and"
+ "write it to a graphviz file (MachO-only)"));
+
+static const Target *GetTarget(const MachOObject *MachOObj) {
+ // Figure out the target triple.
+ llvm::Triple TT("unknown-unknown-unknown");
+ switch (MachOObj->getHeader().CPUType) {
+ case llvm::MachO::CPUTypeI386:
+ TT.setArch(Triple::ArchType(Triple::x86));
+ break;
+ case llvm::MachO::CPUTypeX86_64:
+ TT.setArch(Triple::ArchType(Triple::x86_64));
+ break;
+ case llvm::MachO::CPUTypeARM:
+ TT.setArch(Triple::ArchType(Triple::arm));
+ break;
+ case llvm::MachO::CPUTypePowerPC:
+ TT.setArch(Triple::ArchType(Triple::ppc));
+ break;
+ case llvm::MachO::CPUTypePowerPC64:
+ TT.setArch(Triple::ArchType(Triple::ppc64));
+ break;
+ }
+
+ TripleName = TT.str();
+
+ // Get the target specific parser.
+ std::string Error;
+ const Target *TheTarget = TargetRegistry::lookupTarget(TripleName, Error);
+ if (TheTarget)
+ return TheTarget;
+
+ errs() << "llvm-objdump: error: unable to get target for '" << TripleName
+ << "', see --version and --triple.\n";
+ return 0;
+}
+
+struct Section {
+ char Name[16];
+ uint64_t Address;
+ uint64_t Size;
+ uint32_t Offset;
+ uint32_t NumRelocs;
+ uint64_t RelocTableOffset;
+};
+
+struct Symbol {
+ uint64_t Value;
+ uint32_t StringIndex;
+ uint8_t SectionIndex;
+ bool operator<(const Symbol &RHS) const { return Value < RHS.Value; }
+};
+
+static void DumpAddress(uint64_t Address, ArrayRef<Section> Sections,
+ MachOObject *MachOObj, raw_ostream &OS) {
+ for (unsigned i = 0; i != Sections.size(); ++i) {
+ uint64_t addr = Address-Sections[i].Address;
+ if (Sections[i].Address <= Address &&
+ Sections[i].Address + Sections[i].Size > Address) {
+ StringRef bytes = MachOObj->getData(Sections[i].Offset,
+ Sections[i].Size);
+ if (!strcmp(Sections[i].Name, "__cstring"))
+ OS << '"' << bytes.substr(addr, bytes.find('\0', addr)) << '"';
+ if (!strcmp(Sections[i].Name, "__cfstring"))
+ OS << "@\"" << bytes.substr(addr, bytes.find('\0', addr)) << '"';
+ }
+ }
+}
+
+void llvm::DisassembleInputMachO(StringRef Filename) {
+ OwningPtr<MemoryBuffer> Buff;
+
+ if (error_code ec = MemoryBuffer::getFileOrSTDIN(Filename, Buff)) {
+ errs() << "llvm-objdump: " << Filename << ": " << ec.message() << "\n";
+ return;
+ }
+
+ OwningPtr<MachOObject> MachOObj(MachOObject::LoadFromBuffer(Buff.take()));
+
+ const Target *TheTarget = GetTarget(MachOObj.get());
+ if (!TheTarget) {
+ // GetTarget prints out stuff.
+ return;
+ }
+ const MCInstrInfo *InstrInfo = TheTarget->createMCInstrInfo();
+ OwningPtr<MCInstrAnalysis>
+ InstrAnalysis(TheTarget->createMCInstrAnalysis(InstrInfo));
+
+ // Set up disassembler.
+ OwningPtr<const MCAsmInfo> AsmInfo(TheTarget->createMCAsmInfo(TripleName));
+
+ if (!AsmInfo) {
+ errs() << "error: no assembly info for target " << TripleName << "\n";
+ return;
+ }
+
+ OwningPtr<const MCSubtargetInfo>
+ STI(TheTarget->createMCSubtargetInfo(TripleName, "", ""));
+
+ if (!STI) {
+ errs() << "error: no subtarget info for target " << TripleName << "\n";
+ return;
+ }
+
+ OwningPtr<const MCDisassembler> DisAsm(TheTarget->createMCDisassembler(*STI));
+ if (!DisAsm) {
+ errs() << "error: no disassembler for target " << TripleName << "\n";
+ return;
+ }
+
+ int AsmPrinterVariant = AsmInfo->getAssemblerDialect();
+ OwningPtr<MCInstPrinter> IP(TheTarget->createMCInstPrinter(
+ AsmPrinterVariant, *AsmInfo, *STI));
+ if (!IP) {
+ errs() << "error: no instruction printer for target " << TripleName << '\n';
+ return;
+ }
+
+ outs() << '\n';
+ outs() << Filename << ":\n\n";
+
+ const macho::Header &Header = MachOObj->getHeader();
+
+ const MachOObject::LoadCommandInfo *SymtabLCI = 0;
+ for (unsigned i = 0; i != Header.NumLoadCommands; ++i) {
+ const MachOObject::LoadCommandInfo &LCI = MachOObj->getLoadCommandInfo(i);
+ switch (LCI.Command.Type) {
+ case macho::LCT_Symtab:
+ SymtabLCI = &LCI;
+ break;
+ }
+ }
+
+ // Read and register the symbol table data.
+ InMemoryStruct<macho::SymtabLoadCommand> SymtabLC;
+ MachOObj->ReadSymtabLoadCommand(*SymtabLCI, SymtabLC);
+ MachOObj->RegisterStringTable(*SymtabLC);
+
+ std::vector<Section> Sections;
+ std::vector<Symbol> Symbols;
+ std::vector<Symbol> UnsortedSymbols; // FIXME: duplication
+ SmallVector<uint64_t, 8> FoundFns;
+
+ for (unsigned i = 0; i != Header.NumLoadCommands; ++i) {
+ const MachOObject::LoadCommandInfo &LCI = MachOObj->getLoadCommandInfo(i);
+ if (LCI.Command.Type == macho::LCT_Segment) {
+ InMemoryStruct<macho::SegmentLoadCommand> SegmentLC;
+ MachOObj->ReadSegmentLoadCommand(LCI, SegmentLC);
+
+ for (unsigned SectNum = 0; SectNum != SegmentLC->NumSections; ++SectNum) {
+ InMemoryStruct<macho::Section> Sect;
+ MachOObj->ReadSection(LCI, SectNum, Sect);
+
+ Section S;
+ memcpy(S.Name, Sect->Name, 16);
+ S.Address = Sect->Address;
+ S.Size = Sect->Size;
+ S.Offset = Sect->Offset;
+ S.NumRelocs = Sect->NumRelocationTableEntries;
+ S.RelocTableOffset = Sect->RelocationTableOffset;
+ Sections.push_back(S);
+
+ for (unsigned i = 0; i != SymtabLC->NumSymbolTableEntries; ++i) {
+ InMemoryStruct<macho::SymbolTableEntry> STE;
+ MachOObj->ReadSymbolTableEntry(SymtabLC->SymbolTableOffset, i, STE);
+
+ Symbol S;
+ S.StringIndex = STE->StringIndex;
+ S.SectionIndex = STE->SectionIndex;
+ S.Value = STE->Value;
+ Symbols.push_back(S);
+ UnsortedSymbols.push_back(Symbols.back());
+ }
+ }
+ } else if (LCI.Command.Type == macho::LCT_Segment64) {
+ InMemoryStruct<macho::Segment64LoadCommand> Segment64LC;
+ MachOObj->ReadSegment64LoadCommand(LCI, Segment64LC);
+
+ for (unsigned SectNum = 0; SectNum != Segment64LC->NumSections; ++SectNum) {
+ InMemoryStruct<macho::Section64> Sect64;
+ MachOObj->ReadSection64(LCI, SectNum, Sect64);
+
+ Section S;
+ memcpy(S.Name, Sect64->Name, 16);
+ S.Address = Sect64->Address;
+ S.Size = Sect64->Size;
+ S.Offset = Sect64->Offset;
+ S.NumRelocs = Sect64->NumRelocationTableEntries;
+ S.RelocTableOffset = Sect64->RelocationTableOffset;
+ Sections.push_back(S);
+
+ for (unsigned i = 0; i != SymtabLC->NumSymbolTableEntries; ++i) {
+ InMemoryStruct<macho::Symbol64TableEntry> STE;
+ MachOObj->ReadSymbol64TableEntry(SymtabLC->SymbolTableOffset, i, STE);
+
+ Symbol S;
+ S.StringIndex = STE->StringIndex;
+ S.SectionIndex = STE->SectionIndex;
+ S.Value = STE->Value;
+ Symbols.push_back(S);
+ UnsortedSymbols.push_back(Symbols.back());
+ }
+ }
+ } else if (LCI.Command.Type == macho::LCT_FunctionStarts) {
+ InMemoryStruct<macho::LinkeditDataLoadCommand> LLC;
+ MachOObj->ReadLinkeditDataLoadCommand(LCI, LLC);
+
+ MachOObj->ReadULEB128s(LLC->DataOffset, FoundFns);
+ }
+ }
+
+ std::map<uint64_t, MCFunction*> FunctionMap;
+
+ // Sort the symbols by address, just in case they didn't come in that way.
+ array_pod_sort(Symbols.begin(), Symbols.end());
+
+#ifndef NDEBUG
+ raw_ostream &DebugOut = DebugFlag ? dbgs() : nulls();
+#else
+ raw_ostream &DebugOut = nulls();
+#endif
+
+ SmallVector<MCFunction, 16> Functions;
+
+ for (unsigned SectIdx = 0; SectIdx != Sections.size(); SectIdx++) {
+ if (strcmp(Sections[SectIdx].Name, "__text"))
+ continue;
+
+ uint64_t VMAddr = Sections[SectIdx].Address - Sections[SectIdx].Offset;
+ for (unsigned i = 0, e = FoundFns.size(); i != e; ++i)
+ FunctionMap.insert(std::pair<uint64_t,MCFunction*>(FoundFns[i]+VMAddr,0));
+
+ StringRef Bytes = MachOObj->getData(Sections[SectIdx].Offset,
+ Sections[SectIdx].Size);
+ StringRefMemoryObject memoryObject(Bytes);
+ bool symbolTableWorked = false;
+
+ std::vector<std::pair<uint64_t, uint32_t> > Relocs;
+ for (unsigned j = 0; j != Sections[SectIdx].NumRelocs; ++j) {
+ InMemoryStruct<macho::RelocationEntry> RE;
+ MachOObj->ReadRelocationEntry(Sections[SectIdx].RelocTableOffset, j, RE);
+ Relocs.push_back(std::make_pair(RE->Word0, RE->Word1 & 0xffffff));
+ }
+ array_pod_sort(Relocs.begin(), Relocs.end());
+
+ for (unsigned SymIdx = 0; SymIdx != Symbols.size(); SymIdx++) {
+ if ((unsigned)Symbols[SymIdx].SectionIndex - 1 != SectIdx)
+ continue;
+
+ uint64_t Start = Symbols[SymIdx].Value - Sections[SectIdx].Address;
+ uint64_t End = (SymIdx+1 == Symbols.size() ||
+ Symbols[SymIdx].SectionIndex != Symbols[SymIdx+1].SectionIndex) ?
+ Sections[SectIdx].Size :
+ Symbols[SymIdx+1].Value - Sections[SectIdx].Address;
+ uint64_t Size;
+
+ if (Start >= End)
+ continue;
+
+ symbolTableWorked = true;
+
+ if (!CFG) {
+ outs() << MachOObj->getStringAtIndex(Symbols[SymIdx].StringIndex)
+ << ":\n";
+ for (uint64_t Index = Start; Index < End; Index += Size) {
+ MCInst Inst;
+
+ if (DisAsm->getInstruction(Inst, Size, memoryObject, Index,
+ DebugOut, nulls())) {
+ outs() << format("%8llx:\t", Sections[SectIdx].Address + Index);
+ DumpBytes(StringRef(Bytes.data() + Index, Size));
+ IP->printInst(&Inst, outs(), "");
+ outs() << "\n";
+ } else {
+ errs() << "llvm-objdump: warning: invalid instruction encoding\n";
+ if (Size == 0)
+ Size = 1; // skip illegible bytes
+ }
+ }
+ } else {
+ // Create CFG and use it for disassembly.
+ SmallVector<uint64_t, 16> Calls;
+ MCFunction f =
+ MCFunction::createFunctionFromMC(
+ MachOObj->getStringAtIndex(Symbols[SymIdx].StringIndex),
+ DisAsm.get(),
+ memoryObject, Start, End,
+ InstrAnalysis.get(), DebugOut,
+ Calls);
+
+ Functions.push_back(f);
+ FunctionMap[Start] = &Functions.back();
+
+ for (unsigned i = 0, e = Calls.size(); i != e; ++i)
+ FunctionMap.insert(std::pair<uint64_t, MCFunction*>(Calls[i], 0));
+ }
+ }
+
+ if (CFG) {
+ if (!symbolTableWorked) {
+ // Create CFG and use it for disassembly.
+ SmallVector<uint64_t, 16> Calls;
+ MCFunction f =
+ MCFunction::createFunctionFromMC("__TEXT", DisAsm.get(),
+ memoryObject, 0, Sections[SectIdx].Size,
+ InstrAnalysis.get(), DebugOut,
+ Calls);
+
+ Functions.push_back(f);
+ FunctionMap[Sections[SectIdx].Offset] = &Functions.back();
+
+ for (unsigned i = 0, e = Calls.size(); i != e; ++i)
+ FunctionMap.insert(std::pair<uint64_t, MCFunction*>(Calls[i], 0));
+ }
+ for (std::map<uint64_t, MCFunction*>::iterator mi = FunctionMap.begin(),
+ me = FunctionMap.end(); mi != me; ++mi)
+ if (mi->second == 0) {
+ SmallVector<uint64_t, 16> Calls;
+ MCFunction f =
+ MCFunction::createFunctionFromMC("unknown", DisAsm.get(),
+ memoryObject, mi->first,
+ Sections[SectIdx].Size,
+ InstrAnalysis.get(), DebugOut,
+ Calls);
+ Functions.push_back(f);
+ mi->second = &Functions.back();
+ for (unsigned i = 0, e = Calls.size(); i != e; ++i)
+ if (FunctionMap.insert(std::pair<uint64_t, MCFunction*>(Calls[i],0))
+ .second)
+ mi = FunctionMap.begin();
+ }
+
+ DenseSet<uint64_t> PrintedBlocks;
+ for (unsigned ffi = 0, ffe = Functions.size(); ffi != ffe; ++ffi) {
+ MCFunction &f = Functions[ffi];
+ for (MCFunction::iterator fi = f.begin(), fe = f.end(); fi != fe; ++fi){
+ if (!PrintedBlocks.insert(fi->first).second)
+ continue;
+ bool hasPreds = FunctionMap.find(fi->first) != FunctionMap.end();
+
+ // Only print blocks that have predecessors.
+ // FIXME: Slow.
+ for (MCFunction::iterator pi = f.begin(), pe = f.end(); pi != pe;
+ ++pi)
+ if (pi->second.contains(fi->first)) {
+ hasPreds = true;
+ break;
+ }
+
+ // Data block.
+ if (!hasPreds && fi != f.begin()) {
+ uint64_t End = llvm::next(fi) == fe ? Sections[SectIdx].Size :
+ llvm::next(fi)->first;
+ outs() << "# " << End-fi->first << " bytes of data:\n";
+ for (unsigned pos = fi->first; pos != End; ++pos) {
+ outs() << format("%8x:\t", Sections[SectIdx].Address + pos);
+ DumpBytes(StringRef(Bytes.data() + pos, 1));
+ outs() << format("\t.byte 0x%02x\n", (uint8_t)Bytes[pos]);
+ }
+ continue;
+ }
+
+ if (fi->second.contains(fi->first))
+ outs() << "# Loop begin:\n";
+
+ for (unsigned ii = 0, ie = fi->second.getInsts().size(); ii != ie;
+ ++ii) {
+ const MCDecodedInst &Inst = fi->second.getInsts()[ii];
+ if (FunctionMap.find(Sections[SectIdx].Address + Inst.Address) !=
+ FunctionMap.end())
+ outs() << FunctionMap[Sections[SectIdx].Address + Inst.Address]->
+ getName() << ":\n";
+ outs() << format("%8llx:\t", Sections[SectIdx].Address +
+ Inst.Address);
+ DumpBytes(StringRef(Bytes.data() + Inst.Address, Inst.Size));
+ // Simple loops.
+ if (fi->second.contains(fi->first))
+ outs() << '\t';
+ IP->printInst(&Inst.Inst, outs(), "");
+ for (unsigned j = 0; j != Relocs.size(); ++j)
+ if (Relocs[j].first >= Sections[SectIdx].Address + Inst.Address &&
+ Relocs[j].first < Sections[SectIdx].Address + Inst.Address +
+ Inst.Size) {
+ outs() << "\t# "
+ << MachOObj->getStringAtIndex(
+ UnsortedSymbols[Relocs[j].second].StringIndex)
+ << ' ';
+ DumpAddress(UnsortedSymbols[Relocs[j].second].Value, Sections,
+ MachOObj.get(), outs());
+ }
+ uint64_t targ = InstrAnalysis->evaluateBranch(Inst.Inst,
+ Inst.Address,
+ Inst.Size);
+ if (targ != -1ULL)
+ DumpAddress(targ, Sections, MachOObj.get(), outs());
+
+ outs() << '\n';
+ }
+ }
+
+ // Start a new dot file.
+ std::string Error;
+ raw_fd_ostream Out((f.getName().str() + ".dot").c_str(), Error);
+ if (!Error.empty()) {
+ errs() << "llvm-objdump: warning: " << Error << '\n';
+ continue;
+ }
+
+ Out << "digraph " << f.getName() << " {\n";
+ Out << "graph [ rankdir = \"LR\" ];\n";
+ for (MCFunction::iterator i = f.begin(), e = f.end(); i != e; ++i) {
+ bool hasPreds = false;
+ // Only print blocks that have predecessors.
+ // FIXME: Slow.
+ for (MCFunction::iterator pi = f.begin(), pe = f.end(); pi != pe;
+ ++pi)
+ if (pi->second.contains(i->first)) {
+ hasPreds = true;
+ break;
+ }
+
+ if (!hasPreds && i != f.begin())
+ continue;
+
+ Out << '"' << i->first << "\" [ label=\"<a>";
+ // Print instructions.
+ for (unsigned ii = 0, ie = i->second.getInsts().size(); ii != ie;
+ ++ii) {
+ // Escape special chars and print the instruction in mnemonic form.
+ std::string Str;
+ raw_string_ostream OS(Str);
+ IP->printInst(&i->second.getInsts()[ii].Inst, OS, "");
+ Out << DOT::EscapeString(OS.str()) << '|';
+ }
+ Out << "<o>\" shape=\"record\" ];\n";
+
+ // Add edges.
+ for (MCBasicBlock::succ_iterator si = i->second.succ_begin(),
+ se = i->second.succ_end(); si != se; ++si)
+ Out << i->first << ":o -> " << *si <<":a\n";
+ }
+ Out << "}\n";
+ }
+ }
+ }
+}