Implements low-level object file format specific output for COFF and

ELF with support for:

- File headers
- Section headers + data
- Relocations
- Symbols
- Unwind data (only COFF/Win64)

The output format follows a few rules:
- Values are almost always output one per line (as elf-dump/coff-dump already do). - Many values are translated to something readable (like enum names), with the raw value in parentheses.
- Hex numbers are output in uppercase, prefixed with "0x".
- Flags are sorted alphabetically.
- Lists and groups are always delimited.

Example output:
---------- snip ----------
Sections [
  Section {
    Index: 1
    Name: .text (5)
    Type: SHT_PROGBITS (0x1)
    Flags [ (0x6)
      SHF_ALLOC (0x2)
      SHF_EXECINSTR (0x4)
    ]
    Address: 0x0
    Offset: 0x40
    Size: 33
    Link: 0
    Info: 0
    AddressAlignment: 16
    EntrySize: 0
    Relocations [
      0x6 R_386_32 .rodata.str1.1 0x0
      0xB R_386_PC32 puts 0x0
      0x12 R_386_32 .rodata.str1.1 0x0
      0x17 R_386_PC32 puts 0x0
    ]
    SectionData (
      0000: 83EC04C7 04240000 0000E8FC FFFFFFC7  |.....$..........|
      0010: 04240600 0000E8FC FFFFFF31 C083C404  |.$.........1....|
      0020: C3                                   |.|
    )
  }
]
---------- snip ----------

Relocations and symbols can be output standalone or together with the section header as displayed in the example.
This feature set supports all tests in test/MC/COFF and test/MC/ELF (and I suspect all additional tests using elf-dump), making elf-dump and coff-dump deprecated.

Patch by Nico Rieck!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178679 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 438 insertions, 0 deletions

diff --git a/tools/llvm-readobj/MachODumper.cpp b/tools/llvm-readobj/MachODumper.cpp
new file mode 100644
index 0000000000..798c941772
--- /dev/null
+++ b/tools/llvm-readobj/MachODumper.cpp
@@ -0,0 +1,438 @@
+//===-- 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-readobj.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm-readobj.h"
+#include "Error.h"
+#include "ObjDumper.h"
+#include "StreamWriter.h"
+
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Object/MachO.h"
+#include "llvm/Support/Casting.h"
+
+using namespace llvm;
+using namespace object;
+
+namespace {
+
+class MachODumper : public ObjDumper {
+public:
+  MachODumper(const llvm::object::MachOObjectFile *Obj, StreamWriter& Writer)
+    : ObjDumper(Writer)
+    , Obj(Obj) { }
+
+  virtual void printFileHeaders() LLVM_OVERRIDE;
+  virtual void printSections() LLVM_OVERRIDE;
+  virtual void printRelocations() LLVM_OVERRIDE;
+  virtual void printSymbols() LLVM_OVERRIDE;
+  virtual void printDynamicSymbols() LLVM_OVERRIDE;
+  virtual void printUnwindInfo() LLVM_OVERRIDE;
+
+private:
+  void printSymbol(symbol_iterator SymI);
+
+  void printRelocation(section_iterator SecI, relocation_iterator RelI);
+
+  const llvm::object::MachOObjectFile *Obj;
+};
+
+} // namespace
+
+
+namespace llvm {
+
+error_code createMachODumper(const object::ObjectFile *Obj,
+                             StreamWriter& Writer,
+                             OwningPtr<ObjDumper> &Result) {
+  const MachOObjectFile *MachOObj = dyn_cast<MachOObjectFile>(Obj);
+  if (!MachOObj)
+    return readobj_error::unsupported_obj_file_format;
+
+  Result.reset(new MachODumper(MachOObj, Writer));
+  return readobj_error::success;
+}
+
+} // namespace llvm
+
+
+static const EnumEntry<unsigned> MachOSectionTypes[] = {
+  { "Regular"                        , 0x00 },
+  { "ZeroFill"                       , 0x01 },
+  { "CStringLiterals"                , 0x02 },
+  { "4ByteLiterals"                  , 0x03 },
+  { "8ByteLiterals"                  , 0x04 },
+  { "LiteralPointers"                , 0x05 },
+  { "NonLazySymbolPointers"          , 0x06 },
+  { "LazySymbolPointers"             , 0x07 },
+  { "SymbolStubs"                    , 0x08 },
+  { "ModInitFuncs"                   , 0x09 },
+  { "ModTermFuncs"                   , 0x0A },
+  { "Coalesced"                      , 0x0B },
+  { "GBZeroFill"                     , 0x0C },
+  { "Interposing"                    , 0x0D },
+  { "16ByteLiterals"                 , 0x0E },
+  { "DTraceDOF"                      , 0x0F },
+  { "LazyDylibSymbolPoints"          , 0x10 },
+  { "ThreadLocalRegular"             , 0x11 },
+  { "ThreadLocalZerofill"            , 0x12 },
+  { "ThreadLocalVariables"           , 0x13 },
+  { "ThreadLocalVariablePointers"    , 0x14 },
+  { "ThreadLocalInitFunctionPointers", 0x15 }
+};
+
+static const EnumEntry<unsigned> MachOSectionAttributes[] = {
+  { "LocReloc"         , 1 <<  0 /*S_ATTR_LOC_RELOC          */ },
+  { "ExtReloc"         , 1 <<  1 /*S_ATTR_EXT_RELOC          */ },
+  { "SomeInstructions" , 1 <<  2 /*S_ATTR_SOME_INSTRUCTIONS  */ },
+  { "Debug"            , 1 << 17 /*S_ATTR_DEBUG              */ },
+  { "SelfModifyingCode", 1 << 18 /*S_ATTR_SELF_MODIFYING_CODE*/ },
+  { "LiveSupport"      , 1 << 19 /*S_ATTR_LIVE_SUPPORT       */ },
+  { "NoDeadStrip"      , 1 << 20 /*S_ATTR_NO_DEAD_STRIP      */ },
+  { "StripStaticSyms"  , 1 << 21 /*S_ATTR_STRIP_STATIC_SYMS  */ },
+  { "NoTOC"            , 1 << 22 /*S_ATTR_NO_TOC             */ },
+  { "PureInstructions" , 1 << 23 /*S_ATTR_PURE_INSTRUCTIONS  */ },
+};
+
+static const EnumEntry<unsigned> MachOSymbolRefTypes[] = {
+  { "UndefinedNonLazy",                     0 },
+  { "ReferenceFlagUndefinedLazy",           1 },
+  { "ReferenceFlagDefined",                 2 },
+  { "ReferenceFlagPrivateDefined",          3 },
+  { "ReferenceFlagPrivateUndefinedNonLazy", 4 },
+  { "ReferenceFlagPrivateUndefinedLazy",    5 }
+};
+
+static const EnumEntry<unsigned> MachOSymbolFlags[] = {
+  { "ReferencedDynamically", 0x10 },
+  { "NoDeadStrip",           0x20 },
+  { "WeakRef",               0x40 },
+  { "WeakDef",               0x80 }
+};
+
+static const EnumEntry<unsigned> MachOSymbolTypes[] = {
+  { "Undef",           0x0 },
+  { "External",        0x1 },
+  { "Abs",             0x2 },
+  { "Indirect",        0xA },
+  { "PreboundUndef",   0xC },
+  { "Section",         0xE },
+  { "PrivateExternal", 0x10 }
+};
+
+namespace {
+  enum {
+    N_STAB = 0xE0
+  };
+
+  struct MachOSection {
+    ArrayRef<char> Name;
+    ArrayRef<char> SegmentName;
+    uint64_t Address;
+    uint64_t Size;
+    uint32_t Offset;
+    uint32_t Alignment;
+    uint32_t RelocationTableOffset;
+    uint32_t NumRelocationTableEntries;
+    uint32_t Flags;
+    uint32_t Reserved1;
+    uint32_t Reserved2;
+  };
+
+  struct MachOSymbol {
+    uint32_t StringIndex;
+    uint8_t Type;
+    uint8_t SectionIndex;
+    uint16_t Flags;
+    uint64_t Value;
+  };
+}
+
+static StringRef parseSegmentOrSectionName(ArrayRef<char> P) {
+  if (P[15] == 0)
+    // Null terminated.
+    return StringRef(P.data());
+  // Not null terminated, so this is a 16 char string.
+  return StringRef(P.data(), 16);
+}
+
+static bool is64BitLoadCommand(const MachOObject *MachOObj, DataRefImpl DRI) {
+  LoadCommandInfo LCI = MachOObj->getLoadCommandInfo(DRI.d.a);
+  if (LCI.Command.Type == macho::LCT_Segment64)
+    return true;
+  assert(LCI.Command.Type == macho::LCT_Segment && "Unexpected Type.");
+  return false;
+}
+
+static void getSection(const MachOObject *MachOObj,
+                       DataRefImpl DRI,
+                       MachOSection &Section) {
+  LoadCommandInfo LCI = MachOObj->getLoadCommandInfo(DRI.d.a);
+  if (is64BitLoadCommand(MachOObj, DRI)) {
+    InMemoryStruct<macho::Section64> Sect;
+    MachOObj->ReadSection64(LCI, DRI.d.b, Sect);
+
+    Section.Name        = ArrayRef<char>(Sect->Name);
+    Section.SegmentName = ArrayRef<char>(Sect->SegmentName);
+    Section.Address     = Sect->Address;
+    Section.Size        = Sect->Size;
+    Section.Offset      = Sect->Offset;
+    Section.Alignment   = Sect->Align;
+    Section.RelocationTableOffset = Sect->RelocationTableOffset;
+    Section.NumRelocationTableEntries = Sect->NumRelocationTableEntries;
+    Section.Flags       = Sect->Flags;
+    Section.Reserved1   = Sect->Reserved1;
+    Section.Reserved2   = Sect->Reserved2;
+  } else {
+    InMemoryStruct<macho::Section> Sect;
+    MachOObj->ReadSection(LCI, DRI.d.b, Sect);
+
+    Section.Name        = Sect->Name;
+    Section.SegmentName = Sect->SegmentName;
+    Section.Address     = Sect->Address;
+    Section.Size        = Sect->Size;
+    Section.Offset      = Sect->Offset;
+    Section.Alignment   = Sect->Align;
+    Section.RelocationTableOffset = Sect->RelocationTableOffset;
+    Section.NumRelocationTableEntries = Sect->NumRelocationTableEntries;
+    Section.Flags       = Sect->Flags;
+    Section.Reserved1   = Sect->Reserved1;
+    Section.Reserved2   = Sect->Reserved2;
+  }
+}
+
+static void getSymbolTableEntry(const MachOObject *MachO,
+                                DataRefImpl DRI,
+                                InMemoryStruct<macho::SymbolTableEntry> &Res) {
+  InMemoryStruct<macho::SymtabLoadCommand> SymtabLoadCmd;
+  LoadCommandInfo LCI = MachO->getLoadCommandInfo(DRI.d.a);
+  MachO->ReadSymtabLoadCommand(LCI, SymtabLoadCmd);
+  MachO->ReadSymbolTableEntry(SymtabLoadCmd->SymbolTableOffset, DRI.d.b, Res);
+}
+
+static void getSymbol64TableEntry(const MachOObject *MachO,
+                                  DataRefImpl DRI,
+                               InMemoryStruct<macho::Symbol64TableEntry> &Res) {
+  InMemoryStruct<macho::SymtabLoadCommand> SymtabLoadCmd;
+  LoadCommandInfo LCI = MachO->getLoadCommandInfo(DRI.d.a);
+  MachO->ReadSymtabLoadCommand(LCI, SymtabLoadCmd);
+  MachO->ReadSymbol64TableEntry(SymtabLoadCmd->SymbolTableOffset, DRI.d.b, Res);
+}
+
+static void getSymbol(const MachOObject *MachOObj,
+                      DataRefImpl DRI,
+                      MachOSymbol &Symbol) {
+  if (MachOObj->is64Bit()) {
+    InMemoryStruct<macho::Symbol64TableEntry> Entry;
+    getSymbol64TableEntry(MachOObj, DRI, Entry);
+    Symbol.StringIndex  = Entry->StringIndex;
+    Symbol.Type         = Entry->Type;
+    Symbol.SectionIndex = Entry->SectionIndex;
+    Symbol.Flags        = Entry->Flags;
+    Symbol.Value        = Entry->Value;
+  } else {
+    InMemoryStruct<macho::SymbolTableEntry> Entry;
+    getSymbolTableEntry(MachOObj, DRI, Entry);
+    Symbol.StringIndex  = Entry->StringIndex;
+    Symbol.Type         = Entry->Type;
+    Symbol.SectionIndex = Entry->SectionIndex;
+    Symbol.Flags        = Entry->Flags;
+    Symbol.Value        = Entry->Value;
+  }
+}
+
+void MachODumper::printFileHeaders() {
+  W.startLine() << "FileHeaders not implemented.\n";
+}
+
+void MachODumper::printSections() {
+  ListScope Group(W, "Sections");
+
+  int SectionIndex = -1;
+  error_code EC;
+  for (section_iterator SecI = Obj->begin_sections(),
+                        SecE = Obj->end_sections();
+                        SecI != SecE; SecI.increment(EC)) {
+    if (error(EC)) break;
+
+    ++SectionIndex;
+
+    const MachOObject *MachO = const_cast<MachOObjectFile*>(Obj)->getObject();
+
+    MachOSection Section;
+    getSection(MachO, SecI->getRawDataRefImpl(), Section);
+    StringRef Name;
+    if (error(SecI->getName(Name)))
+        Name = "";
+
+    DictScope SectionD(W, "Section");
+    W.printNumber("Index", SectionIndex);
+    W.printBinary("Name", Name, Section.Name);
+    W.printBinary("Segment", parseSegmentOrSectionName(Section.SegmentName),
+                    Section.SegmentName);
+    W.printHex   ("Address", Section.Address);
+    W.printHex   ("Size", Section.Size);
+    W.printNumber("Offset", Section.Offset);
+    W.printNumber("Alignment", Section.Alignment);
+    W.printHex   ("RelocationOffset", Section.RelocationTableOffset);
+    W.printNumber("RelocationCount", Section.NumRelocationTableEntries);
+    W.printEnum  ("Type", Section.Flags & 0xFF,
+                  makeArrayRef(MachOSectionAttributes));
+    W.printFlags ("Attributes", Section.Flags >> 8,
+                  makeArrayRef(MachOSectionAttributes));
+    W.printHex   ("Reserved1", Section.Reserved1);
+    W.printHex   ("Reserved2", Section.Reserved2);
+
+    if (opts::SectionRelocations) {
+      ListScope D(W, "Relocations");
+      for (relocation_iterator RelI = SecI->begin_relocations(),
+                               RelE = SecI->end_relocations();
+                               RelI != RelE; RelI.increment(EC)) {
+        if (error(EC)) break;
+
+        printRelocation(SecI, RelI);
+      }
+    }
+
+    if (opts::SectionSymbols) {
+      ListScope D(W, "Symbols");
+      for (symbol_iterator SymI = Obj->begin_symbols(),
+                           SymE = Obj->end_symbols();
+                           SymI != SymE; SymI.increment(EC)) {
+        if (error(EC)) break;
+
+        bool Contained = false;
+        if (SecI->containsSymbol(*SymI, Contained) || !Contained)
+          continue;
+
+        printSymbol(SymI);
+      }
+    }
+
+    if (opts::SectionData) {
+      StringRef Data;
+      if (error(SecI->getContents(Data))) break;
+
+      W.printBinaryBlock("SectionData", Data);
+    }
+  }
+}
+
+void MachODumper::printRelocations() {
+  ListScope D(W, "Relocations");
+
+  error_code EC;
+  for (section_iterator SecI = Obj->begin_sections(),
+                        SecE = Obj->end_sections();
+                        SecI != SecE; SecI.increment(EC)) {
+    if (error(EC)) break;
+
+    StringRef Name;
+    if (error(SecI->getName(Name)))
+      continue;
+
+    bool PrintedGroup = false;
+    for (relocation_iterator RelI = SecI->begin_relocations(),
+                             RelE = SecI->end_relocations();
+                             RelI != RelE; RelI.increment(EC)) {
+      if (error(EC)) break;
+
+      if (!PrintedGroup) {
+        W.startLine() << "Section " << Name << " {\n";
+        W.indent();
+        PrintedGroup = true;
+      }
+
+      printRelocation(SecI, RelI);
+    }
+
+    if (PrintedGroup) {
+      W.unindent();
+      W.startLine() << "}\n";
+    }
+  }
+}
+
+void MachODumper::printRelocation(section_iterator SecI,
+                                  relocation_iterator RelI) {
+  uint64_t Offset;
+  SmallString<32> RelocName;
+  int64_t Info;
+  StringRef SymbolName;
+  SymbolRef Symbol;
+  if (error(RelI->getOffset(Offset))) return;
+  if (error(RelI->getTypeName(RelocName))) return;
+  if (error(RelI->getAdditionalInfo(Info))) return;
+  if (error(RelI->getSymbol(Symbol))) return;
+  if (error(Symbol.getName(SymbolName))) return;
+
+  raw_ostream& OS = W.startLine();
+  OS << W.hex(Offset)
+     << " " << RelocName
+     << " " << (SymbolName.size() > 0 ? SymbolName : "-")
+     << " " << W.hex(Info)
+     << "\n";
+}
+
+void MachODumper::printSymbols() {
+  ListScope Group(W, "Symbols");
+
+  error_code EC;
+  for (symbol_iterator SymI = Obj->begin_symbols(),
+                       SymE = Obj->end_symbols();
+                       SymI != SymE; SymI.increment(EC)) {
+    if (error(EC)) break;
+
+    printSymbol(SymI);
+  }
+}
+
+void MachODumper::printDynamicSymbols() {
+  ListScope Group(W, "DynamicSymbols");
+}
+
+void MachODumper::printSymbol(symbol_iterator SymI) {
+  error_code EC;
+
+  StringRef SymbolName;
+  if (SymI->getName(SymbolName))
+    SymbolName = "";
+
+  const MachOObject *MachO = const_cast<MachOObjectFile*>(Obj)->getObject();
+
+  MachOSymbol Symbol;
+  getSymbol(MachO, SymI->getRawDataRefImpl(), Symbol);
+
+  StringRef SectionName;
+  section_iterator SecI(Obj->end_sections());
+  if (error(SymI->getSection(SecI)) ||
+      error(SecI->getName(SectionName)))
+    SectionName = "";
+
+  DictScope D(W, "Symbol");
+  W.printNumber("Name", SymbolName, Symbol.StringIndex);
+  if (Symbol.Type & N_STAB) {
+    W.printHex ("Type", "SymDebugTable", Symbol.Type);
+  } else {
+    W.printEnum("Type", Symbol.Type, makeArrayRef(MachOSymbolTypes));
+  }
+  W.printHex   ("Section", SectionName, Symbol.SectionIndex);
+  W.printEnum  ("RefType", static_cast<uint16_t>(Symbol.Flags & 0xF),
+                  makeArrayRef(MachOSymbolRefTypes));
+  W.printFlags ("Flags", static_cast<uint16_t>(Symbol.Flags & ~0xF),
+                  makeArrayRef(MachOSymbolFlags));
+  W.printHex   ("Value", Symbol.Value);
+}
+
+void MachODumper::printUnwindInfo() {
+  W.startLine() << "UnwindInfo not implemented.\n";
+}