llvm-project/llvm/tools/llvm-readobj/llvm-readobj.cpp

//===- llvm-readobj.cpp - Dump contents of an Object File -----------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This program is a utility that works like traditional Unix "readelf",
// except that it can handle any type of object file recognized by lib/Object.
//
// It makes use of the generic ObjectFile interface.
//
// Caution: This utility is new, experimental, unsupported, and incomplete.
//
//===----------------------------------------------------------------------===//

#include "llvm/ADT/Triple.h"
#include "llvm/Analysis/Verifier.h"
#include "llvm/Object/ELF.h"
#include "llvm/Object/ObjectFile.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/FormattedStream.h"
#include "llvm/Support/PrettyStackTrace.h"
#include "llvm/Support/Signals.h"

using namespace llvm;
using namespace llvm::object;

static cl::opt<std::string>
InputFilename(cl::Positional, cl::desc("<input object>"), cl::init(""));

static const char *getTypeStr(SymbolRef::Type Type) {
  switch (Type) {
  case SymbolRef::ST_Unknown: return "?";
  case SymbolRef::ST_Data: return "DATA";
  case SymbolRef::ST_Debug: return "DBG";
  case SymbolRef::ST_File: return "FILE";
  case SymbolRef::ST_Function: return "FUNC";
  case SymbolRef::ST_Other: return "-";
  }
  return "INV";
}

static std::string getSymbolFlagStr(uint32_t Flags) {
  std::string result;
  if (Flags & SymbolRef::SF_Undefined)
    result += "undef,";
  if (Flags & SymbolRef::SF_Global)
    result += "global,";
  if (Flags & SymbolRef::SF_Weak)
    result += "weak,";
  if (Flags & SymbolRef::SF_Absolute)
    result += "absolute,";
  if (Flags & SymbolRef::SF_ThreadLocal)
    result += "threadlocal,";
  if (Flags & SymbolRef::SF_Common)
    result += "common,";
  if (Flags & SymbolRef::SF_FormatSpecific)
    result += "formatspecific,";

  // Remove trailing comma
  if (result.size() > 0) {
    result.erase(result.size() - 1);
  }
  return result;
}

static void checkError(error_code ec, const char *msg) {
  if (ec)
    report_fatal_error(std::string(msg) + ": " + ec.message());
}

static void
dumpSymbol(const SymbolRef &Sym, const ObjectFile *obj, bool IsDynamic) {
  StringRef Name;
  SymbolRef::Type Type;
  uint32_t Flags;
  uint64_t Address;
  uint64_t Size;
  uint64_t FileOffset;
  checkError(Sym.getName(Name), "SymbolRef.getName() failed");
  checkError(Sym.getAddress(Address), "SymbolRef.getAddress() failed");
  checkError(Sym.getSize(Size), "SymbolRef.getSize() failed");
  checkError(Sym.getFileOffset(FileOffset),
             "SymbolRef.getFileOffset() failed");
  checkError(Sym.getType(Type), "SymbolRef.getType() failed");
  checkError(Sym.getFlags(Flags), "SymbolRef.getFlags() failed");
  std::string FullName = Name;

  // If this is a dynamic symbol from an ELF object, append
  // the symbol's version to the name.
  if (IsDynamic && obj->isELF()) {
    StringRef Version;
    bool IsDefault;
    GetELFSymbolVersion(obj, Sym, Version, IsDefault);
    if (!Version.empty()) {
      FullName += (IsDefault ? "@@" : "@");
      FullName += Version;
    }
  }

  // format() can't handle StringRefs
  outs() << format("  %-32s", FullName.c_str())
         << format("  %-4s", getTypeStr(Type))
         << format("  %16" PRIx64, Address)
         << format("  %16" PRIx64, Size)
         << format("  %16" PRIx64, FileOffset)
         << "  " << getSymbolFlagStr(Flags)
         << "\n";
}

// Iterate through the normal symbols in the ObjectFile
static void dumpSymbols(const ObjectFile *obj) {
  error_code ec;
  uint32_t count = 0;
  outs() << "Symbols:\n";
  symbol_iterator it = obj->begin_symbols();
  symbol_iterator ie = obj->end_symbols();
  while (it != ie) {
    dumpSymbol(*it, obj, false);
    it.increment(ec);
    if (ec)
      report_fatal_error("Symbol iteration failed");
    ++count;
  }
  outs() << "  Total: " << count << "\n\n";
}

// Iterate through the dynamic symbols in the ObjectFile.
static void dumpDynamicSymbols(const ObjectFile *obj) {
  error_code ec;
  uint32_t count = 0;
  outs() << "Dynamic Symbols:\n";
  symbol_iterator it = obj->begin_dynamic_symbols();
  symbol_iterator ie = obj->end_dynamic_symbols();
  while (it != ie) {
    dumpSymbol(*it, obj, true);
    it.increment(ec);
    if (ec)
      report_fatal_error("Symbol iteration failed");
    ++count;
  }
  outs() << "  Total: " << count << "\n\n";
}

static void dumpLibrary(const LibraryRef &lib) {
  StringRef path;
  lib.getPath(path);
  outs() << "  " << path << "\n";
}

// Iterate through needed libraries
static void dumpLibrariesNeeded(const ObjectFile *obj) {
  error_code ec;
  uint32_t count = 0;
  library_iterator it = obj->begin_libraries_needed();
  library_iterator ie = obj->end_libraries_needed();
  outs() << "Libraries needed:\n";
  while (it != ie) {
    dumpLibrary(*it);
    it.increment(ec);
    if (ec)
      report_fatal_error("Needed libraries iteration failed");
    ++count;
  }
  outs() << "  Total: " << count << "\n\n";
}

static void dumpHeaders(const ObjectFile *obj) {
  outs() << "File Format : " << obj->getFileFormatName() << "\n";
  outs() << "Arch        : "
         << Triple::getArchTypeName((llvm::Triple::ArchType)obj->getArch())
         << "\n";
  outs() << "Address Size: " << (8*obj->getBytesInAddress()) << " bits\n";
  outs() << "Load Name   : " << obj->getLoadName() << "\n";
  outs() << "\n";
}

int main(int argc, char** argv) {
  error_code ec;
  sys::PrintStackTraceOnErrorSignal();
  PrettyStackTraceProgram X(argc, argv);

  cl::ParseCommandLineOptions(argc, argv,
                              "LLVM Object Reader\n");

  if (InputFilename.empty()) {
    errs() << "Please specify an input filename\n";
    return 1;
  }

  // Open the object file
  OwningPtr<MemoryBuffer> File;
  if (MemoryBuffer::getFile(InputFilename, File)) {
    errs() << InputFilename << ": Open failed\n";
    return 1;
  }

  ObjectFile *obj = ObjectFile::createObjectFile(File.take());
  if (!obj) {
    errs() << InputFilename << ": Object type not recognized\n";
  }

  dumpHeaders(obj);
  dumpSymbols(obj);
  dumpDynamicSymbols(obj);
  dumpLibrariesNeeded(obj);
  return 0;
}