path: root/utils/yaml2obj/yaml2obj.cpp

//===- yaml2obj - Convert YAML to a binary 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 takes a YAML description of an object file and outputs the
// binary equivalent.
//
// This is used for writing tests that require binary files.
//
//===----------------------------------------------------------------------===//

#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/Support/COFF.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Endian.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/PrettyStackTrace.h"
#include "llvm/Support/Signals.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/YAMLParser.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/system_error.h"
#include <vector>

using namespace llvm;

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

template<class T>
typename llvm::enable_if_c<std::numeric_limits<T>::is_integer, bool>::type
getAs(const llvm::yaml::ScalarNode *SN, T &Result) {
  SmallString<4> Storage;
  StringRef Value = SN->getValue(Storage);
  if (Value.getAsInteger(0, Result))
    return false;
  return true;
}

// Given a container with begin and end with ::value_type of a character type.
// Iterate through pairs of characters in the the set of [a-fA-F0-9] ignoring
// all other characters.
struct hex_pair_iterator {
  StringRef::const_iterator Current, End;
  typedef SmallVector<char, 2> value_type;
  value_type Pair;
  bool IsDone;

  hex_pair_iterator(StringRef C)
    : Current(C.begin()), End(C.end()), IsDone(false) {
    // Initalize Pair.
    ++*this;
  }

  // End iterator.
  hex_pair_iterator() : Current(), End(), IsDone(true) {}

  value_type operator *() const {
    return Pair;
  }

  hex_pair_iterator operator ++() {
    // We're at the end of the input.
    if (Current == End) {
      IsDone = true;
      return *this;
    }
    Pair = value_type();
    for (; Current != End && Pair.size() != 2; ++Current) {
      // Is a valid hex digit.
      if ((*Current >= '0' && *Current <= '9') ||
          (*Current >= 'a' && *Current <= 'f') ||
          (*Current >= 'A' && *Current <= 'F'))
        Pair.push_back(*Current);
    }
    // Hit the end without getting 2 hex digits. Pair is invalid.
    if (Pair.size() != 2)
      IsDone = true;
    return *this;
  }

  bool operator ==(const hex_pair_iterator Other) {
    return (IsDone == Other.IsDone) ||
           (Current == Other.Current && End == Other.End);
  }

  bool operator !=(const hex_pair_iterator Other) {
    return !(*this == Other);
  }
};

template <class ContainerOut>
static bool hexStringToByteArray(StringRef Str, ContainerOut &Out) {
  for (hex_pair_iterator I(Str), E; I != E; ++I) {
    typename hex_pair_iterator::value_type Pair = *I;
    typename ContainerOut::value_type Byte;
    if (StringRef(Pair.data(), 2).getAsInteger(16, Byte))
      return false;
    Out.push_back(Byte);
  }
  return true;
}

/// This parses a yaml stream that represents a COFF object file.
/// See docs/yaml2obj for the yaml scheema.
struct COFFParser {
  COFFParser(yaml::Stream &Input) : YS(Input) {
    std::memset(&Header, 0, sizeof(Header));
    // A COFF string table always starts with a 4 byte size field. Offsets into
    // it include this size, so allocate it now.
    StringTable.append(4, 0);
  }

  bool parseHeader(yaml::Node *HeaderN) {
    yaml::MappingNode *MN = dyn_cast<yaml::MappingNode>(HeaderN);
    if (!MN) {
      YS.printError(HeaderN, "header's value must be a mapping node");
      return false;
    }
    for (yaml::MappingNode::iterator i = MN->begin(), e = MN->end();
                                     i != e; ++i) {
      yaml::ScalarNode *Key = dyn_cast<yaml::ScalarNode>(i->getKey());
      if (!Key) {
        YS.printError(i->getKey(), "Keys must be scalar values");
        return false;
      }
      SmallString<32> Storage;
      StringRef KeyValue = Key->getValue(Storage);
      if (KeyValue == "Characteristics") {
        if (!parseHeaderCharacteristics(i-></