Add yaml2obj. A utility to convert YAML to binaries.

yaml2obj takes a textual description of an object file in YAML format
and outputs the binary equivalent. This greatly simplifies writing
tests that take binary object files as input.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161205 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 879 insertions, 0 deletions

diff --git a/utils/yaml2obj/yaml2obj.cpp b/utils/yaml2obj/yaml2obj.cpp
new file mode 100644
index 0000000000..d21336f5fd
--- /dev/null
+++ b/utils/yaml2obj/yaml2obj.cpp
@@ -0,0 +1,879 @@
+//===- 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/raw_ostream.h"
+#include "llvm/Support/Signals.h"
+#include "llvm/Support/SourceMgr.h"
+#include "llvm/Support/system_error.h"
+#include "llvm/Support/YAMLParser.h"
+
+#include <vector>
+
+using namespace llvm;
+
+static cl::opt<std::string>
+  Input(cl::Positional, cl::desc("<input>"), cl::init("-"));
+
+template<class T>
+typename std::enable_if<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 == true) ||
+           (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->getValue()))
+          return false;
+      } else {
+        yaml::ScalarNode *Value = dyn_cast<yaml::ScalarNode>(i->getValue());
+        if (!Value) {
+          YS.printError(Value,
+            Twine(KeyValue) + " must be a scalar value");
+          return false;
+        }
+        if (KeyValue == "Machine") {
+          uint16_t Machine;
+          if (!getAs(Value, Machine)) {
+            // It's not a raw number, try matching the string.
+            StringRef ValueValue = Value->getValue(Storage);
+            Machine = StringSwitch<COFF::MachineTypes>(ValueValue)
+              .Case( "IMAGE_FILE_MACHINE_UNKNOWN"
+                   , COFF::IMAGE_FILE_MACHINE_UNKNOWN)
+              .Case( "IMAGE_FILE_MACHINE_AM33"
+                   , COFF::IMAGE_FILE_MACHINE_AM33)
+              .Case( "IMAGE_FILE_MACHINE_AMD64"
+                   , COFF::IMAGE_FILE_MACHINE_AMD64)
+              .Case( "IMAGE_FILE_MACHINE_ARM"
+                   , COFF::IMAGE_FILE_MACHINE_ARM)
+              .Case( "IMAGE_FILE_MACHINE_ARMV7"
+                   , COFF::IMAGE_FILE_MACHINE_ARMV7)
+              .Case( "IMAGE_FILE_MACHINE_EBC"
+                   , COFF::IMAGE_FILE_MACHINE_EBC)
+              .Case( "IMAGE_FILE_MACHINE_I386"
+                   , COFF::IMAGE_FILE_MACHINE_I386)
+              .Case( "IMAGE_FILE_MACHINE_IA64"
+                   , COFF::IMAGE_FILE_MACHINE_IA64)
+              .Case( "IMAGE_FILE_MACHINE_M32R"
+                   , COFF::IMAGE_FILE_MACHINE_M32R)
+              .Case( "IMAGE_FILE_MACHINE_MIPS16"
+                   , COFF::IMAGE_FILE_MACHINE_MIPS16)
+              .Case( "IMAGE_FILE_MACHINE_MIPSFPU"
+                   , COFF::IMAGE_FILE_MACHINE_MIPSFPU)
+              .Case( "IMAGE_FILE_MACHINE_MIPSFPU16"
+                   , COFF::IMAGE_FILE_MACHINE_MIPSFPU16)
+              .Case( "IMAGE_FILE_MACHINE_POWERPC"
+                   , COFF::IMAGE_FILE_MACHINE_POWERPC)
+              .Case( "IMAGE_FILE_MACHINE_POWERPCFP"
+                   , COFF::IMAGE_FILE_MACHINE_POWERPCFP)
+              .Case( "IMAGE_FILE_MACHINE_R4000"
+                   , COFF::IMAGE_FILE_MACHINE_R4000)
+              .Case( "IMAGE_FILE_MACHINE_SH3"
+                   , COFF::IMAGE_FILE_MACHINE_SH3)
+              .Case( "IMAGE_FILE_MACHINE_SH3DSP"
+                   , COFF::IMAGE_FILE_MACHINE_SH3DSP)
+              .Case( "IMAGE_FILE_MACHINE_SH4"
+                   , COFF::IMAGE_FILE_MACHINE_SH4)
+              .Case( "IMAGE_FILE_MACHINE_SH5"
+                   , COFF::IMAGE_FILE_MACHINE_SH5)
+              .Case( "IMAGE_FILE_MACHINE_THUMB"
+                   , COFF::IMAGE_FILE_MACHINE_THUMB)
+              .Case( "IMAGE_FILE_MACHINE_WCEMIPSV2"
+                   , COFF::IMAGE_FILE_MACHINE_WCEMIPSV2)
+              .Default(COFF::MT_Invalid);
+            if (Machine == COFF::MT_Invalid) {
+              YS.printError(Value, "Invalid value for Machine");
+              return false;
+            }
+          }
+          Header.Machine = Machine;
+        } else if (KeyValue == "NumberOfSections") {
+          if (!getAs(Value, Header.NumberOfSections)) {
+              YS.printError(Value, "Invalid value for NumberOfSections");
+              return false;
+          }
+        } else if (KeyValue == "TimeDateStamp") {
+          if (!getAs(Value, Header.TimeDateStamp)) {
+              YS.printError(Value, "Invalid value for TimeDateStamp");
+              return false;
+          }
+        } else if (KeyValue == "PointerToSymbolTable") {
+          if (!getAs(Value, Header.PointerToSymbolTable)) {
+              YS.printError(Value, "Invalid value for PointerToSymbolTable");
+              return false;
+          }
+        } else if (KeyValue == "NumberOfSymbols") {
+          if (!getAs(Value, Header.NumberOfSymbols)) {
+              YS.printError(Value, "Invalid value for NumberOfSymbols");
+              return false;
+          }
+        } else if (KeyValue == "SizeOfOptionalHeader") {
+          if (!getAs(Value, Header.SizeOfOptionalHeader)) {
+              YS.printError(Value, "Invalid value for SizeOfOptionalHeader");
+              return false;
+          }
+        } else {
+          YS.printError(Key, "Unrecognized key in header");
+          return false;
+        }
+      }
+    }
+    return true;
+  }
+
+  bool parseHeaderCharacteristics(yaml::Node *Characteristics) {
+    yaml::ScalarNode *Value = dyn_cast<yaml::ScalarNode>(Characteristics);
+    yaml::SequenceNode *SeqValue
+      = dyn_cast<yaml::SequenceNode>(Characteristics);
+    if (!Value && !SeqValue) {
+      YS.printError(Characteristics,
+        "Characteristics must either be a number or sequence");
+      return false;
+    }
+    if (Value) {
+      if (!getAs(Value, Header.Characteristics)) {
+        YS.printError(Value, "Invalid value for Characteristics");
+        return false;
+      }
+    } else {
+      for (yaml::SequenceNode::iterator ci = SeqValue->begin(),
+                                        ce = SeqValue->end();
+                                        ci != ce; ++ci) {
+        yaml::ScalarNode *CharValue = dyn_cast<yaml::ScalarNode>(&*ci);
+        if (!CharValue) {
+          YS.printError(CharValue,
+            "Characteristics must be scalar values");
+          return false;
+        }
+        SmallString<32> Storage;
+        StringRef Char = CharValue->getValue(Storage);
+        uint16_t Characteristic = StringSwitch<COFF::Characteristics>(Char)
+          .Case( "IMAGE_FILE_RELOCS_STRIPPED"
+                , COFF::IMAGE_FILE_RELOCS_STRIPPED)
+          .Case( "IMAGE_FILE_EXECUTABLE_IMAGE"
+                , COFF::IMAGE_FILE_EXECUTABLE_IMAGE)
+          .Case( "IMAGE_FILE_LINE_NUMS_STRIPPED"
+                , COFF::IMAGE_FILE_LINE_NUMS_STRIPPED)
+          .Case( "IMAGE_FILE_LOCAL_SYMS_STRIPPED"
+                , COFF::IMAGE_FILE_LOCAL_SYMS_STRIPPED)
+          .Case( "IMAGE_FILE_AGGRESSIVE_WS_TRIM"
+                , COFF::IMAGE_FILE_AGGRESSIVE_WS_TRIM)
+          .Case( "IMAGE_FILE_LARGE_ADDRESS_AWARE"
+                , COFF::IMAGE_FILE_LARGE_ADDRESS_AWARE)
+          .Case( "IMAGE_FILE_BYTES_REVERSED_LO"
+                , COFF::IMAGE_FILE_BYTES_REVERSED_LO)
+          .Case( "IMAGE_FILE_32BIT_MACHINE"
+                , COFF::IMAGE_FILE_32BIT_MACHINE)
+          .Case( "IMAGE_FILE_DEBUG_STRIPPED"
+                , COFF::IMAGE_FILE_DEBUG_STRIPPED)
+          .Case( "IMAGE_FILE_REMOVABLE_RUN_FROM_SWAP"
+                , COFF::IMAGE_FILE_REMOVABLE_RUN_FROM_SWAP)
+          .Case( "IMAGE_FILE_SYSTEM"
+                , COFF::IMAGE_FILE_SYSTEM)
+          .Case( "IMAGE_FILE_DLL"
+                , COFF::IMAGE_FILE_DLL)
+          .Case( "IMAGE_FILE_UP_SYSTEM_ONLY"
+                , COFF::IMAGE_FILE_UP_SYSTEM_ONLY)
+          .Default(COFF::C_Invalid);
+        if (Characteristic == COFF::C_Invalid) {
+          // TODO: Typo-correct.
+          YS.printError(CharValue,
+            "Invalid value for Characteristic");
+          return false;
+        }
+        Header.Characteristics |= Characteristic;
+      }
+    }
+    return true;
+  }
+
+  bool parseSections(yaml::Node *SectionsN) {
+    yaml::SequenceNode *SN = dyn_cast<yaml::SequenceNode>(SectionsN);
+    if (!SN) {
+      YS.printError(SectionsN, "Sections must be a sequence");
+      return false;
+    }
+    for (yaml::SequenceNode::iterator i = SN->begin(), e = SN->end();
+                                      i != e; ++i) {
+      Section Sec;
+      std::memset(&Sec.Header, 0, sizeof(Sec.Header));
+      yaml::MappingNode *SecMap = dyn_cast<yaml::MappingNode>(&*i);
+      if (!SecMap) {
+        YS.printError(&*i, "Section entry must be a map");
+        return false;
+      }
+      for (yaml::MappingNode::iterator si = SecMap->begin(), se = SecMap->end();
+                                       si != se; ++si) {
+        yaml::ScalarNode *Key = dyn_cast<yaml::ScalarNode>(si->getKey());
+        if (!Key) {
+          YS.printError(si->getKey(), "Keys must be scalar values");
+          return false;
+        }
+        SmallString<32> Storage;
+        StringRef KeyValue = Key->getValue(Storage);
+
+        yaml::ScalarNode *Value = dyn_cast<yaml::ScalarNode>(si->getValue());
+        if (KeyValue == "Name") {
+          // If the name is less than 8 bytes, store it in place, otherwise
+          // store it in the string table.
+          StringRef Name = Value->getValue(Storage);
+          std::fill_n(Sec.Header.Name, unsigned(COFF::NameSize), 0);
+          if (Name.size() <= COFF::NameSize) {
+            std::copy(Name.begin(), Name.end(), Sec.Header.Name);
+          } else {
+            // Add string to the string table and format the index for output.
+            unsigned Index = getStringIndex(Name);
+            std::string str = utostr(Index);
+            if (str.size() > 7) {
+              YS.printError(Value, "String table got too large");
+              return false;
+            }
+            Sec.Header.Name[0] = '/';
+            std::copy(str.begin(), str.end(), Sec.Header.Name + 1);
+          }
+        } else if (KeyValue == "VirtualSize") {
+          if (!getAs(Value, Sec.Header.VirtualSize)) {
+            YS.printError(Value, "Invalid value for VirtualSize");
+            return false;
+          }
+        } else if (KeyValue == "VirtualAddress") {
+          if (!getAs(Value, Sec.Header.VirtualAddress)) {
+            YS.printError(Value, "Invalid value for VirtualAddress");
+            return false;
+          }
+        } else if (KeyValue == "SizeOfRawData") {
+          if (!getAs(Value, Sec.Header.SizeOfRawData)) {
+            YS.printError(Value, "Invalid value for SizeOfRawData");
+            return false;
+          }
+        } else if (KeyValue == "PointerToRawData") {
+          if (!getAs(Value, Sec.Header.PointerToRawData)) {
+            YS.printError(Value, "Invalid value for PointerToRawData");
+            return false;
+          }
+        } else if (KeyValue == "PointerToRelocations") {
+          if (!getAs(Value, Sec.Header.PointerToRelocations)) {
+            YS.printError(Value, "Invalid value for PointerToRelocations");
+            return false;
+          }
+        } else if (KeyValue == "PointerToLineNumbers") {
+          if (!getAs(Value, Sec.Header.PointerToLineNumbers)) {
+            YS.printError(Value, "Invalid value for PointerToLineNumbers");
+            return false;
+          }
+        } else if (KeyValue == "NumberOfRelocations") {
+          if (!getAs(Value, Sec.Header.NumberOfRelocations)) {
+            YS.printError(Value, "Invalid value for NumberOfRelocations");
+            return false;
+          }
+        } else if (KeyValue == "NumberOfLineNumbers") {
+          if (!getAs(Value, Sec.Header.NumberOfLineNumbers)) {
+            YS.printError(Value, "Invalid value for NumberOfLineNumbers");
+            return false;
+          }
+        } else if (KeyValue == "Characteristics") {
+          yaml::SequenceNode *SeqValue
+            = dyn_cast<yaml::SequenceNode>(si->getValue());
+          if (!Value && !SeqValue) {
+            YS.printError(si->getValue(),
+              "Characteristics must either be a number or sequence");
+            return false;
+          }
+          if (Value) {
+            if (!getAs(Value, Sec.Header.Characteristics)) {
+              YS.printError(Value, "Invalid value for Characteristics");
+              return false;
+            }
+          } else {
+            for (yaml::SequenceNode::iterator ci = SeqValue->begin(),
+                                              ce = SeqValue->end();
+                                              ci != ce; ++ci) {
+              yaml::ScalarNode *CharValue = dyn_cast<yaml::ScalarNode>(&*ci);
+              if (!CharValue) {
+                YS.printError(CharValue, "Invalid value for Characteristics");
+                return false;
+              }
+              StringRef Char = CharValue->getValue(Storage);
+              uint32_t Characteristic =
+                StringSwitch<COFF::SectionCharacteristics>(Char)
+                .Case( "IMAGE_SCN_TYPE_NO_PAD"
+                     , COFF::IMAGE_SCN_TYPE_NO_PAD)
+                .Case( "IMAGE_SCN_CNT_CODE"
+                     , COFF::IMAGE_SCN_CNT_CODE)
+                .Case( "IMAGE_SCN_CNT_INITIALIZED_DATA"
+                     , COFF::IMAGE_SCN_CNT_INITIALIZED_DATA)
+                .Case( "IMAGE_SCN_CNT_UNINITIALIZED_DATA"
+                     , COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA)
+                .Case( "IMAGE_SCN_LNK_OTHER"
+                     , COFF::IMAGE_SCN_LNK_OTHER)
+                .Case( "IMAGE_SCN_LNK_INFO"
+                     , COFF::IMAGE_SCN_LNK_INFO)
+                .Case( "IMAGE_SCN_LNK_REMOVE"
+                     , COFF::IMAGE_SCN_LNK_REMOVE)
+                .Case( "IMAGE_SCN_LNK_COMDAT"
+                     , COFF::IMAGE_SCN_LNK_COMDAT)
+                .Case( "IMAGE_SCN_GPREL"
+                     , COFF::IMAGE_SCN_GPREL)
+                .Case( "IMAGE_SCN_MEM_PURGEABLE"
+                     , COFF::IMAGE_SCN_MEM_PURGEABLE)
+                .Case( "IMAGE_SCN_MEM_16BIT"
+                     , COFF::IMAGE_SCN_MEM_16BIT)
+                .Case( "IMAGE_SCN_MEM_LOCKED"
+                     , COFF::IMAGE_SCN_MEM_LOCKED)
+                .Case( "IMAGE_SCN_MEM_PRELOAD"
+                     , COFF::IMAGE_SCN_MEM_PRELOAD)
+                .Case( "IMAGE_SCN_ALIGN_1BYTES"
+                     , COFF::IMAGE_SCN_ALIGN_1BYTES)
+                .Case( "IMAGE_SCN_ALIGN_2BYTES"
+                     , COFF::IMAGE_SCN_ALIGN_2BYTES)
+                .Case( "IMAGE_SCN_ALIGN_4BYTES"
+                     , COFF::IMAGE_SCN_ALIGN_4BYTES)
+                .Case( "IMAGE_SCN_ALIGN_8BYTES"
+                     , COFF::IMAGE_SCN_ALIGN_8BYTES)
+                .Case( "IMAGE_SCN_ALIGN_16BYTES"
+                     , COFF::IMAGE_SCN_ALIGN_16BYTES)
+                .Case( "IMAGE_SCN_ALIGN_32BYTES"
+                     , COFF::IMAGE_SCN_ALIGN_32BYTES)
+                .Case( "IMAGE_SCN_ALIGN_64BYTES"
+                     , COFF::IMAGE_SCN_ALIGN_64BYTES)
+                .Case( "IMAGE_SCN_ALIGN_128BYTES"
+                     , COFF::IMAGE_SCN_ALIGN_128BYTES)
+                .Case( "IMAGE_SCN_ALIGN_256BYTES"
+                     , COFF::IMAGE_SCN_ALIGN_256BYTES)
+                .Case( "IMAGE_SCN_ALIGN_512BYTES"
+                     , COFF::IMAGE_SCN_ALIGN_512BYTES)
+                .Case( "IMAGE_SCN_ALIGN_1024BYTES"
+                     , COFF::IMAGE_SCN_ALIGN_1024BYTES)
+                .Case( "IMAGE_SCN_ALIGN_2048BYTES"
+                     , COFF::IMAGE_SCN_ALIGN_2048BYTES)
+                .Case( "IMAGE_SCN_ALIGN_4096BYTES"
+                     , COFF::IMAGE_SCN_ALIGN_4096BYTES)
+                .Case( "IMAGE_SCN_ALIGN_8192BYTES"
+                     , COFF::IMAGE_SCN_ALIGN_8192BYTES)
+                .Case( "IMAGE_SCN_LNK_NRELOC_OVFL"
+                     , COFF::IMAGE_SCN_LNK_NRELOC_OVFL)
+                .Case( "IMAGE_SCN_MEM_DISCARDABLE"
+                     , COFF::IMAGE_SCN_MEM_DISCARDABLE)
+                .Case( "IMAGE_SCN_MEM_NOT_CACHED"
+                     , COFF::IMAGE_SCN_MEM_NOT_CACHED)
+                .Case( "IMAGE_SCN_MEM_NOT_PAGED"
+                     , COFF::IMAGE_SCN_MEM_NOT_PAGED)
+                .Case( "IMAGE_SCN_MEM_SHARED"
+                     , COFF::IMAGE_SCN_MEM_SHARED)
+                .Case( "IMAGE_SCN_MEM_EXECUTE"
+                     , COFF::IMAGE_SCN_MEM_EXECUTE)
+                .Case( "IMAGE_SCN_MEM_READ"
+                     , COFF::IMAGE_SCN_MEM_READ)
+                .Case( "IMAGE_SCN_MEM_WRITE"
+                     , COFF::IMAGE_SCN_MEM_WRITE)
+                .Default(COFF::SC_Invalid);
+              if (Characteristic == COFF::SC_Invalid) {
+                YS.printError(CharValue, "Invalid value for Characteristic");
+                return false;
+              }
+              Sec.Header.Characteristics |= Characteristic;
+            }
+          }
+        } else if (KeyValue == "SectionData") {
+          yaml::ScalarNode *Value = dyn_cast<yaml::ScalarNode>(si->getValue());
+          SmallString<32> Storage;
+          StringRef Data = Value->getValue(Storage);
+          if (!hexStringToByteArray(Data, Sec.Data)) {
+            YS.printError(Value, "SectionData must be a collection of pairs of"
+                                 "hex bytes");
+            return false;
+          }
+        } else
+          si->skip();
+      }
+      Sections.push_back(Sec);
+    }
+    return true;
+  }
+
+  bool parseSymbols(yaml::Node *SymbolsN) {
+    yaml::SequenceNode *SN = dyn_cast<yaml::SequenceNode>(SymbolsN);
+    if (!SN) {
+      YS.printError(SymbolsN, "Symbols must be a sequence");
+      return false;
+    }
+    for (yaml::SequenceNode::iterator i = SN->begin(), e = SN->end();
+                                      i != e; ++i) {
+      Symbol Sym;
+      std::memset(&Sym.Header, 0, sizeof(Sym.Header));
+      yaml::MappingNode *SymMap = dyn_cast<yaml::MappingNode>(&*i);
+      if (!SymMap) {
+        YS.printError(&*i, "Symbol must be a map");
+        return false;
+      }
+      for (yaml::MappingNode::iterator si = SymMap->begin(), se = SymMap->end();
+                                       si != se; ++si) {
+        yaml::ScalarNode *Key = dyn_cast<yaml::ScalarNode>(si->getKey());
+        if (!Key) {
+          YS.printError(si->getKey(), "Keys must be scalar values");
+          return false;
+        }
+        SmallString<32> Storage;
+        StringRef KeyValue = Key->getValue(Storage);
+
+        yaml::ScalarNode *Value = dyn_cast<yaml::ScalarNode>(si->getValue());
+        if (!Value) {
+          YS.printError(si->getValue(), "Must be a scalar value");
+          return false;
+        }
+        if (KeyValue == "Name") {
+          // If the name is less than 8 bytes, store it in place, otherwise
+          // store it in the string table.
+          StringRef Name = Value->getValue(Storage);
+          std::fill_n(Sym.Header.Name, unsigned(COFF::NameSize), 0);
+          if (Name.size() <= COFF::NameSize) {
+            std::copy(Name.begin(), Name.end(), Sym.Header.Name);
+          } else {
+            // Add string to the string table and format the index for output.
+            unsigned Index = getStringIndex(Name);
+            *reinterpret_cast<support::aligned_ulittle32_t*>(
+              Sym.Header.Name + 4) = Index;
+          }
+        } else if (KeyValue == "Value") {
+          if (!getAs(Value, Sym.Header.Value)) {
+            YS.printError(Value, "Invalid value for Value");
+            return false;
+          }
+        } else if (KeyValue == "SimpleType") {
+          Sym.Header.Type |= StringSwitch<COFF::SymbolBaseType>(
+            Value->getValue(Storage))
+            .Case("IMAGE_SYM_TYPE_NULL", COFF::IMAGE_SYM_TYPE_NULL)
+            .Case("IMAGE_SYM_TYPE_VOID", COFF::IMAGE_SYM_TYPE_VOID)
+            .Case("IMAGE_SYM_TYPE_CHAR", COFF::IMAGE_SYM_TYPE_CHAR)
+            .Case("IMAGE_SYM_TYPE_SHORT", COFF::IMAGE_SYM_TYPE_SHORT)
+            .Case("IMAGE_SYM_TYPE_INT", COFF::IMAGE_SYM_TYPE_INT)
+            .Case("IMAGE_SYM_TYPE_LONG", COFF::IMAGE_SYM_TYPE_LONG)
+            .Case("IMAGE_SYM_TYPE_FLOAT", COFF::IMAGE_SYM_TYPE_FLOAT)
+            .Case("IMAGE_SYM_TYPE_DOUBLE", COFF::IMAGE_SYM_TYPE_DOUBLE)
+            .Case("IMAGE_SYM_TYPE_STRUCT", COFF::IMAGE_SYM_TYPE_STRUCT)
+            .Case("IMAGE_SYM_TYPE_UNION", COFF::IMAGE_SYM_TYPE_UNION)
+            .Case("IMAGE_SYM_TYPE_ENUM", COFF::IMAGE_SYM_TYPE_ENUM)
+            .Case("IMAGE_SYM_TYPE_MOE", COFF::IMAGE_SYM_TYPE_MOE)
+            .Case("IMAGE_SYM_TYPE_BYTE", COFF::IMAGE_SYM_TYPE_BYTE)
+            .Case("IMAGE_SYM_TYPE_WORD", COFF::IMAGE_SYM_TYPE_WORD)
+            .Case("IMAGE_SYM_TYPE_UINT", COFF::IMAGE_SYM_TYPE_UINT)
+            .Case("IMAGE_SYM_TYPE_DWORD", COFF::IMAGE_SYM_TYPE_DWORD)
+            .Default(COFF::IMAGE_SYM_TYPE_NULL);
+        } else if (KeyValue == "ComplexType") {
+          Sym.Header.Type |= StringSwitch<COFF::SymbolComplexType>(
+            Value->getValue(Storage))
+            .Case("IMAGE_SYM_DTYPE_NULL", COFF::IMAGE_SYM_DTYPE_NULL)
+            .Case("IMAGE_SYM_DTYPE_POINTER", COFF::IMAGE_SYM_DTYPE_POINTER)
+            .Case("IMAGE_SYM_DTYPE_FUNCTION", COFF::IMAGE_SYM_DTYPE_FUNCTION)
+            .Case("IMAGE_SYM_DTYPE_ARRAY", COFF::IMAGE_SYM_DTYPE_ARRAY)
+            .Default(COFF::IMAGE_SYM_DTYPE_NULL)
+            << COFF::SCT_COMPLEX_TYPE_SHIFT;
+        } else if (KeyValue == "StorageClass") {
+          Sym.Header.StorageClass = StringSwitch<COFF::SymbolStorageClass>(
+            Value->getValue(Storage))
+            .Case( "IMAGE_SYM_CLASS_END_OF_FUNCTION"
+                 , COFF::IMAGE_SYM_CLASS_END_OF_FUNCTION)
+            .Case( "IMAGE_SYM_CLASS_NULL"
+                 , COFF::IMAGE_SYM_CLASS_NULL)
+            .Case( "IMAGE_SYM_CLASS_AUTOMATIC"
+                 , COFF::IMAGE_SYM_CLASS_AUTOMATIC)
+            .Case( "IMAGE_SYM_CLASS_EXTERNAL"
+                 , COFF::IMAGE_SYM_CLASS_EXTERNAL)
+            .Case( "IMAGE_SYM_CLASS_STATIC"
+                 , COFF::IMAGE_SYM_CLASS_STATIC)
+            .Case( "IMAGE_SYM_CLASS_REGISTER"
+                 , COFF::IMAGE_SYM_CLASS_REGISTER)
+            .Case( "IMAGE_SYM_CLASS_EXTERNAL_DEF"
+                 , COFF::IMAGE_SYM_CLASS_EXTERNAL_DEF)
+            .Case( "IMAGE_SYM_CLASS_LABEL"
+                 , COFF::IMAGE_SYM_CLASS_LABEL)
+            .Case( "IMAGE_SYM_CLASS_UNDEFINED_LABEL"
+                 , COFF::IMAGE_SYM_CLASS_UNDEFINED_LABEL)
+            .Case( "IMAGE_SYM_CLASS_MEMBER_OF_STRUCT"
+                 , COFF::IMAGE_SYM_CLASS_MEMBER_OF_STRUCT)
+            .Case( "IMAGE_SYM_CLASS_ARGUMENT"
+                 , COFF::IMAGE_SYM_CLASS_ARGUMENT)
+            .Case( "IMAGE_SYM_CLASS_STRUCT_TAG"
+                 , COFF::IMAGE_SYM_CLASS_STRUCT_TAG)
+            .Case( "IMAGE_SYM_CLASS_MEMBER_OF_UNION"
+                 , COFF::IMAGE_SYM_CLASS_MEMBER_OF_UNION)
+            .Case( "IMAGE_SYM_CLASS_UNION_TAG"
+                 , COFF::IMAGE_SYM_CLASS_UNION_TAG)
+            .Case( "IMAGE_SYM_CLASS_TYPE_DEFINITION"
+                 , COFF::IMAGE_SYM_CLASS_TYPE_DEFINITION)
+            .Case( "IMAGE_SYM_CLASS_UNDEFINED_STATIC"
+                 , COFF::IMAGE_SYM_CLASS_UNDEFINED_STATIC)
+            .Case( "IMAGE_SYM_CLASS_ENUM_TAG"
+                 , COFF::IMAGE_SYM_CLASS_ENUM_TAG)
+            .Case( "IMAGE_SYM_CLASS_MEMBER_OF_ENUM"
+                 , COFF::IMAGE_SYM_CLASS_MEMBER_OF_ENUM)
+            .Case( "IMAGE_SYM_CLASS_REGISTER_PARAM"
+                 , COFF::IMAGE_SYM_CLASS_REGISTER_PARAM)
+            .Case( "IMAGE_SYM_CLASS_BIT_FIELD"
+                 , COFF::IMAGE_SYM_CLASS_BIT_FIELD)
+            .Case( "IMAGE_SYM_CLASS_BLOCK"
+                 , COFF::IMAGE_SYM_CLASS_BLOCK)
+            .Case( "IMAGE_SYM_CLASS_FUNCTION"
+                 , COFF::IMAGE_SYM_CLASS_FUNCTION)
+            .Case( "IMAGE_SYM_CLASS_END_OF_STRUCT"
+                 , COFF::IMAGE_SYM_CLASS_END_OF_STRUCT)
+            .Case( "IMAGE_SYM_CLASS_FILE"
+                 , COFF::IMAGE_SYM_CLASS_FILE)
+            .Case( "IMAGE_SYM_CLASS_SECTION"
+                 , COFF::IMAGE_SYM_CLASS_SECTION)
+            .Case( "IMAGE_SYM_CLASS_WEAK_EXTERNAL"
+                 , COFF::IMAGE_SYM_CLASS_WEAK_EXTERNAL)
+            .Case( "IMAGE_SYM_CLASS_CLR_TOKEN"
+                 , COFF::IMAGE_SYM_CLASS_CLR_TOKEN)
+            .Default(COFF::SSC_Invalid);
+          if (Sym.Header.StorageClass == COFF::SSC_Invalid) {
+            YS.printError(Value, "Invalid value for StorageClass");
+            return false;
+          }
+        } else if (KeyValue == "SectionNumber") {
+          if (!getAs(Value, Sym.Header.SectionNumber)) {
+              YS.printError(Value, "Invalid value for SectionNumber");
+              return false;
+          }
+        } else if (KeyValue == "AuxillaryData") {
+          StringRef Data = Value->getValue(Storage);
+          if (!hexStringToByteArray(Data, Sym.AuxSymbols)) {
+            YS.printError(Value, "AuxillaryData must be a collection of pairs"
+                                 "of hex bytes");
+            return false;
+          }
+        } else
+          si->skip();
+      }
+      Symbols.push_back(Sym);
+    }
+    return true;
+  }
+
+  bool parse() {
+    yaml::Document &D = *YS.begin();
+    yaml::MappingNode *Root = dyn_cast<yaml::MappingNode>(D.getRoot());
+    if (!Root) {
+      YS.printError(D.getRoot(), "Root node must be a map");
+      return false;
+    }
+    for (yaml::MappingNode::iterator i = Root->begin(), e = Root->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 == "header") {
+        if (!parseHeader(i->getValue()))
+          return false;
+      } else if (KeyValue == "sections") {
+        if (!parseSections(i->getValue()))
+          return false;
+      } else if (KeyValue == "symbols") {
+        if (!parseSymbols(i->getValue()))
+          return false;
+      }
+    }
+    return !YS.failed();
+  }
+
+  unsigned getStringIndex(StringRef Str) {
+    StringMap<unsigned>::iterator i = StringTableMap.find(Str);
+    if (i == StringTableMap.end()) {
+      unsigned Index = StringTable.size();
+      StringTable.append(Str.begin(), Str.end());
+      StringTable.push_back(0);
+      StringTableMap[Str] = Index;
+      return Index;
+    }
+    return i->second;
+  }
+
+  yaml::Stream &YS;
+  COFF::header Header;
+
+  struct Section {
+    COFF::section Header;
+    std::vector<uint8_t> Data;
+    std::vector<COFF::relocation> Relocations;
+  };
+
+  struct Symbol {
+    COFF::symbol Header;
+    std::vector<uint8_t> AuxSymbols;
+  };
+
+  std::vector<Section> Sections;
+  std::vector<Symbol> Symbols;
+  StringMap<unsigned> StringTableMap;
+  std::string StringTable;
+};
+
+// Take a CP and assign addresses and sizes to everything. Returns false if the
+// layout is not valid to do.
+static bool layoutCOFF(COFFParser &CP) {
+  uint32_t SectionTableStart = 0;
+  uint32_t SectionTableSize  = 0;
+
+  // The section table starts immediately after the header, including the
+  // optional header.
+  SectionTableStart = sizeof(COFF::header) + CP.Header.SizeOfOptionalHeader;
+  SectionTableSize = sizeof(COFF::section) * CP.Sections.size();
+
+  uint32_t CurrentSectionDataOffset = SectionTableStart + SectionTableSize;
+
+  // Assign each section data address consecutively.
+  for (std::vector<COFFParser::Section>::iterator i = CP.Sections.begin(),
+                                                  e = CP.Sections.end();
+                                                  i != e; ++i) {
+    if (!i->Data.empty()) {
+      i->Header.SizeOfRawData = i->Data.size();
+      i->Header.PointerToRawData = CurrentSectionDataOffset;
+      CurrentSectionDataOffset += i->Header.SizeOfRawData;
+      // TODO: Handle alignment.
+    } else {
+      i->Header.SizeOfRawData = 0;
+      i->Header.PointerToRawData = 0;
+    }
+  }
+
+  uint32_t SymbolTableStart = CurrentSectionDataOffset;
+
+  // Calculate number of symbols.
+  uint32_t NumberOfSymbols = 0;
+  for (std::vector<COFFParser::Symbol>::iterator i = CP.Symbols.begin(),
+                                                 e = CP.Symbols.end();
+                                                 i != e; ++i) {
+    if (i->AuxSymbols.size() % COFF::SymbolSize != 0) {
+      errs() << "AuxillaryData size not a multiple of symbol size!\n";
+      return false;
+    }
+    i->Header.NumberOfAuxSymbols = i->AuxSymbols.size() / COFF::SymbolSize;
+    NumberOfSymbols += 1 + i->Header.NumberOfAuxSymbols;
+  }
+
+  // Store all the allocated start addresses in the header.
+  CP.Header.NumberOfSections = CP.Sections.size();
+  CP.Header.NumberOfSymbols = NumberOfSymbols;
+  CP.Header.PointerToSymbolTable = SymbolTableStart;
+
+  *reinterpret_cast<support::ulittle32_t *>(&CP.StringTable[0])
+    = CP.StringTable.size();
+
+  return true;
+}
+
+template <typename value_type>
+struct binary_le_impl {
+  value_type Value;
+  binary_le_impl(value_type V) : Value(V) {}
+};
+
+template <typename value_type>
+raw_ostream &operator <<( raw_ostream &OS
+                        , const binary_le_impl<value_type> &BLE) {
+  char Buffer[sizeof(BLE.Value)];
+  support::endian::write_le<value_type, support::unaligned>(Buffer, BLE.Value);
+  OS.write(Buffer, sizeof(BLE.Value));
+  return OS;
+}
+
+template <typename value_type>
+binary_le_impl<value_type> binary_le(value_type V) {
+  return binary_le_impl<value_type>(V);
+}
+
+void writeCOFF(COFFParser &CP, raw_ostream &OS) {
+  OS << binary_le(CP.Header.Machine)
+     << binary_le(CP.Header.NumberOfSections)
+     << binary_le(CP.Header.TimeDateStamp)
+     << binary_le(CP.Header.PointerToSymbolTable)
+     << binary_le(CP.Header.NumberOfSymbols)
+     << binary_le(CP.Header.SizeOfOptionalHeader)
+     << binary_le(CP.Header.Characteristics);
+
+  // Output section table.
+  for (std::vector<COFFParser::Section>::const_iterator i = CP.Sections.begin(),
+                                                        e = CP.Sections.end();
+                                                        i != e; ++i) {
+    OS.write(i->Header.Name, COFF::NameSize);
+    OS << binary_le(i->Header.VirtualSize)
+       << binary_le(i->Header.VirtualAddress)
+       << binary_le(i->Header.SizeOfRawData)
+       << binary_le(i->Header.PointerToRawData)
+       << binary_le(i->Header.PointerToRelocations)
+       << binary_le(i->Header.PointerToLineNumbers)
+       << binary_le(i->Header.NumberOfRelocations)
+       << binary_le(i->Header.NumberOfLineNumbers)
+       << binary_le(i->Header.Characteristics);
+  }
+
+  // Output section data.
+  for (std::vector<COFFParser::Section>::const_iterator i = CP.Sections.begin(),
+                                                        e = CP.Sections.end();
+                                                        i != e; ++i) {
+    if (!i->Data.empty())
+      OS.write(reinterpret_cast<const char*>(&i->Data[0]), i->Data.size());
+  }
+
+  // Output symbol table.
+
+  for (std::vector<COFFParser::Symbol>::const_iterator i = CP.Symbols.begin(),
+                                                       e = CP.Symbols.end();
+                                                       i != e; ++i) {
+    OS.write(i->Header.Name, COFF::NameSize);
+    OS << binary_le(i->Header.Value)
+       << binary_le(i->Header.SectionNumber)
+       << binary_le(i->Header.Type)
+       << binary_le(i->Header.StorageClass)
+       << binary_le(i->Header.NumberOfAuxSymbols);
+    if (!i->AuxSymbols.empty())
+      OS.write( reinterpret_cast<const char*>(&i->AuxSymbols[0])
+              , i->AuxSymbols.size());
+  }
+
+  // Output string table.
+  OS.write(&CP.StringTable[0], CP.StringTable.size());
+}
+
+int main(int argc, char **argv) {
+  cl::ParseCommandLineOptions(argc, argv);
+  sys::PrintStackTraceOnErrorSignal();
+  PrettyStackTraceProgram X(argc, argv);
+  llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.
+
+  OwningPtr<MemoryBuffer> Buf;
+  if (MemoryBuffer::getFileOrSTDIN(Input, Buf))
+    return 1;
+
+  SourceMgr SM;
+  yaml::Stream S(Buf->getBuffer(), SM);
+  COFFParser CP(S);
+  if (!CP.parse()) {
+    errs() << "yaml2obj: Failed to parse YAML file!\n";
+    return 1;
+  }
+  if (!layoutCOFF(CP)) {
+    errs() << "yaml2obj: Failed to layout COFF file!\n";
+    return 1;
+  }
+  writeCOFF(CP, outs());
+}