Rename LLVMCCConfigurationEmitter to LLVMCConfigurationEmitter

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50748 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 1126 insertions, 0 deletions

diff --git a/utils/TableGen/LLVMCConfigurationEmitter.cpp b/utils/TableGen/LLVMCConfigurationEmitter.cpp
new file mode 100644
index 0000000000..73390af9d6
--- /dev/null
+++ b/utils/TableGen/LLVMCConfigurationEmitter.cpp
@@ -0,0 +1,1126 @@
+//===- LLVMCConfigurationEmitter.cpp - Generate LLVMC config --------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open
+// Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This tablegen backend is responsible for emitting LLVMC configuration code.
+//
+//===----------------------------------------------------------------------===//
+
+#include "LLVMCConfigurationEmitter.h"
+#include "Record.h"
+
+#include "llvm/ADT/IntrusiveRefCntPtr.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/Support/Streams.h"
+
+#include <algorithm>
+#include <cassert>
+#include <functional>
+#include <string>
+
+using namespace llvm;
+
+//namespace {
+
+//===----------------------------------------------------------------------===//
+/// Typedefs
+
+typedef std::vector<Record*> RecordVector;
+typedef std::vector<std::string> StrVector;
+
+//===----------------------------------------------------------------------===//
+/// Constants
+
+// Indentation strings
+const char * Indent1 = "    ";
+const char * Indent2 = "        ";
+const char * Indent3 = "            ";
+const char * Indent4 = "                ";
+
+// Default help string
+const char * DefaultHelpString = "NO HELP MESSAGE PROVIDED";
+
+// Name for the "sink" option
+const char * SinkOptionName = "AutoGeneratedSinkOption";
+
+//===----------------------------------------------------------------------===//
+/// Helper functions
+
+std::string InitPtrToString(Init* ptr) {
+  StringInit& val = dynamic_cast<StringInit&>(*ptr);
+  return val.getValue();
+}
+
+// Ensure that the number of args in d is <= min_arguments,
+// throw exception otherwise
+void checkNumberOfArguments (const DagInit* d, unsigned min_arguments) {
+  if (d->getNumArgs() < min_arguments)
+    throw "Property " + d->getOperator()->getAsString()
+      + " has too few arguments!";
+}
+
+
+//===----------------------------------------------------------------------===//
+/// Back-end specific code
+
+// A command-line option can have one of the following types:
+//
+// Switch - a simple switch w/o arguments, e.g. -O2
+//
+// Parameter - an option that takes one(and only one) argument, e.g. -o file,
+// --output=file
+//
+// ParameterList - same as Parameter, but more than one occurence
+// of the option is allowed, e.g. -lm -lpthread
+//
+// Prefix - argument is everything after the prefix,
+// e.g. -Wa,-foo,-bar, -DNAME=VALUE
+//
+// PrefixList - same as Prefix, but more than one option occurence is
+// allowed
+
+namespace OptionType {
+  enum OptionType { Switch, Parameter, ParameterList, Prefix, PrefixList};
+}
+
+bool IsListOptionType (OptionType::OptionType t) {
+  return (t == OptionType::ParameterList || t == OptionType::PrefixList);
+}
+
+// Code duplication here is necessary because one option can affect
+// several tools and those tools may have different actions associated
+// with this option. GlobalOptionDescriptions are used to generate
+// the option registration code, while ToolOptionDescriptions are used
+// to generate tool-specific code.
+
+// Base class for option descriptions
+
+struct OptionDescription {
+  OptionType::OptionType Type;
+  std::string Name;
+
+  OptionDescription(OptionType::OptionType t = OptionType::Switch,
+                    const std::string& n = "")
+  : Type(t), Name(n)
+  {}
+
+  const char* GenTypeDeclaration() const {
+    switch (Type) {
+    case OptionType::PrefixList:
+    case OptionType::ParameterList:
+      return "cl::list<std::string>";
+    case OptionType::Switch:
+      return "cl::opt<bool>";
+    case OptionType::Parameter:
+    case OptionType::Prefix:
+    default:
+      return "cl::opt<std::string>";
+    }
+  }
+
+  std::string GenVariableName() const {
+    switch (Type) {
+    case OptionType::Switch:
+     return "AutoGeneratedSwitch" + Name;
+   case OptionType::Prefix:
+     return "AutoGeneratedPrefix" + Name;
+   case OptionType::PrefixList:
+     return "AutoGeneratedPrefixList" + Name;
+   case OptionType::Parameter:
+     return "AutoGeneratedParameter" + Name;
+   case OptionType::ParameterList:
+   default:
+     return "AutoGeneratedParameterList" + Name;
+   }
+  }
+
+};
+
+// Global option description
+
+namespace GlobalOptionDescriptionFlags {
+  enum GlobalOptionDescriptionFlags { Required = 0x1 };
+}
+
+struct GlobalOptionDescription : public OptionDescription {
+  std::string Help;
+  unsigned Flags;
+
+  // We need t provide a default constructor since
+  // StringMap can only store DefaultConstructible objects
+  GlobalOptionDescription() : OptionDescription(), Flags(0)
+  {}
+
+  GlobalOptionDescription (OptionType::OptionType t, const std::string& n)
+    : OptionDescription(t, n), Help(DefaultHelpString), Flags(0)
+  {}
+
+  bool isRequired() const {
+    return Flags & GlobalOptionDescriptionFlags::Required;
+  }
+  void setRequired() {
+    Flags |= GlobalOptionDescriptionFlags::Required;
+  }
+
+  // Merge two option descriptions
+  void Merge (const GlobalOptionDescription& other)
+  {
+    if (other.Type != Type)
+      throw "Conflicting definitions for the option " + Name + "!";
+
+    if (Help.empty() && !other.Help.empty())
+      Help = other.Help;
+    else if (!Help.empty() && !other.Help.empty())
+      cerr << "Warning: more than one help string defined for option "
+        + Name + "\n";
+
+    Flags |= other.Flags;
+  }
+};
+
+// A GlobalOptionDescription array
+// + some flags affecting generation of option declarations
+struct GlobalOptionDescriptions {
+  typedef StringMap<GlobalOptionDescription> container_type;
+  typedef container_type::const_iterator const_iterator;
+
+  // A list of GlobalOptionDescriptions
+  container_type Descriptions;
+  // Should the emitter generate a "cl::sink" option?
+  bool HasSink;
+
+  const GlobalOptionDescription& FindOption(const std::string& OptName) const {
+    const_iterator I = Descriptions.find(OptName);
+    if (I != Descriptions.end())
+      return I->second;
+    else
+      throw OptName + ": no such option!";
+  }
+
+  // Support for STL-style iteration
+  const_iterator begin() const { return Descriptions.begin(); }
+  const_iterator end() const { return Descriptions.end(); }
+};
+
+
+// Tool-local option description
+
+// Properties without arguments are implemented as flags
+namespace ToolOptionDescriptionFlags {
+  enum ToolOptionDescriptionFlags { StopCompilation = 0x1,
+                                    Forward = 0x2, UnpackValues = 0x4};
+}
+namespace OptionPropertyType {
+  enum OptionPropertyType { AppendCmd };
+}
+
+typedef std::pair<OptionPropertyType::OptionPropertyType, std::string>
+OptionProperty;
+typedef SmallVector<OptionProperty, 4> OptionPropertyList;
+
+struct ToolOptionDescription : public OptionDescription {
+  unsigned Flags;
+  OptionPropertyList Props;
+
+  // StringMap can only store DefaultConstructible objects
+  ToolOptionDescription() : OptionDescription(), Flags(0) {}
+
+  ToolOptionDescription (OptionType::OptionType t, const std::string& n)
+    : OptionDescription(t, n)
+  {}
+
+  // Various boolean properties
+  bool isStopCompilation() const {
+    return Flags & ToolOptionDescriptionFlags::StopCompilation;
+  }
+  void setStopCompilation() {
+    Flags |= ToolOptionDescriptionFlags::StopCompilation;
+  }
+
+  bool isForward() const {
+    return Flags & ToolOptionDescriptionFlags::Forward;
+  }
+  void setForward() {
+    Flags |= ToolOptionDescriptionFlags::Forward;
+  }
+
+  bool isUnpackValues() const {
+    return Flags & ToolOptionDescriptionFlags::UnpackValues;
+  }
+  void setUnpackValues() {
+    Flags |= ToolOptionDescriptionFlags::UnpackValues;
+  }
+
+  void AddProperty (OptionPropertyType::OptionPropertyType t,
+                    const std::string& val)
+  {
+    Props.push_back(std::make_pair(t, val));
+  }
+};
+
+typedef StringMap<ToolOptionDescription> ToolOptionDescriptions;
+
+// Tool information record
+
+namespace ToolFlags {
+  enum ToolFlags { Join = 0x1, Sink = 0x2 };
+}
+
+struct ToolProperties : public RefCountedBase<ToolProperties> {
+  std::string Name;
+  StrVector CmdLine;
+  std::string InLanguage;
+  std::string OutLanguage;
+  std::string OutputSuffix;
+  unsigned Flags;
+  ToolOptionDescriptions OptDescs;
+
+  // Various boolean properties
+  void setSink()      { Flags |= ToolFlags::Sink; }
+  bool isSink() const { return Flags & ToolFlags::Sink; }
+  void setJoin()      { Flags |= ToolFlags::Join; }
+  bool isJoin() const { return Flags & ToolFlags::Join; }
+
+  // Default ctor here is needed because StringMap can only store
+  // DefaultConstructible objects
+  ToolProperties() {}
+  ToolProperties (const std::string& n) : Name(n) {}
+};
+
+
+// A list of Tool information records
+// IntrusiveRefCntPtrs are used because StringMap has no copy constructor
+// (and we want to avoid copying ToolProperties anyway)
+typedef std::vector<IntrusiveRefCntPtr<ToolProperties> > ToolPropertiesList;
+
+
+// Function object for iterating over a list of tool property records
+class CollectProperties {
+private:
+
+  /// Implementation details
+
+  // "Property handler" - a function that extracts information
+  // about a given tool property from its DAG representation
+  typedef void (CollectProperties::*PropertyHandler)(DagInit*);
+
+  // Map from property names -> property handlers
+  typedef StringMap<PropertyHandler> PropertyHandlerMap;
+
+  // "Option property handler" - a function that extracts information
+  // about a given option property from its DAG representation
+  typedef void (CollectProperties::*
+                OptionPropertyHandler)(DagInit*, GlobalOptionDescription &);
+
+  // Map from option property names -> option property handlers
+  typedef StringMap<OptionPropertyHandler> OptionPropertyHandlerMap;
+
+  // Static maps from strings to CollectProperties methods("handlers")
+  static PropertyHandlerMap propertyHandlers_;
+  static OptionPropertyHandlerMap optionPropertyHandlers_;
+  static bool staticMembersInitialized_;
+
+
+  /// This is where the information is stored
+
+  // Current Tool properties
+  ToolProperties& toolProps_;
+  // OptionDescriptions table(used to register options globally)
+  GlobalOptionDescriptions& optDescs_;
+
+public:
+
+  explicit CollectProperties (ToolProperties& p, GlobalOptionDescriptions& d)
+    : toolProps_(p), optDescs_(d)
+  {
+    if (!staticMembersInitialized_) {
+      // Init tool property handlers
+      propertyHandlers_["cmd_line"] = &CollectProperties::onCmdLine;
+      propertyHandlers_["in_language"] = &CollectProperties::onInLanguage;
+      propertyHandlers_["join"] = &CollectProperties::onJoin;
+      propertyHandlers_["out_language"] = &CollectProperties::onOutLanguage;
+      propertyHandlers_["output_suffix"] = &CollectProperties::onOutputSuffix;
+      propertyHandlers_["parameter_option"]
+        = &CollectProperties::onParameter;
+      propertyHandlers_["parameter_list_option"] =
+        &CollectProperties::onParameterList;
+      propertyHandlers_["prefix_option"] = &CollectProperties::onPrefix;
+      propertyHandlers_["prefix_list_option"] =
+        &CollectProperties::onPrefixList;
+      propertyHandlers_["sink"] = &CollectProperties::onSink;
+      propertyHandlers_["switch_option"] = &CollectProperties::onSwitch;
+
+      // Init option property handlers
+      optionPropertyHandlers_["append_cmd"] = &CollectProperties::onAppendCmd;
+      optionPropertyHandlers_["forward"] = &CollectProperties::onForward;
+      optionPropertyHandlers_["help"] = &CollectProperties::onHelp;
+      optionPropertyHandlers_["required"] = &CollectProperties::onRequired;
+      optionPropertyHandlers_["stop_compilation"] =
+        &CollectProperties::onStopCompilation;
+      optionPropertyHandlers_["unpack_values"] =
+        &CollectProperties::onUnpackValues;
+
+      staticMembersInitialized_ = true;
+    }
+  }
+
+  // Gets called for every tool property;
+  // Just forwards to the corresponding property handler.
+  void operator() (Init* i) {
+    DagInit& d = dynamic_cast<DagInit&>(*i);
+    const std::string& property_name = d.getOperator()->getAsString();
+    PropertyHandlerMap::iterator method
+      = propertyHandlers_.find(property_name);
+
+    if (method != propertyHandlers_.end()) {
+      PropertyHandler h = method->second;
+      (this->*h)(&d);
+    }
+    else {
+      throw "Unknown tool property: " + property_name + "!";
+    }
+  }
+
+private:
+
+  /// Property handlers --
+  /// Functions that extract information about tool properties from
+  /// DAG representation.
+
+  void onCmdLine (DagInit* d) {
+    checkNumberOfArguments(d, 1);
+    SplitString(InitPtrToString(d->getArg(0)), toolProps_.CmdLine);
+    if (toolProps_.CmdLine.empty())
+      throw "Tool " + toolProps_.Name + " has empty command line!";
+  }
+
+  void onInLanguage (DagInit* d) {
+    checkNumberOfArguments(d, 1);
+    toolProps_.InLanguage = InitPtrToString(d->getArg(0));
+  }
+
+  void onJoin (DagInit* d) {
+    checkNumberOfArguments(d, 0);
+    toolProps_.setJoin();
+  }
+
+  void onOutLanguage (DagInit* d) {
+    checkNumberOfArguments(d, 1);
+    toolProps_.OutLanguage = InitPtrToString(d->getArg(0));
+  }
+
+  void onOutputSuffix (DagInit* d) {
+    checkNumberOfArguments(d, 1);
+    toolProps_.OutputSuffix = InitPtrToString(d->getArg(0));
+  }
+
+  void onSink (DagInit* d) {
+    checkNumberOfArguments(d, 0);
+    optDescs_.HasSink = true;
+    toolProps_.setSink();
+  }
+
+  void onSwitch (DagInit* d)        { addOption(d, OptionType::Switch); }
+  void onParameter (DagInit* d)     { addOption(d, OptionType::Parameter); }
+  void onParameterList (DagInit* d) { addOption(d, OptionType::ParameterList); }
+  void onPrefix (DagInit* d)        { addOption(d, OptionType::Prefix); }
+  void onPrefixList (DagInit* d)    { addOption(d, OptionType::PrefixList); }
+
+  /// Option property handlers --
+  /// Methods that handle properties that are common for all types of
+  /// options (like append_cmd, stop_compilation)
+
+  void onAppendCmd (DagInit* d, GlobalOptionDescription& o) {
+    checkNumberOfArguments(d, 1);
+    std::string const& cmd = InitPtrToString(d->getArg(0));
+
+    toolProps_.OptDescs[o.Name].AddProperty(OptionPropertyType::AppendCmd, cmd);
+  }
+
+  void onForward (DagInit* d, GlobalOptionDescription& o) {
+    checkNumberOfArguments(d, 0);
+    toolProps_.OptDescs[o.Name].setForward();
+  }
+
+  void onHelp (DagInit* d, GlobalOptionDescription& o) {
+    checkNumberOfArguments(d, 1);
+    const std::string& help_message = InitPtrToString(d->getArg(0));
+
+    o.Help = help_message;
+  }
+
+  void onRequired (DagInit* d, GlobalOptionDescription& o) {
+    checkNumberOfArguments(d, 0);
+    o.setRequired();
+  }
+
+  void onStopCompilation (DagInit* d, GlobalOptionDescription& o) {
+    checkNumberOfArguments(d, 0);
+    if (o.Type != OptionType::Switch)
+      throw std::string("Only options of type Switch can stop compilation!");
+    toolProps_.OptDescs[o.Name].setStopCompilation();
+  }
+
+  void onUnpackValues (DagInit* d, GlobalOptionDescription& o) {
+    checkNumberOfArguments(d, 0);
+    toolProps_.OptDescs[o.Name].setUnpackValues();
+  }
+
+  /// Helper functions
+
+  // Add an option of type t
+  void addOption (DagInit* d, OptionType::OptionType t) {
+    checkNumberOfArguments(d, 2);
+    const std::string& name = InitPtrToString(d->getArg(0));
+
+    GlobalOptionDescription o(t, name);
+    toolProps_.OptDescs[name].Type = t;
+    toolProps_.OptDescs[name].Name = name;
+    processOptionProperties(d, o);
+    insertDescription(o);
+  }
+
+  // Insert new GlobalOptionDescription into GlobalOptionDescriptions list
+  void insertDescription (const GlobalOptionDescription& o)
+  {
+    if (optDescs_.Descriptions.count(o.Name)) {
+      GlobalOptionDescription& D = optDescs_.Descriptions[o.Name];
+      D.Merge(o);
+    }
+    else {
+      optDescs_.Descriptions[o.Name] = o;
+    }
+  }
+
+  // Go through the list of option properties and call a corresponding
+  // handler for each.
+  //
+  // Parameters:
+  // name - option name
+  // d - option property list
+  void processOptionProperties (DagInit* d, GlobalOptionDescription& o) {
+    // First argument is option name
+    checkNumberOfArguments(d, 2);
+
+    for (unsigned B = 1, E = d->getNumArgs(); B!=E; ++B) {
+      DagInit& option_property
+        = dynamic_cast<DagInit&>(*d->getArg(B));
+      const std::string& option_property_name
+        = option_property.getOperator()->getAsString();
+      OptionPropertyHandlerMap::iterator method
+        = optionPropertyHandlers_.find(option_property_name);
+
+      if (method != optionPropertyHandlers_.end()) {
+        OptionPropertyHandler h = method->second;
+        (this->*h)(&option_property, o);
+      }
+      else {
+        throw "Unknown option property: " + option_property_name + "!";
+      }
+    }
+  }
+};
+
+// Static members of CollectProperties
+CollectProperties::PropertyHandlerMap
+CollectProperties::propertyHandlers_;
+
+CollectProperties::OptionPropertyHandlerMap
+CollectProperties::optionPropertyHandlers_;
+
+bool CollectProperties::staticMembersInitialized_ = false;
+
+
+// Gather information from the parsed TableGen data
+// (Basically a wrapper for CollectProperties)
+void CollectToolProperties (RecordVector::const_iterator B,
+                            RecordVector::const_iterator E,
+                            ToolPropertiesList& TPList,
+                            GlobalOptionDescriptions& OptDescs)
+{
+  // Iterate over a properties list of every Tool definition
+  for (;B!=E;++B) {
+    RecordVector::value_type T = *B;
+    ListInit* PropList = T->getValueAsListInit("properties");
+
+    IntrusiveRefCntPtr<ToolProperties>
+      ToolProps(new ToolProperties(T->getName()));
+
+    std::for_each(PropList->begin(), PropList->end(),
+                  CollectProperties(*ToolProps, OptDescs));
+    TPList.push_back(ToolProps);
+  }
+}
+
+// Used by EmitGenerateActionMethod
+void EmitOptionPropertyHandlingCode (const ToolProperties& P,
+                                     const ToolOptionDescription& D,
+                                     std::ostream& O)
+{
+  // if clause
+  O << Indent2 << "if (";
+  if (D.Type == OptionType::Switch)
+    O << D.GenVariableName();
+  else
+    O << '!' << D.GenVariableName() << ".empty()";
+
+  O <<") {\n";
+
+  // Handle option properties that take an argument
+  for (OptionPropertyList::const_iterator B = D.Props.begin(),
+        E = D.Props.end(); B!=E; ++B) {
+    const OptionProperty& val = *B;
+
+    switch (val.first) {
+      // (append_cmd cmd) property
+    case OptionPropertyType::AppendCmd:
+      O << Indent3 << "vec.push_back(\"" << val.second << "\");\n";
+      break;
+      // Other properties with argument
+    default:
+      break;
+    }
+  }
+
+  // Handle flags
+
+  // (forward) property
+  if (D.isForward()) {
+    switch (D.Type) {
+    case OptionType::Switch:
+      O << Indent3 << "vec.push_back(\"-" << D.Name << "\");\n";
+      break;
+    case OptionType::Parameter:
+      O << Indent3 << "vec.push_back(\"-" << D.Name << "\");\n";
+      O << Indent3 << "vec.push_back(" << D.GenVariableName() << ");\n";
+      break;
+    case OptionType::Prefix:
+      O << Indent3 << "vec.push_back(\"-" << D.Name << "\" + "
+        << D.GenVariableName() << ");\n";
+      break;
+    case OptionType::PrefixList:
+      O << Indent3 << "for (" << D.GenTypeDeclaration()
+        << "::iterator B = " << D.GenVariableName() << ".begin(),\n"
+        << Indent3 << "E = " << D.GenVariableName() << ".end(); B != E; ++B)\n"
+        << Indent4 << "vec.push_back(\"-" << D.Name << "\" + "
+        << "*B);\n";
+      break;
+    case OptionType::ParameterList:
+      O << Indent3 << "for (" << D.GenTypeDeclaration()
+        << "::iterator B = " << D.GenVariableName() << ".begin(),\n"
+        << Indent3 << "E = " << D.GenVariableName()
+        << ".end() ; B != E; ++B) {\n"
+        << Indent4 << "vec.push_back(\"-" << D.Name << "\");\n"
+        << Indent4 << "vec.push_back(*B);\n"
+        << Indent3 << "}\n";
+      break;
+    }
+  }
+
+  // (unpack_values) property
+  if (D.isUnpackValues()) {
+    if (IsListOptionType(D.Type)) {
+      O << Indent3 << "for (" << D.GenTypeDeclaration()
+        << "::iterator B = " << D.GenVariableName() << ".begin(),\n"
+        << Indent3 << "E = " << D.GenVariableName()
+        << ".end(); B != E; ++B)\n"
+        << Indent4 << "Tool::UnpackValues(*B, vec);\n";
+    }
+    else if (D.Type == OptionType::Prefix || D.Type == OptionType::Parameter){
+      O << Indent3 << "Tool::UnpackValues("
+        << D.GenVariableName() << ", vec);\n";
+    }
+    else {
+      // TOFIX: move this to the type-checking phase
+      throw std::string("Switches can't have unpack_values property!");
+    }
+  }
+
+  // close if clause
+  O << Indent2 << "}\n";
+}
+
+// Emite one of two versions of GenerateAction method
+void EmitGenerateActionMethod (const ToolProperties& P, int V, std::ostream& O)
+{
+  assert(V==1 || V==2);
+  if (V==1)
+    O << Indent1 << "Action GenerateAction(const PathVector& inFiles,\n";
+  else
+    O << Indent1 << "Action GenerateAction(const sys::Path& inFile,\n";
+
+  O << Indent2 << "const sys::Path& outFile) const\n"
+    << Indent1 << "{\n"
+    << Indent2 << "std::vector<std::string> vec;\n";
+
+  // Parse CmdLine tool property
+  if(P.CmdLine.empty())
+    throw "Tool " + P.Name + " has empty command line!";
+
+  StrVector::const_iterator I = P.CmdLine.begin();
+  ++I;
+  for (StrVector::const_iterator E = P.CmdLine.end(); I != E; ++I) {
+    const std::string& cmd = *I;
+    O << Indent2;
+    if (cmd == "$INFILE") {
+      if (V==1)
+        O << "for (PathVector::const_iterator B = inFiles.begin()"
+          << ", E = inFiles.end();\n"
+          << Indent2 << "B != E; ++B)\n"
+          << Indent3 << "vec.push_back(B->toString());\n";
+      else
+        O << "vec.push_back(inFile.toString());\n";
+    }
+    else if (cmd == "$OUTFILE") {
+      O << "vec.push_back(outFile.toString());\n";
+    }
+    else {
+      O << "vec.push_back(\"" << cmd << "\");\n";
+    }
+  }
+
+  // For every understood option, emit handling code
+  for (ToolOptionDescriptions::const_iterator B = P.OptDescs.begin(),
+        E = P.OptDescs.end(); B != E; ++B) {
+    const ToolOptionDescription& val = B->second;
+    EmitOptionPropertyHandlingCode(P, val, O);
+  }
+
+  // Handle Sink property
+  if (P.isSink()) {
+    O << Indent2 << "if (!" << SinkOptionName << ".empty()) {\n"
+      << Indent3 << "vec.insert(vec.end(), "
+      << SinkOptionName << ".begin(), " << SinkOptionName << ".end());\n"
+      << Indent2 << "}\n";
+  }
+
+  O << Indent2 << "return Action(\"" << P.CmdLine.at(0) << "\", vec);\n"
+    << Indent1 << "}\n\n";
+}
+
+// Emit GenerateAction methods for Tool classes
+void EmitGenerateActionMethods (const ToolProperties& P, std::ostream& O) {
+
+  if (!P.isJoin())
+    O << Indent1 << "Action GenerateAction(const PathVector& inFiles,\n"
+      << Indent2 << "const llvm::sys::Path& outFile) const\n"
+      << Indent1 << "{\n"
+      << Indent2 << "throw std::runtime_error(\"" << P.Name
+      << " is not a Join tool!\");\n"
+      << Indent1 << "}\n\n";
+  else
+    EmitGenerateActionMethod(P, 1, O);
+
+  EmitGenerateActionMethod(P, 2, O);
+}
+
+// Emit IsLast() method for Tool classes
+void EmitIsLastMethod (const ToolProperties& P, std::ostream& O) {
+  O << Indent1 << "bool IsLast() const {\n"
+    << Indent2 << "bool last = false;\n";
+
+  for (ToolOptionDescriptions::const_iterator B = P.OptDescs.begin(),
+        E = P.OptDescs.end(); B != E; ++B) {
+    const ToolOptionDescription& val = B->second;
+
+    if (val.isStopCompilation())
+      O << Indent2
+        << "if (" << val.GenVariableName()
+        << ")\n" << Indent3 << "last = true;\n";
+  }
+
+  O << Indent2 << "return last;\n"
+    << Indent1 <<  "}\n\n";
+}
+
+// Emit static [Input,Output]Language() methods for Tool classes
+void EmitInOutLanguageMethods (const ToolProperties& P, std::ostream& O) {
+  O << Indent1 << "const char* InputLanguage() const {\n"
+    << Indent2 << "return \"" << P.InLanguage << "\";\n"
+    << Indent1 << "}\n\n";
+
+  O << Indent1 << "const char* OutputLanguage() const {\n"
+    << Indent2 << "return \"" << P.OutLanguage << "\";\n"
+    << Indent1 << "}\n\n";
+}
+
+// Emit static [Input,Output]Language() methods for Tool classes
+void EmitOutputSuffixMethod (const ToolProperties& P, std::ostream& O) {
+  O << Indent1 << "const char* OutputSuffix() const {\n"
+    << Indent2 << "return \"" << P.OutputSuffix << "\";\n"
+    << Indent1 << "}\n\n";
+}
+
+// Emit static Name() method for Tool classes
+void EmitNameMethod (const ToolProperties& P, std::ostream& O) {
+  O << Indent1 << "const char* Name() const {\n"
+    << Indent2 << "return \"" << P.Name << "\";\n"
+    << Indent1 << "}\n\n";
+}
+
+// Emit static Name() method for Tool classes
+void EmitIsJoinMethod (const ToolProperties& P, std::ostream& O) {
+  O << Indent1 << "bool IsJoin() const {\n";
+  if (P.isJoin())
+    O << Indent2 << "return true;\n";
+  else
+    O << Indent2 << "return false;\n";
+  O << Indent1 << "}\n\n";
+}
+
+// Emit a Tool class definition
+void EmitToolClassDefinition (const ToolProperties& P, std::ostream& O) {
+
+  if(P.Name == "root")
+    return;
+
+  // Header
+  O << "class " << P.Name << " : public ";
+  if (P.isJoin())
+    O << "JoinTool";
+  else
+    O << "Tool";
+  O << " {\npublic:\n";
+
+  EmitNameMethod(P, O);
+  EmitInOutLanguageMethods(P, O);
+  EmitOutputSuffixMethod(P, O);
+  EmitIsJoinMethod(P, O);
+  EmitGenerateActionMethods(P, O);
+  EmitIsLastMethod(P, O);
+
+  // Close class definition
+  O << "};\n\n";
+}
+
+// Iterate over a list of option descriptions and emit registration code
+void EmitOptionDescriptions (const GlobalOptionDescriptions& descs,
+                             std::ostream& O)
+{
+  // Emit static cl::Option variables
+  for (GlobalOptionDescriptions::const_iterator B = descs.begin(),
+         E = descs.end(); B!=E; ++B) {
+    const GlobalOptionDescription& val = B->second;
+
+    O << val.GenTypeDeclaration() << ' '
+      << val.GenVariableName()
+      << "(\"" << val.Name << '\"';
+
+    if (val.Type == OptionType::Prefix || val.Type == OptionType::PrefixList)
+      O << ", cl::Prefix";
+
+    if (val.isRequired()) {
+      switch (val.Type) {
+      case OptionType::PrefixList:
+      case OptionType::ParameterList:
+        O << ", cl::OneOrMore";
+        break;
+      default:
+        O << ", cl::Required";
+      }
+    }
+
+    O << ", cl::desc(\"" << val.Help << "\"));\n";
+  }
+
+  if (descs.HasSink)
+    O << "cl::list<std::string> " << SinkOptionName << "(cl::Sink);\n";
+
+  O << '\n';
+}
+
+void EmitPopulateLanguageMap (const RecordKeeper& Records, std::ostream& O)
+{
+  // Get the relevant field out of RecordKeeper
+  Record* LangMapRecord = Records.getDef("LanguageMap");
+  if (!LangMapRecord)
+    throw std::string("Language map definition not found!");
+
+  ListInit* LangsToSuffixesList = LangMapRecord->getValueAsListInit("map");
+  if (!LangsToSuffixesList)
+    throw std::string("Error in the language map definition!");
+
+  // Generate code
+  O << "void llvmc::PopulateLanguageMap(LanguageMap& language_map) {\n";
+
+  for (unsigned i = 0; i < LangsToSuffixesList->size(); ++i) {
+    Record* LangToSuffixes = LangsToSuffixesList->getElementAsRecord(i);
+
+    const std::string& Lang = LangToSuffixes->getValueAsString("lang");
+    const ListInit* Suffixes = LangToSuffixes->getValueAsListInit("suffixes");
+
+    for (unsigned i = 0; i < Suffixes->size(); ++i)
+      O << Indent1 << "language_map[\""
+        << InitPtrToString(Suffixes->getElement(i))
+        << "\"] = \"" << Lang << "\";\n";
+  }
+
+  O << "}\n\n";
+}
+
+// Fills in two tables that map tool names to (input, output) languages.
+// Used by the typechecker.
+void FillInToolToLang (const ToolPropertiesList& TPList,
+                       StringMap<std::string>& ToolToInLang,
+                       StringMap<std::string>& ToolToOutLang) {
+  for (ToolPropertiesList::const_iterator B = TPList.begin(), E = TPList.end();
+       B != E; ++B) {
+    const ToolProperties& P = *(*B);
+    ToolToInLang[P.Name] = P.InLanguage;
+    ToolToOutLang[P.Name] = P.OutLanguage;
+  }
+}
+
+// Check that all output and input language names match.
+// TOFIX: check for cycles.
+// TOFIX: check for multiple default edges.
+void TypecheckGraph (Record* CompilationGraph,
+                     const ToolPropertiesList& TPList) {
+  StringMap<std::string> ToolToInLang;
+  StringMap<std::string> ToolToOutLang;
+
+  FillInToolToLang(TPList, ToolToInLang, ToolToOutLang);
+  ListInit* edges = CompilationGraph->getValueAsListInit("edges");
+  StringMap<std::string>::iterator IAE = ToolToInLang.end();
+  StringMap<std::string>::iterator IBE = ToolToOutLang.end();
+
+  for (unsigned i = 0; i < edges->size(); ++i) {
+    Record* Edge = edges->getElementAsRecord(i);
+    Record* A = Edge->getValueAsDef("a");
+    Record* B = Edge->getValueAsDef("b");
+    StringMap<std::string>::iterator IA = ToolToOutLang.find(A->getName());
+    StringMap<std::string>::iterator IB = ToolToInLang.find(B->getName());
+    if(IA == IAE)
+      throw A->getName() + ": no such tool!";
+    if(IB == IBE)
+      throw B->getName() + ": no such tool!";
+    if(A->getName() != "root" && IA->second != IB->second)
+      throw "Edge " + A->getName() + "->" + B->getName()
+        + ": output->input language mismatch";
+    if(B->getName() == "root")
+      throw std::string("Edges back to the root are not allowed!");
+  }
+}
+
+// Helper function used by EmitEdgePropertyTest.
+void EmitEdgePropertyTest1Arg(const DagInit& Prop,
+                              const GlobalOptionDescriptions& OptDescs,
+                              std::ostream& O) {
+  checkNumberOfArguments(&Prop, 1);
+  const std::string& OptName = InitPtrToString(Prop.getArg(0));
+  const GlobalOptionDescription& OptDesc = OptDescs.FindOption(OptName);
+  if (OptDesc.Type != OptionType::Switch)
+    throw OptName + ": incorrect option type!";
+  O << OptDesc.GenVariableName();
+}
+
+// Helper function used by EmitEdgePropertyTest.
+void EmitEdgePropertyTest2Args(const std::string& PropName,
+                               const DagInit& Prop,
+                               const GlobalOptionDescriptions& OptDescs,
+                               std::ostream& O) {
+  checkNumberOfArguments(&Prop, 2);
+  const std::string& OptName = InitPtrToString(Prop.getArg(0));
+  const std::string& OptArg = InitPtrToString(Prop.getArg(1));
+  const GlobalOptionDescription& OptDesc = OptDescs.FindOption(OptName);
+
+  if (PropName == "parameter_equals") {
+    if (OptDesc.Type != OptionType::Parameter
+        && OptDesc.Type != OptionType::Prefix)
+      throw OptName + ": incorrect option type!";
+    O << OptDesc.GenVariableName() << " == \"" << OptArg << "\"";
+  }
+  else if (PropName == "element_in_list") {
+    if (OptDesc.Type != OptionType::ParameterList
+        && OptDesc.Type != OptionType::PrefixList)
+      throw OptName + ": incorrect option type!";
+    const std::string& VarName = OptDesc.GenVariableName();
+    O << "std::find(" << VarName << ".begin(),\n"
+      << Indent3 << VarName << ".end(), \""
+      << OptArg << "\") != " << VarName << ".end()";
+  }
+  else
+    throw PropName + ": unknown edge property!";
+}
+
+// Helper function used by EmitEdgeClass.
+void EmitEdgePropertyTest(const std::string& PropName,
+                          const DagInit& Prop,
+                          const GlobalOptionDescriptions& OptDescs,
+                          std::ostream& O) {
+  if (PropName == "switch_on")
+    EmitEdgePropertyTest1Arg(Prop, OptDescs, O);
+  else
+    EmitEdgePropertyTest2Args(PropName, Prop, OptDescs, O);
+}
+
+// Emit a single Edge* class.
+void EmitEdgeClass(unsigned N, const std::string& Target,
+                   ListInit* Props, const GlobalOptionDescriptions& OptDescs,
+                   std::ostream& O) {
+  bool IsDefault = false;
+
+  // Class constructor.
+  O << "class Edge" << N << ": public Edge {\n"
+    << "public:\n"
+    << Indent1 << "Edge" << N << "() : Edge(\"" << Target
+    << "\") {}\n\n"
+
+    // Function isEnabled().
+    << Indent1 << "bool isEnabled() const {\n"
+    << Indent2 << "bool ret = false;\n";
+
+  for (size_t i = 0, PropsSize = Props->size(); i < PropsSize; ++i) {
+    const DagInit& Prop = dynamic_cast<DagInit&>(*Props->getElement(i));
+    const std::string& PropName = Prop.getOperator()->getAsString();
+
+    if (PropName == "default")
+      IsDefault = true;
+
+    O << Indent2 << "if (ret || (";
+    if (PropName == "and") {
+      O << '(';
+      for (unsigned j = 0, NumArgs = Prop.getNumArgs(); j < NumArgs; ++j) {
+        const DagInit& InnerProp = dynamic_cast<DagInit&>(*Prop.getArg(j));
+        const std::string& InnerPropName =
+          InnerProp.getOperator()->getAsString();
+        EmitEdgePropertyTest(InnerPropName, InnerProp, OptDescs, O);
+        if (j != NumArgs - 1)
+          O << ")\n" << Indent3 << " && (";
+        else
+          O << ')';
+      }
+    }
+    else {
+      EmitEdgePropertyTest(PropName, Prop, OptDescs, O);
+    }
+    O << "))\n" << Indent3 << "ret = true;\n";
+  }
+
+  O << Indent2 << "return ret;\n"
+    << Indent1 << "};\n\n"
+
+  // Function isDefault().
+    << Indent1 << "bool isDefault() const { return ";
+  if (IsDefault)
+    O << "true";
+  else
+    O << "false";
+  O <<"; }\n};\n\n";
+}
+
+// Emit Edge* classes that represent graph edges.
+void EmitEdgeClasses (Record* CompilationGraph,
+                      const GlobalOptionDescriptions& OptDescs,
+                      std::ostream& O) {
+  ListInit* edges = CompilationGraph->getValueAsListInit("edges");
+
+  for (unsigned i = 0; i < edges->size(); ++i) {
+    Record* Edge = edges->getElementAsRecord(i);
+    Record* B = Edge->getValueAsDef("b");
+    ListInit* Props = Edge->getValueAsListInit("props");
+
+    if (Props->empty())
+      continue;
+
+    EmitEdgeClass(i, B->getName(), Props, OptDescs, O);
+  }
+}
+
+void EmitPopulateCompilationGraph (Record* CompilationGraph,
+                                   std::ostream& O)
+{
+  ListInit* edges = CompilationGraph->getValueAsListInit("edges");
+
+  // Generate code
+  O << "void llvmc::PopulateCompilationGraph(CompilationGraph& G) {\n"
+    << Indent1 << "PopulateLanguageMap(G.ExtsToLangs);\n\n";
+
+  // Insert vertices
+
+  RecordVector Tools = Records.getAllDerivedDefinitions("Tool");
+  if (Tools.empty())
+    throw std::string("No tool definitions found!");
+
+  for (RecordVector::iterator B = Tools.begin(), E = Tools.end(); B != E; ++B) {
+    const std::string& Name = (*B)->getName();
+    if(Name != "root")
+      O << Indent1 << "G.insertNode(new "
+        << Name << "());\n";
+  }
+
+  O << '\n';
+
+  // Insert edges
+  for (unsigned i = 0; i < edges->size(); ++i) {
+    Record* Edge = edges->getElementAsRecord(i);
+    Record* A = Edge->getValueAsDef("a");
+    Record* B = Edge->getValueAsDef("b");
+    ListInit* Props = Edge->getValueAsListInit("props");
+
+    O << Indent1 << "G.insertEdge(\"" << A->getName() << "\", ";
+
+    if (Props->empty())
+      O << "new SimpleEdge(\"" << B->getName() << "\")";
+    else
+      O << "new Edge" << i << "()";
+
+    O << ");\n";
+  }
+
+  O << "}\n\n";
+}
+
+
+// End of anonymous namespace
+//}
+
+// Back-end entry point
+void LLVMCCConfigurationEmitter::run (std::ostream &O) {
+  // Emit file header
+  EmitSourceFileHeader("LLVMC Configuration Library", O);
+
+  // Get a list of all defined Tools
+  RecordVector Tools = Records.getAllDerivedDefinitions("Tool");
+  if (Tools.empty())
+    throw std::string("No tool definitions found!");
+
+  // Gather information from the Tool descriptions
+  ToolPropertiesList tool_props;
+  GlobalOptionDescriptions opt_descs;
+  CollectToolProperties(Tools.begin(), Tools.end(), tool_props, opt_descs);
+
+  // Emit global option registration code
+  EmitOptionDescriptions(opt_descs, O);
+
+  // Emit PopulateLanguageMap function
+  // (a language map maps from file extensions to language names)
+  EmitPopulateLanguageMap(Records, O);
+
+  // Emit Tool classes
+  for (ToolPropertiesList::const_iterator B = tool_props.begin(),
+         E = tool_props.end(); B!=E; ++B)
+    EmitToolClassDefinition(*(*B), O);
+
+  Record* CompilationGraphRecord = Records.getDef("CompilationGraph");
+  if (!CompilationGraphRecord)
+    throw std::string("Compilation graph description not found!");
+
+  // Typecheck the compilation graph.
+  TypecheckGraph(CompilationGraphRecord, tool_props);
+
+  // Emit Edge* classes.
+  EmitEdgeClasses(CompilationGraphRecord, opt_descs, O);
+
+  // Emit PopulateCompilationGraph function
+  EmitPopulateCompilationGraph(CompilationGraphRecord, O);
+
+  // EOF
+}