7 files changed, 831 insertions, 0 deletions
diff --git a/include/llvm/CompilerDriver/Action.h b/include/llvm/CompilerDriver/Action.h
new file mode 100644
index 0000000..7014139
--- /dev/null
+++ b/include/llvm/CompilerDriver/Action.h
@@ -0,0 +1,50 @@
+//===--- Action.h - The LLVM Compiler Driver --------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open
+// Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  Action - encapsulates a single shell command.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_INCLUDE_COMPILER_DRIVER_ACTION_H
+#define LLVM_INCLUDE_COMPILER_DRIVER_ACTION_H
+
+#include <string>
+#include <vector>
+
+namespace llvmc {
+
+  typedef std::vector<std::string> StrVector;
+
+  /// Action - A class that encapsulates a single shell command.
+  class Action {
+    /// Command_ - The actual command (for example, 'ls').
+    std::string Command_;
+    /// Args_ - Command arguments. Stdout redirection ("> file") is allowed.
+    std::vector<std::string> Args_;
+    /// StopCompilation_ - Should we stop compilation after executing
+    /// this action?
+    bool StopCompilation_;
+    /// OutFile_ - The output file name.
+    std::string OutFile_;
+
+  public:
+    Action (const std::string& C, const StrVector& A,
+            bool S, const std::string& O)
+      : Command_(C), Args_(A), StopCompilation_(S), OutFile_(O)
+    {}
+
+    /// Execute - Executes the represented action.
+    int Execute () const;
+    bool StopCompilation () const { return StopCompilation_; }
+    const std::string& OutFile() { return OutFile_; }
+  };
+
+}
+
+#endif // LLVM_INCLUDE_COMPILER_DRIVER_ACTION_H
diff --git a/include/llvm/CompilerDriver/Common.td b/include/llvm/CompilerDriver/Common.td
new file mode 100644
index 0000000..1f6bacc
--- /dev/null
+++ b/include/llvm/CompilerDriver/Common.td
@@ -0,0 +1,118 @@
+//===- Common.td - Common definitions for LLVMC2  ----------*- tablegen -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains common definitions used in llvmc2 tool description files.
+//
+//===----------------------------------------------------------------------===//
+
+class Tool<list<dag> l> {
+      list<dag> properties = l;
+}
+
+// Possible Tool properties.
+
+def in_language;
+def out_language;
+def output_suffix;
+def cmd_line;
+def join;
+def sink;
+def actions;
+
+// Possible option types.
+
+def alias_option;
+def switch_option;
+def parameter_option;
+def parameter_list_option;
+def prefix_option;
+def prefix_list_option;
+
+// Possible option properties.
+
+def extern;
+def help;
+def hidden;
+def multi_val;
+def one_or_more;
+def really_hidden;
+def required;
+def zero_or_one;
+
+// Empty DAG marker.
+def empty;
+
+// The 'case' construct.
+def case;
+
+// Boolean operators.
+def and;
+def or;
+
+// Primitive tests.
+def switch_on;
+def parameter_equals;
+def element_in_list;
+def input_languages_contain;
+def not_empty;
+def default;
+
+// Possible actions.
+
+def append_cmd;
+def forward;
+def forward_as;
+def stop_compilation;
+def unpack_values;
+def error;
+
+// Increase/decrease the edge weight.
+def inc_weight;
+def dec_weight;
+
+// Used to specify plugin priority.
+class PluginPriority<int p> {
+      int priority = p;
+}
+
+// Option list - used to specify aliases and sometimes help strings.
+class OptionList<list<dag> l> {
+      list<dag> options = l;
+}
+
+// Map from suffixes to language names
+
+class LangToSuffixes<string str, list<string> lst> {
+      string lang = str;
+      list<string> suffixes = lst;
+}
+
+class LanguageMap<list<LangToSuffixes> lst> {
+      list<LangToSuffixes> map = lst;
+}
+
+// Compilation graph
+
+class EdgeBase<string t1, string t2, dag d> {
+      string a = t1;
+      string b = t2;
+      dag weight = d;
+}
+
+class Edge<string t1, string t2> : EdgeBase<t1, t2, (empty)>;
+
+// Edge and SimpleEdge are synonyms.
+class SimpleEdge<string t1, string t2> : EdgeBase<t1, t2, (empty)>;
+
+// Optionally enabled edge.
+class OptionalEdge<string t1, string t2, dag props> : EdgeBase<t1, t2, props>;
+
+class CompilationGraph<list<EdgeBase> lst> {
+      list<EdgeBase> edges = lst;
+}
diff --git a/include/llvm/CompilerDriver/CompilationGraph.h b/include/llvm/CompilerDriver/CompilationGraph.h
new file mode 100644
index 0000000..825d4c4
--- /dev/null
+++ b/include/llvm/CompilerDriver/CompilationGraph.h
@@ -0,0 +1,325 @@
+//===--- CompilationGraph.h - The LLVM Compiler Driver ----------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open
+// Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  Compilation graph - definition.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_INCLUDE_COMPILER_DRIVER_COMPILATION_GRAPH_H
+#define LLVM_INCLUDE_COMPILER_DRIVER_COMPILATION_GRAPH_H
+
+#include "llvm/CompilerDriver/Tool.h"
+
+#include "llvm/ADT/GraphTraits.h"
+#include "llvm/ADT/IntrusiveRefCntPtr.h"
+#include "llvm/ADT/iterator.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/ADT/StringSet.h"
+#include "llvm/System/Path.h"
+
+#include <cassert>
+#include <string>
+
+namespace llvmc {
+
+  class CompilationGraph;
+  typedef llvm::StringSet<> InputLanguagesSet;
+
+  /// LanguageMap - Maps from extensions to language names.
+  class LanguageMap : public llvm::StringMap<std::string> {
+  public:
+
+    /// GetLanguage -  Find the language name corresponding to a given file.
+    const std::string& GetLanguage(const llvm::sys::Path&) const;
+  };
+
+  /// Edge - Represents an edge of the compilation graph.
+  class Edge : public llvm::RefCountedBaseVPTR<Edge> {
+  public:
+    Edge(const std::string& T) : ToolName_(T) {}
+    virtual ~Edge() {};
+
+    const std::string& ToolName() const { return ToolName_; }
+    virtual unsigned Weight(const InputLanguagesSet& InLangs) const = 0;
+  private:
+    std::string ToolName_;
+  };
+
+  /// SimpleEdge - An edge that has no properties.
+  class SimpleEdge : public Edge {
+  public:
+    SimpleEdge(const std::string& T) : Edge(T) {}
+    unsigned Weight(const InputLanguagesSet&) const { return 1; }
+  };
+
+  /// Node - A node (vertex) of the compilation graph.
+  struct Node {
+    // A Node holds a list of the outward edges.
+    typedef llvm::SmallVector<llvm::IntrusiveRefCntPtr<Edge>, 3> container_type;
+    typedef container_type::iterator iterator;
+    typedef container_type::const_iterator const_iterator;
+
+    Node() : OwningGraph(0), InEdges(0) {}
+    Node(CompilationGraph* G) : OwningGraph(G), InEdges(0) {}
+    Node(CompilationGraph* G, Tool* T) :
+      OwningGraph(G), ToolPtr(T), InEdges(0) {}
+
+    bool HasChildren() const { return !OutEdges.empty(); }
+    const std::string Name() const
+    { return ToolPtr ? ToolPtr->Name() : "root"; }
+
+    // Iteration.
+    iterator EdgesBegin() { return OutEdges.begin(); }
+    const_iterator EdgesBegin() const { return OutEdges.begin(); }
+    iterator EdgesEnd() { return OutEdges.end(); }
+    const_iterator EdgesEnd() const { return OutEdges.end(); }
+
+    /// AddEdge - Add an outward edge. Takes ownership of the provided
+    /// Edge object.
+    void AddEdge(Edge* E);
+
+    // Inward edge counter. Used to implement topological sort.
+    void IncrInEdges() { ++InEdges; }
+    void DecrInEdges() { --InEdges; }
+    bool HasNoInEdges() const { return InEdges == 0; }
+
+    // Needed to implement NodeChildIterator/GraphTraits
+    CompilationGraph* OwningGraph;
+    // The corresponding Tool.
+    // WARNING: ToolPtr can be NULL (for the root node).
+    llvm::IntrusiveRefCntPtr<Tool> ToolPtr;
+    // Links to children.
+    container_type OutEdges;
+    // Inward edge counter. Updated in
+    // CompilationGraph::insertEdge(). Used for topological sorting.
+    unsigned InEdges;
+  };
+
+  class NodesIterator;
+
+  /// CompilationGraph - The compilation graph itself.
+  class CompilationGraph {
+    /// nodes_map_type - The main data structure.
+    typedef llvm::StringMap<Node> nodes_map_type;
+    /// tools_vector_type, tools_map_type - Data structures used to
+    /// map from language names to tools. (We can have several tools
+    /// associated with each language name, hence the need for a
+    /// vector.)
+    typedef
+    llvm::SmallVector<llvm::IntrusiveRefCntPtr<Edge>, 3> tools_vector_type;
+    typedef llvm::StringMap<tools_vector_type> tools_map_type;
+
+    /// ToolsMap - Map from language names to lists of tool names.
+    tools_map_type ToolsMap;
+    /// NodesMap - Map from tool names to Tool objects.
+    nodes_map_type NodesMap;
+
+  public:
+
+    typedef nodes_map_type::iterator nodes_iterator;
+    typedef nodes_map_type::const_iterator const_nodes_iterator;
+
+    CompilationGraph();
+
+    /// insertNode - Insert a new node into the graph. Takes
+    /// ownership of the object.
+    void insertNode(Tool* T);
+
+    /// insertEdge - Insert a new edge into the graph. Takes ownership
+    /// of the Edge object.
+    void insertEdge(const std::string& A, Edge* E);
+
+    /// Build - Build target(s) from the input file set. Command-line
+    /// options are passed implicitly as global variables.
+    int Build(llvm::sys::Path const& TempDir, const LanguageMap& LangMap);
+
+    /// Check - Check the compilation graph for common errors like
+    /// cycles, input/output language mismatch and multiple default
+    /// edges. Prints error messages and in case it finds any errors.
+    int Check();
+
+    /// getNode - Return a reference to the node correponding to the
+    /// given tool name. Throws std::runtime_error.
+    Node& getNode(const std::string& ToolName);
+    const Node& getNode(const std::string& ToolName) const;
+
+    /// viewGraph - This function is meant for use from the debugger.
+    /// You can just say 'call G->viewGraph()' and a ghostview window
+    /// should pop up from the program, displaying the compilation
+    /// graph. This depends on there being a 'dot' and 'gv' program
+    /// in your path.
+    void viewGraph();
+
+    /// writeGraph - Write Graphviz .dot source file to the current direcotry.
+    void writeGraph(const std::string& OutputFilename);
+
+    // GraphTraits support.
+    friend NodesIterator GraphBegin(CompilationGraph*);
+    friend NodesIterator GraphEnd(CompilationGraph*);
+
+  private:
+    // Helper functions.
+
+    /// getToolsVector - Return a reference to the list of tool names
+    /// corresponding to the given language name. Throws
+    /// std::runtime_error.
+    const tools_vector_type& getToolsVector(const std::string& LangName) const;
+
+    /// PassThroughGraph - Pass the input file through the toolchain
+    /// starting at StartNode.
+    void PassThroughGraph (const llvm::sys::Path& In, const Node* StartNode,
+                           const InputLanguagesSet& InLangs,
+                           const llvm::sys::Path& TempDir,
+                           const LanguageMap& LangMap) const;
+
+    /// FindToolChain - Find head of the toolchain corresponding to
+    /// the given file.
+    const Node* FindToolChain(const llvm::sys::Path& In,
+                              const std::string* ForceLanguage,
+                              InputLanguagesSet& InLangs,
+                              const LanguageMap& LangMap) const;
+
+    /// BuildInitial - Traverse the initial parts of the toolchains.
+    void BuildInitial(InputLanguagesSet& InLangs,
+                      const llvm::sys::Path& TempDir,
+                      const LanguageMap& LangMap);
+
+    /// TopologicalSort - Sort the nodes in topological order.
+    void TopologicalSort(std::vector<const Node*>& Out);
+    /// TopologicalSortFilterJoinNodes - Call TopologicalSort and
+    /// filter the resulting list to include only Join nodes.
+    void TopologicalSortFilterJoinNodes(std::vector<const Node*>& Out);
+
+    // Functions used to implement Check().
+
+    /// CheckLanguageNames - Check that output/input language names
+    /// match for all nodes.
+    int CheckLanguageNames() const;
+    /// CheckMultipleDefaultEdges - check that there are no multiple
+    /// default default edges.
+    int CheckMultipleDefaultEdges() const;
+    /// CheckCycles - Check that there are no cycles in the graph.
+    int CheckCycles();
+
+  };
+
+  // GraphTraits support code.
+
+  /// NodesIterator - Auxiliary class needed to implement GraphTraits
+  /// support. Can be generalised to something like value_iterator
+  /// for map-like containers.
+  class NodesIterator : public CompilationGraph::nodes_iterator {
+    typedef CompilationGraph::nodes_iterator super;
+    typedef NodesIterator ThisType;
+    typedef Node* pointer;
+    typedef Node& reference;
+
+  public:
+    NodesIterator(super I) : super(I) {}
+
+    inline reference operator*() const {
+      return super::operator->()->second;
+    }
+    inline pointer operator->() const {
+      return &super::operator->()->second;
+    }
+  };
+
+  inline NodesIterator GraphBegin(CompilationGraph* G) {
+    return NodesIterator(G->NodesMap.begin());
+  }
+
+  inline NodesIterator GraphEnd(CompilationGraph* G) {
+    return NodesIterator(G->NodesMap.end());
+  }
+
+
+  /// NodeChildIterator - Another auxiliary class needed by GraphTraits.
+  class NodeChildIterator : public bidirectional_iterator<Node, ptrdiff_t> {
+    typedef NodeChildIterator ThisType;
+    typedef Node::container_type::iterator iterator;
+
+    CompilationGraph* OwningGraph;
+    iterator EdgeIter;
+  public:
+    typedef Node* pointer;
+    typedef Node& reference;
+
+    NodeChildIterator(Node* N, iterator I) :
+      OwningGraph(N->OwningGraph), EdgeIter(I) {}
+
+    const ThisType& operator=(const ThisType& I) {
+      assert(OwningGraph == I.OwningGraph);
+      EdgeIter = I.EdgeIter;
+      return *this;
+    }
+
+    inline bool operator==(const ThisType& I) const {
+      assert(OwningGraph == I.OwningGraph);
+      return EdgeIter == I.EdgeIter;
+    }
+    inline bool operator!=(const ThisType& I) const {
+      return !this->operator==(I);
+    }
+
+    inline pointer operator*() const {
+      return &OwningGraph->getNode((*EdgeIter)->ToolName());
+    }
+    inline pointer operator->() const {
+      return this->operator*();
+    }
+
+    ThisType& operator++() { ++EdgeIter; return *this; } // Preincrement
+    ThisType operator++(int) { // Postincrement
+      ThisType tmp = *this;
+      ++*this;
+      return tmp;
+    }
+
+    inline ThisType& operator--() { --EdgeIter; return *this; }  // Predecrement
+    inline ThisType operator--(int) { // Postdecrement
+      ThisType tmp = *this;
+      --*this;
+      return tmp;
+    }
+
+  };
+}
+
+namespace llvm {
+  template <>
+  struct GraphTraits<llvmc::CompilationGraph*> {
+    typedef llvmc::CompilationGraph GraphType;
+    typedef llvmc::Node NodeType;
+    typedef llvmc::NodeChildIterator ChildIteratorType;
+
+    static NodeType* getEntryNode(GraphType* G) {
+      return &G->getNode("root");
+    }
+
+    static ChildIteratorType child_begin(NodeType* N) {
+      return ChildIteratorType(N, N->OutEdges.begin());
+    }
+    static ChildIteratorType child_end(NodeType* N) {
+      return ChildIteratorType(N, N->OutEdges.end());
+    }
+
+    typedef llvmc::NodesIterator nodes_iterator;
+    static nodes_iterator nodes_begin(GraphType *G) {
+      return GraphBegin(G);
+    }
+    static nodes_iterator nodes_end(GraphType *G) {
+      return GraphEnd(G);
+    }
+  };
+
+}
+
+#endif // LLVM_INCLUDE_COMPILER_DRIVER_COMPILATION_GRAPH_H
diff --git a/include/llvm/CompilerDriver/Error.h b/include/llvm/CompilerDriver/Error.h
new file mode 100644
index 0000000..fa678cf
--- /dev/null
+++ b/include/llvm/CompilerDriver/Error.h
@@ -0,0 +1,35 @@
+//===--- Error.h - The LLVM Compiler Driver ---------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open
+// Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  Exception classes for llvmc.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_INCLUDE_COMPILER_DRIVER_ERROR_H
+#define LLVM_INCLUDE_COMPILER_DRIVER_ERROR_H
+
+#include <stdexcept>
+
+namespace llvmc {
+
+  /// error_code - This gets thrown during the compilation process if a tool
+  /// invocation returns a non-zero exit code.
+  class error_code: public std::runtime_error {
+    int Code_;
+  public:
+    error_code (int c)
+      : std::runtime_error("Tool returned error code"), Code_(c)
+    {}
+
+    int code() const { return Code_; }
+  };
+
+}
+
+#endif // LLVM_INCLUDE_COMPILER_DRIVER_ERROR_H
diff --git a/include/llvm/CompilerDriver/Main.inc b/include/llvm/CompilerDriver/Main.inc
new file mode 100644
index 0000000..2d50c95
--- /dev/null
+++ b/include/llvm/CompilerDriver/Main.inc
@@ -0,0 +1,139 @@
+//===--- Main.inc - The LLVM Compiler Driver --------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open
+// Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This tool provides a single point of access to the LLVM
+//  compilation tools.  It has many options. To discover the options
+//  supported please refer to the tools' manual page or run the tool
+//  with the --help option.
+//
+//  This
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_INCLUDE_COMPILER_DRIVER_MAIN_INC
+#define LLVM_INCLUDE_COMPILER_DRIVER_MAIN_INC
+
+#include "llvm/CompilerDriver/CompilationGraph.h"
+#include "llvm/CompilerDriver/Error.h"
+#include "llvm/CompilerDriver/Plugin.h"
+
+#include "llvm/System/Path.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/PluginLoader.h"
+
+#include <iostream>
+#include <stdexcept>
+#include <string>
+
+namespace cl = llvm::cl;
+namespace sys = llvm::sys;
+using namespace llvmc;
+
+// Built-in command-line options.
+// External linkage here is intentional.
+
+cl::list<std::string> InputFilenames(cl::Positional, cl::desc("<input file>"),
+                                     cl::ZeroOrMore);
+cl::opt<std::string> OutputFilename("o", cl::desc("Output file name"),
+                                    cl::value_desc("file"), cl::Prefix);
+cl::list<std::string> Languages("x",
+          cl::desc("Specify the language of the following input files"),
+          cl::ZeroOrMore);
+cl::opt<bool> DryRun("dry-run",
+                     cl::desc("Only pretend to run commands"));
+cl::opt<bool> VerboseMode("v",
+                          cl::desc("Enable verbose mode"));
+
+cl::opt<bool> CheckGraph("check-graph",
+                         cl::desc("Check the compilation graph for errors"),
+                         cl::Hidden);
+cl::opt<bool> WriteGraph("write-graph",
+                         cl::desc("Write compilation-graph.dot file"),
+                         cl::Hidden);
+cl::opt<bool> ViewGraph("view-graph",
+                         cl::desc("Show compilation graph in GhostView"),
+                         cl::Hidden);
+cl::opt<bool> SaveTemps("save-temps",
+                         cl::desc("Keep temporary files"),
+                         cl::Hidden);
+
+namespace {
+  /// BuildTargets - A small wrapper for CompilationGraph::Build.
+  int BuildTargets(CompilationGraph& graph, const LanguageMap& langMap) {
+    int ret;
+    const sys::Path& tempDir = SaveTemps
+      ? sys::Path("")
+      : sys::Path(sys::Path::GetTemporaryDirectory());
+
+    try {
+      ret = graph.Build(tempDir, langMap);
+    }
+    catch(...) {
+      tempDir.eraseFromDisk(true);
+      throw;
+    }
+
+    if (!SaveTemps)
+      tempDir.eraseFromDisk(true);
+    return ret;
+  }
+}
+
+int main(int argc, char** argv) {
+  try {
+    LanguageMap langMap;
+    CompilationGraph graph;
+
+    cl::ParseCommandLineOptions
+      (argc, argv, "LLVM Compiler Driver (Work In Progress)", true);
+
+    PluginLoader Plugins;
+    Plugins.PopulateLanguageMap(langMap);
+    Plugins.PopulateCompilationGraph(graph);
+
+    if (CheckGraph) {
+      int ret = graph.Check();
+      if (!ret)
+        std::cerr << "check-graph: no errors found.\n";
+
+      return ret;
+    }
+
+    if (ViewGraph) {
+      graph.viewGraph();
+      if (!WriteGraph)
+        return 0;
+    }
+
+    if (WriteGraph) {
+      graph.writeGraph(OutputFilename.empty()
+                       ? std::string("compilation-graph.dot")
+                       : OutputFilename);
+      return 0;
+    }
+
+    if (InputFilenames.empty()) {
+      throw std::runtime_error("no input files");
+    }
+
+    return BuildTargets(graph, langMap);
+  }
+  catch(llvmc::error_code& ec) {
+    return ec.code();
+  }
+  catch(const std::exception& ex) {
+    std::cerr << argv[0] << ": " << ex.what() << '\n';
+  }
+  catch(...) {
+    std::cerr << argv[0] << ": unknown error!\n";
+  }
+  return 1;
+}
+
+#endif // LLVM_INCLUDE_COMPILER_DRIVER_MAIN_INC
diff --git a/include/llvm/CompilerDriver/Plugin.h b/include/llvm/CompilerDriver/Plugin.h
new file mode 100644
index 0000000..9f9eee3
--- /dev/null
+++ b/include/llvm/CompilerDriver/Plugin.h
@@ -0,0 +1,79 @@
+//===--- Plugin.h - The LLVM Compiler Driver --------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open
+// Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  Plugin support for llvmc.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_INCLUDE_COMPILER_DRIVER_PLUGIN_H
+#define LLVM_INCLUDE_COMPILER_DRIVER_PLUGIN_H
+
+#include "llvm/Support/Registry.h"
+
+namespace llvmc {
+
+  class LanguageMap;
+  class CompilationGraph;
+
+  /// BasePlugin - An abstract base class for all LLVMC plugins.
+  struct BasePlugin {
+
+    /// Priority - Plugin priority, useful for handling dependencies
+    /// between plugins. Plugins with lower priorities are loaded
+    /// first.
+    virtual int Priority() const { return 0; }
+
+    /// PopulateLanguageMap - The auto-generated function that fills in
+    /// the language map (map from file extensions to language names).
+    virtual void PopulateLanguageMap(LanguageMap&) const = 0;
+
+    /// PopulateCompilationGraph - The auto-generated function that
+    /// populates the compilation graph with nodes and edges.
+    virtual void PopulateCompilationGraph(CompilationGraph&) const = 0;
+
+    /// Needed to avoid a compiler warning.
+    virtual ~BasePlugin() {}
+  };
+
+  typedef llvm::Registry<BasePlugin> PluginRegistry;
+
+  template <class P>
+  struct RegisterPlugin
+    : public PluginRegistry::Add<P> {
+    typedef PluginRegistry::Add<P> Base;
+
+    RegisterPlugin(const char* Name = "Nameless",
+                   const char* Desc = "Auto-generated plugin")
+      : Base(Name, Desc) {}
+  };
+
+
+  /// PluginLoader - Helper class used by the main program for
+  /// lifetime management.
+  struct PluginLoader {
+    PluginLoader();
+    ~PluginLoader();
+
+    /// PopulateLanguageMap - Fills in the language map by calling
+    /// PopulateLanguageMap methods of all plugins.
+    void PopulateLanguageMap(LanguageMap& langMap);
+
+    /// PopulateCompilationGraph - Populates the compilation graph by
+    /// calling PopulateCompilationGraph methods of all plugins.
+    void PopulateCompilationGraph(CompilationGraph& tools);
+
+  private:
+    // noncopyable
+    PluginLoader(const PluginLoader& other);
+    const PluginLoader& operator=(const PluginLoader& other);
+  };
+
+}
+
+#endif // LLVM_INCLUDE_COMPILER_DRIVER_PLUGIN_H
diff --git a/include/llvm/CompilerDriver/Tool.h b/include/llvm/CompilerDriver/Tool.h
new file mode 100644
index 0000000..a982e2d
--- /dev/null
+++ b/include/llvm/CompilerDriver/Tool.h
@@ -0,0 +1,85 @@
+//===--- Tool.h - The LLVM Compiler Driver ----------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open
+// Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  Tool abstract base class - an interface to tool descriptions.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_INCLUDE_COMPILER_DRIVER_TOOL_H
+#define LLVM_INCLUDE_COMPILER_DRIVER_TOOL_H
+
+#include "llvm/CompilerDriver/Action.h"
+
+#include "llvm/ADT/IntrusiveRefCntPtr.h"
+#include "llvm/ADT/StringSet.h"
+#include "llvm/System/Path.h"
+
+#include <vector>
+
+namespace llvmc {
+
+  class LanguageMap;
+  typedef std::vector<llvm::sys::Path> PathVector;
+  typedef llvm::StringSet<> InputLanguagesSet;
+
+  /// Tool - A class
+  class Tool : public llvm::RefCountedBaseVPTR<Tool> {
+  public:
+
+    virtual ~Tool() {}
+
+    virtual Action GenerateAction (const PathVector& inFiles,
+                                   bool  HasChildren,
+                                   const llvm::sys::Path& TempDir,
+                                   const InputLanguagesSet& InLangs,
+                                   const LanguageMap& LangMap) const = 0;
+
+    virtual Action GenerateAction (const llvm::sys::Path& inFile,
+                                   bool  HasChildren,
+                                   const llvm::sys::Path& TempDir,
+                                   const InputLanguagesSet& InLangs,
+                                   const LanguageMap& LangMap) const = 0;
+
+    virtual const char*  Name() const = 0;
+    virtual const char** InputLanguages() const = 0;
+    virtual const char*  OutputLanguage() const = 0;
+
+    virtual bool IsJoin() const = 0;
+
+  protected:
+    /// OutFileName - Generate the output file name.
+    llvm::sys::Path OutFilename(const llvm::sys::Path& In,
+                                const llvm::sys::Path& TempDir,
+                                bool StopCompilation,
+                                const char* OutputSuffix) const;
+  };
+
+  /// JoinTool - A Tool that has an associated input file list.
+  class JoinTool : public Tool {
+  public:
+    void AddToJoinList(const llvm::sys::Path& P) { JoinList_.push_back(P); }
+    void ClearJoinList() { JoinList_.clear(); }
+    bool JoinListEmpty() const { return JoinList_.empty(); }
+
+    Action GenerateAction(bool  HasChildren,
+                          const llvm::sys::Path& TempDir,
+                          const InputLanguagesSet& InLangs,
+                          const LanguageMap& LangMap) const {
+      return GenerateAction(JoinList_, HasChildren, TempDir, InLangs, LangMap);
+    }
+    // We shouldn't shadow base class's version of GenerateAction.
+    using Tool::GenerateAction;
+
+  private:
+    PathVector JoinList_;
+  };
+
+}
+
+#endif // LLVM_INCLUDE_COMPILER_DRIVER_TOOL_H