diff --git a/lib/Driver/Action.cpp b/lib/Driver/Action.cpp
new file mode 100644
index 0000000..6243489
--- /dev/null
+++ b/lib/Driver/Action.cpp
@@ -0,0 +1,79 @@
+//===--- Action.cpp - Abstract compilation steps ------------------------*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Driver/Action.h"
+
+#include <cassert>
+using namespace clang::driver;
+
+Action::~Action() {
+  // FIXME: Free the inputs. The problem is that BindArchAction shares
+  // inputs; so we can't just walk the inputs.
+}
+
+const char *Action::getClassName(ActionClass AC) {
+  switch (AC) {
+  case InputClass: return "input";
+  case BindArchClass: return "bind-arch";
+  case PreprocessJobClass: return "preprocessor";
+  case PrecompileJobClass: return "precompiler";
+  case AnalyzeJobClass: return "analyzer";
+  case CompileJobClass: return "compiler";
+  case AssembleJobClass: return "assembler";
+  case LinkJobClass: return "linker";
+  case LipoJobClass: return "lipo";
+  }
+
+  assert(0 && "invalid class");
+  return 0;
+}
+
+InputAction::InputAction(const Arg &_Input, types::ID _Type)
+  : Action(InputClass, _Type), Input(_Input) {
+}
+
+BindArchAction::BindArchAction(Action *Input, const char *_ArchName)
+  : Action(BindArchClass, Input, Input->getType()), ArchName(_ArchName) {
+}
+
+JobAction::JobAction(ActionClass Kind, Action *Input, types::ID Type)
+  : Action(Kind, Input, Type) {
+}
+
+JobAction::JobAction(ActionClass Kind, const ActionList &Inputs, types::ID Type)
+  : Action(Kind, Inputs, Type) {
+}
+
+PreprocessJobAction::PreprocessJobAction(Action *Input, types::ID OutputType)
+  : JobAction(PreprocessJobClass, Input, OutputType) {
+}
+
+PrecompileJobAction::PrecompileJobAction(Action *Input, types::ID OutputType)
+  : JobAction(PrecompileJobClass, Input, OutputType) {
+}
+
+AnalyzeJobAction::AnalyzeJobAction(Action *Input, types::ID OutputType)
+  : JobAction(AnalyzeJobClass, Input, OutputType) {
+}
+
+CompileJobAction::CompileJobAction(Action *Input, types::ID OutputType)
+  : JobAction(CompileJobClass, Input, OutputType) {
+}
+
+AssembleJobAction::AssembleJobAction(Action *Input, types::ID OutputType)
+  : JobAction(AssembleJobClass, Input, OutputType) {
+}
+
+LinkJobAction::LinkJobAction(ActionList &Inputs, types::ID Type)
+  : JobAction(LinkJobClass, Inputs, Type) {
+}
+
+LipoJobAction::LipoJobAction(ActionList &Inputs, types::ID Type)
+  : JobAction(LipoJobClass, Inputs, Type) {
+}