Move the driver entry point out of Main.inc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74482 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CompilerDriver/Main.cpp b/lib/CompilerDriver/Main.cpp
new file mode 100644
index 0000000..6807a83
--- /dev/null
+++ b/lib/CompilerDriver/Main.cpp
@@ -0,0 +1,125 @@
+//===--- Main.cpp - 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.
+//
+//===----------------------------------------------------------------------===//
+//
+//  llvmc::Main function - driver entry point.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CompilerDriver/BuiltinOptions.h"
+#include "llvm/CompilerDriver/CompilationGraph.h"
+#include "llvm/CompilerDriver/Error.h"
+#include "llvm/CompilerDriver/Plugin.h"
+
+#include "llvm/System/Path.h"
+
+#include <iostream>
+#include <stdexcept>
+#include <string>
+
+namespace cl = llvm::cl;
+namespace sys = llvm::sys;
+using namespace llvmc;
+
+namespace {
+
+  sys::Path getTempDir() {
+    sys::Path tempDir;
+
+    // GCC 4.5-style -save-temps handling.
+    if (SaveTemps == SaveTempsEnum::Unset) {
+      tempDir = sys::Path::GetTemporaryDirectory();
+    }
+    else if (SaveTemps == SaveTempsEnum::Obj && !OutputFilename.empty()) {
+      tempDir = OutputFilename;
+
+      if (!tempDir.exists()) {
+        std::string ErrMsg;
+        if (tempDir.createDirectoryOnDisk(true, &ErrMsg))
+          throw std::runtime_error(ErrMsg);
+      }
+    }
+    // else if (SaveTemps == Cwd) -> use current dir (leave tempDir empty)
+
+    return tempDir;
+  }
+
+  /// BuildTargets - A small wrapper for CompilationGraph::Build.
+  int BuildTargets(CompilationGraph& graph, const LanguageMap& langMap) {
+    int ret;
+    const sys::Path& tempDir = getTempDir();
+
+    try {
+      ret = graph.Build(tempDir, langMap);
+    }
+    catch(...) {
+      if (SaveTemps == SaveTempsEnum::Unset)
+        tempDir.eraseFromDisk(true);
+      throw;
+    }
+
+    if (SaveTemps == SaveTempsEnum::Unset)
+      tempDir.eraseFromDisk(true);
+    return ret;
+  }
+}
+
+namespace llvmc {
+
+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;
+}
+
+} // end namespace llvmc