Add 'diagtool' to the 'tools/' directory. diagtool is a new tool (WIP) for analyzing and working with clang diagnostics.

Some interesting stats from 'diagtool list-warnings' on the current version of clang:

  Percentage of warnings with flags: 48.79%
  Number of unique flags: 148
  Average number of diagnostics per flag: 2.041

llvm-svn: 137109

1 files changed, 26 insertions, 0 deletions

diff --git a/clang/tools/diagtool/diagtool_main.cpp b/clang/tools/diagtool/diagtool_main.cpp
new file mode 100644
index 00000000000..66a73e947a1
--- /dev/null
+++ b/clang/tools/diagtool/diagtool_main.cpp
@@ -0,0 +1,26 @@
+//===- diagtool_main.h - Entry point for invoking all diagnostic tools ----===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the main function for diagtool.
+//
+//===----------------------------------------------------------------------===//
+
+#include "DiagTool.h"
+
+using namespace diagtool;
+
+int main(int argc, char *argv[]) {
+  if (argc > 1)
+    if (DiagTool *tool = diagTools.getTool(argv[1]))
+      return tool->run(argc - 1, &argv[2], llvm::errs());
+
+  llvm::errs() << "usage: diagtool <command> [<args>]\n\n";
+  diagTools.printCommands(llvm::errs());
+  return 1;    
+}