llvm-vtabledump: A vtable dumper

This tool's job is to dump the vtables inside object files.  It is
currently limited to MS ABI vf- and vb-tables but it will eventually
support Itanium-style v-tables as well.

Differential Revision: http://reviews.llvm.org/D4584

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213903 91177308-0d34-0410-b5e6-96231b3b80d8

tools/llvm-vtabledump/Error.cpp

@@ -0,0 +1,43 @@
+//===- Error.cpp - system_error extensions for llvm-vtabledump --*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This defines a new error_category for the llvm-vtabledump tool.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Error.h"
+#include "llvm/Support/ErrorHandling.h"
+
+using namespace llvm;
+
+namespace {
+class vtabledump_error_category : public std::error_category {
+public:
+  const char *name() const LLVM_NOEXCEPT override { return "llvm.vtabledump"; }
+  std::string message(int ev) const override {
+    switch (static_cast<vtabledump_error>(ev)) {
+    case vtabledump_error::success:
+      return "Success";
+    case vtabledump_error::file_not_found:
+      return "No such file.";
+    case vtabledump_error::unrecognized_file_format:
+      return "Unrecognized file type.";
+    }
+    llvm_unreachable(
+        "An enumerator of vtabledump_error does not have a message defined.");
+  }
+};
+} // namespace
+
+namespace llvm {
+const std::error_category &vtabledump_category() {
+  static vtabledump_error_category o;
+  return o;
+}
+} // namespace llvm