Fix a couple of bugs, add some new cool stuff.

1. Fix a todo in Parser::ParseTag, to recover better.  On code like
   that in test/Sema/decl-invalid.c it causes us to return a single
   error instead of multiple.
2. Fix an error in Sema::ParseDeclarator, where it would crash if the
   declarator didn't have an identifier.  Instead, diagnose the problem.
3. Start adding infrastructure to track the range of locations covered
   by a declspec or declarator.  This is mostly implemented for declspec,
   but could be improved, it is missing for declarator.

Thanks to Neil for pointing out this crash.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@40482 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Driver/TextDiagnostics.h b/Driver/TextDiagnostics.h
new file mode 100644
index 0000000..faf1b41
--- /dev/null
+++ b/Driver/TextDiagnostics.h
@@ -0,0 +1,53 @@
+//===--- TextDiagnostics.h - Text Diagnostics Checkers ----------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Bill Wendling and is distributed under the
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This is the parent class for all text diagnostics.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef TEXT_DIAGNOSTICS_H_
+#define TEXT_DIAGNOSTICS_H_
+
+#include "clang/Basic/Diagnostic.h"
+
+namespace clang {
+class SourceManager;
+class HeaderSearch;
+class Preprocessor;
+
+class TextDiagnostics : public DiagnosticClient {
+  HeaderSearch *TheHeaderSearch;
+protected:
+  SourceManager &SourceMgr;
+  Preprocessor *ThePreprocessor;
+
+  std::string FormatDiagnostic(Diagnostic::Level Level,
+                               diag::kind ID,
+                               const std::string *Strs,
+                               unsigned NumStrs);
+public:
+  TextDiagnostics(SourceManager &sourceMgr) : SourceMgr(sourceMgr) {}
+  virtual ~TextDiagnostics();
+
+  void setHeaderSearch(HeaderSearch &HS) { TheHeaderSearch = &HS; }
+  void setPreprocessor(Preprocessor &P) { ThePreprocessor = &P; }
+
+  virtual bool IgnoreDiagnostic(Diagnostic::Level Level, 
+                                SourceLocation Pos);
+  virtual void HandleDiagnostic(Diagnostic::Level DiagLevel,
+                                SourceLocation Pos,
+                                diag::kind ID, const std::string *Strs,
+                                unsigned NumStrs,
+                                const SourceRange *Ranges, 
+                                unsigned NumRanges) = 0;
+};
+
+} // end namspace clang
+
+#endif