rewrite FormatDiagnostic to be less gross and a lot more efficient.
This also makes it illegal to have bare '%'s in diagnostics.  If you
want a % in a diagnostic, use %%.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@59596 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/TextDiagnosticBuffer.cpp b/lib/Driver/TextDiagnosticBuffer.cpp
index b138b1a..5032cdb 100644
--- a/lib/Driver/TextDiagnosticBuffer.cpp
+++ b/lib/Driver/TextDiagnosticBuffer.cpp
@@ -12,6 +12,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang/Driver/TextDiagnosticBuffer.h"
+#include "llvm/ADT/SmallString.h"
 using namespace clang;
 
 /// HandleDiagnostic - Store the errors, warnings, and notes that are
@@ -19,19 +20,19 @@
 /// 
 void TextDiagnosticBuffer::HandleDiagnostic(Diagnostic::Level Level,
                                             const DiagnosticInfo &Info) {
+  llvm::SmallString<100> StrC;
+  Info.FormatDiagnostic(StrC);
+  std::string Str(StrC.begin(), StrC.end());
   switch (Level) {
   default: assert(0 && "Diagnostic not handled during diagnostic buffering!");
   case Diagnostic::Note:
-    Notes.push_back(std::make_pair(Info.getLocation().getLocation(),
-                                   FormatDiagnostic(Info)));
+    Notes.push_back(std::make_pair(Info.getLocation().getLocation(), Str));
     break;
   case Diagnostic::Warning:
-    Warnings.push_back(std::make_pair(Info.getLocation().getLocation(),
-                                      FormatDiagnostic(Info)));
+    Warnings.push_back(std::make_pair(Info.getLocation().getLocation(), Str));
     break;
   case Diagnostic::Error:
-    Errors.push_back(std::make_pair(Info.getLocation().getLocation(),
-                                    FormatDiagnostic(Info)));
+    Errors.push_back(std::make_pair(Info.getLocation().getLocation(), Str));
     break;
   }
 }
diff --git a/lib/Driver/TextDiagnosticPrinter.cpp b/lib/Driver/TextDiagnosticPrinter.cpp
index 3b8ec10..cfbe8a7 100644
--- a/lib/Driver/TextDiagnosticPrinter.cpp
+++ b/lib/Driver/TextDiagnosticPrinter.cpp
@@ -15,6 +15,7 @@
 #include "clang/Basic/SourceManager.h"
 #include "clang/Lex/Lexer.h"
 #include "llvm/Support/MemoryBuffer.h"
+#include "llvm/ADT/SmallString.h"
 using namespace clang;
 
 void TextDiagnosticPrinter::
@@ -138,13 +139,15 @@
   case Diagnostic::Warning: OS << "warning: "; break;
   case Diagnostic::Error:   OS << "error: "; break;
   case Diagnostic::Fatal:   OS << "fatal error: "; break;
-    break;
   }
   
-  OS << FormatDiagnostic(Info) << "\n";
+  llvm::SmallString<100> OutStr;
+  Info.FormatDiagnostic(OutStr);
+  OS.write(OutStr.begin(), OutStr.size());
+  OS << '\n';
   
-  if (CaretDiagnostics && Pos.isValid() && ((LastLoc != Pos) ||
-                                            Info.getNumRanges())) {
+  if (CaretDiagnostics && Pos.isValid() &&
+      ((LastLoc != Pos) || Info.getNumRanges())) {
     // Cache the LastLoc, it allows us to omit duplicate source/caret spewage.
     LastLoc = Pos;