diff --git a/include/llvm/Support/SourceMgr.h b/include/llvm/Support/SourceMgr.h
index 23044a8..0260d2d 100644
--- a/include/llvm/Support/SourceMgr.h
+++ b/include/llvm/Support/SourceMgr.h
@@ -7,9 +7,9 @@
 //
 //===----------------------------------------------------------------------===//
 //
-// This file declares the SourceMgr class.  This class is used as a simple
-// substrate for diagnostics, #include handling, and other low level things for
-// simple parsers.
+// This file declares the SMLoc, SMDiagnostic and SourceMgr classes.  This
+// provides a simple substrate for diagnostics, #include handling, and other low
+// level things for simple parsers.
 //
 //===----------------------------------------------------------------------===//
 
@@ -23,6 +23,8 @@
 namespace llvm {
   class MemoryBuffer;
   class SourceMgr;
+  class SMDiagnostic;
+  class raw_ostream;
   
 class SMLoc {
   const char *Ptr;
@@ -44,8 +46,8 @@
   }
 };
 
-/// SourceMgr - This owns the files read by tblgen, handles include stacks,
-/// and handles printing of diagnostics.
+/// SourceMgr - This owns the files read by a parser, handles include stacks,
+/// and handles diagnostic wrangling.
 class SourceMgr {
   struct SrcBuffer {
     /// Buffer - The memory buffer for the file.
@@ -117,7 +119,35 @@
   void PrintMessage(SMLoc Loc, const std::string &Msg, const char *Type) const;
   
 private:
-  void PrintIncludeStack(SMLoc IncludeLoc) const;
+  void PrintIncludeStack(SMLoc IncludeLoc, raw_ostream &OS) const;
+};
+
+  
+/// SMDiagnostic - Instances of this class encapsulate one diagnostic report,
+/// allowing printing to a raw_ostream as a caret diagnostic.
+class SMDiagnostic {
+  std::string Filename;
+  int LineNo, ColumnNo;
+  std::string Message, LineContents;
+public:
+  SMDiagnostic() : LineNo(0), ColumnNo(0) {}
+  SMDiagnostic(const std::string &FN, int Line, int Col,
+               const std::string &Msg, const std::string &LineStr)
+    : Filename(FN), LineNo(Line), ColumnNo(Col), Message(Msg),
+      LineContents(LineStr) {}
+  SMDiagnostic(const SMDiagnostic &RHS) {
+    operator=(RHS);
+  }
+
+  void operator=(const SMDiagnostic &E) {
+    Filename = E.Filename;
+    LineNo = E.LineNo;
+    ColumnNo = E.ColumnNo;
+    Message = E.Message;
+    LineContents = E.LineContents;
+  }
+
+  void Print(const char *ProgName, raw_ostream &S);
 };
   
 }  // end llvm namespace
diff --git a/lib/Support/SourceMgr.cpp b/lib/Support/SourceMgr.cpp
index 6232265..123531e 100644
--- a/lib/Support/SourceMgr.cpp
+++ b/lib/Support/SourceMgr.cpp
@@ -76,17 +76,17 @@
   return LineNo;
 }
 
-void SourceMgr::PrintIncludeStack(SMLoc IncludeLoc) const {
+void SourceMgr::PrintIncludeStack(SMLoc IncludeLoc, raw_ostream &OS) const {
   if (IncludeLoc == SMLoc()) return;  // Top of stack.
   
   int CurBuf = FindBufferContainingLoc(IncludeLoc);
   assert(CurBuf != -1 && "Invalid or unspecified location!");
 
-  PrintIncludeStack(getBufferInfo(CurBuf).IncludeLoc);
+  PrintIncludeStack(getBufferInfo(CurBuf).IncludeLoc, OS);
   
-  errs() << "Included from "
-         << getBufferInfo(CurBuf).Buffer->getBufferIdentifier()
-         << ":" << FindLineNumber(IncludeLoc, CurBuf) << ":\n";
+  OS << "Included from "
+     << getBufferInfo(CurBuf).Buffer->getBufferIdentifier()
+     << ":" << FindLineNumber(IncludeLoc, CurBuf) << ":\n";
 }
 
 
@@ -99,19 +99,11 @@
   int CurBuf = FindBufferContainingLoc(Loc);
   assert(CurBuf != -1 && "Invalid or unspecified location!");
   
-  PrintIncludeStack(getBufferInfo(CurBuf).IncludeLoc);
+  PrintIncludeStack(getBufferInfo(CurBuf).IncludeLoc, OS);
   
   MemoryBuffer *CurMB = getBufferInfo(CurBuf).Buffer;
   
   
-  OS << CurMB->getBufferIdentifier() << ":"
-     << FindLineNumber(Loc, CurBuf) << ": ";
-
-  if (Type)
-    OS << Type << ": ";
-
-  OS << Msg << "\n";
-  
   // Scan backward to find the start of the line.
   const char *LineStart = Loc.getPointer();
   while (LineStart != CurMB->getBufferStart() && 
@@ -122,10 +114,51 @@
   while (LineEnd != CurMB->getBufferEnd() && 
          LineEnd[0] != '\n' && LineEnd[0] != '\r')
     ++LineEnd;
+  
+  std::string PrintedMsg;
+  if (Type) {
+    PrintedMsg = Type;
+    PrintedMsg += ": ";
+  }
+  PrintedMsg += Msg;
+  
+  
   // Print out the line.
-  OS << std::string(LineStart, LineEnd) << "\n";
-  // Print out spaces before the caret.
-  for (const char *Pos = LineStart; Pos != Loc.getPointer(); ++Pos)
-    OS << (*Pos == '\t' ? '\t' : ' ');
-  OS << "^\n";
+  SMDiagnostic(CurMB->getBufferIdentifier(), FindLineNumber(Loc, CurBuf),
+               Loc.getPointer()-LineStart, PrintedMsg,
+               std::string(LineStart, LineEnd)).Print(0, OS);
+  
 }
+
+//===----------------------------------------------------------------------===//
+// SMDiagnostic Implementation
+//===----------------------------------------------------------------------===//
+
+void SMDiagnostic::Print(const char *ProgName, raw_ostream &S) {
+  if (ProgName && ProgName[0])
+    S << ProgName << ": ";
+
+  if (Filename == "-")
+    S << "<stdin>";
+  else
+    S << Filename;
+  
+  if (LineNo != -1) {
+    S << ':' << LineNo;
+    if (ColumnNo != -1)
+      S << ':' << (ColumnNo+1);
+  }
+  
+  S << ": " << Message << '\n';
+  
+  if (LineNo != -1 && ColumnNo != -1) {
+    S << LineContents << '\n';
+    
+    // Print out spaces/tabs before the caret.
+    for (unsigned i = 0; i != unsigned(ColumnNo); ++i)
+      S << (LineContents[i] == '\t' ? '\t' : ' ');
+    S << "^\n";
+  }
+}
+
+