diff --git a/include/clang/Basic/DiagnosticParseKinds.td b/include/clang/Basic/DiagnosticParseKinds.td
index a040d3532a..c2e90e8da4 100644
--- a/include/clang/Basic/DiagnosticParseKinds.td
+++ b/include/clang/Basic/DiagnosticParseKinds.td
@@ -17,15 +17,15 @@ def w_asm_qualifier_ignored : Warning<"ignored %0 qualifier on asm">;
 
 def ext_empty_source_file : Extension<"ISO C forbids an empty source file">;
 def ext_top_level_semi : Extension<
-  "ISO C does not allow an extra ';' outside of a function">;
+  "extra ';' outside of a function">;
 def ext_extra_struct_semi : Extension<
-  "ISO C does not allow an extra ';' inside a struct or union">;
+  "extra ';' inside a struct or union">;
 
 def ext_duplicate_declspec : Extension<"duplicate '%0' declaration specifier">;
-def ext_plain_complex : Extension<
-  "ISO C does not support plain '_Complex' meaning '_Complex double'">;
+def ext_plain_complex : ExtWarn<
+  "plain '_Complex' requires a type specifier; assuming '_Complex double'">;
 def ext_integer_complex : Extension<
-  "ISO C does not support complex integer types">;
+  "complex integer types are an extension">;
 def ext_thread_before : Extension<"'__thread' before 'static'">;
 
 def ext_empty_struct_union_enum : Extension<"use of empty %0 extension">;
@@ -43,8 +43,8 @@ def ext_c99_variable_decl_in_for_loop : Extension<
   "variable declaration in for loop is a C99-specific feature">;
 def ext_c99_compound_literal : Extension<
   "compound literals are a C99-specific feature">;
-def ext_c99_enumerator_list_comma : Extension<
-  "commas at the end of enumerator lists are a C99-specific feature">;
+def ext_enumerator_list_comma : Extension<
+  "commas at the end of enumerator lists are a %select{C99|C++0x}0-specific feature">;
 
 def ext_gnu_indirect_goto : Extension<
   "use of GNU indirect-goto extension">;
diff --git a/include/clang/Parse/DeclSpec.h b/include/clang/Parse/DeclSpec.h
index 248d78a023..5d78192e1d 100644
--- a/include/clang/Parse/DeclSpec.h
+++ b/include/clang/Parse/DeclSpec.h
@@ -324,7 +324,7 @@ public:
   /// Finish - This does final analysis of the declspec, issuing diagnostics for
   /// things like "_Imaginary" (lacking an FP type).  After calling this method,
   /// DeclSpec is guaranteed self-consistent, even if an error occurred.
-  void Finish(Diagnostic &D, SourceManager& SrcMgr, const LangOptions &Lang);
+  void Finish(Diagnostic &D, Preprocessor &PP);
 
   /// isMissingDeclaratorOk - This checks if this DeclSpec can stand alone,
   /// without a Declarator. Only tag declspecs can stand alone.
diff --git a/lib/Parse/DeclSpec.cpp b/lib/Parse/DeclSpec.cpp
index de9f36dd9c..40675de989 100644
--- a/lib/Parse/DeclSpec.cpp
+++ b/lib/Parse/DeclSpec.cpp
@@ -13,6 +13,7 @@
 
 #include "clang/Parse/DeclSpec.h"
 #include "clang/Parse/ParseDiagnostic.h"
+#include "clang/Lex/Preprocessor.h"
 #include "clang/Basic/LangOptions.h"
 #include "llvm/ADT/STLExtras.h"
 #include <cstring>
@@ -283,9 +284,9 @@ bool DeclSpec::SetFunctionSpecExplicit(SourceLocation Loc, const char *&PrevSpec
 /// "_Imaginary" (lacking an FP type).  This returns a diagnostic to issue or
 /// diag::NUM_DIAGNOSTICS if there is no error.  After calling this method,
 /// DeclSpec is guaranteed self-consistent, even if an error occurred.
-void DeclSpec::Finish(Diagnostic &D, SourceManager& SrcMgr, 
-                      const LangOptions &Lang) {
+void DeclSpec::Finish(Diagnostic &D, Preprocessor &PP) {
   // Check the type specifier components first.
+  SourceManager &SrcMgr = PP.getSourceManager();
 
   // signed/unsigned are only valid with int/char/wchar_t.
   if (TypeSpecSign != TSS_unspecified) {
@@ -330,7 +331,10 @@ void DeclSpec::Finish(Diagnostic &D, SourceManager& SrcMgr,
   // disallow their use.  Need information about the backend.
   if (TypeSpecComplex != TSC_unspecified) {
     if (TypeSpecType == TST_unspecified) {
-      Diag(D, TSCLoc, SrcMgr, diag::ext_plain_complex);
+      Diag(D, TSCLoc, SrcMgr, diag::ext_plain_complex)
+        << CodeModificationHint::CreateInsertion(
+                              PP.getLocForEndOfToken(getTypeSpecComplexLoc()),
+                                                 " double");
       TypeSpecType = TST_double;   // _Complex -> _Complex double.
     } else if (TypeSpecType == TST_int || TypeSpecType == TST_char) {
       // Note that this intentionally doesn't include _Complex _Bool.
diff --git a/lib/Parse/ParseDecl.cpp b/lib/Parse/ParseDecl.cpp
index e233a22162..104ca0336b 100644
--- a/lib/Parse/ParseDecl.cpp
+++ b/lib/Parse/ParseDecl.cpp
@@ -496,7 +496,7 @@ void Parser::ParseDeclarationSpecifiers(DeclSpec &DS,
     DoneWithDeclSpec:
       // If this is not a declaration specifier token, we're done reading decl
       // specifiers.  First verify that DeclSpec's are consistent.
-      DS.Finish(Diags, PP.getSourceManager(), getLang());
+      DS.Finish(Diags, PP);
       return;
         
     case tok::coloncolon: // ::foo::bar
@@ -1169,7 +1169,8 @@ void Parser::ParseStructUnionBody(SourceLocation RecordLoc,
     
     // Check for extraneous top-level semicolon.
     if (Tok.is(tok::semi)) {
-      Diag(Tok, diag::ext_extra_struct_semi);
+      Diag(Tok, diag::ext_extra_struct_semi)
+        << CodeModificationHint::CreateRemoval(SourceRange(Tok.getLocation()));
       ConsumeToken();
       continue;
     }
@@ -1372,8 +1373,11 @@ void Parser::ParseEnumBody(SourceLocation StartLoc, DeclPtrTy EnumDecl) {
       break;
     SourceLocation CommaLoc = ConsumeToken();
     
-    if (Tok.isNot(tok::identifier) && !getLang().C99)
-      Diag(CommaLoc, diag::ext_c99_enumerator_list_comma);
+    if (Tok.isNot(tok::identifier) && 
+        !(getLang().C99 || getLang().CPlusPlus0x))
+      Diag(CommaLoc, diag::ext_enumerator_list_comma)
+        << getLang().CPlusPlus
+        << CodeModificationHint::CreateRemoval((SourceRange(CommaLoc)));
   }
   
   // Eat the }.
@@ -1625,7 +1629,7 @@ void Parser::ParseTypeQualifierListOpt(DeclSpec &DS, bool AttributesAllowed) {
       DoneWithTypeQuals:
       // If this is not a type-qualifier token, we're done reading type
       // qualifiers.  First verify that DeclSpec's are consistent.
-      DS.Finish(Diags, PP.getSourceManager(), getLang());
+      DS.Finish(Diags, PP);
       return;
     }
 
diff --git a/lib/Parse/ParseExprCXX.cpp b/lib/Parse/ParseExprCXX.cpp
index 5865771f60..f00edddffe 100644
--- a/lib/Parse/ParseExprCXX.cpp
+++ b/lib/Parse/ParseExprCXX.cpp
@@ -608,7 +608,7 @@ void Parser::ParseCXXSimpleTypeSpecifier(DeclSpec &DS) {
   // GNU typeof support.
   case tok::kw_typeof:
     ParseTypeofSpecifier(DS);
-    DS.Finish(Diags, PP.getSourceManager(), getLang());
+    DS.Finish(Diags, PP);
     return;
   }
   if (Tok.is(tok::annot_typename))
@@ -616,7 +616,7 @@ void Parser::ParseCXXSimpleTypeSpecifier(DeclSpec &DS) {
   else
     DS.SetRangeEnd(Tok.getLocation());
   ConsumeToken();
-  DS.Finish(Diags, PP.getSourceManager(), getLang());
+  DS.Finish(Diags, PP);
 }
 
 /// ParseCXXTypeSpecifierSeq - Parse a C++ type-specifier-seq (C++
diff --git a/lib/Parse/Parser.cpp b/lib/Parse/Parser.cpp
index 8903da29a0..5b38f60abe 100644
--- a/lib/Parse/Parser.cpp
+++ b/lib/Parse/Parser.cpp
@@ -372,7 +372,8 @@ Parser::DeclGroupPtrTy Parser::ParseExternalDeclaration() {
   DeclPtrTy SingleDecl;
   switch (Tok.getKind()) {
   case tok::semi:
-    Diag(Tok, diag::ext_top_level_semi);
+    Diag(Tok, diag::ext_top_level_semi)
+      << CodeModificationHint::CreateRemoval(SourceRange(Tok.getLocation()));
     ConsumeToken();
     // TODO: Invoke action for top-level semicolon.
     return DeclGroupPtrTy();
diff --git a/test/Sema/fixit-c90.c b/test/Sema/fixit-c90.c
new file mode 100644
index 0000000000..125e5f8f3a
--- /dev/null
+++ b/test/Sema/fixit-c90.c
@@ -0,0 +1,11 @@
+/* RUN: clang -fsyntax-only -std=c90 -pedantic %s 
+ */
+/* This is a test of the various code modification hints that are
+   provided as part of warning or extension diagnostics. Eventually,
+   we would like to actually try to perform the suggested
+   modifications and compile the result to test that no warnings
+   remain. */
+
+enum e0 {
+  e1,
+};
diff --git a/test/Sema/fixit.c b/test/Sema/fixit.c
new file mode 100644
index 0000000000..e2443cc52f
--- /dev/null
+++ b/test/Sema/fixit.c
@@ -0,0 +1,18 @@
+// RUN: clang -fsyntax-only -pedantic %s 
+
+/* This is a test of the various code modification hints that are
+   provided as part of warning or extension diagnostics. Eventually,
+   we would like to actually try to perform the suggested
+   modifications and compile the result to test that no warnings
+   remain. */
+
+void f0(void) { };
+
+struct s {
+  int x, y;;
+};
+
+_Complex cd;
+
+struct s s0 = { y: 5 };
+int array0[5] = { [3] 3 };
diff --git a/test/SemaCXX/fixit.cpp b/test/SemaCXX/fixit.cpp
new file mode 100644
index 0000000000..db0cd8ce18
--- /dev/null
+++ b/test/SemaCXX/fixit.cpp
@@ -0,0 +1,14 @@
+// RUN: clang-cc -fsyntax-only -pedantic -verify %s 
+
+/* This is a test of the various code modification hints that are
+   provided as part of warning or extension diagnostics. Eventually,
+   we would like to actually try to perform the suggested
+   modifications and compile the result to test that no warnings
+   remain. */
+
+struct C1 { };
+struct C2 : virtual public virtual C1 { }; // expected-error{{duplicate}}
+
+template<int Value> struct CT { };
+
+CT<10 >> 2> ct; // expected-warning{{require parentheses}}