Improve error recovery in C++: when we hit 'implicit int' cases in C++,
these are usually because the parser was thoroughly confused.  In addition
to typing the value being declared as an int and hoping for the best, we
mark the value as invalid so we don't get chains of errors when it is
used downstream.  In C, implicit int actually is valid, so typing the thing
as int is good and marking it invalid is bad. :)


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@74266 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaType.cpp b/lib/Sema/SemaType.cpp
index 12077b0..8a0ad08 100644
--- a/lib/Sema/SemaType.cpp
+++ b/lib/Sema/SemaType.cpp
@@ -121,16 +121,18 @@
       if (DeclLoc.isInvalid())
         DeclLoc = DS.getSourceRange().getBegin();
 
-      if (getLangOptions().CPlusPlus && !getLangOptions().Microsoft)
+      if (getLangOptions().CPlusPlus && !getLangOptions().Microsoft) {
         Diag(DeclLoc, diag::err_missing_type_specifier)
           << DS.getSourceRange();
-      else
+        
+        // When this occurs in C++ code, often something is very broken with the
+        // value being declared, poison it as invalid so we don't get chains of
+        // errors.
+        isInvalid = true;
+      } else {
         Diag(DeclLoc, diag::ext_missing_type_specifier)
           << DS.getSourceRange();
-
-      // FIXME: If we could guarantee that the result would be well-formed, it
-      // would be useful to have a code insertion hint here. However, after
-      // emitting this warning/error, we often emit other errors.
+      }
     }
       
     // FALL THROUGH.