When we encounter a '==' in a context expecting a '=', assume the user made a typo:

t.c:1:7: error: invalid '==' at end of declaration; did you mean '='?
int x == 0;
      ^~
      =

Implements rdar://8488464.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@116035 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Parse/ParseDecl.cpp b/lib/Parse/ParseDecl.cpp
index 89b4182..e6a4b91 100644
--- a/lib/Parse/ParseDecl.cpp
+++ b/lib/Parse/ParseDecl.cpp
@@ -594,7 +594,8 @@
   }
 
   // Parse declarator '=' initializer.
-  if (Tok.is(tok::equal)) {
+  if (isTokenEqualOrMistypedEqualEqual(
+                               diag::err_invalid_equalequal_after_declarator)) {
     ConsumeToken();
     if (Tok.is(tok::kw_delete)) {
       SourceLocation DelLoc = ConsumeToken();
diff --git a/lib/Parse/ParseExprCXX.cpp b/lib/Parse/ParseExprCXX.cpp
index e8b921b..77cb449 100644
--- a/lib/Parse/ParseExprCXX.cpp
+++ b/lib/Parse/ParseExprCXX.cpp
@@ -821,9 +821,10 @@
                                                                 DeclaratorInfo);
   DeclOut = Dcl.get();
   ExprOut = ExprError();
-  
+
   // '=' assignment-expression
-  if (Tok.is(tok::equal)) {
+  if (isTokenEqualOrMistypedEqualEqual(
+                               diag::err_invalid_equalequal_after_declarator)) {
     SourceLocation EqualLoc = ConsumeToken();
     ExprResult AssignExpr(ParseAssignmentExpression());
     if (!AssignExpr.isInvalid()) 
diff --git a/lib/Parse/Parser.cpp b/lib/Parse/Parser.cpp
index 33c7b7d..8084088 100644
--- a/lib/Parse/Parser.cpp
+++ b/lib/Parse/Parser.cpp
@@ -1156,6 +1156,20 @@
   return false;
 }
 
+bool Parser::isTokenEqualOrMistypedEqualEqual(unsigned DiagID) {
+  if (Tok.is(tok::equalequal)) {
+    // We have '==' in a context that we would expect a '='.
+    // The user probably made a typo, intending to type '='. Emit diagnostic,
+    // fixit hint to turn '==' -> '=' and continue as if the user typed '='.
+    Diag(Tok, DiagID)
+      << FixItHint::CreateReplacement(SourceRange(Tok.getLocation()),
+                                      getTokenSimpleSpelling(tok::equal));
+    return true;
+  }
+
+  return Tok.is(tok::equal);
+}
+
 void Parser::CodeCompletionRecovery() {
   for (Scope *S = getCurScope(); S; S = S->getParent()) {
     if (S->getFlags() & Scope::FnScope) {