Parsed keywords as argument labels correctly, fixing diagnostic regression.

Author: nate-chandler

lib/Parse/ParseDecl.cpp

@@ -2589,6 +2589,8 @@ bool Parser::isStartOfDecl() {
   // If this is obviously not the start of a decl, then we're done.
   if (!isKeywordPossibleDeclStart(Tok)) return false;
 
+  if (peekToken().is(tok::colon)) return false;
+
   // When 'init' appears inside another 'init', it's likely the user wants to
   // invoke an initializer but forgets to prefix it with 'self.' or 'super.'
   // Otherwise, expect 'init' to be the start of a declaration (and complain

lib/Parse/ParseStmt.cpp

@@ -62,6 +62,7 @@ bool Parser::isStartOfStmt() {
   case tok::pound_warning:
   case tok::pound_error:
   case tok::pound_sourceLocation:
+    if (peekToken().is(tok::colon)) return false;
     return true;
 
   case tok::pound_line:

lib/Parse/Parser.cpp

@@ -1017,7 +1017,7 @@ Parser::parseList(tok RightK, SourceLoc LeftLoc, SourceLoc &RightLoc,
     }
     // If we're in a comma-separated list, the next token is at the
     // beginning of a new line and can never start an element, break.
-    if (Tok.isAtStartOfLine() && !AllowSepOmission &&
+    if (Tok.isAtStartOfLine() && 
         (Tok.is(tok::r_brace) || isStartOfDecl() || isStartOfStmt())) {
       break;
     }

test/Parse/invalid.swift

@@ -25,11 +25,11 @@ func runAction() {} // expected-note {{'runAction' declared here}}
 
 // rdar://16601779
 func foo() {
-  runAction(SKAction.sequence() // expected-error {{use of unresolved identifier 'SKAction'; did you mean 'runAction'?}} {{13-21=runAction}}
+  runAction(SKAction.sequence() // expected-error {{use of unresolved identifier 'SKAction'; did you mean 'runAction'?}} {{13-21=runAction}} expected-note {{to match this opening '('}}
 
     skview!
     // expected-error @-1 {{use of unresolved identifier 'skview'}}
-} // expected-error {{expected expression in list of expressions}}
+} //  expected-error {{expected ')' in expression list}}
 
 super.init() // expected-error {{'super' cannot be used outside of class members}}
 

test/decl/subscript/subscripting.swift

@@ -304,10 +304,11 @@ func testSubscript1(_ s1 : SubscriptTest1) {
   // expected-error@-1 {{value of type 'SubscriptTest1' has no property or method named 'subscript'; did you mean to use the subscript operator?}}
   _ = s1.subscript("hello"
   // expected-error@-1 {{value of type 'SubscriptTest1' has no property or method named 'subscript'; did you mean to use the subscript operator?}}
+  // expected-note@-2 {{to match this opening '('}}
 
   let _ = s1["hello"]
   // expected-error@-1 {{ambiguous use of 'subscript(_:)'}}
-  // expected-error@-2 {{expected expression in list of expressions}}
+  // expected-error@-2 {{expected ')' in expression list}}
 }
 
 struct SubscriptTest2 {

validation-test/Sema/type_checker_crashers_fixed/rdar45470505.swift

@@ -5,10 +5,11 @@ extension BinaryInteger {
 
   init<S: Sequence>(bytes: S) where S.Iterator.Element == UInt8 {
     self.init(bytes // expected-error {{ambiguous reference to initializer 'init(_:)'}}
+// expected-note@-1 {{}}
 
 extension
 // expected-error@-1 {{declaration is only valid at file scope}}
-// expected-error@-2 {{expected expression in list of expressions}}
+// expected-error@-2 {{expected ')' in expression list}}
 // expected-error@-3 {{expected '{' in extension}}
   }
 // expected-error@-1 {{expected type name in extension declaration}}