[Parse] Upgrade @noescape/@autoclosure(escaping) warnings to Swift 4 errors.

Part of rdar://problem/28961650 .

Author: huonw

include/swift/AST/DiagnosticsParse.def

@@ -1314,12 +1314,18 @@ ERROR(attr_noescape_conflicts_escaping_autoclosure,none,
 ERROR(attr_noescape_implied_by_autoclosure,none,
       "@noescape is implied by @autoclosure and should not be "
       "redundantly specified", ())
-WARNING(attr_autoclosure_escaping_deprecated,none,
+WARNING(swift3_attr_autoclosure_escaping_deprecated,none,
         "@autoclosure(escaping) is deprecated; use @autoclosure @escaping instead",
         ())
-WARNING(attr_noescape_deprecated,none,
+ERROR(attr_autoclosure_escaping_deprecated,none,
+      "@autoclosure(escaping) has been removed; use @autoclosure @escaping instead",
+      ())
+WARNING(swift3_attr_noescape_deprecated,none,
         "@noescape is the default and is deprecated",
         ())
+ERROR(attr_noescape_deprecated,none,
+      "@noescape is the default and has been removed",
+      ())
 
 // convention
 ERROR(convention_attribute_expected_lparen,none,

lib/Parse/ParseDecl.cpp

@@ -1647,7 +1647,9 @@ bool Parser::parseTypeAttribute(TypeAttributes &Attributes, bool justChecking) {
       if (Attributes.has(TAK_noescape)) {
         diagnose(Loc, diag::attr_noescape_conflicts_escaping_autoclosure);
       } else {
-        diagnose(Loc, diag::attr_autoclosure_escaping_deprecated)
+        diagnose(Loc, Context.isSwiftVersion3()
+                          ? diag::swift3_attr_autoclosure_escaping_deprecated
+                          : diag::attr_autoclosure_escaping_deprecated)
             .fixItReplace(autoclosureEscapingParenRange, " @escaping ");
       }
       Attributes.setAttr(TAK_escaping, Loc);
@@ -1669,8 +1671,10 @@ bool Parser::parseTypeAttribute(TypeAttributes &Attributes, bool justChecking) {
     }
 
     // @noescape is deprecated and no longer used
-    diagnose(Loc, diag::attr_noescape_deprecated)
-      .fixItRemove({Attributes.AtLoc,Loc});
+    diagnose(Loc, Context.isSwiftVersion3()
+                      ? diag::swift3_attr_noescape_deprecated
+                      : diag::attr_noescape_deprecated)
+        .fixItRemove({Attributes.AtLoc, Loc});
 
     break;
   case TAK_escaping:

test/attr/attr_escaping.swift

@@ -6,7 +6,7 @@ func paramDeclEscaping(@escaping fn: (Int) -> Void) {} // expected-error {{attri
 func wrongParamType(a: @escaping Int) {} // expected-error {{@escaping attribute only applies to function types}}
 
 func conflictingAttrs(_ fn: @noescape @escaping () -> Int) {} // expected-error {{@escaping conflicts with @noescape}}
- // expected-warning@-1{{@noescape is the default and is deprecated}} {{29-39=}}
+ // expected-error@-1{{@noescape is the default and has been removed}} {{29-39=}}
 
 func takesEscaping(_ fn: @escaping () -> Int) {} // ok