[Parse] Add fix-its for empty Swift 2 operator decl braces. (swiftlang#4309)

And improve the error message for non-empty braces; if we're going to
ignore the contents, we should at least point you in the right
direction for Swift 3.

rdar://problem/27576922
(cherry picked from commit 3d005f3)

Author: jrose-apple

include/swift/AST/DiagnosticsParse.def

@@ -381,6 +381,9 @@ ERROR(identifier_when_expecting_operator,PointsToFirstBadToken,
 
 WARNING(deprecated_operator_body,PointsToFirstBadToken,
         "operator should no longer be declared with body", ())
+WARNING(deprecated_operator_body_use_group,PointsToFirstBadToken,
+        "operator should no longer be declared with body; "
+        "use a precedence group instead", ())
 ERROR(operator_decl_no_fixity,none,
       "operator must be declared as 'prefix', 'postfix', or 'infix'", ())
 

lib/FrontendTool/FrontendTool.cpp

@@ -647,7 +647,8 @@ class JSONFixitWriter : public DiagnosticConsumer {
         Info.ID == diag::any_as_anyobject_fixit.ID ||
         Info.ID == diag::deprecated_protocol_composition.ID ||
         Info.ID == diag::deprecated_protocol_composition_single.ID ||
-        Info.ID == diag::deprecated_any_composition.ID)
+        Info.ID == diag::deprecated_any_composition.ID ||
+        Info.ID == diag::deprecated_operator_body.ID)
       return true;
 
     return false;

lib/Parse/ParseDecl.cpp

@@ -5586,9 +5586,15 @@ Parser::parseDeclOperator(ParseDeclOptions Flags, DeclAttributes &Attributes) {
 ParserResult<OperatorDecl>
 Parser::parseDeclPrefixOperator(SourceLoc OperatorLoc, Identifier Name,
                                 SourceLoc NameLoc, DeclAttributes &Attributes) {
-  SourceLoc LBraceLoc;
-  if (consumeIf(tok::l_brace, LBraceLoc)) {
-    diagnose(LBraceLoc, diag::deprecated_operator_body);
+  SourceLoc lBraceLoc;
+  if (consumeIf(tok::l_brace, lBraceLoc)) {
+    auto Diag = diagnose(lBraceLoc, diag::deprecated_operator_body);
+    if (Tok.is(tok::r_brace)) {
+      SourceLoc lastGoodLocEnd = Lexer::getLocForEndOfToken(SourceMgr,
+                                                            NameLoc);
+      SourceLoc rBraceEnd = Lexer::getLocForEndOfToken(SourceMgr, Tok.getLoc());
+      Diag.fixItRemoveChars(lastGoodLocEnd, rBraceEnd);
+    }
 
     skipUntilDeclRBrace();
     (void) consumeIf(tok::r_brace);
@@ -5604,9 +5610,15 @@ ParserResult<OperatorDecl>
 Parser::parseDeclPostfixOperator(SourceLoc OperatorLoc,
                                  Identifier Name, SourceLoc NameLoc,
                                  DeclAttributes &Attributes) {
-  SourceLoc lbraceLoc;
-  if (consumeIf(tok::l_brace, lbraceLoc)) {
-    diagnose(lbraceLoc, diag::deprecated_operator_body);
+  SourceLoc lBraceLoc;
+  if (consumeIf(tok::l_brace, lBraceLoc)) {
+    auto Diag = diagnose(lBraceLoc, diag::deprecated_operator_body);
+    if (Tok.is(tok::r_brace)) {
+      SourceLoc lastGoodLocEnd = Lexer::getLocForEndOfToken(SourceMgr,
+                                                            NameLoc);
+      SourceLoc rBraceEnd = Lexer::getLocForEndOfToken(SourceMgr, Tok.getLoc());
+      Diag.fixItRemoveChars(lastGoodLocEnd, rBraceEnd);
+    }
 
     skipUntilDeclRBrace();
     (void) consumeIf(tok::r_brace);
@@ -5631,9 +5643,20 @@ Parser::parseDeclInfixOperator(SourceLoc operatorLoc, Identifier name,
     }
   }
 
-  SourceLoc lbraceLoc;
-  if (consumeIf(tok::l_brace, lbraceLoc)) {
-    diagnose(lbraceLoc, diag::deprecated_operator_body);
+  SourceLoc lBraceLoc;
+  if (consumeIf(tok::l_brace, lBraceLoc)) {
+    if (Tok.is(tok::r_brace)) {
+      SourceLoc lastGoodLoc = precedenceGroupNameLoc;
+      if (lastGoodLoc.isInvalid())
+        lastGoodLoc = nameLoc;
+      SourceLoc lastGoodLocEnd = Lexer::getLocForEndOfToken(SourceMgr,
+                                                            lastGoodLoc);
+      SourceLoc rBraceEnd = Lexer::getLocForEndOfToken(SourceMgr, Tok.getLoc());
+      diagnose(lBraceLoc, diag::deprecated_operator_body)
+        .fixItRemoveChars(lastGoodLocEnd, rBraceEnd);
+    } else {
+      diagnose(lBraceLoc, diag::deprecated_operator_body_use_group);
+    }
 
     skipUntilDeclRBrace();
     (void) consumeIf(tok::r_brace);

test/FixCode/fixits-apply.swift

@@ -259,3 +259,5 @@ func testProtocolCompositionSyntax() {
 
 func disable_unnamed_param_reorder(p: Int, _: String) {}
 disable_unnamed_param_reorder(0, "") // no change.
+
+prefix operator ***** {}

test/FixCode/fixits-apply.swift.result

@@ -262,3 +262,5 @@ func testProtocolCompositionSyntax() {
 
 func disable_unnamed_param_reorder(p: Int, _: String) {}
 disable_unnamed_param_reorder(0, "") // no change.
+
+prefix operator *****

test/Parse/operator_decl.swift

@@ -1,8 +1,12 @@
 // RUN: %target-parse-verify-swift
 
-prefix operator +++ {} // expected-warning {{operator should no longer be declared with body}}
-postfix operator +++ {} // expected-warning {{operator should no longer be declared with body}}
-infix operator +++ {} // expected-warning {{operator should no longer be declared with body}}
+prefix operator +++ {} // expected-warning {{operator should no longer be declared with body}} {{20-23=}}
+postfix operator +++ {} // expected-warning {{operator should no longer be declared with body}} {{21-24=}}
+infix operator +++ {} // expected-warning {{operator should no longer be declared with body}} {{19-22=}}
+infix operator +++* { // expected-warning {{operator should no longer be declared with body; use a precedence group instead}} {{none}}
+  associativity right
+}
+infix operator +++** : A { } // expected-warning {{operator should no longer be declared with body}} {{25-29=}}
 
 prefix operator // expected-error {{expected operator name in operator declaration}}