Minor changes to keyword-as-identifier diagnostics

- Remove stray newline
- Adjust wording when recommending backticks for a keyword identifier
- Provide fix-it when encountering a keyword as an identifier

rdar://problem/25761380

Author: bitjammer

include/swift/AST/DiagnosticsParse.def

@@ -662,7 +662,7 @@ ERROR(expected_pattern,PointsToFirstBadToken,
 ERROR(keyword_cant_be_identifier,none,
       "keyword '%0' cannot be used as an identifier here", (StringRef))
 NOTE(backticks_to_escape,none,
-     "backticks can escape this name if it is important to use", ())
+     "if this name is unavoidable, use backticks to escape it", ())
 ERROR(expected_rparen_tuple_pattern_list,none,
       "expected ')' at end of tuple pattern", ())
 ERROR(untyped_pattern_ellipsis,none,

lib/Parse/ParseDecl.cpp

@@ -1,4 +1,3 @@
-
 //===--- ParseDecl.cpp - Swift Language Parser for Declarations -----------===//
 //
 // This source file is part of the Swift.org open source project

lib/Parse/ParsePattern.cpp

@@ -824,7 +824,8 @@ ParserResult<Pattern> Parser::parsePattern() {
     if (Tok.isKeyword() &&
         (peekToken().is(tok::colon) || peekToken().is(tok::equal))) {
       diagnose(Tok, diag::keyword_cant_be_identifier, Tok.getText());
-      diagnose(Tok, diag::backticks_to_escape);
+      diagnose(Tok, diag::backticks_to_escape)
+        .fixItReplace(Tok.getLoc(), "`" + Tok.getText().str() + "`");
       SourceLoc Loc = Tok.getLoc();
       consumeToken();
       return makeParserErrorResult(new (Context) AnyPattern(Loc));

lib/Parse/Parser.cpp

@@ -603,7 +603,8 @@ bool Parser::parseAnyIdentifier(Identifier &Result, SourceLoc &Loc,
 
   if (Tok.isKeyword()) {
     diagnose(Tok, diag::keyword_cant_be_identifier, Tok.getText());
-    diagnose(Tok, diag::backticks_to_escape);
+    diagnose(Tok, diag::backticks_to_escape)
+      .fixItReplace(Tok.getLoc(), "`" + Tok.getText().str() + "`");
   } else {
     diagnose(Tok, D);
   }

test/Parse/invalid.swift

@@ -92,8 +92,8 @@ class VarTester {
 
 func repeat() {}
 // expected-error @-1 {{keyword 'repeat' cannot be used as an identifier here}}
-// expected-note @-2 {{backticks can escape this name if it is important to use}}
+// expected-note @-2 {{if this name is unavoidable, use backticks to escape it}} {{6-12=`repeat`}}
 
 let for = 2
 // expected-error @-1 {{keyword 'for' cannot be used as an identifier here}}
-// expected-note @-2 {{backticks can escape this name if it is important to use}}
+// expected-note @-2 {{if this name is unavoidable, use backticks to escape it}} {{5-8=`for`}}

test/decl/ext/extensions.swift

@@ -49,8 +49,8 @@ extension S1.NestedStruct {} // no-error
 struct S1_2 {
   // expected-error @+4 {{type member may not be named 'Type', since it would conflict with the 'foo.Type' expression}}
   // expected-error @+3 {{type member may not be named 'Type', since it would conflict with the 'foo.Type' expression}}
-  // expected-note @+2 {{backticks can escape this name if it is important to use}} {{8-12=`Type`}}
-  // expected-note @+1 {{backticks can escape this name if it is important to use}} {{8-12=`Type`}}
+  // expected-note @+2 {{if this name is unavoidable, use backticks to escape it}} {{8-12=`Type`}}
+  // expected-note @+1 {{if this name is unavoidable, use backticks to escape it}} {{8-12=`Type`}}
   enum Type {}
 }
 struct S1_3 {

test/decl/import/import.swift

@@ -45,10 +45,10 @@ import struct Swift.nonexistent // expected-error {{no such decl in module}}
 
 import Swift.import.abc // expected-error {{expected identifier in import declaration}}
 // expected-error @-1 {{keyword 'import' cannot be used as an identifier here}}
-// expected-note @-2 {{backticks can escape this name if it is important to use}}
+// expected-note @-2 {{if this name is unavoidable, use backticks to escape it}}
 import where Swift.Int // expected-error {{expected identifier}}
 // expected-error @-1 {{keyword 'where' cannot be used as an identifier here}}
-// expected-note @-2 {{backticks can escape this name if it is important to use}}
+// expected-note @-2 {{if this name is unavoidable, use backticks to escape it}}
 import 2 // expected-error {{expected identifier}}
 
 import really.nonexistent // expected-error {{no such module 'really.nonexistent'}}

test/decl/nested.swift

@@ -198,8 +198,8 @@ func outerGenericFunction<T>(_ t: T) {
 struct S1 {
   // expected-error @+4 {{type member may not be named 'Type', since it would conflict with the 'foo.Type' expression}}
   // expected-error @+3 {{type member may not be named 'Type', since it would conflict with the 'foo.Type' expression}}
-  // expected-note @+2 {{backticks can escape this name if it is important to use}} {{8-12=`Type`}}
-  // expected-note @+1 {{backticks can escape this name if it is important to use}} {{8-12=`Type`}}
+  // expected-note @+2 {{if this name is unavoidable, use backticks to escape it}} {{8-12=`Type`}}
+  // expected-note @+1 {{if this name is unavoidable, use backticks to escape it}} {{8-12=`Type`}}
   enum Type {
     case A
   }

test/decl/overload.swift

@@ -301,11 +301,11 @@ enum EnumWithMutating {
 // https://twitter.com/jadengeller/status/619989059046240256
 protocol r21783216a {
   // expected-error @+2 {{type member may not be named 'Type', since it would conflict with the 'foo.Type' expression}}
-  // expected-note @+1 {{backticks can escape this name if it is important to use}} {{18-22=`Type`}}
+  // expected-note @+1 {{if this name is unavoidable, use backticks to escape it}} {{18-22=`Type`}}
   associatedtype Type
 
   // expected-error @+2 {{type member may not be named 'Protocol', since it would conflict with the 'foo.Protocol' expression}}
-  // expected-note @+1 {{backticks can escape this name if it is important to use}} {{18-26=`Protocol`}}
+  // expected-note @+1 {{if this name is unavoidable, use backticks to escape it}} {{18-26=`Protocol`}}
   associatedtype Protocol
 }
 

test/decl/var/variables.swift

@@ -15,7 +15,7 @@ var bfx : Int, bfy : Int
 _ = 10
 
 func _(_ x: Int) {} // expected-error {{keyword '_' cannot be used as an identifier here}}
-// expected-note @-1 {{backticks can escape this name if it is important to use}}
+// expected-note @-1 {{if this name is unavoidable, use backticks to escape it}}
 
 
 var self1 = self1 // expected-error {{variable used within its own initial value}}