Put patch syntax warning behind a flag

runtime/vm/parser.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/parser.h"
 #include "vm/flags.h"
 
 #ifndef DART_PRECOMPILED_RUNTIME
 
 #include "lib/invocation_mirror.h"
@@ skipping 34 matching lines @@
 DEFINE_FLAG(bool, trace_parser, false, "Trace parser operations.");
 DEFINE_FLAG(bool, warn_mixin_typedef, true, "Warning on legacy mixin typedef.");
 // TODO(floitsch): remove the conditional-directive flag, once we publicly
 // committed to the current version.
 DEFINE_FLAG(bool, conditional_directives, true,
     "Enable conditional directives");
 DEFINE_FLAG(bool, initializing_formal_access, false,
     "Make initializing formal parameters visible in initializer list.");
 DEFINE_FLAG(bool, warn_super, false,
     "Warning if super initializer not last in initializer list.");
+DEFINE_FLAG(bool, warn_patch, false, "Warn on old-style patch syntax.");
 DEFINE_FLAG(bool, await_is_keyword, false,
     "await and yield are treated as proper keywords in synchronous code.");
 
 DECLARE_FLAG(bool, profile_vm);
 DECLARE_FLAG(bool, trace_service);
 
 // Quick access to the current thread, isolate and zone.
 #define T (thread())
 #define I (isolate())
 #define Z (zone())
@@ skipping 4481 matching lines @@
   bool is_abstract = false;
   TokenPosition declaration_pos =
     metadata_pos.IsReal() ? metadata_pos : TokenPos();
   if (is_patch_source() && IsPatchAnnotation(metadata_pos)) {
     is_patch = true;
     metadata_pos = TokenPosition::kNoSource;
     declaration_pos = TokenPos();
   } else if (is_patch_source() &&
       (CurrentToken() == Token::kIDENT) &&
       CurrentLiteral()->Equals("patch")) {
-    ReportWarning("deprecated use of patch 'keyword'");
+    if (FLAG_warn_patch) {
+      ReportWarning("deprecated use of patch 'keyword'");
+    }
     ConsumeToken();
     is_patch = true;
   } else if (CurrentToken() == Token::kABSTRACT) {
     is_abstract = true;
     ConsumeToken();
   }
   ExpectToken(Token::kCLASS);
   const TokenPosition classname_pos = TokenPos();
   String& class_name = *ExpectUserDefinedTypeIdentifier("class name expected");
   if (FLAG_trace_parser) {
@@ skipping 1057 matching lines @@
   const bool is_static = true;
   bool is_external = false;
   bool is_patch = false;
   if (is_patch_source() && IsPatchAnnotation(metadata_pos)) {
     is_patch = true;
     metadata_pos = TokenPosition::kNoSource;
   } else if (is_patch_source() &&
       (CurrentToken() == Token::kIDENT) &&
       CurrentLiteral()->Equals("patch") &&
       (LookaheadToken(1) != Token::kLPAREN)) {
-    ReportWarning("deprecated use of patch 'keyword'");
+    if (FLAG_warn_patch) {
+      ReportWarning("deprecated use of patch 'keyword'");
+    }
     ConsumeToken();
     is_patch = true;
   } else if (CurrentToken() == Token::kEXTERNAL) {
     ConsumeToken();
     is_external = true;
   }
   if (CurrentToken() == Token::kVOID) {
     ConsumeToken();
     result_type = Type::VoidType();
   } else {
@@ skipping 105 matching lines @@
   const bool is_static = true;
   bool is_external = false;
   bool is_patch = false;
   AbstractType& result_type = AbstractType::Handle(Z);
   if (is_patch_source() && IsPatchAnnotation(metadata_pos)) {
     is_patch = true;
     metadata_pos = TokenPosition::kNoSource;
   } else if (is_patch_source() &&
       (CurrentToken() == Token::kIDENT) &&
       CurrentLiteral()->Equals("patch")) {
-    ReportWarning("deprecated use of patch 'keyword'");
+    if (FLAG_warn_patch) {
+      ReportWarning("deprecated use of patch 'keyword'");
+    }
     ConsumeToken();
     is_patch = true;
   } else if (CurrentToken() == Token::kEXTERNAL) {
     ConsumeToken();
     is_external = true;
   }
   bool is_getter = (CurrentToken() == Token::kGET);
   if (CurrentToken() == Token::kGET ||
       CurrentToken() == Token::kSET) {
     ConsumeToken();
@@ skipping 8987 matching lines @@
     const ArgumentListNode& function_args,
     const LocalVariable* temp_for_last_arg,
     bool is_super_invocation) {
   UNREACHABLE();
   return NULL;
 }
 
 }  // namespace dart
 
 #endif  // DART_PRECOMPILED_RUNTIME