Add support for debug break in Dart source.

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 "lib/invocation_mirror.h"
 #include "platform/utils.h"
 #include "vm/ast_transformer.h"
 #include "vm/bootstrap.h"
@@ skipping 20 matching lines @@
 #include "vm/scopes.h"
 #include "vm/stack_frame.h"
 #include "vm/symbols.h"
 #include "vm/tags.h"
 #include "vm/timer.h"
 #include "vm/zone.h"
 
 namespace dart {
 
 DEFINE_FLAG(bool, enable_asserts, false, "Enable assert statements.");
+DEFINE_FLAG(bool, enable_debug_break, false, "Allow use of break \"message\".");
 DEFINE_FLAG(bool, enable_type_checks, false, "Enable type checks.");
 DEFINE_FLAG(bool, trace_parser, false, "Trace parser operations.");
 DEFINE_FLAG(bool, warn_mixin_typedef, true, "Warning on legacy mixin typedef.");
 DECLARE_FLAG(bool, error_on_bad_type);
 DECLARE_FLAG(bool, throw_on_javascript_int_overflow);
 DECLARE_FLAG(bool, warn_on_javascript_compatibility);
 
 static void CheckedModeHandler(bool value) {
   FLAG_enable_asserts = value;
   FLAG_enable_type_checks = value;
@@ skipping 9506 matching lines @@
       if (switch_scope != NULL) {
         // We found a switch scope. Enter a forward reference to the label.
         target = new(Z) SourceLabel(
             TokenPos(), target_name, SourceLabel::kForward);
         switch_scope->AddLabel(target);
       }
     }
     if (target == NULL) {
       ReportError(jump_pos, "label '%s' not found", target_name.ToCString());
     }
+  } else if (FLAG_enable_debug_break && (CurrentToken() == Token::kSTRING)) {
+    const char* message = strdup(CurrentLiteral()->ToCString());

[Ivan Posva, 2015/04/16 21:44:51]

Who is responsible for freeing this memory?

[Ivan Posva, 2015/04/16 21:47:05]

Got the answer for this one: Stop does not do a strdup. It is the related
Unimplemented and similar which do allocate the final string.

[regis, 2015/04/16 22:17:04]

Yes, the strdup is necessary, since the literal string gets freed before
execution. We have many other places allocating error strings with malloc.

+    ConsumeToken();
+    return new(Z) StopNode(jump_pos, message);
   } else {
     target = current_block_->scope->LookupInnermostLabel(jump_kind);
     if (target == NULL) {
       ReportError(jump_pos, "'%s' is illegal here", Token::Str(jump_kind));
     }
   }
   ASSERT(target != NULL);
   if (jump_kind == Token::kCONTINUE) {
     if (target->kind() == SourceLabel::kSwitch) {
       ReportError(jump_pos, "'continue' jump to switch statement is illegal");
@@ skipping 241 matching lines @@
     }
     ConsumeToken();
     ParseStatementSequence();
     statement = CloseBlock();
     if (label != NULL) {
       statement->AsSequenceNode()->set_label(label);
     }
     ExpectToken(Token::kRBRACE);
   } else if (token == Token::kBREAK) {
     statement = ParseJump(label_name);
-    AddNodeForFinallyInlining(statement);
+    if ((statement != NULL) && !statement->IsStopNode()) {
+      AddNodeForFinallyInlining(statement);
+    }
     ExpectSemicolon();
   } else if (token == Token::kCONTINUE) {
     statement = ParseJump(label_name);
     AddNodeForFinallyInlining(statement);
     ExpectSemicolon();
   } else if (token == Token::kSEMICOLON) {
     // Empty statement, nothing to do.
     ConsumeToken();
   } else if (token == Token::kRETHROW) {
     // Rethrow of current exception.
@@ skipping 3656 matching lines @@
 void Parser::SkipQualIdent() {
   ASSERT(IsIdentifier());
   ConsumeToken();
   if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();  // Consume the kPERIOD token.
     ExpectIdentifier("identifier expected after '.'");
   }
 }
 
 }  // namespace dart