Step next should respect do/while condition block.

Condition block of do/while statements is a valid break location so it should have its own position. The block is represented by a regular Expression node so we cannot store the position in it, instead the position is stored in a separate field in DoWhileStatement AST node.

BUG=514
Review URL: http://codereview.chromium.org/385136

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3312 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/codegen-arm.cc

@@ -1583,6 +1583,8 @@ void CodeGenerator::VisitDoWhileStatement(DoWhileStatement* node) {
         node->continue_target()->Bind();
       }
       if (has_valid_frame()) {
+        Comment cmnt(masm_, "[ DoWhileCondition");
+        CodeForDoWhileConditionPosition(node);
         LoadConditionAndSpill(node->cond(), &body, node->break_target(), true);
         if (has_valid_frame()) {
           // A invalid frame here indicates that control did not

src/arm/codegen-arm.h

@@ -378,6 +378,7 @@ class CodeGenerator: public AstVisitor {
   void CodeForFunctionPosition(FunctionLiteral* fun);
   void CodeForReturnPosition(FunctionLiteral* fun);
   void CodeForStatementPosition(Statement* node);
+  void CodeForDoWhileConditionPosition(DoWhileStatement* stmt);
   void CodeForSourcePosition(int pos);
 
 #ifdef DEBUG

src/ast.h

@@ -322,7 +322,7 @@ class IterationStatement: public BreakableStatement {
 class DoWhileStatement: public IterationStatement {
  public:
   explicit DoWhileStatement(ZoneStringList* labels)
-      : IterationStatement(labels), cond_(NULL) {
+      : IterationStatement(labels), cond_(NULL), condition_position_(-1) {
   }
 
   void Initialize(Expression* cond, Statement* body) {
@@ -334,8 +334,14 @@ class DoWhileStatement: public IterationStatement {
 
   Expression* cond() const { return cond_; }
 
+  // Position where condition expression starts. We need it to make
+  // the loop's condition a breakable location.
+  int condition_position() { return condition_position_; }
+  void set_condition_position(int pos) { condition_position_ = pos; }
+
  private:
   Expression* cond_;
+  int condition_position_;
 };
 
 

src/codegen.cc

@@ -431,6 +431,9 @@ void CodeGenerator::CodeForStatementPosition(Statement* stmt) {
   if (FLAG_debug_info) RecordPositions(masm(), stmt->statement_pos());
 }
 
+void CodeGenerator::CodeForDoWhileConditionPosition(DoWhileStatement* stmt) {
+  if (FLAG_debug_info) RecordPositions(masm(), stmt->condition_position());
+}
 
 void CodeGenerator::CodeForSourcePosition(int pos) {
   if (FLAG_debug_info && pos != RelocInfo::kNoPosition) {

src/codegen.h

@@ -69,6 +69,7 @@
 //   CodeForFunctionPosition
 //   CodeForReturnPosition
 //   CodeForStatementPosition
+//   CodeForDoWhileConditionPosition
 //   CodeForSourcePosition
 
 

src/ia32/codegen-ia32.cc

@@ -2449,6 +2449,7 @@ void CodeGenerator::VisitReturnStatement(ReturnStatement* node) {
   CodeForStatementPosition(node);
   Load(node->expression());
   Result return_value = frame_->Pop();
+  masm()->WriteRecordedPositions();
   if (function_return_is_shadowed_) {
     function_return_.Jump(&return_value);
   } else {
@@ -2712,6 +2713,8 @@ void CodeGenerator::VisitDoWhileStatement(DoWhileStatement* node) {
         node->continue_target()->Bind();
       }
       if (has_valid_frame()) {
+        Comment cmnt(masm_, "[ DoWhileCondition");
+        CodeForDoWhileConditionPosition(node);
         ControlDestination dest(&body, node->break_target(), false);
         LoadCondition(node->cond(), &dest, true);
       }

src/ia32/codegen-ia32.h

@@ -556,6 +556,7 @@ class CodeGenerator: public AstVisitor {
   void CodeForFunctionPosition(FunctionLiteral* fun);
   void CodeForReturnPosition(FunctionLiteral* fun);
   void CodeForStatementPosition(Statement* stmt);
+  void CodeForDoWhileConditionPosition(DoWhileStatement* stmt);
   void CodeForSourcePosition(int pos);
 
 #ifdef DEBUG

src/parser.cc

@@ -2542,6 +2542,12 @@ DoWhileStatement* Parser::ParseDoWhileStatement(ZoneStringList* labels,
   Statement* body = ParseStatement(NULL, CHECK_OK);
   Expect(Token::WHILE, CHECK_OK);
   Expect(Token::LPAREN, CHECK_OK);
+
+  if (loop != NULL) {
+    int position = scanner().location().beg_pos;
+    loop->set_condition_position(position);
+  }
+
   Expression* cond = ParseExpression(true, CHECK_OK);
   Expect(Token::RPAREN, CHECK_OK);
 

src/x64/codegen-x64.cc

@@ -1318,6 +1318,8 @@ void CodeGenerator::VisitDoWhileStatement(DoWhileStatement* node) {
         node->continue_target()->Bind();
       }
       if (has_valid_frame()) {
+        Comment cmnt(masm_, "[ DoWhileCondition");
+        CodeForDoWhileConditionPosition(node);
         ControlDestination dest(&body, node->break_target(), false);
         LoadCondition(node->cond(), &dest, true);
       }

src/x64/codegen-x64.h

@@ -556,6 +556,7 @@ class CodeGenerator: public AstVisitor {
   void CodeForFunctionPosition(FunctionLiteral* fun);
   void CodeForReturnPosition(FunctionLiteral* fun);
   void CodeForStatementPosition(Statement* node);
+  void CodeForDoWhileConditionPosition(DoWhileStatement* stmt);
   void CodeForSourcePosition(int pos);
 
 #ifdef DEBUG

test/mjsunit/debug-stepnext-do-while.js

+// Copyright 2009 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Flags: --expose-debug-as debug
+// Get the Debug object exposed from the debug context global object.
+Debug = debug.Debug
+
+var exception = null;
+var break_break_point_hit_count = 0;
+
+function listener(event, exec_state, event_data, data) {
+  try {
+    if (event == Debug.DebugEvent.Break) {
+      if (break_break_point_hit_count == 0) {
+        assertEquals('    debugger;',
+                     event_data.sourceLineText());
+        assertEquals('runDoWhile', event_data.func().name());
+      } else if (break_break_point_hit_count == 1) {
+        assertEquals('  } while(condition());',
+                     event_data.sourceLineText());
+        assertEquals('runDoWhile', event_data.func().name());
+      }
+
+      break_break_point_hit_count++;
+      // Continue stepping until returned to bottom frame.
+      if (exec_state.frameCount() > 1) {
+        exec_state.prepareStep(Debug.StepAction.StepNext);
+      }
+
+    }
+  } catch(e) {
+    exception = e;
+  }
+};
+
+// Add the debug event listener.
+Debug.setListener(listener);
+
+function condition() {
+  return false;
+}
+
+function runDoWhile() {
+  do {
+    debugger;
+  } while(condition());
+};
+
+break_break_point_hit_count = 0;
+runDoWhile();
+assertNull(exception);
+assertEquals(4, break_break_point_hit_count);
+
+// Get rid of the debug event listener.
+Debug.setListener(null);