Debugger: use debug break slots instead of ICs (except for calls).

src/x64/full-codegen-x64.cc

Index: src/x64/full-codegen-x64.cc
diff --git a/src/x64/full-codegen-x64.cc b/src/x64/full-codegen-x64.cc
index 7a89bd07f2beed0db6faf49c7539bc08e8870394..00a0d8f154080f0e960efce6449bf6ba7f632c27 100644
--- a/src/x64/full-codegen-x64.cc
+++ b/src/x64/full-codegen-x64.cc
@@ -472,7 +472,7 @@ void FullCodeGenerator::EmitReturnSequence() {
     Label check_exit_codesize;
     masm_->bind(&check_exit_codesize);
 #endif
-    CodeGenerator::RecordPositions(masm_, function()->end_position() - 1);
+    SetReturnPosition(function());
     __ RecordJSReturn();
     // Do not use the leave instruction here because it is too short to
     // patch with the code required by the debugger.
@@ -1046,7 +1046,7 @@ void FullCodeGenerator::VisitSwitchStatement(SwitchStatement* stmt) {
     }
 
     // Record position before stub call for type feedback.
-    SetSourcePosition(clause->position());
+    SetExpressionPosition(clause);
     Handle<Code> ic = CodeFactory::CompareIC(isolate(), Token::EQ_STRICT,
                                              strength(language_mode())).code();
     CallIC(ic, clause->CompareId());
@@ -1093,8 +1093,9 @@ void FullCodeGenerator::VisitSwitchStatement(SwitchStatement* stmt) {
 
 void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   Comment cmnt(masm_, "[ ForInStatement");
+  SetStatementPosition(stmt, SKIP_BREAK);
+
   FeedbackVectorSlot slot = stmt->ForInFeedbackSlot();
-  SetStatementPosition(stmt);
 
   Label loop, exit;
   ForIn loop_statement(this, stmt);
@@ -1102,7 +1103,7 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
 
   // Get the object to enumerate over. If the object is null or undefined, skip
   // over the loop.  See ECMA-262 version 5, section 12.6.4.
-  SetExpressionPosition(stmt->enumerable());
+  SetExpressionAsStatementPosition(stmt->enumerable());
   VisitForAccumulatorValue(stmt->enumerable());
   __ CompareRoot(rax, Heap::kUndefinedValueRootIndex);
   __ j(equal, &exit);
@@ -1206,7 +1207,7 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   // Generate code for doing the condition check.
   PrepareForBailoutForId(stmt->BodyId(), NO_REGISTERS);
   __ bind(&loop);
-  SetExpressionPosition(stmt->each());
+  SetExpressionAsStatementPosition(stmt->each());
 
   __ movp(rax, Operand(rsp, 0 * kPointerSize));  // Get the current index.
   __ cmpp(rax, Operand(rsp, 1 * kPointerSize));  // Compare to the array length.
@@ -1455,7 +1456,7 @@ void FullCodeGenerator::EmitDynamicLookupFastCase(VariableProxy* proxy,
 
 void FullCodeGenerator::EmitVariableLoad(VariableProxy* proxy) {
   // Record position before possible IC call.
-  SetSourcePosition(proxy->position());
+  SetExpressionPosition(proxy);
   PrepareForBailoutForId(proxy->BeforeId(), NO_REGISTERS);
   Variable* var = proxy->var();
 
@@ -1949,6 +1950,7 @@ void FullCodeGenerator::VisitAssignment(Assignment* expr) {
   DCHECK(expr->target()->IsValidReferenceExpression());
 
   Comment cmnt(masm_, "[ Assignment");
+  SetExpressionPosition(expr, INSERT_BREAK);
 
   Property* property = expr->target()->AsProperty();
   LhsKind assign_type = Property::GetAssignType(property);
@@ -2037,7 +2039,6 @@ void FullCodeGenerator::VisitAssignment(Assignment* expr) {
     __ Push(rax);  // Left operand goes on the stack.
     VisitForAccumulatorValue(expr->value());
 
-    SetSourcePosition(expr->position() + 1);
     AccumulatorValueContext context(this);
     if (ShouldInlineSmiCase(op)) {
       EmitInlineSmiBinaryOp(expr->binary_operation(),
@@ -2053,8 +2054,7 @@ void FullCodeGenerator::VisitAssignment(Assignment* expr) {
     VisitForAccumulatorValue(expr->value());
   }
 
-  // Record source position before possible IC call.
-  SetSourcePosition(expr->position());
+  SetExpressionPosition(expr);
 
   // Store the value.
   switch (assign_type) {
@@ -2084,6 +2084,8 @@ void FullCodeGenerator::VisitAssignment(Assignment* expr) {
 
 void FullCodeGenerator::VisitYield(Yield* expr) {
   Comment cmnt(masm_, "[ Yield");
+  SetExpressionPosition(expr);
+
   // Evaluate yielded value first; the initial iterator definition depends on
   // this.  It stays on the stack while we update the iterator.
   VisitForStackValue(expr->expression());
@@ -2370,7 +2372,7 @@ void FullCodeGenerator::EmitCreateIteratorResult(bool done) {
 
 
 void FullCodeGenerator::EmitNamedPropertyLoad(Property* prop) {
-  SetSourcePosition(prop->position());
+  SetExpressionPosition(prop);
   Literal* key = prop->key()->AsLiteral();
   DCHECK(!prop->IsSuperAccess());
 
@@ -2383,7 +2385,7 @@ void FullCodeGenerator::EmitNamedPropertyLoad(Property* prop) {
 
 void FullCodeGenerator::EmitNamedSuperPropertyLoad(Property* prop) {
   // Stack: receiver, home_object
-  SetSourcePosition(prop->position());
+  SetExpressionPosition(prop);
   Literal* key = prop->key()->AsLiteral();
   DCHECK(!key->value()->IsSmi());
   DCHECK(prop->IsSuperAccess());
@@ -2395,7 +2397,7 @@ void FullCodeGenerator::EmitNamedSuperPropertyLoad(Property* prop) {
 
 
 void FullCodeGenerator::EmitKeyedPropertyLoad(Property* prop) {
-  SetSourcePosition(prop->position());
+  SetExpressionPosition(prop);
   Handle<Code> ic = CodeFactory::KeyedLoadIC(isolate(), language_mode()).code();
   __ Move(LoadDescriptor::SlotRegister(),
           SmiFromSlot(prop->PropertyFeedbackSlot()));
@@ -2405,9 +2407,8 @@ void FullCodeGenerator::EmitKeyedPropertyLoad(Property* prop) {
 
 void FullCodeGenerator::EmitKeyedSuperPropertyLoad(Property* prop) {
   // Stack: receiver, home_object, key.
+  SetExpressionPosition(prop);
   __ Push(Smi::FromInt(language_mode()));
-  SetSourcePosition(prop->position());
-
   __ CallRuntime(Runtime::kLoadKeyedFromSuper, 4);
 }
 
@@ -2738,8 +2739,6 @@ void FullCodeGenerator::EmitNamedPropertyAssignment(Assignment* expr) {
   DCHECK(prop != NULL);
   DCHECK(prop->key()->IsLiteral());
 
-  // Record source code position before IC call.
-  SetSourcePosition(expr->position());
   __ Move(StoreDescriptor::NameRegister(), prop->key()->AsLiteral()->value());
   __ Pop(StoreDescriptor::ReceiverRegister());
   if (FLAG_vector_stores) {
@@ -2786,12 +2785,9 @@ void FullCodeGenerator::EmitKeyedSuperPropertyStore(Property* prop) {
 
 void FullCodeGenerator::EmitKeyedPropertyAssignment(Assignment* expr) {
   // Assignment to a property, using a keyed store IC.
-
   __ Pop(StoreDescriptor::NameRegister());  // Key.
   __ Pop(StoreDescriptor::ReceiverRegister());
   DCHECK(StoreDescriptor::ValueRegister().is(rax));
-  // Record source code position before IC call.
-  SetSourcePosition(expr->position());
   Handle<Code> ic =
       CodeFactory::KeyedStoreIC(isolate(), language_mode()).code();
   if (FLAG_vector_stores) {
@@ -2808,6 +2804,8 @@ void FullCodeGenerator::EmitKeyedPropertyAssignment(Assignment* expr) {
 
 void FullCodeGenerator::VisitProperty(Property* expr) {
   Comment cmnt(masm_, "[ Property");
+  SetExpressionPosition(expr);
+
   Expression* key = expr->key();
 
   if (key->IsPropertyName()) {
@@ -2885,8 +2883,8 @@ void FullCodeGenerator::EmitSuperCallWithLoadIC(Call* expr) {
   DCHECK(callee->IsProperty());
   Property* prop = callee->AsProperty();
   DCHECK(prop->IsSuperAccess());
+  SetExpressionPosition(prop);
 
-  SetSourcePosition(prop->position());
   Literal* key = prop->key()->AsLiteral();
   DCHECK(!key->value()->IsSmi());
   // Load the function from the receiver.
@@ -2947,7 +2945,7 @@ void FullCodeGenerator::EmitKeyedSuperCallWithLoadIC(Call* expr) {
   Property* prop = callee->AsProperty();
   DCHECK(prop->IsSuperAccess());
 
-  SetSourcePosition(prop->position());
+  SetExpressionPosition(prop);
   // Load the function from the receiver.
   SuperPropertyReference* super_ref = prop->obj()->AsSuperPropertyReference();
   VisitForStackValue(super_ref->home_object());
@@ -2981,14 +2979,11 @@ void FullCodeGenerator::EmitCall(Call* expr, CallICState::CallType call_type) {
   // Load the arguments.
   ZoneList<Expression*>* args = expr->arguments();
   int arg_count = args->length();
-  { PreservePositionScope scope(masm()->positions_recorder());
-    for (int i = 0; i < arg_count; i++) {
-      VisitForStackValue(args->at(i));
-    }
+  for (int i = 0; i < arg_count; i++) {
+    VisitForStackValue(args->at(i));
   }
 
-  // Record source position of the IC call.
-  SetSourcePosition(expr->position());
+  SetExpressionPosition(expr);
   Handle<Code> ic = CodeFactory::CallIC(isolate(), arg_count, call_type).code();
   __ Move(rdx, SmiFromSlot(expr->CallFeedbackICSlot()));
   __ movp(rdi, Operand(rsp, (arg_count + 1) * kPointerSize));
@@ -3047,13 +3042,10 @@ void FullCodeGenerator::PushCalleeAndWithBaseObject(Call* expr) {
   VariableProxy* callee = expr->expression()->AsVariableProxy();
   if (callee->var()->IsLookupSlot()) {
     Label slow, done;
-    SetSourcePosition(callee->position());
-    {
-      PreservePositionScope scope(masm()->positions_recorder());
-      // Generate code for loading from variables potentially shadowed by
-      // eval-introduced variables.
-      EmitDynamicLookupFastCase(callee, NOT_INSIDE_TYPEOF, &slow, &done);
-    }
+    SetExpressionPosition(callee);
+    // Generate code for loading from variables potentially shadowed by
+    // eval-introduced variables.
+    EmitDynamicLookupFastCase(callee, NOT_INSIDE_TYPEOF, &slow, &done);
     __ bind(&slow);
     // Call the runtime to find the function to call (returned in rax) and
     // the object holding it (returned in rdx).
@@ -3103,7 +3095,6 @@ void FullCodeGenerator::VisitCall(Call* expr) {
     // function using the given arguments.
     ZoneList<Expression*>* args = expr->arguments();
     int arg_count = args->length();
-    { PreservePositionScope pos_scope(masm()->positions_recorder());
       PushCalleeAndWithBaseObject(expr);
 
       // Push the arguments.
@@ -3120,9 +3111,8 @@ void FullCodeGenerator::VisitCall(Call* expr) {
       __ movp(Operand(rsp, (arg_count + 1) * kPointerSize), rax);
 
       PrepareForBailoutForId(expr->EvalId(), NO_REGISTERS);
-    }
     // Record source position for debugger.
-    SetSourcePosition(expr->position());
+      SetExpressionPosition(expr);
     CallFunctionStub stub(isolate(), arg_count, NO_CALL_FUNCTION_FLAGS);
     __ movp(rdi, Operand(rsp, (arg_count + 1) * kPointerSize));
     __ CallStub(&stub);
@@ -3147,10 +3137,7 @@ void FullCodeGenerator::VisitCall(Call* expr) {
         EmitKeyedSuperCallWithLoadIC(expr);
       }
     } else {
-      {
-        PreservePositionScope scope(masm()->positions_recorder());
         VisitForStackValue(property->obj());
-      }
       if (is_named_call) {
         EmitCallWithLoadIC(expr);
       } else {
@@ -3162,9 +3149,7 @@ void FullCodeGenerator::VisitCall(Call* expr) {
   } else {
     DCHECK(call_type == Call::OTHER_CALL);
     // Call to an arbitrary expression not handled specially above.
-    { PreservePositionScope scope(masm()->positions_recorder());
       VisitForStackValue(callee);
-    }
     __ PushRoot(Heap::kUndefinedValueRootIndex);
     // Emit function call.
     EmitCall(expr);
@@ -3198,7 +3183,7 @@ void FullCodeGenerator::VisitCallNew(CallNew* expr) {
 
   // Call the construct call builtin that handles allocation and
   // constructor invocation.
-  SetSourcePosition(expr->position());
+  SetExpressionPosition(expr);
 
   // Load function and argument count into rdi and rax.
   __ Set(rax, arg_count);
@@ -3241,7 +3226,7 @@ void FullCodeGenerator::EmitSuperConstructorCall(Call* expr) {
 
   // Call the construct call builtin that handles allocation and
   // constructor invocation.
-  SetSourcePosition(expr->position());
+  SetExpressionPosition(expr);
 
   // Load function and argument count into edi and eax.
   __ Set(rax, arg_count);
@@ -4690,8 +4675,7 @@ void FullCodeGenerator::EmitCallJSRuntimeFunction(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   int arg_count = args->length();
 
-  // Record source position of the IC call.
-  SetSourcePosition(expr->position());
+  SetExpressionPosition(expr);
   CallFunctionStub stub(isolate(), arg_count, NO_CALL_FUNCTION_FLAGS);
   __ movp(rdi, Operand(rsp, (arg_count + 1) * kPointerSize));
   __ CallStub(&stub);
@@ -4872,7 +4856,6 @@ void FullCodeGenerator::VisitCountOperation(CountOperation* expr) {
   DCHECK(expr->expression()->IsValidReferenceExpression());
 
   Comment cmnt(masm_, "[ CountOperation");
-  SetSourcePosition(expr->position());
 
   Property* prop = expr->expression()->AsProperty();
   LhsKind assign_type = Property::GetAssignType(prop);
@@ -5019,8 +5002,7 @@ void FullCodeGenerator::VisitCountOperation(CountOperation* expr) {
     }
   }
 
-  // Record position before stub call.
-  SetSourcePosition(expr->position());
+  SetExpressionPosition(expr);
 
   // Call stub for +1/-1.
   __ bind(&stub_call);
@@ -5240,7 +5222,7 @@ void FullCodeGenerator::EmitLiteralCompareTypeof(Expression* expr,
 
 void FullCodeGenerator::VisitCompareOperation(CompareOperation* expr) {
   Comment cmnt(masm_, "[ CompareOperation");
-  SetSourcePosition(expr->position());
+  SetExpressionPosition(expr);
 
   // First we try a fast inlined version of the compare when one of
   // the operands is a literal.
@@ -5294,8 +5276,6 @@ void FullCodeGenerator::VisitCompareOperation(CompareOperation* expr) {
         __ bind(&slow_case);
       }
 
-      // Record position and call the compare IC.
-      SetSourcePosition(expr->position());
       Handle<Code> ic = CodeFactory::CompareIC(
                             isolate(), op, strength(language_mode())).code();
       CallIC(ic, expr->CompareOperationFeedbackId());