Reviewers: rossberg, adamk,
Message:
Andreas: PTAL.
Adam: FYI.
Description:
Represent implicit 'this' binding by 'super' in AST.
This makes the implicit initializing assignment to 'this' performed
after a super constructor call explicit in the AST. It removes the
need to handle the special case where a CallExpression behaves like a
AssignmentExpression from various AstVisitor implementations.
[email protected]
Please review this at https://codereview.chromium.org/1226123010/
Base URL: https://chromium.googlesource.com/v8/v8.git@master
Affected files (+53, -44 lines):
M src/ast.h
M src/ast.cc
M src/compiler/ast-graph-builder.cc
M src/compiler/ast-loop-assignment-analyzer.cc
M src/full-codegen.h
M src/ia32/full-codegen-ia32.cc
M src/preparser.h
Index: src/ast.cc
diff --git a/src/ast.cc b/src/ast.cc
index
93cb6c09b99358f6a118f58e83442ef01f58e832..de229cb014ea36ad65f0f8d927646659a183d30e
100644
--- a/src/ast.cc
+++ b/src/ast.cc
@@ -59,6 +59,11 @@ bool Expression::IsUndefinedLiteral(Isolate* isolate)
const {
}
+bool Expression::IsVariableProxyOrProperty() const {
+ return IsVariableProxy() || IsProperty();
+}
+
+
VariableProxy::VariableProxy(Zone* zone, Variable* var, int start_position,
int end_position)
: Expression(zone, start_position),
Index: src/ast.h
diff --git a/src/ast.h b/src/ast.h
index
b1a634edb4c7f02f4dc96658e3e9dba6c5cb9908..1cb9cedfdff4d1d2f23ea81a167aff557924b301
100644
--- a/src/ast.h
+++ b/src/ast.h
@@ -362,6 +362,9 @@ class Expression : public AstNode {
// True if we can prove that the expression is the undefined literal.
bool IsUndefinedLiteral(Isolate* isolate) const;
+ // True iff the expression represents a variable or a property.
+ bool IsVariableProxyOrProperty() const;
+
// Expression type bounds
Bounds bounds() const { return bounds_; }
void set_bounds(Bounds bounds) { bounds_ = bounds; }
Index: src/compiler/ast-graph-builder.cc
diff --git a/src/compiler/ast-graph-builder.cc
b/src/compiler/ast-graph-builder.cc
index
0c0bb02ea5bd24d1a5b83c207ff00652ca4608ce..1dd7e5fee99bb27ce3e952bfb718b677e06bbc48
100644
--- a/src/compiler/ast-graph-builder.cc
+++ b/src/compiler/ast-graph-builder.cc
@@ -2016,7 +2016,7 @@ void AstGraphBuilder::VisitArrayLiteral(ArrayLiteral*
expr) {
void AstGraphBuilder::VisitForInAssignment(Expression* expr, Node* value,
const VectorSlotPair& feedback,
BailoutId bailout_id) {
- DCHECK(expr->IsValidReferenceExpression());
+ DCHECK(expr->IsVariableProxyOrProperty());
// Left-hand side can only be a property, a global or a variable slot.
Property* property = expr->AsProperty();
@@ -2090,7 +2090,7 @@ void
AstGraphBuilder::VisitForInAssignment(Expression* expr, Node* value,
void AstGraphBuilder::VisitAssignment(Assignment* expr) {
- DCHECK(expr->target()->IsValidReferenceExpression());
+ DCHECK(expr->target()->IsVariableProxyOrProperty());
// Left-hand side can only be a property, a global or a variable slot.
Property* property = expr->target()->AsProperty();
@@ -2520,12 +2520,6 @@ void AstGraphBuilder::VisitCallSuper(Call* expr) {
const Operator* call = javascript()->CallConstruct(args->length() + 2);
Node* value = ProcessArguments(call, args->length() + 2);
PrepareFrameState(value, expr->id(), ast_context()->GetStateCombine());
-
- // TODO(mstarzinger): It sure would be nice if this were desugared.
- FrameStateBeforeAndAfter states(this, BailoutId::None());
- BuildVariableAssignment(super->this_var()->var(), value,
Token::INIT_CONST,
- VectorSlotPair(), expr->id(), states);
-
ast_context()->ProduceValue(value);
}
@@ -2627,7 +2621,7 @@ void
AstGraphBuilder::VisitUnaryOperation(UnaryOperation* expr) {
void AstGraphBuilder::VisitCountOperation(CountOperation* expr) {
- DCHECK(expr->expression()->IsValidReferenceExpression());
+ DCHECK(expr->expression()->IsVariableProxyOrProperty());
// Left-hand side can only be a property, a global or a variable slot.
Property* property = expr->expression()->AsProperty();
Index: src/compiler/ast-loop-assignment-analyzer.cc
diff --git a/src/compiler/ast-loop-assignment-analyzer.cc
b/src/compiler/ast-loop-assignment-analyzer.cc
index
e0a92a464c487e7e1b74b88321d28298c2502f33..61ed4f27cbba8e7d7b9287108a87ab9e8f3435e2
100644
--- a/src/compiler/ast-loop-assignment-analyzer.cc
+++ b/src/compiler/ast-loop-assignment-analyzer.cc
@@ -161,11 +161,6 @@ void ALAA::VisitProperty(Property* e) {
void ALAA::VisitCall(Call* e) {
Visit(e->expression());
VisitExpressions(e->arguments());
- // TODO(mstarzinger): It sure would be nice if this were desugared.
- if (e->GetCallType(isolate()) == Call::SUPER_CALL) {
- SuperCallReference* super = e->expression()->AsSuperCallReference();
- AnalyzeAssignment(super->this_var()->var());
- }
}
Index: src/full-codegen.h
diff --git a/src/full-codegen.h b/src/full-codegen.h
index
ccc10e061bcdfd8704cbae57caee662ff19ca7e2..88a88f45b2d56c5924e0219bfc7d8ca29d7f5b52
100644
--- a/src/full-codegen.h
+++ b/src/full-codegen.h
@@ -644,9 +644,6 @@ class FullCodeGenerator: public AstVisitor {
FeedbackVectorICSlot slot = FeedbackVectorICSlot::Invalid());
void EmitLoadSuperConstructor(SuperCallReference* super_call_ref);
- void EmitInitializeThisAfterSuper(
- SuperCallReference* super_call_ref,
- FeedbackVectorICSlot slot = FeedbackVectorICSlot::Invalid());
void CallIC(Handle<Code> code,
TypeFeedbackId id = TypeFeedbackId::None());
Index: src/ia32/full-codegen-ia32.cc
diff --git a/src/ia32/full-codegen-ia32.cc b/src/ia32/full-codegen-ia32.cc
index
820d28ea6886e458894ea414943532ddf4578e00..d212eccd50b2d595ac81a1926e5444b72f301f06
100644
--- a/src/ia32/full-codegen-ia32.cc
+++ b/src/ia32/full-codegen-ia32.cc
@@ -1927,7 +1927,7 @@ void
FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
void FullCodeGenerator::VisitAssignment(Assignment* expr) {
- DCHECK(expr->target()->IsValidReferenceExpression());
+ DCHECK(expr->target()->IsVariableProxyOrProperty());
Comment cmnt(masm_, "[ Assignment");
SetExpressionPosition(expr, INSERT_BREAK);
@@ -2584,7 +2584,7 @@ void FullCodeGenerator::EmitBinaryOp(BinaryOperation*
expr, Token::Value op) {
void FullCodeGenerator::EmitAssignment(Expression* expr,
FeedbackVectorICSlot slot) {
- DCHECK(expr->IsValidReferenceExpression());
+ DCHECK(expr->IsVariableProxyOrProperty());
Property* prop = expr->AsProperty();
LhsKind assign_type = Property::GetAssignType(prop);
@@ -2726,6 +2726,19 @@ void
FullCodeGenerator::EmitVariableAssignment(Variable* var, Token::Value op,
__ bind(&const_error);
__ CallRuntime(Runtime::kThrowConstAssignError, 0);
+ } else if (var->is_this() && op == Token::INIT_CONST) {
+ // Initializing assignment to const {this} needs a write barrier.
+ DCHECK(var->IsStackAllocated() || var->IsContextSlot());
+ Label uninitialized_this;
+ MemOperand location = VarOperand(var, ecx);
+ __ mov(edx, location);
+ __ cmp(edx, isolate()->factory()->the_hole_value());
+ __ j(equal, &uninitialized_this);
+ __ push(Immediate(var->name()));
+ __ CallRuntime(Runtime::kThrowReferenceError, 1);
+ __ bind(&uninitialized_this);
+ EmitStoreToStackLocalOrContextSlot(var, location);
+
} else if (!var->is_const_mode() || op == Token::INIT_CONST) {
if (var->IsLookupSlot()) {
// Assignment to var.
@@ -3068,22 +3081,6 @@ void
FullCodeGenerator::EmitResolvePossiblyDirectEval(int arg_count) {
}
-void FullCodeGenerator::EmitInitializeThisAfterSuper(
- SuperCallReference* super_call_ref, FeedbackVectorICSlot slot) {
- Variable* this_var = super_call_ref->this_var()->var();
- GetVar(ecx, this_var);
- __ cmp(ecx, isolate()->factory()->the_hole_value());
-
- Label uninitialized_this;
- __ j(equal, &uninitialized_this);
- __ push(Immediate(this_var->name()));
- __ CallRuntime(Runtime::kThrowReferenceError, 1);
- __ bind(&uninitialized_this);
-
- EmitVariableAssignment(this_var, Token::INIT_CONST, slot);
-}
-
-
// See http://www.ecma-international.org/ecma-262/6.0/#sec-function-calls.
void FullCodeGenerator::PushCalleeAndWithBaseObject(Call* expr) {
VariableProxy* callee = expr->expression()->AsVariableProxy();
@@ -3299,7 +3296,6 @@ void
FullCodeGenerator::EmitSuperConstructorCall(Call* expr) {
RecordJSReturnSite(expr);
- EmitInitializeThisAfterSuper(super_call_ref, expr->CallFeedbackICSlot());
context()->Plug(eax);
}
@@ -4675,9 +4671,6 @@ void
FullCodeGenerator::EmitCallSuperWithSpread(CallRuntime* expr) {
// Restore context register.
__ mov(esi, Operand(ebp, StandardFrameConstants::kContextOffset));
context()->DropAndPlug(1, eax);
-
- // TODO(mvstanton): with FLAG_vector_stores this needs a slot id.
- EmitInitializeThisAfterSuper(super_call_ref);
}
@@ -4876,7 +4869,7 @@ void
FullCodeGenerator::VisitUnaryOperation(UnaryOperation* expr) {
void FullCodeGenerator::VisitCountOperation(CountOperation* expr) {
- DCHECK(expr->expression()->IsValidReferenceExpression());
+ DCHECK(expr->expression()->IsVariableProxyOrProperty());
Comment cmnt(masm_, "[ CountOperation");
Index: src/preparser.h
diff --git a/src/preparser.h b/src/preparser.h
index
921cd875a1816abaee53eed6db15e6222465bc5a..a4edc37a2aba5959106e1acac0c54a6947040a50
100644
--- a/src/preparser.h
+++ b/src/preparser.h
@@ -947,10 +947,16 @@ class PreParserExpression {
ExpressionTypeField::encode(kCallExpression));
}
+ static PreParserExpression SuperCallReference() {
+ return PreParserExpression(
+ TypeField::encode(kExpression) |
+ ExpressionTypeField::encode(kSuperCallReference));
+ }
+
static PreParserExpression NoTemplateTag() {
- return PreParserExpression(TypeField::encode(kExpression) |
- ExpressionTypeField::encode(
- kNoTemplateTagExpression));
+ return PreParserExpression(
+ TypeField::encode(kExpression) |
+ ExpressionTypeField::encode(kNoTemplateTagExpression));
}
bool IsIdentifier() const {
@@ -997,6 +1003,11 @@ class PreParserExpression {
ExpressionTypeField::decode(code_) == kCallExpression;
}
+ bool IsSuperCallReference() const {
+ return TypeField::decode(code_) == kExpression &&
+ ExpressionTypeField::decode(code_) == kSuperCallReference;
+ }
+
bool IsValidReferenceExpression() const {
return IsIdentifier() || IsProperty();
}
@@ -1045,6 +1056,7 @@ class PreParserExpression {
kThisPropertyExpression,
kPropertyExpression,
kCallExpression,
+ kSuperCallReference,
kNoTemplateTagExpression
};
@@ -1528,7 +1540,7 @@ class PreParserTraits {
static PreParserExpression SuperCallReference(Scope* scope,
PreParserFactory* factory,
int pos) {
- return PreParserExpression::Default();
+ return PreParserExpression::SuperCallReference();
}
static PreParserExpression NewTargetExpression(Scope* scope,
@@ -3184,12 +3196,22 @@ ParserBase<Traits>::ParseLeftHandSideExpression(
// they are actually direct calls to eval is determined at run
time.
this->CheckPossibleEvalCall(result, scope_);
+ bool is_super_call = result->IsSuperCallReference();
if (spread_pos.IsValid()) {
args = Traits::PrepareSpreadArguments(args);
result = Traits::SpreadCall(result, args, pos);
} else {
result = factory()->NewCall(result, args, pos);
}
+
+ // Explicit calls to the super constructor using super() perform
and
+ // implicit binding assignment to the 'this' variable.
+ if (is_super_call) {
+ ExpressionT this_expr = this->ThisExpression(scope_, factory(),
pos);
+ result = factory()->NewAssignment(Token::INIT_CONST, this_expr,
+ result, pos);
+ }
+
if (fni_ != NULL) fni_->RemoveLastFunction();
break;
}
--
--
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