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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef frontend_PropOpEmitter_h
#define frontend_PropOpEmitter_h
#include "mozilla/Attributes.h"
#include <stdint.h>
#include "js/TypeDecls.h"
class JSAtom;
namespace js {
namespace frontend {
struct BytecodeEmitter;
// Class for emitting bytecode for property operation.
//
// Usage: (check for the return value is omitted for simplicity)
//
// `obj.prop;`
// PropOpEmitter poe(this,
// PropOpEmitter::Kind::Get,
// PropOpEmitter::ObjKind::Other);
// poe.prepareForObj();
// emit(obj);
// poe.emitGet(atom_of_prop);
//
// `super.prop;`
// PropOpEmitter poe(this,
// PropOpEmitter::Kind::Get,
// PropOpEmitter::ObjKind::Super);
// poe.prepareForObj();
// emit(obj);
// poe.emitGet(atom_of_prop);
//
// `obj.prop();`
// PropOpEmitter poe(this,
// PropOpEmitter::Kind::Call,
// PropOpEmitter::ObjKind::Other);
// poe.prepareForObj();
// emit(obj);
// poe.emitGet(atom_of_prop);
// emit_call_here();
//
// `new obj.prop();`
// PropOpEmitter poe(this,
// PropOpEmitter::Kind::Call,
// PropOpEmitter::ObjKind::Other);
// poe.prepareForObj();
// emit(obj);
// poe.emitGet(atom_of_prop);
// emit_call_here();
//
// `delete obj.prop;`
// PropOpEmitter poe(this,
// PropOpEmitter::Kind::Delete,
// PropOpEmitter::ObjKind::Other);
// poe.prepareForObj();
// emit(obj);
// poe.emitDelete(atom_of_prop);
//
// `delete super.prop;`
// PropOpEmitter poe(this,
// PropOpEmitter::Kind::Delete,
// PropOpEmitter::ObjKind::Other);
// poe.emitDelete(atom_of_prop);
//
// `obj.prop++;`
// PropOpEmitter poe(this,
// PropOpEmitter::Kind::PostIncrement,
// PropOpEmitter::ObjKind::Other);
// poe.prepareForObj();
// emit(obj);
// poe.emitIncDec(atom_of_prop);
//
// `obj.prop = value;`
// PropOpEmitter poe(this,
// PropOpEmitter::Kind::SimpleAssignment,
// PropOpEmitter::ObjKind::Other);
// poe.prepareForObj();
// emit(obj);
// poe.prepareForRhs();
// emit(value);
// poe.emitAssignment(atom_of_prop);
//
// `obj.prop += value;`
// PropOpEmitter poe(this,
// PropOpEmitter::Kind::CompoundAssignment,
// PropOpEmitter::ObjKind::Other);
// poe.prepareForObj();
// emit(obj);
// poe.emitGet(atom_of_prop);
// poe.prepareForRhs();
// emit(value);
// emit_add_op_here();
// poe.emitAssignment(nullptr); // nullptr for CompoundAssignment
//
class MOZ_STACK_CLASS PropOpEmitter
{
public:
enum class Kind {
Get,
Call,
Set,
Delete,
PostIncrement,
PreIncrement,
PostDecrement,
PreDecrement,
SimpleAssignment,
PropInit,
CompoundAssignment
};
enum class ObjKind {
Super,
Other
};
private:
BytecodeEmitter* bce_;
Kind kind_;
ObjKind objKind_;
// The index for the property name's atom.
uint32_t propAtomIndex_ = 0;
// Whether the property name is `length` or not.
bool isLength_ = false;
#ifdef DEBUG
// The state of this emitter.
//
// skipObjAndRhs
// +----------------------------+
// | |
// +-------+ | prepareForObj +-----+ |
// | Start |-+-------------->| Obj |-+ |
// +-------+ +-----+ | |
// | |
// +---------------------------------+ |
// | |
// | |
// | [Get] |
// | [Call] |
// | emitGet +-----+ |
// +---------->| Get | |
// | +-----+ |
// | |
// | [Delete] |
// | emitDelete +--------+ |
// +------------->| Delete | |
// | +--------+ |
// | |
// | [PostIncrement] |
// | [PreIncrement] |
// | [PostDecrement] |
// | [PreDecrement] |
// | emitIncDec +--------+ |
// +------------->| IncDec | |
// | +--------+ |
// | |
// | [SimpleAssignment] |
// | [PropInit] |
// | prepareForRhs | +-----+
// +--------------------->+-------------->+->| Rhs |-+
// | ^ +-----+ |
// | | |
// | | +---------+
// | [CompoundAssignment] | |
// | emitGet +-----+ | | emitAssignment +------------+
// +---------->| Get |----+ + -------------->| Assignment |
// +-----+ +------------+
enum class State {
// The initial state.
Start,
// After calling prepareForObj.
Obj,
// After calling emitGet.
Get,
// After calling emitDelete.
Delete,
// After calling emitIncDec.
IncDec,
// After calling prepareForRhs or skipObjAndRhs.
Rhs,
// After calling emitAssignment.
Assignment,
};
State state_ = State::Start;
#endif
public:
PropOpEmitter(BytecodeEmitter* bce, Kind kind, ObjKind objKind);
private:
MOZ_MUST_USE bool isCall() const {
return kind_ == Kind::Call;
}
MOZ_MUST_USE bool isSuper() const {
return objKind_ == ObjKind::Super;
}
MOZ_MUST_USE bool isSimpleAssignment() const {
return kind_ == Kind::SimpleAssignment;
}
MOZ_MUST_USE bool isPropInit() const {
return kind_ == Kind::PropInit;
}
MOZ_MUST_USE bool isDelete() const {
return kind_ == Kind::Delete;
}
MOZ_MUST_USE bool isCompoundAssignment() const {
return kind_ == Kind::CompoundAssignment;
}
MOZ_MUST_USE bool isIncDec() const {
return isPostIncDec() || isPreIncDec();
}
MOZ_MUST_USE bool isPostIncDec() const {
return kind_ == Kind::PostIncrement ||
kind_ == Kind::PostDecrement;
}
MOZ_MUST_USE bool isPreIncDec() const {
return kind_ == Kind::PreIncrement ||
kind_ == Kind::PreDecrement;
}
MOZ_MUST_USE bool isInc() const {
return kind_ == Kind::PostIncrement ||
kind_ == Kind::PreIncrement;
}
MOZ_MUST_USE bool
prepareAtomIndex(JSAtom* prop);
public:
MOZ_MUST_USE bool prepareForObj();
MOZ_MUST_USE bool emitGet(JSAtom* prop);
MOZ_MUST_USE bool prepareForRhs();
MOZ_MUST_USE bool skipObjAndRhs();
MOZ_MUST_USE bool emitDelete(JSAtom* prop);
// `prop` can be nullptr for CompoundAssignment.
MOZ_MUST_USE bool emitAssignment(JSAtom* prop);
MOZ_MUST_USE bool emitIncDec(JSAtom* prop);
};
} /* namespace frontend */
} /* namespace js */
#endif /* frontend_PropOpEmitter_h */
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