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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
* 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_ElemOpEmitter_h
#define frontend_ElemOpEmitter_h
#include "mozilla/Attributes.h"
namespace js {
namespace frontend {
struct BytecodeEmitter;
enum class ValueUsage;
// Class for emitting bytecode for element operation.
//
// Usage: (check for the return value is omitted for simplicity)
//
// `obj[key];`
// ElemOpEmitter eoe(this,
// ElemOpEmitter::Kind::Get,
// ElemOpEmitter::ObjKind::Other);
// eoe.prepareForObj();
// emit(obj);
// eoe.prepareForKey();
// emit(key);
// eoe.emitGet();
//
// `super[key];`
// ElemOpEmitter eoe(this,
// ElemOpEmitter::Kind::Get,
// ElemOpEmitter::ObjKind::Super);
// eoe.prepareForObj();
// emit(this_for_super);
// eoe.prepareForKey();
// emit(key);
// eoe.emitGet();
//
// `obj[key]();`
// ElemOpEmitter eoe(this,
// ElemOpEmitter::Kind::Call,
// ElemOpEmitter::ObjKind::Other);
// eoe.prepareForObj();
// emit(obj);
// eoe.prepareForKey();
// emit(key);
// eoe.emitGet();
// emit_call_here();
//
// `new obj[key]();`
// ElemOpEmitter eoe(this,
// ElemOpEmitter::Kind::Call,
// ElemOpEmitter::ObjKind::Other);
// eoe.prepareForObj();
// emit(obj);
// eoe.prepareForKey();
// emit(key);
// eoe.emitGet();
// emit_call_here();
//
// `delete obj[key];`
// ElemOpEmitter eoe(this,
// ElemOpEmitter::Kind::Delete,
// ElemOpEmitter::ObjKind::Other);
// eoe.prepareForObj();
// emit(obj);
// eoe.prepareForKey();
// emit(key);
// eoe.emitDelete();
//
// `delete super[key];`
// ElemOpEmitter eoe(this,
// ElemOpEmitter::Kind::Delete,
// ElemOpEmitter::ObjKind::Super);
// eoe.prepareForObj();
// emit(this_for_super);
// eoe.prepareForKey();
// emit(key);
// eoe.emitDelete();
//
// `obj[key]++;`
// ElemOpEmitter eoe(this,
// ElemOpEmitter::Kind::PostIncrement,
// ElemOpEmitter::ObjKind::Other);
// eoe.prepareForObj();
// emit(obj);
// eoe.prepareForKey();
// emit(key);
// eoe.emitIncDec();
//
// `obj[key] = value;`
// ElemOpEmitter eoe(this,
// ElemOpEmitter::Kind::SimpleAssignment,
// ElemOpEmitter::ObjKind::Other);
// eoe.prepareForObj();
// emit(obj);
// eoe.prepareForKey();
// emit(key);
// eoe.prepareForRhs();
// emit(value);
// eoe.emitAssignment();
//
// `obj[key] += value;`
// ElemOpEmitter eoe(this,
// ElemOpEmitter::Kind::CompoundAssignment,
// ElemOpEmitter::ObjKind::Other);
// eoe.prepareForObj();
// emit(obj);
// eoe.prepareForKey();
// emit(key);
// eoe.emitGet();
// eoe.prepareForRhs();
// emit(value);
// emit_add_op_here();
// eoe.emitAssignment();
//
class MOZ_STACK_CLASS ElemOpEmitter {
public:
enum class Kind {
Get,
Call,
Delete,
PostIncrement,
PreIncrement,
PostDecrement,
PreDecrement,
SimpleAssignment,
PropInit,
CompoundAssignment
};
enum class ObjKind { Super, Other };
private:
BytecodeEmitter* bce_;
Kind kind_;
ObjKind objKind_;
#ifdef DEBUG
// The state of this emitter.
//
// skipObjAndKeyAndRhs
// +------------------------------------------------+
// | |
// +-------+ | prepareForObj +-----+ prepareForKey +-----+ |
// | Start |-+-------------->| Obj |-------------->| Key |-+ |
// +-------+ +-----+ +-----+ | |
// | |
// +-------------------------------------------------------+ |
// | |
// | [Get] |
// | [Call] |
// | emitGet +-----+ |
// +---------->| Get | |
// | +-----+ |
// | |
// | [Delete] |
// | emitDelete +--------+ |
// +------------->| Delete | |
// | +--------+ |
// | |
// | [PostIncrement] |
// | [PreIncrement] |
// | [PostDecrement] |
// | [PreDecrement] |
// | emitIncDec +--------+ |
// +------------->| IncDec | |
// | +--------+ |
// | +-------------------+
// | [SimpleAssignment] |
// | [PropInit] |
// | prepareForRhs v +-----+
// +--------------------->+-------------->+->| Rhs |-+
// | ^ +-----+ |
// | | |
// | | +-------------+
// | [CompoundAssignment] | |
// | emitGet +-----+ | | emitAssignment +------------+
// +---------->| Get |----+ +--------------->| Assignment |
// +-----+ +------------+
enum class State {
// The initial state.
Start,
// After calling prepareForObj.
Obj,
// After calling emitKey.
Key,
// After calling emitGet.
Get,
// After calling emitDelete.
Delete,
// After calling emitIncDec.
IncDec,
// After calling prepareForRhs or skipObjAndKeyAndRhs.
Rhs,
// After calling emitAssignment.
Assignment,
};
State state_ = State::Start;
#endif
public:
ElemOpEmitter(BytecodeEmitter* bce, Kind kind, ObjKind objKind);
private:
[[nodiscard]] bool isCall() const { return kind_ == Kind::Call; }
[[nodiscard]] bool isSimpleAssignment() const {
return kind_ == Kind::SimpleAssignment;
}
[[nodiscard]] bool isPropInit() const { return kind_ == Kind::PropInit; }
[[nodiscard]] bool isDelete() const { return kind_ == Kind::Delete; }
[[nodiscard]] bool isCompoundAssignment() const {
return kind_ == Kind::CompoundAssignment;
}
[[nodiscard]] bool isIncDec() const {
return isPostIncDec() || isPreIncDec();
}
[[nodiscard]] bool isPostIncDec() const {
return kind_ == Kind::PostIncrement || kind_ == Kind::PostDecrement;
}
[[nodiscard]] bool isPreIncDec() const {
return kind_ == Kind::PreIncrement || kind_ == Kind::PreDecrement;
}
[[nodiscard]] bool isInc() const {
return kind_ == Kind::PostIncrement || kind_ == Kind::PreIncrement;
}
[[nodiscard]] bool isSuper() const { return objKind_ == ObjKind::Super; }
public:
[[nodiscard]] bool prepareForObj();
[[nodiscard]] bool prepareForKey();
[[nodiscard]] bool emitGet();
[[nodiscard]] bool prepareForRhs();
[[nodiscard]] bool skipObjAndKeyAndRhs();
[[nodiscard]] bool emitDelete();
[[nodiscard]] bool emitAssignment();
[[nodiscard]] bool emitIncDec(ValueUsage valueUsage);
};
} /* namespace frontend */
} // namespace js
#endif /* frontend_ElemOpEmitter_h */
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