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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_CallOrNewEmitter_h
#define frontend_CallOrNewEmitter_h
#include "mozilla/Attributes.h"
#include "mozilla/Maybe.h"
#include <stdint.h>
#include "frontend/ElemOpEmitter.h"
#include "frontend/IfEmitter.h"
#include "frontend/PropOpEmitter.h"
#include "frontend/ValueUsage.h"
#include "js/TypeDecls.h"
#include "vm/BytecodeUtil.h"
#include "vm/Opcodes.h"
namespace js {
namespace frontend {
struct BytecodeEmitter;
// Class for emitting bytecode for call or new expression.
//
// Usage: (check for the return value is omitted for simplicity)
//
// `print(arg);`
// CallOrNewEmitter cone(this, JSOp::Call,
// CallOrNewEmitter::ArgumentsKind::Other,
// ValueUsage::WantValue);
// cone.emitNameCallee(print);
// cone.emitThis();
// cone.prepareForNonSpreadArguments();
// emit(arg);
// cone.emitEnd(1, Some(offset_of_callee));
//
// `callee.prop(arg1, arg2);`
// CallOrNewEmitter cone(this, JSOp::Call,
// CallOrNewEmitter::ArgumentsKind::Other,
// ValueUsage::WantValue);
// PropOpEmitter& poe = cone.prepareForPropCallee(false);
// ... emit `callee.prop` with `poe` here...
// cone.emitThis();
// cone.prepareForNonSpreadArguments();
// emit(arg1);
// emit(arg2);
// cone.emitEnd(2, Some(offset_of_callee));
//
// `callee[key](arg);`
// CallOrNewEmitter cone(this, JSOp::Call,
// CallOrNewEmitter::ArgumentsKind::Other,
// ValueUsage::WantValue);
// ElemOpEmitter& eoe = cone.prepareForElemCallee(false);
// ... emit `callee[key]` with `eoe` here...
// cone.emitThis();
// cone.prepareForNonSpreadArguments();
// emit(arg);
// cone.emitEnd(1, Some(offset_of_callee));
//
// `(function() { ... })(arg);`
// CallOrNewEmitter cone(this, JSOp::Call,
// CallOrNewEmitter::ArgumentsKind::Other,
// ValueUsage::WantValue);
// cone.prepareForFunctionCallee();
// emit(function);
// cone.emitThis();
// cone.prepareForNonSpreadArguments();
// emit(arg);
// cone.emitEnd(1, Some(offset_of_callee));
//
// `super(arg);`
// CallOrNewEmitter cone(this, JSOp::Call,
// CallOrNewEmitter::ArgumentsKind::Other,
// ValueUsage::WantValue);
// cone.emitSuperCallee();
// cone.emitThis();
// cone.prepareForNonSpreadArguments();
// emit(arg);
// cone.emitEnd(1, Some(offset_of_callee));
//
// `(some_other_expression)(arg);`
// CallOrNewEmitter cone(this, JSOp::Call,
// CallOrNewEmitter::ArgumentsKind::Other,
// ValueUsage::WantValue);
// cone.prepareForOtherCallee();
// emit(some_other_expression);
// cone.emitThis();
// cone.prepareForNonSpreadArguments();
// emit(arg);
// cone.emitEnd(1, Some(offset_of_callee));
//
// `print(...arg);`
// CallOrNewEmitter cone(this, JSOp::SpreadCall,
// CallOrNewEmitter::ArgumentsKind::Other,
// ValueUsage::WantValue);
// cone.emitNameCallee(print);
// cone.emitThis();
// if (cone.wantSpreadOperand()) {
// emit(arg)
// }
// cone.emitSpreadArgumentsTest();
// emit([...arg]);
// cone.emitEnd(1, Some(offset_of_callee));
//
// `print(...rest);`
// where `rest` is rest parameter
// CallOrNewEmitter cone(this, JSOp::SpreadCall,
// CallOrNewEmitter::ArgumentsKind::SingleSpreadRest,
// ValueUsage::WantValue);
// cone.emitNameCallee(print);
// cone.emitThis();
// if (cone.wantSpreadOperand()) {
// emit(arg)
// }
// cone.emitSpreadArgumentsTest();
// emit([...arg]);
// cone.emitEnd(1, Some(offset_of_callee));
//
// `new f(arg);`
// CallOrNewEmitter cone(this, JSOp::New,
// CallOrNewEmitter::ArgumentsKind::Other,
// ValueUsage::WantValue);
// cone.emitNameCallee(f);
// cone.emitThis();
// cone.prepareForNonSpreadArguments();
// emit(arg);
// cone.emitEnd(1, Some(offset_of_callee));
//
class MOZ_STACK_CLASS CallOrNewEmitter {
public:
enum class ArgumentsKind {
Other,
// Specify this for the following case:
//
// function f(...rest) {
// g(...rest);
// }
//
// This enables optimization to avoid allocating an intermediate array
// for spread operation.
//
// wantSpreadOperand() returns true when this is specified.
SingleSpreadRest
};
private:
BytecodeEmitter* bce_;
// The opcode for the call or new.
JSOp op_;
// Whether the call is a spread call with single rest parameter or not.
// See the comment in emitSpreadArgumentsTest for more details.
ArgumentsKind argumentsKind_;
// The branch for spread call optimization.
mozilla::Maybe<InternalIfEmitter> ifNotOptimizable_;
mozilla::Maybe<PropOpEmitter> poe_;
mozilla::Maybe<ElemOpEmitter> eoe_;
// The state of this emitter.
//
// +-------+ emitNameCallee +------------+
// | Start |-+------------------------->| NameCallee |------+
// +-------+ | +------------+ |
// | |
// | prepareForPropCallee +------------+ v
// +------------------------->| PropCallee |----->+
// | +------------+ |
// | |
// | prepareForElemCallee +------------+ v
// +------------------------->| ElemCallee |----->+
// | +------------+ |
// | |
// | prepareForFunctionCallee +----------------+ v
// +------------------------->| FunctionCallee |->+
// | +----------------+ |
// | |
// | emitSuperCallee +-------------+ v
// +------------------------->| SuperCallee |---->+
// | +-------------+ |
// | |
// | prepareForOtherCallee +-------------+ v
// +------------------------->| OtherCallee |---->+
// +-------------+ |
// |
// +--------------------------------------------------------+
// |
// | emitThis +------+
// +--------->| This |-+
// +------+ |
// |
// +-------------------+
// |
// | [!isSpread]
// | prepareForNonSpreadArguments +-----------+ emitEnd +-----+
// +------------------------------->+->| Arguments |-------->| End |
// | ^ +-----------+ +-----+
// | |
// | +----------------------------------+
// | |
// | [isSpread] |
// | wantSpreadOperand +-------------------+ emitSpreadArgumentsTest |
// +-------------------->| WantSpreadOperand |-------------------------+
// +-------------------+
enum class State {
// The initial state.
Start,
// After calling emitNameCallee.
NameCallee,
// After calling prepareForPropCallee.
PropCallee,
// After calling prepareForElemCallee.
ElemCallee,
// After calling prepareForFunctionCallee.
FunctionCallee,
// After calling emitSuperCallee.
SuperCallee,
// After calling prepareForOtherCallee.
OtherCallee,
// After calling emitThis.
This,
// After calling wantSpreadOperand.
WantSpreadOperand,
// After calling prepareForNonSpreadArguments.
Arguments,
// After calling emitEnd.
End
};
State state_ = State::Start;
public:
CallOrNewEmitter(BytecodeEmitter* bce, JSOp op, ArgumentsKind argumentsKind,
ValueUsage valueUsage);
private:
MOZ_MUST_USE bool isCall() const {
return op_ == JSOp::Call || op_ == JSOp::CallIgnoresRv ||
op_ == JSOp::SpreadCall || isEval() || isFunApply() || isFunCall();
}
MOZ_MUST_USE bool isNew() const {
return op_ == JSOp::New || op_ == JSOp::SpreadNew;
}
MOZ_MUST_USE bool isSuperCall() const {
return op_ == JSOp::SuperCall || op_ == JSOp::SpreadSuperCall;
}
MOZ_MUST_USE bool isEval() const {
return op_ == JSOp::Eval || op_ == JSOp::StrictEval ||
op_ == JSOp::SpreadEval || op_ == JSOp::StrictSpreadEval;
}
MOZ_MUST_USE bool isFunApply() const { return op_ == JSOp::FunApply; }
MOZ_MUST_USE bool isFunCall() const { return op_ == JSOp::FunCall; }
MOZ_MUST_USE bool isSpread() const { return JOF_OPTYPE(op_) == JOF_BYTE; }
MOZ_MUST_USE bool isSingleSpreadRest() const {
return argumentsKind_ == ArgumentsKind::SingleSpreadRest;
}
public:
MOZ_MUST_USE bool emitNameCallee(const ParserAtom* name);
MOZ_MUST_USE PropOpEmitter& prepareForPropCallee(bool isSuperProp);
MOZ_MUST_USE ElemOpEmitter& prepareForElemCallee(bool isSuperElem,
bool isPrivateElem);
MOZ_MUST_USE bool prepareForFunctionCallee();
MOZ_MUST_USE bool emitSuperCallee();
MOZ_MUST_USE bool prepareForOtherCallee();
MOZ_MUST_USE bool emitThis();
// Used by BytecodeEmitter::emitPipeline to reuse CallOrNewEmitter instance
// across multiple chained calls.
void reset();
MOZ_MUST_USE bool prepareForNonSpreadArguments();
// See the usage in the comment at the top of the class.
MOZ_MUST_USE bool wantSpreadOperand();
MOZ_MUST_USE bool emitSpreadArgumentsTest();
// Parameters are the offset in the source code for each character below:
//
// callee(arg);
// ^
// |
// beginPos
//
// Can be Nothing() if not available.
MOZ_MUST_USE bool emitEnd(uint32_t argc,
const mozilla::Maybe<uint32_t>& beginPos);
};
} /* namespace frontend */
} /* namespace js */
#endif /* frontend_CallOrNewEmitter_h */
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