/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-

 * vim: set ts=8 sts=4 et sw=4 tw=99:

 * 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 jit_BytecodeAnalysis_h

#define jit_BytecodeAnalysis_h

#include "jit/JitAllocPolicy.h"

#include "js/Vector.h"

#include "vm/JSScript.h"

namespace js {

namespace jit {

// Basic information about bytecodes in the script.  Used to help baseline compilation.

struct BytecodeInfo

{

    static const uint16_t MAX_STACK_DEPTH = 0xffffU;

    uint16_t stackDepth;

    bool initialized : 1;

    bool jumpTarget : 1;

    // If true, this is a JSOP_LOOPENTRY op inside a catch or finally block.

    bool loopEntryInCatchOrFinally : 1;

    void init(unsigned depth) {

        MOZ_ASSERT(depth <= MAX_STACK_DEPTH);

        MOZ_ASSERT_IF(initialized, stackDepth == depth);

        initialized = true;

        stackDepth = depth;

    }

};

class BytecodeAnalysis

{

    JSScript* script_;

    Vector<BytecodeInfo, 0, JitAllocPolicy> infos_;

    bool usesEnvironmentChain_;

    bool hasTryFinally_;

  public:

    explicit BytecodeAnalysis(TempAllocator& alloc, JSScript* script);

    MOZ_MUST_USE bool init(TempAllocator& alloc, GSNCache& gsn);

    BytecodeInfo& info(jsbytecode* pc) {

        MOZ_ASSERT(infos_[script_->pcToOffset(pc)].initialized);

        return infos_[script_->pcToOffset(pc)];

    }

    BytecodeInfo* maybeInfo(jsbytecode* pc) {

        if (infos_[script_->pcToOffset(pc)].initialized) {

            return &infos_[script_->pcToOffset(pc)];

        }

        return nullptr;

    }

    bool usesEnvironmentChain() const {

        return usesEnvironmentChain_;

    }

    bool hasTryFinally() const {

        return hasTryFinally_;

    }

};

} // namespace jit

} // namespace js

#endif /* jit_BytecodeAnalysis_h */