CSE2410 Fall 2014 Bounce

// Copyright 2006-2008 the V8 project authors. All rights reserved.

// Redistribution and use in source and binary forms, with or without

// modification, are permitted provided that the following conditions are

// met:

//

//     * Redistributions of source code must retain the above copyright

//       notice, this list of conditions and the following disclaimer.

//     * Redistributions in binary form must reproduce the above

//       copyright notice, this list of conditions and the following

//       disclaimer in the documentation and/or other materials provided

//       with the distribution.

//     * Neither the name of Google Inc. nor the names of its

//       contributors may be used to endorse or promote products derived

//       from this software without specific prior written permission.

//

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#include "v8.h"

#include "frames-inl.h"

namespace v8 { namespace internal {

StackFrame::Type StackFrame::ComputeType(State* state) {

  ASSERT(state->fp != NULL);

  if (StandardFrame::IsArgumentsAdaptorFrame(state->fp)) {

    return ARGUMENTS_ADAPTOR;

  }

  // The marker and function offsets overlap. If the marker isn't a

  // smi then the frame is a JavaScript frame -- and the marker is

  // really the function.

  const int offset = StandardFrameConstants::kMarkerOffset;

  Object* marker = Memory::Object_at(state->fp + offset);

  if (!marker->IsSmi()) return JAVA_SCRIPT;

  return static_cast<StackFrame::Type>(Smi::cast(marker)->value());

}

StackFrame::Type ExitFrame::GetStateForFramePointer(Address fp, State* state) {

  if (fp == 0) return NONE;

  // Compute the stack pointer.

  Address sp = Memory::Address_at(fp + ExitFrameConstants::kSPOffset);

  // Fill in the state.

  state->fp = fp;

  state->sp = sp;

  state->pc_address = reinterpret_cast<Address*>(sp - 1 * kPointerSize);

  // Determine frame type.

  if (Memory::Address_at(fp + ExitFrameConstants::kDebugMarkOffset) != 0) {

    return EXIT_DEBUG;

  } else {

    return EXIT;

  }

}

void ExitFrame::Iterate(ObjectVisitor* v) const {

  // Exit frames on IA-32 do not contain any pointers. The arguments

  // are traversed as part of the expression stack of the calling

  // frame.

}

int JavaScriptFrame::GetProvidedParametersCount() const {

  return ComputeParametersCount();

}

Address JavaScriptFrame::GetCallerStackPointer() const {

  int arguments;

  if (Heap::gc_state() != Heap::NOT_IN_GC || disable_heap_access_) {

    // The arguments for cooked frames are traversed as if they were

    // expression stack elements of the calling frame. The reason for

    // this rather strange decision is that we cannot access the

    // function during mark-compact GCs when the stack is cooked.

    // In fact accessing heap objects (like function->shared() below)

    // at all during GC is problematic.

    arguments = 0;

  } else {

    // Compute the number of arguments by getting the number of formal

    // parameters of the function. We must remember to take the

    // receiver into account (+1).

    JSFunction* function = JSFunction::cast(this->function());

    arguments = function->shared()->formal_parameter_count() + 1;

  }

  const int offset = StandardFrameConstants::kCallerSPOffset;

  return fp() + offset + (arguments * kPointerSize);

}

Address ArgumentsAdaptorFrame::GetCallerStackPointer() const {

  const int arguments = Smi::cast(GetExpression(0))->value();

  const int offset = StandardFrameConstants::kCallerSPOffset;

  return fp() + offset + (arguments + 1) * kPointerSize;

}

Address InternalFrame::GetCallerStackPointer() const {

  // Internal frames have no arguments. The stack pointer of the

  // caller is at a fixed offset from the frame pointer.

  return fp() + StandardFrameConstants::kCallerSPOffset;

}

} }  // namespace v8::internal