text: // 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"
  #include "arm/assembler-arm-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 frame type and stack pointer.
    Address sp = fp + ExitFrameConstants::kSPDisplacement;
    Type type;
    if (Memory::Address_at(fp + ExitFrameConstants::kDebugMarkOffset) != 0) {
      type = EXIT_DEBUG;
      sp -= kNumJSCallerSaved * kPointerSize;
    } else {
      type = EXIT;
    }
    // Fill in the state.
    state->sp = sp;
    state->fp = fp;
    state->pc_address = reinterpret_cast<Address*>(sp - 1 * kPointerSize);
    return type;
  }
  
  
  void ExitFrame::Iterate(ObjectVisitor* v) const {
    // Do nothing
  }
  
  
  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
  