// -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*-
// Copyright (c) 2005, Google Inc.
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//
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// ---
// Author: Sanjay Ghemawat
//
// Portable implementation - just use glibc
//
// Note:  The glibc implementation may cause a call to malloc.
// This can cause a deadlock in HeapProfiler.

#ifndef BASE_STACKTRACE_GENERIC_INL_H_
#define BASE_STACKTRACE_GENERIC_INL_H_
// Note: this file is included into stacktrace.cc more than once.
// Anything that should only be defined once should be here:

#include <execinfo.h>
#include <string.h>
#include "gperftools/stacktrace.h"
#endif  // BASE_STACKTRACE_GENERIC_INL_H_

// Note: this part of the file is included several times.
// Do not put globals below.

// The following 4 functions are generated from the code below:
//   GetStack{Trace,Frames}()
//   GetStack{Trace,Frames}WithContext()
//
// These functions take the following args:
//   void** result: the stack-trace, as an array
//   int* sizes: the size of each stack frame, as an array
//               (GetStackFrames* only)
//   int max_depth: the size of the result (and sizes) array(s)
//   int skip_count: how many stack pointers to skip before storing in result
//   void* ucp: a ucontext_t* (GetStack{Trace,Frames}WithContext only)
static int GET_STACK_TRACE_OR_FRAMES {
  static const int kStackLength = 64;
  void * stack[kStackLength];
  int size;

  size = backtrace(stack, kStackLength);
  skip_count += 2;  // we want to skip the current and it's parent frame as well
  int result_count = size - skip_count;
  if (result_count < 0)
    result_count = 0;
  if (result_count > max_depth)
    result_count = max_depth;
  for (int i = 0; i < result_count; i++)
    result[i] = stack[i + skip_count];

#if IS_STACK_FRAMES
  // No implementation for finding out the stack frame sizes yet.
  memset(sizes, 0, sizeof(*sizes) * result_count);
#endif

  return result_count;
}
