//===-- sanitizer_stacktrace.h ----------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file is shared between AddressSanitizer and ThreadSanitizer
// run-time libraries.
//===----------------------------------------------------------------------===//
#ifndef SANITIZER_STACKTRACE_H
#define SANITIZER_STACKTRACE_H

#include "sanitizer_internal_defs.h"

namespace __sanitizer {

static const uptr kStackTraceMax = 256;

#if SANITIZER_LINUX && (defined(__aarch64__) || defined(__powerpc__) || \
                        defined(__powerpc64__) || defined(__sparc__) || \
                        defined(__mips__))
# define SANITIZER_CAN_FAST_UNWIND 0
#elif SANITIZER_WINDOWS
# define SANITIZER_CAN_FAST_UNWIND 0
#else
# define SANITIZER_CAN_FAST_UNWIND 1
#endif

struct StackTrace {
  typedef bool (*SymbolizeCallback)(const void *pc, char *out_buffer,
                                     int out_size);
  uptr top_frame_bp;
  uptr size;
  uptr trace[kStackTraceMax];

  // Prints a symbolized stacktrace, followed by an empty line.
  static void PrintStack(const uptr *addr, uptr size);
  void Print() const {
    PrintStack(trace, size);
  }

  void CopyFrom(const uptr *src, uptr src_size) {
    top_frame_bp = 0;
    size = src_size;
    if (size > kStackTraceMax) size = kStackTraceMax;
    for (uptr i = 0; i < size; i++)
      trace[i] = src[i];
  }

  static bool WillUseFastUnwind(bool request_fast_unwind) {
    // Check if fast unwind is available. Fast unwind is the only option on Mac.
    // It is also the only option on FreeBSD as the slow unwinding that
    // leverages _Unwind_Backtrace() yields the call stack of the signal's
    // handler and not of the code that raised the signal (as it does on Linux).
    if (!SANITIZER_CAN_FAST_UNWIND)
      return false;
    else if (SANITIZER_MAC != 0 || SANITIZER_FREEBSD != 0)
      return true;
    return request_fast_unwind;
  }

  void Unwind(uptr max_depth, uptr pc, uptr bp, void *context, uptr stack_top,
              uptr stack_bottom, bool request_fast_unwind);

  static uptr GetCurrentPc();
  static uptr GetPreviousInstructionPc(uptr pc);

 private:
  void FastUnwindStack(uptr pc, uptr bp, uptr stack_top, uptr stack_bottom,
                       uptr max_depth);
  void SlowUnwindStack(uptr pc, uptr max_depth);
  void SlowUnwindStackWithContext(uptr pc, void *context,
                                  uptr max_depth);
  void PopStackFrames(uptr count);
  uptr LocatePcInTrace(uptr pc);
};

}  // namespace __sanitizer

// Use this macro if you want to print stack trace with the caller
// of the current function in the top frame.
#define GET_CALLER_PC_BP_SP \
  uptr bp = GET_CURRENT_FRAME();              \
  uptr pc = GET_CALLER_PC();                  \
  uptr local_stack;                           \
  uptr sp = (uptr)&local_stack

// Use this macro if you want to print stack trace with the current
// function in the top frame.
#define GET_CURRENT_PC_BP_SP \
  uptr bp = GET_CURRENT_FRAME();              \
  uptr pc = StackTrace::GetCurrentPc();   \
  uptr local_stack;                           \
  uptr sp = (uptr)&local_stack


#endif  // SANITIZER_STACKTRACE_H
