backtrace.h

/*
 * Copyright (C) 2011 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
 
/* A stack unwinder. */
 
#ifndef _CORKSCREW_BACKTRACE_H
#define _CORKSCREW_BACKTRACE_H
 
#ifdef __cplusplus
extern "C"
{
#endif
 
#include <sys/types.h>
#include <corkscrew/ptrace.h>
#include <corkscrew/map_info.h>
#include <corkscrew/symbol_table.h>
 
  /*
   * Describes a single frame of a backtrace.
   */
  typedef struct
  {
    uintptr_t absolute_pc; /* absolute PC offset */
    uintptr_t stack_top;   /* top of stack for this frame */
    size_t stack_size;     /* size of this stack frame */
  } backtrace_frame_t;
 
  /*
   * Describes the symbols associated with a backtrace frame.
   */
  typedef struct
  {
    uintptr_t relative_pc;          /* relative frame PC offset from the start of the library,
                                   or the absolute PC if the library is unknown */
    uintptr_t relative_symbol_addr; /* relative offset of the symbol from the start of the
                                library or 0 if the library is unknown */
    char* map_name;                 /* executable or library name, or NULL if unknown */
    char* symbol_name;              /* symbol name, or NULL if unknown */
    char* demangled_name;           /* demangled symbol name, or NULL if unknown */
  } backtrace_symbol_t;
 
  /*
   * Unwinds the call stack for the current thread of execution.
   * Populates the backtrace array with the program counters from the call stack.
   * Returns the number of frames collected, or -1 if an error occurred.
   */
  ssize_t unwind_backtrace(backtrace_frame_t* backtrace, size_t ignore_depth, size_t max_depth);
 
  /*
   * Unwinds the call stack for a thread within this process.
   * Populates the backtrace array with the program counters from the call stack.
   * Returns the number of frames collected, or -1 if an error occurred.
   *
   * The task is briefly suspended while the backtrace is being collected.
   */
  ssize_t unwind_backtrace_thread(pid_t tid, backtrace_frame_t* backtrace, size_t ignore_depth,
                                  size_t max_depth);
 
  /*
   * Unwinds the call stack of a task within a remote process using ptrace().
   * Populates the backtrace array with the program counters from the call stack.
   * Returns the number of frames collected, or -1 if an error occurred.
   */
  ssize_t unwind_backtrace_ptrace(pid_t tid, const ptrace_context_t* context,
                                  backtrace_frame_t* backtrace, size_t ignore_depth,
                                  size_t max_depth);
 
  /*
   * Gets the symbols for each frame of a backtrace.
   * The symbols array must be big enough to hold one symbol record per frame.
   * The symbols must later be freed using free_backtrace_symbols.
   */
  void get_backtrace_symbols(const backtrace_frame_t* backtrace, size_t frames,
                             backtrace_symbol_t* backtrace_symbols);
 
  /*
   * Gets the symbols for each frame of a backtrace from a remote process.
   * The symbols array must be big enough to hold one symbol record per frame.
   * The symbols must later be freed using free_backtrace_symbols.
   */
  void get_backtrace_symbols_ptrace(const ptrace_context_t* context,
                                    const backtrace_frame_t* backtrace, size_t frames,
                                    backtrace_symbol_t* backtrace_symbols);
 
  /*
   * Frees the storage associated with backtrace symbols.
   */
  void free_backtrace_symbols(backtrace_symbol_t* backtrace_symbols, size_t frames);
 
  enum
  {
    // A hint for how big to make the line buffer for format_backtrace_line
    MAX_BACKTRACE_LINE_LENGTH = 800,
  };
 
  void format_backtrace_line(unsigned frameNumber, const backtrace_frame_t* frame,
                             const backtrace_symbol_t* symbol, char* buffer, size_t bufferSize);
 
#ifdef __cplusplus
}
#endif
 
#endif // _CORKSCREW_BACKTRACE_H