github.com/axw/llgo@v0.0.0-20160805011314-95b5fe4dca20/third_party/gofrontend/libbacktrace/simple.c (about)

     1  /* simple.c -- The backtrace_simple function.
     2     Copyright (C) 2012-2015 Free Software Foundation, Inc.
     3     Written by Ian Lance Taylor, Google.
     4  
     5  Redistribution and use in source and binary forms, with or without
     6  modification, are permitted provided that the following conditions are
     7  met:
     8  
     9      (1) Redistributions of source code must retain the above copyright
    10      notice, this list of conditions and the following disclaimer. 
    11  
    12      (2) Redistributions in binary form must reproduce the above copyright
    13      notice, this list of conditions and the following disclaimer in
    14      the documentation and/or other materials provided with the
    15      distribution.  
    16      
    17      (3) The name of the author may not be used to
    18      endorse or promote products derived from this software without
    19      specific prior written permission.
    20  
    21  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
    22  IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
    23  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
    24  DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
    25  INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
    26  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
    27  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
    28  HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
    29  STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
    30  IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    31  POSSIBILITY OF SUCH DAMAGE.  */
    32  
    33  #include "config.h"
    34  
    35  #include "unwind.h"
    36  #include "backtrace.h"
    37  
    38  /* The simple_backtrace routine.  */
    39  
    40  /* Data passed through _Unwind_Backtrace.  */
    41  
    42  struct backtrace_simple_data
    43  {
    44    /* Number of frames to skip.  */
    45    int skip;
    46    /* Library state.  */
    47    struct backtrace_state *state;
    48    /* Callback routine.  */
    49    backtrace_simple_callback callback;
    50    /* Error callback routine.  */
    51    backtrace_error_callback error_callback;
    52    /* Data to pass to callback routine.  */
    53    void *data;
    54    /* Value to return from backtrace.  */
    55    int ret;
    56  };
    57  
    58  /* Unwind library callback routine.  This is passd to
    59     _Unwind_Backtrace.  */
    60  
    61  static _Unwind_Reason_Code
    62  simple_unwind (struct _Unwind_Context *context, void *vdata)
    63  {
    64    struct backtrace_simple_data *bdata = (struct backtrace_simple_data *) vdata;
    65    uintptr_t pc;
    66    int ip_before_insn = 0;
    67  
    68  #ifdef HAVE_GETIPINFO
    69    pc = _Unwind_GetIPInfo (context, &ip_before_insn);
    70  #else
    71    pc = _Unwind_GetIP (context);
    72  #endif
    73  
    74    if (bdata->skip > 0)
    75      {
    76        --bdata->skip;
    77        return _URC_NO_REASON;
    78      }
    79  
    80    if (!ip_before_insn)
    81      --pc;
    82  
    83    bdata->ret = bdata->callback (bdata->data, pc);
    84  
    85    if (bdata->ret != 0)
    86      return _URC_END_OF_STACK;
    87  
    88    return _URC_NO_REASON;
    89  }
    90  
    91  /* Get a simple stack backtrace.  */
    92  
    93  int
    94  backtrace_simple (struct backtrace_state *state, int skip,
    95  		  backtrace_simple_callback callback,
    96  		  backtrace_error_callback error_callback, void *data)
    97  {
    98    struct backtrace_simple_data bdata;
    99  
   100    bdata.skip = skip + 1;
   101    bdata.state = state;
   102    bdata.callback = callback;
   103    bdata.error_callback = error_callback;
   104    bdata.data = data;
   105    bdata.ret = 0;
   106    _Unwind_Backtrace (simple_unwind, &bdata);
   107    return bdata.ret;
   108  }