libbacktrace/backtrace.h

   1 /* backtrace.h -- Public header file for stack backtrace library.
   2    Copyright (C) 2012-2013 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 #ifndef BACKTRACE_H
  34 #define BACKTRACE_H
  35
  36 #include <stddef.h>
  37 #include <stdio.h>
  38
  39 /* We want to get a definition for uintptr_t, but we still care about
  40    systems that don't have <stdint.h>.  */
  41 #if defined(__GLIBC__) && __GLIBC__ >= 2
  42
  43 #include <stdint.h>
  44
  45 #elif defined(HAVE_STDINT_H)
  46
  47 #include <stdint.h>
  48
  49 #else
  50
  51 /* Systems that don't have <stdint.h> must provide gstdint.h, e.g.,
  52    from GCC_HEADER_STDINT in configure.ac.  */
  53 #include "gstdint.h"
  54
  55 #endif
  56
  57 #ifdef __cplusplus
  58 extern "C" {
  59 #endif
  60
  61 /* The backtrace state.  This struct is intentionally not defined in
  62    the public interface.  */
  63
  64 struct backtrace_state;
  65
  66 /* The type of the error callback argument to backtrace functions.
  67    This function, if not NULL, will be called for certain error cases.
  68    The DATA argument is passed to the function that calls this one.
  69    The MSG argument is an error message.  The ERRNUM argument, if
  70    greater than 0, holds an errno value.  The MSG buffer may become
  71    invalid after this function returns.
  72
  73    As a special case, the ERRNUM argument will be passed as -1 if no
  74    debug info can be found for the executable, but the function
  75    requires debug info (e.g., backtrace_full, backtrace_pcinfo).  The
  76    MSG in this case will be something along the lines of "no debug
  77    info".  Similarly, ERRNUM will be passed as -1 if there is no
  78    symbol table, but the function requires a symbol table (e.g.,
  79    backtrace_syminfo).  This may be used as a signal that some other
  80    approach should be tried.  */
  81
  82 typedef void (*backtrace_error_callback) (void *data, const char *msg,
  83                                           int errnum);
  84
  85 /* Create state information for the backtrace routines.  This must be
  86    called before any of the other routines, and its return value must
  87    be passed to all of the other routines.  FILENAME is the path name
  88    of the executable file; if it is NULL the library will try
  89    system-specific path names.  If not NULL, FILENAME must point to a
  90    permanent buffer.  If THREADED is non-zero the state may be
  91    accessed by multiple threads simultaneously, and the library will
  92    use appropriate locks (this requires that the library be configured
  93    with --enable-backtrace-threads).  If THREADED is zero the state
  94    may only be accessed by one thread at a time.  This returns a state
  95    pointer on success, NULL on error.  If an error occurs, this will
  96    call the ERROR_CALLBACK routine.  */
  97
  98 extern struct backtrace_state *backtrace_create_state (
  99     const char *filename, int threaded,
 100     backtrace_error_callback error_callback, void *data);
 101
 102 /* The type of the callback argument to the backtrace_full function.
 103    DATA is the argument passed to backtrace_full.  PC is the program
 104    counter.  FILENAME is the name of the file containing PC, or NULL
 105    if not available.  LINENO is the line number in FILENAME containing
 106    PC, or 0 if not available.  FUNCTION is the name of the function
 107    containing PC, or NULL if not available.  This should return 0 to
 108    continuing tracing.  The FILENAME and FUNCTION buffers may become
 109    invalid after this function returns.  */
 110
 111 typedef int (*backtrace_full_callback) (void *data, uintptr_t pc,
 112                                         const char *filename, int lineno,
 113                                         const char *function);
 114
 115 /* Get a full stack backtrace.  SKIP is the number of frames to skip;
 116    passing 0 will start the trace with the function calling
 117    backtrace_full.  DATA is passed to the callback routine.  If any
 118    call to CALLBACK returns a non-zero value, the stack backtrace
 119    stops, and backtrace returns that value; this may be used to limit
 120    the number of stack frames desired.  If all calls to CALLBACK
 121    return 0, backtrace returns 0.  The backtrace_full function will
 122    make at least one call to either CALLBACK or ERROR_CALLBACK.  This
 123    function requires debug info for the executable.  */
 124
 125 extern int backtrace_full (struct backtrace_state *state, int skip,
 126                            backtrace_full_callback callback,
 127                            backtrace_error_callback error_callback,
 128                            void *data);
 129
 130 /* The type of the callback argument to the backtrace_simple function.
 131    DATA is the argument passed to simple_backtrace.  PC is the program
 132    counter.  This should return 0 to continue tracing.  */
 133
 134 typedef int (*backtrace_simple_callback) (void *data, uintptr_t pc);
 135
 136 /* Get a simple backtrace.  SKIP is the number of frames to skip, as
 137    in backtrace.  DATA is passed to the callback routine.  If any call
 138    to CALLBACK returns a non-zero value, the stack backtrace stops,
 139    and backtrace_simple returns that value.  Otherwise
 140    backtrace_simple returns 0.  The backtrace_simple function will
 141    make at least one call to either CALLBACK or ERROR_CALLBACK.  This
 142    function does not require any debug info for the executable.  */
 143
 144 extern int backtrace_simple (struct backtrace_state *state, int skip,
 145                              backtrace_simple_callback callback,
 146                              backtrace_error_callback error_callback,
 147                              void *data);
 148
 149 /* Print the current backtrace in a user readable format to a FILE.
 150    SKIP is the number of frames to skip, as in backtrace_full.  Any
 151    error messages are printed to stderr.  This function requires debug
 152    info for the executable.  */
 153
 154 extern void backtrace_print (struct backtrace_state *state, int skip, FILE *);
 155
 156 /* Given PC, a program counter in the current program, call the
 157    callback function with filename, line number, and function name
 158    information.  This will normally call the callback function exactly
 159    once.  However, if the PC happens to describe an inlined call, and
 160    the debugging information contains the necessary information, then
 161    this may call the callback function multiple times.  This will make
 162    at least one call to either CALLBACK or ERROR_CALLBACK.  This
 163    returns the first non-zero value returned by CALLBACK, or 0.  */
 164
 165 extern int backtrace_pcinfo (struct backtrace_state *state, uintptr_t pc,
 166                              backtrace_full_callback callback,
 167                              backtrace_error_callback error_callback,
 168                              void *data);
 169
 170 /* The type of the callback argument to backtrace_syminfo.  DATA and
 171    PC are the arguments passed to backtrace_syminfo.  SYMNAME is the
 172    name of the symbol for the corresponding code.  SYMVAL is the
 173    value.  SYMNAME will be NULL if no error occurred but the symbol
 174    could not be found.  */
 175
 176 typedef void (*backtrace_syminfo_callback) (void *data, uintptr_t pc,
 177                                             const char *symname,
 178                                             uintptr_t symval);
 179
 180 /* Given PC, a program counter in the current program, call the
 181    callback information with the symbol name and value describing the
 182    function in which PC may be found.  This will call either CALLBACK
 183    or ERROR_CALLBACK exactly once.  This returns 1 on success, 0 on
 184    failure.  This function requires the symbol table but does not
 185    require the debug info.  Note that if the symbol table is present
 186    but PC could not be found in the table, CALLBACK will be called
 187    with a NULL SYMNAME argument.  Returns 1 on success, 0 on
 188    error.  */
 189
 190 extern int backtrace_syminfo (struct backtrace_state *state, uintptr_t pc,
 191                               backtrace_syminfo_callback callback,
 192                               backtrace_error_callback error_callback,
 193                               void *data);
 194
 195 #ifdef __cplusplus
 196 } /* End extern "C".  */
 197 #endif
 198
 199 #endif