libbacktrace/backtrace.h

   1 /* backtrace.h -- Public header file for stack backtrace library.
   2    Copyright (C) 2012-2019 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 atomic operations.  If THREADED is zero the state
  93    may only be accessed by one thread at a time.  This returns a state
  94    pointer on success, NULL on error.  If an error occurs, this will
  95    call the ERROR_CALLBACK routine.
  96
  97    Calling this function allocates resources that cannot be freed.
  98    There is no backtrace_free_state function.  The state is used to
  99    cache information that is expensive to recompute.  Programs are
 100    expected to call this function at most once and to save the return
 101    value for all later calls to backtrace functions.  */
 102
 103 extern struct backtrace_state *backtrace_create_state (
 104     const char *filename, int threaded,
 105     backtrace_error_callback error_callback, void *data);
 106
 107 /* The type of the callback argument to the backtrace_full function.
 108    DATA is the argument passed to backtrace_full.  PC is the program
 109    counter.  FILENAME is the name of the file containing PC, or NULL
 110    if not available.  LINENO is the line number in FILENAME containing
 111    PC, or 0 if not available.  FUNCTION is the name of the function
 112    containing PC, or NULL if not available.  This should return 0 to
 113    continuing tracing.  The FILENAME and FUNCTION buffers may become
 114    invalid after this function returns.  */
 115
 116 typedef int (*backtrace_full_callback) (void *data, uintptr_t pc,
 117                                         const char *filename, int lineno,
 118                                         const char *function);
 119
 120 /* Get a full stack backtrace.  SKIP is the number of frames to skip;
 121    passing 0 will start the trace with the function calling
 122    backtrace_full.  DATA is passed to the callback routine.  If any
 123    call to CALLBACK returns a non-zero value, the stack backtrace
 124    stops, and backtrace returns that value; this may be used to limit
 125    the number of stack frames desired.  If all calls to CALLBACK
 126    return 0, backtrace returns 0.  The backtrace_full function will
 127    make at least one call to either CALLBACK or ERROR_CALLBACK.  This
 128    function requires debug info for the executable.  */
 129
 130 extern int backtrace_full (struct backtrace_state *state, int skip,
 131                            backtrace_full_callback callback,
 132                            backtrace_error_callback error_callback,
 133                            void *data);
 134
 135 /* The type of the callback argument to the backtrace_simple function.
 136    DATA is the argument passed to simple_backtrace.  PC is the program
 137    counter.  This should return 0 to continue tracing.  */
 138
 139 typedef int (*backtrace_simple_callback) (void *data, uintptr_t pc);
 140
 141 /* Get a simple backtrace.  SKIP is the number of frames to skip, as
 142    in backtrace.  DATA is passed to the callback routine.  If any call
 143    to CALLBACK returns a non-zero value, the stack backtrace stops,
 144    and backtrace_simple returns that value.  Otherwise
 145    backtrace_simple returns 0.  The backtrace_simple function will
 146    make at least one call to either CALLBACK or ERROR_CALLBACK.  This
 147    function does not require any debug info for the executable.  */
 148
 149 extern int backtrace_simple (struct backtrace_state *state, int skip,
 150                              backtrace_simple_callback callback,
 151                              backtrace_error_callback error_callback,
 152                              void *data);
 153
 154 /* Print the current backtrace in a user readable format to a FILE.
 155    SKIP is the number of frames to skip, as in backtrace_full.  Any
 156    error messages are printed to stderr.  This function requires debug
 157    info for the executable.  */
 158
 159 extern void backtrace_print (struct backtrace_state *state, int skip, FILE *);
 160
 161 /* Given PC, a program counter in the current program, call the
 162    callback function with filename, line number, and function name
 163    information.  This will normally call the callback function exactly
 164    once.  However, if the PC happens to describe an inlined call, and
 165    the debugging information contains the necessary information, then
 166    this may call the callback function multiple times.  This will make
 167    at least one call to either CALLBACK or ERROR_CALLBACK.  This
 168    returns the first non-zero value returned by CALLBACK, or 0.  */
 169
 170 extern int backtrace_pcinfo (struct backtrace_state *state, uintptr_t pc,
 171                              backtrace_full_callback callback,
 172                              backtrace_error_callback error_callback,
 173                              void *data);
 174
 175 /* The type of the callback argument to backtrace_syminfo.  DATA and
 176    PC are the arguments passed to backtrace_syminfo.  SYMNAME is the
 177    name of the symbol for the corresponding code.  SYMVAL is the
 178    value and SYMSIZE is the size of the symbol.  SYMNAME will be NULL
 179    if no error occurred but the symbol could not be found.  */
 180
 181 typedef void (*backtrace_syminfo_callback) (void *data, uintptr_t pc,
 182                                             const char *symname,
 183                                             uintptr_t symval,
 184                                             uintptr_t symsize);
 185
 186 /* Given ADDR, an address or program counter in the current program,
 187    call the callback information with the symbol name and value
 188    describing the function or variable in which ADDR may be found.
 189    This will call either CALLBACK or ERROR_CALLBACK exactly once.
 190    This returns 1 on success, 0 on failure.  This function requires
 191    the symbol table but does not require the debug info.  Note that if
 192    the symbol table is present but ADDR could not be found in the
 193    table, CALLBACK will be called with a NULL SYMNAME argument.
 194    Returns 1 on success, 0 on error.  */
 195
 196 extern int backtrace_syminfo (struct backtrace_state *state, uintptr_t addr,
 197                               backtrace_syminfo_callback callback,
 198                               backtrace_error_callback error_callback,
 199                               void *data);
 200
 201 #ifdef __cplusplus
 202 } /* End extern "C".  */
 203 #endif
 204
 205 #endif