1 /* backtrace.h -- Public header file for stack backtrace library. 2 Copyright (C) 2012-2018 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 extern struct backtrace_state *backtrace_create_state ( 98 const char *filename, int threaded, 99 backtrace_error_callback error_callback, void *data); 100 101 /* The type of the callback argument to the backtrace_full function. 102 DATA is the argument passed to backtrace_full. PC is the program 103 counter. FILENAME is the name of the file containing PC, or NULL 104 if not available. LINENO is the line number in FILENAME containing 105 PC, or 0 if not available. FUNCTION is the name of the function 106 containing PC, or NULL if not available. This should return 0 to 107 continuing tracing. The FILENAME and FUNCTION buffers may become 108 invalid after this function returns. */ 109 110 typedef int (*backtrace_full_callback) (void *data, uintptr_t pc, 111 const char *filename, int lineno, 112 const char *function); 113 114 /* Get a full stack backtrace. SKIP is the number of frames to skip; 115 passing 0 will start the trace with the function calling 116 backtrace_full. DATA is passed to the callback routine. If any 117 call to CALLBACK returns a non-zero value, the stack backtrace 118 stops, and backtrace returns that value; this may be used to limit 119 the number of stack frames desired. If all calls to CALLBACK 120 return 0, backtrace returns 0. The backtrace_full function will 121 make at least one call to either CALLBACK or ERROR_CALLBACK. This 122 function requires debug info for the executable. */ 123 124 extern int backtrace_full (struct backtrace_state *state, int skip, 125 backtrace_full_callback callback, 126 backtrace_error_callback error_callback, 127 void *data); 128 129 /* The type of the callback argument to the backtrace_simple function. 130 DATA is the argument passed to simple_backtrace. PC is the program 131 counter. This should return 0 to continue tracing. */ 132 133 typedef int (*backtrace_simple_callback) (void *data, uintptr_t pc); 134 135 /* Get a simple backtrace. SKIP is the number of frames to skip, as 136 in backtrace. DATA is passed to the callback routine. If any call 137 to CALLBACK returns a non-zero value, the stack backtrace stops, 138 and backtrace_simple returns that value. Otherwise 139 backtrace_simple returns 0. The backtrace_simple function will 140 make at least one call to either CALLBACK or ERROR_CALLBACK. This 141 function does not require any debug info for the executable. */ 142 143 extern int backtrace_simple (struct backtrace_state *state, int skip, 144 backtrace_simple_callback callback, 145 backtrace_error_callback error_callback, 146 void *data); 147 148 /* Print the current backtrace in a user readable format to a FILE. 149 SKIP is the number of frames to skip, as in backtrace_full. Any 150 error messages are printed to stderr. This function requires debug 151 info for the executable. */ 152 153 extern void backtrace_print (struct backtrace_state *state, int skip, FILE *); 154 155 /* Given PC, a program counter in the current program, call the 156 callback function with filename, line number, and function name 157 information. This will normally call the callback function exactly 158 once. However, if the PC happens to describe an inlined call, and 159 the debugging information contains the necessary information, then 160 this may call the callback function multiple times. This will make 161 at least one call to either CALLBACK or ERROR_CALLBACK. This 162 returns the first non-zero value returned by CALLBACK, or 0. */ 163 164 extern int backtrace_pcinfo (struct backtrace_state *state, uintptr_t pc, 165 backtrace_full_callback callback, 166 backtrace_error_callback error_callback, 167 void *data); 168 169 /* The type of the callback argument to backtrace_syminfo. DATA and 170 PC are the arguments passed to backtrace_syminfo. SYMNAME is the 171 name of the symbol for the corresponding code. SYMVAL is the 172 value and SYMSIZE is the size of the symbol. SYMNAME will be NULL 173 if no error occurred but the symbol could not be found. */ 174 175 typedef void (*backtrace_syminfo_callback) (void *data, uintptr_t pc, 176 const char *symname, 177 uintptr_t symval, 178 uintptr_t symsize); 179 180 /* Given ADDR, an address or program counter in the current program, 181 call the callback information with the symbol name and value 182 describing the function or variable in which ADDR may be found. 183 This will call either CALLBACK or ERROR_CALLBACK exactly once. 184 This returns 1 on success, 0 on failure. This function requires 185 the symbol table but does not require the debug info. Note that if 186 the symbol table is present but ADDR could not be found in the 187 table, CALLBACK will be called with a NULL SYMNAME argument. 188 Returns 1 on success, 0 on error. */ 189 190 extern int backtrace_syminfo (struct backtrace_state *state, uintptr_t addr, 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 200