1 /* backtrace.h -- Public header file for stack backtrace library. 2 Copyright (C) 2012-2022 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, or if the debug info 75 exists but has an unsupported version, but the function requires 76 debug info (e.g., backtrace_full, backtrace_pcinfo). The MSG in 77 this case will be something along the lines of "no debug info". 78 Similarly, ERRNUM will be passed as -1 if there is no symbol table, 79 but the function requires a symbol table (e.g., backtrace_syminfo). 80 This may be used as a signal that some other approach should be 81 tried. */ 82 83 typedef void (*backtrace_error_callback) (void *data, const char *msg, 84 int errnum); 85 86 /* Create state information for the backtrace routines. This must be 87 called before any of the other routines, and its return value must 88 be passed to all of the other routines. FILENAME is the path name 89 of the executable file; if it is NULL the library will try 90 system-specific path names. If not NULL, FILENAME must point to a 91 permanent buffer. If THREADED is non-zero the state may be 92 accessed by multiple threads simultaneously, and the library will 93 use appropriate atomic operations. 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 Calling this function allocates resources that cannot be freed. 99 There is no backtrace_free_state function. The state is used to 100 cache information that is expensive to recompute. Programs are 101 expected to call this function at most once and to save the return 102 value for all later calls to backtrace functions. */ 103 104 extern struct backtrace_state *backtrace_create_state ( 105 const char *filename, int threaded, 106 backtrace_error_callback error_callback, void *data); 107 108 /* The type of the callback argument to the backtrace_full function. 109 DATA is the argument passed to backtrace_full. PC is the program 110 counter. FILENAME is the name of the file containing PC, or NULL 111 if not available. LINENO is the line number in FILENAME containing 112 PC, or 0 if not available. FUNCTION is the name of the function 113 containing PC, or NULL if not available. This should return 0 to 114 continuing tracing. The FILENAME and FUNCTION buffers may become 115 invalid after this function returns. */ 116 117 typedef int (*backtrace_full_callback) (void *data, uintptr_t pc, 118 const char *filename, int lineno, 119 const char *function); 120 121 /* Get a full stack backtrace. SKIP is the number of frames to skip; 122 passing 0 will start the trace with the function calling 123 backtrace_full. DATA is passed to the callback routine. If any 124 call to CALLBACK returns a non-zero value, the stack backtrace 125 stops, and backtrace returns that value; this may be used to limit 126 the number of stack frames desired. If all calls to CALLBACK 127 return 0, backtrace returns 0. The backtrace_full function will 128 make at least one call to either CALLBACK or ERROR_CALLBACK. This 129 function requires debug info for the executable. */ 130 131 extern int backtrace_full (struct backtrace_state *state, int skip, 132 backtrace_full_callback callback, 133 backtrace_error_callback error_callback, 134 void *data); 135 136 /* The type of the callback argument to the backtrace_simple function. 137 DATA is the argument passed to simple_backtrace. PC is the program 138 counter. This should return 0 to continue tracing. */ 139 140 typedef int (*backtrace_simple_callback) (void *data, uintptr_t pc); 141 142 /* Get a simple backtrace. SKIP is the number of frames to skip, as 143 in backtrace. DATA is passed to the callback routine. If any call 144 to CALLBACK returns a non-zero value, the stack backtrace stops, 145 and backtrace_simple returns that value. Otherwise 146 backtrace_simple returns 0. The backtrace_simple function will 147 make at least one call to either CALLBACK or ERROR_CALLBACK. This 148 function does not require any debug info for the executable. */ 149 150 extern int backtrace_simple (struct backtrace_state *state, int skip, 151 backtrace_simple_callback callback, 152 backtrace_error_callback error_callback, 153 void *data); 154 155 /* Print the current backtrace in a user readable format to a FILE. 156 SKIP is the number of frames to skip, as in backtrace_full. Any 157 error messages are printed to stderr. This function requires debug 158 info for the executable. */ 159 160 extern void backtrace_print (struct backtrace_state *state, int skip, FILE *); 161 162 /* Given PC, a program counter in the current program, call the 163 callback function with filename, line number, and function name 164 information. This will normally call the callback function exactly 165 once. However, if the PC happens to describe an inlined call, and 166 the debugging information contains the necessary information, then 167 this may call the callback function multiple times. This will make 168 at least one call to either CALLBACK or ERROR_CALLBACK. This 169 returns the first non-zero value returned by CALLBACK, or 0. */ 170 171 extern int backtrace_pcinfo (struct backtrace_state *state, uintptr_t pc, 172 backtrace_full_callback callback, 173 backtrace_error_callback error_callback, 174 void *data); 175 176 /* The type of the callback argument to backtrace_syminfo. DATA and 177 PC are the arguments passed to backtrace_syminfo. SYMNAME is the 178 name of the symbol for the corresponding code. SYMVAL is the 179 value and SYMSIZE is the size of the symbol. SYMNAME will be NULL 180 if no error occurred but the symbol could not be found. */ 181 182 typedef void (*backtrace_syminfo_callback) (void *data, uintptr_t pc, 183 const char *symname, 184 uintptr_t symval, 185 uintptr_t symsize); 186 187 /* Given ADDR, an address or program counter in the current program, 188 call the callback information with the symbol name and value 189 describing the function or variable in which ADDR may be found. 190 This will call either CALLBACK or ERROR_CALLBACK exactly once. 191 This returns 1 on success, 0 on failure. This function requires 192 the symbol table but does not require the debug info. Note that if 193 the symbol table is present but ADDR could not be found in the 194 table, CALLBACK will be called with a NULL SYMNAME argument. 195 Returns 1 on success, 0 on error. */ 196 197 extern int backtrace_syminfo (struct backtrace_state *state, uintptr_t addr, 198 backtrace_syminfo_callback callback, 199 backtrace_error_callback error_callback, 200 void *data); 201 202 #ifdef __cplusplus 203 } /* End extern "C". */ 204 #endif 205 206 #endif 207