1 /* backtrace.h -- Public header file for stack backtrace library. 2 Copyright (C) 2012-2020 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 206