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