sysrap/tests/UnwindTest.cc

0001 /*
0002  * Copyright (c) 2019 Opticks Team. All Rights Reserved.
0003  *
0004  * This file is part of Opticks
0005  * (see https://bitbucket.org/simoncblyth/opticks).
0006  *
0007  * Licensed under the Apache License, Version 2.0 (the "License");
0008  * you may not use this file except in compliance with the License.
0009  * You may obtain a copy of the License at
0010  *
0011  *   http://www.apache.org/licenses/LICENSE-2.0
0012  *
0013  * Unless required by applicable law or agreed to in writing, software
0014  * distributed under the License is distributed on an "AS IS" BASIS,
0015  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
0016  * See the License for the specific language governing permissions and
0017  * limitations under the License.
0018  */
0019
0020 // https://eli.thegreenplace.net/2015/programmatic-access-to-the-call-stack-in-c/
0021
0022 #include "OPTICKS_LOG.hh"
0023
0024 #define UNW_LOCAL_ONLY
0025 #include <libunwind.h>
0026 #include <stdio.h>
0027
0028 // Call this function to get a backtrace.
0029 void backtrace() {
0030   unw_cursor_t cursor;
0031   unw_context_t context;
0032
0033   // Initialize cursor to current frame for local unwinding.
0034   unw_getcontext(&context);
0035   unw_init_local(&cursor, &context);
0036
0037   // Unwind frames one by one, going up the frame stack.
0038   while (unw_step(&cursor) > 0) {
0039     unw_word_t offset, pc;
0040     unw_get_reg(&cursor, UNW_REG_IP, &pc);
0041     if (pc == 0) {
0042       break;
0043     }
0044     printf("0x%llx:", pc);
0045
0046     char sym[256];
0047     if (unw_get_proc_name(&cursor, sym, sizeof(sym), &offset) == 0) {
0048       printf(" (%s+0x%llx)\n", sym, offset);
0049     } else {
0050       printf(" -- error: unable to obtain symbol name for this frame\n");
0051     }
0052   }
0053 }
0054
0055 void foo() {
0056   backtrace(); // <-------- backtrace here!
0057 }
0058
0059 void bar() {
0060   foo();
0061 }
0062
0063 int main(int argc, char **argv)
0064 {
0065     OPTICKS_LOG(argc, argv );
0066
0067     bar();
0068
0069     return 0;
0070 }