src/lib/log/util_bug.c

   1 /* Copyright (c) 2003, Roger Dingledine
   2  * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
   3  * Copyright (c) 2007-2019, The Tor Project, Inc. */
   4 /* See LICENSE for licensing information */
   5
   6 /**
   7  * \file util_bug.c
   8  **/
   9
  10 #include "orconfig.h"
  11 #include "lib/log/util_bug.h"
  12 #include "lib/log/log.h"
  13 #include "lib/err/backtrace.h"
  14 #ifdef TOR_UNIT_TESTS
  15 #include "lib/smartlist_core/smartlist_core.h"
  16 #include "lib/smartlist_core/smartlist_foreach.h"
  17 #endif
  18 #include "lib/malloc/malloc.h"
  19 #include "lib/string/printf.h"
  20
  21 #include <string.h>
  22
  23 #ifdef TOR_UNIT_TESTS
  24 static void (*failed_assertion_cb)(void) = NULL;
  25 static int n_bugs_to_capture = 0;
  26 static smartlist_t *bug_messages = NULL;
  27 #define capturing_bugs() (bug_messages != NULL && n_bugs_to_capture)
  28 void
  29 tor_capture_bugs_(int n)
  30 {
  31   tor_end_capture_bugs_();
  32   bug_messages = smartlist_new();
  33   n_bugs_to_capture = n;
  34 }
  35 void
  36 tor_end_capture_bugs_(void)
  37 {
  38   n_bugs_to_capture = 0;
  39   if (!bug_messages)
  40     return;
  41   SMARTLIST_FOREACH(bug_messages, char *, cp, tor_free(cp));
  42   smartlist_free(bug_messages);
  43   bug_messages = NULL;
  44 }
  45 const smartlist_t *
  46 tor_get_captured_bug_log_(void)
  47 {
  48   return bug_messages;
  49 }
  50 static void
  51 add_captured_bug(const char *s)
  52 {
  53   --n_bugs_to_capture;
  54   smartlist_add_strdup(bug_messages, s);
  55 }
  56 /** Set a callback to be invoked when we get any tor_bug_occurred_
  57  * invocation. We use this in the unit tests so that a nonfatal
  58  * assertion failure can also count as a test failure.
  59  */
  60 void
  61 tor_set_failed_assertion_callback(void (*fn)(void))
  62 {
  63   failed_assertion_cb = fn;
  64 }
  65 #else /* !(defined(TOR_UNIT_TESTS)) */
  66 #define capturing_bugs() (0)
  67 #define add_captured_bug(s) do { } while (0)
  68 #endif /* defined(TOR_UNIT_TESTS) */
  69
  70 /** Helper for tor_assert: report the assertion failure. */
  71 void
  72 tor_assertion_failed_(const char *fname, unsigned int line,
  73                       const char *func, const char *expr)
  74 {
  75   char buf[256];
  76   log_err(LD_BUG, "%s:%u: %s: Assertion %s failed; aborting.",
  77           fname, line, func, expr);
  78   tor_snprintf(buf, sizeof(buf),
  79                "Assertion %s failed in %s at %s:%u",
  80                expr, func, fname, line);
  81   log_backtrace(LOG_ERR, LD_BUG, buf);
  82 }
  83
  84 /** Helper for tor_assert_nonfatal: report the assertion failure. */
  85 void
  86 tor_bug_occurred_(const char *fname, unsigned int line,
  87                   const char *func, const char *expr,
  88                   int once)
  89 {
  90   char buf[256];
  91   const char *once_str = once ?
  92     " (Future instances of this warning will be silenced.)": "";
  93   if (! expr) {
  94     if (capturing_bugs()) {
  95       add_captured_bug("This line should not have been reached.");
  96       return;
  97     }
  98     log_warn(LD_BUG, "%s:%u: %s: This line should not have been reached.%s",
  99              fname, line, func, once_str);
 100     tor_snprintf(buf, sizeof(buf),
 101                  "Line unexpectedly reached at %s at %s:%u",
 102                  func, fname, line);
 103   } else {
 104     if (capturing_bugs()) {
 105       add_captured_bug(expr);
 106       return;
 107     }
 108     log_warn(LD_BUG, "%s:%u: %s: Non-fatal assertion %s failed.%s",
 109              fname, line, func, expr, once_str);
 110     tor_snprintf(buf, sizeof(buf),
 111                  "Non-fatal assertion %s failed in %s at %s:%u",
 112                  expr, func, fname, line);
 113   }
 114   log_backtrace(LOG_WARN, LD_BUG, buf);
 115
 116 #ifdef TOR_UNIT_TESTS
 117   if (failed_assertion_cb) {
 118     failed_assertion_cb();
 119   }
 120 #endif
 121 }
 122
 123 #ifdef _WIN32
 124 /** Take a filename and return a pointer to its final element.  This
 125  * function is called on __FILE__ to fix a MSVC nit where __FILE__
 126  * contains the full path to the file.  This is bad, because it
 127  * confuses users to find the home directory of the person who
 128  * compiled the binary in their warning messages.
 129  */
 130 const char *
 131 tor_fix_source_file(const char *fname)
 132 {
 133   const char *cp1, *cp2, *r;
 134   cp1 = strrchr(fname, '/');
 135   cp2 = strrchr(fname, '\\');
 136   if (cp1 && cp2) {
 137     r = (cp1<cp2)?(cp2+1):(cp1+1);
 138   } else if (cp1) {
 139     r = cp1+1;
 140   } else if (cp2) {
 141     r = cp2+1;
 142   } else {
 143     r = fname;
 144   }
 145   return r;
 146 }
 147 #endif /* defined(_WIN32) */