src/lib/log/util_bug.c

   1 /* Copyright (c) 2003, Roger Dingledine
   2  * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
   3  * Copyright (c) 2007-2021, 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 #include "lib/err/torerr.h"
  15 #ifdef TOR_UNIT_TESTS
  16 #include "lib/smartlist_core/smartlist_core.h"
  17 #include "lib/smartlist_core/smartlist_foreach.h"
  18 #endif
  19 #include "lib/malloc/malloc.h"
  20 #include "lib/string/printf.h"
  21
  22 #include <string.h>
  23 #include <stdlib.h>
  24
  25 #ifdef TOR_UNIT_TESTS
  26 static void (*failed_assertion_cb)(void) = NULL;
  27 static int n_bugs_to_capture = 0;
  28 static smartlist_t *bug_messages = NULL;
  29 #define capturing_bugs() (bug_messages != NULL && n_bugs_to_capture)
  30 void
  31 tor_capture_bugs_(int n)
  32 {
  33   tor_end_capture_bugs_();
  34   bug_messages = smartlist_new();
  35   n_bugs_to_capture = n;
  36 }
  37 void
  38 tor_end_capture_bugs_(void)
  39 {
  40   n_bugs_to_capture = 0;
  41   if (!bug_messages)
  42     return;
  43   SMARTLIST_FOREACH(bug_messages, char *, cp, tor_free(cp));
  44   smartlist_free(bug_messages);
  45   bug_messages = NULL;
  46 }
  47 const smartlist_t *
  48 tor_get_captured_bug_log_(void)
  49 {
  50   return bug_messages;
  51 }
  52 static void
  53 add_captured_bug(const char *s)
  54 {
  55   --n_bugs_to_capture;
  56   smartlist_add_strdup(bug_messages, s);
  57 }
  58 /** Set a callback to be invoked when we get any tor_bug_occurred_
  59  * invocation. We use this in the unit tests so that a nonfatal
  60  * assertion failure can also count as a test failure.
  61  */
  62 void
  63 tor_set_failed_assertion_callback(void (*fn)(void))
  64 {
  65   failed_assertion_cb = fn;
  66 }
  67 #else /* !defined(TOR_UNIT_TESTS) */
  68 #define capturing_bugs() (0)
  69 #define add_captured_bug(s) do { } while (0)
  70 #endif /* defined(TOR_UNIT_TESTS) */
  71
  72 /** Helper for tor_assert: report the assertion failure. */
  73 void
  74 tor_assertion_failed_(const char *fname, unsigned int line,
  75                       const char *func, const char *expr,
  76                       const char *fmt, ...)
  77 {
  78   char *buf = NULL;
  79   char *extra = NULL;
  80   va_list ap;
  81
  82 #ifdef __clang__
  83 #pragma clang diagnostic push
  84 #pragma clang diagnostic ignored "-Wformat-nonliteral"
  85 #endif
  86   if (fmt) {
  87     va_start(ap,fmt);
  88     tor_vasprintf(&extra, fmt, ap);
  89     va_end(ap);
  90   }
  91 #ifdef __clang__
  92 #pragma clang diagnostic pop
  93 #endif
  94
  95   log_err(LD_BUG, "%s:%u: %s: Assertion %s failed; aborting.",
  96           fname, line, func, expr);
  97   tor_asprintf(&buf, "Assertion %s failed in %s at %s:%u: %s",
  98                expr, func, fname, line, extra ? extra : "");
  99   tor_free(extra);
 100   log_backtrace(LOG_ERR, LD_BUG, buf);
 101   tor_free(buf);
 102 }
 103
 104 /** Helper for tor_assert_nonfatal: report the assertion failure. */
 105 void
 106 tor_bug_occurred_(const char *fname, unsigned int line,
 107                   const char *func, const char *expr,
 108                   int once, const char *fmt, ...)
 109 {
 110   char *buf = NULL;
 111   const char *once_str = once ?
 112     " (Future instances of this warning will be silenced.)": "";
 113   if (! expr) {
 114     if (capturing_bugs()) {
 115       add_captured_bug("This line should not have been reached.");
 116       return;
 117     }
 118     log_warn(LD_BUG, "%s:%u: %s: This line should not have been reached.%s",
 119              fname, line, func, once_str);
 120     tor_asprintf(&buf,
 121                  "Line unexpectedly reached at %s at %s:%u",
 122                  func, fname, line);
 123   } else {
 124     if (capturing_bugs()) {
 125       add_captured_bug(expr);
 126       return;
 127     }
 128
 129     va_list ap;
 130     char *extra = NULL;
 131
 132 #ifdef __clang__
 133 #pragma clang diagnostic push
 134 #pragma clang diagnostic ignored "-Wformat-nonliteral"
 135 #endif
 136     if (fmt) {
 137       va_start(ap,fmt);
 138       tor_vasprintf(&extra, fmt, ap);
 139       va_end(ap);
 140     }
 141 #ifdef __clang__
 142 #pragma clang diagnostic pop
 143 #endif
 144
 145     log_warn(LD_BUG, "%s:%u: %s: Non-fatal assertion %s failed.%s",
 146              fname, line, func, expr, once_str);
 147     tor_asprintf(&buf, "Non-fatal assertion %s failed in %s at %s:%u%s%s",
 148                  expr, func, fname, line, fmt ? " : " : "",
 149                  extra ? extra : "");
 150     tor_free(extra);
 151   }
 152   log_backtrace(LOG_WARN, LD_BUG, buf);
 153   tor_free(buf);
 154
 155 #ifdef TOR_UNIT_TESTS
 156   if (failed_assertion_cb) {
 157     failed_assertion_cb();
 158   }
 159 #endif
 160 }
 161
 162 /**
 163  * Call the tor_raw_abort_() function to close raw logs, then kill the current
 164  * process with a fatal error. But first, close the file-based log file
 165  * descriptors, so error messages are written before process termination.
 166  *
 167  * (This is a separate function so that we declare it in util_bug.h without
 168  * including torerr.h in all the users of util_bug.h)
 169  **/
 170 void
 171 tor_abort_(void)
 172 {
 173   logs_flush_sigsafe();
 174   tor_raw_abort_();
 175 }
 176
 177 #ifdef _WIN32
 178 /** Take a filename and return a pointer to its final element.  This
 179  * function is called on __FILE__ to fix a MSVC nit where __FILE__
 180  * contains the full path to the file.  This is bad, because it
 181  * confuses users to find the home directory of the person who
 182  * compiled the binary in their warning messages.
 183  */
 184 const char *
 185 tor_fix_source_file(const char *fname)
 186 {
 187   const char *cp1, *cp2, *r;
 188   cp1 = strrchr(fname, '/');
 189   cp2 = strrchr(fname, '\\');
 190   if (cp1 && cp2) {
 191     r = (cp1<cp2)?(cp2+1):(cp1+1);
 192   } else if (cp1) {
 193     r = cp1+1;
 194   } else if (cp2) {
 195     r = cp2+1;
 196   } else {
 197     r = fname;
 198   }
 199   return r;
 200 }
 201 #endif /* defined(_WIN32) */