Add facility to suppress/capture tor_bug_occurred_() messages in unit tests.

src/common/util_bug.c

@@ -11,6 +11,44 @@
 #include "util_bug.h"
 #include "torlog.h"
 #include "backtrace.h"
+#include "container.h"
+
+#ifdef TOR_UNIT_TESTS
+static int n_bugs_to_capture = 0;
+static smartlist_t *bug_messages = NULL;
+#define capturing_bugs() (bug_messages != NULL && n_bugs_to_capture)
+void
+tor_capture_bugs_(int n)
+{
+  tor_end_capture_bugs_();
+  bug_messages = smartlist_new();
+  n_bugs_to_capture = n;
+}
+void
+tor_end_capture_bugs_(void)
+{
+  n_bugs_to_capture = 0;
+  if (!bug_messages)
+    return;
+  SMARTLIST_FOREACH(bug_messages, char *, cp, tor_free(cp));
+  smartlist_free(bug_messages);
+  bug_messages = NULL;
+}
+const smartlist_t *
+tor_get_captured_bug_log_(void)
+{
+  return bug_messages;
+}
+static void
+add_captured_bug(const char *s)
+{
+  --n_bugs_to_capture;
+  smartlist_add(bug_messages, tor_strdup(s));
+}
+#else
+#define capturing_bugs() (0)
+#define add_captured_bug(s) do { } while (0)
+#endif
 
 /** Helper for tor_assert: report the assertion failure. */
 void
@@ -36,12 +74,20 @@ tor_bug_occurred_(const char *fname, unsigned int line,
   const char *once_str = once ?
     " (Future instances of this warning will be silenced.)": "";
   if (! expr) {
+    if (capturing_bugs()) {
+      add_captured_bug("This line should not have been reached.");
+      return;
+    }
     log_warn(LD_BUG, "%s:%u: %s: This line should not have been reached.%s",
              fname, line, func, once_str);
     tor_snprintf(buf, sizeof(buf),
                  "Line unexpectedly reached at %s at %s:%u",
                  func, fname, line);
   } else {
+    if (capturing_bugs()) {
+      add_captured_bug(expr);
+      return;
+    }
     log_warn(LD_BUG, "%s:%u: %s: Non-fatal assertion %s failed.%s",
              fname, line, func, expr, once_str);
     tor_snprintf(buf, sizeof(buf),

src/common/util_bug.h

@@ -149,5 +149,11 @@ void tor_bug_occurred_(const char *fname, unsigned int line,
                        const char *func, const char *expr,
                        int once);
 
+#ifdef TOR_UNIT_TESTS
+void tor_capture_bugs_(int n);
+void tor_end_capture_bugs_(void);
+const struct smartlist_t *tor_get_captured_bug_log_(void);
+#endif
+
 #endif