tvhlog: add tvhlog_backtrace_printf() helper for debugging

src/tvhlog.c

@@ -23,6 +23,10 @@
 #include <stdlib.h>
 #include <sys/time.h>
 
+#if ENABLE_EXECINFO
+#include <execinfo.h>
+#endif
+
 #include "libav.h"
 #include "webui/webui.h"
 
@@ -399,6 +403,27 @@ _tvhlog_hexdump(const char *file, int line,
   }
 }
 
+/*
+ *
+ */
+void
+tvhlog_backtrace_printf(const char *fmt, ...)
+{
+#if ENABLE_EXECINFO
+  static void *frames[5];
+  int nframes = backtrace(frames, 5), i;
+  char **strings = backtrace_symbols(frames, nframes);
+  va_list args;
+
+  va_start(args, fmt);
+  vprintf(fmt, args);
+  va_end(args);
+  for (i = 0; i < nframes; i++)
+    printf("  %s\n", strings[i]);
+  free(strings);
+#endif
+}
+
 /*
  * Initialise
  */

src/tvhlog.h

@@ -131,4 +131,6 @@ static inline void tvhtrace_no_warnings(const char *fmt, ...) { (void)fmt; }
 
 time_t dispatch_clock_update(struct timespec *ts);
 
+void tvhlog_backtrace_printf(const char *fmt, ...);
+
 #endif /* __TVH_LOGGING_H__ */