Add timestamps to GC logs

ocaml/runtime/caml/osdeps.h

@@ -108,6 +108,9 @@ extern char_os *caml_secure_getenv(char_os const *var);
    cannot be determined, return -1. */
 extern int caml_num_rows_fd(int fd);
 
+/* Print a timestamp for verbose GC logs */
+extern void caml_print_timestamp(FILE* channel, int formatted);
+
 #ifdef _WIN32
 
 extern int caml_win32_rename(const wchar_t *, const wchar_t *);

ocaml/runtime/misc.c

@@ -70,6 +70,9 @@ void caml_gc_message (int level, char *msg, ...)
   if ((caml_verb_gc & level) != 0){
     va_list ap;
     va_start(ap, msg);
+    if (caml_verb_gc & 0x1000) {
+      caml_print_timestamp(stderr, caml_verb_gc & 0x2000);
+    }
     vfprintf (stderr, msg, ap);
     va_end(ap);
     fflush (stderr);

ocaml/runtime/unix.c

@@ -29,6 +29,8 @@
 #include <errno.h>
 #include <sys/ioctl.h>
 #include <fcntl.h>
+#include <sys/time.h>
+#include <time.h>
 #include "caml/config.h"
 #if defined(SUPPORT_DYNAMIC_LINKING) && !defined(BUILDING_LIBCAMLRUNS)
 #define WITH_DYNAMIC_LINKING
@@ -434,3 +436,32 @@ int caml_num_rows_fd(int fd)
   return -1;
 #endif
 }
+
+void caml_print_timestamp(FILE* channel, int formatted)
+{
+  struct timeval tv;
+  gettimeofday(&tv, NULL);
+  if (!formatted) {
+    fprintf(channel, "%ld.%06d ", (long)tv.tv_sec, (int)tv.tv_usec);
+  } else {
+    struct tm tm;
+    char tz[10] = "Z";
+    localtime_r(&tv.tv_sec, &tm);
+    if (tm.tm_gmtoff != 0) {
+      long tzhour = tm.tm_gmtoff / 60 / 60;
+      long tzmin = (tm.tm_gmtoff / 60) % 60;
+      if (tzmin < 0) {tzmin += 60; tzhour--;}
+      sprintf(tz, "%+03ld:%02ld", tzhour, tzmin);
+    }
+    fprintf(channel,
+            "[%04d-%02d-%02d %02d:%02d:%02d.%06d%s] ",
+            1900 + tm.tm_year,
+            tm.tm_mon + 1,
+            tm.tm_mday,
+            tm.tm_hour,
+            tm.tm_min,
+            tm.tm_sec,
+            (int)tv.tv_usec,
+            tz);
+  }
+}

ocaml/runtime/win32.c

@@ -1065,6 +1065,11 @@ int caml_num_rows_fd(int fd)
   return -1;
 }
 
+void caml_print_timestamp(FILE* channel, int formatted)
+{
+  /* unimplemented */
+}
+
 /* UCRT clock function returns wall-clock time */
 CAMLexport clock_t caml_win32_clock(void)
 {