time64.[ch]: Inline only use of another macro

This macro is now only used once.  It is accessible outside perl because
it is in time64.h, but isn't used in cpan.  Remove it and place its
expansion in time64.c.

Part of the expansion called another function.  That function can be
removed and the expansion simplified, since gmtime() is now
automatically converted into gmtime_r() if available and needed.

2 files changed, 21 insertions, 30 deletions

diff --git a/time64.c b/time64.c
index 6c75c482cf..dfd5776e3a 100644
--- a/time64.c
+++ b/time64.c
@@ -289,28 +289,6 @@ static void S_copy_little_tm_to_big_TM(const struct tm *src, struct TM *dest) {
 #endif
 }
 
-
-#ifndef HAS_GMTIME_R
-/* Simulate gmtime_r() to the best of our ability */
-static struct tm * S_gmtime_r(const time_t *clock, struct tm *result) {
-#ifdef __VMS
-    dTHX;    /* the following is defined as Perl_my_localtime(aTHX_ ...) */
-#endif
-    const struct tm * const static_result = gmtime(clock);
-
-    assert(result != NULL);
-
-    if( static_result == NULL ) {
-        memset(result, 0, sizeof(*result));
-        return NULL;
-    }
-    else {
-        memcpy(result, static_result, sizeof(*result));
-        return result;
-    }
-}
-#endif
-
 struct TM *Perl_gmtime64_r (const Time64_T *in_time, struct TM *p)
 {
     int v_tm_sec, v_tm_min, v_tm_hour, v_tm_mon, v_tm_wday;
@@ -319,6 +297,7 @@ struct TM *Perl_gmtime64_r (const Time64_T *in_time, struct TM *p)
     Time64_T m;
     Time64_T time = *in_time;
     Year year = 70;
+    dTHX;
 
     assert(p != NULL);
 
@@ -326,9 +305,27 @@ struct TM *Perl_gmtime64_r (const Time64_T *in_time, struct TM *p)
     if( SHOULD_USE_SYSTEM_GMTIME(*in_time) ) {
         time_t safe_time = (time_t)*in_time;
         struct tm safe_date;
-        GMTIME_R(&safe_time, &safe_date);
+        struct tm * result;
+
+        /* reentr.h will automatically replace this with a call to gmtime_r()
+         * when appropriate */
+        result = gmtime(&safe_time);
+
+        assert(result != NULL);
+
+#if defined(HAS_GMTIME_R) && defined(USE_REENTRANT_API)
+
+        PERL_UNUSED_VAR(safe_date);
+#else
+        /* Here, no gmtime_r() and is a threaded perl where the result can be
+         * overwritten by a call in another thread.  Copy to a safe place,
+         * hopefully before another gmtime can jump in and trash this
+         * result. */
+        memcpy(&safe_date, result, sizeof(safe_date));
+        result = &safe_date;
+#endif
 
-        S_copy_little_tm_to_big_TM(&safe_date, p);
+        S_copy_little_tm_to_big_TM(result, p);
         assert(S_check_tm(p));
 
         return p;
diff --git a/time64.h b/time64.h
index 4da148b9aa..b86e771602 100644
--- a/time64.h
+++ b/time64.h
@@ -53,10 +53,4 @@ struct TM64 {
 struct TM *Perl_gmtime64_r    (const Time64_T *, struct TM *);
 struct TM *Perl_localtime64_r (const Time64_T *, struct TM *);
 
-/* Not everyone has gmtime_r(), provide a replacement */
-#ifdef HAS_GMTIME_R
-#    define GMTIME_R(clock, result)    gmtime_r(clock, result)
-#else
-#    define GMTIME_R(clock, result)    S_gmtime_r(clock, result)
-#endif
 #endif