Remove gmnow() helper fxn from ros3 VFD

Replace with gmtime(time(NULL))

The unused pointer arg in time() is obsolescent and should be NULL
in new code. When the pointer is NULL, the time call cannot fail.

src/H5FDros3.c

@@ -750,8 +750,8 @@ H5FD__ros3_open(const char *url, unsigned flags, hid_t fapl_id, haddr_t maxaddr)
          *
          * TODO: Find way to reuse/share?
          */
-        now = gmnow();
-        assert(now != NULL);
+        if (NULL == (now = gmtime(time(NULL))))
+            HGOTO_ERROR(H5E_VFL, H5E_BADVALUE, NULL, "gmtime() error");
         if (ISO8601NOW(iso8601now, now) != (ISO8601_SIZE - 1))
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "problem while writing iso8601 timestamp");
         if (FAIL == H5FD_s3comms_signing_key(signing_key, (const char *)fa->secret_key,

src/H5FDs3comms.c

@@ -1211,7 +1211,8 @@ H5FD_s3comms_s3r_read(s3r_t *handle, haddr_t offset, size_t len, void *dest)
         if (request == NULL)
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "could not allocate hrb_t request.");
 
-        now = gmnow();
+        if (NULL == (now = gmtime(time(NULL))))
+            HGOTO_ERROR(H5E_VFL, H5E_BADVALUE, FAIL, "gmtime() error");
         if (ISO8601NOW(iso8601now, now) != (ISO8601_SIZE - 1))
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "could not format ISO8601 time.");
 
@@ -1394,37 +1395,6 @@ H5FD_s3comms_s3r_read(s3r_t *handle, haddr_t offset, size_t len, void *dest)
  * MISCELLANEOUS FUNCTIONS
  ****************************************************************************/
 
-/*----------------------------------------------------------------------------
- *
- * Function: gmnow()
- *
- * Purpose:
- *
- *    Get the output of `time.h`'s `gmtime()` call while minimizing setup
- *    clutter where important.
- *
- * Return:
- *
- *    Pointer to resulting `struct tm`,as created by gmtime(time_t * T).
- *
- *----------------------------------------------------------------------------
- */
-struct tm *
-gmnow(void)
-{
-    time_t     now;
-    time_t    *now_ptr   = &now;
-    struct tm *ret_value = NULL;
-
-    /* Doctor assert, checks against error in time() */
-    if ((time_t)(-1) != time(now_ptr))
-        ret_value = gmtime(now_ptr);
-
-    assert(ret_value != NULL);
-
-    return ret_value;
-} /* end gmnow() */
-
 /*----------------------------------------------------------------------------
  *
  * Function: H5FD_s3comms_aws_canonical_request()

src/H5FDs3comms.h

@@ -452,23 +452,23 @@ typedef struct {
 extern "C" {
 #endif
 
-/*******************************************
- * DECLARATION OF HTTP FIELD LIST ROUTINES *
- *******************************************/
+/****************************
+ * HTTP FIELD LIST ROUTINES *
+ ****************************/
 
 H5_DLL herr_t H5FD_s3comms_hrb_node_set(hrb_node_t **L, const char *name, const char *value);
 
-/***********************************************
- * DECLARATION OF HTTP REQUEST BUFFER ROUTINES *
- ***********************************************/
+/********************************
+ * HTTP REQUEST BUFFER ROUTINES *
+ ********************************/
 
 H5_DLL herr_t H5FD_s3comms_hrb_destroy(hrb_t **buf);
 
 H5_DLL hrb_t *H5FD_s3comms_hrb_init_request(const char *verb, const char *resource, const char *host);
 
-/*************************************
- * DECLARATION OF S3REQUEST ROUTINES *
- *************************************/
+/**********************
+ * S3REQUEST ROUTINES *
+ **********************/
 
 H5_DLL herr_t H5FD_s3comms_s3r_close(s3r_t *handle);
 
@@ -479,11 +479,9 @@ H5_DLL s3r_t *H5FD_s3comms_s3r_open(const char url[], const char region[], const
 
 H5_DLL herr_t H5FD_s3comms_s3r_read(s3r_t *handle, haddr_t offset, size_t len, void *dest);
 
-/*********************************
- * DECLARATION OF OTHER ROUTINES *
- *********************************/
-
-H5_DLL struct tm *gmnow(void);
+/******************
+ * OTHER ROUTINES *
+ ******************/
 
 H5_DLL herr_t H5FD_s3comms_aws_canonical_request(char *canonical_request_dest, int cr_size,
                                                  char *signed_headers_dest, int sh_size, hrb_t *http_request);

test/s3comms.c

@@ -1477,7 +1477,7 @@ test_s3r_open(void)
             TEST_ERROR;
     }
 
-    if (NULL == (now = gmnow()))
+    if (NULL == (now = gmtime(time(NULL))))
         TEST_ERROR;
     if (ISO8601NOW(iso8601now, now) != (ISO8601_SIZE - 1))
         TEST_ERROR;