Remove the dependency on MBEDTLS_HAVE_TIME from MBEDTLS_TIMING_C

The timing module might include time.h on its own when on 
a suitable platform, even if MBEDTLS_HAVE_TIME is disabled. 


Co-authored-by: Tom Cosgrove <tom.cosgrove@arm.com>
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>

include/mbedtls/mbedtls_config.h

@@ -129,7 +129,12 @@
  * MBEDTLS_PLATFORM_TIME_MACRO, MBEDTLS_PLATFORM_TIME_TYPE_MACRO and
  * MBEDTLS_PLATFORM_STD_TIME.
  *
- * Comment if your system does not support time functions
+ * Comment if your system does not support time functions.
+ *
+ * \note If MBEDTLS_TIMING_C is set - to enable the semi-portable timing
+ *       interface - timing.c will include time.h on suitable platforms
+ *       regardless of the setting of MBEDTLS_HAVE_TIME, unless
+ *       MBEDTLS_TIMING_ALT is used. See timing.c for more information.
  */
 #define MBEDTLS_HAVE_TIME
 
@@ -3013,6 +3018,10 @@
  * your own implementation of the whole module by setting
  * \c MBEDTLS_TIMING_ALT in the current file.
  *
+ * \note The timing module will include time.h on suitable platforms
+ *       regardless of the setting of MBEDTLS_HAVE_TIME, unless
+ *       MBEDTLS_TIMING_ALT is used. See timing.c for more information.
+ *
  * \note See also our Knowledge Base article about porting to a new
  * environment:
  * https://tls.mbed.org/kb/how-to/how-do-i-port-mbed-tls-to-a-new-environment-OS

library/timing.c

@@ -46,14 +46,14 @@ struct _hr_time
 #include <unistd.h>
 #include <sys/types.h>
 #include <signal.h>
-#if defined(MBEDTLS_HAVE_TIME)
+/* time.h should be included independently of MBEDTLS_HAVE_TIME. If the
+ * platform matches the ifdefs above, it will be used. */
 #include <time.h>
 #include <sys/time.h>
 struct _hr_time
 {
     struct timeval start;
 };
-#endif
 #endif /* _WIN32 && !EFIX64 && !EFI32 */
 
 /**
@@ -75,7 +75,6 @@ struct _hr_time
  *                 get_timer(0) }` the value time1+time2 is only approximately
  *                 the delay since the first reset.
  */
-#if defined(MBEDTLS_HAVE_TIME)
 #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
 
 unsigned long mbedtls_timing_get_timer( struct mbedtls_timing_hr_time *val, int reset )
@@ -167,6 +166,5 @@ uint32_t mbedtls_timing_get_final_delay(
 {
     return( data->fin_ms );
 }
-#endif /* MBEDTLS_HAVE_TIME */
 #endif /* !MBEDTLS_TIMING_ALT */
 #endif /* MBEDTLS_TIMING_C */

tests/suites/test_suite_timing.data

@@ -1,11 +1,8 @@
 Timing: get timer
-depends_on:MBEDTLS_HAVE_TIME
 timing_get_timer:
 
 Timing: delay 0ms
-depends_on:MBEDTLS_HAVE_TIME
 timing_delay:0:
 
 Timing: delay 100ms
-depends_on:MBEDTLS_HAVE_TIME
 timing_delay:100: