build: define _GNU_SOURCE only on the command line

Not in source files

See https://ariadne.space/2021/12/21/stop-defining-feature-test-macros-in-your-code/

Signed-off-by: Steve Bennett <steveb@workware.net.au>

6 files changed, 2 insertions, 24 deletions

diff --git a/auto.def b/auto.def
index e9d6002..36ab1e3 100644
--- a/auto.def
+++ b/auto.def
@@ -209,6 +209,8 @@ cc-check-sizeof int
 # Default optimisation
 define-append AS_CPPFLAGS -O2
 
+define-append AS_CPPFLAGS -D_GNU_SOURCE
+
 # check, but don't add to -cflags
 cc-with {} {
     cc-check-flags -fno-unwind-tables -fno-asynchronous-unwind-tables
diff --git a/jim-aio.c b/jim-aio.c
index cb56826..487f2c3 100644
--- a/jim-aio.c
+++ b/jim-aio.c
@@ -39,9 +39,6 @@
 
 #include "jimautoconf.h"
 
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <stdio.h>
 #include <string.h>
 #include <errno.h>
diff --git a/jim-clock.c b/jim-clock.c
index 43d7f74..1b03935 100644
--- a/jim-clock.c
+++ b/jim-clock.c
@@ -6,18 +6,6 @@
 
 #include "jimautoconf.h"
 
-/* For strptime() - currently nothing sets this */
-#ifdef STRPTIME_NEEDS_XOPEN_SOURCE
-#ifndef _XOPEN_SOURCE
-#define _XOPEN_SOURCE 500
-#endif
-#endif
-
-/* For timegm() */
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
-
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
diff --git a/jim-exec.c b/jim-exec.c
index 36edb92..69a7841 100644
--- a/jim-exec.c
+++ b/jim-exec.c
@@ -20,9 +20,6 @@
  * express or implied warranty.
  */
 
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <string.h>
 #include <ctype.h>
 
diff --git a/jim-tty.c b/jim-tty.c
index 6fbb346..b3faaba 100644
--- a/jim-tty.c
+++ b/jim-tty.c
@@ -6,9 +6,6 @@
  */
 
 /* termios support is required */
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <jim-tty.h>
 #include <termios.h>
 
diff --git a/jim.c b/jim.c
index ea60e10..f4fd955 100644
--- a/jim.c
+++ b/jim.c
@@ -41,9 +41,6 @@
  * official policies, either expressed or implied, of the Jim Tcl Project.
  **/
 #define JIM_OPTIMIZATION        /* comment to avoid optimizations and reduce size */
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE             /* Mostly just for environ */
-#endif
 
 #include <stdio.h>
 #include <stdlib.h>