From 0d314c4a04ef1b86a1ea66107b2d1a8d1bcd93b9 Mon Sep 17 00:00:00 2001
From: Simon Ser <contact@emersion.fr>
Date: Mon, 10 Jan 2022 14:51:55 +0100
Subject: [PATCH] build: don't rely on implicit GNU extensions

Currently libwayland assumes GNU extensions will be available, but
doesn't define the C standard to use. Instead, let's unconditionally
enable POSIX extensions, and enable GNU extensions on a case-by-case
basis as needed.

Signed-off-by: Simon Ser <contact@emersion.fr>
---
 cursor/xcursor.c        |  1 +
 meson.build             | 10 ++++++++--
 tests/display-test.c    |  1 +
 tests/event-loop-test.c |  1 +
 tests/fixed-test.c      |  1 +
 5 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/cursor/xcursor.c b/cursor/xcursor.c
index 0506680..188be7c 100644
--- a/cursor/xcursor.c
+++ b/cursor/xcursor.c
@@ -23,6 +23,7 @@
  * SOFTWARE.
  */
 
+#define _GNU_SOURCE
 #include "xcursor.h"
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/meson.build b/meson.build
index 07bbd29..cab267e 100644
--- a/meson.build
+++ b/meson.build
@@ -14,6 +14,12 @@ config_h = configuration_data()
 config_h.set_quoted('PACKAGE', meson.project_name())
 config_h.set_quoted('PACKAGE_VERSION', meson.project_version())
 
+cc_args = []
+if host_machine.system() != 'freebsd'
+	cc_args += ['-D_POSIX_C_SOURCE=200809L']
+endif
+add_project_arguments(cc_args, language: 'c')
+
 compiler_flags = [
 	'-Wno-unused-parameter',
 	'-Wstrict-prototypes',
@@ -79,7 +85,7 @@ if get_option('libraries')
 	]
 
 	foreach d: decls
-		if not cc.has_header_symbol(d['header'], d['symbol'], dependencies: epoll_dep)
+		if not cc.has_header_symbol(d['header'], d['symbol'], dependencies: epoll_dep, args: cc_args)
 			error('@0@ is needed to compile Wayland libraries'.format(d['symbol']))
 		endif
 	endforeach
@@ -87,7 +93,7 @@ if get_option('libraries')
 	rt_dep = []
 	if not cc.has_function('clock_gettime', prefix: '#include <time.h>')
 		rt_dep = cc.find_library('rt')
-		if not cc.has_function('clock_gettime', prefix: '#include <time.h>', dependencies: rt_dep)
+		if not cc.has_function('clock_gettime', prefix: '#include <time.h>', dependencies: rt_dep, args: cc_args)
 			error('clock_gettime not found')
 		endif
 	endif
diff --git a/tests/display-test.c b/tests/display-test.c
index 763adc9..a6f410d 100644
--- a/tests/display-test.c
+++ b/tests/display-test.c
@@ -24,6 +24,7 @@
  * SOFTWARE.
  */
 
+#define _GNU_SOURCE
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/tests/event-loop-test.c b/tests/event-loop-test.c
index 9d43c91..a51ba8f 100644
--- a/tests/event-loop-test.c
+++ b/tests/event-loop-test.c
@@ -24,6 +24,7 @@
  * SOFTWARE.
  */
 
+#define _GNU_SOURCE
 #include <stdlib.h>
 #include <stdint.h>
 #include <assert.h>
diff --git a/tests/fixed-test.c b/tests/fixed-test.c
index 47a4dae..0b58797 100644
--- a/tests/fixed-test.c
+++ b/tests/fixed-test.c
@@ -23,6 +23,7 @@
  * SOFTWARE.
  */
 
+#define _GNU_SOURCE
 #include <stdlib.h>
 #include <stdio.h>
 #include <assert.h>