From 92b18462550fa3c4add2679470d0d015cdfa205a Mon Sep 17 00:00:00 2001
From: Simon Ser <contact@emersion.fr>
Date: Tue, 18 Mar 2025 22:23:14 +0100
Subject: [PATCH 1/2] Define _POSIX_C_SOURCE globally

Other Sway projects have switched to this approach.
---
 log.c             | 1 -
 loop.c            | 1 -
 main.c            | 1 -
 meson.build       | 2 ++
 password-buffer.c | 1 -
 pool-buffer.c     | 1 -
 shadow.c          | 1 +
 7 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/log.c b/log.c
index cb4603966..dcb50909f 100644
--- a/log.c
+++ b/log.c
@@ -1,4 +1,3 @@
-#define _POSIX_C_SOURCE 199506L
 #include <errno.h>
 #include <stdarg.h>
 #include <stdio.h>
diff --git a/loop.c b/loop.c
index 8cbfaa6fc..7081b131a 100644
--- a/loop.c
+++ b/loop.c
@@ -1,4 +1,3 @@
-#define _POSIX_C_SOURCE 200809L
 #include <limits.h>
 #include <string.h>
 #include <stdbool.h>
diff --git a/main.c b/main.c
index 3a3a68f5e..479481737 100644
--- a/main.c
+++ b/main.c
@@ -1,4 +1,3 @@
-#define _POSIX_C_SOURCE 200809L
 #include <assert.h>
 #include <ctype.h>
 #include <errno.h>
diff --git a/meson.build b/meson.build
index f69ebfb8d..a530a2db6 100644
--- a/meson.build
+++ b/meson.build
@@ -11,6 +11,8 @@ project(
 	],
 )
 
+add_project_arguments('-D_POSIX_C_SOURCE=200809L', language: 'c')
+
 add_project_arguments(
 	[
 		'-Wno-unused-parameter',
diff --git a/password-buffer.c b/password-buffer.c
index 7b1e46582..1af992aea 100644
--- a/password-buffer.c
+++ b/password-buffer.c
@@ -1,4 +1,3 @@
-#define _POSIX_C_SOURCE 200809L
 #include "password-buffer.h"
 #include "log.h"
 #include "swaylock.h"
diff --git a/pool-buffer.c b/pool-buffer.c
index dfb4d0d4b..96271e11c 100644
--- a/pool-buffer.c
+++ b/pool-buffer.c
@@ -1,4 +1,3 @@
-#define _POSIX_C_SOURCE 200809L
 #include <assert.h>
 #include <cairo/cairo.h>
 #include <errno.h>
diff --git a/shadow.c b/shadow.c
index 3399d040d..83b0cc09e 100644
--- a/shadow.c
+++ b/shadow.c
@@ -1,3 +1,4 @@
+#undef _POSIX_C_SOURCE
 #define _XOPEN_SOURCE // for crypt
 #include <assert.h>
 #include <pwd.h>

From 0534a2cf6cdb74459d8ccf19a469ae002281d1fa Mon Sep 17 00:00:00 2001
From: Simon Ser <contact@emersion.fr>
Date: Tue, 18 Mar 2025 22:24:13 +0100
Subject: [PATCH 2/2] build: use cc.get_supported_arguments() for warnings

Let's not require the C compiler to support specific warnings,
especially if half the flags are used to turn off the warnings
anyways.
---
 meson.build | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/meson.build b/meson.build
index a530a2db6..cdbe6ff85 100644
--- a/meson.build
+++ b/meson.build
@@ -11,22 +11,18 @@ project(
 	],
 )
 
-add_project_arguments('-D_POSIX_C_SOURCE=200809L', language: 'c')
+cc = meson.get_compiler('c')
 
-add_project_arguments(
-	[
-		'-Wno-unused-parameter',
-		'-Wno-unused-result',
-		'-Wundef',
-		'-Wvla',
-	],
-	language: 'c',
-)
+add_project_arguments('-D_POSIX_C_SOURCE=200809L', language: 'c')
 
-cc = meson.get_compiler('c')
+add_project_arguments(cc.get_supported_arguments([
+	'-Wno-unused-parameter',
+	'-Wno-unused-result',
+	'-Wundef',
+	'-Wvla',
+]), language: 'c')
 
 is_freebsd = host_machine.system().startswith('freebsd')
-
 if is_freebsd
 	add_project_arguments('-D_C11_SOURCE', language: 'c')
 endif