meson: unbreak sysctl.h detection on BSDs

Code:
 #include <sys/sysctl.h>
Compiler stdout:

Compiler stderr:
 In file included from testfile.c:1:
/usr/include/sys/sysctl.h:1184:40: error: unknown type name 'size_t'
int     sysctl(const int *, u_int, void *, size_t *, const void *, size_t);
                                           ^
/usr/include/sys/sysctl.h:1185:40: error: unknown type name 'size_t'
int     sysctlbyname(const char *, void *, size_t *, const void *, size_t);
                                           ^
/usr/include/sys/sysctl.h:1186:42: error: unknown type name 'size_t'
int     sysctlnametomib(const char *, int *, size_t *);
                                             ^
3 errors generated.

Checking if "sys/sysctl.h" compiles: NO

<https://gitlab.freedesktop.org/mesa/drm/-/commit/1f8ada802391>
<https://gitlab.freedesktop.org/mesa/drm/-/commit/4083e8f2c659>

Reviewed-by: Niclas Zeising <zeising@daemonic.se>
Reviewed-by: Eric Engestrom <eric@engestrom.ch>
Cc: mesa-stable
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5462>

diff --git a/meson.build b/meson.build
index 1932410fcf7d3a0b10d198dbef9513be1995edf8..f14af82ace738920afb7a0ecf7628420025aa83a 100644 (file)
--- a/meson.build
+++ b/meson.build
@@ -1202,7 +1202,14 @@ if (cc.has_header_symbol('sys/mkdev.h', 'major') and
   pre_args += '-DMAJOR_IN_MKDEV'
 endif
 
-foreach h : ['xlocale.h', 'sys/sysctl.h', 'linux/futex.h', 'endian.h', 'dlfcn.h', 'execinfo.h', 'sys/shm.h', 'cet.h']
+if not ['linux'].contains(host_machine.system())
+  # Deprecated on Linux and requires <sys/types.h> on FreeBSD and OpenBSD
+  if cc.check_header('sys/sysctl.h', prefix : '#include <sys/types.h>')
+    pre_args += '-DHAVE_SYS_SYSCTL_H'
+  endif
+endif
+
+foreach h : ['xlocale.h', 'linux/futex.h', 'endian.h', 'dlfcn.h', 'execinfo.h', 'sys/shm.h', 'cet.h']
   if cc.check_header(h)
     pre_args += '-DHAVE_@0@'.format(h.to_upper().underscorify())
   endif