build-sys: Detect whether struct statx is defined in sys/stat.h

Starting with glibc 2.27.9000-36.fc29, include file sys/stat.h will have a
definition for struct statx, in which case include file linux/stat.h should be
avoided, in order to prevent a duplicate definition.

    In file included from ../src/basic/missing.h:18,
		     from ../src/basic/util.h:28,
		     from ../src/basic/hashmap.h:10,
		     from ../src/shared/bus-util.h:12,
		     from ../src/libsystemd/sd-bus/bus-creds.c:11:
    /usr/include/linux/stat.h:99:8: error: redefinition of ‘struct statx’
     struct statx {
	    ^~~~~
    In file included from /usr/include/sys/stat.h:446,
		     from ../src/basic/util.h:19,
		     from ../src/basic/hashmap.h:10,
		     from ../src/shared/bus-util.h:12,
		     from ../src/libsystemd/sd-bus/bus-creds.c:11:
    /usr/include/bits/statx.h:36:8: note: originally defined here
     struct statx
	    ^~~~~

Extend our meson.build to look for struct statx when only sys/stat.h is
included and, in that case, do not include linux/stat.h anymore.

Tested that systemd builds correctly when using a glibc version that includes a
definition for struct statx.

glibc Fedora RPM update:
https://src.fedoraproject.org/rpms/glibc/c/28cb5d31fc1e5887912283c889689c47076278ae

glibc upstream commit:
https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=fd70af45528d59a00eb3190ef6706cb299488fcd

diff --git a/meson.build b/meson.build
index dd904c7148714523e52bf631aee6eb4f10eccf99..68423bdfa5ef4ead8099d973cf823a0ab8e76198 100644 (file)
--- a/meson.build
+++ b/meson.build
@@ -425,6 +425,7 @@ decl_headers = '''
 #include <sys/stat.h>
 '''
 # FIXME: key_serial_t is only defined in keyutils.h, this is bound to fail
+# FIXME: these should use -D_GNU_SOURCE, since that is defined at build time
 
 foreach decl : ['char16_t',
                 'char32_t',
@@ -439,6 +440,10 @@ foreach decl : ['char16_t',
         conf.set10('HAVE_' + decl.underscorify().to_upper(), have)
 endforeach
 
+conf.set10('HAVE_STRUCT_STATX_IN_SYS_STAT_H', cc.sizeof('struct statx', prefix : '''
+#include <sys/stat.h>
+''', args : '-D_GNU_SOURCE') > 0)
+
 foreach decl : [['IFLA_INET6_ADDR_GEN_MODE',         'linux/if_link.h'],
                 ['IN6_ADDR_GEN_MODE_STABLE_PRIVACY', 'linux/if_link.h'],
                 ['IFLA_VRF_TABLE',                   'linux/if_link.h'],

diff --git a/src/basic/missing.h b/src/basic/missing.h
index 71a07d05747454dfbd5bfb6224c707ed67a115ac..14ad3d49140fa1bd348fbd918fdbfdbfad214fe9 100644 (file)
--- a/src/basic/missing.h
+++ b/src/basic/missing.h
@@ -15,7 +15,6 @@
 #include <linux/neighbour.h>
 #include <linux/oom.h>
 #include <linux/rtnetlink.h>
-#include <linux/stat.h>
 #include <net/ethernet.h>
 #include <stdlib.h>
 #include <sys/resource.h>
@@ -25,6 +24,10 @@
 #include <uchar.h>
 #include <unistd.h>
 
+#if !HAVE_STRUCT_STATX_IN_SYS_STAT_H
+#include <linux/stat.h>
+#endif
+
 #if HAVE_AUDIT
 #include <libaudit.h>
 #endif

diff --git a/src/basic/xattr-util.c b/src/basic/xattr-util.c
index c5c55ea8461a7fc76f25bfb5630f3b5946535405..0ee0979837cdfb6b29bdb4d20112a81abff9c437 100644 (file)
--- a/src/basic/xattr-util.c
+++ b/src/basic/xattr-util.c
@@ -2,7 +2,6 @@
 
 #include <errno.h>
 #include <fcntl.h>
-#include <linux/stat.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>