While detecting a presence of a function via 'cc.links()' gives desired result (i.e. detects whether function is present), it also produces a warning on systems where the function is not present (into meson-log.txt), e.g.:
qemu.git/build/meson-private/tmph74x3p38/testfile.c:2:34: \ warning: implicit declaration of function 'malloc_trim' [-Wimplicit-function-declaration] We can check whether given function exists via 'cc.has_function()' or whether STATX_* macros exist via 'cc.has_header_symbol()'. Resolves: https://bugs.gentoo.org/898810 Signed-off-by: Michal Privoznik <mpriv...@redhat.com> --- v2 of: https://lists.gnu.org/archive/html/qemu-devel/2023-05/msg07138.html diff to v1: - Drop cc.links() as it's redundant meson.build | 26 +++++--------------------- 1 file changed, 5 insertions(+), 21 deletions(-) diff --git a/meson.build b/meson.build index 2d48aa1e2e..21061b19d4 100644 --- a/meson.build +++ b/meson.build @@ -1797,8 +1797,7 @@ malloc = [] if get_option('malloc') == 'system' has_malloc_trim = \ get_option('malloc_trim').allowed() and \ - cc.links('''#include <malloc.h> - int main(void) { malloc_trim(0); return 0; }''') + cc.has_function('malloc_trim', prefix: '#include <malloc.h>') else has_malloc_trim = false malloc = cc.find_library(get_option('malloc'), required: true) @@ -1811,34 +1810,19 @@ if not has_malloc_trim and get_option('malloc_trim').enabled() endif endif -# Check whether the glibc provides statx() - gnu_source_prefix = ''' #ifndef _GNU_SOURCE #define _GNU_SOURCE #endif ''' -statx_test = gnu_source_prefix + ''' - #include <sys/stat.h> - int main(void) { - struct statx statxbuf; - statx(0, "", 0, STATX_BASIC_STATS, &statxbuf); - return 0; - }''' -has_statx = cc.links(statx_test) +# Check whether the glibc provides STATX_BASIC_STATS + +has_statx = cc.has_header_symbol('sys/stat.h', 'STATX_BASIC_STATS', prefix: gnu_source_prefix) # Check whether statx() provides mount ID information -statx_mnt_id_test = gnu_source_prefix + ''' - #include <sys/stat.h> - int main(void) { - struct statx statxbuf; - statx(0, "", 0, STATX_BASIC_STATS | STATX_MNT_ID, &statxbuf); - return statxbuf.stx_mnt_id; - }''' - -has_statx_mnt_id = cc.links(statx_mnt_id_test) +has_statx_mnt_id = cc.has_header_symbol('sys/stat.h', 'STATX_MNT_ID', prefix: gnu_source_prefix) have_vhost_user_blk_server = get_option('vhost_user_blk_server') \ .require(targetos == 'linux', -- 2.39.3
