On older Solaris releases, we didn't get a protype for madvise, and so
util/osdep.c provides its own prototype. Some time between the public
Solaris 11.4 release and Solaris 11.4.42 CBE, we started getting an
madvise prototype that looks like this:
extern int madvise(void *, size_t, int);
which conflicts with the prototype in util/osdeps.c. Instead of always
declaring this prototype, check if we're missing the madvise()
prototype, and only declare it ourselves if the prototype is missing.
The 'missing_madvise_proto' meson check contains an obviously wrong
prototype for madvise. So if that code compiles and links, we must be
missing the actual prototype for madvise.
Signed-off-by: Andrew Deason <adea...@sinenomine.net>
---
To be clear, I'm okay with removing the prototype workaround
unconditionally; I'm just not sure if there's enough consensus on doing
that.
The "missing prototype" check is based on getting a compiler error on a
conflicting prototype, since this just seems more precise and certain
than getting an error from a missing prototype (needs
-Werror=missing-prototypes or -Werror). But I can do it the other way
around if needed.
Changes since v1:
- madvise prototype check changed to not be platforms-specific, and turned into
CONFIG_MADVISE_MISSING_PROTOTYPE.
meson.build | 17 +++++++++++++++--
util/osdep.c | 3 +++
2 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/meson.build b/meson.build
index 2d6601467f..ff5fce693e 100644
--- a/meson.build
+++ b/meson.build
@@ -1705,25 +1705,38 @@ config_host_data.set('CONFIG_EVENTFD', cc.links('''
int main(void) { return eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC); }'''))
config_host_data.set('CONFIG_FDATASYNC', cc.links(gnu_source_prefix + '''
#include <unistd.h>
int main(void) {
#if defined(_POSIX_SYNCHRONIZED_IO) && _POSIX_SYNCHRONIZED_IO > 0
return fdatasync(0);
#else
#error Not supported
#endif
}'''))
-config_host_data.set('CONFIG_MADVISE', cc.links(gnu_source_prefix + '''
+
+has_madvise = cc.links(gnu_source_prefix + '''
#include <sys/types.h>
#include <sys/mman.h>
#include <stddef.h>
- int main(void) { return madvise(NULL, 0, MADV_DONTNEED); }'''))
+ int main(void) { return madvise(NULL, 0, MADV_DONTNEED); }''')
+missing_madvise_proto = false
+if has_madvise
+ missing_madvise_proto = cc.links(gnu_source_prefix + '''
+ #include <sys/types.h>
+ #include <sys/mman.h>
+ #include <stddef.h>
+ extern int madvise(int);
+ int main(void) { return madvise(0); }''')
+endif
+config_host_data.set('CONFIG_MADVISE', has_madvise)
+config_host_data.set('CONFIG_MADVISE_MISSING_PROTOTYPE', missing_madvise_proto)
+
config_host_data.set('CONFIG_MEMFD', cc.links(gnu_source_prefix + '''
#include <sys/mman.h>
int main(void) { return memfd_create("foo", MFD_ALLOW_SEALING); }'''))
config_host_data.set('CONFIG_OPEN_BY_HANDLE', cc.links(gnu_source_prefix + '''
#include <fcntl.h>
#if !defined(AT_EMPTY_PATH)
# error missing definition
#else
int main(void) { struct file_handle fh; return open_by_handle_at(0, &fh, 0);
}
#endif'''))
diff --git a/util/osdep.c b/util/osdep.c
index 7c4deda6fe..560ce9111a 100644
--- a/util/osdep.c
+++ b/util/osdep.c
@@ -21,20 +21,23 @@
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
/* Needed early for CONFIG_BSD etc. */
#ifdef CONFIG_SOLARIS
#include <sys/statvfs.h>
+#endif
+
+#ifdef HAVE_MADVISE_MISSING_PROTOTYPE
/* See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=7156) for
discussion about Solaris header problems */
extern int madvise(char *, size_t, int);
#endif
#include "qemu-common.h"
#include "qemu/cutils.h"
#include "qemu/sockets.h"
#include "qemu/error-report.h"
#include "qemu/madvise.h"
--
2.11.0
