On Thu Dec 19, 2024 at 4:21 AM AEST, Philippe Mathieu-Daudé wrote:
> When running Clang static analyzer on macOS I'm getting:
>
> include/qemu/osdep.h:634:8: error: redefinition of 'iovec'
> 634 | struct iovec {
> | ^
>
> /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/sys/_types/_iovec_t.h:31:8:
> note: previous definition is here
> 31 | struct iovec {
> | ^
> 1 error generated.
>
> Looking at meson-logs.txt, the analyzer enables -Wunused-value
> making meson generated code to fail:
>
> Code:
> #include <sys/uio.h>
> void bar(void) {
> sizeof(struct iovec);
> }
> -----------
> stderr:
> meson-private/tmpe8_1b_00/testfile.c:3:13: error: expression result
> unused [-Werror,-Wunused-value]
> 3 | sizeof(struct iovec);
> | ^~~~~~~~~~~~~~~~~~~~
> 1 error generated.
> -----------
> Checking for type "struct iovec" : NO
>
> Code:
> #include <utmpx.h>
> void bar(void) {
> sizeof(struct utmpx);
> }
> -----------
> stderr:
> meson-private/tmp3n0u490p/testfile.c:3:13: error: expression result
> unused [-Werror,-Wunused-value]
> 3 | sizeof(struct utmpx);
> | ^~~~~~~~~~~~~~~~~~~~
> 1 error generated.
> -----------
> Checking for type "struct utmpx" : NO
>
> Code:
>
> #include <getopt.h>
> int main(void) {
> /* If it's not defined as a macro, try to use as a symbol */
> #ifndef optreset
> optreset;
> #endif
> return 0;
> }
> -----------
> stderr:
> meson-private/tmp1rzob_os/testfile.c:6:17: error: expression result
> unused [-Werror,-Wunused-value]
> 6 | optreset;
> | ^~~~~~~~
> 1 error generated.
> -----------
> Header "getopt.h" has symbol "optreset" : NO
>
> Code:
>
> #include <vmnet/vmnet.h>
> int main(void) {
> /* If it's not defined as a macro, try to use as a symbol */
> #ifndef VMNET_BRIDGED_MODE
> VMNET_BRIDGED_MODE;
> #endif
> return 0;
> }
> -----------
> stderr:
> meson-private/tmpl9jgsxpt/testfile.c:6:17: error: expression result
> unused [-Werror,-Wunused-value]
> 6 | VMNET_BRIDGED_MODE;
> | ^~~~~~~~~~~~~~~~~~
> 1 error generated.
> -----------
> Header "vmnet/vmnet.h" has symbol "VMNET_BRIDGED_MODE" with dependency
> appleframeworks: NO
> ../meson.build:1174: WARNING: vmnet.framework API is outdated, disabling
>
> Fix by explicitly disabling -Wunused-value from these meson checks.
>
> Signed-off-by: Philippe Mathieu-Daudé <phi...@linaro.org>
> ---
> RFC: Probably meson should do that in has_header_symbol() / has_type()?
I don't know about the build system to answer this, but should we
instead disable -Werror on these tests to be a bit more future-proof?
Compilers often add new warnings or catch more cases of existing
warnings.
Alternative would be to keep -Werror but fail the build if a test
throws a warning, but that seems like a lot more work for little
benefit...
Thanks,
Nick
> ---
> meson.build | 11 +++++++----
> 1 file changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/meson.build b/meson.build
> index 85f74854735..9d93dcd95d7 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -1189,7 +1189,8 @@ cocoa = dependency('appleframeworks',
> vmnet = dependency('appleframeworks', modules: 'vmnet', required:
> get_option('vmnet'))
> if vmnet.found() and not cc.has_header_symbol('vmnet/vmnet.h',
> 'VMNET_BRIDGED_MODE',
> - dependencies: vmnet)
> + dependencies: vmnet,
> + args: '-Wno-unused-value')
> vmnet = not_found
> if get_option('vmnet').enabled()
> error('vmnet.framework API is outdated')
> @@ -2713,7 +2714,7 @@ config_host_data.set('CONFIG_RTNETLINK',
> config_host_data.set('CONFIG_SYSMACROS',
> cc.has_header_symbol('sys/sysmacros.h', 'makedev'))
> config_host_data.set('HAVE_OPTRESET',
> - cc.has_header_symbol('getopt.h', 'optreset'))
> + cc.has_header_symbol('getopt.h', 'optreset', args:
> '-Wno-unused-value'))
> config_host_data.set('HAVE_IPPROTO_MPTCP',
> cc.has_header_symbol('netinet/in.h', 'IPPROTO_MPTCP'))
>
> @@ -2731,10 +2732,12 @@ config_host_data.set('HAVE_BLK_ZONE_REP_CAPACITY',
> # has_type
> config_host_data.set('CONFIG_IOVEC',
> cc.has_type('struct iovec',
> - prefix: '#include <sys/uio.h>'))
> + prefix: '#include <sys/uio.h>',
> + args: '-Wno-unused-value'))
> config_host_data.set('HAVE_UTMPX',
> cc.has_type('struct utmpx',
> - prefix: '#include <utmpx.h>'))
> + prefix: '#include <utmpx.h>',
> + args: '-Wno-unused-value'))
>
> config_host_data.set('CONFIG_EVENTFD', cc.links('''
> #include <sys/eventfd.h>
