[PATCH for-10.1] meson: Fix brlapi compile test for Windows builds

[PATCH for-10.1] meson: Fix brlapi compile test for Windows builds

[Stefan Weil via]

brlapi__openConnection returns a brlapi_fileDescriptor which is a pointer
for Windows builds.

The test for brlapi fails with cross builds on Debian trixie
(x86_64-w64-mingw32-gcc (GCC) 14-win32):

testfile.c:4:30: error: returning 'brlapi_fileDescriptor' {aka 'void *'} from a function with return type 'int' makes integer from pointer without a cast [-Wint-conversion]
    4 |      int main(void) { return brlapi__openConnection (NULL, NULL, NULL); }
      |                              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-----------
../../../meson.build:1607: WARNING: could not link brlapi, disabling

Signed-off-by: Stefan Weil <sw@weilnetz.de>
---

I think that this patch is trivial because it does not change
anything for Linux.

Note that this patch only fixes the configure test and allows builds
with the Braille API for Windows.

A similar change can be applied to chardev/baum.c and will be sent
separately because it is not required for 10.1.

Note that for 64 bit Windows there is an issue because brlapi_fileDescriptor
is a 64 bit pointer while QEMU assumes int for file descriptors. But the
good news is that the resulting code seems to work nevertheless – at least
the people who asked me for Braille support on Windows are satisfied as
far as I know.

Regards,
Stefan W.


 meson.build | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/meson.build b/meson.build
index e53cd5b413..d6abe1917e 100644
--- a/meson.build
+++ b/meson.build
@@ -1586,9 +1586,11 @@ if not get_option('brlapi').auto() or have_system
   brlapi = cc.find_library('brlapi', has_headers: ['brlapi.h'],
                          required: get_option('brlapi'))
   if brlapi.found() and not cc.links('''
-     #include <brlapi.h>
-     #include <stddef.h>
-     int main(void) { return brlapi__openConnection (NULL, NULL, NULL); }''', dependencies: brlapi)
+    #include <brlapi.h>
+    #include <stddef.h>
+    int main(void) {
+      return brlapi__openConnection(NULL, NULL, NULL) == BRLAPI_INVALID_FILE_DESCRIPTOR;
+    }''', dependencies: brlapi)
     brlapi = not_found
     if get_option('brlapi').enabled()
       error('could not link brlapi')
-- 
2.47.2

Re: [PATCH for-10.1] meson: Fix brlapi compile test for Windows builds

[Pierrick Bouvier]

On 8/6/25 1:45 PM, Stefan Weil via wrote:
> brlapi__openConnection returns a brlapi_fileDescriptor which is a pointer
> for Windows builds.
> 
> The test for brlapi fails with cross builds on Debian trixie
> (x86_64-w64-mingw32-gcc (GCC) 14-win32):
> 
> testfile.c:4:30: error: returning 'brlapi_fileDescriptor' {aka 'void *'} from a function with return type 'int' makes integer from pointer without a cast [-Wint-conversion]
>      4 |      int main(void) { return brlapi__openConnection (NULL, NULL, NULL); }
>        |                              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> -----------
> ../../../meson.build:1607: WARNING: could not link brlapi, disabling
> 
> Signed-off-by: Stefan Weil <sw@weilnetz.de>
> ---
> 
> I think that this patch is trivial because it does not change
> anything for Linux.
> 
> Note that this patch only fixes the configure test and allows builds
> with the Braille API for Windows.
> 
> A similar change can be applied to chardev/baum.c and will be sent
> separately because it is not required for 10.1.
> 
> Note that for 64 bit Windows there is an issue because brlapi_fileDescriptor
> is a 64 bit pointer while QEMU assumes int for file descriptors. But the
> good news is that the resulting code seems to work nevertheless – at least
> the people who asked me for Braille support on Windows are satisfied as
> far as I know.
> 
> Regards,
> Stefan W.
> 
> 
>   meson.build | 8 +++++---
>   1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/meson.build b/meson.build
> index e53cd5b413..d6abe1917e 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -1586,9 +1586,11 @@ if not get_option('brlapi').auto() or have_system
>     brlapi = cc.find_library('brlapi', has_headers: ['brlapi.h'],
>                            required: get_option('brlapi'))
>     if brlapi.found() and not cc.links('''
> -     #include <brlapi.h>
> -     #include <stddef.h>
> -     int main(void) { return brlapi__openConnection (NULL, NULL, NULL); }''', dependencies: brlapi)
> +    #include <brlapi.h>
> +    #include <stddef.h>
> +    int main(void) {
> +      return brlapi__openConnection(NULL, NULL, NULL) == BRLAPI_INVALID_FILE_DESCRIPTOR;
> +    }''', dependencies: brlapi)
>       brlapi = not_found
>       if get_option('brlapi').enabled()
>         error('could not link brlapi')

Looks good,
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>

Re: [PATCH for-10.1] meson: Fix brlapi compile test for Windows builds

[Thomas Huth]

On 06/08/2025 22.45, Stefan Weil via wrote:
> brlapi__openConnection returns a brlapi_fileDescriptor which is a pointer
> for Windows builds.
> 
> The test for brlapi fails with cross builds on Debian trixie
> (x86_64-w64-mingw32-gcc (GCC) 14-win32):
> 
> testfile.c:4:30: error: returning 'brlapi_fileDescriptor' {aka 'void *'} from a function with return type 'int' makes integer from pointer without a cast [-Wint-conversion]
>      4 |      int main(void) { return brlapi__openConnection (NULL, NULL, NULL); }
>        |                              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> -----------
> ../../../meson.build:1607: WARNING: could not link brlapi, disabling
> 
> Signed-off-by: Stefan Weil <sw@weilnetz.de>
> ---
> 
> I think that this patch is trivial because it does not change
> anything for Linux.
> 
> Note that this patch only fixes the configure test and allows builds
> with the Braille API for Windows.
> 
> A similar change can be applied to chardev/baum.c and will be sent
> separately because it is not required for 10.1.
> 
> Note that for 64 bit Windows there is an issue because brlapi_fileDescriptor
> is a 64 bit pointer while QEMU assumes int for file descriptors. But the
> good news is that the resulting code seems to work nevertheless – at least
> the people who asked me for Braille support on Windows are satisfied as
> far as I know.
> 
> Regards,
> Stefan W.
> 
> 
>   meson.build | 8 +++++---
>   1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/meson.build b/meson.build
> index e53cd5b413..d6abe1917e 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -1586,9 +1586,11 @@ if not get_option('brlapi').auto() or have_system
>     brlapi = cc.find_library('brlapi', has_headers: ['brlapi.h'],
>                            required: get_option('brlapi'))
>     if brlapi.found() and not cc.links('''
> -     #include <brlapi.h>
> -     #include <stddef.h>
> -     int main(void) { return brlapi__openConnection (NULL, NULL, NULL); }''', dependencies: brlapi)
> +    #include <brlapi.h>
> +    #include <stddef.h>
> +    int main(void) {
> +      return brlapi__openConnection(NULL, NULL, NULL) == BRLAPI_INVALID_FILE_DESCRIPTOR;
> +    }''', dependencies: brlapi)
>       brlapi = not_found
>       if get_option('brlapi').enabled()
>         error('could not link brlapi')

Reviewed-by: Thomas Huth <thuth@redhat.com>