Bug 892708 – dev-lang/vala: build failures

• Product: Gentoo Linux
• Status: RESOLVED FIXED

[Description Matt Jolly 2023-01-31 11:07:10 UTC]

Created attachment 849550 [details]
Failed Vala Build

While reviewing a PR in ::gentoo I noticed that the software was unable to build with modern Clang due to the following:

- [-Wint-conversion]
- [-Wincompatible-function-pointer-types]

I raised this issue with Vala upstream and was advised that it is likely a Vala bug and to raise an issue upstream:

https://gitlab.gnome.org/GNOME/vala/-/issues/1407

[Comment 1 Sam James 2023-02-12 01:03:37 UTC]

This may be fixed by the dev-lang/vala-0.56.4 bump today.

[Comment 2 Matt Jolly 2023-02-12 05:59:16 UTC]

Can confirm that both `net-im/dino` and `app-editors/zile` still fail to build.

Both fail with `error: incompatible function pointer types`

[Comment 3 cyrillic 2023-06-04 22:31:09 UTC]

This is what I am doing until the upstream bug gets fixed :

# diff -u /mnt/repos/{gentoo,fixes}/eclass/vala.eclass 
--- /mnt/repos/gentoo/eclass/vala.eclass	2023-03-26 08:27:04.386773000 -0400
+++ /mnt/repos/fixes/eclass/vala.eclass	2023-06-04 10:08:32.206192000 -0400
@@ -22,6 +22,8 @@
 if [[ -z ${_VALA_ECLASS} ]] ; then
 _VALA_ECLASS=1
 
+inherit flag-o-matic
+
 # @ECLASS_VARIABLE: VALA_MIN_API_VERSION
 # @DESCRIPTION:
 # Minimum vala API version (e.g. 0.56).
@@ -169,6 +171,9 @@
 	done
 	: "${PKG_CONFIG_PATH:="${EPREFIX}/usr/$(get_libdir)/pkgconfig:${EPREFIX}/usr/share/pkgconfig"}"
 	export PKG_CONFIG_PATH="${T}/pkgconfig:${PKG_CONFIG_PATH}"
+
+	# Workaround for https://gitlab.gnome.org/GNOME/vala/-/issues/1408
+	append-cflags -Wno-incompatible-function-pointer-types
 }
 
 # @FUNCTION: vala_src_prepare

[Comment 4 Sam James 2023-06-06 07:19:35 UTC]

(In reply to cyrillic from comment #3)
> This is what I am doing until the upstream bug gets fixed :
> 

Heh, I was putting off finding a way to get Vala to emit diff. flags or something, forgot we could do it in the eclass. This is good enough for now.

[Comment 5 Larry the Git Cow 2023-06-06 07:22:45 UTC]

The bug has been referenced in the following commit(s):

https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=7a834d5d13cdaea1cd1755c88ab35adc49f9a454

commit 7a834d5d13cdaea1cd1755c88ab35adc49f9a454
Author:     Sam James <[e-mail]>
AuthorDate: 2023-06-06 07:21:32 +0000
Commit:     Sam James <[e-mail]>
CommitDate: 2023-06-06 07:22:24 +0000

    vala.eclass: workaround Vala breakage with Clang 16
    
    Conditionally pass -Wno-incompatible-function-pointer-types for now in vala_setup
    until Vala itself is fixed.
    
    While this will affect other stuff in the same package, it's limited to when
    Vala is enabled, so it's better than before at least. Right now, the situation
    is both difficult for users & also blocks further testing.
    
    Thanks to cyrillic for the nudge.
    
    Bug: https://bugs.gentoo.org/892708
    Signed-off-by: Sam James <[e-mail]>

 eclass/vala.eclass | 6 ++++++
 1 file changed, 6 insertions(+)

[Comment 6 Larry the Git Cow 2023-12-04 07:32:50 UTC]

The bug has been referenced in the following commit(s):

https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=5fe21d4ec04889a3019dea71ffd69b31825dc394

commit 5fe21d4ec04889a3019dea71ffd69b31825dc394
Author:     Sam James <[e-mail]>
AuthorDate: 2023-12-04 07:12:36 +0000
Commit:     Sam James <[e-mail]>
CommitDate: 2023-12-04 07:32:13 +0000

    vala.eclass: adapt modern c workaround for gcc
    
    GCC doesn't have -Wincompatible-function-pointer-types, just -Wincompatible-pointer-types,
    and it makes the latter fatal in GCC 14.
    
    Just adapt the workaround to use that for now until Vala is fixed properly upstream.
    
    Bug: https://bugs.gentoo.org/892708
    Signed-off-by: Sam James <[e-mail]>

 eclass/vala.eclass | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

[Comment 7 Christopher Fore 2023-12-11 15:54:15 UTC]

Created attachment 878669 [details]
build.log using gcc 14

Fails on GCC 14 as well

valacodecontext.c:2669:33: error: assignment to 'gchar **' {aka 'char **'} from incompatible pointer type 'const gchar * const*' {aka 'const char * const*'} [-Wincompatible-pointer-types]
 2669 |                 _tmp4_ = _tmp3_ = g_get_system_data_dirs ();
      |                                 ^
valacodecontext.c:2700:33: error: assignment to 'gchar **' {aka 'char **'} from incompatible pointer type 'const gchar * const*' {aka 'const char * const*'} [-Wincompatible-pointer-types]
 2700 |                 _tmp9_ = _tmp8_ = g_get_system_data_dirs ();
      |                                 ^

$ gcc-config -l
...
 [3] x86_64-pc-linux-gnu-13
 [4] x86_64-pc-linux-gnu-14 *

[Comment 8 Christopher Fore 2023-12-11 15:54:57 UTC]

*** Bug 919710 has been marked as a duplicate of this bug. ***

[Comment 9 Sam James 2024-05-06 07:07:13 UTC]

I think we're good now with 0.56.15. Any further issues may either be an issue in the application, or a distinct issue with Vala, but the primary thing is fixed.