gallium: fix reference counting functions to be strict-aliasing compliant

Historically, parts of mesa code are not strict-aliasing safe, hence
-fno-strict-aliasing is needed to compile (this got forgotten for scons
builds for gallium, which indeed not only caused compiler warnings but also
unexplicable crashes in non-debug builds). However, we should try to eliminate
code not complying with strict-aliasing code at least for gallium.
Hence change pipe_reference functions to make them strict-aliasing compliant.
This adds a bit more complexity (especially for derived classes) but is the
right thing to do, and it does in fact fix a segfault.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/gallium/drivers/svga/svga_screen_texture.h b/src/gallium/drivers/svga/svga_screen_texture.h
index 1cc4063e65..727f2c51d2 100644
--- a/src/gallium/drivers/svga/svga_screen_texture.h
+++ b/src/gallium/drivers/svga/svga_screen_texture.h
@@ -164,8 +164,9 @@ svga_sampler_view_reference(struct svga_sampler_view **ptr, struct svga_sampler_
 {
    struct svga_sampler_view *old = *ptr;
 
-   if (pipe_reference((struct pipe_reference **)ptr, &v->reference))
+   if (pipe_reference(&(*ptr)->reference, &v->reference))
       svga_destroy_sampler_view_priv(old);
+   *ptr = v;
 }
 
 extern void