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/auxiliary/pipebuffer/pb_buffer.h b/src/gallium/auxiliary/pipebuffer/pb_buffer.h
index 4ef372233f0..eb7e84be848 100644
--- a/src/gallium/auxiliary/pipebuffer/pb_buffer.h
+++ b/src/gallium/auxiliary/pipebuffer/pb_buffer.h
@@ -237,8 +237,9 @@ pb_reference(struct pb_buffer **dst,
 {
    struct pb_buffer *old = *dst;
 
-   if (pipe_reference((struct pipe_reference**)dst, &src->base.reference))
+   if (pipe_reference(&(*dst)->base.reference, &src->base.reference))
       pb_destroy( old );
+   *dst = src;
 }