[PATCH] redis: fix build of the bundled xxHash with -Og

redis 8.8 started bundling a post-0.8.3 xxHash snapshot in deps/xxhash,
which is built and linked into redis-server. Its XXH3 accumulate and
scramble routines are marked always_inline but are only ever reached
through function pointers, so the compiler has to resolve the indirect
call before it can honour the attribute.

xxHash drops those inline hints on its own when __NO_INLINE__ is
defined, which covers -O0 and -fno-inline, but nothing covers -Og.
Recent GCC no longer resolves the indirect calls at that optimisation
level, so every build with DEBUG_BUILD = "1" fails:

  xxhash.h:5476:1: error: inlining failed in call to 'always_inline'
  'XXH3_scrambleAcc_neon': function not considered for inlining
  make[2]: *** [Makefile:108: xxhash] Error 2
  ld: cannot find ../deps/xxhash/libxxhash.a: No such file or directory

Upstream xxHash closed this as not fixable in code (Cyan4973/xxHash#943)
and instead documents XXH_NO_INLINE_HINTS as the supported way to
compile with -Og. Define it when -Og is the selected optimisation,
leaving regular builds untouched so xxHash keeps its inline hints there.

AI-Generated: Uses Claude Code
Signed-off-by: Ricardo Salveti <[email protected]>
---
 meta-oe/recipes-extended/redis/redis_8.10.0.bb | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/meta-oe/recipes-extended/redis/redis_8.10.0.bb b/meta-oe/recipes-extended/redis/redis_8.10.0.bb
index 6176dc45be..3edaa9155c 100644
--- a/meta-oe/recipes-extended/redis/redis_8.10.0.bb
+++ b/meta-oe/recipes-extended/redis/redis_8.10.0.bb
@@ -43,6 +43,14 @@ EXTRA_OEMAKE += "${PACKAGECONFIG_CONFARGS}"
 
 TARGET_LDFLAGS:append = " ${DEBUG_PREFIX_MAP}"
 
+# The bundled xxHash marks its XXH3 vector paths always_inline but only reaches
+# them through function pointers. It drops the inline hints on its own when
+# __NO_INLINE__ is defined (-O0, -fno-inline) but never for -Og, and recent GCC
+# no longer resolves those indirect calls at -Og, so deps/xxhash fails to
+# build. Upstream xxHash closed this as not fixable in code and documents
+# XXH_NO_INLINE_HINTS as the supported way to compile with -Og.
+CFLAGS:append = "${@' -DXXH_NO_INLINE_HINTS' if '-Og' in (d.getVar('SELECTED_OPTIMIZATION') or '') else ''}"
+
 do_compile:prepend() {
     oe_runmake -C deps hdr_histogram fpconv hiredis lua linenoise
 }
-- 
2.43.0