[FFmpeg-devel] [PATCH] Fix missing used attribute for inline assembly variables

[Thomas Köppe]

Variables used in inline assembly need to be marked with attribute((used)).
Static constants already were, via the define of DECLARE_ASM_CONST.
But DECLARE_ALIGNED does not add this attribute, and some of the variables
defined with it are const only used in inline assembly, and therefore
appeared dead.
---
 libavcodec/cabac.c | 2 +-
 libavutil/mem.h    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavcodec/cabac.c b/libavcodec/cabac.c
index dd2b057c6d..7321b48901 100644
--- a/libavcodec/cabac.c
+++ b/libavcodec/cabac.c
@@ -32,7 +32,7 @@
 #include "cabac.h"
 #include "cabac_functions.h"
 
-const uint8_t ff_h264_cabac_tables[512 + 4*2*64 + 4*64 + 63] = {
+DECLARE_ALIGNED(1, const uint8_t, ff_h264_cabac_tables)[512 + 4*2*64 + 4*64 + 63] = {
     9,8,7,7,6,6,6,6,5,5,5,5,5,5,5,5,
     4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
     3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
diff --git a/libavutil/mem.h b/libavutil/mem.h
index 527cd03191..c4ee11af58 100644
--- a/libavutil/mem.h
+++ b/libavutil/mem.h
@@ -101,7 +101,7 @@
     #define DECLARE_ALIGNED(n,t,v)      t __attribute__ ((aligned (FFMIN(n, 16)))) v
     #define DECLARE_ASM_CONST(n,t,v)    static const t av_used __attribute__ ((aligned (FFMIN(n, 16)))) v
 #elif defined(__GNUC__) || defined(__clang__)
-    #define DECLARE_ALIGNED(n,t,v)      t __attribute__ ((aligned (n))) v
+    #define DECLARE_ALIGNED(n,t,v)      t av_used __attribute__ ((aligned (n))) v
     #define DECLARE_ASM_CONST(n,t,v)    static const t av_used __attribute__ ((aligned (n))) v
 #elif defined(_MSC_VER)
     #define DECLARE_ALIGNED(n,t,v)      __declspec(align(n)) t v
-- 
2.15.0.rc2.357.g7e34df9404-goog