[PATCH] Add compatibility wrappers for functions moved from lavf to lavc

[Mans Rullgard]

When symbol versioning is enabled, moving symbols from one library to
another breaks binary compatibility.  This adds wrappers with the old
version tag for the av_*packet functions recently moved to lavc.
---
 configure            |   16 +++++++++++++++-
 libavformat/utils.c  |   32 +++++++++++++++++++++++++++++++-
 libavutil/internal.h |   11 +++++++++++
 3 files changed, 57 insertions(+), 2 deletions(-)

diff --git a/configure b/configure
index 2083217..7016e5b 100755
--- a/configure
+++ b/configure
@@ -1084,6 +1084,9 @@ HAVE_LIST="
     struct_sockaddr_in6
     struct_sockaddr_sa_len
     struct_sockaddr_storage
+    symver
+    symver_gnu_asm
+    symver_asm_label
     sys_mman_h
     sys_resource_h
     sys_select_h
@@ -1198,6 +1201,8 @@ fast_unaligned_if_any="armv6 ppc x86"
 need_memalign="altivec neon sse"
 inline_asm_deps="!tms470"
 
+symver_if_any="symver_asm_label symver_gnu_asm"
+
 # subsystems
 mdct_select="fft"
 rdft_select="fft"
@@ -2714,8 +2719,17 @@ check_ldflags '-Wl,-rpath-link,\$(BUILD_ROOT)/libpostproc -Wl,-rpath-link,\$(BUI
 check_ldflags -Wl,-Bsymbolic
 
 echo "X{};" > $TMPV
-test_ldflags -Wl,--version-script,$TMPV &&
+if test_ldflags -Wl,--version-script,$TMPV; then
     append SHFLAGS '-Wl,--version-script,\$(SUBDIR)lib\$(NAME).ver'
+    check_cc <<EOF && enable symver_asm_label
+void ff_foo(void) __asm__ ("av_foo at VERSION");
+void ff_foo(void) {}
+EOF
+    check_cc <<EOF && enable symver_gnu_asm
+__asm__(".symver ff_foo,av_foo at VERSION");
+void ff_foo(void) {}
+EOF
+fi
 
 if enabled small; then
     add_cflags $size_cflags
diff --git a/libavformat/utils.c b/libavformat/utils.c
index 6365f3e..9faa566 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -283,8 +283,38 @@ AVInputFormat *av_find_input_format(const char *short_name)
     return NULL;
 }
 
-/* memory handling */
+#if LIBAVFORMAT_VERSION_MAJOR < 53 && CONFIG_SHARED && HAVE_SYMVER
+FF_SYMVER(void, av_destruct_packet_nofree, (AVPacket *pkt), "LIBAVFORMAT_52")
+{
+    av_destruct_packet_nofree(pkt);
+}
+
+FF_SYMVER(void, av_destruct_packet, (AVPacket *pkt), "LIBAVFORMAT_52")
+{
+    av_destruct_packet(pkt);
+}
+
+FF_SYMVER(int, av_new_packet, (AVPacket *pkt, int size), "LIBAVFORMAT_52")
+{
+    return av_new_packet(pkt, size);
+}
+
+FF_SYMVER(int, av_dup_packet, (AVPacket *pkt), "LIBAVFORMAT_52")
+{
+    return av_dup_packet(pkt);
+}
+
+FF_SYMVER(void, av_free_packet, (AVPacket *pkt), "LIBAVFORMAT_52")
+{
+    av_free_packet(pkt);
+}
 
+FF_SYMVER(void, av_init_packet, (AVPacket *pkt), "LIBAVFORMAT_52")
+{
+    av_log(NULL, AV_LOG_WARNING, "Diverting av_*_packet function calls to libavcodec. Recompile to improve performance\n");
+    av_init_packet(pkt);
+}
+#endif
 
 int av_get_packet(ByteIOContext *s, AVPacket *pkt, int size)
 {
diff --git a/libavutil/internal.h b/libavutil/internal.h
index 2faafc9..2d744df 100644
--- a/libavutil/internal.h
+++ b/libavutil/internal.h
@@ -196,4 +196,15 @@
 #   define NULL_IF_CONFIG_SMALL(x) x
 #endif
 
+#if HAVE_SYMVER_ASM_LABEL
+#   define FF_SYMVER(type, name, args, ver)             \
+    type ff_##name args __asm__ (#name "@" ver);        \
+    type ff_##name args
+#elif HAVE_SYMVER_GNU_ASM
+#   define FF_SYMVER(type, name, args, ver)             \
+    __asm__ (".symver ff_" #name "," #name "@" ver);    \
+    type ff_##name args;                                \
+    type ff_##name args
+#endif
+
 #endif /* AVUTIL_INTERNAL_H */
-- 
1.7.1


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