[FFmpeg-cvslog] Merge commit 'b2d5d6a7f20a255a5f3c9bf539cc507afd909ce5'

[Clément Bœsch]

ffmpeg | branch: master | Clément Bœsch <u at pkh.me> | Mon Jun 27 19:48:21 2016 +0200| [85a52a77ce879e2d41056f31730462fcca11c9ae] | committer: Clément Bœsch

Merge commit 'b2d5d6a7f20a255a5f3c9bf539cc507afd909ce5'

* commit 'b2d5d6a7f20a255a5f3c9bf539cc507afd909ce5':
  build: Only enable symbol reduction if the compiler does proper DCE

Merged-by: Clément Bœsch <u at pkh.me>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=85a52a77ce879e2d41056f31730462fcca11c9ae
---

 configure |   18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/configure b/configure
index 99cf017..007c953 100755
--- a/configure
+++ b/configure
@@ -6045,17 +6045,25 @@ enabled xmm_clobber_test &&
                   -Wl,--wrap,sws_scale ||
     disable xmm_clobber_test
 
-echo "X { local: *; };" > $TMPV
-if test_ldflags -Wl,${version_script},$TMPV; then
-    append SHFLAGS '-Wl,${version_script},\$(SUBDIR)lib\$(NAME).ver'
-    check_cc <<EOF && enable symver_asm_label
+check_ld "cc" <<EOF && enable proper_dce
+extern const int array[512];
+static inline int func(void) { return array[0]; }
+int main(void) { return 0; }
+EOF
+
+if enabled proper_dce; then
+    echo "X { local: *; };" > $TMPV
+    if test_ldflags -Wl,${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) { ${inline_asm+__asm__($quotes);} }
 EOF
-    check_cc <<EOF && enable symver_gnu_asm
+        check_cc <<EOF && enable symver_gnu_asm
 __asm__(".symver ff_foo,av_foo at VERSION");
 void ff_foo(void) {}
 EOF
+    fi
 fi
 
 if [ -z "$optflags" ]; then


======================================================================

diff --cc configure
index 99cf017,e68cd3e..007c953
--- a/configure
+++ b/configure
@@@ -6045,10 -4831,17 +6045,17 @@@ enabled xmm_clobber_test &
                    -Wl,--wrap,sws_scale ||
      disable xmm_clobber_test
  
- echo "X { local: *; };" > $TMPV
- if test_ldflags -Wl,${version_script},$TMPV; then
-     append SHFLAGS '-Wl,${version_script},\$(SUBDIR)lib\$(NAME).ver'
-     check_cc <<EOF && enable symver_asm_label
 -check_ld <<EOF && enable proper_dce
++check_ld "cc" <<EOF && enable proper_dce
+ extern const int array[512];
+ static inline int func(void) { return array[0]; }
+ int main(void) { return 0; }
+ EOF
+ 
+ if enabled proper_dce; then
+     echo "X { local: *; };" > $TMPV
+     if test_ldflags -Wl,${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) { ${inline_asm+__asm__($quotes);} }
  EOF