[FFmpeg-cvslog] configure: fix linking with MSVC when using --disable-optimizations

[Steve Lhomme]

ffmpeg | branch: master | Steve Lhomme <robux4 at gmail.com> | Thu Dec 15 18:00:56 2016 +0100| [f7174d7ed045445d00a6d557236737d09ad32343] | committer: Diego Biurrun

configure: fix linking with MSVC when using --disable-optimizations

Without any optimization flags, MSVC does no dead code elimination (DCE) at
all, even for the most trivial cases. DCE is a prerequisite for building libav
correctly, otherwise there are undefined references to functions for other
architectures and disabled components.

-O1 is the minimal optimization flag for MSVC that does include DCE.

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=f7174d7ed045445d00a6d557236737d09ad32343
---

 configure | 1 +
 1 file changed, 1 insertion(+)

diff --git a/configure b/configure
index 25640ebb7f..2ecd0ed718 100755
--- a/configure
+++ b/configure
@@ -3279,6 +3279,7 @@ probe_cc(){
         _DEPFLAGS='$(CPPFLAGS) $(CFLAGS) -showIncludes -Zs'
         _cflags_speed="-O2"
         _cflags_size="-O1"
+        _cflags_noopt="-O1"
         if $_cc -nologo- 2>&1 | grep -q Linker; then
             _ld_o='-out:$@'
         else