gcc4: ffmpeg vs. -freorder-functions

Tue Jul 14 18:08:00 GMT 2009

Dave,
I have been having some difficulties building the latest ffmpeg with 
gcc-4.3.2-2; the build would complete but the resulting binaries 
wouldn't launch due to the dreaded, ever-so-helpful C0000005 
initialization error. Building with gcc-3.4 worked just fine, as it has 
for some time on 1.5.
So after rebuilding ffmpeg dozens of times (literally) to eliminate 
possible causes one-by-one, I finally found that -O2 was the cause. 
Odd, since -O2 is generally safe, and ffmpeg even adds -O3 by default. 
So I went through all the flags which -O2 turns on, and the winner 
(loser?) is -freorder-functions.
Attached is a .cygport and patch which builds ffmpeg with minimal 
dependencies (libbz2 and zlib), and adds -fno-reorder-functions to 
CFLAGS (my default is "-O2 -march=i686 -pipe"), which produces working 
executables. If I remove -fno-reorder-functions, no such luck.
I know it's not exactly a STC, but hopefully I've narrowed this down 
enough that you can help me figure this out.
Yaakov
-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: ffmpeg-0.5-1.cygport
URL: <http://cygwin.com/pipermail/cygwin/attachments/20090714/2bc17ecd/attachment.ksh>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: r17736-cygwin.patch
Type: text/x-patch
Size: 1903 bytes
Desc: not available
URL: <http://cygwin.com/pipermail/cygwin/attachments/20090714/2bc17ecd/attachment.bin>
-------------- next part --------------
--
Problem reports: http://cygwin.com/problems.html
FAQ: http://cygwin.com/faq/
Documentation: http://cygwin.com/docs.html
Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple