Il 7/27/2013 6:46 PM, Bill Hammond ha scritto:
I am having trouble compiling an application that uses the libjpeg libraries
under cygwin64.
My program has compiled and run under cygwin32 for a long time. I can compile
and run it
under cygwin64 when I build and link against my own libjpeg.a. When I try and
download the
libjpeg-turbo libraries for cygwin64, it all comes apart. The "libjpeg-turbo"
package is
source only, and when I install "libjpeg-devel" and link against it with
"-ljpeg", all the
jpeg function calls are undefined.
I am using the cygwin64 installer. Is there a problem with the cygwin64 libjpeg
package(s),
or am I not doing something right?
Hi Bill,
could you show your link instruction ?
Have you a small test case ?
FYI the turbo devel package is : libturbojpeg-devel
Regards
Marco
So I installed the libturbojpeg-devel package, but I also had to install the
libjpeg-devel
package to get the proper include files added to /usr/include ("jconfig.h",
"jerror.h" and
so on).
I can successfully link my program against my own libjpeg with:
cc -g -lm -flto imgopt.o support.o ../common/jpeg.o ../common/gifread.o
../common/gifwrite.o ../common/image.o ../common/misc.o ../common/file.o
../common/fuzzy.o ../jpeg-8c/libjpeg.a -o a.exe
When I try and link against the system libraries (same when I use -lturbojpeg):
cc -g -lm -ljpeg -flto imgopt.o support.o ../common/jpeg.o ../common/gifread.o
../common/gifwrite.o ../common/image.o ../common/misc.o ../common/file.o
../common/fuzzy.o -o a.exe
try
cc -g -flto imgopt.o support.o ../common/jpeg.o ../common/gifread.o
../common/gifwrite.o ../common/image.o ../common/misc.o
../common/file.o ../common/fuzzy.o -o a.exe -lm -ljpeg
none of the libjpeg functions resolves:
/tmp/cc4EItUr.ltrans4.ltrans.o: In function `jpeg_write':
/home/proj/../common/jpeg.c:340: undefined reference to `jpeg_std_error'
/home/proj/../common/jpeg.c:340:(.text+0x102): relocation truncated to fit:
R_X86_64_PC32
against undefined symbol `jpeg_std_error'
/home/proj/../common/jpeg.c:349: undefined reference to `jpeg_destroy_compress'
etc...
I thought this might be another -flto problem, but compiling and linking
without it makes no
difference.
Thanks!
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