# OT: compilation probs (later extension) **URL:** \ **Category:** Ruby\ **Created:** [September 13, 2006, 7:33pm UTC](https://www.ruby-forum.com/t/ot-compilation-probs-later-extension/68586 "2006-09-13T19:33:58Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![Hugh\_S](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/d2c977/32.png) [@Hugh\_S](https://www.ruby-forum.com/u/Hugh_S)\ **Post date:** [September 13, 2006, 7:33pm UTC](https://www.ruby-forum.com/t/ot-compilation-probs-later-extension/68586/1 "2006-09-13T19:33:58Z")
This is somewhat OT for Ruby-Talk, but I want to build this against Ruby later, and Ruby is built with GCC. I suppose I could make another one built with Sun’s cc, put it somewhere else, but I’d consider that a violation of DRY. Anyway, my question which I’ve been wrestling with for over a week, and which help from the gcc-help list hasn’t solved for me, is: Compiling my application (which uses FFTW 3.1) with the Sun cc works, and I get an executable, but compiling it with gcc I get errors of the form: ``` [...] ``` gcc -R/usr/local/lib -g -I/usr/local/include -z verbose -z rescan -L/progs/SUNWspro/lib:/usr/local/lib:/usr/local/lib/sparcv9:/usr/lib:/usr/share/lib:/usr/dt/lib:/usr/openwin/lib:/opt/panorama/lib:/opt/sfw/lib -lfftw3 -lm -ll -lpng -lz -o fsv fsv.o fft\_2d\_filter.o y.tab.o lex.yy.o fft\_2d\_filter.o: In function `fft_2d_forward': /home/hgs/fsv/fft_2d_filter.c:30: undefined reference to`fftw\_plan\_dft\_r2c\_2d’ /home/hgs/fsv/fft\_2d\_filter.c:31: undefined reference to `fftw_execute' fft_2d_filter.o: In function`fft\_2d\_inverse’: […] collect2: ld returned 1 exit status gmake: \*\*\* [fsv] Error 1 The fftw3 library exists, as do the png libraries, I recently tried adding the -R option into the build of fftw3 so that the paths to the libraries would get built in, but I get the same errors anyway. I thought my libraries might be in the wrong order, and putting -lz after -lpng got rid of the errors like: /usr/local/lib/gcc/sparc-sun-solaris2.9/4.1.0/…/…/…/libpng.so: undefined reference to `deflate' /usr/local/lib/gcc/sparc-sun-solaris2.9/4.1.0/../../../libpng.so: undefined reference to`inflate’ […] I don’t really know how to get that right in future. I tried using lorder and tsort but that produces a huge amount of output (in /usr/local/lib): bash-2.05$ ls lib{fftw\*,z\*,png\*} | xargs lorder | tsort |wc /usr/ccs/bin/nm: libfftw3.la: invalid file type 352 352 3946 bash-2.05$ Can anyone help me out with this, or have I entered a really obscure area of C programming? Sorry for the OT nature of this, but I want to get to the bottom of this, or I’m just “programming by coincidence”. The difference between witchcraft and science… There is no fftw3 list, which is hardly an excuse. ``` Thank you, Hugh ``` ---
**Author:** ![Hugh\_S](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/d2c977/32.png) [@Hugh\_S](https://www.ruby-forum.com/u/Hugh_S)\ **Post date:** [September 13, 2006, 8:26pm UTC](https://www.ruby-forum.com/t/ot-compilation-probs-later-extension/68586/2 "2006-09-13T20:26:03Z")
Hi, At Thu, 14 Sep 2006 02:32:33 +0900, Hugh S. wrote in [ruby-talk:214307]: > gcc -R/usr/local/lib -g -I/usr/local/include -z verbose -z rescan -L/progs/SUNWspro/lib:/usr/local/lib:/usr/local/lib/sparcv9:/usr/lib:/usr/share/lib:/usr/dt/lib:/usr/openwin/lib:/opt/panorama/lib:/opt/sfw/lib -lfftw3 -lm -ll -lpng -lz -o fsv fsv.o fft\_2d\_filter.o y.tab.o > lex.yy.o > fft\_2d\_filter.o: In function `fft_2d_forward': /home/hgs/fsv/fft_2d_filter.c:30: undefined reference to`fftw\_plan\_dft\_r2c\_2d’ > /home/hgs/fsv/fft\_2d\_filter.c:31: undefined reference to `fftw_execute' fft_2d_filter.o: In function`fft\_2d\_inverse’: > […] > collect2: ld returned 1 exit status > gmake: \*\*\* [fsv] Error 1 Move -l options after \*.o.