Linking Math Library in GCC 4.6.1 (Ubuntu 11.10)

Question

I find a problem in the linking process of my application. I did not have the same with gcc 4.5. It tries to link math library with the following command.

gcc -W         


        

Answer 1

I've had the same problem with gcc 4.6.1, even with only one library. This doesn't work:

$ gcc -lm eg.o -o eg
eg.o: In function `foo':
/home/nick/tmp/eg.c:5: undefined reference to `sqrt'
collect2: ld returned 1 exit status

But this does:

$ gcc eg.o -o eg -lm

I hit this because I was using "LDFLAGS=-lm" in my Makefile. Works fine if you use "LDLIBS=-lm" instead.