GCC linker error while compiling a static library

Question

I want to create a static library of all my files so that i could give my mylib.a file to others to execute on their system. I use opencv library in my code. I used the following command to compile my code.

g++ index.cpp -o display1 -Wl,-Bdynamic pkg-config --cflags --libs opencv -lglut -lGL -lGLU -Wl,-Bstatic mylib.a

But it is giving the following error.

/usr/bin/ld: cannot find -lgcc_s
collect2: ld returned 1 exit status

Try g++ index.cpp -o display1 mylib.a $(pkg-config --cflags --libs opencv) -lglut -lGL -lGLU. — Kerrek SB
– Kerrek SB, Commented Aug 8, 2012 at 6:02
@JakobS.: That article describes evil hack to workaround serious misunderstanding of how linking is supposed to work on Linux by author of the mentioned tool. DON'T DO THAT. — Jan Hudec
– Jan Hudec, Commented Aug 8, 2012 at 7:16

Jan Hudec · Accepted Answer · 2012-08-08 07:39:01Z

I believe the Kerrek SB is right in the comment. The command should be

g++ index.cpp -o display1 mylib.a $(pkg-config --cflags --libs opencv) -lglut -lGL -lGLU

Explanation:

The -Wl,-Bdynamic and -Wl,-Bstatic flags are useless. The linker automatically picks static or dynamic library depending on what it finds. If you give it path to a library (as you do with mylib.a) it can't choose and will link the library you provided. If you give it an -lX flag, it will look for libX.so or libX.a and link whichever it finds, but most Linux installations won't have static variants of system libraries, so there is nothing to choose from either.
It's worse, the -Wl,-Bdynamic and -Wl,-Bstatic are wrong. -Wl,-Bstatic prohibits linking of shared libraries. That has the side-effect of selecting static libgcc, which implicitly comes last on the linker command line. And you don't seem to have that installed. Most Linux systems don't.
Each object must be listed on the command-line before the libraries it refers to. I would expect mylib.a contains functions that need opencv or opengl, so it must be listed before those -l flags.

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