Telling gcc directly to link a library statically

156
votes

It feels strange to me to use -Wl,-Bstatic in order to tell gcc which libraries I want to link with statically. After all I'm telling gcc directly all other information about linking with libraries (-Ldir, -llibname).

Is it possible to tell the gcc driver directly which libraries should be linked statically?

Clarification: I know that if a certain library exists only in static versions it'll use it without -Wl,-Bstatic, but I want to imply gcc to prefer the static library. I also know that specifying the library file directly would link with it, but I prefer to keep the semantic for including static and dynamic libraries the same.

2
gcclinkerstatic-librariesdynamic-linking

2 Answers

233
votes

Use -l: instead of -l. For example -l:libXYZ.a to link with libXYZ.a. Notice the lib and .a are written out, as opposed to -lXYZ which would auto-expand to libXYZ.so/libXYZ.a.

It is an option of the GNU ld linker:

-l namespec ... If namespec is of the form :filename, ld will search the library path for a file called filename, otherwise it will search the library path for a file called libnamespec.a. ... on ELF ... systems, ld will search a directory for a library called libnamespec.so before searching for one called libnamespec.a. ... Note that this behavior does not apply to :filename, which always specifies a file called filename."

(Since binutils 2.18)

Note that this only works with the GNU linker. If your ld isn't the GNU one you're out of luck.

151
votes

You can add .a file in the linking command:

  gcc yourfiles /path/to/library/libLIBRARY.a

But this is not talking with gcc driver, but with ld linker as options like -Wl,anything are.

When you tell gcc or ld -Ldir -lLIBRARY, linker will check both static and dynamic versions of library (you can see a process with -Wl,--verbose). To change order of library types checked you can use -Wl,-Bstatic and -Wl,-Bdynamic. Here is a man page of gnu LD: http://linux.die.net/man/1/ld

To link your program with lib1, lib3 dynamically and lib2 statically, use such gcc call:

gcc program.o -llib1 -Wl,-Bstatic -llib2 -Wl,-Bdynamic -llib3

Assuming that default setting of ld is to use dynamic libraries (it is on Linux).