Default libraries linked in by gcc?

Question

Let's say I have a very simple C file (called foo.c):

int main()
{
   printf("foo");
   return 0;
}

Now I call gcc:

gcc foo.c

When I call gcc (with no options, as in the above example), what libraries are linked in by default and where are they located? (On Mac OS X 10.7)

Solution 1

The -v option to gcc will cause it to dump information about the default options it will use including the library paths and default libraries and object files that will be linked in.

If you give the -Wl,--verbose option, gcc will pass the --verbose to the linker which will dump exactly where it's looking for libraries, including both failed and successful searches.

Combine both options, and you'll see exactly what libraries are linked in, and why they're being linked in.

gcc -v foo.c -Wl,--verbose

Solution 2

ldd binary_name. http://www.opennet.ru/man.shtml?topic=ldd&category=1&russian=2

Comments

[Kevin Grant]

Note he said Mac OS X 10.7, where there is no ldd. The equivalent is otool -L.

[user1516425]

On my mac, ld says that --verbose is an unrecognized option

[Michael Burr]

@user1516425: oh - when I see gcc, I just assume that GNU ld is involved. Looking at some docs for the Xcode linker, developer.apple.com/library/mac/#documentation/Darwin/Refere‌​nce/…, you might want to see if the -t linker option will do the trick. Some other options to consider can be found under the "Options for introspecting the linker" heading on that page.