absolute library path handling issue

[bdbaddog]

This issue was originally created at: 2013-07-22 18:23:46.
This issue was reported by: brianw1.

brianw1 said at 2013-07-22 18:23:46

When specifying an absolute path to a library, the extension is stripped resulting in gcc being unable to find the file.

Example:

env = Environment(LIBS=['/usr/lib/foo.so'])

This becomes -l/usr/lib/foo when given as an argument to gcc rather than -l/usr/lib/foo.so

Of course, including /usr/lib/foo.so as a source file works properly but in this case I am getting libraries from pkg-config --libs pkg_name in the form -l:/usr/lib/foo.so and using ParseConfig which places these in the LIBS list.

My current workaround is to filter out all libs with a ':' prefix and instead include them as source files after all my sources.

Note that the ':' is used to prefix the lib path because pkg-config will otherwise re-order libs by moving those without a -l prefix to the front.

brianw1 said at 2013-07-22 19:02:02

Correction, I missed the leading ':' in the example.

Example:

env = Environment(LIBS=[':/usr/lib/foo.so'])

This becomes -l:/usr/lib/foo when given as an argument to gcc rather than -l:/usr/lib/foo.so

ajf58 said at 2014-08-17 08:36:15

The documentation for SCons 2.3.2 http://www.scons.org/doc/2.3.2/HTML/scons-user.html#cv-LIBS is that to do this you could use a File object in the list. Given that you're using pkg-config I'd recommend using the ParseConfig function http://www.scons.org/doc/production/HTML/scons-user.html#sect-parseconfig.

I'd suggest this issue is marked as won't fix, unless anyone objects?

[mwichmann]

Isn't there another issue on this topic? The gcc leading-colon syntax is not currently recognized by SCons.

[mwichmann]

See also issue #2743, #2925 and #3951. I'm thinking we should be able to collapse these down to one (or maybe just close all four with one PR).

[mwichmann]

So now we have (documented, once 4.6 releases) two ways to give more "literal" paths, which aren't first stripped by SCOns - the : introducer from the GNU linker, set via LIBLITERALPREFIX, and using a File object. Closing this as fixed via #4429.

[mwichmann]

Hmmm, reopening for now. Would like to check if a library specified this was from pkg-config is handled by ParseFlags - in theory it should work but is untested.

[mwichmann]

Okay, can manually confirm this works - if the string returned by pkg-config contains the literal-library syntax, it is passed through the chain and ends up correct, like this sample:

scons -n -Q
gcc -o hello.o -c -DSOMETHING -DVARIABLE=2 hello.c
gcc -o hello hello.o -L/usr/lib -lother -l:libliteral.a

So I will close this one (if someone thinks a formal test is needed for that, feel free to reopen)