Long paths with ../../../../ throughout

[Ian Lance Taylor]

Jon Grant <jg@jguk.org> writes:

> Any easy way to evaluate and reduce command lines? Consider this:
>
> /usr/lib/gcc/i486-linux-gnu/4.3.3/../../../../lib/crt1.o
>
> Is actually the same as: /usr/lib/crt1.o  -- which is much clearer!

Using this form of path makes it easy to move an installed gcc tree to
a new location and have it continue to work correctly.  Since normal
users never see these paths, the goal is correctness rather than
clarity.

> Also I notice lots of duplicate parameters:
> 
> Is this directory really needed twice?
> -L/usr/lib/gcc/i486-linux-gnu/4.3.3 -L/usr/lib/gcc/i486-linux-gnu/4.3.3

No.  I would encourage you to investigate why it is happening.

> also -lgcc_s is mentioned twice, as is -gcc

This is because on some systems there is a circular dependency between
-lgcc and -lc.  Some of the functions in -lgcc require functions in
-lc.  If -lc was compiled with gcc, then on some systems some of the
functions in -lc will require -lgcc.  Fortunately the functions which
-lc requires in -lgcc will never themselves require -lc.  So
mentioning -lgcc twice, once before -lc and once after, suffices on
all systems.

> Finally, could collect2 output command lines  when in -verbose mode?
> Currently I can't see what parameters it is calling "ld" with.. when
> ld fails.

To see what collect2 is doing, use -Wl,-debug.

Ian