More than one lib file

More than one lib file

[greg zhang]

Hi,

Now, I have a question about gcc and libstdc++ lib.

In a server machine, there are two different lib
files(libstdc++), how to let everyone link correct lib
when they build their differenet projects.
Maybe they build simultaneously, so I can't modify lib
directory manually.

I try to modify lib directory in Makefile, such as
/usr/local/lib, or /usr/local/lib2, ...

(through change envirment variable LD_LIBRARY_PATH =
one of them)

It seems gcc always search and link the previous lib
file(/usr/local/lib).

So, could give me a advice how and where to begin
this?

Thanks.


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Re: More than one lib file

[Martin v. Loewis]

> So, could give me a advice how and where to begin
> this?

Are they using two different gcc installations as well? If so, you can
put libstdc++ into the directory where cc1plus lives; gcc will pick it
up from there. After you've made the change, you should verify with
gcc -v that it does the right thing.

Regards,
Martin

Re: More than one lib file

[Alexandre Oliva]

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On Mar 10, 2000, "Martin v. Loewis" <martin@loewis.home.cs.tu-berlin.de> wrote:

>> So, could give me a advice how and where to begin
>> this?

> Are they using two different gcc installations as well? If so, you can
> put libstdc++ into the directory where cc1plus lives; gcc will pick it
> up from there. After you've made the change, you should verify with
> gcc -v that it does the right thing.

It's not just a matter of GCC finding the right library: if it's a
dynamic library, the executable will have to find it too, and that's
where the problems may start.  If the library sonames are different,
there should be no problem if both are in /usr/local/lib.  But if
they're not, you may have to add -R/path/to/the/right/library to the
link command in order for the executable to find the appropriate
library at run-time.

-- 
Alexandre Oliva     http://www.ic.unicamp.br/~oliva/     Enjoy Guaraná
Cygnus Solutions, a Red Hat company        aoliva@{redhat, cygnus}.com
Free Software Developer and Evangelist    CS PhD student at IC-Unicamp
oliva@{lsd.ic.unicamp.br, gnu.org}   Write to mailing lists, not to me

Re: More than one lib file

[Alexandre Oliva]

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On Mar 10, 2000, "Martin v. Loewis" <martin@loewis.home.cs.tu-berlin.de> wrote:

>> So, could give me a advice how and where to begin
>> this?

> Are they using two different gcc installations as well? If so, you can
> put libstdc++ into the directory where cc1plus lives; gcc will pick it
> up from there. After you've made the change, you should verify with
> gcc -v that it does the right thing.

It's not just a matter of GCC finding the right library: if it's a
dynamic library, the executable will have to find it too, and that's
where the problems may start.  If the library sonames are different,
there should be no problem if both are in /usr/local/lib.  But if
they're not, you may have to add -R/path/to/the/right/library to the
link command in order for the executable to find the appropriate
library at run-time.

-- 
Alexandre Oliva     http://www.ic.unicamp.br/~oliva/     Enjoy Guaraná
Cygnus Solutions, a Red Hat company        aoliva@{redhat, cygnus}.com
Free Software Developer and Evangelist    CS PhD student at IC-Unicamp
oliva@{lsd.ic.unicamp.br, gnu.org}   Write to mailing lists, not to me

Re: More than one lib file

[Martin v. Loewis]

> So, could give me a advice how and where to begin
> this?

Are they using two different gcc installations as well? If so, you can
put libstdc++ into the directory where cc1plus lives; gcc will pick it
up from there. After you've made the change, you should verify with
gcc -v that it does the right thing.

Regards,
Martin

More than one lib file

[greg zhang]

Hi,

Now, I have a question about gcc and libstdc++ lib.

In a server machine, there are two different lib
files(libstdc++), how to let everyone link correct lib
when they build their differenet projects.
Maybe they build simultaneously, so I can't modify lib
directory manually.

I try to modify lib directory in Makefile, such as
/usr/local/lib, or /usr/local/lib2, ...

(through change envirment variable LD_LIBRARY_PATH =
one of them)

It seems gcc always search and link the previous lib
file(/usr/local/lib).

So, could give me a advice how and where to begin
this?

Thanks.


__________________________________________________
Do You Yahoo!?
Talk to your friends online with Yahoo! Messenger.
http://im.yahoo.com