Re: BUG: library type search order

[Scott James Remnant]

On Wed, 2004-02-04 at 15:02, Peter O'Gorman wrote:

> Gary V. Vaughan wrote:
> |
> | I still don't see how this can help with the original search path vs. .la
> | files bug though (unless it was reported from a darwin box)...
> 
> Well, the original bug report was against 1.5, I think, so that was broken
> on all platforms.
> 
> I am curious about how Scott reproduced it on 1.5.2, unless he secretly
> switched from debian to darwin :)
> 
> Peter (running away)
> 
A DOUBTER!!  GET HIM BOYS!

Okay, I'm going to cheat and borrow libxml2 (my favourite test library)
and demonstrate this...

First we copy it into /opt/libxml/lib and make sure the paths in the .la
file are correct:

----8<--------8<--------8<--------8<--------8<--------8<--------8<--------8<----
descent ltsearchpatch% mkdir -p /opt/libxml/lib
descent ltsearchpatch% cp -a /usr/lib/libxml2.* /opt/libxml/lib
descent ltsearchpatch% sed -i -e "s,/usr/lib,/opt/libxml/lib,g" 
/opt/libxml/lib/libxml2.la
---->8-------->8-------->8-------->8-------->8-------->8-------->8-------->8----

What version of libtool am I running?

----8<--------8<--------8<--------8<--------8<--------8<--------8<--------8<----
descent ltsearchpatch% libtool --version
ltmain.sh (GNU libtool) 1.5.2 (1.1220.2.60 2004/01/25 12:25:08) Debian: 192 $
                                                                                
Copyright (C) 2003  Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
---->8-------->8-------->8-------->8-------->8-------->8-------->8-------->8----

Let's create a small test program and test-compile it, note that
/opt/libxml/lib/libxml2.la exists so this *should work* as expected.

----8<--------8<--------8<--------8<--------8<--------8<--------8<--------8<----
descent ltsearchpatch% echo "int main() { return 0; }" > test.c
descent ltsearchpatch% libtool --mode=compile gcc -c test.c
mkdir .libs
 gcc -c test.c  -fPIC -DPIC -o .libs/test.o
 gcc -c test.c -o test.o >/dev/null 2>&1
descent ltsearchpatch% libtool --mode=link gcc -o test test.lo 
-L/opt/libxml/lib -lxml2
gcc -o test .libs/test.o  -L/opt/libxml/lib /opt/libxml/lib/libxml2.so 
-lpthread -lz -lm  -Wl,--rpath -Wl,/opt/libxml/lib -Wl,--rpath 
-Wl,/opt/libxml/lib
---->8-------->8-------->8-------->8-------->8-------->8-------->8-------->8----

And it does, good, everything's sane.  We might as well create a test
library as well and make sure that works too...

----8<--------8<--------8<--------8<--------8<--------8<--------8<--------8<----
descent ltsearchpatch% echo "frobnitz() { }" > libtest.c descent ltsearchpatch% 
libtool --mode=compile gcc -c libtest.c
 gcc -c libtest.c  -fPIC -DPIC -o .libs/libtest.o
 gcc -c libtest.c -o libtest.o >/dev/null 2>&1
descent ltsearchpatch% libtool --mode=link gcc -o libtest.la libtest.lo -rpath 
/usr/local/lib -L/opt/libxml/lib -lxml2
gcc -shared  .libs/libtest.o  -Wl,--rpath -Wl,/opt/libxml/lib -Wl,--rpath 
-Wl,/opt/libxml/lib -L/opt/libxml/lib /opt/libxml/lib/libxml2.so  -Wl,-soname 
-Wl,libtest.so.0 -o .libs/libtest.so.0.0.0
(cd .libs && rm -f libtest.so.0 && ln -s libtest.so.0.0.0 libtest.so.0)
(cd .libs && rm -f libtest.so && ln -s libtest.so.0.0.0 libtest.so)
ar cru .libs/libtest.a  libtest.o
ranlib .libs/libtest.a
creating libtest.la
(cd .libs && rm -f libtest.la && ln -s ../libtest.la libtest.la)
---->8-------->8-------->8-------->8-------->8-------->8-------->8-------->8----

Good, all is right with the world; let's clean up and then REMOVE the
.la file in /opt/libxml/lib but leave the one in /usr/lib

----8<--------8<--------8<--------8<--------8<--------8<--------8<--------8<----
descent ltsearchpatch% libtool --mode=clean rm test libtest.la rm test
rm libtest.la .libs/libtest.so.0.0.0 .libs/libtest.so.0 .libs/libtest.so 
.libs/libtest.a .libs/libtest.la .libs/libtest.lai
rmdir .libs
descent ltsearchpatch% rm /opt/libxml/lib/libxml2.la
---->8-------->8-------->8-------->8-------->8-------->8-------->8-------->8----

Now let's build our test program again, you say this'll work, I say
this'll fail (ie. link /usr/lib/libxml2.so).

----8<--------8<--------8<--------8<--------8<--------8<--------8<--------8<----
descent ltsearchpatch% libtool --mode=link gcc -o test test.lo 
-L/opt/libxml/lib -lxml2
gcc -o test .libs/test.o  -L/opt/libxml/lib /usr/lib/libxml2.so
---->8-------->8-------->8-------->8-------->8-------->8-------->8-------->8----

nyah-nah nyah-nah-nah, told ya so! ;-)

What about linking with a library (which is, I have a feeling, what you
tested).

----8<--------8<--------8<--------8<--------8<--------8<--------8<--------8<----
descent ltsearchpatch% libtool --mode=link gcc -o libtest.la libtest.lo -rpath 
/usr/local/lib -L/opt/libxml/lib -lxml2
gcc -shared  .libs/libtest.o  -L/opt/libxml/lib -lxml2  -Wl,-soname 
-Wl,libtest.so.0 -o .libs/libtest.so.0.0.0
(cd .libs && rm -f libtest.so.0 && ln -s libtest.so.0.0.0 libtest.so.0)
(cd .libs && rm -f libtest.so && ln -s libtest.so.0.0.0 libtest.so)
ar cru .libs/libtest.a  libtest.o
ranlib .libs/libtest.a
creating libtest.la
(cd .libs && rm -f libtest.la && ln -s ../libtest.la libtest.la)
---->8-------->8-------->8-------->8-------->8-------->8-------->8-------->8----

An interesting result ... it actually doesn't specify *EITHER* full path
this time, and just passes -lxml2 to the linker this time round.  This
sounds like it might work, but you'll note it's also not passing 
-Wl,-rpath -Wl,/opt/libxml/lib so although the compiler linked it with
the right thing, the runtime path hasn't taken effect.


Just to verify this isn't a 1.5-specific problem, we'll do all of the
above with a 1.6 from a few weeks back (we've not changed anything since
then that should affect this):

----8<--------8<--------8<--------8<--------8<--------8<--------8<--------8<----
descent ltsearchpatch% libtool --version
ltmain.sh (GNU libtool 1.1370 2004/01/08 10:34:52) 1.5a
                                                                                
Copyright (C) 2004  Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

descent ltsearchpatch% libtool --mode=clean rm test libtest.la test.lo 
libtest.lo
rm test
rm libtest.la .libs/libtest.so.0.0.0 .libs/libtest.so.0 .libs/libtest.so 
.libs/libtest.a .libs/libtest.la .libs/libtest.lai
rm test.lo ./.libs/test.o ./test.o
rm libtest.lo ./.libs/libtest.o ./libtest.o
rmdir .libs
descent ltsearchpatch% cp /usr/lib/libxml2.la /opt/libxml/lib
descent ltsearchpatch% sed -i -e "s,/usr/lib,/opt/libxml/lib,g" 
/opt/libxml/lib/libxml2.la

descent ltsearchpatch% libtool --mode=compile gcc -c test.c mkdir .libs
 gcc -c test.c  -fPIC -DPIC -o .libs/test.o
 gcc -c test.c -o test.o >/dev/null 2>&1
descent ltsearchpatch% libtool --mode=link gcc -o test test.lo 
-L/opt/libxml/lib -lxml2
gcc -o test .libs/test.o  -L/opt/libxml/lib /opt/libxml/lib/libxml2.so 
-lpthread -lz -lm  -Wl,--rpath -Wl,/opt/libxml/lib -Wl,--rpath 
-Wl,/opt/libxml/lib

descent ltsearchpatch% libtool --mode=compile gcc -c libtest.c  gcc -c 
libtest.c  -fPIC -DPIC -o .libs/libtest.o
 gcc -c libtest.c -o libtest.o >/dev/null 2>&1
descent ltsearchpatch% libtool --mode=link gcc -o libtest.la libtest.lo -rpath 
/usr/local/lib -L/opt/libxml/lib -lxml2
gcc -shared  .libs/libtest.o  -Wl,--rpath -Wl,/opt/libxml/lib -Wl,--rpath 
-Wl,/opt/libxml/lib -L/opt/libxml/lib /opt/libxml/lib/libxml2.so  -Wl,-soname 
-Wl,libtest.so.0 -o .libs/libtest.so.0.0.0
(cd .libs && rm -f libtest.so.0 && ln -s libtest.so.0.0.0 libtest.so.0)
(cd .libs && rm -f libtest.so && ln -s libtest.so.0.0.0 libtest.so)
ar cru .libs/libtest.a  libtest.o
ranlib .libs/libtest.a
creating libtest.la
(cd .libs && rm -f libtest.la && ln -s ../libtest.la libtest.la)

descent ltsearchpatch% libtool --mode=clean rm test libtest.la rm test
rm libtest.la .libs/libtest.so.0.0.0 .libs/libtest.so.0 .libs/libtest.so 
.libs/libtest.a .libs/libtest.la .libs/libtest.lai
rmdir .libs
descent ltsearchpatch% rm /opt/libxml/lib/libxml2.la

descent ltsearchpatch% libtool --mode=link gcc -o test test.lo 
-L/opt/libxml/lib -lxml2
gcc -o test .libs/test.o  -L/opt/libxml/lib /usr/lib/libxml2.so

descent ltsearchpatch% libtool --mode=link gcc -o libtest.la libtest.lo -rpath 
/usr/local/lib -L/opt/libxml/lib -lxml2
gcc -shared  .libs/libtest.o  -L/opt/libxml/lib -lxml2  -Wl,-soname 
-Wl,libtest.so.0 -o .libs/libtest.so.0.0.0
(cd .libs && rm -f libtest.so.0 && ln -s libtest.so.0.0.0 libtest.so.0)
(cd .libs && rm -f libtest.so && ln -s libtest.so.0.0.0 libtest.so)
ar cru .libs/libtest.a  libtest.o
ranlib .libs/libtest.a
creating libtest.la
(cd .libs && rm -f libtest.la && ln -s ../libtest.la libtest.la)
---->8-------->8-------->8-------->8-------->8-------->8-------->8-------->8----

HEAD exhibits the same declared-wrong behaviour for the program, and the
same wrong-whichever-way-you-look-at-it behaviour for the library.

Scott
-- 
Have you ever, ever felt like this?
Had strange things happen?  Are you going round the twist?

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