Re: libtool is not wanting to play nicely with cross compiler

[Bob Friesenhahn]

On Mon, 6 Apr 2015, Andy Falanga (afalanga) wrote:

> I'm working on compiling some code for an ARM processor on a Xilinx 
> board.  I did not do the work of configuring the cross compiler and 
> so am ignorant about some parts of this process.

I recommend reading the Autoconf manual as pertains to 
cross-compilation.

How are your cross-tools named?  Tool naming is important.

What are the arguments that you passed to configure?

> I've finally gotten my configure script to complete and was running 
> the main compilation when I ran into this error:
>
> libtool: link: warning: 
> `/src/afalanga/crisscross/tmp/sysroots/zc706-zynq7/usr/lib/libstdc++.la' seems 
> to be moved
> libtool: link: warning: 
> `/src/afalanga/crisscross/tmp/sysroots/zc706-zynq7/usr/lib/libstdc++.la' seems 
> to be moved
> libtool: link: warning: 
> `/src/afalanga/crisscross/tmp/sysroots/zc706-zynq7/usr/lib/libstdc++.la' seems 
> to be moved
> /bin/grep: /usr/lib/libstdc++.la: No such file or directory
> /bin/sed: can't read /usr/lib/libstdc++.la: No such file or directory
> libtool: link: `/usr/lib/libstdc++.la' is not a valid libtool archive

The .la files are just text files which libtool uses to remember build 
information to be re-used when using the associated library.  The 
complaint about being moved is because these files are located in a 
different place than when they were originally installed (by whoever 
built/packaged them).  The .la file contains paths which are not 
correct for your current library installation.

> libtool is pointed in the right direction because the file 
> libstdc++.la, in the directory indicated, is the one it should be 
> using for cross compilation.  However, the file contains this:
>
> libdir='/usr/lib'
>
> I know this is the source of the warning, but why would I be getting 
> the warning?  If my understanding is correct, the stuff in this 
> directory is made into the image what it placed onto the embedded 
> system.  Thus, when that OS is running, libstdc++.la would actually 
> be in '/usr/lib'.
>
> However, it seems that libtool decides that it will look in 
> '/uar/lib' for libstdc++.la anyway and ignore that it found the file 
> where it was told it would.  Well, just as is indicated, there isn't 
> a libstdc++.la file in '/usr/lib'.  How do I make libtool happy with 
> the la archive (is that what they're called) that it should be 
> using?

Libtool does work for cross-compilation mode but tools must be named 
appropriately, autoconf arguments must be supplied appropriately, and 
the build toolchain needs to be smart enough to use its own sysroot 
for cross-compilation rather than accidentally using host system 
libraries/headers.

Not every configure script is appropriately prepared for 
cross-compilation since some tests are impossible when cross-compiling 
and so appropriate defaults need to be supplied.

Bob
--
Bob Friesenhahn
address@hidden, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/