RE: gdbserver cross compile

["Harris, Jeff" <JeffH at aiinet dot com>]

I tried setting both cross_compiling and ac_cv_prog_cc_cross environment
variables to "yes" before running configure.  Neither seemed to stop it from
running its program and overriding my values.

In thinking about setting ac_cv_header_stdc to yes, this also won't help
since the problem program, the one which checks ctype macros, will still be
run unless I can get cross_compiling to be set to "yes".

Jeff
-----Original Message-----
From: Daniel Jacobowitz [mailto:drow@mvista.com] 
Sent: Monday, May 05, 2003 5:35 PM
To: Harris, Jeff
Cc: gdb@sources.redhat.com
Subject: Re: gdbserver cross compile


On Mon, May 05, 2003 at 05:29:48PM -0400, Harris, Jeff wrote:
> I was having problems with getting gdbserver to correctly detect whether
it
> is being built with a cross-compiler or not.  I was trying to
cross-compile
> from i386 (RedHat 7.2) to i386(gcc 3.2.3 and glibc 2.3.2).  The configure
> script for gdbserver looks to have been created with an old version of
> autoconf (2.13 I believe).  The mechanism it uses to detect a cross
compiler
> simply tries to compile a simple program and run it.  If it runs, it
decides
> it isn't cross-compiling otherwise it is cross-compiling.  
> 
> My problem was that while this program runs with the cross-compiler, the
> program to detect whether standard C headers are used does not run.  As a
> result, the STDC_HEADERS #define is not set and ultimately a compile error
> to occur.
> 
> There doesn't seem to be a way to override the configure script's
detection
> mechanism.  However, if I rerun autoconf (version 2.53) in the gdbserver
> directory, the resulting configure script is updated to include better
> logic.  Basically, it compares the build and host options to configure to
> determine its cross-compile state.  This mechanism works for me since I
have
> different values for these options.
> 
> Is an updated version of configure something that would be considered for
> GDB 5.4?  

Sadly, no.  You can't use autoconf 2.5x with the current source tree,
in general; the conversion process is still being talked about.

It's pretty easy to fake out the 2.13 logic for this case.  I don't
remember exactly what the magic was, since I can't find any specific
reference to it in our cross build scripts; but all you should need to
do is preload one of the configure script's cache variables with
something that says no, don't run programs.

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer