Re: Package dependencies in cross gcc

[Phil Endecott <phil_qtefy_endecott@chezphil.org>]

Hi Nikita, thanks for your reply.

Nikita V. Youshchenko wrote:
> > Now I am trying to cross-compile some more ambitious code, and I'm
> > encountering difficulties.  In particular it seems that the libstdc++
> > that I built built is inferior to the native one; I think that configure
> > decided that some platform headers (sys/time.h, for example) were
> > missing and disabled some things.
>
> This is strange.
> Could you please post some details (what exactly you tried to compile, what 
> is written to config.log when tests behave unexpectedly, ...)?

I have Boost installed via dpkg-cross, and tried to compile this minimal 
example:

#include <boost/config/requires_threads.hpp>

It should do nothing, but instead I get a #error telling me that I don't 
have threads.

As you can imagine, debugging this back to the underlying problem would 
be a challenge.  So I decided to try the native libraries instead.  I 
then noticed the differences in 
/usr/armeb-linux/include/c++/3.3/armeb-linux/bits/c++config.h.  Here are 
the things that my cross version is missing:

#define _GLIBCPP_MEM_LIMITS 1
#define _GLIBCPP_HAVE_DRAND48 1
#define _GLIBCPP_HAVE_GETPAGESIZE 1
#define _GLIBCPP_HAVE_SETENV 1
#define _GLIBCPP_HAVE_SIGSETJMP 1
#define _GLIBCPP_HAVE___BUILTIN_ABS 1
#define _GLIBCPP_HAVE___BUILTIN_LABS 1
#define _GLIBCPP_HAVE___BUILTIN_COS 1
#define _GLIBCPP_HAVE___BUILTIN_COSF 1
#define _GLIBCPP_HAVE___BUILTIN_COSL 1
#define _GLIBCPP_HAVE___BUILTIN_FABS 1
#define _GLIBCPP_HAVE___BUILTIN_FABSF 1
#define _GLIBCPP_HAVE___BUILTIN_FABSL 1
#define _GLIBCPP_HAVE___BUILTIN_SIN 1
#define _GLIBCPP_HAVE___BUILTIN_SINF 1
#define _GLIBCPP_HAVE___BUILTIN_SINL 1
#define _GLIBCPP_HAVE_LC_MESSAGES 1
#define _GLIBCPP_HAVE_DRAND48 1
#define _GLIBCPP_HAVE_GETPAGESIZE 1
#define _GLIBCPP_HAVE_HYPOT 1
#define _GLIBCPP_HAVE_ISATTY 1
#define _GLIBCPP_HAVE_SETENV 1
#define _GLIBCPP_HAVE_GCONV_H 1
#define _GLIBCPP_HAVE_SYS_RESOURCE_H 1
#define _GLIBCPP_HAVE_SYS_STAT_H 1
#define _GLIBCPP_HAVE_SYS_TIME_H 1
#define _GLIBCPP_HAVE_UNISTD_H 1
#define _GLIBCPP_HAVE_SIGSETJMP 1
#define _GLIBCPP_HAVE_MEMLIMIT_DATA 1
#define _GLIBCPP_HAVE_MEMLIMIT_RSS 1
#define _GLIBCPP_HAVE_MEMLIMIT_VMEM 0
#define _GLIBCPP_HAVE_MEMLIMIT_AS 1

(In the cross version, each one is like
  /* #undef XXXXXX */
)

I've looked in the libstdc++ config.log and, as far as I can see, it 
doesn't mention these things.  For example, sys/time.h is not mentioned 
in the file, while in the libiberty config.log I see a sucessful test.

Before building gcc etc. I installed dpkg-cross'd versions of 
linux-kernel-headers, libdb1-compat, libc6 and libc6-dev.  Perhaps I 
should have installed some other packages to provide whatever configure 
has not found?


Thanks for your help.

--Phil.