Re: Cross-build issues in gdb/gnulib

[<Paul_Koning@Dell.com>]

> On Aug 25, 2015, at 5:56 AM, Pedro Alves <palves@redhat.com> wrote:
> 
> On 08/24/2015 10:20 PM, Paul_Koning@Dell.com wrote:
>> I'm running into strange problems cross-building with V7.7.1; it looks like the same configure machinery is present in later versions as well.
>> 
>> The problem is that the configure script in gdb/gnulib tries to run a number of tests, by building and then executing "conftest".  It does so unconditionally, there are no checks for whether this is a cross-build, specifically build = x86_64-linux, host = target = netbsd.
> 
> I have no idea why configure is trying to run the test in your case, but I just yesterday
> updated master's gnulib copy to current upstream gnulib master.  Previously we had
> a 2012 copy.  I don't see any AC_TRY_RUN in current master, for instance,
> though I didn't check older versions.  In any case, try seeing if current master makes
> a difference.

I tracked down the spot in the configure sources where the problem originates.  There is no AC_TRY_RUN involved.  Instead, the issue is this bit of code in gnulib/import/m4/locale-ja.m4:

          # Test for the AIX locale name.
          if (LC_ALL=ja_JP LC_TIME= LC_CTYPE= ./conftest; exit) 2>/dev/null; then
            gt_cv_locale_ja=ja_JP

The comment refers to AIX, but it is in fact executed in the "*" case of a case statement, i.e., for everything other than Windows.  The same code pattern also appears in the two other locale-*.m4 files.

So it looks like that code needs some sort of guard checking for cross-build, and some sort of default action if so.  I'm not particularly fluent in configure unfortunately.

A quick look at the latest master shows that these files are unchanged by yesterday's update (other than copyright year).

	paul