[Vincent Lefevre] Bug#325866: autoconf: AC_COMPILE_IFELSE generates a test that doesn't work on IRIX64

[Ben Pfaff]

I'm forwarding the following bug reported against the Debian
packaging of upstream autoconf 2.59.  (Preserving the CC against
address@hidden in replies would be appreciated.)

-------------------- Start of forwarded message --------------------
Subject: Bug#325866: autoconf: AC_COMPILE_IFELSE generates a test that doesn't 
work on IRIX64
Date: Wed, 31 Aug 2005 14:05:28 +0200
From: Vincent Lefevre <address@hidden>
To: Debian Bug Tracking System <address@hidden>
Message-ID: <address@hidden>

Package: autoconf
Version: 2.59a-3
Severity: normal

AC_COMPILE_IFELSE generates a test that only checks the exit status
of the compiler command. But this is not sufficient:

demon ~ % uname -a
IRIX64 demon 6.5 01062343 IP35
demon ~ % cat tst.c
#ifdef FOO
# error "FOO is defined"
#endif
int main(void)
{
  return 0;
}
demon ~ % cc -DFOO tst.c && echo OK
cc-1035 cc: WARNING File = tst.c, Line = 2
  #error directive:  "FOO is defined"

  # error "FOO is defined"
    ^

OK
demon ~ %

An a.out program is generated. I'm not sure whether this is conforming
to the C standard, which says:

     [#4]  The  implementation shall not successfully translate a
     preprocessing   translation   unit   containing   a   #error
     preprocessing directive unless it is part of a group skipped
     by conditional inclusion.

i.e. could the implementation decide that the translation is not
successful because of the above warning? Anyway, one of the goals
of the configure script is to detect when things are wrong on the
current platform. So, I think that autoconf should cope with this
problem.

-- System Information:
Debian Release: testing/unstable
  APT prefers unstable
  APT policy: (500, 'unstable'), (500, 'stable')
Architecture: i386 (i686)
Shell:  /bin/sh linked to /bin/bash
Kernel: Linux 2.6.11.10-20050517
Locale: LANG=POSIX, LC_CTYPE=en_US.ISO8859-1 (charmap=ISO-8859-1)

Versions of packages autoconf depends on:
ii  debianutils                   2.14.2     Miscellaneous utilities specific t
ii  m4                            1.4.3-2    a macro processing language
ii  perl                          5.8.7-4    Larry Wall's Practical Extraction 

Versions of packages autoconf recommends:
ii  automake1.9 [automaken]       1.9.6-1    A tool for generating GNU Standard

-- no debconf information

-------------------- End of forwarded message --------------------

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