[Jason Dorje Short <address@hidden>] Bug#179086: autoconf: AC_DEFINE_UNQUOTED fails when used on variables

[Ben Pfaff]

The following bug was reported against the Debian GNU/Linux
packaging of Autoconf 2.57.  I am passing it along because I
suspect it is an upstream issue.

-------------------- Start of forwarded message --------------------
Subject: Bug#179086: autoconf: AC_DEFINE_UNQUOTED fails when used on variables
From: Jason Dorje Short <address@hidden>
To: Debian Bug Tracking System <address@hidden>
Date: Thu, 30 Jan 2003 15:28:47 -0500

I have code like

    ac_tr_lib=HAVE_LIB`echo $1 | sed -e 's/[^a-zA-Z0-9_]/_/g' \
    -e 'y/abcdefghijklmnopqrstuvwxyz/ABCDEFGHIJKLMNOPQRSTUVWXYZ/'`
    AC_DEFINE_UNQUOTED($ac_tr_lib)

which, is intended to define certain preprocessor variables depending on the
value it is given.  Under recent versions of autoconf, there is no acconfig.h
so the information it would have provided is now provided by autoheader.

According to the autoconf manual, AC_DEFINE_UNQUOTED is able to handle variables
as its first argument.  Yet it appears it cannot.  Perhaps autoheader must
extrapolate what possible values will be defined, and it just fails to do that
here.  Regardless, the result is that the value does not get defined, causing
(in this case) an obscure bug.

I can believe that autoheader is not capable of handling code like this.  But
what is bad is that the autoconf manual indicates this code will work -
and autoheader gives no warning that it is confused.  So what would be an
easy fix becomes a well-hidden bug.
-------------------- End of forwarded message --------------------

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