fix .gitignore: only ignore 'perl' in root of repo, not U/perl subdir

[metaconfig.git] / U / perl / Hasfield_t.U

?RCS: Copyright (c) 2016 Dagfinn Ilmari Mannsåker & H.Merijn Brand
?RCS:
?RCS: You may distribute under the terms of either the GNU General Public
?RCS: License or the Artistic License, as specified in the README file.
?RCS:
?X:
?X: This unit produces a variable that is intended to be eval'ed in
?X: order to define/undefine a symbol. A consistency check is made
?X: regarding any previous value and a warning is issued if there
?X: is any discrepancy.
?X:
?X: To use it, say:
?X:	set d_siginfo_si_errno siginfo_t int si_errno $d_sigaction signal.h
?X:	eval $hasfield_t;
?X:
?MAKE:Hasfield_t: test Compile rm_try Setvar
?MAKE:	-pick add $@ %<
?LINT:define hasfield_t
?S:hasfield_t:
?S:	Internal macro for Configure
?S:.
?V:hasfield_t:
?T:varname struct type field
: Define hasfield_t macro for Configure internal use
hasfield_t='varname=$1; struct=$2; type=$3; field=$4; shift; shift; shift; shift;
while $test $# -ge 2; do
    case "$1" in
	$define) echo "#include <$2>";;
    esac ;
    shift 2;
done > try.c;
echo "int main () { $struct foo; $type bar = foo.$field; }" >> try.c;
set try;
if eval $compile; then
	val="$define";
else
	val="$undef";
fi;
set $varname;
eval $setvar;
$rm_try'