Autoconf detection of Perl5 and Perl5 modules

Add m4 macros for checking for perl modules (JSON)

Fix #74, #29.

Signed-off-by: Nico Williams <nico@twosigma.com>

cf/krb-prog-perl.m4

@@ -0,0 +1,21 @@
+dnl
+dnl perl and some of its module are required to build some headers
+dnl
+
+AC_DEFUN([AC_KRB_PROG_PERL],
+[AC_CHECK_PROGS(PERL, perl, perl)
+if test "$PERL" = ""; then
+  AC_MSG_ERROR([perl not found - Cannot build Heimdal without perl])
+fi
+])
+
+AC_DEFUN([AC_KRB_PERL_MOD],
+[
+AC_MSG_CHECKING([for Perl5 module $1])
+if ! $PERL -M$1 -e 'exit(0);' >/dev/null 2>&1; then
+  AC_MSG_RESULT([no])
+  AC_MSG_ERROR([perl module $1 not found - Cannot build Heimdal without perl module $1])
+else
+  AC_MSG_RESULT([yes])
+fi
+])

configure.ac

@@ -45,6 +45,17 @@ AC_DEFINE([_GNU_SOURCE], 1,
 AC_OBJEXT
 AC_EXEEXT
 
+dnl
+dnl this is needed when der-protos.h or der-private.h has to be generated
+dnl
+if ! test -f "$srcdir/lib/asn1/der-protos.h" ||
+   ! test -f "$srcdir/lib/asn1/der-private.h"; then
+    AC_KRB_PROG_PERL
+    AC_KRB_PERL_MOD(Getopt::Std)
+    AC_KRB_PERL_MOD(File::Compare)
+    AC_KRB_PERL_MOD(JSON)
+fi
+
 dnl AC_KRB_PROG_YACC
 AC_PROG_YACC
 AM_PROG_LEX
@@ -100,7 +111,6 @@ AC_SUBST([ASN1_COMPILE_DEP])
 AC_SUBST([SLC])
 AC_SUBST([SLC_DEP])
 
-
 dnl ---
 
 AC_DEFINE(HEIM_WEAK_CRYPTO, 1, [Define if you want support for weak crypto])