From afc8712a9e6c72fbd03c36f84ecf8703e5d22a8c Mon Sep 17 00:00:00 2001
From: Christopher Larson <chris_larson@mentor.com>
Date: Mon, 15 Feb 2016 16:11:32 -0700
Subject: [PATCH 2/2] Add argument to control the libargp dependency

This ensures that the builds are always deterministic. If the argument isn't
passed, the default behavior is to use libargp if the libc doesn't have argp.

Upstream-Status: Pending
Signed-off-by: Christopher Larson <chris_larson@mentor.com>
---
 configure.ac | 55 ++++++++++++++++++++++++++++++++++++-------------------
 1 file changed, 36 insertions(+), 19 deletions(-)

diff --git a/configure.ac b/configure.ac
index 04fcd25..11a5321 100644
--- a/configure.ac
+++ b/configure.ac
@@ -32,6 +32,13 @@ AC_ARG_WITH([libgcrypt],
 	[with_libgcrypt=check]
 )
 
+AC_ARG_WITH([libargp],
+	AS_HELP_STRING([--without-libargp],
+		[Disable libargp support. Systems whose libc lacks argp can use libargp instead. (Default: check if libc lacks argp)]),
+	[with_libargp=$withval],
+	[with_libargp=check]
+)
+
 dnl Make sure anyone changing configure.ac/Makefile.am has a clue
 AM_MAINTAINER_MODE
 
@@ -82,27 +89,37 @@ AS_IF(
 	]
 )
 
-dnl First check if we have argp available from libc
-AC_LINK_IFELSE(
-	[AC_LANG_PROGRAM(
-		[#include <argp.h>],
-		[int argc=1; char *argv[]={"test"}; argp_parse(0,argc,argv,0,0,0); return 0;]
-		)],
-	[libc_has_argp="true"],
-	[libc_has_argp="false"]
+dnl Determine if we need libargp: either user requested, or libc has no argp
+AS_IF(
+	[test "x$with_libargp" != "xyes"],
+	[
+		AC_LINK_IFELSE(
+			[AC_LANG_PROGRAM(
+				[#include <argp.h>],
+				[int argc=1; char *argv[]={"test"}; argp_parse(0,argc,argv,0,0,0); return 0;]
+				)],
+			[need_libargp=no],
+			[need_libargp=yes
+			 if test "x$with_libargp" = "xno"; then
+				AC_MSG_FAILURE([libargp disabled and libc does not have argp])
+			 fi]
+		)
+	],
+	[need_libargp=yes],
 )
 
-dnl If libc doesn't provide argp, then test for libargp
-if test "$libc_has_argp" = "false" ; then
-	AC_MSG_WARN("libc does not have argp")
-	AC_CHECK_LIB([argp], [argp_parse], [have_argp="true"], [have_argp="false"])
-
-	if test "$have_argp" = "false"; then
-		AC_MSG_ERROR("no libargp found")
-	else
-		LIBS+=" -largp"
-	fi
-fi
+dnl Check for libargp
+AS_IF(
+	[test "x$need_libargp" = "xyes"],
+	[
+		AC_CHECK_LIB(
+			[argp],
+			[argp_parse],
+			[LIBS="$LIBS -largp"],
+			[AC_MSG_FAILURE([libargp not found])]
+		)
+	]
+)
 
 dnl -----------------
 dnl Configure options
-- 
2.2.1