From a466e9abd9d847a4cffd570ffec3874ed172572c Mon Sep 17 00:00:00 2001
From: Shravan Mishra <s24mishra@uwaterloo.ca>
Date: Thu, 23 Feb 2017 12:51:14 -0500
Subject: [PATCH] Enable openssl and gmp dir to be specified

---
 configure.ac      | 33 ++++++++++++++++++++++++++++++---
 m4/macros/with.m4 | 24 ++++++++++++++++++++++++
 2 files changed, 54 insertions(+), 3 deletions(-)
 create mode 100644 m4/macros/with.m4

diff --git a/configure.ac b/configure.ac
index c11b253a1..5f98b649c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -17,6 +17,7 @@ AC_PROG_MKDIR_P
 AM_PROG_AS
 AM_INIT_AUTOMAKE([subdir-objects])
 m4_include(m4/macros/enable-disable.m4)
+m4_include(m4/macros/with.m4)
 LT_INIT([disable-shared])
 AC_CHECK_SIZEOF([size_t])
 # Checks for libraries.
@@ -74,18 +75,44 @@ AM_CONDITIONAL([sidhiqc], [test "x$sidhiqc" = xtrue])
 AM_CONDITIONAL([USE_SIDH_IQC], [test "x$sidhiqc" = xtrue])
 
 
+
 AM_CPPFLAGS="-g -std=gnu11 -Wpedantic -Wall -Wextra -DCONSTANT_TIME"
 AC_CANONICAL_HOST
 # Check for which host we are on and setup a few things
 # specifically based on the host
 case $host_os in
   darwin* )
-        OPENSSL_DIR=/usr/local/opt/openssl
-        GMP_DIR=/usr/local/opt/
+        AC_ARG_WITH(
+          [openssl-dir],
+          AS_HELP_STRING([--with-openssl-dir=dir],[openssl dir used locally (default /usr/local/opt/openssl).]),
+          [AC_DEFINE_UNQUOTED(OPENSSLDIR, [$withval], [OPENSSL DIR used locally])
+           AC_SUBST(OPENSSL_DIR, [$withval])],
+          [AC_SUBST(OPENSSL_DIR, /usr/local/opt/openssl)]
+        )
+        AC_ARG_WITH(
+          [gmp-dir],
+          AS_HELP_STRING([--with-gmp-dir=dir],[gmp dir used locally (default /usr/local/opt/).]),
+          [AC_DEFINE_UNQUOTED(GMPDIR, [$withval], [GMP DIR used locally])
+           AC_SUBST(GMP_DIR, [$withval])],
+          [AC_SUBST(GMP_DIR, /usr/local/opt/)]
+        )
         AM_CONDITIONAL([ON_DARWIN], [test xtrue = xtrue])
         ;;
   linux*)
-        OPENSSL_DIR=/usr
+        AC_ARG_WITH(
+          [openssl-dir],
+          AS_HELP_STRING([--with-openssl-dir=dir],[openssl dir used locally (default /usr).]),
+          [AC_DEFINE_UNQUOTED(OPENSSLDIR, [$withval], [OPENSSL DIR used locally])
+           AC_SUBST(OPENSSL_DIR, [$withval])],
+          [AC_SUBST(OPENSSL_DIR, /usr)]
+        )
+        AC_ARG_WITH(
+          [gmp-dir],
+          AS_HELP_STRING([--with-gmp-dir=dir],[gmp dir used locally (default /usr).]),
+          [AC_DEFINE_UNQUOTED(GMPDIR, [$withval], [GMP DIR used locally])
+           AC_SUBST(GMP_DIR, [$withval])],
+          [AC_SUBST(GMP_DIR, /usr)]
+        )
         if test x"${ac_cv_sizeof_size_t}" = x"8";then
           AM_CPPFLAGS=${AM_CPPFLAGS}" -DSIDH_ASM -march=x86-64"
         fi
diff --git a/m4/macros/with.m4 b/m4/macros/with.m4
new file mode 100644
index 000000000..3852af0a1
--- /dev/null
+++ b/m4/macros/with.m4
@@ -0,0 +1,24 @@
+# ARG_WITH_SUBST(option, default, help)
+# -----------------------------------
+# Create a --with-$1 option with helptext, AC_SUBST($1) to $withval/default
+AC_DEFUN([ARG_WITH_SUBST],
+	[AC_ARG_WITH(
+		[$1],
+		AS_HELP_STRING([--with-$1=arg], [$3 (default: $2).]),
+		[AC_SUBST(patsubst([$1], [-], [_]), ["$withval"])],
+		[AC_SUBST(patsubst([$1], [-], [_]), ["$2"])]
+	)]
+)
+
+# ARG_WITH_SET(option, default, help)
+# -----------------------------------
+# Create a --with-$1 option with helptext, set a variable $1 to $withval/default
+AC_DEFUN([ARG_WITH_SET],
+	[AC_ARG_WITH(
+		[$1],
+		AS_HELP_STRING([--with-$1=arg], [$3 (default: $2).]),
+		patsubst([$1], [-], [_])="$withval",
+		patsubst([$1], [-], [_])=$2
+	)]
+)
+