Try searching for libsodium with pkg-config in ./configure.

If libsodium can't be found with PKG_CHECK_MODULES, try AC_CHECK_LIB. If that
also fails, abort configure. If a user passes --with-libsodium-libs explicitly,
that overrides the pkg-config found location.

1 files changed, 10 insertions, 2 deletions

diff --git a/configure.ac b/configure.ac
index 46162b44..14a723c6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -327,6 +327,14 @@ AC_SUBST(MATH_LDFLAGS)
 
 # Checks for libraries.
 
+PKG_CHECK_MODULES([LIBSODIUM], [libsodium],
+    [
+        LIBSODIUM_FOUND="yes"
+    ],
+    [
+        LIBSODIUM_FOUND="no"
+    ])
+
 if test "x$WANT_NACL" = "xyes"; then
     NACL_LIBS=
     NACL_LDFLAGS=
@@ -368,7 +376,7 @@ if test "x$WANT_NACL" = "xyes"; then
     AC_SUBST(NACL_LDFLAGS)
     AC_SUBST(NACL_OBJECTS)
     AC_SUBST(NACL_OBJECTS_PKGCONFIG)
-else
+elif test "x$LIBSODIUM_FOUND" = "xno"; then
     LIBSODIUM_LIBS=
     LIBSODIUM_LDFLAGS=
     LDFLAGS_SAVE="$LDFLAGS"
@@ -428,7 +436,7 @@ if test "x$WANT_NACL" = "xyes"; then
     CPPFLAGS="$CPPFLAGS_SAVE"
     AC_SUBST(NACL_CFLAGS)
     AC_DEFINE([VANILLA_NACL], [1], [use nacl instead of libsodium])
-else
+elif test "x$LIBSODIUM_FOUND" = "xno"; then
     LIBSODIUM_CFLAGS=
     CFLAGS_SAVE="$CFLAGS"
     CPPFLAGS_SAVE="$CPPFLAGS"