From e0b4ea2fd47d5281f66b0c92196296e2b133f388 Mon Sep 17 00:00:00 2001
From: Andrei Karas <akaras@inbox.ru>
Date: Tue, 7 Mar 2017 01:06:31 +0300
Subject: Auto detect if librt usable for current compiler.

---
 configure.ac | 110 +++++++++++++++++++++++++++++++----------------------------
 1 file changed, 57 insertions(+), 53 deletions(-)

diff --git a/configure.ac b/configure.ac
index 406fc3688..e7c32e112 100755
--- a/configure.ac
+++ b/configure.ac
@@ -3,6 +3,58 @@ AC_INIT([ManaPlus], [1.7.3.4], [akaras@inbox.ru], [manaplus])
 AM_INIT_AUTOMAKE([1.9])
 AC_LANG_CPLUSPLUS
 
+AC_DEFUN([AC_CHECK_CXX_FLAG],
+    [
+        AC_MSG_CHECKING([whether $CC supports $1])
+        OLD_CXXFLAGS="$CXXFLAGS"
+        CXXFLAGS="$CXXFLAGS -Werror $1"
+        test_flag=no
+        AC_COMPILE_IFELSE(
+            [AC_LANG_SOURCE([int foo;])],
+            [
+                AC_MSG_RESULT([yes])
+                test_flag=yes
+            ],
+            [
+                AC_MSG_RESULT([no])
+                test_flag=no
+            ]
+            CXXFLAGS="$OLD_CXXFLAGS"
+        )
+        AM_CONDITIONAL($2, test x$test_flag = xtrue)
+    ]
+)
+
+AC_DEFUN([AC_CHECK_LD_FLAG],
+    [
+        AC_MSG_CHECKING([whether $LD supports $1])
+        OLD_CXXFLAGS="$CXXFLAGS"
+        OLD_LDFLAGS="$LDFLAGS"
+        CXXFLAGS=""
+        LDFLAGS="$LDFLAGS $1"
+        test_flag=no
+        AC_LINK_IFELSE(
+            [AC_LANG_SOURCE([
+                int main(int argc, char **argv)
+                {
+                    return 0;
+                }
+            ])],
+            [
+                AC_MSG_RESULT([yes])
+                test_flag=yes
+            ],
+            [
+                AC_MSG_RESULT([no])
+                test_flag=no
+            ]
+            CXXFLAGS="$OLD_CXXFLAGS"
+            LDFLAGS="$OLD_LDFLAGS"
+        )
+        AM_CONDITIONAL($2, test x$test_flag = xyes)
+    ]
+)
+
 # Enable -Werror
 AC_ARG_ENABLE(werror,
 [  --enable-werror    Fail build if warning present],
@@ -456,8 +508,11 @@ if test "x$with_librt" == "xno"; then
 else
     if test "x$applebuild_enabled" == "xfalse"; then
         if test "x$androidbuild_enabled" == "xfalse"; then
-            AC_CHECK_LIB(rt, shm_open, ,
-            AC_MSG_ERROR([ *** Unable to find librt library]))
+            AC_CHECK_LD_FLAG(-lrt, USE_LIBRT)
+            if test "x$test_flag" == "xyes"; then
+                AC_CHECK_LIB(rt, shm_open, ,
+                AC_MSG_ERROR([ *** Unable to find librt library]))
+            fi
         fi
     fi
     without_librt=no
@@ -580,57 +635,6 @@ if test "x$naclbuild_enabled" == "xtrue"; then
     AC_CHECK_SDL()
 fi
 
-AC_DEFUN([AC_CHECK_CXX_FLAG],
-    [
-        AC_MSG_CHECKING([whether $CC supports $1])
-        OLD_CXXFLAGS="$CXXFLAGS"
-        CXXFLAGS="$CXXFLAGS -Werror $1"
-        test_flag=no
-        AC_COMPILE_IFELSE(
-            [AC_LANG_SOURCE([int foo;])],
-            [
-                AC_MSG_RESULT([yes])
-                test_flag=yes
-            ],
-            [
-                AC_MSG_RESULT([no])
-                test_flag=no
-            ]
-            CXXFLAGS="$OLD_CXXFLAGS"
-        )
-        AM_CONDITIONAL($2, test x$test_flag = xtrue)
-    ]
-)
-
-AC_DEFUN([AC_CHECK_LD_FLAG],
-    [
-        AC_MSG_CHECKING([whether $LD supports $1])
-        OLD_CXXFLAGS="$CXXFLAGS"
-        OLD_LDFLAGS="$LDFLAGS"
-        CXXFLAGS=""
-        LDFLAGS="$LDFLAGS $1"
-        test_flag=no
-        AC_LINK_IFELSE(
-            [AC_LANG_SOURCE([
-                int main(int argc, char **argv)
-                {
-                    return 0;
-                }
-            ])],
-            [
-                AC_MSG_RESULT([yes])
-                test_flag=yes
-            ],
-            [
-                AC_MSG_RESULT([no])
-                test_flag=no
-            ]
-            CXXFLAGS="$OLD_CXXFLAGS"
-            LDFLAGS="$OLD_LDFLAGS"
-        )
-        AM_CONDITIONAL($2, test x$test_flag = xyes)
-    ]
-)
 
 AC_CHECK_LD_FLAG(-rdynamic, HAVE_RDYNAMIC)
 
-- 
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