+# Enable silent rules by default
+AM_SILENT_RULES([yes])
+
+
+## ##
+## OS and Arch specific defaults ##
+## ##
+
+AS_CASE([$host],
+ [*-cygwin*], [LT_NO_UNDEFINED="-no-undefined"]
+)
+
+
+## ##
+## C compiler checks ##
+## ##
+
+# Choose the C compiler
+AC_PROG_CC
+# AC_PROG_CC_STDC was merged in AC_PROG_CC in autoconf 2.70
+m4_version_prereq([2.70], [], [AC_PROG_CC_STDC])
+
+# Make sure the C compiler supports C99
+AS_IF([test "$ac_cv_prog_cc_c99" = "no"], [AC_MSG_ERROR([The compiler does not support C99])])
+
+# Enable available system extensions and LFS support
+AC_USE_SYSTEM_EXTENSIONS
+AC_SYS_LARGEFILE
+
+# Make sure the C compiler supports __attribute__
+AX_C___ATTRIBUTE__
+AS_IF([test "x$ax_cv___attribute__" != "xyes"],
+ [AC_MSG_ERROR([The compiler does not support __attribute__ extensions])])
+
+# Make sure we have pthread support
+AX_PTHREAD([], [AC_MSG_ERROR([Could not configure pthread support])])
+
+# Make sure the C compiler supports weak symbols
+AX_SYS_WEAK_ALIAS
+AS_IF([test "x$ax_cv_sys_weak_alias" = "xno"],
+ [AC_MSG_ERROR([Your platform doesn't support weak symbols.])])
+
+# Checks for typedefs, structures, and compiler characteristics.
+AC_C_INLINE
+AC_C_TYPEOF
+AC_TYPE_INT32_T
+AC_TYPE_PID_T
+AC_TYPE_SIZE_T
+AC_TYPE_SSIZE_T
+AC_TYPE_UINT16_T
+AC_TYPE_UINT32_T
+AC_TYPE_UINT64_T
+AC_TYPE_UINT8_T