+#undef _GLIBCXX_USE_WCHAR_T
+
+// Define if using setrlimit to limit memory usage during 'make check'.
+#undef _GLIBCXX_MEM_LIMITS
+
+// Define to use concept checking code from the boost libraries.
+#undef _GLIBCXX_CONCEPT_CHECKS
+
+// Define to use symbol versioning in the shared library.
+#undef _GLIBCXX_SYMVER
+
+// Define symbol versioning in assember directives. If symbol
+// versioning is beigng used, and the assembler supports this kind of
+// thing, then use it.
+// NB: _GLIBCXX_AT_AT is a hack to work around quoting issues in m4.
+#if _GLIBCXX_SYMVER
+ #define _GLIBCXX_ASM_SYMVER(cur, old, version) \
+ asm (".symver " #cur "," #old _GLIBCXX_AT_AT #version);
+#else
+ #define _GLIBCXX_ASM_SYMVER(cur, old, version)
+#endif
+
+// Define if gthr-default.h exists (meaning that threading support is enabled).
+#undef HAVE_GTHR_DEFAULT
+
+// Define if drand48 exists.
+#undef HAVE_DRAND48
+
+// Define if getpagesize exists.
+#undef HAVE_GETPAGESIZE
+
+// Define if setenv exists.
+#undef HAVE_SETENV
+
+// Define if sigsetjmp exists.
+#undef HAVE_SIGSETJMP
+
+// Define if mbstate_t exists in wchar.h.
+#undef HAVE_MBSTATE_T
+
+// Define if you have the modff function.
+#undef HAVE_MODFF
+
+// Define if you have the modfl function.
+#undef HAVE_MODFL
+
+// Define if you have the expf function.
+#undef HAVE_EXPF
+
+// Define if you have the expl function.
+#undef HAVE_EXPL
+
+// Define if you have the hypotf function.
+#undef HAVE_HYPOTF
+
+// Define if you have the hypotl function.
+#undef HAVE_HYPOTL