+#ifndef ATTRIBUTE_UNUSED
+# define ATTRIBUTE_UNUSED __attribute__ ((__unused__))
+#endif
+
+#define FUNCTION_PRINT() fprintf (stderr, "%s: ", __func__)
+
+/*------.
+| NLS. |
+`------*/
+
+#include <locale.h>
+
+#include <gettext.h>
+#define _(Msgid) gettext (Msgid)
+#define N_(Msgid) (Msgid)
+
+
+/*-----------.
+| Booleans. |
+`-----------*/
+
+#include <stdbool.h>
+
+
+
+/*-------------.
+| Assertions. |
+`-------------*/
+
+/* <assert.h>'s assertions are too heavyweight, and can be disabled
+ too easily, so use aver rather than assert. */
+static inline void
+aver (bool assertion)
+{
+ if (! assertion)
+ abort ();
+}
+
+
+/*-----------.
+| Obstacks. |
+`-----------*/
+
+#define obstack_chunk_alloc xmalloc
+#define obstack_chunk_free free
+#include <obstack.h>
+
+#define obstack_sgrow(Obs, Str) \
+ obstack_grow (Obs, Str, strlen (Str))
+
+#define obstack_fgrow1(Obs, Format, Arg1) \
+do { \
+ char buf[4096]; \
+ sprintf (buf, Format, Arg1); \
+ obstack_grow (Obs, buf, strlen (buf)); \
+} while (0)
+
+#define obstack_fgrow2(Obs, Format, Arg1, Arg2) \
+do { \
+ char buf[4096]; \
+ sprintf (buf, Format, Arg1, Arg2); \
+ obstack_grow (Obs, buf, strlen (buf)); \
+} while (0)
+
+#define obstack_fgrow3(Obs, Format, Arg1, Arg2, Arg3) \
+do { \
+ char buf[4096]; \
+ sprintf (buf, Format, Arg1, Arg2, Arg3); \
+ obstack_grow (Obs, buf, strlen (buf)); \
+} while (0)
+
+#define obstack_fgrow4(Obs, Format, Arg1, Arg2, Arg3, Arg4) \
+do { \
+ char buf[4096]; \
+ sprintf (buf, Format, Arg1, Arg2, Arg3, Arg4); \
+ obstack_grow (Obs, buf, strlen (buf)); \
+} while (0)
+
+
+
+/*-----------------------------------------.
+| Extensions to use for the output files. |
+`-----------------------------------------*/
+
+#ifndef OUTPUT_EXT
+# define OUTPUT_EXT ".output"
+#endif
+
+#ifndef TAB_EXT
+# define TAB_EXT ".tab"