+
+/*----------------------------------------------------------------.
+| Compute BASE_NAME, SHORT_BASE_NAME and output files extensions. |
+`----------------------------------------------------------------*/
+
+/* Replace all characters FROM by TO in the string IN.
+ and returns a new allocated string. */
+static char *
+tr (const char *in, char from, char to)
+{
+ char *temp;
+ char *out;
+
+ out = XMALLOC (char, strlen (in) + 1);
+
+ for (temp = out; *in; in++, out++)
+ if (*in == from)
+ *out = to;
+ else
+ *out = *in;
+ *out = 0;
+ return (temp);
+}
+
+/* Gets the extension index in FILENAME. Returns 0 if fails to
+ find an extension. */
+static int
+get_extension_index (const char *filename)
+{
+ int len;
+
+ len = strlen (filename);
+
+ if (filename[len-- - 1] == '.')
+ return (0);
+
+ while ((len > 0) && (filename[len - 1] != '.'))
+ if (filename[len - 1] == '/')
+ return (0);
+ else
+ len--;
+
+ return (len - 1);
+}
+
+/* Computes extensions from the grammar file extension. */
+static void
+compute_exts_from_gf (const char *ext)
+{
+ /* Checks if SRC_EXTENSION is NULL. In the other case, %source_extension
+ was specified in the grammar file. */
+ if (src_extension == NULL)
+ {
+ src_extension = tr (ext, 'y', 'c');
+ src_extension = tr (src_extension, 'Y', 'C');
+ }
+ /* Checks if HEADER_EXTENSION is NULL. In the other case,
+ %header_extension was specified in the grammar file. */
+ if (header_extension == NULL)
+ {
+ header_extension = tr (ext, 'y', 'h');
+ header_extension = tr (header_extension, 'Y', 'H');
+ }
+}
+
+/* Computes extensions from the given c source file extension. */
+static void
+compute_exts_from_src (const char *ext)
+{
+ /* We use this function when the user specifies `-o' or `--output',
+ so the extenions must be computed unconditionally from the file name
+ given by this option. */
+ src_extension = xstrdup (ext);
+ header_extension = tr (ext, 'c', 'h');
+ header_extension = tr (header_extension, 'C', 'H');
+}