+/*----- Configuration parsing ---------------------------------------------*/
+
+/* --- @parse@ --- *
+ *
+ * Arguments: @scanner *sc@ = pointer to scanner definition
+ *
+ * Returns: ---
+ *
+ * Use: Parses a configuration file from the scanner.
+ */
+
+static source_ops *sources[] =
+ { &xsource_ops, &fsource_ops, &ssource_ops, 0 };
+static target_ops *targets[] =
+ { &xtarget_ops, &ftarget_ops, &starget_ops, 0 };
+
+void parse(scanner *sc)
+{
+ token(sc);
+
+ for (;;) {
+ if (sc->t == CTOK_EOF)
+ break;
+ if (sc->t != CTOK_WORD)
+ error(sc, "parse error, keyword expected");
+
+ /* --- Handle a forwarding request --- */
+
+ if (strcmp(sc->d.buf, "forward") == 0 ||
+ strcmp(sc->d.buf, "fw") == 0 ||
+ strcmp(sc->d.buf, "from") == 0) {
+ source *s;
+ target *t;
+
+ token(sc);
+
+ /* --- Read a source description --- */
+
+ {
+ source_ops **sops;
+
+ /* --- Try to find a source type which understands --- */
+
+ s = 0;
+ for (sops = sources; *sops; sops++) {
+ if ((s = (*sops)->read(sc)) != 0)
+ goto found_source;
+ }
+ error(sc, "unknown source name `%s'", sc->d.buf);
+
+ /* --- Read any source-specific options --- */
+
+ found_source:
+ if (sc->t == '{') {
+ token(sc);
+ while (sc->t == CTOK_WORD) {
+ if (!s->ops->option || !s->ops->option(s, sc)) {
+ error(sc, "unknown %s source option `%s'",
+ s->ops->name, sc->d.buf);
+ }
+ if (sc->t == ';')
+ token(sc);
+ }
+ if (sc->t != '}')
+ error(sc, "parse error, missing `}'");
+ token(sc);
+ }
+ }
+
+ /* --- Read a destination description --- */
+
+ if (sc->t == CTOK_WORD && (strcmp(sc->d.buf, "to") == 0 ||
+ strcmp(sc->d.buf, "->") == 0))
+ token(sc);
+
+ {
+ target_ops **tops;
+
+ /* --- Try to find a target which understands --- */
+
+ t = 0;
+ for (tops = targets; *tops; tops++) {
+ if ((t = (*tops)->read(sc)) != 0)
+ goto found_target;
+ }
+ error(sc, "unknown target name `%s'", sc->d.buf);
+
+ /* --- Read any target-specific options --- */
+
+ found_target:
+ if (sc->t == '{') {
+ token(sc);
+ while (sc->t == CTOK_WORD) {
+ if (!t->ops->option || !t->ops->option(t, sc)) {
+ error(sc, "unknown %s target option `%s'",
+ t->ops->name, sc->d.buf);
+ }
+ if (sc->t == ';')
+ token(sc);
+ }
+ if (sc->t != '}')
+ error(sc, "parse error, `}' expected");
+ token(sc);
+ }
+ }
+
+ /* --- Combine the source and target --- */
+
+ s->ops->attach(s, sc, t);
+ }
+
+ /* --- Include configuration from a file --- *
+ *
+ * Slightly tricky. Scan the optional semicolon from the including
+ * stream, not the included one.
+ */
+
+ else if (strcmp(sc->d.buf, "include") == 0) {
+ FILE *fp;
+ dstr d = DSTR_INIT;
+
+ token(sc);
+ conf_name(sc, '/', &d);
+ if ((fp = fopen(d.buf, "r")) == 0)
+ error(sc, "can't include `%s': %s", d.buf, strerror(errno));
+ if (sc->t == ';')
+ token(sc);
+ pushback(sc);
+ scan_push(sc, scan_file(fp, d.buf, 0));
+ token(sc);
+ dstr_destroy(&d);
+ continue; /* Don't parse a trailing `;' */
+ }
+
+ /* --- Other configuration is handled elsewhere --- */
+
+ else {
+
+ /* --- First try among the sources --- */
+
+ {
+ source_ops **sops;
+
+ for (sops = sources; *sops; sops++) {
+ if ((*sops)->option && (*sops)->option(0, sc))
+ goto found_option;
+ }
+ }
+
+ /* --- Then try among the targets --- */
+
+ {
+ target_ops **tops;
+
+ for (tops = targets; *tops; tops++) {
+ if ((*tops)->option && (*tops)->option(0, sc))
+ goto found_option;
+ }
+ }
+
+ /* --- Nobody wants the option --- */
+
+ error(sc, "unknown global option or prefix `%s'", sc->d.buf);
+
+ found_option:;
+ }
+
+ if (sc->t == ';')
+ token(sc);
+ }
+}
+
+/*----- General utility functions -----------------------------------------*/