- struct grep_expr *header_expr = NULL;
-
- if (opt->header_list) {
- p = opt->header_list;
- header_expr = compile_pattern_expr(&p);
- if (p)
- die("incomplete pattern expression: %s", p->pattern);
- for (p = opt->header_list; p; p = p->next) {
- switch (p->token) {
- case GREP_PATTERN: /* atom */
- case GREP_PATTERN_HEAD:
- case GREP_PATTERN_BODY:
- compile_regexp(p, opt);
- break;
- default:
- opt->extended = 1;
- break;
- }
+ struct grep_expr *header_expr;
+ struct grep_expr *(header_group[GREP_HEADER_FIELD_MAX]);
+ enum grep_header_field fld;
+
+ if (!opt->header_list)
+ return NULL;
+ p = opt->header_list;
+ for (p = opt->header_list; p; p = p->next) {
+ if (p->token != GREP_PATTERN_HEAD)
+ die("bug: a non-header pattern in grep header list.");
+ if (p->field < 0 || GREP_HEADER_FIELD_MAX <= p->field)
+ die("bug: unknown header field %d", p->field);
+ compile_regexp(p, opt);
+ }
+
+ for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++)
+ header_group[fld] = NULL;
+
+ for (p = opt->header_list; p; p = p->next) {
+ struct grep_expr *h;
+ struct grep_pat *pp = p;
+
+ h = compile_pattern_atom(&pp);
+ if (!h || pp != p->next)
+ die("bug: malformed header expr");
+ if (!header_group[p->field]) {
+ header_group[p->field] = h;
+ continue;