re_strings: add support for endids.

This adds an extra parameter to `re_strings_add_str` and
`re_strings_add_raw` that (if non-NULL) will associate a single endid
with the string being added. When `re_strings_build` constructs the
DFA it will produce a separate end state for each end.

This needs further testing with multiple overlapping patterns. When
multiple literal strings appear in the input only the latest match
will be reported.

include/fsm/fsm.h

@@ -207,6 +207,12 @@ fsm_setend(struct fsm *fsm, fsm_state_t state, int end);
 int
 fsm_setendid(struct fsm *fsm, fsm_end_id_t id);
 
+/* Associate a numeric ID with a specific end state in an fsm.
+ * Returns 1 on success, 0 on error.
+ * */
+int
+fsm_setendidstate(struct fsm *fsm, fsm_state_t end_state, fsm_end_id_t id);
+
 /* Get the end IDs associated with an end state, if any.
  * If id_buf has enough cells to store all the end IDs (according
  * to id_buf_count) then they are written into id_buf[] and

include/re/strings.h

@@ -7,7 +7,7 @@
 #ifndef RE_STRINGS_H
 #define RE_STRINGS_H
 
-struct fsm;
+#include <fsm/fsm.h>
 struct fsm_options;
 
 struct re_strings;
@@ -42,10 +42,10 @@ void
 re_strings_free(struct re_strings *g);
 
 int
-re_strings_add_raw(struct re_strings *g, const void *p, size_t n);
+re_strings_add_raw(struct re_strings *g, const void *p, size_t n, const fsm_end_id_t *endid);
 
 int
-re_strings_add_str(struct re_strings *g, const char *s);
+re_strings_add_str(struct re_strings *g, const char *s, const fsm_end_id_t *endid);
 
 struct fsm *
 re_strings_build(struct re_strings *g,

src/libfsm/endids.c

@@ -84,6 +84,16 @@ fsm_setendid(struct fsm *fsm, fsm_end_id_t id)
 	return 1;
 }
 
+int
+fsm_setendidstate(struct fsm *fsm, fsm_state_t end_state, fsm_end_id_t id)
+{
+	enum fsm_endid_set_res sres = fsm_endid_set(fsm, end_state, id);
+	if (sres == FSM_ENDID_SET_ERROR_ALLOC_FAIL) {
+		return 0;
+	}
+	return 1;
+}
+
 enum fsm_getendids_res
 fsm_getendids(const struct fsm *fsm, fsm_state_t end_state,
     size_t id_buf_count, fsm_end_id_t *id_buf,

src/libfsm/libfsm.syms

@@ -89,6 +89,7 @@ fsm_getendids
 fsm_setendid
 fsm_mapendids
 fsm_increndids
+fsm_setendidstate
 
 fsm_countedges
 fsm_countstates

src/libre/ac.c

@@ -16,6 +16,7 @@
 
 #include "ac.h"
 
+#define ENDID_NONE ((fsm_end_id_t)-1)
 enum { POOL_BLOCK_SIZE = 256 };
 
 struct trie_state {
@@ -25,6 +26,7 @@ struct trie_state {
 	unsigned int index;
 	unsigned int output:1;
 	unsigned int have_st:1;
+	fsm_end_id_t endid;	/* or ENDID_NONE */
 };
 
 struct trie_pool {
@@ -126,7 +128,7 @@ trie_create(void)
 }
 
 struct trie_graph *
-trie_add_word(struct trie_graph *g, const char *w, size_t n)
+trie_add_word(struct trie_graph *g, const char *w, size_t n, const fsm_end_id_t *endid)
 {
 	struct trie_state *st;
 	size_t i;
@@ -159,6 +161,7 @@ trie_add_word(struct trie_graph *g, const char *w, size_t n)
 		g->depth = n;
 	}
 
+	st->endid = (endid == NULL ? ENDID_NONE : *endid);
 	return g;
 }
 
@@ -278,7 +281,7 @@ trie_to_fsm_state(struct trie_state *ts, struct fsm *fsm,
 	assert(fsm != NULL);
 	assert(q != NULL);
 
-	if (ts->output && have_end) {
+	if (ts->output && have_end && ts->endid == ENDID_NONE) {
 		*q = single_end;
 		return 1;
 	}
@@ -315,6 +318,11 @@ trie_to_fsm_state(struct trie_state *ts, struct fsm *fsm,
 
 	if (ts->output) {
 		fsm_setend(fsm, st, 1);
+		if (ts->endid != ENDID_NONE) {
+			if (!fsm_setendidstate(fsm, st, ts->endid)) {
+				return 0;
+			}
+		}
 	}
 
 	*q = st;

src/libre/ac.h

@@ -7,6 +7,8 @@
 #ifndef AC_H
 #define AC_H
 
+#include "fsm/fsm.h"
+
 struct fsm;
 struct fsm_state;
 struct fsm_options;
@@ -20,7 +22,8 @@ void
 trie_free(struct trie_graph *g);
 
 struct trie_graph *
-trie_add_word(struct trie_graph *g, const char *w, size_t n);
+trie_add_word(struct trie_graph *g, const char *w, size_t n,
+	const fsm_end_id_t *endid);
 
 int
 trie_add_failure_edges(struct trie_graph *g);

src/libre/re_strings.c

@@ -32,7 +32,7 @@ re_strings(const struct fsm_options *opt, const char *a[], size_t n,
 	}
 
 	for (i = 0; i < n; i++) {
-		if (!re_strings_add_str(g, a[i])) {
+		if (!re_strings_add_str(g, a[i], NULL)) {
 			goto error;
 		}
 	}
@@ -64,20 +64,20 @@ re_strings_free(struct re_strings *g)
 }
 
 int
-re_strings_add_raw(struct re_strings *g, const void *p, size_t n)
+re_strings_add_raw(struct re_strings *g, const void *p, size_t n, const fsm_end_id_t *endid)
 {
 	assert(p != NULL);
 	assert(n > 0);
 
-	return trie_add_word((struct trie_graph *) g, p, n) != NULL;
+	return trie_add_word((struct trie_graph *) g, p, n, endid) != NULL;
 }
 
 int
-re_strings_add_str(struct re_strings *g, const char *s)
+re_strings_add_str(struct re_strings *g, const char *s, const fsm_end_id_t *endid)
 {
 	assert(s != NULL);
 
-	return re_strings_add_raw(g, s, strlen(s));
+	return re_strings_add_raw(g, s, strlen(s), endid);
 }
 
 struct fsm *