Remove direct call to srand(), just recommend the caller use it.

Instead of taking a seed argument, just treat `int randomized`
like a flag. (I'd use `bool`, but the header consistently uses
`int` for boolean arguments.)

include/fsm/walk.h

@@ -90,9 +90,10 @@ fsm_walk_edges(const struct fsm *fsm, void *opaque,
  * functionally equivalent cases makes testing dramatically faster,
  * but exploring every edge could be added later.
  *
- * If seed is zero then it will generate the first label in the label
- * set, otherwise a label from the set will be chosen using rand()
- * (favoring printable characters).
+ * If randomized is zero then it will generate the first label in the
+ * label set, otherwise a label from the set will be chosen using rand()
+ * (favoring printable characters). The caller can use srand()
+ * beforehand to set a PRNG seed.
  *
  * Note: fsm is non-const because it calls fsm_trim on the FSM
  * internally. This records the shortest distance from each state to an
@@ -118,7 +119,7 @@ fsm_generate_matches_cb(const struct fsm *fsm,
     const char *input, size_t input_length,
     fsm_state_t end_state, void *opaque);
 int
-fsm_generate_matches(struct fsm *fsm, size_t max_length, unsigned seed,
+fsm_generate_matches(struct fsm *fsm, size_t max_length, int randomized,
     fsm_generate_matches_cb *cb, void *opaque);
 
 /* Callback provided for the most basic use case for

src/libfsm/gen.c

@@ -107,7 +107,7 @@ struct gen_ctx {
 static bool
 gen_init_outer(struct fsm *fsm, size_t max_length,
     fsm_generate_matches_cb *cb, void *opaque,
-    bool randomized, unsigned seed);
+    bool randomized);
 
 static bool
 gen_init(struct gen_ctx *ctx, struct fsm *fsm);
@@ -140,7 +140,7 @@ static bool
 grow_stack(struct gen_ctx *ctx);
 
 int
-fsm_generate_matches(struct fsm *fsm, size_t max_length, unsigned seed,
+fsm_generate_matches(struct fsm *fsm, size_t max_length, int randomized,
     fsm_generate_matches_cb *cb, void *opaque)
 {
 	if (max_length == 0) {
@@ -154,7 +154,7 @@ fsm_generate_matches(struct fsm *fsm, size_t max_length, unsigned seed,
 
 	INIT_TIMERS();
 	TIME(&pre);
-	int res = gen_init_outer(fsm, max_length, cb, opaque, seed != 0, seed);
+	int res = gen_init_outer(fsm, max_length, cb, opaque, randomized != 0);
 	TIME(&post);
 
 	DIFF_MSEC("fsm_generate_matches", pre, post, NULL);
@@ -204,7 +204,7 @@ fsm_generate_cb_printf(const struct fsm *fsm,
 static bool
 gen_init_outer(struct fsm *fsm, size_t max_length,
     fsm_generate_matches_cb *cb, void *opaque,
-    bool randomized, unsigned seed)
+    bool randomized)
 {
 	int res = false;
 	if (fsm == NULL || cb == NULL || max_length == 0) {
@@ -213,10 +213,6 @@ gen_init_outer(struct fsm *fsm, size_t max_length,
 
 	assert(fsm_all(fsm, fsm_isdfa)); /* DFA-only */
 
-	if (randomized) {
-		srand(seed);
-	}
-
 #if LOG_GEN > 1
 	fprintf(stderr, "%s: %u states\n", __func__, fsm_countstates(fsm));
 #endif