From a16e66d338902e320f8acf1b34b3e37e1c5f001b Mon Sep 17 00:00:00 2001
From: "Sven M. Hallberg" <pesco@khjk.org>
Date: Thu, 13 Feb 2020 10:12:35 +0100
Subject: [PATCH] add an assert to h_follow()
---
src/cfgrammar.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/src/cfgrammar.c b/src/cfgrammar.c
index 77e7eca..1d80712 100644
--- a/src/cfgrammar.c
+++ b/src/cfgrammar.c
@@ -586,6 +586,7 @@ const HStringMap *h_follow(size_t k, HCFGrammar *g, const HCFChoice *x)
// iterate over g->nts
size_t i;
HHashTableEntry *hte;
+ int x_found=0;
for (i=0; i < g->nts->capacity; i++) {
for (hte = &g->nts->contents[i]; hte; hte = hte->next) {
if (hte->key == NULL) {
@@ -600,7 +601,8 @@ const HStringMap *h_follow(size_t k, HCFGrammar *g, const HCFChoice *x)
HCFChoice **s = (*p)->items; // production's right-hand side
for (; *s; s++) {
- if (*s == x) { // occurance found
+ if (*s == x) { // occurrence found
+ x_found=1;
HCFChoice **tail = s+1;
const HStringMap *first_tail = h_first_seq(k, g, tail);
@@ -612,6 +614,7 @@ const HStringMap *h_follow(size_t k, HCFGrammar *g, const HCFChoice *x)
}
}
}
+ assert(x_found || x == g->start); // no orphan non-terminals
return ret;
}
--
GitLab