From bbbaf1634cead71bd3997e062213bb63bd3ce544 Mon Sep 17 00:00:00 2001
From: "Sven M. Hallberg" <pesco@khjk.org>
Date: Fri, 21 Jun 2013 15:00:04 +0200
Subject: [PATCH] add an assertion checking that HLR_REDUCE is always followed
by HLR_SHIFT
---
src/backends/lr.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/src/backends/lr.c b/src/backends/lr.c
index 1ea6a395..2f7d5e48 100644
--- a/src/backends/lr.c
+++ b/src/backends/lr.c
@@ -314,6 +314,12 @@ bool h_lrengine_step(HLREngine *engine, const HLRAction *action)
// push result (value, symbol) onto the right stack
h_slist_push(right, value);
h_slist_push(right, symbol);
+
+ // this is LR, building a right-most derivation bottom-up, so no reduce can
+ // follow a reduce. we can also assume no conflict follows for GLR if we
+ // use LALR tables, because only terminal symbols (lookahead) get reduces.
+ const HLRAction *next = h_lr_lookup(engine->table, engine->state, symbol);
+ assert(next == NULL || next->type == HLR_SHIFT);
}
return true;
--
GitLab