From caac8a86d23d6d058a4234e265c2f50e7e7c9b84 Mon Sep 17 00:00:00 2001
From: NeilBrown <neil@brown.name>
Date: Wed, 24 Feb 2021 19:57:08 +1100
Subject: [PATCH] parsergen: do not create empty goto arrays

These empty arrays are a waste of space ...  assuming they take up
any(?).

Using NULL is more ideomatic.

Signed-off-by: NeilBrown <neil@brown.name>
---
 csrc/parsergen.mdc | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/csrc/parsergen.mdc b/csrc/parsergen.mdc
index a6486df..5d2e164 100644
--- a/csrc/parsergen.mdc
+++ b/csrc/parsergen.mdc
@@ -2065,10 +2065,13 @@ The go to table is stored in a simple array of `sym` and corresponding
 		int i;
 		fprintf(f, "#line 0 \"gen_goto\"\n");
 		for (i = 0; i < g->states; i++) {
+			struct symset gt = g->statetab[i]->go_to;
 			int j;
+
+			if (gt.cnt == 0)
+				continue;
 			fprintf(f, "static const struct lookup goto_%d[] = {\n",
 				i);
-			struct symset gt = g->statetab[i]->go_to;
 			for (j = 0; j < gt.cnt; j++)
 				fprintf(f, "\t{ %d, %d },\n",
 					gt.syms[j], gt.data[j]);
@@ -2099,18 +2102,21 @@ The go to table is stored in a simple array of `sym` and corresponding
 					prod_len = pr->body_size;
 				}
 			}
-
-			if (prod >= 0)
-				fprintf(f, "\t[%d] = { %d, goto_%d, %d, %d, %d, %d, %d, %d },\n",
-					i, is->go_to.cnt, i, prod,
-					g->productions[prod]->body_size,
-					g->productions[prod]->head->num,
+			if (is->go_to.cnt)
+				fprintf(f, "\t[%d] = { %d, goto_%d, ",
+				        i, is->go_to.cnt, i);
+			else
+				fprintf(f, "\t[%d] = { 0, NULL, ", i);
+			if (prod >= 0) {
+				struct production *pr = g->productions[prod];
+				fprintf(f, "%d, %d, %d, %d, %d, %d },\n", prod,
+					pr->body_size,
+					pr->head->num,
 					is->starts_line,
-					g->productions[prod]->line_like,
+					pr->line_like,
 					is->min_prefix);
-			else
-				fprintf(f, "\t[%d] = { %d, goto_%d, -1, -1, -1, %d, 0, %d },\n",
-					i, is->go_to.cnt, i,
+			} else
+				fprintf(f, "-1, -1, -1, %d, 0, %d },\n",
 					is->starts_line, is->min_prefix);
 		}
 		fprintf(f, "};\n\n");
-- 
2.43.0