From: NeilBrown <neil@brown.name>
Date: Wed, 5 Jun 2019 08:09:59 +0000 (+1000)
Subject: parsergen - don't completely hide non-critical conflicts.
X-Git-Url: https://ocean-lang.org/code/?p=ocean;a=commitdiff_plain;h=f5e50e504ef5724ed7d9f13c411fff28d2b17a1e

parsergen - don't completely hide non-critical conflicts.

Shift/Reduce conflicts that are likely to be resolved by
a line break are currently hidden.  This is probably a good idea,
but sometimes it can be useful to see them anyway.
So report them as "non-critical" conflicts, and don't
count them - so if no other conflicts are found, the
"no conflicts" message is still generated.

Signed-off-by: NeilBrown <neil@brown.name>
---

diff --git a/csrc/parsergen.mdc b/csrc/parsergen.mdc
index a733035..2fdbf45 100644
--- a/csrc/parsergen.mdc
+++ b/csrc/parsergen.mdc
@@ -1776,10 +1776,10 @@ As a special case, if we find a SHIFT/REDUCE conflict, where a
 terminal that could be shifted is in the lookahead set of some
 reducable item, then set check if the reducable item also have
 `TK_newline` in its lookahead set.  If it does, then a newline will
-force and reduction, but anything else can reasonably be shifts, so
+force the reduction, but anything else can reasonably be shifted, so
 that isn't really a conflict.  Such apparent conflicts do not get
-reported.  This will not affect a "tradtional" grammar that does not
-include newlines as token.
+counted, and are reported as non-critical.  This will not affect a
+"traditional" grammar that does not include newlines as token.
 
 	static int conflicts_slr(struct grammar *g, enum grammar_type type)
 	{
@@ -1826,13 +1826,16 @@ include newlines as token.
 				int k;
 				for (k = 0; k < la.cnt; k++) {
 					int pos = symset_find(&shifts, la.syms[k]);
-					if (pos >= 0 && symset_find(&la, TK_newline) < 0) {
-						printf("  State %d has SHIFT/REDUCE conflict on ", i);
+					if (pos >= 0) {
+						if (symset_find(&la, TK_newline) < 0) {
+							printf("  State %d has SHIFT/REDUCE conflict on ", i);
+							cnt++;
+						} else
+							printf("  State %d has non-critical SHIFT/REDUCE conflict on ", i);
 						prtxt(g->symtab[la.syms[k]]->name);
 						printf(":\n");
 						report_item(g, shifts.data[pos]);
 						report_item(g, itm);
-						cnt++;
 					}
 					pos = symset_find(&reduce, la.syms[k]);
 					if (pos < 0) {