From: Sven Verdoolaege <skimo@kotnet.org>
Date: Thu, 15 Sep 2011 12:25:51 +0000 (+0200)
Subject: isl_stream_next_token: treat "-0" as two tokens '-' and '0'
X-Git-Tag: isl-0.08~78
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=77119eba7479e6352d22a3ce991d48b6ad0884bc;hp=56b7d238929980e62218525b4b3be121af386edf;p=platform%2Fupstream%2Fisl.git

isl_stream_next_token: treat "-0" as two tokens '-' and '0'

Usually, a '-' followed by a sequence of digits is treated as a single
(negative) number.  When parsing affine expressions, negative numbers
are allowed without a preceding '+'.  However, if "-0" is parsed as '0'
then there is no way of distinguishing between "-0" and "0" and so "-0"
was not allowed in affine expressions.
We now treat "-0" as two tokens, so that it can be used in affine expressions.
The flip side is that "-0" can no longer be used where a single integer
is expected.

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>
---

diff --git a/isl_stream.c b/isl_stream.c
index 01a2caa..3643893 100644
--- a/isl_stream.c
+++ b/isl_stream.c
@@ -391,6 +391,7 @@ static struct isl_token *next_token(struct isl_stream *s, int same_line)
 		}
 	}
 	if (c == '-' || isdigit(c)) {
+		int minus = c == '-';
 		tok = isl_token_new(s->ctx, line, col, old_line != line);
 		if (!tok)
 			return NULL;
@@ -405,6 +406,15 @@ static struct isl_token *next_token(struct isl_stream *s, int same_line)
 			isl_stream_ungetc(s, c);
 		isl_stream_push_char(s, '\0');
 		isl_int_read(tok->u.v, s->buffer);
+		if (minus && isl_int_is_zero(tok->u.v)) {
+			tok->col++;
+			tok->on_new_line = 0;
+			isl_stream_push_token(s, tok);
+			tok = isl_token_new(s->ctx, line, col, old_line != line);
+			if (!tok)
+				return NULL;
+			tok->type = (enum isl_token_type) '-';
+		}
 		return tok;
 	}
 	if (isalpha(c) || c == '_') {
diff --git a/isl_test.c b/isl_test.c
index 075650a..a0173b3 100644
--- a/isl_test.c
+++ b/isl_test.c
@@ -140,6 +140,10 @@ void test_parse(struct isl_ctx *ctx)
 	str2 = "[N, M] -> { [i] : N = 2 and 4i <= 2 + M and 4i >= -1 + M }";
 	test_parse_map_equal(ctx, str, str2);
 
+	str = "{ [x] : x >= 0 }";
+	str2 = "{ [x] : x-0 >= 0 }";
+	test_parse_map_equal(ctx, str, str2);
+
 	test_parse_pwqp(ctx, "{ [i] -> i + [ (i + [i/3])/2 ] }");
 	test_parse_map(ctx, "{ S1[i] -> [([i/10]),i%10] : 0 <= i <= 45 }");
 }