From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Wed, 28 May 2014 10:45:58 +0000 (+0300)
Subject: extra: more limits on which variables are equivalent
X-Git-Tag: 1.60~241
X-Git-Url: https://repo.or.cz/w/smatch.git/commitdiff_plain/72dc848f8a83d2af7d2c09e7c20f35e35e2dcaf8

extra: more limits on which variables are equivalent

If the assignment is:

	foo = &bar;

Then we don't record that as equivalent.  Unfortunately, I can't remember
why this is.  Probably it is because we don't record the state of &bar in
smatch_extra so they become out of sync.

If the assignment is:

	foo = foo->bar;

Then the problem is that after the assignment then the right side of the
assignment has changed so foo != foo->bar at the end.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---

diff --git a/smatch_extra.c b/smatch_extra.c
index f14c5be3..08dcb5da 100644
--- a/smatch_extra.c
+++ b/smatch_extra.c
@@ -514,8 +514,11 @@ static void match_vanilla_assign(struct expression *left, struct expression *rig
 	right_type = get_type(right);
 
 	right_name = expr_to_var_sym(right, &right_sym);
-	if (right_name && right_sym &&
-	    types_equiv_or_pointer(left_type, right_type)) {
+
+	if (!(right->type == EXPR_PREOP && right->op == '&') &&
+	    right_name && right_sym &&
+	    types_equiv_or_pointer(left_type, right_type) &&
+	    !has_symbol(right, sym)) {
 		set_equiv(left, right);
 		goto free;
 	}