From 3bf56226d69538dce4b2dca0d5ca5fbc21e0a650 Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Fri, 25 May 2012 16:47:14 +0300
Subject: [PATCH] constraints: replace get_common_relationship() with
 get_shared_relations()

The get_common_relationship() was a crap API.  It was used to join to
lists so it should have taken lists as arguments.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
 smatch_constraints.c | 62 +++++++++++++++++++++++++++++++++++++++++-----------
 smatch_extra.c       |  9 ++------
 smatch_extra.h       |  4 ++--
 3 files changed, 53 insertions(+), 22 deletions(-)

diff --git a/smatch_constraints.c b/smatch_constraints.c
index 34e12085..badecaad 100644
--- a/smatch_constraints.c
+++ b/smatch_constraints.c
@@ -105,21 +105,57 @@ struct related_list *clone_related_list(struct related_list *related)
 	return to_list;
 }
 
-struct relation *get_common_relationship(struct smatch_state *state, int op,
-					const char *name, struct symbol *sym)
+static int cmp_relation(struct relation *a, struct relation *b)
 {
-	struct relation *tmp;
+	int ret;
 
-	// FIXME...
-	// Find the common x < y and x <= y
-	FOR_EACH_PTR(estate_related(state), tmp) {
-		if (tmp->op < op || tmp->sym < sym || strcmp(tmp->name, name) < 0)
-			continue;
-		if (tmp->op == op && tmp->sym == sym && !strcmp(tmp->name, name))
-			return tmp;
-		return NULL;
-	} END_FOR_EACH_PTR(tmp);
-	return NULL;
+	if (a == b)
+		return 0;
+
+	if (a->op > b->op)
+		return -1;
+	if (a->op < b->op)
+		return 1;
+
+	if (a->sym > b->sym)
+		return -1;
+	if (a->sym < b->sym)
+		return 1;
+
+	ret = strcmp(a->name, b->name);
+	if (ret)
+		return ret;
+
+	return 0;
+
+}
+
+struct related_list *get_shared_relations(struct related_list *one,
+					      struct related_list *two)
+{
+	struct related_list *ret = NULL;
+	struct relation *one_rel;
+	struct relation *two_rel;
+
+	PREPARE_PTR_LIST(one, one_rel);
+	PREPARE_PTR_LIST(two, two_rel);
+	for (;;) {
+		if (!one_rel || !two_rel)
+			break;
+		if (cmp_relation(one_rel, two_rel) < 0) {
+			NEXT_PTR_LIST(one_rel);
+		} else if (cmp_relation(one_rel, two_rel) == 0) {
+			add_ptr_list(&ret, one_rel);
+			NEXT_PTR_LIST(one_rel);
+			NEXT_PTR_LIST(two_rel);
+		} else {
+			NEXT_PTR_LIST(two_rel);
+		}
+	}
+	FINISH_PTR_LIST(two_rel);
+	FINISH_PTR_LIST(one_rel);
+
+	return ret;
 }
 
 static void debug_addition(struct smatch_state *state, int op, const char *name)
diff --git a/smatch_extra.c b/smatch_extra.c
index c3ce6f4d..cc45ead3 100644
--- a/smatch_extra.c
+++ b/smatch_extra.c
@@ -150,16 +150,11 @@ static struct smatch_state *merge_func(const char *name, struct symbol *sym,
 {
 	struct smatch_state *tmp;
 	struct range_list *value_ranges;
-	struct relation *rel;
-	struct relation *new;
 
 	value_ranges = range_list_union(estate_ranges(s1), estate_ranges(s2));
 	tmp = alloc_estate_range_list(value_ranges);
-	FOR_EACH_PTR(estate_related(s1), rel) {
-		new = get_common_relationship(s2, rel->op, rel->name, rel->sym);
-		if (new)
-			add_related(tmp, new->op, new->name, new->sym);
-	} END_FOR_EACH_PTR(rel);
+	get_dinfo(tmp)->related = get_shared_relations(estate_related(s1),
+						       estate_related(s2));
 	return tmp;
 }
 
diff --git a/smatch_extra.h b/smatch_extra.h
index f85d5852..aeda2ddd 100644
--- a/smatch_extra.h
+++ b/smatch_extra.h
@@ -110,8 +110,8 @@ struct expression *value_expr(long long val);
 
 /* implemented in smatch_constraints */
 void set_equiv(struct expression *left, struct expression *right);
-struct relation *get_common_relationship(struct smatch_state *estate, int op,
-					const char *name, struct symbol *sym);
+struct related_list *get_shared_relations(struct related_list *one,
+					      struct related_list *two);
 struct related_list *clone_related_list(struct related_list *related);
 void add_related(struct smatch_state *state, int op, const char *name, struct symbol *sym);
 void add_equiv(struct smatch_state *state, const char *name, struct symbol *sym);
-- 
2.11.4.GIT