From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Tue, 9 Oct 2012 11:23:49 +0000 (+0300)
Subject: type: improve handling of type promotion on binary operations
X-Git-Tag: 1.57~215
X-Git-Url: https://repo.or.cz/w/smatch.git/commitdiff_plain/e1a94b5687b78e6b906b37639e16647ae6024e56

type: improve handling of type promotion on binary operations

Arrays are handled specially.  If both types are smaller than ints then it
returns an int.  If they are larger it returns the one which is largest.

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

diff --git a/smatch_type.c b/smatch_type.c
index f1306802..1de6073f 100644
--- a/smatch_type.c
+++ b/smatch_type.c
@@ -24,6 +24,30 @@ struct symbol *get_real_base_type(struct symbol *sym)
 	return ret;
 }
 
+static struct symbol *get_binop_type(struct expression *expr)
+{
+	struct symbol *left, *right;
+
+	left = get_type(expr->left);
+	right = get_type(expr->right);
+
+	if (left && (left->type == SYM_PTR || left->type == SYM_ARRAY))
+		return left;
+	if (right && (right->type == SYM_PTR || right->type == SYM_ARRAY))
+		return right;
+
+	if (!left || !right)
+		return NULL;
+
+	if (type_max(left) < type_max(&int_ctype) &&
+	    type_max(right) < type_max(&int_ctype))
+		return &int_ctype;
+
+	if (type_max(right) > type_max(left))
+		return right;
+	return left;
+}
+
 static struct symbol *get_type_symbol(struct expression *expr)
 {
 	if (!expr || expr->type != EXPR_SYMBOL || !expr->symbol)
@@ -92,8 +116,6 @@ static struct symbol *fake_pointer_sym(struct expression *expr)
 
 struct symbol *get_type(struct expression *expr)
 {
-	struct symbol *tmp;
-
 	if (!expr)
 		return NULL;
 	expr = strip_parens(expr);
@@ -114,10 +136,7 @@ struct symbol *get_type(struct expression *expr)
 	case EXPR_IMPLIED_CAST:
 		return get_real_base_type(expr->cast_type);
 	case EXPR_BINOP:
-		if (expr->op != '+')
-			return NULL;
-		tmp = get_type(expr->left);
-		return tmp;
+		return get_binop_type(expr);
 	case EXPR_CALL:
 		return get_return_type(expr);
 	case EXPR_SIZEOF: