Complain about arrays with length <= 0.

[r25035]

diff --git a/parser.c b/parser.c
index 40f2aeb..b364768 100644 (file)
--- a/parser.c
+++ b/parser.c
@@ -4684,9 +4684,20 @@ static type_t *construct_declarator_type(construct_type_t *construct_list, type_
 
                        if (size_expression != NULL) {
                                if (is_constant_expression(size_expression)) {
+                                       long const size                 = fold_constant(size_expression);
+                                       array_type->array.size          = size;
                                        array_type->array.size_constant = true;
-                                       array_type->array.size
-                                               = fold_constant(size_expression);
+                                       /* §6.7.5.2:1  If the expression is a constant expression, it shall
+                                        * have a value greater than zero. */
+                                       if (size <= 0) {
+                                               if (size < 0 || !GNU_MODE) {
+                                                       errorf(&size_expression->base.source_position,
+                                                                       "size of array must be greater than zero");
+                                               } else if (warning.other) {
+                                                       warningf(&size_expression->base.source_position,
+                                                                       "zero length arrays are a GCC extension");
+                                               }
+                                       }
                                } else {
                                        array_type->array.is_vla = true;
                                }