constexpr: recognize address constants created through pointer arithmetic

An address constant +/- an integer constant expression qualifies as an
address constant again.
Furthermore, the array-subscript operator "[]" may be used in the creation
of address constant.

Handle both cases by making evaluate_ptr_add() check whether an integer
constant expression is added to an address constant and tag the result as
being an address constant again if so.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/evaluate.c b/evaluate.c
index ce2e52e1..e58d9c37 100644
--- a/evaluate.c
+++ b/evaluate.c
@@ -571,6 +571,13 @@ static struct symbol *evaluate_ptr_add(struct expression *expr, struct symbol *i
 	classify_type(degenerate(expr->left), &ctype);
 	base = examine_pointer_target(ctype);
 
+	/*
+	 * An address constant +/- an integer constant expression
+	 * yields an address constant again [6.6(7)].
+	 */
+	if ((expr->left->flags & CEF_ADDR) && (expr->right->flags & CEF_ICE))
+		expr->flags = CEF_ADDR;
+
 	if (!base) {
 		expression_error(expr, "missing type information");
 		return NULL;