Disallow slicing of constant values

1 files changed, 10 insertions, 3 deletions

diff --git a/src/check_expr.cpp b/src/check_expr.cpp
index 51dad8f79..18f210b63 100644
--- a/src/check_expr.cpp
+++ b/src/check_expr.cpp
@@ -7811,10 +7811,7 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 			return kind;
 		}
 
-		o->mode = Addressing_Value;
-
 		if (se->low == nullptr && se->high != nullptr) {
-			// error(se->interval0, "1st index is required if a 2nd index is specified");
 			// It is okay to continue as it will assume the 1st index is zero
 		}
 
@@ -7849,6 +7846,16 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 			}
 		}
 
+		if (max_count < 0)  {
+			if (o->mode == Addressing_Constant) {
+				gbString s = expr_to_string(se->expr);
+				error(se->expr, "Cannot slice constant value '%s'", s);
+				gb_string_free(s);
+			}
+		}
+
+		o->mode = Addressing_Value;
+
 		if (is_type_string(t) && max_count >= 0) {
 			bool all_constant = true;
 			for (isize i = 0; i < gb_count_of(nodes); i++) {