Handle enum types in array accessors

Closes #227

Author: steeve

src/Translator.zig

@@ -3138,7 +3138,7 @@ fn transArrayAccess(t: *Translator, scope: *Scope, array_access: Node.ArrayAcces
     const index = index: {
         const index = try t.transExpr(scope, array_access.index, .used);
         const index_qt = array_access.index.qt(t.tree);
-        const maybe_bigger_than_usize = switch (index_qt.base(t.comp).type) {
+        const maybe_bigger_than_usize = type: switch (index_qt.base(t.comp).type) {
             .bool => {
                 break :index try ZigTag.int_from_bool.create(t.arena, index);
             },
@@ -3147,6 +3147,7 @@ fn transArrayAccess(t: *Translator, scope: *Scope, array_access: Node.ArrayAcces
                 else => false,
             },
             .bit_int => |bit_int| bit_int.bits > t.comp.target.ptrBitWidth(),
+            .@"enum" => |e| if (e.tag) |tag| continue :type tag.base(t.comp).type else false,
             else => unreachable,
         };
 

test/cases/translate/array_access_with_enum.c

@@ -0,0 +1,29 @@
+typedef enum {
+    one = 1,
+    two = 2,
+} EnumValues;
+
+static inline int dynamic_array_access(EnumValues idx) {
+  static const int values[] = {0, 1, 2};
+  return values[idx - 1];
+}
+
+// translate
+// target=native-linux
+//
+// pub const one: c_int = 1;
+// pub const two: c_int = 2;
+// pub const EnumValues = c_uint;
+// pub fn dynamic_array_access(arg_idx: EnumValues) callconv(.c) c_int {
+//     var idx = arg_idx;
+//     _ = &idx;
+//     const static_local_values = struct {
+//         const values: [3]c_int = [3]c_int{
+//             0,
+//             1,
+//             2,
+//         };
+//     };
+//     _ = &static_local_values;
+//     return static_local_values.values[idx -% @as(EnumValues, 1)];
+// }