naive list indexing with Mingyu

lib/irgen.ml

@@ -320,6 +320,16 @@ let rec build_expr expr (vars : variable StringMap.t) var_types the_module build
       list;
     llist
   | SStringLit s -> L.build_global_stringptr s "str" builder
+  | SIndex (list_expr, index_expr) ->
+    let list_val = build_expr list_expr vars var_types the_module builder in
+    let index_val = build_expr index_expr vars var_types the_module builder in
+    let elem_ptr = L.build_gep list_val [| index_val |] "elem_ptr" builder in
+
+    (match fst expr with
+     | RInt | RFloat | RBool | RChar | REnumType _ ->
+       L.build_load elem_ptr "elem_val" builder
+     | RUserType _ -> elem_ptr
+     | _ -> failwith "Unsupported list type for indexing")
   | e ->
     raise (Failure (Printf.sprintf "expr not implemented: %s" (Utils.string_of_sexpr e)))
 

test/ir/test_list.ml

@@ -98,6 +98,31 @@ let tests =
           in
           (* _write_to_file actual "actual.out"; *)
           assert_equal expected actual ~printer)
+       ; ("local_int_list_index"
+          >:: fun _ ->
+          let sast = get_sast "fun function() -> int {let a := [1, 2]; return a[0];}" in
+          let mdl = Irgen.translate sast in
+          let actual = L.string_of_llmodule mdl in
+          let expected =
+            "; ModuleID = 'Fly'\n\
+             source_filename = \"Fly\"\n\n\
+             define i32 @function() {\n\
+             entry:\n\
+            \  %list = alloca i32, i32 2, align 4\n\
+            \  %index = getelementptr inbounds i32, i32* %list, i32 0\n\
+            \  store i32 1, i32* %index, align 4\n\
+            \  %index1 = getelementptr inbounds i32, i32* %list, i32 1\n\
+            \  store i32 2, i32* %index1, align 4\n\
+            \  %a = alloca i32*, align 8\n\
+            \  store i32* %list, i32** %a, align 8\n\
+            \  %a2 = load i32*, i32** %a, align 8\n\
+            \  %elem_ptr = getelementptr i32, i32* %a2, i32 0\n\
+            \  %elem_val = load i32, i32* %elem_ptr, align 4\n\
+            \  ret i32 %elem_val\n\
+             }\n"
+          in
+          (* _write_to_file actual "actual.out"; *)
+          assert_equal expected actual ~printer)
        ]
 ;;