From 54e838f482844369048d4f88e87a092a87162b72 Mon Sep 17 00:00:00 2001
From: Siraaj Khandkar <siraaj@khandkar.net>
Date: Mon, 17 Sep 2018 07:59:10 -0400
Subject: [PATCH] Fix - check number of arguments in function calls

---
 compiler/src/lib/tiger/tiger_error.ml         | 22 +++++++++++++++++++
 compiler/src/lib/tiger/tiger_error.mli        |  1 +
 compiler/src/lib/tiger/tiger_semant.ml        | 18 +++++++++++----
 .../src/lib/tiger/tiger_test_cases_book.ml    |  4 ++++
 4 files changed, 41 insertions(+), 4 deletions(-)

diff --git a/compiler/src/lib/tiger/tiger_error.ml b/compiler/src/lib/tiger/tiger_error.ml
index e1b0736..88096a2 100644
--- a/compiler/src/lib/tiger/tiger_error.ml
+++ b/compiler/src/lib/tiger/tiger_error.ml
@@ -214,6 +214,28 @@ let is_wrong_type t =
   | Different_operand_types _ ->
       false
 
+let is_wrong_number_of_args t =
+  match t with
+  | Wrong_number_of_args _ ->
+      true
+  | Wrong_type _
+  | Unknown_type _
+  | Unknown_id _
+  | Invalid_syntax _
+  | Id_is_a_function _
+  | Id_not_a_function _
+  | No_such_field_in_record _
+  | Exp_not_a_record _
+  | Exp_not_an_array _
+  | Wrong_type_of_expression_in_var_dec _
+  | Wrong_type_used_as_array _
+  | Wrong_type_used_as_record _
+  | Wrong_type_of_field_value _
+  | Wrong_type_of_arg _
+  | Invalid_operand_type _
+  | Different_operand_types _ ->
+      false
+
 let is_invalid_syntax t =
   match t with
   | Invalid_syntax _ ->
diff --git a/compiler/src/lib/tiger/tiger_error.mli b/compiler/src/lib/tiger/tiger_error.mli
index d7c2e79..9090ad4 100644
--- a/compiler/src/lib/tiger/tiger_error.mli
+++ b/compiler/src/lib/tiger/tiger_error.mli
@@ -73,6 +73,7 @@ val to_string : t -> string
 val is_unknown_id   : t -> bool
 val is_unknown_type : t -> bool
 val is_wrong_type   : t -> bool
+val is_wrong_number_of_args : t -> bool
 val is_invalid_syntax : t -> bool
 val is_not_a_record : t -> bool
 val is_not_an_array : t -> bool
diff --git a/compiler/src/lib/tiger/tiger_semant.ml b/compiler/src/lib/tiger/tiger_semant.ml
index 8d0ca11..a3893fa 100644
--- a/compiler/src/lib/tiger/tiger_semant.ml
+++ b/compiler/src/lib/tiger/tiger_semant.ml
@@ -90,10 +90,20 @@ end = struct
       | A.CallExp {func; args; pos} ->
           (match env_get_val ~sym:func ~env ~pos with
           | Value.Fun {formals; result} ->
-              List.iter2 formals args ~f:(fun ty_expected exp_given ->
-                check_same (return (actual_ty ~pos ty_expected)) (trexp exp_given) ~pos;
-              );
-              return (actual_ty ~pos result)
+              let expected = List.length formals in
+              let given    = List.length args in
+              if given = expected then
+                begin
+                  List.iter2 formals args ~f:(fun ty_expected exp_given ->
+                    check_same
+                      (return (actual_ty ~pos ty_expected))
+                      (trexp exp_given)
+                      ~pos;
+                  );
+                  return (actual_ty ~pos result)
+                end
+              else
+                E.raise (E.Wrong_number_of_args {func; expected; given; pos})
           | Value.Var _ ->
               E.raise (E.Id_not_a_function {id=func; pos})
           )
diff --git a/compiler/src/lib/tiger/tiger_test_cases_book.ml b/compiler/src/lib/tiger/tiger_test_cases_book.ml
index 7502b47..76bb5af 100644
--- a/compiler/src/lib/tiger/tiger_test_cases_book.ml
+++ b/compiler/src/lib/tiger/tiger_test_cases_book.ml
@@ -113,6 +113,10 @@ let is_error_expected_semant_of_filename =
   | "test25.tig" ->
       Some Error.is_not_a_record
       (* TODO: Be more specific *)
+  | "test35.tig"
+  | "test36.tig" ->
+      Some Error.is_wrong_number_of_args
+      (* TODO: Be more specific - how many expected, how many given? *)
   | "test09.tig"
   | "test11.tig"
   | "test13.tig"
-- 
2.20.1