Add test

testsuite/tests/typing-layouts/omitted_arguments.ml

@@ -0,0 +1,74 @@
+(* TEST
+ reference = "${test_source_directory}/omitted_arguments.reference";
+ include stdlib_upstream_compatible;
+ flambda2;
+ {
+   native;
+ } {
+   flags = "-Oclassic";
+   native;
+ } {
+   flags = "-O3";
+   native;
+ } {
+   bytecode;
+ }
+*)
+
+(* This is a test for applications where some arguments are omitted. We
+   previously had a bug where the layouts recorded in the eta-expansion the
+   compiler generates for such functions were incorrect. *)
+
+external box_float : float# -> float = "%box_float"
+external unbox_float : float -> float# = "%unbox_float"
+
+(* Omitting named arg *)
+let f1 ~name:x y = unbox_float (x +. y)
+
+let f2 (f : name:float -> float#) = f ~name:3.14
+
+let f3 () = f2 (f1 3.15)
+
+let _ =
+  Printf.printf "Omitting named arg (6.29): %.2f\n" (box_float (f3 ()))
+
+(* Omitting unnamed arg *)
+let f4 x ~name:y = unbox_float (x +. y)
+
+let f5 (f : float -> float#) = f 3.14
+
+let f6 () = f5 (f4 ~name:3.13)
+
+let _ =
+  Printf.printf "Omitting named arg (6.27): %.2f\n" (box_float (f6 ()))
+
+(* Omitting two named args*)
+let f7 ~name1 ~name2 x = unbox_float (name1 +. name2 +. x)
+
+let f8 (f : name1:float -> name2:float -> float#) = f ~name1:3.13 ~name2:3.15
+
+let f9 () = f8 (f7 3.14)
+
+let _ =
+  Printf.printf "Omitting named arg (9.42): %.2f\n" (box_float (f9 ()))
+
+(* Example adapted from real code *)
+
+let float_test : float# -> bool =
+  fun f -> Stdlib_upstream_compatible.Float_u.(equal f #3.0)
+let e : int -> size:int -> float# =
+  fun s ~size -> unbox_float (Float.of_int s +. Float.of_int size)
+
+let evaluate_1 () : 'a Array.t -> eval:local_ ('a -> float#) -> float# =
+  fun ts ~(local_ eval) ->
+    let eval i = eval (Array.get ts i) in
+    if float_test (eval 0) then #3.14 else #10.0
+
+let evaluate =
+  let evaluate_2 = evaluate_1 () in
+  fun t ~size ->
+    evaluate_2 t ~eval:(e ~size)
+
+let _ =
+  Printf.printf "\"real\" code (3.14): %.2f\n"
+    (box_float (evaluate [|2; 3; 4|] ~size:1))

testsuite/tests/typing-layouts/omitted_arguments.reference

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+Omitting named arg (6.29): 6.29
+Omitting named arg (6.27): 6.27
+Omitting named arg (9.42): 9.42
+"real" code (3.14): 3.14