Add tests for tail position info propagation

test/instrument/apply/operator.t

@@ -10,8 +10,9 @@ suppressed.
 Subexpressions instrumented recursively.
 
   $ bash ../test.sh <<'EOF'
-  > let _ = String.concat (String.trim "") @@ [];;
-  > let _ = (fun () -> ()) @@ ();;
+  > let _ = String.concat (String.trim "") @@ []
+  > let _ = (fun () -> ()) @@ ()
+  > let _ = String.concat "" @@ List.append [] []
   > EOF
   let _ =
     ___bisect_post_visit___ 1
@@ -23,3 +24,7 @@ Subexpressions instrumented recursively.
          ___bisect_visit___ 2;
          ())
       @@ ())
+
+  let _ =
+    ___bisect_post_visit___ 5
+      (String.concat "" @@ ___bisect_post_visit___ 4 (List.append [] []))

test/instrument/apply/pipe.t

@@ -28,3 +28,11 @@ Instrumentation suppressed in tail position.
    fun () ->
     ___bisect_visit___ 0;
     "" |> String.trim
+
+
+Right argument is not in tail position.
+
+  $ bash ../test.sh <<'EOF'
+  > let _ = [] |> List.mem 0
+  > EOF
+  let _ = ___bisect_post_visit___ 0 ([] |> List.mem 0)

test/instrument/control/for.t

@@ -58,3 +58,21 @@ Recursive instrumentation of subexpressions.
         ()
       done
     done
+
+
+Subexpressions not in tail position.
+
+  $ bash ../test.sh <<'EOF'
+  > let _ =
+  >   for _index = int_of_string "0" to int_of_string "1" do
+  >     print_endline "foo"
+  >   done
+  > EOF
+  let _ =
+    for
+      _index = ___bisect_post_visit___ 3 (int_of_string "0")
+      to ___bisect_post_visit___ 2 (int_of_string "1")
+    do
+      ___bisect_visit___ 1;
+      ___bisect_post_visit___ 0 (print_endline "foo")
+    done

test/instrument/control/fun.t

@@ -88,3 +88,21 @@ https://github.com/aantron/bisect_ppx/issues/319.
   let () =
     ignore
       (___bisect_post_visit___ 2 (List.map (___bisect_post_visit___ 1 (f ())) []))
+
+
+Expressions in default value are not in tail position; expressions in main
+subexpression are.
+
+  $ bash ../test.sh <<'EOF'
+  > [@@@ocaml.warning "-27"]
+  > let _ =
+  >   fun ?(l = print_endline "foo") () -> print_endline "bar"
+  > EOF
+  [@@@ocaml.warning "-27"]
+
+  let _ =
+   fun ?(l =
+         ___bisect_visit___ 1;
+         ___bisect_post_visit___ 0 (print_endline "foo")) () ->
+    ___bisect_visit___ 2;
+    print_endline "bar"

test/instrument/control/function.t

@@ -39,3 +39,14 @@ Instrumentation suppressed "between arguments."
     | () ->
         ___bisect_visit___ 0;
         ()
+
+
+Expressions in cases are in tail position.
+
+  $ bash ../test.sh <<'EOF'
+  > let _ = function () -> print_endline "foo"
+  > EOF
+  let _ = function
+    | () ->
+        ___bisect_visit___ 0;
+        print_endline "foo"

test/instrument/control/if.t

@@ -69,3 +69,31 @@ The next expression after if-then is instrumented as if it were an else-case.
       ());
     ___bisect_visit___ 0;
     ()
+
+
+Condition does not need its out-edge instrumented. Expressions in cases are in
+tail position iff the whole if-expression is in tail position.
+
+  $ bash ../test.sh <<'EOF'
+  > let _ =
+  >   if bool_of_string "true" then print_endline "foo" else print_endline "bar"
+  > let _ = fun () ->
+  >   if bool_of_string "true" then print_endline "foo" else print_endline "bar"
+  > EOF
+  let _ =
+    if bool_of_string "true" then (
+      ___bisect_visit___ 3;
+      ___bisect_post_visit___ 2 (print_endline "foo"))
+    else (
+      ___bisect_visit___ 1;
+      ___bisect_post_visit___ 0 (print_endline "bar"))
+
+  let _ =
+   fun () ->
+    ___bisect_visit___ 6;
+    if bool_of_string "true" then (
+      ___bisect_visit___ 5;
+      print_endline "foo")
+    else (
+      ___bisect_visit___ 4;
+      print_endline "bar")

test/instrument/control/lazy.t

@@ -20,3 +20,14 @@ Recursive instrumentation of subexpression.
        lazy
          (___bisect_visit___ 0;
           ()))
+
+
+Subexpression in tail position.
+
+  $ bash ../test.sh <<'EOF'
+  > let _ = lazy (print_endline "foo")
+  > EOF
+  let _ =
+    lazy
+      (___bisect_visit___ 0;
+       print_endline "foo")

test/instrument/control/match.t

@@ -41,3 +41,27 @@ Recursive instrumentation of cases.
         | () ->
             ___bisect_visit___ 0;
             ())
+
+
+Expressions in selector don't need their out-edge instrumented. Expressions in
+cases are in tail position iff the match expression is in tail position.
+
+  $ bash ../test.sh <<'EOF'
+  > let _ =
+  >   match print_endline "foo" with () -> print_endline "bar"
+  > let _ = fun () ->
+  >   match print_endline "foo" with () -> print_endline "bar"
+  > EOF
+  let _ =
+    match print_endline "foo" with
+    | () ->
+        ___bisect_visit___ 1;
+        ___bisect_post_visit___ 0 (print_endline "bar")
+
+  let _ =
+   fun () ->
+    ___bisect_visit___ 3;
+    match print_endline "foo" with
+    | () ->
+        ___bisect_visit___ 2;
+        print_endline "bar"

test/instrument/control/newtype.t

@@ -15,3 +15,19 @@ Recursive instrumentation of subexpression.
     fun (type _t) x ->
      ___bisect_visit___ 0;
      x
+
+
+Subexpression in tail position iff whole expression is in tail position.
+
+  $ bash ../test.sh <<'EOF'
+  > let _ =
+  >   fun (type _t) -> print_endline "foo"
+  > let _ = fun () ->
+  >   fun (type _t) -> print_endline "foo"
+  > EOF
+  let _ = fun (type _t) -> print_endline "foo"
+
+  let _ =
+   fun () ->
+    ___bisect_visit___ 0;
+    fun (type _t) -> print_endline "foo"

test/instrument/control/try.t

@@ -38,3 +38,27 @@ Recursive instrumentation of subexpressions.
       with _ ->
         ___bisect_visit___ 0;
         ())
+
+
+Main subexpression is not in tail position. Handler is in tail position iff the
+whole expression is in tail position.
+
+  $ bash ../test.sh <<'EOF'
+  > let _ =
+  >   try print_endline "foo" with _ -> print_endline "bar"
+  > let _ = fun () ->
+  >   try print_endline "foo" with _ -> print_endline "bar"
+  > EOF
+  let _ =
+    try ___bisect_post_visit___ 2 (print_endline "foo")
+    with _ ->
+      ___bisect_visit___ 1;
+      ___bisect_post_visit___ 0 (print_endline "bar")
+
+  let _ =
+   fun () ->
+    ___bisect_visit___ 5;
+    try ___bisect_post_visit___ 4 (print_endline "foo")
+    with _ ->
+      ___bisect_visit___ 3;
+      print_endline "bar"

test/instrument/control/while.t

@@ -34,3 +34,15 @@ Recursive instrumentation of subexpressions.
         ()
       done
     done
+
+
+Subexpressions not in tail position.
+
+  $ bash ../test.sh <<'EOF'
+  > let _ = while bool_of_string "true" do print_endline "foo" done
+  > EOF
+  let _ =
+    while ___bisect_post_visit___ 2 (bool_of_string "true") do
+      ___bisect_visit___ 1;
+      ___bisect_post_visit___ 0 (print_endline "foo")
+    done

test/instrument/recent/let-exception.t

@@ -1,9 +1,18 @@
   $ bash ../test.sh <<'EOF'
   > [@@@ocaml.warning "-38"]
-  > let _ = let exception E in print_endline "foo"
+  > let _ =
+  >   let exception E in print_endline "foo"
+  > let _ = fun () ->
+  >   let exception E in print_endline "foo"
   > EOF
   [@@@ocaml.warning "-38"]
 
   let _ =
     let exception E in
     ___bisect_post_visit___ 0 (print_endline "foo")
+
+  let _ =
+   fun () ->
+    ___bisect_visit___ 1;
+    let exception E in
+    print_endline "foo"

test/instrument/value.t

@@ -16,6 +16,7 @@ No instrumentation is inserted into expressions that are (syntactic) values.
   $ bash test.sh <<'EOF'
   > let _ = let x = 0 in x
   > let _ = let _x = print_endline "foo" in print_endline "bar"
+  > let _ = fun () -> let _x = print_endline "foo" in print_endline "bar"
   > EOF
   let _ =
     let x = 0 in
@@ -24,6 +25,12 @@ No instrumentation is inserted into expressions that are (syntactic) values.
   let _ =
     let _x = ___bisect_post_visit___ 1 (print_endline "foo") in
     ___bisect_post_visit___ 0 (print_endline "bar")
+
+  let _ =
+   fun () ->
+    ___bisect_visit___ 3;
+    let _x = ___bisect_post_visit___ 2 (print_endline "foo") in
+    print_endline "bar"
 
 
   $ bash test.sh <<'EOF'
@@ -141,6 +148,7 @@ No instrumentation is inserted into expressions that are (syntactic) values.
   $ bash test.sh <<'EOF'
   > let _ = (); 0
   > let _ = print_endline "foo"; print_endline "bar"
+  > let _ = fun () -> print_endline "foo"; print_endline "bar"
   > EOF
   let _ =
     ();
@@ -149,33 +157,54 @@ No instrumentation is inserted into expressions that are (syntactic) values.
   let _ =
     ___bisect_post_visit___ 1 (print_endline "foo");
     ___bisect_post_visit___ 0 (print_endline "bar")
+
+  let _ =
+   fun () ->
+    ___bisect_visit___ 3;
+    ___bisect_post_visit___ 2 (print_endline "foo");
+    print_endline "bar"
 
 
   $ bash test.sh <<'EOF'
   > let _ = (0 : int)
   > let _ = (print_endline "foo" : unit)
+  > let _ = fun () -> (print_endline "foo" : unit)
   > EOF
   let _ = (0 : int)
 
   let _ = (___bisect_post_visit___ 0 (print_endline "foo") : unit)
+
+  let _ =
+   fun () : unit ->
+    ___bisect_visit___ 1;
+    print_endline "foo"
 
 
   $ bash test.sh <<'EOF'
   > let _ = (`Foo :> [ `Foo | `Bar ])
-  > let _ = (`Foo (print_endline "foo") :> [ `Foo of unit | `Bar ])
+  > let f () = `Foo
+  > let _ = (f () :> [ `Foo | `Bar ])
+  > let _ = fun () -> (f () :> [ `Foo | `Bar ])
   > EOF
   let _ = (`Foo :> [ `Foo | `Bar ])
 
-  let _ =
-    (`Foo (___bisect_post_visit___ 0 (print_endline "foo"))
-      :> [ `Foo of unit | `Bar ])
+  let f () =
+    ___bisect_visit___ 0;
+    `Foo
+
+  let _ = (___bisect_post_visit___ 1 (f ()) :> [ `Foo | `Bar ])
+
+  let _ = fun () -> (f () :> [ `Foo | `Bar ])
 
 
   $ bash test.sh <<'EOF'
   > let _ = let module Foo = struct end in 0
   > let _ =
   >   let module Foo = struct let () = print_endline "foo" end in
   >   print_endline "bar"
+  > let _ = fun () ->
+  >   let module Foo = struct let () = print_endline "foo" end in
+  >   print_endline "bar"
   > EOF
   let _ =
     let module Foo = struct end in
@@ -186,6 +215,14 @@ No instrumentation is inserted into expressions that are (syntactic) values.
       let () = ___bisect_post_visit___ 1 (print_endline "foo")
     end in
     ___bisect_post_visit___ 0 (print_endline "bar")
+
+  let _ =
+   fun () ->
+    ___bisect_visit___ 3;
+    let module Foo = struct
+      let () = ___bisect_post_visit___ 2 (print_endline "foo")
+    end in
+    print_endline "bar"
 
 
   $ bash test.sh <<'EOF'
@@ -212,6 +249,7 @@ No instrumentation is inserted into expressions that are (syntactic) values.
   > [@@@ocaml.warning "-33"]
   > let _ = let open List in ignore
   > let _ = let open List in print_endline "foo"
+  > let _ = fun () -> let open List in print_endline "foo"
   > EOF
   [@@@ocaml.warning "-33"]
 
@@ -222,3 +260,9 @@ No instrumentation is inserted into expressions that are (syntactic) values.
   let _ =
     let open List in
     ___bisect_post_visit___ 0 (print_endline "foo")
+
+  let _ =
+   fun () ->
+    ___bisect_visit___ 1;
+    let open List in
+    print_endline "foo"