Use the new structured errors (#10170) for better error messages

.depend

@@ -667,13 +667,15 @@ typing/includeclass.cmo : \
     typing/types.cmi \
     typing/printtyp.cmi \
     typing/path.cmi \
+    typing/errortrace.cmi \
     typing/ctype.cmi \
     parsing/builtin_attributes.cmi \
     typing/includeclass.cmi
 typing/includeclass.cmx : \
     typing/types.cmx \
     typing/printtyp.cmx \
     typing/path.cmx \
+    typing/errortrace.cmx \
     typing/ctype.cmx \
     parsing/builtin_attributes.cmx \
     typing/includeclass.cmi
@@ -689,6 +691,7 @@ typing/includecore.cmo : \
     typing/printtyp.cmi \
     typing/primitive.cmi \
     typing/path.cmi \
+    utils/misc.cmi \
     typing/ident.cmi \
     typing/errortrace.cmi \
     typing/env.cmi \
@@ -704,6 +707,7 @@ typing/includecore.cmx : \
     typing/printtyp.cmx \
     typing/primitive.cmx \
     typing/path.cmx \
+    utils/misc.cmx \
     typing/ident.cmx \
     typing/errortrace.cmx \
     typing/env.cmx \

testsuite/tests/printing-types/disambiguation.ml

@@ -9,14 +9,16 @@ Error: Type declarations do not match:
          type !'a x = private [> `x ] constraint 'a = 'a x
        is not included in
          type 'a x
-       Their constraints differ.
+       Their parameters differ
+       The type 'b x as 'b is not equal to the type 'a
 |}, Principal{|
 Line 1:
 Error: Type declarations do not match:
          type !'a x = private 'a constraint 'a = [> `x ]
        is not included in
          type 'a x
-       Their constraints differ.
+       Their parameters differ
+       The type [> `x ] is not equal to the type 'a
 |}];;
 
 

testsuite/tests/typing-extensions/extensions.ml

@@ -322,9 +322,9 @@ Error: Signature mismatch:
          type ('a, 'b) bar += A of int
        Constructors do not match:
          A of float
-       is not compatible with:
+       is not the same as:
          A of int
-       The types are not equal.
+       The type float is not equal to the type int
 |}]
 
 module M : sig
@@ -348,9 +348,9 @@ Error: Signature mismatch:
          type ('a, 'b) bar += A of 'a
        Constructors do not match:
          A of 'b
-       is not compatible with:
+       is not the same as:
          A of 'a
-       The types are not equal.
+       The type 'b is not equal to the type 'a
 |}]
 
 module M : sig
@@ -374,9 +374,9 @@ Error: Signature mismatch:
          type ('a, 'b) bar = A of 'a
        Constructors do not match:
          A of 'a
-       is not compatible with:
+       is not the same as:
          A of 'a
-       The types are not equal.
+       The type 'a is not equal to the type 'b
 |}];;
 
 
@@ -401,9 +401,9 @@ Error: Signature mismatch:
          type ('a, 'b) bar += A : 'c -> ('c, 'd) bar
        Constructors do not match:
          A : 'd -> ('c, 'd) bar
-       is not compatible with:
+       is not the same as:
          A : 'c -> ('c, 'd) bar
-       The types are not equal.
+       The type 'd is not equal to the type 'c
 |}]
 
 (* Extensions can be rebound *)

testsuite/tests/typing-extensions/open_types.ml

@@ -117,7 +117,8 @@ Line 1, characters 0-37:
     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 Error: This variant or record definition does not match that of type
          ('a, 'a) foo
-       Their constraints differ.
+       Their parameters differ
+       The type 'a is not equal to the type 'b
 |}]
 
 (* Check that signatures can hide exstensibility *)

testsuite/tests/typing-gadts/ambiguity.ml

@@ -233,6 +233,9 @@ Error: Signature mismatch:
          val r : '_weak1 list ref
        is not included in
          val r : T.u list ref
+       The type 'weak1 list ref is not compatible with the type T.u list ref
+       This instance of T.u is ambiguous:
+       it would escape the scope of its equation
 |}]
 
 module M = struct
@@ -264,4 +267,7 @@ Error: Signature mismatch:
          val r : '_weak2 list ref
        is not included in
          val r : T.t list ref
+       The type 'weak2 list ref is not compatible with the type T.t list ref
+       This instance of T.t is ambiguous:
+       it would escape the scope of its equation
 |}]

testsuite/tests/typing-gadts/pr7160.ml

@@ -20,7 +20,8 @@ Lines 4-5, characters 0-77:
 Error: This variant or record definition does not match that of type 'a t
        Constructors do not match:
          Same : 'l t -> 'l t
-       is not compatible with:
+       is not the same as:
          Same : 'l1 t -> 'l2 t
-       The types are not equal.
+       The type 'l t is not equal to the type 'l1 t
+       Type 'l is not equal to type 'l1
 |}];;

testsuite/tests/typing-gadts/pr7378.ml

@@ -21,9 +21,10 @@ Lines 2-3, characters 2-37:
 Error: This variant or record definition does not match that of type X.t
        Constructors do not match:
          A : 'a * 'b * ('a -> unit) -> X.t
-       is not compatible with:
+       is not the same as:
          A : 'a * 'b * ('b -> unit) -> X.t
-       The types are not equal.
+       The type 'a -> unit is not equal to the type 'b -> unit
+       Type 'a is not equal to type 'b
 |}]
 
 (* would segfault

testsuite/tests/typing-misc/deep.ml

@@ -21,6 +21,8 @@ Error: Signature mismatch:
          val x : bool * string
        is not included in
          val x : bool * int
+       The type bool * string is not compatible with the type bool * int
+       Type string is not compatible with type int
 |}]
 
 module T : sig
@@ -42,6 +44,9 @@ Error: Signature mismatch:
          val f : int -> int
        is not included in
          val f : int -> (float * string ref) list
+       The type int -> int is not compatible with the type
+         int -> (float * string ref) list
+       Type int is not compatible with type (float * string ref) list
 |}]
 
 (* Alpha-equivalence *)
@@ -64,6 +69,9 @@ Error: Signature mismatch:
          val f : 'c list * 'd ref -> int
        is not included in
          val f : 'a list * 'b list -> int
+       The type 'a list * 'b ref -> int is not compatible with the type
+         'a list * 'c list -> int
+       Type 'b ref is not compatible with type 'c list
 |}]
 
 module T : sig
@@ -85,4 +93,6 @@ Error: Signature mismatch:
          type t = bool * float
        is not included in
          type t = int * float
+       The type bool * float is not equal to the type int * float
+       Type bool is not equal to type int
 |}]

testsuite/tests/typing-misc/enrich_typedecl.ml

@@ -31,6 +31,7 @@ Error: Signature mismatch:
          type t = A.t = A | B
        is not included in
          type t = int * string
+       The type A.t is not equal to the type int * string
 |}]
 
 module rec B : sig
@@ -62,6 +63,7 @@ Error: Signature mismatch:
          type 'a t = 'a B.t = A of 'a | B
        is not included in
          type 'a t = 'a
+       The type 'a B.t is not equal to the type 'a
 |}];;
 
 module rec C : sig
@@ -126,6 +128,7 @@ Error: Signature mismatch:
          type 'a t = 'a D.t = A of 'a | B
        is not included in
          type 'a t = int
+       The type 'a D.t is not equal to the type int
 |}];;
 
 module rec E : sig
@@ -157,6 +160,7 @@ Error: Signature mismatch:
          type 'a t = 'a E.t = A of 'a | B
        is not included in
          type 'a t = 'a constraint 'a = [> `Foo ]
+       The type 'a is not equal to the type [> `Foo ]
 |}];;
 
 module rec E2 : sig
@@ -188,6 +192,7 @@ Error: Signature mismatch:
          type 'a t = 'a E2.t = A of 'a | B
        is not included in
          type 'a t = [ `Foo ]
+       The type 'a E2.t is not equal to the type [ `Foo ]
 |}];;
 
 module rec E3 : sig
@@ -219,6 +224,7 @@ Error: Signature mismatch:
          type 'a t = 'a E3.t = A of 'a | B
        is not included in
          type 'a t = 'a constraint 'a = [< `Foo ]
+       The type 'a is not equal to the type [< `Foo ]
 |}];;
 
 
@@ -254,7 +260,7 @@ Error: Signature mismatch:
          type ('a, 'b) t = Foo of 'a
        Constructors do not match:
          Foo of 'b
-       is not compatible with:
+       is not the same as:
          Foo of 'a
-       The types are not equal.
+       The type 'b is not equal to the type 'a
 |}];;

testsuite/tests/typing-misc/pr6416.ml

@@ -26,6 +26,8 @@ Error: Signature mismatch:
          val f : t/1 -> unit
        is not included in
          val f : t/2 -> unit
+       The type t/1 -> unit is not compatible with the type t/2 -> unit
+       Type t/1 is not compatible with type t/2
        Line 6, characters 4-14:
          Definition of type t/1
        Line 2, characters 2-12:
@@ -52,9 +54,9 @@ Error: Signature mismatch:
          type u = A of t/2
        Constructors do not match:
          A of t/1
-       is not compatible with:
+       is not the same as:
          A of t/2
-       The types are not equal.
+       The type t/1 is not equal to the type t/2
        Line 4, characters 9-19:
          Definition of type t/1
        Line 2, characters 2-11:
@@ -121,9 +123,9 @@ Error: Signature mismatch:
          type t = A of T/2.t
        Constructors do not match:
          A of T/1.t
-       is not compatible with:
+       is not the same as:
          A of T/2.t
-       The types are not equal.
+       The type T/1.t is not equal to the type T/2.t
        Line 5, characters 6-34:
          Definition of module T/1
        Line 2, characters 2-30:
@@ -150,6 +152,9 @@ Error: Signature mismatch:
          val f : (module s/1) -> t/2 -> t/1
        is not included in
          val f : (module s/2) -> t/2 -> t/2
+       The type (module s/1) -> t/2 -> t/1 is not compatible with the type
+         (module s/2) -> t/2 -> t/2
+       Type (module s/1) is not compatible with type (module s/2)
        Line 5, characters 23-33:
          Definition of type t/1
        Line 3, characters 2-12:
@@ -180,6 +185,9 @@ Error: Signature mismatch:
          val f : a/2 -> 'a -> a/1
        is not included in
          val f : a/2 -> (module a) -> a/2
+       The type a/2 -> (module a) -> a/1 is not compatible with the type
+         a/2 -> (module a) -> a/2
+       Type a/1 is not compatible with type a/2
        Line 5, characters 12-22:
          Definition of type a/1
        Line 3, characters 2-12:
@@ -333,6 +341,7 @@ Error: Signature mismatch:
          type a = M/1.t
        is not included in
          type a = M/2.t
+       The type M/1.t is not equal to the type M/2.t
        Line 2, characters 14-42:
          Definition of module M/1
        File "_none_", line 1:
@@ -366,6 +375,9 @@ Error: Signature mismatch:
          val f : t/2 -> t/3 -> t/4 -> t/1
        is not included in
          val f : t/1 -> t/1 -> t/1 -> t/1
+       The type t/2 -> t/3 -> t/4 -> t/1 is not compatible with the type
+         t/1 -> t/1 -> t/1 -> t/1
+       Type t/2 is not compatible with type t/1
        Line 4, characters 0-10:
          Definition of type t/1
        Line 1, characters 0-10:

testsuite/tests/typing-misc/pr6634.ml

@@ -23,8 +23,10 @@ Error: Signature mismatch:
          type t = [ `T of t/2 ]
        is not included in
          type t = [ `T of t/1 ]
-       Line 1, characters 0-12:
-         Definition of type t/1
+       The type [ `T of t/1 ] is not equal to the type [ `T of t/2 ]
+       Types for tag `T are incompatible
        Line 4, characters 2-20:
+         Definition of type t/1
+       Line 1, characters 0-12:
          Definition of type t/2
 |}]

testsuite/tests/typing-misc/pr7668_bad.ml

@@ -89,4 +89,9 @@ Error: Signature mismatch:
            [> `B of [> `BA | `BB of int list ] | `C of unit ]
        is not included in
          val a : t -> t
+       The type
+         [ `A of int | `B of [ `BA | `BB of unit list ] | `C of unit ] ->
+         [> `B of [> `BA | `BB of int list ] | `C of unit ]
+       is not compatible with the type t -> t
+       Types for tag `BB are incompatible
 |}]

testsuite/tests/typing-misc/records.ml

@@ -198,7 +198,8 @@ Line 1, characters 0-40:
     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 Error: This variant or record definition does not match that of type
          (int, [> `A ]) def
-       Their constraints differ.
+       Their parameters differ
+       The type int is not equal to the type 'a
 |}]
 
 type ('a,'b) kind = ('a, 'b) def = A constraint 'b = [> `A];;
@@ -221,7 +222,7 @@ Line 2, characters 0-37:
 Error: This variant or record definition does not match that of type d
        Fields do not match:
          y : int;
-       is not compatible with:
+       is not the same as:
          mutable y : int;
        This is mutable and the original is not.
 |}]
@@ -243,9 +244,9 @@ Line 1, characters 0-31:
 Error: This variant or record definition does not match that of type d
        Fields do not match:
          x : int;
-       is not compatible with:
+       is not the same as:
          x : float;
-       The types are not equal.
+       The type int is not equal to the type float
 |}]
 
 type unboxed = d = {x:float} [@@unboxed]