[pfff] add support for parsing :: inside type expressions

Summary:
Diff 1/2 for adding typeconst support. This makes it possible to refer
to types of the form `MyClass::my_named_tconst`.

There are some AST changes here, so propagate those through as well.

Test Plan:
  make tests # doesn't break anything

Diff 2/2 will add some testcases that exercise both tconst definitions
and tconst usages.

Reviewers: dominik, dreeves

Reviewed By: dreeves

Subscribers: dominik

Differential Revision: https://phabricator.fb.com/D1880752

Tasks: 6358822

Signature: t1:1880752:1425321719:ad278426e6f78cd6ccc611e1b5c4cc84f3e78aba

lang_php/analyze/foundation/ast_php_simple.ml

@@ -307,6 +307,7 @@ and hint_type =
  | HintTuple of hint_type list
  | HintCallback of hint_type list * (hint_type option)
  | HintShape of (string_const_expr * hint_type) list
+ | HintTypeConst of (hint_type * hint_type)
 
 and class_name = hint_type
 

lang_php/analyze/foundation/ast_php_simple_build.ml

@@ -473,6 +473,8 @@ and hint_type env = function
       xs +> brace +> comma_list +> List.map (fun (e, _tok, t) ->
         expr env e, hint_type env t
       ))
+  | HintTypeConst (lhs, _tok, rhs) ->
+    A.HintTypeConst (hint_type env lhs, hint_type env rhs)
 
 (* ------------------------------------------------------------------------- *)
 (* Definitions *)

lang_php/analyze/foundation/database_prolog_php.ml

@@ -94,6 +94,7 @@ let rec string_of_hint_type x =
     "(" ^ (String.concat ", " elts) ^ ")"
   | HintCallback _ -> "callback"
   | HintShape _ -> "shape"
+  | HintTypeConst _ -> "typeconst"
 
 let string_of_hint_type_opt h =
   match h with

lang_php/analyze/foundation/dependencies_toposort_php.ml

@@ -185,6 +185,10 @@ module Deps = struct
     | HintShape xs ->
       List.fold_left (fun accp (_s,x) ->
         SSet.union accp (hint_type_ accp x)) acc xs
+    | HintTypeConst (x1, x2) ->
+      List.fold_left (fun accp x ->
+        SSet.union accp (hint_type_ accp x)) acc [x1; x2]
+
 
 
   and class_def acc c =

lang_php/analyze/foundation/graph_code_php.ml

@@ -875,6 +875,9 @@ and hint_type env t =
     xs +> List.iter (fun (_ket, t) ->
       hint_type env t
     )
+  | HintTypeConst (x1, x2) ->
+    hint_type env x1;
+    hint_type env x2
 
 (* ---------------------------------------------------------------------- *)
 (* Expr *)

lang_php/analyze/foundation/meta_ast_php_simple.ml

@@ -348,6 +348,10 @@ and vof_hint_type =
              in Ocaml.VTuple [ v1; v2 ])
           v1
       in Ocaml.VSum (("HintShape", [ v1 ]))
+  | HintTypeConst (v1, v2) ->
+    let v1 = vof_hint_type v1
+    and v2 = vof_hint_type v2
+    in Ocaml.VSum (("HintTypeConst", [ v1; v2]))
 
 and
   vof_class_def {

lang_php/analyze/foundation/typing_php.ml

@@ -785,6 +785,7 @@ and parameter env p =
     | Some (HintTuple _)
     | Some (HintCallback _) -> Tvar (fresh())
     | Some (HintShape _) -> failwith "no support for shape yet"
+    | Some (HintTypeConst _) -> failwith "no support for type consts"
   in
   (match p.p_default with
   | None -> ()

lang_php/analyze/visual/highlight_php.ml

@@ -593,6 +593,7 @@ let visit_program ~tag _prefs  hentities (ast, toks) =
       | HintCallback _
         (* todo: colorize as record the keys? *)
       | HintShape _
+      | HintTypeConst _
         ->
         ()
       );

lang_php/matcher/php_vs_php.ml

@@ -2486,14 +2486,21 @@ and m_hint_type a b =
       return (A.HintShape(a1, a2),
               B.HintShape(b1, b2)
       )))
-
+  | A.HintTypeConst(a1, a2, a3), B.HintTypeConst(b1, b2, b3) ->
+    m_hint_type a1 b1 >>= (fun (a1, b1) ->
+    m_tok a2 b2 >>= (fun (a2, b2) ->
+    m_hint_type a3 b3 >>= (fun (a3, b3) ->
+      return (A.HintTypeConst(a1, a2, a3),
+              B.HintTypeConst(b1, b2, b3)
+      ))))
 
   | A.Hint _, _
   | A.HintArray _, _
   | A.HintQuestion _, _
   | A.HintTuple _, _
   | A.HintCallback _, _
   | A.HintShape _, _
+  | A.HintTypeConst _, _ 
    -> fail ()
 and m_hint_type_ret (a1, a2, a3) (b1, b2, b3) =
   m_tok a1 b1 >>= (fun (a1, b1) ->

lang_php/matcher/refactoring_code_php.ml

@@ -101,15 +101,17 @@ let refactor refactorings (ast, tokens) =
               (match p.p_type with
               | None -> ()
               | Some x ->
-                  let tok =
+                let rec leftmost_tok x =
                     match x with
                     | HintArray tok -> tok
                     | Hint (name, _typeargs) -> Ast.info_of_name name
                     | HintQuestion (tok, _t) -> tok
                     | HintTuple (t, _, _) -> t
                     | HintCallback (lparen,_,_) -> lparen
                     | HintShape (tok, _) -> tok
-                  in
+                    | HintTypeConst (hint, _, _) -> leftmost_tok hint
+                in
+                let tok = leftmost_tok x in
                   if tok_pos_equal_refactor_pos tok pos_opt then begin
                     tok.PI.transfo <-
                       PI.AddBefore (PI.AddStr ("?"));

lang_php/parsing/ast_php.ml

@@ -144,11 +144,15 @@ type hint_type =
  | HintCallback of
      (tok                                 (* "function" *)
       * (hint_type comma_list_dots paren) (* params *)
-      * (tok * tok option * hint_type) option          (* return type *)
+      * (tok * tok option * hint_type) option (* return type *)
      ) paren
  | HintShape of
      tok (* "shape" *) *
      (string_const_expr * tok (* '=>' *) * hint_type) comma_list paren
+ | HintTypeConst of
+     hint_type   (* lhs *)
+     * tok       (* '::' *)
+     * hint_type (* rhs *)
 
  and type_args = hint_type comma_list single_angle
 

lang_php/parsing/map_php.ml

@@ -829,6 +829,11 @@ and map_hint_type =
                 in (v1, v2, v3)))
           v2
       in HintShape ((v1, v2))
+  | HintTypeConst ((v1, v2, v3)) ->
+      let v1 = map_hint_type v1
+      and v2 = map_tok v2
+      and v3 = map_hint_type v3
+      in HintTypeConst ((v1, v2, v3))
 
 and map_is_ref v = map_of_option map_tok v
 and map_lambda_def (v1, v2) =

lang_php/parsing/meta_ast_php.ml

@@ -860,6 +860,12 @@ and vof_hint_type =
                 in Ocaml.VTuple [ v1; v2; v3 ]))
           v2
       in Ocaml.VSum (("HintShape", [ v1; v2 ]))
+  | HintTypeConst ((v1, v2, v3)) ->
+      let v1 = vof_hint_type v1
+      and v2 = vof_tok v2
+      and v3 = vof_hint_type v3
+      in Ocaml.VSum (("HintTypeConst", [ v1; v2; v3]))
+
 
 and vof_is_ref v = vof_option vof_tok v
 

lang_php/parsing/parser_php.mly

@@ -934,6 +934,11 @@ variance_opt:
 /*(*************************************************************************)*/
 
 type_php:
+ | primary_type_php { $1 }
+/*(*facebook-ext: classes can define type constants referenced using `::`*)*/
+ | type_php TCOLCOL primary_type_php { HintTypeConst ($1, $2, $3) }
+
+primary_type_php:
  | class_name { $1 }
  | T_SELF     { Hint (Self $1, None) }
  | T_PARENT   { Hint (Parent $1, None) }
@@ -945,6 +950,7 @@ type_php:
  | TOPAR T_FUNCTION TOPAR type_php_or_dots_list TCPAR return_type TCPAR
      { HintCallback ($1, ($2, ($3, $4, $5), Some $6), $7)}
 
+
 /*(* similar to parameter_list, but without names for the parameters *)*/
 type_php_or_dots_list:
  | /*(*empty*)*/                     { [] }

lang_php/parsing/visitor_php.ml

@@ -873,9 +873,16 @@ and v_hint_type x =
                 in ()))
           v2
       in ()
+  | HintTypeConst ((v1, v2, v3)) ->
+      let v1 = v_hint_type v1
+      and v2 = v_tok v2
+      and v3 = v_hint_type v3
+      in ()
   in
   vin.khint_type (k, all_functions) x
 
+
+
 and v_is_ref v = v_option v_tok v
 
 and v_constraint (v1, v2) =

lang_php/pretty/ast_pp_build.ml

@@ -620,8 +620,9 @@ and hint_type env = function
     in
     A.HintCallback (args, ret)
   | HintShape _ ->
-    failwith "no support shape"
-
+    failwith "no support for shape"
+  | HintTypeConst _ ->
+    failwith "no support for type consts"
 
 and class_name_reference env a = expr env a