Temporarily re-add static locals

Summary: This is meant for 4.2, not 4.1

Reviewed By: alexeyt

Differential Revision: D14525623

fbshipit-source-id: 02c576127292e04c982f40a158306ad2d6139697

hphp/doc/bytecode.specification

@@ -3670,6 +3670,33 @@ FuncNumArgs   []   ->   [C:Int]
 
   Push the number of arguments the current function was called with.
 
+StaticLocCheck  <local variable id> <litstr id> []  ->  [C:Bool]
+
+  Static variable. This instruction first checks if the static variable named
+  %2 has been marked as initialized. If the static variable has been marked as
+  initialized, this instruction binds the static variable to the local variable
+  %1 and pushes true. Otherwise, this instruction pushes false.
+
+StaticLocDef <local variable id> <litstr id>        [C]  ->  []
+
+  Initialize static variable. This instruction binds the static variable to
+  the local variable, assigns $1 to the local variable, and marks the static
+  variable as initialized.
+
+  Precondition: Except in memoized functions, the static local named %2 has
+  not been initialized
+
+StaticLocInit <local variable id> <litstr id>    [C]  ->  []
+
+  Static variable with initializer. This instruction first checks if the static
+  variable named %2 has been marked as initialized. If the static variable has
+  been marked as initialized, this instruction binds the static variable to the
+  local variable %1. Otherwise, this instruction binds the static variable to
+  the local variable, assigns $1 to the local variable, and marks the static
+  variable as initialized.
+
+  The cell in $1 must not be a reference counted type.
+
 Catch    []  ->  [C:Obj]
 
   Catch. Retrieves the current exception object and pushes it onto the stack.

hphp/doc/ir.specification

@@ -1523,6 +1523,16 @@ To string conversions:
 
   Load the length of the string in S0.
 
+| LdClosureStaticLoc<func,staticLocalName>, D(PtrToPropGen), S(Obj), NF
+
+  Get pointer to static local named 'staticLocName' for function 'func' whose
+  closure object is S0. func must either be a Closure, or generatorFromClosure
+
+| LdStaticLoc<func,staticLocalName>, D(BoxedInitCell), NA, PRc
+
+  Load the address of the static local variable named 'staticLocalName' for
+  function 'func' in RDS. The variable must be initialized
+
 | FuncSupportsAsyncEagerReturn, D(Bool), S(Func), NF
 
   Tests for Func::m_attrs & AttrSupportsAsyncEagerReturn.
@@ -2296,6 +2306,16 @@ To string conversions:
   Raises a runtime error unless whether each generic in S0 is reified or erased
   matches exactly to the expectations of the func.
 
+| CheckStaticLoc<func,staticLocalName>, ND, NA, B
+
+  Check whether the static local variable named 'staticLocalName' for
+  function 'func' is initialized in RDS, and branch if not.
+
+| InitStaticLoc<func,staticLocalName>, ND, S(Cell), NF
+
+  Initialize the static local variable named 'staticLocalName' for
+  function 'func' with S0.
+
 | InitClsCns<className,constName>, DCns, NA, PRc
 
   Initialize the RDS entry for a constant for a class, invoking autoload if it

hphp/hack/src/annotated_ast/aast.ml

@@ -72,6 +72,7 @@ and stmt_ =
   | Return of expr option
   | GotoLabel of pstring
   | Goto of pstring
+  | Static_var of expr list
   | Global_var of expr list
   | Awaitall of (lid option * expr) list
   | If of expr * block * block

hphp/hack/src/annotated_ast/aast_mapper.ml

@@ -239,6 +239,7 @@ struct
     | S.Return oe -> T.Return (Option.map oe (map_expr menv))
     | S.GotoLabel label -> T.GotoLabel label
     | S.Goto label -> T.Goto label
+    | S.Static_var el -> T.Static_var (map_exprl menv el)
     | S.Global_var el -> T.Global_var (map_exprl menv el)
     | S.Awaitall el ->
       let el = List.map el (fun (lid, expr) -> (lid, map_expr menv expr)) in

hphp/hack/src/facts/flatten_smart_constructors.ml

@@ -267,6 +267,12 @@ module WithOp(Op : Op_S) = struct
   let make_continue_statement arg0 arg1 arg2 state =
     if Op.is_zero arg0 && Op.is_zero arg1 && Op.is_zero arg2 then state, Op.zero
     else state, Op.flatten [arg0; arg1; arg2]
+  let make_function_static_statement arg0 arg1 arg2 state =
+    if Op.is_zero arg0 && Op.is_zero arg1 && Op.is_zero arg2 then state, Op.zero
+    else state, Op.flatten [arg0; arg1; arg2]
+  let make_static_declarator arg0 arg1 state =
+    if Op.is_zero arg0 && Op.is_zero arg1 then state, Op.zero
+    else state, Op.flatten [arg0; arg1]
   let make_echo_statement arg0 arg1 arg2 state =
     if Op.is_zero arg0 && Op.is_zero arg1 && Op.is_zero arg2 then state, Op.zero
     else state, Op.flatten [arg0; arg1; arg2]

hphp/hack/src/hackfmt/hack_format.ml

@@ -157,6 +157,7 @@ let rec t (env: Env.t) (node: Syntax.t) : Doc.t =
   | Syntax.PipeVariableExpression _
   | Syntax.PropertyDeclarator _
   | Syntax.ConstantDeclarator _
+  | Syntax.StaticDeclarator _
   | Syntax.ScopeResolutionExpression _
   | Syntax.EmbeddedMemberSelectionExpression _
   | Syntax.EmbeddedSubscriptExpression _
@@ -1236,6 +1237,11 @@ let rec t (env: Env.t) (node: Syntax.t) : Doc.t =
       continue_level = level;
       continue_semicolon = semi; } ->
     transform_keyword_expression_statement env kw level semi
+  | Syntax.FunctionStaticStatement {
+      static_static_keyword = static_kw;
+      static_declarations = declarators;
+      static_semicolon = semi; } ->
+    transform_keyword_expr_list_statement env static_kw declarators semi
   | Syntax.EchoStatement {
       echo_keyword = kw;
       echo_expressions = expr_list;

hphp/hack/src/hh_single_compile.ml

@@ -429,6 +429,7 @@ let make_popt () =
     ~enable_await_as_an_expression:(enable_await_as_an_expression co)
     ~disable_nontoplevel_declarations:(phpism_disable_nontoplevel_declarations co)
     ~disable_static_closures:(phpism_disable_static_closures co)
+    ~disable_static_local_variables:(phpism_disable_static_local_variables co)
     ~enable_hh_syntax_for_hhvm:(enable_hiphop_syntax co)
     ~enable_stronger_await_binding:(enable_stronger_await_binding co)
     ~disable_lval_as_an_expression:(disable_lval_as_an_expression co)

hphp/hack/src/hhbc/closure_convert.ml

@@ -88,6 +88,9 @@ type state = {
   inout_wrappers : fun_ list;
   (* The current namespace environment *)
   namespace: Namespace_env.env;
+  (* Static variables in closures have special properties with mangled names
+   * defined for them *)
+  static_vars : ULS.t;
   (* Set of closure names that used to have explicit 'use' language construct
     in original anonymous function *)
   explicit_use_set: SSet.t;
@@ -140,6 +143,7 @@ let initial_state popt =
   named_hoisted_functions = SMap.empty;
   inout_wrappers = [];
   namespace = Namespace_env.empty popt;
+  static_vars = ULS.empty;
   explicit_use_set = SSet.empty;
   closure_namespaces = SMap.empty;
   closure_enclosing_classes = SMap.empty;
@@ -368,8 +372,12 @@ let enter_lambda st =
     captured_vars = ULS.empty;
     captured_this = false;
     captured_generics = ULS.empty;
+    static_vars = ULS.empty;
    }
 
+let add_static_var st var =
+  { st with static_vars = ULS.add st.static_vars var }
+
 let set_namespace st ns =
   { st with namespace = ns }
 
@@ -433,6 +441,9 @@ let make_closure ~class_num
   let cvl =
     List.map lambda_vars
     (fun name -> (p, (p, Hhbc_string_utils.Locals.strip_dollar name), None)) in
+  let cvl = cvl @ (List.map (ULS.items st.static_vars)
+    (fun name -> (p, (p,
+     "86static_" ^ (Hhbc_string_utils.Locals.strip_dollar name)), None))) in
   let cd = {
     c_mode = fd.f_mode;
     c_user_attributes = [];
@@ -878,6 +889,7 @@ and convert_lambda env st p fd use_vars_opt =
   let captured_vars = st.captured_vars in
   let captured_this = st.captured_this in
   let captured_generics = st.captured_generics in
+  let static_vars = st.static_vars in
   let old_function_state = st.current_function_state in
   let st = enter_lambda st in
   let old_env = env in
@@ -970,6 +982,7 @@ and convert_lambda env st p fd use_vars_opt =
   let st = { st with captured_vars;
                      captured_this;
                      captured_generics;
+                     static_vars;
                      explicit_use_set;
                      closure_enclosing_classes;
                      closure_namespaces = SMap.add
@@ -1014,6 +1027,16 @@ and convert_stmt env st (p, stmt_ as stmt) : _ * stmt =
   | Return opt_e ->
     let st, opt_e = convert_opt_expr env st opt_e in
     st, (p, Return opt_e)
+  | Static_var el ->
+    let visit_static_var st e =
+      begin match snd e with
+      | Lvar (_, name)
+      | Binop (Eq None, (_, Lvar (_, name)), _) -> add_static_var st name
+      | _ -> failwith "Static var - impossible"
+      end in
+    let st = List.fold_left el ~init:st ~f:visit_static_var in
+    let st, el = convert_exprs env st el in
+    st, (p, Static_var el)
   | Awaitall el ->
     let st, el = List.map_env st el (convert_snd_expr env) in
     st, (p, Awaitall el)

hphp/hack/src/hhbc/emit_body.ml

@@ -134,7 +134,7 @@ and emit_defs env defs =
 
 let make_body body_instrs decl_vars
               is_memoize_wrapper is_memoize_wrapper_lsb
-              params return_type_info doc_comment
+              params return_type_info static_inits doc_comment
               env =
   let body_instrs = rewrite_user_labels body_instrs in
   let body_instrs = rewrite_class_refs body_instrs in
@@ -154,6 +154,7 @@ let make_body body_instrs decl_vars
     is_memoize_wrapper_lsb
     params
     return_type_info
+    static_inits
     doc_comment
     env
 
@@ -332,6 +333,10 @@ let emit_body
     then remove_this vars @ ["$this"]
     else vars in
 
+  let starts_with s prefix =
+    String.length s >= String.length prefix &&
+    String.sub s 0 (String.length prefix) = prefix in
+
   let has_this = Ast_scope.Scope.has_this scope in
   let is_toplevel = Ast_scope.Scope.is_toplevel scope in
   (* see comment in decl_vars.ml, method on_efun of declvar_visitor
@@ -360,7 +365,9 @@ let emit_body
         |> List.concat_map ~f:(fun item ->
           match item with
           | Ast.ClassVars { Ast.cv_names = cvl; _ } ->
-            List.map cvl ~f:(fun (_, (_, id), _) -> ("$" ^ id))
+            List.filter_map cvl ~f:(fun (_, (_, id), _) ->
+              if not (starts_with id "86static_")
+              then Some ("$" ^ id) else None)
           | _ -> []) in
       "$0Closure" ::
       captured_vars @
@@ -418,6 +425,15 @@ let emit_body
   let generator_instr =
     if is_generator then gather [instr_createcont; instr_popc] else empty
   in
+  let svar_map = Static_var.make_static_map body in
+  let emit_expr env e =
+    gather [
+      Emit_expression.emit_expr env ~need_ref:false e;
+      Emit_pos.emit_pos (fst e)
+    ] in
+  let stmt_instrs =
+    rewrite_static_instrseq svar_map emit_expr env stmt_instrs
+  in
   let first_instruction_is_label =
     match Instruction_sequence.first stmt_instrs with
     | Some (ILabel _) -> true
@@ -447,6 +463,7 @@ let emit_body
       begin_label;
       header_content;
     ] in
+  let svar_instrs = SMap.ordered_keys svar_map in
   let body_instrs = gather [
     header;
     stmt_instrs;
@@ -464,6 +481,7 @@ let emit_body
     false (*is_memoize_wrapper_lsb*)
     params
     (Some return_type_info)
+    svar_instrs
     doc_comment
     (Some env),
     is_generator,

hphp/hack/src/hhbc/emit_body.mli

@@ -14,6 +14,7 @@ val make_body:
   bool ->
   Hhas_param.t list ->
   Hhas_type_info.t option ->
+  string list ->
   string option ->
   Emit_env.t option ->
   Hhas_body.t

hphp/hack/src/hhbc/emit_class.ml

@@ -59,6 +59,7 @@ let make_86method
   let method_is_memoize_wrapper_lsb = false in
   let method_no_injection = true in
   let method_inout_wrapper = false in
+  let method_static_inits = [] in
   let method_doc_comment = None in
   let method_is_interceptable = false in
   let method_is_memoize_impl = false in
@@ -70,6 +71,7 @@ let make_86method
     method_is_memoize_wrapper_lsb
     params
     method_return_type
+    method_static_inits
     method_doc_comment
     method_env in
   Hhas_method.make

hphp/hack/src/hhbc/emit_inout_function.ml

@@ -107,6 +107,7 @@ let make_wrapper_body env doc decl_vars return_type params instrs =
     false (* is_memoize_wrapper_lsb *)
     params
     (Some return_type)
+    [] (* static_inits: this is intentionally empty *)
     doc
     (Some env)
 

hphp/hack/src/hhbc/emit_memoize_function.ml

@@ -120,6 +120,7 @@ let make_wrapper_body env return_type params instrs =
     false (* is_memoize_wrapper_lsb *)
     params
     (Some return_type)
+    [] (* static_inits: this is intentionally empty *)
     None (* doc *)
     (Some env)
 

hphp/hack/src/hhbc/emit_memoize_method.ml

@@ -288,6 +288,7 @@ let make_wrapper env return_type params instrs with_lsb =
     with_lsb (* is_memoize_wrapper_lsb *)
     params
     (Some return_type)
+    [] (* static_inits *)
     None (* doc *)
     (Some env)
 

hphp/hack/src/hhbc/emit_native_opcode.ml

@@ -78,5 +78,6 @@ let emit_body scope namespace class_attrs name params ret =
     false
     params
     (Some return_type_info)
+    []
     None
     None

hphp/hack/src/hhbc/emit_program.ml

@@ -49,6 +49,7 @@ let emit_fatal_program ~ignore_message op pos message =
     false (*is_memoize_wrapper_lsb*)
     [] (* params *)
     None (* return_type_info *)
+    [] (* static_inits static_inits  *)
     None (* doc *)
     None (* env *)
   in

hphp/hack/src/hhbc/emit_statement.ml

@@ -286,6 +286,8 @@ let rec emit_stmt env (pos, st_) =
     emit_foreach env pos collection await_pos iterator (pos, A.Block block)
   | A.Def_inline def ->
     emit_def_inline def
+  | A.Static_var es ->
+    emit_static_var pos es
   | A.Global_var es ->
     emit_global_vars pos es
   | A.Awaitall el ->
@@ -359,6 +361,19 @@ and emit_global_vars p es =
       end in
   Emit_pos.emit_pos_then p @@ gather (List.rev instrs)
 
+and emit_static_var pos es =
+  let emit_static_var_single e =
+    match snd e with
+    | A.Lvar (_, name)
+    | A.Binop (A.Eq _, (_, A.Lvar (_, name)), _) ->
+      gather [
+        Emit_pos.emit_pos pos;
+        instr_static_loc_init name
+      ]
+    | _ -> failwith "Static var - impossible"
+  in
+  gather @@ List.map es ~f:emit_static_var_single
+
 and emit_awaitall env pos el =
   match el with
   | [] -> empty

hphp/hack/src/hhbc/hhas_body.ml

@@ -17,6 +17,7 @@ type t = {
   body_is_memoize_wrapper_lsb: bool;
   body_params            : Hhas_param.t list;
   body_return_type       : Hhas_type_info.t option;
+  body_static_inits      : string list;
   body_doc_comment       : string option;
   body_env               : Emit_env.t option;
 }
@@ -30,6 +31,7 @@ let make
   is_memoize_wrapper_lsb
   params
   return_type
+  static_inits
   doc_comment
   env =
   {
@@ -41,6 +43,7 @@ let make
     body_is_memoize_wrapper_lsb = is_memoize_wrapper_lsb;
     body_params = params;
     body_return_type = return_type;
+    body_static_inits = static_inits;
     body_doc_comment = doc_comment;
     body_env = env;
   }
@@ -54,5 +57,6 @@ let return_type body = body.body_return_type
 let is_memoize_wrapper body = body.body_is_memoize_wrapper
 let is_memoize_wrapper_lsb body = body.body_is_memoize_wrapper_lsb
 let with_instrs body instrs = { body with body_instrs = instrs }
+let static_inits body = body.body_static_inits
 let doc_comment body = body.body_doc_comment
 let env body = body.body_env