1 files changed, 222 insertions, 1 deletions

diff --git a/lib/stdlib/src/lib.erl b/lib/stdlib/src/lib.erl
index 56654097d9..aa6797bce6 100644
--- a/lib/stdlib/src/lib.erl
+++ b/lib/stdlib/src/lib.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1996-2016. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2017. All Rights Reserved.
 %% 
 %% Licensed under the Apache License, Version 2.0 (the "License");
 %% you may not use this file except in compliance with the License.
@@ -22,6 +22,9 @@
 -export([flush_receive/0, error_message/2, progname/0, nonl/1, send/2,
 	 sendw/2, eval_str/1]).
 
+-export([extended_parse_exprs/1, extended_parse_term/1,
+         subst_values_for_vars/2]).
+
 -export([format_exception/6, format_exception/7,
          format_stacktrace/4, format_stacktrace/5,
          format_call/4, format_call/5, format_fun/1]).
@@ -127,6 +130,224 @@ all_white([$\t|T]) -> all_white(T);
 all_white([])      -> true;
 all_white(_)       -> false.
 
+%% `Tokens' is assumed to have been scanned with the 'text' option.
+%% The annotations of the returned expressions are locations.
+%%
+%% Can handle pids, ports, references, and external funs ("items").
+%% Known items are represented by variables in the erl_parse tree, and
+%% the items themselves are stored in the returned bindings.
+
+-spec extended_parse_exprs(Tokens) ->
+                {'ok', ExprList, Bindings} | {'error', ErrorInfo} when
+      Tokens :: [erl_scan:token()],
+      ExprList :: [erl_parse:abstract_expr()],
+      Bindings :: erl_eval:binding_struct(),
+      ErrorInfo :: erl_parse:error_info().
+
+extended_parse_exprs(Tokens) ->
+    Ts = tokens_fixup(Tokens),
+    case erl_parse:parse_exprs(Ts) of
+        {ok, Exprs0} ->
+            {Exprs, Bs} = expr_fixup(Exprs0),
+            {ok, reset_expr_anno(Exprs), Bs};
+        _ErrorInfo ->
+            erl_parse:parse_exprs(reset_token_anno(Ts))
+    end.
+
+tokens_fixup([]) -> [];
+tokens_fixup([T|Ts]=Ts0) ->
+    try token_fixup(Ts0) of
+        {NewT, NewTs} ->
+            [NewT|tokens_fixup(NewTs)]
+    catch
+        _:_ ->
+            [T|tokens_fixup(Ts)]
+    end.
+
+token_fixup(Ts) ->
+    {AnnoL, NewTs, FixupTag} = unscannable(Ts),
+    String = lists:append([erl_anno:text(A) || A <- AnnoL]),
+    _ = (fixup_fun(FixupTag))(String),
+    NewAnno = erl_anno:set_text(fixup_text(FixupTag), hd(AnnoL)),
+    {{string, NewAnno, String}, NewTs}.
+
+unscannable([{'#', A1}, {var, A2, 'Fun'}, {'<', A3}, {atom, A4, _},
+             {'.', A5}, {float, A6, _}, {'>', A7}|Ts]) ->
+    {[A1, A2, A3, A4, A5, A6, A7], Ts, function};
+unscannable([{'#', A1}, {var, A2, 'Fun'}, {'<', A3}, {atom, A4, _},
+             {'.', A5}, {atom, A6, _}, {'.', A7}, {integer, A8, _},
+             {'>', A9}|Ts]) ->
+    {[A1, A2, A3, A4, A5, A6, A7, A8, A9], Ts, function};
+unscannable([{'<', A1}, {float, A2, _}, {'.', A3}, {integer, A4, _},
+             {'>', A5}|Ts]) ->
+    {[A1, A2, A3, A4, A5], Ts, pid};
+unscannable([{'#', A1}, {var, A2, 'Port'}, {'<', A3}, {float, A4, _},
+             {'>', A5}|Ts]) ->
+    {[A1, A2, A3, A4, A5], Ts, port};
+unscannable([{'#', A1}, {var, A2, 'Ref'}, {'<', A3}, {float, A4, _},
+             {'.', A5}, {float, A6, _}, {'>', A7}|Ts]) ->
+    {[A1, A2, A3, A4, A5, A6, A7], Ts, reference}.
+
+expr_fixup(Expr0) ->
+    {Expr, Bs, _} = expr_fixup(Expr0, erl_eval:new_bindings(), 1),
+    {Expr, Bs}.
+
+expr_fixup({string,A,S}=T, Bs0, I) ->
+    try string_fixup(A, S) of
+        Value ->
+            Var = new_var(I),
+            Bs = erl_eval:add_binding(Var, Value, Bs0),
+            {{var, A, Var}, Bs, I+1}
+    catch
+        _:_ ->
+            {T, Bs0, I}
+    end;
+expr_fixup(Tuple, Bs0, I0) when is_tuple(Tuple) ->
+    {L, Bs, I} = expr_fixup(tuple_to_list(Tuple), Bs0, I0),
+    {list_to_tuple(L), Bs, I};
+expr_fixup([E0|Es0], Bs0, I0) ->
+    {E, Bs1, I1} = expr_fixup(E0, Bs0, I0),
+    {Es, Bs, I} = expr_fixup(Es0, Bs1, I1),
+    {[E|Es], Bs, I};
+expr_fixup(T, Bs, I) ->
+    {T, Bs, I}.
+
+string_fixup(A, S) ->
+    Text = erl_anno:text(A),
+    FixupTag = fixup_tag(Text, S),
+    (fixup_fun(FixupTag))(S).
+
+new_var(I) ->
+    list_to_atom(lists:concat(['__ExtendedParseExprs_', I, '__'])).
+
+reset_token_anno(Tokens) ->
+    [setelement(2, T, (reset_anno())(element(2, T))) || T <- Tokens].
+
+reset_expr_anno(Exprs) ->
+    [erl_parse:map_anno(reset_anno(), E) || E <- Exprs].
+
+reset_anno() ->
+    fun(A) -> erl_anno:new(erl_anno:location(A)) end.
+
+fixup_fun(function)  -> fun function/1;
+fixup_fun(pid)       -> fun erlang:list_to_pid/1;
+fixup_fun(port)      -> fun erlang:list_to_port/1;
+fixup_fun(reference) -> fun erlang:list_to_ref/1.
+
+function(S) ->
+    %% External function.
+    {ok, [_, _, _,
+          {atom, _, Module}, _,
+          {atom, _, Function}, _,
+          {integer, _, Arity}|_], _} = erl_scan:string(S),
+    erlang:make_fun(Module, Function, Arity).
+
+fixup_text(function)  -> "function";
+fixup_text(pid)       -> "pid";
+fixup_text(port)      -> "port";
+fixup_text(reference) -> "reference".
+
+fixup_tag("function",  "#"++_) -> function;
+fixup_tag("pid",       "<"++_) -> pid;
+fixup_tag("port",      "#"++_) -> port;
+fixup_tag("reference", "#"++_) -> reference.
+
+%%% End of extended_parse_exprs.
+
+%% `Tokens' is assumed to have been scanned with the 'text' option.
+%%
+%% Can handle pids, ports, references, and external funs.
+
+-spec extended_parse_term(Tokens) ->
+                {'ok', Term} | {'error', ErrorInfo} when
+      Tokens :: [erl_scan:token()],
+      Term :: term(),
+      ErrorInfo :: erl_parse:error_info().
+
+extended_parse_term(Tokens) ->
+    case extended_parse_exprs(Tokens) of
+        {ok, [Expr], Bindings} ->
+            try normalise(Expr, Bindings) of
+                Term ->
+                    {ok, Term}
+            catch
+                _:_ ->
+                    Loc = erl_anno:location(element(2, Expr)),
+                    {error,{Loc,?MODULE,"bad term"}}
+            end;
+        {ok, [_,Expr|_], _Bindings} ->
+                Loc = erl_anno:location(element(2, Expr)),
+                {error,{Loc,?MODULE,"bad term"}};
+        {error, _} = Error ->
+            Error
+    end.
+
+%% From erl_parse.
+normalise({var, _, V}, Bs) ->
+    {value, Value} = erl_eval:binding(V, Bs),
+    Value;
+normalise({char,_,C}, _Bs) -> C;
+normalise({integer,_,I}, _Bs) -> I;
+normalise({float,_,F}, _Bs) -> F;
+normalise({atom,_,A}, _Bs) -> A;
+normalise({string,_,S}, _Bs) -> S;
+normalise({nil,_}, _Bs) -> [];
+normalise({bin,_,Fs}, Bs) ->
+    {value, B, _} =
+	eval_bits:expr_grp(Fs, [],
+			   fun(E, _) ->
+				   {value, normalise(E, Bs), []}
+			   end, [], true),
+    B;
+normalise({cons,_,Head,Tail}, Bs) ->
+    [normalise(Head, Bs)|normalise(Tail, Bs)];
+normalise({tuple,_,Args}, Bs) ->
+    list_to_tuple(normalise_list(Args, Bs));
+normalise({map,_,Pairs}, Bs) ->
+    maps:from_list(lists:map(fun
+		%% only allow '=>'
+		({map_field_assoc,_,K,V}) ->
+                                     {normalise(K, Bs),normalise(V, Bs)}
+	    end, Pairs));
+%% Special case for unary +/-.
+normalise({op,_,'+',{char,_,I}}, _Bs) -> I;
+normalise({op,_,'+',{integer,_,I}}, _Bs) -> I;
+normalise({op,_,'+',{float,_,F}}, _Bs) -> F;
+normalise({op,_,'-',{char,_,I}}, _Bs) -> -I;   %Weird, but compatible!
+normalise({op,_,'-',{integer,_,I}}, _Bs) -> -I;
+normalise({op,_,'-',{float,_,F}}, _Bs) -> -F;
+normalise({'fun',_,{function,{atom,_,M},{atom,_,F},{integer,_,A}}}, _Bs) ->
+    %% Since "#Fun<M.F.A>" is recognized, "fun M:F/A" should be too.
+    fun M:F/A.
+
+normalise_list([H|T], Bs) ->
+    [normalise(H, Bs)|normalise_list(T, Bs)];
+normalise_list([], _Bs) ->
+    [].
+
+%% To be used on ExprList and Bindings returned from extended_parse_exprs().
+%% Substitute {value, A, Item} for {var, A, ExtendedParseVar}.
+%% {value, A, Item} is a shell/erl_eval convention, and for example
+%% the linter cannot handle it.
+
+-spec subst_values_for_vars(ExprList, Bindings) -> [term()] when
+      ExprList :: [erl_parse:abstract_expr()],
+      Bindings :: erl_eval:binding_struct().
+
+subst_values_for_vars({var, A, V}=Var, Bs) ->
+    case erl_eval:binding(V, Bs) of
+        {value, Value} ->
+            {value, A, Value};
+        unbound ->
+            Var
+    end;
+subst_values_for_vars(L, Bs) when is_list(L) ->
+    [subst_values_for_vars(E, Bs) || E <- L];
+subst_values_for_vars(T, Bs) when is_tuple(T) ->
+    list_to_tuple(subst_values_for_vars(tuple_to_list(T), Bs));
+subst_values_for_vars(T, _Bs) ->
+    T.
+
 %%% Formatting of exceptions, mfa:s and funs.
 
 %% -> iolist() (no \n at end)