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erl_eval.erl
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%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1996-2011. All Rights Reserved.
%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
%%
%% %CopyrightEnd%
%%
-module(erl_eval).
%% An evaluator for Erlang abstract syntax.
-export([exprs/2,exprs/3,exprs/4,expr/2,expr/3,expr/4,expr/5,
expr_list/2,expr_list/3,expr_list/4]).
-export([new_bindings/0,bindings/1,binding/2,add_binding/3,del_binding/2]).
-export([is_constant_expr/1, partial_eval/1]).
%% Is used by standalone Erlang (escript).
%% Also used by shell.erl.
-export([resolve_unqualified_call/2]).
-export([match_clause/4]).
-export([check_command/2, fun_data/1]).
-import(lists, [reverse/1,foldl/3,member/2]).
-export_type([binding_struct/0]).
-type(expression() :: erl_parse:abstract_expr()).
-type(expressions() :: [erl_parse:abstract_expr()]).
-type(expression_list() :: [expression()]).
-type(clauses() :: [erl_parse:abstract_clause()]).
-type(name() :: term()).
-type(value() :: term()).
-type(bindings() :: [{name(), value()}]).
-type(binding_struct() :: orddict:orddict()).
-type(lfun_value_handler() :: fun((Name :: atom(),
Arguments :: [term()]) ->
Value :: value())).
-type(lfun_eval_handler() :: fun((Name :: atom(),
Arguments :: expression_list(),
Bindings :: binding_struct()) ->
{value,
Value :: value(),
NewBindings :: binding_struct()})).
-type(local_function_handler() :: {value, lfun_value_handler()}
| {eval, lfun_eval_handler()}
| none).
-type(func_spec() :: {Module :: module(), Function :: atom()} | function()).
-type(nlfun_handler() :: fun((FuncSpec :: func_spec(),
Arguments :: [term()]) ->
term())).
-type(non_local_function_handler() :: {value, nlfun_handler()}
| none).
%% exprs(ExpressionSeq, Bindings)
%% exprs(ExpressionSeq, Bindings, LocalFuncHandler)
%% exprs(ExpressionSeq, Bindings, LocalFuncHandler, ExternalFuncHandler)
%% Returns:
%% {value,Value,NewBindings}
%% or {'EXIT', Reason}
%% Only exprs/2 checks the command by calling erl_lint. The reason is
%% that if there is a function handler present, then it is possible
%% that there are valid constructs in Expression to be taken care of
%% by a function handler but considerad errors by erl_lint.
-spec(exprs(Expressions, Bindings) -> {value, Value, NewBindings} when
Expressions :: expressions(),
Bindings :: binding_struct(),
Value :: value(),
NewBindings :: binding_struct()).
exprs(Exprs, Bs) ->
case check_command(Exprs, Bs) of
ok ->
exprs(Exprs, Bs, none, none, none);
{error,{_Line,_Mod,Error}} ->
erlang:raise(error, Error, [{?MODULE,exprs,2}])
end.
-spec(exprs(Expressions, Bindings, LocalFunctionHandler) ->
{value, Value, NewBindings} when
Expressions :: expressions(),
Bindings :: binding_struct(),
LocalFunctionHandler :: local_function_handler(),
Value :: value(),
NewBindings :: binding_struct()).
exprs(Exprs, Bs, Lf) ->
exprs(Exprs, Bs, Lf, none, none).
-spec(exprs(Expressions, Bindings, LocalFunctionHandler,
NonLocalFunctionHandler) ->
{value, Value, NewBindings} when
Expressions :: expressions(),
Bindings :: binding_struct(),
LocalFunctionHandler :: local_function_handler(),
NonLocalFunctionHandler :: non_local_function_handler(),
Value :: value(),
NewBindings :: binding_struct()).
exprs(Exprs, Bs, Lf, Ef) ->
exprs(Exprs, Bs, Lf, Ef, none).
exprs([E], Bs0, Lf, Ef, RBs) ->
expr(E, Bs0, Lf, Ef, RBs);
exprs([E|Es], Bs0, Lf, Ef, RBs) ->
RBs1 = none,
{value,_V,Bs} = expr(E, Bs0, Lf, Ef, RBs1),
exprs(Es, Bs, Lf, Ef, RBs).
%% expr(Expression, Bindings)
%% expr(Expression, Bindings, LocalFuncHandler)
%% expr(Expression, Bindings, LocalFuncHandler, ExternalFuncHandler)
%% Returns:
%% {value,Value,NewBindings}
%% or {'EXIT', Reason}
%%
%% Only expr/2 checks the command by calling erl_lint. See exprs/2.
-spec(expr(Expression, Bindings) -> {value, Value, NewBindings} when
Expression :: expression(),
Bindings :: binding_struct(),
Value :: value(),
NewBindings :: binding_struct()).
expr(E, Bs) ->
case check_command([E], Bs) of
ok ->
expr(E, Bs, none, none, none);
{error,{_Line,_Mod,Error}} ->
erlang:raise(error, Error, [{?MODULE,expr,2}])
end.
-spec(expr(Expression, Bindings, LocalFunctionHandler) ->
{value, Value, NewBindings} when
Expression :: expression(),
Bindings :: binding_struct(),
LocalFunctionHandler :: local_function_handler(),
Value :: value(),
NewBindings :: binding_struct()).
expr(E, Bs, Lf) ->
expr(E, Bs, Lf, none, none).
-spec(expr(Expression, Bindings, LocalFunctionHandler,
NonLocalFunctionHandler) ->
{value, Value, NewBindings} when
Expression :: expression(),
Bindings :: binding_struct(),
LocalFunctionHandler :: local_function_handler(),
NonLocalFunctionHandler :: non_local_function_handler(),
Value :: value(),
NewBindings :: binding_struct()).
expr(E, Bs, Lf, Ef) ->
expr(E, Bs, Lf, Ef, none).
%% Check a command (a list of expressions) by calling erl_lint.
check_command(Es, Bs) ->
Opts = [bitlevel_binaries,binary_comprehension],
case erl_lint:exprs_opt(Es, bindings(Bs), Opts) of
{ok,_Ws} ->
ok;
{error,[{_File,[Error|_]}],_Ws} ->
{error,Error}
end.
%% Check whether a term F is a function created by this module.
%% Returns 'false' if not, otherwise {fun_data,Imports,Clauses}.
fun_data(F) when is_function(F) ->
case erlang:fun_info(F, module) of
{module,erl_eval} ->
{env, [FBs,_FEf,_FLf,FCs]} = erlang:fun_info(F, env),
{fun_data,FBs,FCs};
_ ->
false
end;
fun_data(_T) ->
false.
-spec(expr(Expression, Bindings, LocalFunctionHandler,
NonLocalFunctionHandler, ReturnFormat) ->
{value, Value, NewBindings} | Value when
Expression :: expression(),
Bindings :: binding_struct(),
LocalFunctionHandler :: local_function_handler(),
NonLocalFunctionHandler :: non_local_function_handler(),
ReturnFormat :: none | value,
Value :: value(),
NewBindings :: binding_struct()).
expr({var,_,V}, Bs, _Lf, _Ef, RBs) ->
case binding(V, Bs) of
{value,Val} ->
ret_expr(Val, Bs, RBs);
unbound -> % Should not happen.
erlang:raise(error, {unbound,V}, stacktrace())
end;
expr({char,_,C}, Bs, _Lf, _Ef, RBs) ->
ret_expr(C, Bs, RBs);
expr({integer,_,I}, Bs, _Lf, _Ef, RBs) ->
ret_expr(I, Bs, RBs);
expr({float,_,F}, Bs, _Lf, _Ef, RBs) ->
ret_expr(F, Bs, RBs);
expr({atom,_,A}, Bs, _Lf, _Ef, RBs) ->
ret_expr(A, Bs, RBs);
expr({string,_,S}, Bs, _Lf, _Ef, RBs) ->
ret_expr(S, Bs, RBs);
expr({nil, _}, Bs, _Lf, _Ef, RBs) ->
ret_expr([], Bs, RBs);
expr({cons,_,H0,T0}, Bs0, Lf, Ef, RBs) ->
{value,H,Bs1} = expr(H0, Bs0, Lf, Ef, none),
{value,T,Bs2} = expr(T0, Bs0, Lf, Ef, none),
ret_expr([H|T], merge_bindings(Bs1, Bs2), RBs);
expr({lc,_,E,Qs}, Bs, Lf, Ef, RBs) ->
eval_lc(E, Qs, Bs, Lf, Ef, RBs);
expr({bc,_,E,Qs}, Bs, Lf, Ef, RBs) ->
eval_bc(E, Qs, Bs, Lf, Ef, RBs);
expr({tuple,_,Es}, Bs0, Lf, Ef, RBs) ->
{Vs,Bs} = expr_list(Es, Bs0, Lf, Ef),
ret_expr(list_to_tuple(Vs), Bs, RBs);
expr({record_field,_,_,_}=Mod, Bs, _Lf, _Ef, RBs) ->
case expand_module_name(Mod, Bs) of
{atom,_,A} ->
ret_expr(A, Bs, RBs); %% This is the "x.y" syntax
_ ->
erlang:raise(error, {badexpr, '.'}, stacktrace())
end;
expr({record_field,_,_,Name,_}, _Bs, _Lf, _Ef, _RBs) ->
erlang:raise(error, {undef_record,Name}, stacktrace());
expr({record_index,_,Name,_}, _Bs, _Lf, _Ef, _RBs) ->
erlang:raise(error, {undef_record,Name}, stacktrace());
expr({record,_,Name,_}, _Bs, _Lf, _Ef, _RBs) ->
erlang:raise(error, {undef_record,Name}, stacktrace());
expr({record,_,_,Name,_}, _Bs, _Lf, _Ef, _RBs) ->
erlang:raise(error, {undef_record,Name}, stacktrace());
expr({block,_,Es}, Bs, Lf, Ef, RBs) ->
exprs(Es, Bs, Lf, Ef, RBs);
expr({'if',_,Cs}, Bs, Lf, Ef, RBs) ->
if_clauses(Cs, Bs, Lf, Ef, RBs);
expr({'case',_,E,Cs}, Bs0, Lf, Ef, RBs) ->
{value,Val,Bs} = expr(E, Bs0, Lf, Ef, none),
case_clauses(Val, Cs, Bs, Lf, Ef, RBs);
expr({'try',_,B,Cases,Catches,AB}, Bs, Lf, Ef, RBs) ->
try_clauses(B, Cases, Catches, AB, Bs, Lf, Ef, RBs);
expr({'receive',_,Cs}, Bs, Lf, Ef, RBs) ->
receive_clauses(Cs, Bs, Lf, Ef, [], RBs);
expr({'receive',_, Cs, E, TB}, Bs0, Lf, Ef, RBs) ->
{value,T,Bs} = expr(E, Bs0, Lf, Ef, none),
receive_clauses(T, Cs, {TB,Bs}, Bs0, Lf, Ef, [], RBs);
expr({'fun',_Line,{function,Mod0,Name0,Arity0}}, Bs0, Lf, Ef, RBs) ->
{[Mod,Name,Arity],Bs} = expr_list([Mod0,Name0,Arity0], Bs0, Lf, Ef),
F = erlang:make_fun(Mod, Name, Arity),
ret_expr(F, Bs, RBs);
expr({'fun',_Line,{function,Name,Arity}}, _Bs0, _Lf, _Ef, _RBs) -> % R8
%% Don't know what to do...
erlang:raise(error, undef, [{erl_eval,Name,Arity}|stacktrace()]);
expr({'fun',Line,{clauses,Cs}} = Ex, Bs, Lf, Ef, RBs) ->
%% Save only used variables in the function environment.
%% {value,L,V} are hidden while lint finds used variables.
{Ex1, _} = hide_calls(Ex, 0),
{ok,Used} = erl_lint:used_vars([Ex1], Bs),
En = orddict:filter(fun(K,_V) -> member(K,Used) end, Bs),
%% This is a really ugly hack!
F =
case length(element(3,hd(Cs))) of
0 -> fun () -> eval_fun(Cs, [], En, Lf, Ef) end;
1 -> fun (A) -> eval_fun(Cs, [A], En, Lf, Ef) end;
2 -> fun (A,B) -> eval_fun(Cs, [A,B], En, Lf, Ef) end;
3 -> fun (A,B,C) -> eval_fun(Cs, [A,B,C], En, Lf, Ef) end;
4 -> fun (A,B,C,D) -> eval_fun(Cs, [A,B,C,D], En, Lf, Ef) end;
5 -> fun (A,B,C,D,E) -> eval_fun(Cs, [A,B,C,D,E], En, Lf, Ef) end;
6 -> fun (A,B,C,D,E,F) -> eval_fun(Cs, [A,B,C,D,E,F], En, Lf, Ef) end;
7 -> fun (A,B,C,D,E,F,G) ->
eval_fun(Cs, [A,B,C,D,E,F,G], En, Lf, Ef) end;
8 -> fun (A,B,C,D,E,F,G,H) ->
eval_fun(Cs, [A,B,C,D,E,F,G,H], En, Lf, Ef) end;
9 -> fun (A,B,C,D,E,F,G,H,I) ->
eval_fun(Cs, [A,B,C,D,E,F,G,H,I], En, Lf, Ef) end;
10 -> fun (A,B,C,D,E,F,G,H,I,J) ->
eval_fun(Cs, [A,B,C,D,E,F,G,H,I,J], En, Lf, Ef) end;
11 -> fun (A,B,C,D,E,F,G,H,I,J,K) ->
eval_fun(Cs, [A,B,C,D,E,F,G,H,I,J,K], En, Lf, Ef) end;
12 -> fun (A,B,C,D,E,F,G,H,I,J,K,L) ->
eval_fun(Cs, [A,B,C,D,E,F,G,H,I,J,K,L], En, Lf, Ef) end;
13 -> fun (A,B,C,D,E,F,G,H,I,J,K,L,M) ->
eval_fun(Cs, [A,B,C,D,E,F,G,H,I,J,K,L,M], En, Lf, Ef) end;
14 -> fun (A,B,C,D,E,F,G,H,I,J,K,L,M,N) ->
eval_fun(Cs, [A,B,C,D,E,F,G,H,I,J,K,L,M,N], En, Lf, Ef) end;
15 -> fun (A,B,C,D,E,F,G,H,I,J,K,L,M,N,O) ->
eval_fun(Cs, [A,B,C,D,E,F,G,H,I,J,K,L,M,N,O], En, Lf, Ef) end;
16 -> fun (A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P) ->
eval_fun(Cs, [A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P], En, Lf, Ef) end;
17 -> fun (A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q) ->
eval_fun(Cs, [A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q], En, Lf, Ef) end;
18 -> fun (A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R) ->
eval_fun(Cs, [A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R], En, Lf, Ef) end;
19 -> fun (A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S) ->
eval_fun(Cs, [A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S],
En, Lf, Ef) end;
20 -> fun (A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T) ->
eval_fun(Cs, [A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T],
En, Lf, Ef) end;
_Other ->
erlang:raise(error, {'argument_limit',{'fun',Line,Cs}},
stacktrace())
end,
ret_expr(F, Bs, RBs);
expr({call,_,{remote,_,{atom,_,qlc},{atom,_,q}},[{lc,_,_E,_Qs}=LC | As0]},
Bs0, Lf, Ef, RBs) when length(As0) =< 1 ->
%% No expansion or evaluation of module name or function name.
MaxLine = find_maxline(LC),
{LC1, D} = hide_calls(LC, MaxLine),
case qlc:transform_from_evaluator(LC1, Bs0) of
{ok,{call,L,Remote,[QLC]}} ->
QLC1 = unhide_calls(QLC, MaxLine, D),
expr({call,L,Remote,[QLC1 | As0]}, Bs0, Lf, Ef, RBs);
{not_ok,Error} ->
ret_expr(Error, Bs0, RBs)
end;
expr({call,L1,{remote,L2,{record_field,_,{atom,_,''},{atom,_,qlc}=Mod},
{atom,_,q}=Func},
[{lc,_,_E,_Qs} | As0]=As},
Bs, Lf, Ef, RBs) when length(As0) =< 1 ->
expr({call,L1,{remote,L2,Mod,Func},As}, Bs, Lf, Ef, RBs);
expr({call,_,{remote,_,{atom,_,shell},{atom,_,Func}},As0}, Bs0, _Lf, _Ef, _RBs) ->
erl2:local2(shell, Func, As0, Bs0);
expr({call,_,{remote,_,{atom,_,mod},{atom,_,Func}},As0}, Bs0, _Lf, _Ef, _RBs) ->
erl2:local2(mod, Func, As0, Bs0);
expr({call,_,{remote,_,Mod,Func},As0}, Bs0, Lf, Ef, RBs) ->
case is_in_script(Mod,Func,length(As0)) of
true ->
{atom,_,AM} = Mod,
{atom,_,AF} = Func,
erl2:local2(AM, AF, As0, Bs0);
false ->
Mod1 = expand_module_name(Mod, Bs0),
{value,M,Bs1} = expr(Mod1, Bs0, Lf, Ef, none),
{value,F,Bs2} = expr(Func, Bs0, Lf, Ef, none),
{As,Bs3} = expr_list(As0, merge_bindings(Bs1, Bs2), Lf, Ef),
%% M could be a parameterized module (not an atom).
case is_atom(M) andalso erl_internal:bif(M, F, length(As)) of
true ->
bif(F, As, Bs3, Ef, RBs);
false ->
do_apply(M, F, As, Bs3, Ef, RBs)
end
end;
expr({call,_,{atom,_,Func},As0}, Bs0, Lf, Ef, RBs) ->
case erl_internal:bif(Func, length(As0)) of
true ->
{As,Bs} = expr_list(As0, Bs0, Lf, Ef),
bif(Func, As, Bs, Ef, RBs);
false ->
local_func(Func, As0, Bs0, Lf, RBs)
end;
expr({call,_,Func0,As0}, Bs0, Lf, Ef, RBs) -> % function or {Mod,Fun}
{value,Func,Bs1} = expr(Func0, Bs0, Lf, Ef, none),
{As,Bs2} = expr_list(As0, Bs1, Lf, Ef),
do_apply(Func, As, Bs2, Ef, RBs);
expr({'catch',_,Expr}, Bs0, Lf, Ef, RBs) ->
Ref = make_ref(),
case catch {Ref,expr(Expr, Bs0, Lf, Ef, none)} of
{Ref,{value,V,Bs}} -> % Nothing was thrown (guaranteed).
ret_expr(V, Bs, RBs);
Other ->
ret_expr(Other, Bs0, RBs)
end;
expr({match,_,Lhs,Rhs0}, Bs0, Lf, Ef, RBs) ->
{value,Rhs,Bs1} = expr(Rhs0, Bs0, Lf, Ef, none),
case match(Lhs, Rhs, Bs1) of
{match,Bs} ->
ret_expr(Rhs, Bs, RBs);
nomatch ->
erlang:raise(error, {badmatch,Rhs}, stacktrace())
end;
expr({op,_,Op,A0}, Bs0, Lf, Ef, RBs) ->
{value,A,Bs} = expr(A0, Bs0, Lf, Ef, none),
eval_op(Op, A, Bs, Ef, RBs);
expr({op,_,'andalso',L0,R0}, Bs0, Lf, Ef, RBs) ->
{value,L,Bs1} = expr(L0, Bs0, Lf, Ef, none),
V = case L of
true ->
{value,R,_} = expr(R0, Bs1, Lf, Ef, none),
R;
false -> false;
_ -> erlang:raise(error, {badarg,L}, stacktrace())
end,
ret_expr(V, Bs1, RBs);
expr({op,_,'orelse',L0,R0}, Bs0, Lf, Ef, RBs) ->
{value,L,Bs1} = expr(L0, Bs0, Lf, Ef, none),
V = case L of
true -> true;
false ->
{value,R,_} = expr(R0, Bs1, Lf, Ef, none),
R;
_ -> erlang:raise(error, {badarg,L}, stacktrace())
end,
ret_expr(V, Bs1, RBs);
expr({op,_,Op,L0,R0}, Bs0, Lf, Ef, RBs) ->
{value,L,Bs1} = expr(L0, Bs0, Lf, Ef, none),
{value,R,Bs2} = expr(R0, Bs0, Lf, Ef, none),
eval_op(Op, L, R, merge_bindings(Bs1, Bs2), Ef, RBs);
expr({bin,_,Fs}, Bs0, Lf, Ef, RBs) ->
EvalFun = fun(E, B) -> expr(E, B, Lf, Ef, none) end,
{value,V,Bs} = eval_bits:expr_grp(Fs, Bs0, EvalFun),
ret_expr(V, Bs, RBs);
expr({remote,_,_,_}, _Bs, _Lf, _Ef, _RBs) ->
erlang:raise(error, {badexpr,':'}, stacktrace());
expr({value,_,Val}, Bs, _Lf, _Ef, RBs) -> % Special case straight values.
ret_expr(Val, Bs, RBs);
%% Additions by JA
expr({form,F}, Bs0,_,_,_) ->
eval_form(F, Bs0),
{value, true, Bs0};
expr({define1,{function,_Ln,Name,Arity, Clauses}}, Bs0, _, _, _) ->
D = define_function(Name, Arity, Clauses, Bs0),
{value, D, Bs0};
expr({define2,
{atom,_,Name},
{'fun',_Ln,{clauses,Clauses}}
}, Bs0, _, _, _) ->
{clause,_Ln,Head,_,_} = hd(Clauses),
Arity = length(Head),
D = define_function(Name, Arity, Clauses, Bs0),
{value, D, Bs0};
expr({define3,Attr}, Bs0, _, _, _) ->
save({attribute, get(context), Attr}),
{value, true, Bs0};
expr({defMods, L}, Bs0, _, _, _) ->
Mods = [M || {atom,_,M} <- L],
put(defining_modules, Mods),
{value, true, Bs0};
expr({beginFunc,Args}, Bs0, _, _, _) ->
{{atom,Ln,_},_} = hd(Args),
Args1 = [{A,I} || {{atom,_,A},{integer,_,I}} <- Args],
put(current_function, {Ln,Args1}),
{value, true, Bs0};
expr({defExport,L}, Bs, _, _, _) ->
Es = [{F,N} || {{atom,_,F},{integer,_,N}} <- L],
save({export,get(context), Es}),
{value, Es, Bs};
expr(endFunc, Bs0, _, _, _) ->
put1(current_function, none),
{value, true, Bs0};
expr({addMod,{atom,Ln,Name}}, Bs0, _, _, _) ->
case get(current_function) of
none ->
put(current_module, Name),
{value, true, Bs0};
_ ->
erlang:error({error,line,Ln,cannotChangeModinFunc})
end;
expr({deleteFunc, {atom,Ln,Mod},{atom,_,Func},{integer,_,Arity}},
Bs0, _, _, _) ->
case erase({fundef,{Mod,Func,Arity}}) of
undefined ->
erlang:error({cannot,delete,Mod,Func,Arity,in,line,Ln});
_ ->
{value, true, Bs0}
end;
expr({call99,X,Args}, Bs0, _, _, _) ->
erl2:local99(X, Args, Bs0).
eval_form({function,_Ln,Name,Arity,Clauses}, Bs0) ->
define_function(Name, Arity, Clauses, Bs0);
eval_form({attribute,_,module,XX}=A, Bs0) ->
put(defining_modules,[XX]),
put(current_module,XX),
add_attribute(A),
{value, true, Bs0};
eval_form({attribute,_,_,_}=A, Bs0) ->
add_attribute(A),
{value, true, Bs0}.
find_maxline(LC) ->
put('$erl_eval_max_line', 0),
F = fun(L) ->
case is_integer(L) and (L > get('$erl_eval_max_line')) of
true -> put('$erl_eval_max_line', L);
false -> ok
end end,
_ = erl_lint:modify_line(LC, F),
erase('$erl_eval_max_line').
hide_calls(LC, MaxLine) ->
LineId0 = MaxLine + 1,
{NLC, _, D} = hide(LC, LineId0, dict:new()),
{NLC, D}.
%% v/1 and local calls are hidden.
hide({value,L,V}, Id, D) ->
{{atom,Id,ok}, Id+1, dict:store(Id, {value,L,V}, D)};
hide({call,L,{atom,_,N}=Atom,Args}, Id0, D0) ->
{NArgs, Id, D} = hide(Args, Id0, D0),
C = case erl_internal:bif(N, length(Args)) of
true ->
{call,L,Atom,NArgs};
false ->
{call,Id,{remote,L,{atom,L,m},{atom,L,f}},NArgs}
end,
{C, Id+1, dict:store(Id, {call,Atom}, D)};
hide(T0, Id0, D0) when is_tuple(T0) ->
{L, Id, D} = hide(tuple_to_list(T0), Id0, D0),
{list_to_tuple(L), Id, D};
hide([E0 | Es0], Id0, D0) ->
{E, Id1, D1} = hide(E0, Id0, D0),
{Es, Id, D} = hide(Es0, Id1, D1),
{[E | Es], Id, D};
hide(E, Id, D) ->
{E, Id, D}.
unhide_calls({atom,Id,ok}, MaxLine, D) when Id > MaxLine ->
dict:fetch(Id, D);
unhide_calls({call,Id,{remote,L,_M,_F},Args}, MaxLine, D) when Id > MaxLine ->
{call,Atom} = dict:fetch(Id, D),
{call,L,Atom,unhide_calls(Args, MaxLine, D)};
unhide_calls(T, MaxLine, D) when is_tuple(T) ->
list_to_tuple(unhide_calls(tuple_to_list(T), MaxLine, D));
unhide_calls([E | Es], MaxLine, D) ->
[unhide_calls(E, MaxLine, D) | unhide_calls(Es, MaxLine, D)];
unhide_calls(E, _MaxLine, _D) ->
E.
%% local_func(Function, Arguments, Bindings, LocalFuncHandler, RBs) ->
%% {value,Value,Bindings} | Value when
%% LocalFuncHandler = {value,F} | {value,F,Eas} |
%% {eval,F} | {eval,F,Eas} | none.
local_func(Func, As0, Bs0, {value,F}, value) ->
{As1,_Bs1} = expr_list(As0, Bs0, {value,F}),
%% Make tail recursive calls when possible.
F(Func, As1);
local_func(Func, As0, Bs0, {value,F}, RBs) ->
{As1,Bs1} = expr_list(As0, Bs0, {value,F}),
ret_expr(F(Func, As1), Bs1, RBs);
local_func(Func, As0, Bs0, {value,F,Eas}, RBs) ->
Fun = fun(Name, Args) -> apply(F, [Name,Args|Eas]) end,
local_func(Func, As0, Bs0, {value, Fun}, RBs);
local_func(Func, As, Bs, {eval,F}, RBs) ->
local_func2(F(Func, As, Bs), RBs);
local_func(Func, As, Bs, {eval,F,Eas}, RBs) ->
local_func2(apply(F, [Func,As,Bs|Eas]), RBs);
%% These two clauses are for backwards compatibility.
local_func(Func, As0, Bs0, {M,F}, RBs) ->
{As1,Bs1} = expr_list(As0, Bs0, {M,F}),
ret_expr(M:F(Func,As1), Bs1, RBs);
local_func(Func, As, _Bs, {M,F,Eas}, RBs) ->
local_func2(apply(M, F, [Func,As|Eas]), RBs);
%% Default unknown function handler to undefined function.
local_func(Func, As0, _Bs0, none, _RBs) ->
erlang:raise(error, undef, [{erl_eval,Func,length(As0)}|stacktrace()]).
local_func2({value,V,Bs}, RBs) ->
ret_expr(V, Bs, RBs);
local_func2({eval,F,As,Bs}, RBs) -> % This reply is not documented.
%% The shell found F. erl_eval tries to do a tail recursive call,
%% something the shell cannot do. Do not use Ef here.
do_apply(F, As, Bs, none, RBs).
%% bif(Name, Arguments, RBs)
%% Evaluate the Erlang auto-imported function Name. erlang:apply/2,3
%% are "hidden" from the external function handler.
bif(apply, [erlang,apply,As], Bs, Ef, RBs) ->
bif(apply, As, Bs, Ef, RBs);
bif(apply, [M,F,As], Bs, Ef, RBs) ->
do_apply(M, F, As, Bs, Ef, RBs);
bif(apply, [F,As], Bs, Ef, RBs) ->
do_apply(F, As, Bs, Ef, RBs);
bif(Name, As, Bs, Ef, RBs) ->
do_apply(erlang, Name, As, Bs, Ef, RBs).
%% do_apply(MF, Arguments, Bindings, ExternalFuncHandler, RBs) ->
%% {value,Value,Bindings} | Value when
%% ExternalFuncHandler = {value,F} | none.
%% MF is a tuple {Module,Function} or a fun.
do_apply({M,F}=Func, As, Bs0, Ef, RBs)
when tuple_size(M) >= 1, is_atom(element(1, M)), is_atom(F) ->
case Ef of
none when RBs =:= value ->
%% Make tail recursive calls when possible.
apply(M, F, As);
none ->
ret_expr(apply(M, F, As), Bs0, RBs);
{value,Fun} when RBs =:= value ->
Fun(Func, As);
{value,Fun} ->
ret_expr(Fun(Func, As), Bs0, RBs)
end;
do_apply(Func, As, Bs0, Ef, RBs) ->
Env = if
is_function(Func) ->
case {erlang:fun_info(Func, module),
erlang:fun_info(Func, env)} of
{{module,?MODULE},{env,Env1}} when Env1 =/= [] ->
{env,Env1};
_ ->
no_env
end;
true ->
no_env
end,
case {Env,Ef} of
{{env,[FBs, FEf, FLf, FCs]},_} ->
%% If we are evaluting within another function body
%% (RBs =/= none), we return RBs when this function body
%% has been evalutated, otherwise we return Bs0, the
%% bindings when evalution of this function body started.
NRBs = if
RBs =:= none -> Bs0;
true -> RBs
end,
case {erlang:fun_info(Func, arity), length(As)} of
{{arity, Arity}, Arity} ->
eval_fun(FCs, As, FBs, FLf, FEf, NRBs);
_ ->
erlang:raise(error, {badarity,{Func,As}},stacktrace())
end;
{no_env,none} when RBs =:= value ->
%% Make tail recursive calls when possible.
apply(Func, As);
{no_env,none} ->
ret_expr(apply(Func, As), Bs0, RBs);
{no_env,{value,F}} when RBs =:= value ->
F(Func,As);
{no_env,{value,F}} ->
ret_expr(F(Func, As), Bs0, RBs)
end.
do_apply(Mod, Func, As, Bs0, Ef, RBs) ->
case Ef of
none when RBs =:= value ->
%% Make tail recursive calls when possible.
apply(Mod, Func, As);
none ->
ret_expr(apply(Mod, Func, As), Bs0, RBs);
{value,F} when RBs =:= value ->
F({Mod,Func}, As);
{value,F} ->
ret_expr(F({Mod,Func}, As), Bs0, RBs)
end.
%% eval_lc(Expr, [Qualifier], Bindings, LocalFunctionHandler,
%% ExternalFuncHandler, RetBindings) ->
%% {value,Value,Bindings} | Value
eval_lc(E, Qs, Bs, Lf, Ef, RBs) ->
ret_expr(lists:reverse(eval_lc1(E, Qs, Bs, Lf, Ef, [])), Bs, RBs).
eval_lc1(E, [{generate,_,P,L0}|Qs], Bs0, Lf, Ef, Acc0) ->
{value,L1,_Bs1} = expr(L0, Bs0, Lf, Ef, none),
CompFun = fun(Bs, Acc) -> eval_lc1(E, Qs, Bs, Lf, Ef, Acc) end,
eval_generate(L1, P, Bs0, Lf, Ef, CompFun, Acc0);
eval_lc1(E, [{b_generate,_,P,L0}|Qs], Bs0, Lf, Ef, Acc0) ->
{value,Bin,_Bs1} = expr(L0, Bs0, Lf, Ef, none),
CompFun = fun(Bs, Acc) -> eval_lc1(E, Qs, Bs, Lf, Ef, Acc) end,
eval_b_generate(Bin, P, Bs0, Lf, Ef, CompFun, Acc0);
eval_lc1(E, [F|Qs], Bs0, Lf, Ef, Acc) ->
CompFun = fun(Bs) -> eval_lc1(E, Qs, Bs, Lf, Ef, Acc) end,
eval_filter(F, Bs0, Lf, Ef, CompFun, Acc);
eval_lc1(E, [], Bs, Lf, Ef, Acc) ->
{value,V,_} = expr(E, Bs, Lf, Ef, none),
[V|Acc].
%% eval_bc(Expr, [Qualifier], Bindings, LocalFunctionHandler,
%% ExternalFuncHandler, RetBindings) ->
%% {value,Value,Bindings} | Value
eval_bc(E, Qs, Bs, Lf, Ef, RBs) ->
ret_expr(eval_bc1(E, Qs, Bs, Lf, Ef, <<>>), Bs, RBs).
eval_bc1(E, [{b_generate,_,P,L0}|Qs], Bs0, Lf, Ef, Acc0) ->
{value,Bin,_Bs1} = expr(L0, Bs0, Lf, Ef, none),
CompFun = fun(Bs, Acc) -> eval_bc1(E, Qs, Bs, Lf, Ef, Acc) end,
eval_b_generate(Bin, P, Bs0, Lf, Ef, CompFun, Acc0);
eval_bc1(E, [{generate,_,P,L0}|Qs], Bs0, Lf, Ef, Acc0) ->
{value,List,_Bs1} = expr(L0, Bs0, Lf, Ef, none),
CompFun = fun(Bs, Acc) -> eval_bc1(E, Qs, Bs, Lf, Ef, Acc) end,
eval_generate(List, P, Bs0, Lf, Ef, CompFun, Acc0);
eval_bc1(E, [F|Qs], Bs0, Lf, Ef, Acc) ->
CompFun = fun(Bs) -> eval_bc1(E, Qs, Bs, Lf, Ef, Acc) end,
eval_filter(F, Bs0, Lf, Ef, CompFun, Acc);
eval_bc1(E, [], Bs, Lf, Ef, Acc) ->
{value,V,_} = expr(E, Bs, Lf, Ef, none),
<<Acc/bitstring,V/bitstring>>.
eval_generate([V|Rest], P, Bs0, Lf, Ef, CompFun, Acc) ->
case match(P, V, new_bindings(), Bs0) of
{match,Bsn} ->
Bs2 = add_bindings(Bsn, Bs0),
NewAcc = CompFun(Bs2, Acc),
eval_generate(Rest, P, Bs0, Lf, Ef, CompFun, NewAcc);
nomatch ->
eval_generate(Rest, P, Bs0, Lf, Ef, CompFun, Acc)
end;
eval_generate([], _P, _Bs0, _Lf, _Ef, _CompFun, Acc) ->
Acc;
eval_generate(Term, _P, _Bs0, _Lf, _Ef, _CompFun, _Acc) ->
erlang:raise(error, {bad_generator,Term}, stacktrace()).
eval_b_generate(<<_/bitstring>>=Bin, P, Bs0, Lf, Ef, CompFun, Acc) ->
Mfun = match_fun(Bs0),
Efun = fun(Exp, Bs) -> expr(Exp, Bs, Lf, Ef, none) end,
case eval_bits:bin_gen(P, Bin, new_bindings(), Bs0, Mfun, Efun) of
{match, Rest, Bs1} ->
Bs2 = add_bindings(Bs1, Bs0),
NewAcc = CompFun(Bs2, Acc),
eval_b_generate(Rest, P, Bs0, Lf, Ef, CompFun, NewAcc);
{nomatch, Rest} ->
eval_b_generate(Rest, P, Bs0, Lf, Ef, CompFun, Acc);
done ->
Acc
end;
eval_b_generate(Term, _P, _Bs0, _Lf, _Ef, _CompFun, _Acc) ->
erlang:raise(error, {bad_generator,Term}, stacktrace()).
eval_filter(F, Bs0, Lf, Ef, CompFun, Acc) ->
case erl_lint:is_guard_test(F) of
true ->
case guard_test(F, Bs0, Lf, Ef) of
{value,true,Bs1} -> CompFun(Bs1);
{value,false,_} -> Acc
end;
false ->
case expr(F, Bs0, Lf, Ef, none) of
{value,true,Bs1} -> CompFun(Bs1);
{value,false,_} -> Acc;
{value,V,_} ->
erlang:raise(error, {bad_filter,V}, stacktrace())
end
end.
%% RBs is the bindings to return when the evalution of a function
%% (fun) has finished. If RBs =:= none, then the evalution took place
%% outside a function. If RBs =:= value, only the value (not the bindings)
%% is to be returned (to a compiled function).
ret_expr(V, _Bs, value) ->
V;
ret_expr(V, Bs, none) ->
{value,V,Bs};
ret_expr(V, _Bs, RBs) when is_list(RBs) ->
{value,V,RBs}.
%% eval_fun(Clauses, Arguments, Bindings, LocalFunctionHandler,
%% ExternalFunctionHandler) -> Value
%% This function is called when the fun is called from compiled code
%% or from apply.
eval_fun(Cs, As, Bs0, Lf, Ef) ->
eval_fun(Cs, As, Bs0, Lf, Ef, value).
eval_fun([{clause,_,H,G,B}|Cs], As, Bs0, Lf, Ef, RBs) ->
case match_list(H, As, new_bindings(), Bs0) of
{match,Bsn} -> % The new bindings for the head
Bs1 = add_bindings(Bsn, Bs0), % which then shadow!
case guard(G, Bs1, Lf, Ef) of
true -> exprs(B, Bs1, Lf, Ef, RBs);
false -> eval_fun(Cs, As, Bs0, Lf, Ef, RBs)
end;
nomatch ->
eval_fun(Cs, As, Bs0, Lf, Ef, RBs)
end;
eval_fun([], As, _Bs, _Lf, _Ef, _RBs) ->
erlang:raise(error, function_clause,
[{?MODULE,'-inside-an-interpreted-fun-',As}|stacktrace()]).
%% expr_list(ExpressionList, Bindings)
%% expr_list(ExpressionList, Bindings, LocalFuncHandler)
%% expr_list(ExpressionList, Bindings, LocalFuncHandler, ExternalFuncHandler)
%% Evaluate a list of expressions "in parallel" at the same level.
-spec(expr_list(ExpressionList, Bindings) -> {ValueList, NewBindings} when
ExpressionList :: expression_list(),
Bindings :: binding_struct(),
ValueList :: [value()],
NewBindings :: binding_struct()).
expr_list(Es, Bs) ->
expr_list(Es, Bs, none, none).
-spec(expr_list(ExpressionList, Bindings, LocalFunctionHandler) ->
{ValueList, NewBindings} when
ExpressionList :: expression_list(),
Bindings :: binding_struct(),
LocalFunctionHandler :: local_function_handler(),
ValueList :: [value()],
NewBindings :: binding_struct()).
expr_list(Es, Bs, Lf) ->
expr_list(Es, Bs, Lf, none).
-spec(expr_list(ExpressionList, Bindings, LocalFunctionHandler,
NonLocalFunctionHandler) ->
{ValueList, NewBindings} when
ExpressionList :: expression_list(),
Bindings :: binding_struct(),
LocalFunctionHandler :: local_function_handler(),
NonLocalFunctionHandler :: non_local_function_handler(),
ValueList :: [value()],
NewBindings :: binding_struct()).
expr_list(Es, Bs, Lf, Ef) ->
expr_list(Es, [], Bs, Bs, Lf, Ef).
expr_list([E|Es], Vs, BsOrig, Bs0, Lf, Ef) ->
{value,V,Bs1} = expr(E, BsOrig, Lf, Ef, none),
expr_list(Es, [V|Vs], BsOrig, merge_bindings(Bs1, Bs0), Lf, Ef);
expr_list([], Vs, _, Bs, _Lf, _Ef) ->
{reverse(Vs),Bs}.
eval_op(Op, Arg1, Arg2, Bs, Ef, RBs) ->
do_apply(erlang, Op, [Arg1,Arg2], Bs, Ef, RBs).
eval_op(Op, Arg, Bs, Ef, RBs) ->
do_apply(erlang, Op, [Arg], Bs, Ef, RBs).
%% if_clauses(Clauses, Bindings, LocalFuncHandler, ExtFuncHandler, RBs)
if_clauses([{clause,_,[],G,B}|Cs], Bs, Lf, Ef, RBs) ->
case guard(G, Bs, Lf, Ef) of
true -> exprs(B, Bs, Lf, Ef, RBs);
false -> if_clauses(Cs, Bs, Lf, Ef, RBs)
end;
if_clauses([], _Bs, _Lf, _Ef, _RBs) ->
erlang:raise(error, if_clause, stacktrace()).
%% try_clauses(Body, CaseClauses, CatchClauses, AfterBody, Bindings,
%% LocalFuncHandler, ExtFuncHandler, RBs)
%% When/if variable bindings between the different parts of a
%% try-catch expression are introduced this will have to be rewritten.
try_clauses(B, Cases, Catches, AB, Bs, Lf, Ef, RBs) ->
try exprs(B, Bs, Lf, Ef, none) of
{value,V,Bs1} when Cases =:= [] ->
ret_expr(V, Bs1, RBs);
{value,V,Bs1} ->
case match_clause(Cases, [V], Bs1, Lf, Ef) of
{B2,Bs2} ->
exprs(B2, Bs2, Lf, Ef, RBs);
nomatch ->
erlang:raise(error, {try_clause,V}, stacktrace())
end
catch
Class:Reason when Catches =:= [] ->
%% Rethrow
erlang:raise(Class, Reason, stacktrace());
Class:Reason ->
%%% %% Set stacktrace
%%% try erlang:raise(Class, Reason, stacktrace())
%%% catch _:_ -> ok
%%% end,
V = {Class,Reason,erlang:get_stacktrace()},
case match_clause(Catches, [V],Bs, Lf, Ef) of
{B2,Bs2} ->
exprs(B2, Bs2, Lf, Ef, RBs);
nomatch ->
erlang:raise(Class, Reason, stacktrace())
end
after
if AB =:= [] ->
Bs; % any
true ->
exprs(AB, Bs, Lf, Ef, none)
end
end.
%% case_clauses(Value, Clauses, Bindings, LocalFuncHandler, ExtFuncHandler,
%% RBs)
case_clauses(Val, Cs, Bs, Lf, Ef, RBs) ->
case match_clause(Cs, [Val], Bs, Lf, Ef) of
{B, Bs1} ->
exprs(B, Bs1, Lf, Ef, RBs);
nomatch ->
erlang:raise(error, {case_clause,Val}, stacktrace())
end.
%%
%% receive_clauses(Clauses, Bindings, LocalFuncHnd,ExtFuncHnd, Messages, RBs)
%%
receive_clauses(Cs, Bs, Lf, Ef, Ms, RBs) ->
receive
Val ->
case match_clause(Cs, [Val], Bs, Lf, Ef) of
{B, Bs1} ->
merge_queue(Ms),
exprs(B, Bs1, Lf, Ef, RBs);
nomatch ->
receive_clauses(Cs, Bs, Lf, Ef, [Val|Ms], RBs)
end
end.
%%
%% receive_clauses(TimeOut, Clauses, TimeoutBody, Bindings,
%% ExternalFuncHandler, LocalFuncHandler, RBs)
%%
receive_clauses(T, Cs, TB, Bs, Lf, Ef, Ms, RBs) ->
{_,_} = statistics(runtime),
receive
Val ->
case match_clause(Cs, [Val], Bs, Lf, Ef) of
{B, Bs1} ->
merge_queue(Ms),
exprs(B, Bs1, Lf, Ef, RBs);
nomatch ->
{_,T1} = statistics(runtime),
if
T =:= infinity ->
receive_clauses(T, Cs, TB,Bs,Lf,Ef,[Val|Ms],RBs);
T-T1 =< 0 ->
receive_clauses(0, Cs, TB,Bs,Lf,Ef,[Val|Ms],RBs);
true ->
receive_clauses(T-T1, Cs,TB,Bs,Lf,Ef,[Val|Ms],RBs)
end
end
after T ->
merge_queue(Ms),
{B, Bs1} = TB,
exprs(B, Bs1, Lf, Ef, RBs)
end.
merge_queue([]) ->
true;
merge_queue(Ms) ->
send_all(recv_all(Ms), self()).
recv_all(Xs) ->
receive
X -> recv_all([X|Xs])
after 0 ->
reverse(Xs)
end.
send_all([X|Xs], Self) ->
Self ! X,
send_all(Xs, Self);
send_all([], _) -> true.
%% match_clause -> {Body, Bindings} or nomatch
-spec(match_clause(Clauses, ValueList, Bindings, LocalFunctionHandler) ->
{Body, NewBindings} | nomatch when
Clauses :: clauses(),
ValueList :: [value()],
Bindings :: binding_struct(),
LocalFunctionHandler :: local_function_handler(),
Body :: expression_list(),
NewBindings :: binding_struct()).
match_clause(Cs, Vs, Bs, Lf) ->
match_clause(Cs, Vs, Bs, Lf, none).
match_clause([{clause,_,H,G,B}|Cs], Vals, Bs, Lf, Ef) ->
case match_list(H, Vals, Bs) of
{match, Bs1} ->
case guard(G, Bs1, Lf, Ef) of
true -> {B, Bs1};
false -> match_clause(Cs, Vals, Bs, Lf, Ef)
end;
nomatch -> match_clause(Cs, Vals, Bs, Lf, Ef)
end;
match_clause([], _Vals, _Bs, _Lf, _Ef) ->
nomatch.
%% guard(GuardTests, Bindings, LocalFuncHandler, ExtFuncHandler) -> bool()
%% Evaluate a guard. We test if the guard is a true guard.
guard(L=[G|_], Bs0, Lf, Ef) when is_list(G) ->
guard1(L, Bs0, Lf, Ef);
guard(L, Bs0, Lf, Ef) ->
guard0(L, Bs0, Lf, Ef).
%% disjunction of guard conjunctions
guard1([G|Gs], Bs0, Lf, Ef) when is_list(G) ->
case guard0(G, Bs0, Lf, Ef) of
true ->
true;
false ->
guard1(Gs, Bs0, Lf, Ef)
end;
guard1([], _Bs, _Lf, _Ef) -> false.