diff options
Diffstat (limited to 'lib/dialyzer/test/options1_SUITE_data/src/compiler/sys_pre_expand.erl')
-rw-r--r-- | lib/dialyzer/test/options1_SUITE_data/src/compiler/sys_pre_expand.erl | 1026 |
1 files changed, 1026 insertions, 0 deletions
diff --git a/lib/dialyzer/test/options1_SUITE_data/src/compiler/sys_pre_expand.erl b/lib/dialyzer/test/options1_SUITE_data/src/compiler/sys_pre_expand.erl new file mode 100644 index 0000000000..08bc6cb147 --- /dev/null +++ b/lib/dialyzer/test/options1_SUITE_data/src/compiler/sys_pre_expand.erl @@ -0,0 +1,1026 @@ +%% ``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 via the world wide web 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. +%% +%% The Initial Developer of the Original Code is Ericsson Utvecklings AB. +%% Portions created by Ericsson are Copyright 1999, Ericsson Utvecklings +%% AB. All Rights Reserved.'' +%% +%% $Id: sys_pre_expand.erl,v 1.1 2008/12/17 09:53:42 mikpe Exp $ +%% +%% Purpose : Expand some source Erlang constructions. This is part of the +%% pre-processing phase. + +%% N.B. Although structs (tagged tuples) are not yet allowed in the +%% language there is code included in pattern/2 and expr/3 (commented out) +%% that handles them by transforming them to tuples. + +-module(sys_pre_expand). + +%% Main entry point. +-export([module/2]). + +-import(ordsets, [from_list/1,add_element/2, + union/1,union/2,intersection/1,intersection/2,subtract/2]). +-import(lists, [member/2,map/2,foldl/3,foldr/3,sort/1,reverse/1,duplicate/2]). + +-include("../my_include/erl_bits.hrl"). + +-record(expand, {module=[], %Module name + parameters=undefined, %Module parameters + package="", %Module package + exports=[], %Exports + imports=[], %Imports + mod_imports, %Module Imports + compile=[], %Compile flags + records=dict:new(), %Record definitions + attributes=[], %Attributes + defined=[], %Defined functions + vcount=0, %Variable counter + func=[], %Current function + arity=[], %Arity for current function + fcount=0, %Local fun count + fun_index=0, %Global index for funs + bitdefault, + bittypes + }). + +%% module(Forms, CompileOptions) +%% {ModuleName,Exports,TransformedForms} +%% Expand the forms in one module. N.B.: the lists of predefined +%% exports and imports are really ordsets! + +module(Fs, Opts) -> + %% Set pre-defined exported functions. + PreExp = [{module_info,0},{module_info,1}], + + %% Set pre-defined module imports. + PreModImp = [{erlang,erlang},{packages,packages}], + + %% Build initial expand record. + St0 = #expand{exports=PreExp, + mod_imports=dict:from_list(PreModImp), + compile=Opts, + defined=PreExp, + bitdefault = erl_bits:system_bitdefault(), + bittypes = erl_bits:system_bittypes() + }, + %% Expand the functions. + {Tfs,St1} = forms(Fs, foldl(fun define_function/2, St0, Fs)), + {Efs,St2} = expand_pmod(Tfs, St1), + %% Get the correct list of exported functions. + Exports = case member(export_all, St2#expand.compile) of + true -> St2#expand.defined; + false -> St2#expand.exports + end, + %% Generate all functions from stored info. + {Ats,St3} = module_attrs(St2#expand{exports = Exports}), + {Mfs,St4} = module_predef_funcs(St3), + {St4#expand.module, St4#expand.exports, Ats ++ Efs ++ Mfs, + St4#expand.compile}. + +expand_pmod(Fs0, St) -> + case St#expand.parameters of + undefined -> + {Fs0,St}; + Ps -> + {Fs1,Xs,Ds} = sys_expand_pmod:forms(Fs0, Ps, + St#expand.exports, + St#expand.defined), + A = length(Ps), + Vs = [{var,0,V} || V <- Ps], + N = {atom,0,St#expand.module}, + B = [{tuple,0,[N|Vs]}], + F = {function,0,new,A,[{clause,0,Vs,[],B}]}, + As = St#expand.attributes, + {[F|Fs1],St#expand{exports=add_element({new,A}, Xs), + defined=add_element({new,A}, Ds), + attributes = [{abstract, true} | As]}} + end. + +%% -type define_function(Form, State) -> State. +%% Add function to defined if form a function. + +define_function({function,_,N,A,_Cs}, St) -> + St#expand{defined=add_element({N,A}, St#expand.defined)}; +define_function(_, St) -> St. + +module_attrs(St) -> + {[{attribute,0,Name,Val} || {Name,Val} <- St#expand.attributes],St}. + +module_predef_funcs(St) -> + PreDef = [{module_info,0},{module_info,1}], + PreExp = PreDef, + {[{function,0,module_info,0, + [{clause,0,[],[], + [{call,0,{remote,0,{atom,0,erlang},{atom,0,get_module_info}}, + [{atom,0,St#expand.module}]}]}]}, + {function,0,module_info,1, + [{clause,0,[{var,0,'X'}],[], + [{call,0,{remote,0,{atom,0,erlang},{atom,0,get_module_info}}, + [{atom,0,St#expand.module},{var,0,'X'}]}]}]}], + St#expand{defined=union(from_list(PreDef), St#expand.defined), + exports=union(from_list(PreExp), St#expand.exports)}}. + +%% forms(Forms, State) -> +%% {TransformedForms,State'} +%% Process the forms. Attributes are lost and just affect the state. +%% Ignore uninteresting forms like eof and type. + +forms([{attribute,_,Name,Val}|Fs0], St0) -> + St1 = attribute(Name, Val, St0), + forms(Fs0, St1); +forms([{function,L,N,A,Cs}|Fs0], St0) -> + {Ff,St1} = function(L, N, A, Cs, St0), + {Fs,St2} = forms(Fs0, St1), + {[Ff|Fs],St2}; +forms([_|Fs], St) -> forms(Fs, St); +forms([], St) -> {[],St}. + +%% -type attribute(Attribute, Value, State) -> +%% State. +%% Process an attribute, this just affects the state. + +attribute(module, {Module, As}, St) -> + M = package_to_string(Module), + St#expand{module=list_to_atom(M), + package = packages:strip_last(M), + parameters=As}; +attribute(module, Module, St) -> + M = package_to_string(Module), + St#expand{module=list_to_atom(M), + package = packages:strip_last(M)}; +attribute(export, Es, St) -> + St#expand{exports=union(from_list(Es), St#expand.exports)}; +attribute(import, Is, St) -> + import(Is, St); +attribute(compile, C, St) when list(C) -> + St#expand{compile=St#expand.compile ++ C}; +attribute(compile, C, St) -> + St#expand{compile=St#expand.compile ++ [C]}; +attribute(record, {Name,Defs}, St) -> + St#expand{records=dict:store(Name, normalise_fields(Defs), + St#expand.records)}; +attribute(file, _File, St) -> St; %This is ignored +attribute(Name, Val, St) when list(Val) -> + St#expand{attributes=St#expand.attributes ++ [{Name,Val}]}; +attribute(Name, Val, St) -> + St#expand{attributes=St#expand.attributes ++ [{Name,[Val]}]}. + +function(L, N, A, Cs0, St0) -> + {Cs,St} = clauses(Cs0, St0#expand{func=N,arity=A,fcount=0}), + {{function,L,N,A,Cs},St}. + +%% -type clauses([Clause], State) -> +%% {[TransformedClause],State}. +%% Expand function clauses. + +clauses([{clause,Line,H0,G0,B0}|Cs0], St0) -> + {H,Hvs,_Hus,St1} = head(H0, St0), + {G,Gvs,_Gus,St2} = guard(G0, Hvs, St1), + {B,_Bvs,_Bus,St3} = exprs(B0, union(Hvs, Gvs), St2), + {Cs,St4} = clauses(Cs0, St3), + {[{clause,Line,H,G,B}|Cs],St4}; +clauses([], St) -> {[],St}. + +%% head(HeadPatterns, State) -> +%% {TransformedPatterns,Variables,UsedVariables,State'} + +head(As, St) -> pattern_list(As, St). + +%% pattern(Pattern, State) -> +%% {TransformedPattern,Variables,UsedVariables,State'} +%% BITS: added used variables for bit patterns with varaible length +%% + +pattern({var,_,'_'}=Var, St) -> %Ignore anonymous variable. + {Var,[],[],St}; +pattern({var,_,V}=Var, St) -> + {Var,[V],[],St}; +pattern({char,_,_}=Char, St) -> + {Char,[],[],St}; +pattern({integer,_,_}=Int, St) -> + {Int,[],[],St}; +pattern({float,_,_}=Float, St) -> + {Float,[],[],St}; +pattern({atom,_,_}=Atom, St) -> + {Atom,[],[],St}; +pattern({string,_,_}=String, St) -> + {String,[],[],St}; +pattern({nil,_}=Nil, St) -> + {Nil,[],[],St}; +pattern({cons,Line,H,T}, St0) -> + {TH,THvs,Hus,St1} = pattern(H, St0), + {TT,TTvs,Tus,St2} = pattern(T, St1), + {{cons,Line,TH,TT},union(THvs, TTvs),union(Hus,Tus),St2}; +pattern({tuple,Line,Ps}, St0) -> + {TPs,TPsvs,Tus,St1} = pattern_list(Ps, St0), + {{tuple,Line,TPs},TPsvs,Tus,St1}; +%%pattern({struct,Line,Tag,Ps}, St0) -> +%% {TPs,TPsvs,St1} = pattern_list(Ps, St0), +%% {{tuple,Line,[{atom,Line,Tag}|TPs]},TPsvs,St1}; +pattern({record_field,_,_,_}=M, St) -> + {expand_package(M, St), [], [], St}; % must be a package name +pattern({record_index,Line,Name,Field}, St) -> + {index_expr(Line, Field, Name, record_fields(Name, St)),[],[],St}; +pattern({record,Line,Name,Pfs}, St0) -> + Fs = record_fields(Name, St0), + {TMs,TMsvs,Us,St1} = pattern_list(pattern_fields(Fs, Pfs), St0), + {{tuple,Line,[{atom,Line,Name}|TMs]},TMsvs,Us,St1}; +pattern({bin,Line,Es0}, St0) -> + {Es1,Esvs,Esus,St1} = pattern_bin(Es0, St0), + {{bin,Line,Es1},Esvs,Esus,St1}; +pattern({op,_,'++',{nil,_},R}, St) -> + pattern(R, St); +pattern({op,_,'++',{cons,Li,H,T},R}, St) -> + pattern({cons,Li,H,{op,Li,'++',T,R}}, St); +pattern({op,_,'++',{string,Li,L},R}, St) -> + pattern(string_to_conses(Li, L, R), St); +pattern({match,Line,Pat1, Pat2}, St0) -> + {TH,Hvt,Hus,St1} = pattern(Pat2, St0), + {TT,Tvt,Tus,St2} = pattern(Pat1, St1), + {{match,Line,TT,TH}, union(Hvt,Tvt), union(Hus,Tus), St2}; +%% Compile-time pattern expressions, including unary operators. +pattern({op,Line,Op,A}, St) -> + { erl_eval:partial_eval({op,Line,Op,A}), [], [], St}; +pattern({op,Line,Op,L,R}, St) -> + { erl_eval:partial_eval({op,Line,Op,L,R}), [], [], St}. + +pattern_list([P0|Ps0], St0) -> + {P,Pvs,Pus,St1} = pattern(P0, St0), + {Ps,Psvs,Psus,St2} = pattern_list(Ps0, St1), + {[P|Ps],union(Pvs, Psvs),union(Pus, Psus),St2}; +pattern_list([], St) -> {[],[],[],St}. + +%% guard(Guard, VisibleVariables, State) -> +%% {TransformedGuard,NewVariables,UsedVariables,State'} +%% Transform a list of guard tests. We KNOW that this has been checked +%% and what the guards test are. Use expr for transforming the guard +%% expressions. + +guard([G0|Gs0], Vs, St0) -> + {G,Hvs,Hus,St1} = guard_tests(G0, Vs, St0), + {Gs,Tvs,Tus,St2} = guard(Gs0, Vs, St1), + {[G|Gs],union(Hvs, Tvs),union(Hus, Tus),St2}; +guard([], _, St) -> {[],[],[],St}. + +guard_tests([Gt0|Gts0], Vs, St0) -> + {Gt1,Gvs,Gus,St1} = guard_test(Gt0, Vs, St0), + {Gts1,Gsvs,Gsus,St2} = guard_tests(Gts0, union(Gvs, Vs), St1), + {[Gt1|Gts1],union(Gvs, Gsvs),union(Gus, Gsus),St2}; +guard_tests([], _, St) -> {[],[],[],St}. + +guard_test({call,Line,{atom,_,record},[A,{atom,_,Name}]}, Vs, St) -> + record_test_in_guard(Line, A, Name, Vs, St); +guard_test({call,Line,{atom,Lt,Tname},As}, Vs, St) -> + %% XXX This is ugly. We can remove this workaround if/when + %% we'll allow 'andalso' in guards. For now, we must have + %% different code in guards and in bodies. + Test = {remote,Lt, + {atom,Lt,erlang}, + {atom,Lt,normalise_test(Tname, length(As))}}, + put(sys_pre_expand_in_guard, yes), + R = expr({call,Line,Test,As}, Vs, St), + erase(sys_pre_expand_in_guard), + R; +guard_test(Test, Vs, St) -> + %% XXX See the previous clause. + put(sys_pre_expand_in_guard, yes), + R = expr(Test, Vs, St), + erase(sys_pre_expand_in_guard), + R. + +%% record_test(Line, Term, Name, Vs, St) -> TransformedExpr +%% Generate code for is_record/1. + +record_test(Line, Term, Name, Vs, St) -> + case get(sys_pre_expand_in_guard) of + undefined -> + record_test_in_body(Line, Term, Name, Vs, St); + yes -> + record_test_in_guard(Line, Term, Name, Vs, St) + end. + +record_test_in_guard(Line, Term, Name, Vs, St) -> + %% Notes: (1) To keep is_record/3 properly atomic (e.g. when inverted + %% using 'not'), we cannot convert it to an instruction + %% sequence here. It must remain a single call. + %% (2) Later passes assume that the last argument (the size) + %% is a literal. + %% (3) We don't want calls to erlang:is_record/3 (in the source code) + %% confused we the internal instruction. (Reason: (2) above + + %% code bloat.) + %% (4) Xref may be run on the abstract code, so the name in the + %% abstract code must be erlang:is_record/3. + %% (5) To achive both (3) and (4) at the same time, set the name + %% here to erlang:is_record/3, but mark it as compiler-generated. + %% The v3_core pass will change the name to erlang:internal_is_record/3. + Fs = record_fields(Name, St), + expr({call,-Line,{remote,-Line,{atom,-Line,erlang},{atom,-Line,is_record}}, + [Term,{atom,Line,Name},{integer,Line,length(Fs)+1}]}, + Vs, St). + +record_test_in_body(Line, Expr, Name, Vs, St0) -> + %% As Expr may have side effects, we must evaluate it + %% first and bind the value to a new variable. + %% We must use also handle the case that Expr does not + %% evaluate to a tuple properly. + Fs = record_fields(Name, St0), + {Var,St} = new_var(Line, St0), + + expr({block,Line, + [{match,Line,Var,Expr}, + {op,Line, + 'andalso', + {call,Line,{atom,Line,is_tuple},[Var]}, + {op,Line,'andalso', + {op,Line,'=:=', + {call,Line,{atom,Line,size},[Var]}, + {integer,Line,length(Fs)+1}}, + {op,Line,'=:=', + {call,Line,{atom,Line,element},[{integer,Line,1},Var]}, + {atom,Line,Name}}}}]}, Vs, St). + +normalise_test(atom, 1) -> is_atom; +normalise_test(binary, 1) -> is_binary; +normalise_test(constant, 1) -> is_constant; +normalise_test(float, 1) -> is_float; +normalise_test(function, 1) -> is_function; +normalise_test(integer, 1) -> is_integer; +normalise_test(list, 1) -> is_list; +normalise_test(number, 1) -> is_number; +normalise_test(pid, 1) -> is_pid; +normalise_test(port, 1) -> is_port; +normalise_test(reference, 1) -> is_reference; +normalise_test(tuple, 1) -> is_tuple; +normalise_test(Name, _) -> Name. + +%% exprs(Expressions, VisibleVariables, State) -> +%% {TransformedExprs,NewVariables,UsedVariables,State'} + +exprs([E0|Es0], Vs, St0) -> + {E,Evs,Eus,St1} = expr(E0, Vs, St0), + {Es,Esvs,Esus,St2} = exprs(Es0, union(Evs, Vs), St1), + {[E|Es],union(Evs, Esvs),union(Eus, Esus),St2}; +exprs([], _, St) -> {[],[],[],St}. + +%% expr(Expression, VisibleVariables, State) -> +%% {TransformedExpression,NewVariables,UsedVariables,State'} + +expr({var,_,V}=Var, _Vs, St) -> + {Var,[],[V],St}; +expr({char,_,_}=Char, _Vs, St) -> + {Char,[],[],St}; +expr({integer,_,_}=Int, _Vs, St) -> + {Int,[],[],St}; +expr({float,_,_}=Float, _Vs, St) -> + {Float,[],[],St}; +expr({atom,_,_}=Atom, _Vs, St) -> + {Atom,[],[],St}; +expr({string,_,_}=String, _Vs, St) -> + {String,[],[],St}; +expr({nil,_}=Nil, _Vs, St) -> + {Nil,[],[],St}; +expr({cons,Line,H0,T0}, Vs, St0) -> + {H,Hvs,Hus,St1} = expr(H0, Vs, St0), + {T,Tvs,Tus,St2} = expr(T0, Vs, St1), + {{cons,Line,H,T},union(Hvs, Tvs),union(Hus, Tus),St2}; +expr({lc,Line,E0,Qs0}, Vs, St0) -> + {E1,Qs1,_,Lvs,Lus,St1} = lc_tq(Line, E0, Qs0, {nil,Line}, Vs, St0), + {{lc,Line,E1,Qs1},Lvs,Lus,St1}; +expr({tuple,Line,Es0}, Vs, St0) -> + {Es1,Esvs,Esus,St1} = expr_list(Es0, Vs, St0), + {{tuple,Line,Es1},Esvs,Esus,St1}; +%%expr({struct,Line,Tag,Es0}, Vs, St0) -> +%% {Es1,Esvs,Esus,St1} = expr_list(Es0, Vs, St0), +%% {{tuple,Line,[{atom,Line,Tag}|Es1]},Esvs,Esus,St1}; +expr({record_field,_,_,_}=M, _Vs, St) -> + {expand_package(M, St), [], [], St}; % must be a package name +expr({record_index,Line,Name,F}, Vs, St) -> + I = index_expr(Line, F, Name, record_fields(Name, St)), + expr(I, Vs, St); +expr({record,Line,Name,Is}, Vs, St) -> + expr({tuple,Line,[{atom,Line,Name}| + record_inits(record_fields(Name, St), Is)]}, + Vs, St); +expr({record_field,Line,R,Name,F}, Vs, St) -> + I = index_expr(Line, F, Name, record_fields(Name, St)), + expr({call,Line,{atom,Line,element},[I,R]}, Vs, St); +expr({record,_,R,Name,Us}, Vs, St0) -> + {Ue,St1} = record_update(R, Name, record_fields(Name, St0), Us, St0), + expr(Ue, Vs, St1); +expr({bin,Line,Es0}, Vs, St0) -> + {Es1,Esvs,Esus,St1} = expr_bin(Es0, Vs, St0), + {{bin,Line,Es1},Esvs,Esus,St1}; +expr({block,Line,Es0}, Vs, St0) -> + {Es,Esvs,Esus,St1} = exprs(Es0, Vs, St0), + {{block,Line,Es},Esvs,Esus,St1}; +expr({'if',Line,Cs0}, Vs, St0) -> + {Cs,Csvss,Csuss,St1} = icr_clauses(Cs0, Vs, St0), + All = new_in_all(Vs, Csvss), + {{'if',Line,Cs},All,union(Csuss),St1}; +expr({'case',Line,E0,Cs0}, Vs, St0) -> + {E,Evs,Eus,St1} = expr(E0, Vs, St0), + {Cs,Csvss,Csuss,St2} = icr_clauses(Cs0, union(Evs, Vs), St1), + All = new_in_all(Vs, Csvss), + {{'case',Line,E,Cs},union(Evs, All),union([Eus|Csuss]),St2}; +expr({'cond',Line,Cs}, Vs, St0) -> + {V,St1} = new_var(Line,St0), + expr(cond_clauses(Cs,V), Vs, St1); +expr({'receive',Line,Cs0}, Vs, St0) -> + {Cs,Csvss,Csuss,St1} = icr_clauses(Cs0, Vs, St0), + All = new_in_all(Vs, Csvss), + {{'receive',Line,Cs},All,union(Csuss),St1}; +expr({'receive',Line,Cs0,To0,ToEs0}, Vs, St0) -> + {To,Tovs,Tous,St1} = expr(To0, Vs, St0), + {ToEs,ToEsvs,_ToEsus,St2} = exprs(ToEs0, Vs, St1), + {Cs,Csvss,Csuss,St3} = icr_clauses(Cs0, Vs, St2), + All = new_in_all(Vs, [ToEsvs|Csvss]), + {{'receive',Line,Cs,To,ToEs},union(Tovs, All),union([Tous|Csuss]),St3}; +expr({'fun',Line,Body}, Vs, St) -> + fun_tq(Line, Body, Vs, St); +%%% expr({call,_,{atom,La,this_module},[]}, _Vs, St) -> +%%% {{atom,La,St#expand.module}, [], [], St}; +%%% expr({call,_,{atom,La,this_package},[]}, _Vs, St) -> +%%% {{atom,La,list_to_atom(St#expand.package)}, [], [], St}; +%%% expr({call,_,{atom,La,this_package},[{atom,_,Name}]}, _Vs, St) -> +%%% M = packages:concat(St#expand.package,Name), +%%% {{atom,La,list_to_atom(M)}, [], [], St}; +%%% expr({call,Line,{atom,La,this_package},[A]}, Vs, St) -> +%%% M = {call,Line,{remote,La,{atom,La,packages},{atom,La,concat}}, +%%% [{string,La,St#expand.package}, A]}, +%%% expr({call,Line,{atom,Line,list_to_atom},[M]}, Vs, St); +expr({call,Line,{atom,_,is_record},[A,{atom,_,Name}]}, Vs, St) -> + record_test(Line, A, Name, Vs, St); +expr({call,Line,{remote,_,{atom,_,erlang},{atom,_,is_record}}, + [A,{atom,_,Name}]}, Vs, St) -> + record_test(Line, A, Name, Vs, St); +expr({call,Line,{atom,La,N},As0}, Vs, St0) -> + {As,Asvs,Asus,St1} = expr_list(As0, Vs, St0), + Ar = length(As), + case erl_internal:bif(N, Ar) of + true -> + {{call,Line,{remote,La,{atom,La,erlang},{atom,La,N}},As}, + Asvs,Asus,St1}; + false -> + case imported(N, Ar, St1) of + {yes,Mod} -> + {{call,Line,{remote,La,{atom,La,Mod},{atom,La,N}},As}, + Asvs,Asus,St1}; + no -> + case {N,Ar} of + {record_info,2} -> + record_info_call(Line, As, St1); + _ -> + {{call,Line,{atom,La,N},As},Asvs,Asus,St1} + end + end + end; +expr({call,Line,{record_field,_,_,_}=M,As0}, Vs, St0) -> + expr({call,Line,expand_package(M, St0),As0}, Vs, St0); +expr({call,Line,{remote,Lr,M,F},As0}, Vs, St0) -> + M1 = expand_package(M, St0), + {[M2,F1|As1],Asvs,Asus,St1} = expr_list([M1,F|As0], Vs, St0), + {{call,Line,{remote,Lr,M2,F1},As1},Asvs,Asus,St1}; +expr({call,Line,{tuple,_,[{atom,_,_}=M,{atom,_,_}=F]},As}, Vs, St) -> + %% Rewrite {Mod,Function}(Args...) to Mod:Function(Args...). + expr({call,Line,{remote,Line,M,F},As}, Vs, St); +expr({call,Line,F,As0}, Vs, St0) -> + {[Fun1|As1],Asvs,Asus,St1} = expr_list([F|As0], Vs, St0), + {{call,Line,Fun1,As1},Asvs,Asus,St1}; +expr({'try',Line,Es0,Scs0,Ccs0,As0}, Vs, St0) -> + {Es1,Esvs,Esus,St1} = exprs(Es0, Vs, St0), + Cvs = union(Esvs, Vs), + {Scs1,Scsvss,Scsuss,St2} = icr_clauses(Scs0, Cvs, St1), + {Ccs1,Ccsvss,Ccsuss,St3} = icr_clauses(Ccs0, Cvs, St2), + Csvss = Scsvss ++ Ccsvss, + Csuss = Scsuss ++ Ccsuss, + All = new_in_all(Vs, Csvss), + {As1,Asvs,Asus,St4} = exprs(As0, Cvs, St3), + {{'try',Line,Es1,Scs1,Ccs1,As1}, union([Asvs,Esvs,All]), + union([Esus,Asus|Csuss]), St4}; +expr({'catch',Line,E0}, Vs, St0) -> + %% Catch exports no new variables. + {E,_Evs,Eus,St1} = expr(E0, Vs, St0), + {{'catch',Line,E},[],Eus,St1}; +expr({match,Line,P0,E0}, Vs, St0) -> + {E,Evs,Eus,St1} = expr(E0, Vs, St0), + {P,Pvs,Pus,St2} = pattern(P0, St1), + {{match,Line,P,E}, + union(subtract(Pvs, Vs), Evs), + union(intersection(Pvs, Vs), union(Eus,Pus)),St2}; +expr({op,L,'andalso',E1,E2}, Vs, St0) -> + {V,St1} = new_var(L,St0), + E = make_bool_switch(L,E1,V, + make_bool_switch(L,E2,V,{atom,L,true}, + {atom,L,false}), + {atom,L,false}), + expr(E, Vs, St1); +expr({op,L,'orelse',E1,E2}, Vs, St0) -> + {V,St1} = new_var(L,St0), + E = make_bool_switch(L,E1,V,{atom,L,true}, + make_bool_switch(L,E2,V,{atom,L,true}, + {atom,L,false})), + expr(E, Vs, St1); +expr({op,Line,'++',{lc,Ll,E0,Qs0},M0}, Vs, St0) -> + {E1,Qs1,M1,Lvs,Lus,St1} = lc_tq(Ll, E0, Qs0, M0, Vs, St0), + {{op,Line,'++',{lc,Ll,E1,Qs1},M1},Lvs,Lus,St1}; +expr({op,_,'++',{string,L1,S1},{string,_,S2}}, _Vs, St) -> + {{string,L1,S1 ++ S2},[],[],St}; +expr({op,Ll,'++',{string,L1,S1}=Str,R0}, Vs, St0) -> + {R1,Rvs,Rus,St1} = expr(R0, Vs, St0), + E = case R1 of + {string,_,S2} -> {string,L1,S1 ++ S2}; + _Other when length(S1) < 8 -> string_to_conses(L1, S1, R1); + _Other -> {op,Ll,'++',Str,R1} + end, + {E,Rvs,Rus,St1}; +expr({op,Ll,'++',{cons,Lc,H,T},L2}, Vs, St) -> + expr({cons,Ll,H,{op,Lc,'++',T,L2}}, Vs, St); +expr({op,_,'++',{nil,_},L2}, Vs, St) -> + expr(L2, Vs, St); +expr({op,Line,Op,A0}, Vs, St0) -> + {A,Avs,Aus,St1} = expr(A0, Vs, St0), + {{op,Line,Op,A},Avs,Aus,St1}; +expr({op,Line,Op,L0,R0}, Vs, St0) -> + {L,Lvs,Lus,St1} = expr(L0, Vs, St0), + {R,Rvs,Rus,St2} = expr(R0, Vs, St1), + {{op,Line,Op,L,R},union(Lvs, Rvs),union(Lus, Rus),St2}. + +expr_list([E0|Es0], Vs, St0) -> + {E,Evs,Eus,St1} = expr(E0, Vs, St0), + {Es,Esvs,Esus,St2} = expr_list(Es0, Vs, St1), + {[E|Es],union(Evs, Esvs),union(Eus, Esus),St2}; +expr_list([], _, St) -> + {[],[],[],St}. + +%% icr_clauses([Clause], [VisibleVariable], State) -> +%% {[TransformedClause],[[NewVariable]],[[UsedVariable]],State'} +%% Be very careful here to return the variables that are really used +%% and really new. + +icr_clauses([], _, St) -> + {[],[[]],[],St}; +icr_clauses(Clauses, Vs, St) -> + icr_clauses2(Clauses, Vs, St). + +icr_clauses2([{clause,Line,H0,G0,B0}|Cs0], Vs, St0) -> + {H,Hvs,Hus,St1} = head(H0, St0), %Hvs is really used! + {G,Gvs,Gus,St2} = guard(G0, union(Hvs, Vs), St1), + {B,Bvs,Bus,St3} = exprs(B0, union([Vs,Hvs,Gvs]), St2), + New = subtract(union([Hvs,Gvs,Bvs]), Vs), %Really new + Used = intersection(union([Hvs,Hus,Gus,Bus]), Vs), %Really used + {Cs,Csvs,Csus,St4} = icr_clauses2(Cs0, Vs, St3), + {[{clause,Line,H,G,B}|Cs],[New|Csvs],[Used|Csus],St4}; +icr_clauses2([], _, St) -> + {[],[],[],St}. + +%% lc_tq(Line, Expr, Qualifiers, More, [VisibleVar], State) -> +%% {TransExpr,[TransQual],TransMore,[NewVar],[UsedVar],State'} + +lc_tq(Line, E0, [{generate,Lg,P0,G0}|Qs0], M0, Vs, St0) -> + {G1,Gvs,Gus,St1} = expr(G0, Vs, St0), + {P1,Pvs,Pus,St2} = pattern(P0, St1), + {E1,Qs1,M1,Lvs,Lus,St3} = lc_tq(Line, E0, Qs0, M0, union(Pvs, Vs), St2), + {E1,[{generate,Lg,P1,G1}|Qs1],M1, + union(Gvs, Lvs),union([Gus,Pus,Lus]),St3}; +lc_tq(Line, E0, [F0|Qs0], M0, Vs, St0) -> + %% Allow record/2 and expand out as guard test. + case erl_lint:is_guard_test(F0) of + true -> + {F1,Fvs,_Fus,St1} = guard_tests([F0], Vs, St0), + {E1,Qs1,M1,Lvs,Lus,St2} = lc_tq(Line, E0, Qs0, M0, union(Fvs, Vs), St1), + {E1,F1++Qs1,M1,Lvs,Lus,St2}; + false -> + {F1,Fvs,_Fus,St1} = expr(F0, Vs, St0), + {E1,Qs1,M1,Lvs,Lus,St2} = lc_tq(Line, E0, Qs0, M0, union(Fvs, Vs), St1), + {E1,[F1|Qs1],M1,Lvs,Lus,St2} + end; +lc_tq(_Line, E0, [], M0, Vs, St0) -> + {E1,Evs,Eus,St1} = expr(E0, Vs, St0), + {M1,Mvs,Mus,St2} = expr(M0, Vs, St1), + {E1,[],M1,union(Evs, Mvs),union(Eus, Mus),St2}. + +%% fun_tq(Line, Body, VisibleVariables, State) -> +%% {Fun,NewVariables,UsedVariables,State'} +%% Transform an "explicit" fun {'fun', Line, {clauses, Cs}} into an +%% extended form {'fun', Line, {clauses, Cs}, Info}, unless it is the +%% name of a BIF (erl_lint has checked that it is not an import). +%% Process the body sequence directly to get the new and used variables. +%% "Implicit" funs {'fun', Line, {function, F, A}} are not changed. + +fun_tq(Lf, {function,F,A}, Vs, St0) -> + {As,St1} = new_vars(A, Lf, St0), + Cs = [{clause,Lf,As,[],[{call,Lf,{atom,Lf,F},As}]}], + case erl_internal:bif(F, A) of + true -> + fun_tq(Lf, {clauses,Cs}, Vs, St1); + false -> + Index = St0#expand.fun_index, + Uniq = erlang:hash(Cs, (1 bsl 27)-1), + {Fname,St2} = new_fun_name(St1), + {{'fun',Lf,{function,F,A},{Index,Uniq,Fname}},[],[], + St2#expand{fun_index=Index+1}} + end; +fun_tq(Lf, {clauses,Cs0}, Vs, St0) -> + Uniq = erlang:hash(Cs0, (1 bsl 27)-1), + {Cs1,_Hvss,Frees,St1} = fun_clauses(Cs0, Vs, St0), + Ufrees = union(Frees), + Index = St1#expand.fun_index, + {Fname,St2} = new_fun_name(St1), + {{'fun',Lf,{clauses,Cs1},{Index,Uniq,Fname}},[],Ufrees, + St2#expand{fun_index=Index+1}}. + +fun_clauses([{clause,L,H0,G0,B0}|Cs0], Vs, St0) -> + {H,Hvs,Hus,St1} = head(H0, St0), + {G,Gvs,Gus,St2} = guard(G0, union(Hvs, Vs), St1), + {B,Bvs,Bus,St3} = exprs(B0, union([Vs,Hvs,Gvs]), St2), + %% Free variables cannot be new anywhere in the clause. + Free = subtract(union([Gus,Hus,Bus]), union([Hvs,Gvs,Bvs])), + %%io:format(" Gus :~p~n Bvs :~p~n Bus :~p~n Free:~p~n" ,[Gus,Bvs,Bus,Free]), + {Cs,Hvss,Frees,St4} = fun_clauses(Cs0, Vs, St3), + {[{clause,L,H,G,B}|Cs],[Hvs|Hvss],[Free|Frees],St4}; +fun_clauses([], _, St) -> {[],[],[],St}. + +%% new_fun_name(State) -> {FunName,State}. + +new_fun_name(#expand{func=F,arity=A,fcount=I}=St) -> + Name = "-" ++ atom_to_list(F) ++ "/" ++ integer_to_list(A) + ++ "-fun-" ++ integer_to_list(I) ++ "-", + {list_to_atom(Name),St#expand{fcount=I+1}}. + + +%% normalise_fields([RecDef]) -> [Field]. +%% Normalise the field definitions to always have a default value. If +%% none has been given then use 'undefined'. + +normalise_fields(Fs) -> + map(fun ({record_field,Lf,Field}) -> + {record_field,Lf,Field,{atom,Lf,undefined}}; + (F) -> F end, Fs). + +%% record_fields(RecordName, State) +%% find_field(FieldName, Fields) + +record_fields(R, St) -> dict:fetch(R, St#expand.records). + +find_field(F, [{record_field,_,{atom,_,F},Val}|_]) -> {ok,Val}; +find_field(F, [_|Fs]) -> find_field(F, Fs); +find_field(_, []) -> error. + +%% field_names(RecFields) -> [Name]. +%% Return a list of the field names structures. + +field_names(Fs) -> + map(fun ({record_field,_,Field,_Val}) -> Field end, Fs). + +%% index_expr(Line, FieldExpr, Name, Fields) -> IndexExpr. +%% Return an expression which evaluates to the index of a +%% field. Currently only handle the case where the field is an +%% atom. This expansion must be passed through expr again. + +index_expr(Line, {atom,_,F}, _Name, Fs) -> + {integer,Line,index_expr(F, Fs, 2)}. + +index_expr(F, [{record_field,_,{atom,_,F},_}|_], I) -> I; +index_expr(F, [_|Fs], I) -> + index_expr(F, Fs, I+1). + +%% pattern_fields([RecDefField], [Match]) -> [Pattern]. +%% Build a list of match patterns for the record tuple elements. +%% This expansion must be passed through pattern again. N.B. We are +%% scanning the record definition field list! + +pattern_fields(Fs, Ms) -> + Wildcard = record_wildcard_init(Ms), + map(fun ({record_field,L,{atom,_,F},_}) -> + case find_field(F, Ms) of + {ok,Match} -> Match; + error when Wildcard =:= none -> {var,L,'_'}; + error -> Wildcard + end end, + Fs). + +%% record_inits([RecDefField], [Init]) -> [InitExpr]. +%% Build a list of initialisation expressions for the record tuple +%% elements. This expansion must be passed through expr +%% again. N.B. We are scanning the record definition field list! + +record_inits(Fs, Is) -> + WildcardInit = record_wildcard_init(Is), + map(fun ({record_field,_,{atom,_,F},D}) -> + case find_field(F, Is) of + {ok,Init} -> Init; + error when WildcardInit =:= none -> D; + error -> WildcardInit + end end, + Fs). + +record_wildcard_init([{record_field,_,{var,_,'_'},D}|_]) -> D; +record_wildcard_init([_|Is]) -> record_wildcard_init(Is); +record_wildcard_init([]) -> none. + +%% record_update(Record, RecordName, [RecDefField], [Update], State) -> +%% {Expr,State'} +%% Build an expression to update fields in a record returning a new +%% record. Try to be smart and optimise this. This expansion must be +%% passed through expr again. + +record_update(R, Name, Fs, Us0, St0) -> + Line = element(2, R), + {Pre,Us,St1} = record_exprs(Us0, St0), + Nf = length(Fs), %# of record fields + Nu = length(Us), %# of update fields + Nc = Nf - Nu, %# of copy fields + + %% We need a new variable for the record expression + %% to guarantee that it is only evaluated once. + {Var,St2} = new_var(Line, St1), + + %% Try to be intelligent about which method of updating record to use. + {Update,St} = + if + Nu == 0 -> {R,St2}; %No fields updated + Nu =< Nc -> %Few fields updated + {record_setel(Var, Name, Fs, Us), St2}; + true -> %The wide area inbetween + record_match(Var, Name, Fs, Us, St2) + end, + {{block,element(2, R),Pre ++ [{match,Line,Var,R},Update]},St}. + +%% record_match(Record, RecordName, [RecDefField], [Update], State) +%% Build a 'case' expression to modify record fields. + +record_match(R, Name, Fs, Us, St0) -> + {Ps,News,St1} = record_upd_fs(Fs, Us, St0), + Lr = element(2, hd(Us)), + {{'case',Lr,R, + [{clause,Lr,[{tuple,Lr,[{atom,Lr,Name}|Ps]}],[], + [{tuple,Lr,[{atom,Lr,Name}|News]}]}, + {clause,Lr,[{var,Lr,'_'}],[], + [call_error(Lr, {tuple,Lr,[{atom,Lr,badrecord},{atom,Lr,Name}]})]} + ]}, + St1}. + +record_upd_fs([{record_field,Lf,{atom,_La,F},_Val}|Fs], Us, St0) -> + {P,St1} = new_var(Lf, St0), + {Ps,News,St2} = record_upd_fs(Fs, Us, St1), + case find_field(F, Us) of + {ok,New} -> {[P|Ps],[New|News],St2}; + error -> {[P|Ps],[P|News],St2} + end; +record_upd_fs([], _, St) -> {[],[],St}. + +%% record_setel(Record, RecordName, [RecDefField], [Update]) +%% Build a nested chain of setelement calls to build the +%% updated record tuple. + +record_setel(R, Name, Fs, Us0) -> + Us1 = foldl(fun ({record_field,Lf,Field,Val}, Acc) -> + I = index_expr(Lf, Field, Name, Fs), + [{I,Lf,Val}|Acc] + end, [], Us0), + Us = sort(Us1), + Lr = element(2, hd(Us)), + Wildcards = duplicate(length(Fs), {var,Lr,'_'}), + {'case',Lr,R, + [{clause,Lr,[{tuple,Lr,[{atom,Lr,Name}|Wildcards]}],[], + [foldr(fun ({I,Lf,Val}, Acc) -> + {call,Lf,{atom,Lf,setelement},[I,Acc,Val]} end, + R, Us)]}, + {clause,Lr,[{var,Lr,'_'}],[], + [call_error(Lr, {tuple,Lr,[{atom,Lr,badrecord},{atom,Lr,Name}]})]}]}. + +%% Expand a call to record_info/2. We have checked that it is not +%% shadowed by an import. + +record_info_call(Line, [{atom,_Li,Info},{atom,_Ln,Name}], St) -> + case Info of + size -> + {{integer,Line,1+length(record_fields(Name, St))},[],[],St}; + fields -> + {make_list(field_names(record_fields(Name, St)), Line), + [],[],St} + end. + +%% Break out expressions from an record update list and bind to new +%% variables. The idea is that we will evaluate all update expressions +%% before starting to update the record. + +record_exprs(Us, St) -> + record_exprs(Us, St, [], []). + +record_exprs([{record_field,Lf,{atom,_La,_F}=Name,Val}=Field0|Us], St0, Pre, Fs) -> + case is_simple_val(Val) of + true -> + record_exprs(Us, St0, Pre, [Field0|Fs]); + false -> + {Var,St} = new_var(Lf, St0), + Bind = {match,Lf,Var,Val}, + Field = {record_field,Lf,Name,Var}, + record_exprs(Us, St, [Bind|Pre], [Field|Fs]) + end; +record_exprs([], St, Pre, Fs) -> + {reverse(Pre),Fs,St}. + +is_simple_val({var,_,_}) -> true; +is_simple_val({atom,_,_}) -> true; +is_simple_val({integer,_,_}) -> true; +is_simple_val({float,_,_}) -> true; +is_simple_val({nil,_}) -> true; +is_simple_val(_) -> false. + +%% pattern_bin([Element], State) -> {[Element],[Variable],[UsedVar],State}. + +pattern_bin(Es0, St) -> + Es1 = bin_expand_strings(Es0), + foldr(fun (E, Acc) -> pattern_element(E, Acc) end, {[],[],[],St}, Es1). + +pattern_element({bin_element,Line,Expr,Size,Type}, {Es,Esvs,Esus,St0}) -> + {Expr1,Vs1,Us1,St1} = pattern(Expr, St0), + {Size1,Vs2,Us2,St2} = pat_bit_size(Size, St1), + {Size2,Type1} = make_bit_type(Line, Size1,Type), + {[{bin_element,Line,Expr1,Size2,Type1}|Es], + union([Vs1,Vs2,Esvs]),union([Us1,Us2,Esus]),St2}. + +pat_bit_size(default, St) -> {default,[],[],St}; +pat_bit_size({atom,_La,all}=All, St) -> {All,[],[],St}; +pat_bit_size({var,_Lv,V}=Var, St) -> {Var,[],[V],St}; +pat_bit_size(Size, St) -> + Line = element(2, Size), + {value,Sz,_} = erl_eval:expr(Size, erl_eval:new_bindings()), + {{integer,Line,Sz},[],[],St}. + +make_bit_type(Line, default, Type0) -> + case erl_bits:set_bit_type(default, Type0) of + {ok,all,Bt} -> {{atom,Line,all},erl_bits:as_list(Bt)}; + {ok,Size,Bt} -> {{integer,Line,Size},erl_bits:as_list(Bt)} + end; +make_bit_type(_Line, Size, Type0) -> %Integer or 'all' + {ok,Size,Bt} = erl_bits:set_bit_type(Size, Type0), + {Size,erl_bits:as_list(Bt)}. + +%% expr_bin([Element], [VisibleVar], State) -> +%% {[Element],[NewVar],[UsedVar],State}. + +expr_bin(Es0, Vs, St) -> + Es1 = bin_expand_strings(Es0), + foldr(fun (E, Acc) -> bin_element(E, Vs, Acc) end, {[],[],[],St}, Es1). + +bin_element({bin_element,Line,Expr,Size,Type}, Vs, {Es,Esvs,Esus,St0}) -> + {Expr1,Vs1,Us1,St1} = expr(Expr, Vs, St0), + {Size1,Vs2,Us2,St2} = if Size == default -> {default,[],[],St1}; + true -> expr(Size, Vs, St1) + end, + {Size2,Type1} = make_bit_type(Line, Size1, Type), + {[{bin_element,Line,Expr1,Size2,Type1}|Es], + union([Vs1,Vs2,Esvs]),union([Us1,Us2,Esus]),St2}. + +bin_expand_strings(Es) -> + foldr(fun ({bin_element,Line,{string,_,S},default,default}, Es1) -> + foldr(fun (C, Es2) -> + [{bin_element,Line,{char,Line,C},default,default}|Es2] + end, Es1, S); + (E, Es1) -> [E|Es1] + end, [], Es). + +%% new_var_name(State) -> {VarName,State}. + +new_var_name(St) -> + C = St#expand.vcount, + {list_to_atom("pre" ++ integer_to_list(C)),St#expand{vcount=C+1}}. + +%% new_var(Line, State) -> {Var,State}. + +new_var(L, St0) -> + {New,St1} = new_var_name(St0), + {{var,L,New},St1}. + +%% new_vars(Count, Line, State) -> {[Var],State}. +%% Make Count new variables. + +new_vars(N, L, St) -> new_vars(N, L, St, []). + +new_vars(N, L, St0, Vs) when N > 0 -> + {V,St1} = new_var(L, St0), + new_vars(N-1, L, St1, [V|Vs]); +new_vars(0, _L, St, Vs) -> {Vs,St}. + +%% make_list(TermList, Line) -> ConsTerm. + +make_list(Ts, Line) -> + foldr(fun (H, T) -> {cons,Line,H,T} end, {nil,Line}, Ts). + +string_to_conses(Line, Cs, Tail) -> + foldr(fun (C, T) -> {cons,Line,{char,Line,C},T} end, Tail, Cs). + + +%% In syntax trees, module/package names are atoms or lists of atoms. + +package_to_string(A) when atom(A) -> atom_to_list(A); +package_to_string(L) when list(L) -> packages:concat(L). + +expand_package({atom,L,A} = M, St) -> + case dict:find(A, St#expand.mod_imports) of + {ok, A1} -> + {atom,L,A1}; + error -> + case packages:is_segmented(A) of + true -> + M; + false -> + M1 = packages:concat(St#expand.package, A), + {atom,L,list_to_atom(M1)} + end + end; +expand_package(M, _St) -> + case erl_parse:package_segments(M) of + error -> + M; + M1 -> + {atom,element(2,M),list_to_atom(package_to_string(M1))} + end. + +%% Create a case-switch on true/false, generating badarg for all other +%% values. + +make_bool_switch(L, E, V, T, F) -> + make_bool_switch_1(L, E, V, [T], [F]). + +make_bool_switch_1(L, E, V, T, F) -> + case get(sys_pre_expand_in_guard) of + undefined -> make_bool_switch_body(L, E, V, T, F); + yes -> make_bool_switch_guard(L, E, V, T, F) + end. + +make_bool_switch_guard(_, E, _, [{atom,_,true}], [{atom,_,false}]) -> E; +make_bool_switch_guard(L, E, V, T, F) -> + NegL = -abs(L), + {'case',NegL,E, + [{clause,NegL,[{atom,NegL,true}],[],T}, + {clause,NegL,[{atom,NegL,false}],[],F}, + {clause,NegL,[V],[],[V]} + ]}. + +make_bool_switch_body(L, E, V, T, F) -> + NegL = -abs(L), + {'case',NegL,E, + [{clause,NegL,[{atom,NegL,true}],[],T}, + {clause,NegL,[{atom,NegL,false}],[],F}, + {clause,NegL,[V],[], + [call_error(NegL,{tuple,NegL,[{atom,NegL,badarg},V]})]} + ]}. + +%% Expand a list of cond-clauses to a sequence of case-switches. + +cond_clauses([{clause,L,[],[[E]],B}],V) -> + make_bool_switch_1(L,E,V,B,[call_error(L,{atom,L,cond_clause})]); +cond_clauses([{clause,L,[],[[E]],B} | Cs],V) -> + make_bool_switch_1(L,E,V,B,[cond_clauses(Cs,V)]). + +%% call_error(Line, Reason) -> Expr. +%% Build a call to erlang:error/1 with reason Reason. + +call_error(L, R) -> + {call,L,{remote,L,{atom,L,erlang},{atom,L,error}},[R]}. + +%% new_in_all(Before, RegionList) -> NewInAll +%% Return the variables new in all clauses. + +new_in_all(Before, Region) -> + InAll = intersection(Region), + subtract(InAll, Before). + +%% import(Line, Imports, State) -> +%% State' +%% imported(Name, Arity, State) -> +%% {yes,Module} | no +%% Handle import declarations and est for imported functions. No need to +%% check when building imports as code is correct. + +import({Mod0,Fs}, St) -> + Mod = list_to_atom(package_to_string(Mod0)), + Mfs = from_list(Fs), + St#expand{imports=add_imports(Mod, Mfs, St#expand.imports)}; +import(Mod0, St) -> + Mod = package_to_string(Mod0), + Key = list_to_atom(packages:last(Mod)), + St#expand{mod_imports=dict:store(Key, list_to_atom(Mod), + St#expand.mod_imports)}. + +add_imports(Mod, [F|Fs], Is) -> + add_imports(Mod, Fs, orddict:store(F, Mod, Is)); +add_imports(_, [], Is) -> Is. + +imported(F, A, St) -> + case orddict:find({F,A}, St#expand.imports) of + {ok,Mod} -> {yes,Mod}; + error -> no + end. |