顺其自然

expand_opt(basic_validation, Os) ->
    [no_code_generation,to_pp,binary|Os];
expand_opt(strong_validation, Os) ->
    [no_code_generation,to_kernel,binary|Os];
expand_opt(report, Os) ->
    [report_errors,report_warnings|Os];
expand_opt(return, Os) ->
    [return_errors,return_warnings|Os];
expand_opt(r10, Os) ->
    [no_stack_trimming,no_topt,no_binaries,no_gc_bifs,no_constant_pool|Os];
expand_opt(r11, Os) ->
    [no_stack_trimming,no_binaries,no_constant_pool|Os];
expand_opt({debug_info_key,_}=O, Os) ->
    [encrypt_debug_info,O|Os];
expand_opt(no_binaries=O, Os) ->
    %%Turn off the entire type optimization pass.
    [no_topt,O|Os];
expand_opt(no_float_opt, Os) ->
    %%Turn off the entire type optimization pass.
    [no_topt|Os];
expand_opt(O, Os) -> [O|Os].

sub_scan_escape([O1,O2,O3|Cs], [Fun|Stack], Toks, Pos, State, Errors) 
  when O1 >= $0, O1 =< $7, O2 >= $0, O2 =< $7, O3 >= $0, O3 =< $7 ->
    Val = (O1*8 + O2)*8 + O3 - 73*$0,
    Fun([Val|Cs], Stack, Toks, Pos, State, Errors);
sub_scan_escape([O1,O2]=Cs, Stack, Toks, Pos, State, Errors) 
  when O1 >= $0, O1 =< $7, O2 >= $0, O2 =< $7 ->
    more(Cs, Stack, Toks, Pos, State, Errors, fun sub_scan_escape/6);
sub_scan_escape([O1,O2|Cs], [Fun|Stack], Toks, Pos, State, Errors) 
  when O1 >= $0, O1 =< $7, O2 >= $0, O2 =< $7 ->
    Val = (O1*8 + O2) - 9*$0,
    Fun([Val|Cs], Stack, Toks, Pos, State, Errors);
sub_scan_escape([O1]=Cs, Stack, Toks, Pos, State, Errors) 
  when O1 >= $0, O1 =< $7 ->
    more(Cs, Stack, Toks, Pos, State, Errors, fun sub_scan_escape/6);
sub_scan_escape([O1|Cs], [Fun|Stack], Toks, Pos, State, Errors) 
  when O1 >= $0, O1 =< $7 ->
    Val = O1 - $0,
    Fun([Val|Cs], Stack, Toks, Pos, State, Errors);
%% \^X -> CTL-X
sub_scan_escape([$^,C|Cs], [Fun|Stack], Toks, Pos, State, Errors) ->
    Val = C band 31,
    Fun([Val|Cs], Stack, Toks, Pos, State, Errors);
sub_scan_escape([$^]=Cs, Stack, Toks, Pos, State, Errors) ->
    more(Cs, Stack, Toks, Pos, State, Errors, fun sub_scan_escape/6);
sub_scan_escape([$^|Eof], [Fun|Stack], Toks, Pos, State, Errors) ->
    Fun(Eof, Stack, Toks, Pos, State, Errors);
%% \NL (backslash newline)
sub_scan_escape([$\n|Cs],[Fun|Stack], Toks, Pos, State, Errors) ->
    Fun([nl|Cs], Stack, Toks, Pos, State, Errors);
%% \X - familiar escape sequences
sub_scan_escape([C|Cs], [Fun|Stack], Toks, Pos, State, Errors) ->
    Val = escape_char(C),
    Fun([Val|Cs], Stack, Toks, Pos, State, Errors);
%%
sub_scan_escape([], Stack, Toks, Pos, State, Errors) ->
    more([], Stack, Toks, Pos, State, Errors, fun sub_scan_escape/6);
sub_scan_escape(Eof, [Fun|Stack], Toks, Pos, State, Errors) ->
    Fun(Eof, Stack, Toks, Pos, State, Errors).

find_user_code(ParseActions, St) ->
    [#user_code{state = State, 
                terminal = Terminal, 
                funname = inlined_function_name(State, Terminal), 
                action = Action} || 
        {State, La_actions} <- ParseActions,
        {Action, Terminals, RuleNmbr, NmbrOfDaughters} 
            <- find_user_code2(La_actions),
        case tokens(RuleNmbr, St) of
            [{var, _, '__1'}] -> NmbrOfDaughters =/= 1;
            _ -> true
        end,
        Terminal <- Terminals].

gexpr_test({atom,L,true}, Bools, St0) ->
    {#c_literal{anno=lineno_anno(L, St0),val=true},[],Bools,St0};
gexpr_test({atom,L,false}, Bools, St0) ->
    {#c_literal{anno=lineno_anno(L, St0),val=false},[],Bools,St0};
gexpr_test(E0, Bools0, St0) ->
    {E1,Eps0,St1} = expr(E0, St0),
    %% Generate "top-level" test and argument calls.
    case E1 of
	#icall{anno=Anno,module=#c_literal{val=erlang},name=#c_literal{val=N},args=As} ->
	    Ar = length(As),
	    case erl_internal:type_test(N, Ar) orelse
		erl_internal:comp_op(N, Ar) of
		true -> {E1,Eps0,Bools0,St1};
		false ->
		    Lanno = Anno#a.anno,
		    {New,St2} = new_var(Lanno, St1),
		    Bools = [New|Bools0],
		    {#icall{anno=Anno,	%Must have an #a{}
			    module=#c_literal{anno=Lanno,val=erlang},
			    name=#c_literal{anno=Lanno,val='=:='},
			    args=[New,#c_literal{anno=Lanno,val=true}]},
		     Eps0 ++ [#iset{anno=Anno,var=New,arg=E1}],Bools,St2}
	    end;
	_ ->
	    Anno = get_ianno(E1),
	    Lanno = get_lineno_anno(E1),
	    case core_lib:is_simple(E1) of
		true ->
		    Bools = [E1|Bools0],
		    {#icall{anno=Anno,	%Must have an #a{}
			    module=#c_literal{anno=Lanno,val=erlang},
			    name=#c_literal{anno=Lanno,val='=:='},
			    args=[E1,#c_literal{anno=Lanno,val=true}]},Eps0,Bools,St1};
		false ->
		    {New,St2} = new_var(Lanno, St1),
		    Bools = [New|Bools0],
		    {#icall{anno=Anno,	%Must have an #a{}
			    module=#c_literal{anno=Lanno,val=erlang},
			    name=#c_literal{anno=Lanno,val='=:='},
			    args=[New,#c_literal{anno=Lanno,val=true}]},
		     Eps0 ++ [#iset{anno=Anno,var=New,arg=E1}],Bools,St2}
	    end
    end.

-module(record_test).
-export([test/0]).
-record(rec,{f1,f2}).

test()->
Rec2=#rec{f1=2,f2=3},
test2(Rec2),
io:fwrite("Rec2=~p ~n",[Rec2]),

F1=2,
F2=ets:new(rec_f2, [set]),
Rec3 = #rec{f1 =F1, f2=F2},
ets:insert(Rec3#rec.f2, {10}),
io:fwrite("Rec3#rec.f2=~p ~n",[ets:tab2list(Rec3#rec.f2)]),
test3(Rec3),
io:fwrite("Rec3#rec.f2=~p ~n",[ets:tab2list(Rec3#rec.f2)]),
io:fwrite("Rec3=~p ~n",[Rec3]).

test2(Rec)->
Rec#rec{f1=20,f2=30}.

test3(Rec)->
Rec#rec{f1=20,f2=ets:insert(Rec#rec.f2, {30})}.