epp.erl

来自「OTP是开放电信平台的简称」· ERL 代码 · 共 991 行 · 第 1/3 页

skip_toks(From, St, [I|Sis]) ->
    case io:scan_erl_form(St#epp.file, '', St#epp.line) of
	{ok,[{'-',_Lh},{atom,_Li,ifdef}|_Toks],Cl} ->
	    skip_toks(From, St#epp{line=Cl}, [ifdef,I|Sis]);
	{ok,[{'-',_Lh},{atom,_Li,ifndef}|_Toks],Cl} ->
	    skip_toks(From, St#epp{line=Cl}, [ifndef,I|Sis]);
	{ok,[{'-',_Lh},{atom,_Li,'if'}|_Toks],Cl} ->
	    skip_toks(From, St#epp{line=Cl}, ['if',I|Sis]);
	{ok,[{'-',_Lh},{atom,Le,else}|_Toks],Cl}->
	    skip_else(Le, From, St#epp{line=Cl}, [I|Sis]);
	{ok,[{'-',_Lh},{atom,_Le,endif}|_Toks],Cl} ->
	    skip_toks(From, St#epp{line=Cl}, Sis);
	{ok,_Toks,Cl} ->
	    skip_toks(From, St#epp{line=Cl}, [I|Sis]);
	{error,_E,Cl} ->
	    skip_toks(From, St#epp{line=Cl}, [I|Sis]);
	{eof,Cl} ->
	    leave_file(From, St#epp{line=Cl,istk=[I|Sis]});
	{error,_E} ->
            epp_reply(From, {error,{St#epp.line,epp,cannot_parse}}),
	    leave_file(From, St)		%This serious, just exit!
    end;
skip_toks(From, St, []) ->
    scan_toks(From, St).

skip_else(Le, From, St, [else|Sis]) ->
    epp_reply(From, {error,{Le,epp,{illegal,"repeated",else}}}),
    wait_req_skip(St, [else|Sis]);
skip_else(_Le, From, St, [_I]) ->
    scan_toks (From, St#epp{istk=[else|St#epp.istk]});
skip_else(_Le, From, St, Sis) ->
    skip_toks(From, St, Sis).

%% macro_pars(Tokens, ArgStack)
%% macro_expansion(Tokens)
%%  Extract the macro parameters and the expansion from a macro definition.

macro_pars([{')',_Lp}, {',',_Ld}|Ex], Args) ->
    {ok, {lists:reverse(Args), macro_expansion(Ex)}};
macro_pars([{var,_,Name}, {')',_Lp}, {',',_Ld}|Ex], Args) ->
    false = lists:member(Name, Args),		%Prolog is nice
    {ok, {lists:reverse([Name|Args]), macro_expansion(Ex)}};
macro_pars([{var,_L,Name}, {',',_}|Ts], Args) ->
    false = lists:member(Name, Args),           
    macro_pars(Ts, [Name|Args]).

macro_expansion([{')',_Lp},{dot,_Ld}]) -> [];
macro_expansion([{dot,_Ld}]) -> [];		%Be nice, allow no right paren!
macro_expansion([T|Ts]) ->
    [T|macro_expansion(Ts)].

%% expand_macros(Tokens, Macros)
%% expand_macro(Tokens, MacroLine, RestTokens)
%%  Expand the macros in a list of tokens, making sure that an expansion
%%  gets the same line number as the macro call.

expand_macros(Type, Lm, M, Toks, Ms0) ->
    %% (Type will always be 'atom')
    {Ms, U} = Ms0,
    check_uses([{Type,M}], [], U, Lm),
    case dict:find({Type,M}, Ms) of
	{ok,{none,Exp}} ->
	    expand_macros(expand_macro(Exp, Lm, Toks, dict:new()), Ms0);
	{ok,{As,Exp}} ->
	    {Bs,Toks1} = bind_args(Toks, Lm, M, As, dict:new()),
	    %%io:format("Bound arguments to macro ~w (~w)~n", [M,Bs]),
	    expand_macros(expand_macro(Exp, Lm, Toks1, Bs), Ms0);
	{ok,undefined} ->
	    throw({error,Lm,{undefined,M}});
	error ->
	    throw({error,Lm,{undefined,M}})
    end.

check_uses(undefined, _Anc, _U, _Lm) ->
    ok;
check_uses([], _Anc, _U, _Lm) ->
    ok;
check_uses([M|Rest], Anc, U, Lm) ->
    case lists:member(M, Anc) of
	true ->
	    {_, Name} = M,
	    throw({error,Lm,{circular,Name}});
	false ->
	    L = get_macro_uses(M, U),
	    check_uses(L, [M|Anc], U, Lm),
	    check_uses(Rest, Anc, U, Lm)
    end.
    
get_macro_uses(M, U) ->
    case dict:find(M, U) of
	error ->
	    [];
	{ok, L} ->
	    L
    end.

%% Macro expansion
expand_macros([{'?',_Lq},{atom,Lm,M}|Toks], Ms) ->
    expand_macros(atom, Lm, M, Toks, Ms);
%% Special macros
expand_macros([{'?',_Lq},{var,Lm,'LINE'}|Toks], Ms) ->
    [{integer,Lm,Lm}|expand_macros(Toks, Ms)];
expand_macros([{'?',_Lq},{var,Lm,M}|Toks], Ms) ->
    expand_macros(atom, Lm, M, Toks, Ms);
%% Illegal macros
expand_macros([{'?',_Lq},{Type,Lt}|_Toks], _Ms) ->
    throw({error,Lt,{call,[$?|atom_to_list(Type)]}});
expand_macros([{'?',_Lq},{_Type,Lt,What}|_Toks], _Ms) ->
    throw({error,Lt,{call,[$?|io_lib:write(What)]}});

expand_macros([T|Ts], Ms) ->
    [T|expand_macros(Ts, Ms)];
expand_macros([], _Ms) -> [].

%% bind_args(Tokens, MacroLine, MacroName, ArgumentVars, Bindings)
%%  Collect the arguments to a macro call and check for correct number.

bind_args([{'(',_Llp},{')',_Lrp}|Toks], _Lm, _M, [], Bs) ->
    {Bs,Toks};
bind_args([{'(',_Llp}|Toks0], Lm, M, [A|As], Bs) ->
    {Arg,Toks1} = macro_arg(Toks0, [], []),
    macro_args(Toks1, Lm, M, As, dict:store(A, Arg, Bs));
bind_args(_Toks, Lm, M, _As, _Bs) ->
    throw({error,Lm,{mismatch,M}}).

macro_args([{')',_Lrp}|Toks], _Lm, _M, [], Bs) ->
    {Bs,Toks};
macro_args([{',',_Lc}|Toks0], Lm, M, [A|As], Bs) ->
    {Arg,Toks1} = macro_arg(Toks0, [], []),
    macro_args(Toks1, Lm, M, As, dict:store(A, Arg, Bs));
macro_args([], Lm, M, _As, _Bs) ->
    throw({error,Lm,{arg_error,M}});
macro_args(_Toks, Lm, M, _As, _Bs) ->
    throw({error,Lm,{mismatch,M}}).

%% macro_arg([Tok], [ClosePar], [ArgTok]) -> {[ArgTok],[RestTok]}.
%%  Collect argument tokens until we hit a ',' or a ')'. We know a
%%  enough about syntax to recognise "open parentheses" and keep
%%  scanning until matching "close parenthesis".

macro_arg([{',',Lc}|Toks], [], Arg) ->
    {lists:reverse(Arg),[{',',Lc}|Toks]};
macro_arg([{')',Lrp}|Toks], [], Arg) ->
    {lists:reverse(Arg),[{')',Lrp}|Toks]};
macro_arg([{'(',Llp}|Toks], E, Arg) ->
    macro_arg(Toks, [')'|E], [{'(',Llp}|Arg]);
macro_arg([{'<<',Lls}|Toks], E, Arg) ->
    macro_arg(Toks, ['>>'|E], [{'<<',Lls}|Arg]);
macro_arg([{'[',Lls}|Toks], E, Arg) ->
    macro_arg(Toks, [']'|E], [{'[',Lls}|Arg]);
macro_arg([{'{',Llc}|Toks], E, Arg) ->
    macro_arg(Toks, ['}'|E], [{'{',Llc}|Arg]);
macro_arg([{'begin',Lb}|Toks], E, Arg) ->
    macro_arg(Toks, ['end'|E], [{'begin',Lb}|Arg]);
macro_arg([{'if',Li}|Toks], E, Arg) ->
    macro_arg(Toks, ['end'|E], [{'if',Li}|Arg]);
macro_arg([{'case',Lc}|Toks], E, Arg) ->
    macro_arg(Toks, ['end'|E], [{'case',Lc}|Arg]);
macro_arg([{'receive',Lr}|Toks], E, Arg) ->
    macro_arg(Toks, ['end'|E], [{'receive',Lr}|Arg]);
macro_arg([{'try',Lr}|Toks], E, Arg) ->
    macro_arg(Toks, ['end'|E], [{'try',Lr}|Arg]);
macro_arg([{'cond',Lr}|Toks], E, Arg) ->
    macro_arg(Toks, ['end'|E], [{'cond',Lr}|Arg]);
macro_arg([{Rb,Lrb}|Toks], [Rb|E], Arg) ->	%Found matching close
    macro_arg(Toks, E, [{Rb,Lrb}|Arg]);
macro_arg([T|Toks], E, Arg) ->
    macro_arg(Toks, E, [T|Arg]);
macro_arg([], _E, Arg) ->
    {lists:reverse(Arg),[]}.

%% expand_macro(MacroDef, MacroLine, RestTokens, Bindings)
%% expand_arg(Argtokens, MacroTokens, MacroLine, RestTokens, Bindings)
%%  Insert the macro expansion replacing macro parameters with their
%%  argument values, inserting the line number of first the macro call
%%  and then the macro arguments, i.e. simulate textual expansion.

expand_macro([{var,_Lv,V}|Ts], L, Rest, Bs) ->
    case dict:find(V, Bs) of
	{ok,Val} ->
	    %% lists:append(Val, expand_macro(Ts, L, Rest, Bs));
	    expand_arg(Val, Ts, L, Rest, Bs);
	error ->
	    [{var,L,V}|expand_macro(Ts, L, Rest, Bs)]
    end;
expand_macro([{'?', _}, {'?', _}, {var,_Lv,V}|Ts], L, Rest, Bs) ->
    case dict:find(V, Bs) of
	{ok,Val} ->
	    %% lists:append(Val, expand_macro(Ts, L, Rest, Bs));
	    expand_arg(stringify(Val), Ts, L, Rest, Bs);
	error ->
	    [{var,L,V}|expand_macro(Ts, L, Rest, Bs)]
    end;
expand_macro([T|Ts], L, Rest, Bs) ->
    [setelement(2, T, L)|expand_macro(Ts, L, Rest, Bs)];
expand_macro([], _L, Rest, _Bs) -> Rest.

expand_arg([A|As], Ts, _L, Rest, Bs) ->
    [A|expand_arg(As, Ts, element(2, A), Rest, Bs)];
expand_arg([], Ts, L, Rest, Bs) ->
    expand_macro(Ts, L, Rest, Bs).

%%% stringify(L) returns a list of one token: a string which when
%%% tokenized would yield the token list L.

%tst(Str) ->
%    {ok, T, _} = erl_scan:string(Str),
%    [{string, _, S}] = stringify(T),
%    S.

token_src({dot, _}) ->
    ".";
token_src({X, _}) when is_atom(X) ->
    atom_to_list(X);
token_src({var, _, X}) ->
    atom_to_list(X);
token_src({string, _, X}) ->
    lists:flatten(io_lib:format("~p", [X]));
token_src({_, _, X}) ->
    lists:flatten(io_lib:format("~w", [X])).

stringify1([]) ->
    [];
stringify1([T | Tokens]) ->
    [io_lib:format(" ~s", [token_src(T)]) | stringify1(Tokens)].

stringify(L) ->
    [$\s | S] = lists:flatten(stringify1(L)),
    [{string, 1, S}].

%% epp_request(Epp)
%% epp_request(Epp, Request)
%% epp_reply(From, Reply)
%%  Handle communication with the epp.

epp_request(Epp) ->
    wait_epp_reply(Epp, erlang:monitor(process, Epp)).

epp_request(Epp, Req) ->
    Epp ! {epp_request,self(),Req},
    wait_epp_reply(Epp, erlang:monitor(process, Epp)).

epp_reply(From, Rep) ->
    From ! {epp_reply,self(),Rep}.

wait_epp_reply(Epp, Mref) ->
    receive
	{epp_reply,Epp,Rep} -> 
	    erlang:demonitor(Mref),
	    receive {'DOWN',Mref,_,_,_} -> ok after 0 -> ok end,
	    Rep;
	{'DOWN',Mref,_,_,E} -> 
	    receive {epp_reply,Epp,Rep} -> Rep
	    after 0 -> exit(E)
	    end
    end.

expand_var([$$ | _] = NewName) ->
    case catch expand_var1(NewName) of
	{ok, ExpName} ->
	    ExpName;
	_ ->
	    NewName
    end;
expand_var(NewName) ->
    NewName.

expand_var1(NewName) ->
    [[$$ | Var] | Rest] = filename:split(NewName),
    Value = os:getenv(Var),
    true = Value =/= false,
    {ok, filename:join([Value | Rest])}.

%% epp has always output -file attributes when entering and leaving
%% included files (-include, -include_lib). Starting with R11B the
%% -file attribute is also recognized in the input file. This is
%% mainly aimed at yecc, the parser generator, which uses the -file
%% attribute to get correct lines in messages referring to code
%% supplied by the user (actions etc in .yrl files).
%% 
%% In a perfect world (read: perfectly implemented applications such
%% as Xref, Cover, Debugger, etc.) it would not be necessary to
%% distinguish -file attributes from epp and the input file. The
%% Debugger for example could have one window for each referred file,
%% each window with its own set of breakpoints etc. The line numbers
%% of the abstract code would then point into different windows
%% depending on the -file attribute. [Note that if, as is the case for
%% yecc, code has been copied into the file, then it is possible that
%% the copied code differ from the one referred to by the -file
%% attribute, which means that line numbers can mismatch.] In practice
%% however it is very rare with Erlang functions in included files, so
%% only one window is used per module. This means that the line
%% numbers of the abstract code have to be adjusted to refer to the
%% top-most source file. The function interpret_file_attributes/1
%% below interprets the -file attribute and returns forms where line
%% numbers refer to the top-most file. The -file attribute forms that
%% have been output by epp (corresponding to -include and
%% -include_lib) are kept, but the user's -file attributes are
%% removed. This seems sufficient for now.
%% 
%% It turns out to be difficult to distinguish -file attributes in the
%% input file from the ones added by epp unless some action is taken.
%% The (less than perfect) solution employed is to let epp assign
%% negative line number to user supplied -file attributes.

interpret_file_attribute(Forms) ->
    interpret_file_attr(Forms, 0, []).

interpret_file_attr([{attribute,L,file,{_File,Line}} | Forms], 
                    Delta, Fs) when L < 0 ->
    %% -file attribute
    interpret_file_attr(Forms, (abs(L) + Delta) - Line, Fs);
interpret_file_attr([{attribute,_AL,file,{File,_Line}}=Form | Forms], 
                    Delta, Fs) ->
    %% -include or -include_lib
    % true = _AL =:= _Line,
    case Fs of
        [_, Delta1, File | Fs1] -> % end of included file
            [Form | interpret_file_attr(Forms, Delta1, [File | Fs1])];
        _ -> % start of included file
            [Form | interpret_file_attr(Forms, 0, [File, Delta | Fs])]
    end;
interpret_file_attr([Form0 | Forms], Delta, Fs) ->
    Form = erl_lint:modify_line(Form0, fun(L) -> abs(L) + Delta end),
    [Form | interpret_file_attr(Forms, Delta, Fs)];
interpret_file_attr([], _Delta, _Fs) ->
    [].