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-rw-r--r--lib/stdlib/src/epp.erl152
1 files changed, 133 insertions, 19 deletions
diff --git a/lib/stdlib/src/epp.erl b/lib/stdlib/src/epp.erl
index be7c2ec346..936c095aef 100644
--- a/lib/stdlib/src/epp.erl
+++ b/lib/stdlib/src/epp.erl
@@ -46,6 +46,10 @@
-type tokens() :: [erl_scan:token()].
-type used() :: {name(), argspec()}.
+-type function_name_type() :: 'undefined'
+ | {atom(),non_neg_integer()}
+ | tokens().
+
-define(DEFAULT_ENCODING, utf8).
%% Epp state record.
@@ -63,7 +67,8 @@
uses = #{} %Macro use structure
:: #{name() => [{argspec(), [used()]}]},
default_encoding = ?DEFAULT_ENCODING :: source_encoding(),
- pre_opened = false :: boolean()
+ pre_opened = false :: boolean(),
+ fname = [] :: function_name_type()
}).
%% open(Options)
@@ -205,6 +210,10 @@ format_error({include,W,F}) ->
io_lib:format("can't find include ~s \"~s\"", [W,F]);
format_error({illegal,How,What}) ->
io_lib:format("~s '-~s'", [How,What]);
+format_error({illegal_function,Macro}) ->
+ io_lib:format("?~s can only be used within a function", [Macro]);
+format_error({illegal_function_usage,Macro}) ->
+ io_lib:format("?~s must not begin a form", [Macro]);
format_error({'NYI',What}) ->
io_lib:format("not yet implemented '~s'", [What]);
format_error(E) -> file:format_error(E).
@@ -545,6 +554,8 @@ predef_macros(File) ->
Machine = list_to_atom(erlang:system_info(machine)),
Anno = line1(),
Defs = [{'FILE', {none,[{string,Anno,File}]}},
+ {'FUNCTION_NAME', undefined},
+ {'FUNCTION_ARITY', undefined},
{'LINE', {none,[{integer,Anno,1}]}},
{'MODULE', undefined},
{'MODULE_STRING', undefined},
@@ -755,7 +766,7 @@ scan_toks([{'-',_Lh},{atom,_Le,elif}=Elif|Toks], From, St) ->
scan_toks([{'-',_Lh},{atom,_Le,endif}=Endif|Toks], From, St) ->
scan_endif(Toks, Endif, From, St);
scan_toks([{'-',_Lh},{atom,_Lf,file}=FileToken|Toks0], From, St) ->
- case catch expand_macros(Toks0, {St#epp.macs, St#epp.uses}) of
+ case catch expand_macros(Toks0, St) of
Toks1 when is_list(Toks1) ->
scan_file(Toks1, FileToken, From, St);
{error,ErrL,What} ->
@@ -763,7 +774,7 @@ scan_toks([{'-',_Lh},{atom,_Lf,file}=FileToken|Toks0], From, St) ->
wait_req_scan(St)
end;
scan_toks(Toks0, From, St) ->
- case catch expand_macros(Toks0, {St#epp.macs, St#epp.uses}) of
+ case catch expand_macros(Toks0, St#epp{fname=Toks0}) of
Toks1 when is_list(Toks1) ->
epp_reply(From, {ok,Toks1}),
wait_req_scan(St#epp{macs=scan_module(Toks1, St#epp.macs)});
@@ -1145,24 +1156,24 @@ macro_expansion([T|Ts], _Anno0) ->
[T|macro_expansion(Ts, T)];
macro_expansion([], Anno0) -> throw({error,loc(Anno0),premature_end}).
-%% expand_macros(Tokens, Macros)
+%% expand_macros(Tokens, St)
%% expand_macro(Tokens, MacroToken, RestTokens)
%% Expand the macros in a list of tokens, making sure that an expansion
%% gets the same location as the macro call.
-expand_macros(MacT, M, Toks, Ms0) ->
- {Ms,U} = Ms0,
+expand_macros(MacT, M, Toks, St) ->
+ #epp{macs=Ms,uses=U} = St,
Lm = loc(MacT),
Tinfo = element(2, MacT),
case expand_macro1(Lm, M, Toks, Ms) of
{ok,{none,Exp}} ->
check_uses([{M,none}], [], U, Lm),
- Toks1 = expand_macros(expand_macro(Exp, Tinfo, [], #{}), Ms0),
- expand_macros(Toks1++Toks, Ms0);
+ Toks1 = expand_macros(expand_macro(Exp, Tinfo, [], #{}), St),
+ expand_macros(Toks1++Toks, St);
{ok,{As,Exp}} ->
check_uses([{M,length(As)}], [], U, Lm),
{Bs,Toks1} = bind_args(Toks, Lm, M, As, #{}),
- expand_macros(expand_macro(Exp, Tinfo, Toks1, Bs), Ms0)
+ expand_macros(expand_macro(Exp, Tinfo, Toks1, Bs), St)
end.
expand_macro1(Lm, M, Toks, Ms) ->
@@ -1211,16 +1222,32 @@ get_macro_uses({M,Arity}, U) ->
%% Macro expansion
%% Note: io:scan_erl_form() does not return comments or white spaces.
-expand_macros([{'?',_Lq},{atom,_Lm,M}=MacT|Toks], Ms) ->
- expand_macros(MacT, M, Toks, Ms);
+expand_macros([{'?',_Lq},{atom,_Lm,M}=MacT|Toks], St) ->
+ expand_macros(MacT, M, Toks, St);
%% Special macros
-expand_macros([{'?',_Lq},{var,Lm,'LINE'}=Tok|Toks], Ms) ->
+expand_macros([{'?',_Lq},{var,Lm,'FUNCTION_NAME'}=Token|Toks], St0) ->
+ St = update_fun_name(Token, St0),
+ case St#epp.fname of
+ undefined ->
+ [{'?',_Lq},Token];
+ {Name,_} ->
+ [{atom,Lm,Name}]
+ end ++ expand_macros(Toks, St);
+expand_macros([{'?',_Lq},{var,Lm,'FUNCTION_ARITY'}=Token|Toks], St0) ->
+ St = update_fun_name(Token, St0),
+ case St#epp.fname of
+ undefined ->
+ [{'?',_Lq},Token];
+ {_,Arity} ->
+ [{integer,Lm,Arity}]
+ end ++ expand_macros(Toks, St);
+expand_macros([{'?',_Lq},{var,Lm,'LINE'}=Tok|Toks], St) ->
Line = erl_scan:line(Tok),
- [{integer,Lm,Line}|expand_macros(Toks, Ms)];
-expand_macros([{'?',_Lq},{var,_Lm,M}=MacT|Toks], Ms) ->
- expand_macros(MacT, M, Toks, Ms);
+ [{integer,Lm,Line}|expand_macros(Toks, St)];
+expand_macros([{'?',_Lq},{var,_Lm,M}=MacT|Toks], St) ->
+ expand_macros(MacT, M, Toks, St);
%% Illegal macros
-expand_macros([{'?',_Lq},Token|_Toks], _Ms) ->
+expand_macros([{'?',_Lq},Token|_Toks], _St) ->
T = case erl_scan:text(Token) of
Text when is_list(Text) ->
Text;
@@ -1229,9 +1256,9 @@ expand_macros([{'?',_Lq},Token|_Toks], _Ms) ->
io_lib:write(Symbol)
end,
throw({error,loc(Token),{call,[$?|T]}});
-expand_macros([T|Ts], Ms) ->
- [T|expand_macros(Ts, Ms)];
-expand_macros([], _Ms) -> [].
+expand_macros([T|Ts], St) ->
+ [T|expand_macros(Ts, St)];
+expand_macros([], _St) -> [].
%% bind_args(Tokens, MacroLocation, MacroName, ArgumentVars, Bindings)
%% Collect the arguments to a macro call.
@@ -1354,6 +1381,93 @@ expand_arg([A|As], Ts, _L, Rest, Bs) ->
expand_arg([], Ts, L, Rest, Bs) ->
expand_macro(Ts, L, Rest, Bs).
+%%%
+%%% Here follows support for the ?FUNCTION_NAME and ?FUNCTION_ARITY
+%%% macros. Since the parser has not been run yet, we don't know the
+%%% name and arity of the current function. Therefore, we will need to
+%%% scan the beginning of the current form to extract the name and
+%%% arity of the function.
+%%%
+
+update_fun_name(Token, #epp{fname=Toks0}=St) when is_list(Toks0) ->
+ %% ?FUNCTION_NAME or ?FUNCTION_ARITY is used for the first time in
+ %% a function. First expand macros (except ?FUNCTION_NAME and
+ %% ?FUNCTION_ARITY) in the form.
+
+ Toks1 = (catch expand_macros(Toks0, St#epp{fname=undefined})),
+
+ %% Now extract the name and arity from the stream of tokens, and store
+ %% the result in the #epp{} record so we don't have to do it
+ %% again.
+
+ case Toks1 of
+ [{atom,_,Name},{'(',_}|Toks] ->
+ %% This is the beginning of a function definition.
+ %% Scan the token stream up to the matching right
+ %% parenthesis and count the number of arguments.
+ FA = update_fun_name_1(Toks, 1, {Name,0}, St),
+ St#epp{fname=FA};
+ [{'?',_}|_] ->
+ %% ?FUNCTION_NAME/?FUNCTION_ARITY used at the beginning
+ %% of a form. Does not make sense.
+ {var,_,Macro} = Token,
+ throw({error,loc(Token),{illegal_function_usage,Macro}});
+ _ when is_list(Toks1) ->
+ %% Not the beginning of a function (an attribute or a
+ %% syntax error).
+ {var,_,Macro} = Token,
+ throw({error,loc(Token),{illegal_function,Macro}});
+ _ ->
+ %% A macro expansion error. Return a dummy value and
+ %% let the caller notice and handle the error.
+ St#epp{fname={'_',0}}
+ end;
+update_fun_name(_Token, St) ->
+ St.
+
+update_fun_name_1([Tok|Toks], L, FA, St) ->
+ case classify_token(Tok) of
+ comma ->
+ if
+ L =:= 1 ->
+ {Name,Arity} = FA,
+ update_fun_name_1(Toks, L, {Name,Arity+1}, St);
+ true ->
+ update_fun_name_1(Toks, L, FA, St)
+ end;
+ left ->
+ update_fun_name_1(Toks, L+1, FA, St);
+ right when L =:= 1 ->
+ FA;
+ right ->
+ update_fun_name_1(Toks, L-1, FA, St);
+ other ->
+ case FA of
+ {Name,0} ->
+ update_fun_name_1(Toks, L, {Name,1}, St);
+ {_,_} ->
+ update_fun_name_1(Toks, L, FA, St)
+ end
+ end;
+update_fun_name_1([], _, FA, _) ->
+ %% Syntax error, but never mind.
+ FA.
+
+classify_token({C,_}) -> classify_token_1(C);
+classify_token(_) -> other.
+
+classify_token_1(',') -> comma;
+classify_token_1('(') -> left;
+classify_token_1('{') -> left;
+classify_token_1('[') -> left;
+classify_token_1('<<') -> left;
+classify_token_1(')') -> right;
+classify_token_1('}') -> right;
+classify_token_1(']') -> right;
+classify_token_1('>>') -> right;
+classify_token_1(_) -> other.
+
+
%%% stringify(Ts, L) returns a list of one token: a string which when
%%% tokenized would yield the token list Ts.
generated by cgit v1.2.3 (git 2.25.1) at 2025-01-14 08:16:09 +0000