diff options
Diffstat (limited to 'lib/stdlib/src/epp.erl')
| -rw-r--r-- | lib/stdlib/src/epp.erl | 118 |
1 files changed, 116 insertions, 2 deletions
diff --git a/lib/stdlib/src/epp.erl b/lib/stdlib/src/epp.erl index f55aff1e00..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}, @@ -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) 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)}); @@ -1214,6 +1225,22 @@ get_macro_uses({M,Arity}, U) -> expand_macros([{'?',_Lq},{atom,_Lm,M}=MacT|Toks], St) -> expand_macros(MacT, M, Toks, St); %% Special macros +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, St)]; @@ -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. |