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authorBjörn Gustavsson <[email protected]>2016-02-18 15:55:44 +0100
committerBjörn Gustavsson <[email protected]>2016-02-18 15:55:44 +0100
commit517a4b9fb9bc62f6d172d13113526835f37cc396 (patch)
tree359ceaa8ff421de4dc2896e659b1f5161efb67ab
parent24f0d567ceffb0f1555bc3032b7801ba377e5a3b (diff)
parent1604b874828e8ef992c8e17e06e7af20a0f1574b (diff)
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Merge branch 'bjorn/stdlib/function-macro/OTP-13059'
* bjorn/stdlib/function-macro/OTP-13059: Implement ?FUNCTION_NAME and ?FUNCTION_ARITY macros epp: Refactor expand_macros()
-rw-r--r--lib/stdlib/src/epp.erl152
-rw-r--r--lib/stdlib/test/epp_SUITE.erl91
-rw-r--r--system/doc/reference_manual/macros.xml4
3 files changed, 224 insertions, 23 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.
diff --git a/lib/stdlib/test/epp_SUITE.erl b/lib/stdlib/test/epp_SUITE.erl
index da5a079303..0c00e104b7 100644
--- a/lib/stdlib/test/epp_SUITE.erl
+++ b/lib/stdlib/test/epp_SUITE.erl
@@ -27,7 +27,7 @@
pmod/1, not_circular/1, skip_header/1, otp_6277/1, otp_7702/1,
otp_8130/1, overload_mac/1, otp_8388/1, otp_8470/1,
otp_8562/1, otp_8665/1, otp_8911/1, otp_10302/1, otp_10820/1,
- otp_11728/1, encoding/1, extends/1]).
+ otp_11728/1, encoding/1, extends/1, function_macro/1]).
-export([epp_parse_erl_form/2]).
@@ -70,7 +70,7 @@ all() ->
not_circular, skip_header, otp_6277, otp_7702, otp_8130,
overload_mac, otp_8388, otp_8470, otp_8562,
otp_8665, otp_8911, otp_10302, otp_10820, otp_11728,
- encoding, extends].
+ encoding, extends, function_macro].
groups() ->
[{upcase_mac, [], [upcase_mac_1, upcase_mac_2]},
@@ -843,8 +843,9 @@ otp_8130(Config) when is_list(Config) ->
"t() -> ?a.\n"),
?line {ok,Epp} = epp:open(File, []),
PreDefMacs = macs(Epp),
- ['BASE_MODULE','BASE_MODULE_STRING','BEAM','FILE','LINE',
- 'MACHINE','MODULE','MODULE_STRING'] = PreDefMacs,
+ ['BASE_MODULE','BASE_MODULE_STRING','BEAM','FILE',
+ 'FUNCTION_ARITY','FUNCTION_NAME',
+ 'LINE','MACHINE','MODULE','MODULE_STRING'] = PreDefMacs,
?line {ok,[{'-',_},{atom,_,file}|_]} = epp:scan_erl_form(Epp),
?line {ok,[{'-',_},{atom,_,module}|_]} = epp:scan_erl_form(Epp),
?line {ok,[{atom,_,t}|_]} = epp:scan_erl_form(Epp),
@@ -1491,6 +1492,88 @@ extends(Config) ->
[] = run(Config, Ts),
ok.
+function_macro(Config) ->
+ Cs = [{f_c1,
+ <<"-define(FUNCTION_NAME, a).\n"
+ "-define(FUNCTION_ARITY, a).\n"
+ "-define(FS,\n"
+ " atom_to_list(?FUNCTION_NAME) ++ \"/\" ++\n"
+ " integer_to_list(?FUNCTION_ARITY)).\n"
+ "-attr({f,?FUNCTION_NAME}).\n"
+ "-attr2(?FS).\n"
+ "-file(?FUNCTION_ARITY, 1).\n"
+ "f1() ?FUNCTION_NAME/?FUNCTION_ARITY.\n"
+ "f2(?FUNCTION_NAME.\n">>,
+ {errors,[{1,epp,{redefine_predef,'FUNCTION_NAME'}},
+ {2,epp,{redefine_predef,'FUNCTION_ARITY'}},
+ {6,epp,{illegal_function,'FUNCTION_NAME'}},
+ {7,epp,{illegal_function,'FUNCTION_NAME'}},
+ {8,epp,{illegal_function,'FUNCTION_ARITY'}},
+ {9,erl_parse,["syntax error before: ","f1"]},
+ {10,erl_parse,["syntax error before: ","'.'"]}],
+ []}},
+
+ {f_c2,
+ <<"a({a) -> ?FUNCTION_NAME.\n"
+ "b(}{) -> ?FUNCTION_ARITY.\n"
+ "c(?FUNCTION_NAME, ?not_defined) -> ok.\n">>,
+ {errors,[{1,erl_parse,["syntax error before: ","')'"]},
+ {2,erl_parse,["syntax error before: ","'}'"]},
+ {3,epp,{undefined,not_defined,none}}],
+ []}},
+
+ {f_c3,
+ <<"?FUNCTION_NAME() -> ok.\n"
+ "?FUNCTION_ARITY() -> ok.\n">>,
+ {errors,[{1,epp,{illegal_function_usage,'FUNCTION_NAME'}},
+ {2,epp,{illegal_function_usage,'FUNCTION_ARITY'}}],
+ []}}
+ ],
+
+ [] = compile(Config, Cs),
+
+ Ts = [{f_1,
+ <<"t() -> {a,0} = a(), {b,1} = b(1), {c,2} = c(1, 2),\n"
+ " {d,1} = d({d,1}), {foo,1} = foo(foo), ok.\n"
+ "a() -> {?FUNCTION_NAME,?FUNCTION_ARITY}.\n"
+ "b(_) -> {?FUNCTION_NAME,?FUNCTION_ARITY}.\n"
+ "c(_, (_)) -> {?FUNCTION_NAME,?FUNCTION_ARITY}.\n"
+ "d({?FUNCTION_NAME,?FUNCTION_ARITY}=F) -> F.\n"
+ "-define(FOO, foo).\n"
+ "?FOO(?FOO) -> {?FUNCTION_NAME,?FUNCTION_ARITY}.\n">>,
+ ok},
+
+ {f_2,
+ <<"t() ->\n"
+ " A = {a,[<<0:24>>,#{a=>1,b=>2}]},\n"
+ " 1 = a(A),\n"
+ " ok.\n"
+ "a({a,[<<_,_,_>>,#{a:=1,b:=2}]}) -> ?FUNCTION_ARITY.\n">>,
+ ok},
+
+ {f_3,
+ <<"-define(FS,\n"
+ " atom_to_list(?FUNCTION_NAME) ++ \"/\" ++\n"
+ " integer_to_list(?FUNCTION_ARITY)).\n"
+ "t() ->\n"
+ " {t,0} = {?FUNCTION_NAME,?FUNCTION_ARITY},\n"
+ " \"t/0\" = ?FS,\n"
+ " ok.\n">>,
+ ok},
+
+ {f_4,
+ <<"-define(__, _, _).\n"
+ "-define(FF, ?FUNCTION_NAME, ?FUNCTION_ARITY).\n"
+ "a(?__) -> 2 = ?FUNCTION_ARITY.\n"
+ "b(?FUNCTION_ARITY, ?__) -> ok.\n"
+ "c(?FF) -> ok.\n"
+ "t() -> a(1, 2), b(3, 1, 2), c(c, 2), ok.\n">>,
+ ok}
+ ],
+ [] = run(Config, Ts),
+
+ ok.
+
check(Config, Tests) ->
eval_tests(Config, fun check_test/2, Tests).
diff --git a/system/doc/reference_manual/macros.xml b/system/doc/reference_manual/macros.xml
index 3b1f72e5d6..42ea639b54 100644
--- a/system/doc/reference_manual/macros.xml
+++ b/system/doc/reference_manual/macros.xml
@@ -146,6 +146,10 @@ bar(X) ->
<item>The current line number.</item>
<tag><c>?MACHINE</c>.</tag>
<item>The machine name, <c>'BEAM'</c>.</item>
+ <tag><c>?FUNCTION_NAME</c></tag>
+ <item>The name of the current function.</item>
+ <tag><c>?FUNCTION_ARITY</c></tag>
+ <item>The arity (number of arguments) for the current function.</item>
</taglist>
</section>