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-rw-r--r--lib/stdlib/src/epp.erl132
1 files changed, 124 insertions, 8 deletions
diff --git a/lib/stdlib/src/epp.erl b/lib/stdlib/src/epp.erl
index b8e48bff6c..cc34d4bdd3 100644
--- a/lib/stdlib/src/epp.erl
+++ b/lib/stdlib/src/epp.erl
@@ -38,7 +38,7 @@
-type epp_handle() :: pid().
-type source_encoding() :: latin1 | utf8.
--type ifdef() :: 'ifdef' | 'ifndef' | 'else'.
+-type ifdef() :: 'ifdef' | 'ifndef' | 'if' | 'else'.
-type name() :: atom().
-type argspec() :: 'none' %No arguments
@@ -221,6 +221,8 @@ 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(elif_after_else) ->
+ "'elif' following 'else'";
format_error({'NYI',What}) ->
io_lib:format("not yet implemented '~s'", [What]);
format_error({error,Term}) ->
@@ -479,7 +481,7 @@ com_enc(_B, _Fun, _N, L, Ps) ->
com_enc_end([L | Ps]).
com_enc_end(Ps0) ->
- Ps = lists:reverse([lists:reverse(string:to_lower(P)) || P <- Ps0]),
+ Ps = lists:reverse([lists:reverse(lowercase(P)) || P <- Ps0]),
com_encoding(Ps).
com_encoding(["latin","1"|_]) ->
@@ -489,6 +491,9 @@ com_encoding(["utf","8"|_]) ->
com_encoding(_) ->
throw(no). % Don't try any further
+lowercase(S) ->
+ unicode:characters_to_list(string:lowercase(S)).
+
normalize_typed_record_fields([]) ->
{typed, []};
normalize_typed_record_fields(Fields) ->
@@ -568,6 +573,7 @@ init_server(Pid, Name, Options, St0) ->
predef_macros(File) ->
Machine = list_to_atom(erlang:system_info(machine)),
Anno = line1(),
+ OtpVersion = list_to_integer(erlang:system_info(otp_release)),
Defs = [{'FILE', {none,[{string,Anno,File}]}},
{'FUNCTION_NAME', undefined},
{'FUNCTION_ARITY', undefined},
@@ -577,7 +583,8 @@ predef_macros(File) ->
{'BASE_MODULE', undefined},
{'BASE_MODULE_STRING', undefined},
{'MACHINE', {none,[{atom,Anno,Machine}]}},
- {Machine, {none,[{atom,Anno,true}]}}
+ {Machine, {none,[{atom,Anno,true}]}},
+ {'OTP_RELEASE', {none,[{integer,Anno,OtpVersion}]}}
],
maps:from_list(Defs).
@@ -1082,21 +1089,118 @@ scan_else(_Toks, Else, From, St) ->
epp_reply(From, {error,{loc(Else),epp,{bad,'else'}}}),
wait_req_scan(St).
-%% scan_if(Tokens, EndifToken, From, EppState)
+%% scan_if(Tokens, IfToken, From, EppState)
%% Handle the conditional parsing of a file.
-%% Report a badly formed if test and then treat as false macro.
+scan_if([{'(',_}|_]=Toks, If, From, St) ->
+ try eval_if(Toks, St) of
+ true ->
+ scan_toks(From, St#epp{istk=['if'|St#epp.istk]});
+ _ ->
+ skip_toks(From, St, ['if'])
+ catch
+ throw:Error0 ->
+ Error = case Error0 of
+ {_,erl_parse,_} ->
+ {error,Error0};
+ _ ->
+ {error,{loc(If),epp,Error0}}
+ end,
+ epp_reply(From, Error),
+ wait_req_skip(St, ['if'])
+ end;
scan_if(_Toks, If, From, St) ->
- epp_reply(From, {error,{loc(If),epp,{'NYI','if'}}}),
+ epp_reply(From, {error,{loc(If),epp,{bad,'if'}}}),
wait_req_skip(St, ['if']).
+eval_if(Toks0, St) ->
+ Toks = expand_macros(Toks0, St),
+ Es1 = case erl_parse:parse_exprs(Toks) of
+ {ok,Es0} -> Es0;
+ {error,E} -> throw(E)
+ end,
+ Es = rewrite_expr(Es1, St),
+ assert_guard_expr(Es),
+ Bs = erl_eval:new_bindings(),
+ LocalFun = fun(_Name, _Args) ->
+ error(badarg)
+ end,
+ try erl_eval:exprs(Es, Bs, {value,LocalFun}) of
+ {value,Res,_} ->
+ Res
+ catch
+ _:_ ->
+ false
+ end.
+
+assert_guard_expr([E0]) ->
+ E = rewrite_expr(E0, none),
+ case erl_lint:is_guard_expr(E) of
+ false ->
+ throw({bad,'if'});
+ true ->
+ ok
+ end;
+assert_guard_expr(_) ->
+ throw({bad,'if'}).
+
+%% Dual-purpose rewriting function. When the second argument is
+%% an #epp{} record, calls to defined(Symbol) will be evaluated.
+%% When the second argument is 'none', legal calls to our built-in
+%% functions are eliminated in order to turn the expression into
+%% a legal guard expression.
+
+rewrite_expr({call,_,{atom,_,defined},[N0]}, #epp{macs=Macs}) ->
+ %% Evaluate defined(Symbol).
+ N = case N0 of
+ {var,_,N1} -> N1;
+ {atom,_,N1} -> N1;
+ _ -> throw({bad,'if'})
+ end,
+ {atom,0,maps:is_key(N, Macs)};
+rewrite_expr({call,_,{atom,_,Name},As0}, none) ->
+ As = rewrite_expr(As0, none),
+ Arity = length(As),
+ case erl_internal:bif(Name, Arity) andalso
+ not erl_internal:guard_bif(Name, Arity) of
+ false ->
+ %% A guard BIF, an -if built-in, or an unknown function.
+ %% Eliminate the call so that erl_lint will not complain.
+ %% The call might fail later at evaluation time.
+ to_conses(As);
+ true ->
+ %% An auto-imported BIF (not guard BIF). Not allowed.
+ throw({bad,'if'})
+ end;
+rewrite_expr([H|T], St) ->
+ [rewrite_expr(H, St)|rewrite_expr(T, St)];
+rewrite_expr(Tuple, St) when is_tuple(Tuple) ->
+ list_to_tuple(rewrite_expr(tuple_to_list(Tuple), St));
+rewrite_expr(Other, _) ->
+ Other.
+
+to_conses([H|T]) ->
+ {cons,0,H,to_conses(T)};
+to_conses([]) ->
+ {nil,0}.
+
%% scan_elif(Tokens, EndifToken, From, EppState)
%% Handle the conditional parsing of a file.
%% Report a badly formed if test and then treat as false macro.
scan_elif(_Toks, Elif, From, St) ->
- epp_reply(From, {error,{loc(Elif),epp,{'NYI','elif'}}}),
- wait_req_scan(St).
+ case St#epp.istk of
+ ['else'|Cis] ->
+ epp_reply(From, {error,{loc(Elif),
+ epp,{illegal,"unbalanced",'elif'}}}),
+ wait_req_skip(St#epp{istk=Cis}, ['else']);
+ [_I|Cis] ->
+ skip_toks(From, St#epp{istk=Cis}, ['elif']);
+ [] ->
+ epp_reply(From, {error,{loc(Elif),epp,
+ {illegal,"unbalanced",elif}}}),
+ wait_req_scan(St)
+ end.
%% scan_endif(Tokens, EndifToken, From, EppState)
%% If we are in an if body then exit it, else report an error.
@@ -1155,6 +1259,8 @@ skip_toks(From, St, [I|Sis]) ->
skip_toks(From, St#epp{location=Cl}, ['if',I|Sis]);
{ok,[{'-',_Lh},{atom,_Le,'else'}=Else|_Toks],Cl}->
skip_else(Else, From, St#epp{location=Cl}, [I|Sis]);
+ {ok,[{'-',_Lh},{atom,_Le,'elif'}=Elif|Toks],Cl}->
+ skip_elif(Toks, Elif, From, St#epp{location=Cl}, [I|Sis]);
{ok,[{'-',_Lh},{atom,_Le,endif}|_Toks],Cl} ->
skip_toks(From, St#epp{location=Cl}, Sis);
{ok,_Toks,Cl} ->
@@ -1185,11 +1291,21 @@ skip_toks(From, St, []) ->
skip_else(Else, From, St, ['else'|Sis]) ->
epp_reply(From, {error,{loc(Else),epp,{illegal,"repeated",'else'}}}),
wait_req_skip(St, ['else'|Sis]);
+skip_else(_Else, From, St, ['elif'|Sis]) ->
+ skip_toks(From, St, ['else'|Sis]);
skip_else(_Else, From, St, [_I]) ->
scan_toks(From, St#epp{istk=['else'|St#epp.istk]});
skip_else(_Else, From, St, Sis) ->
skip_toks(From, St, Sis).
+skip_elif(_Toks, Elif, From, St, ['else'|_]=Sis) ->
+ epp_reply(From, {error,{loc(Elif),epp,elif_after_else}}),
+ wait_req_skip(St, Sis);
+skip_elif(Toks, Elif, From, St, [_I]) ->
+ scan_if(Toks, Elif, From, St);
+skip_elif(_Toks, _Elif, From, St, Sis) ->
+ skip_toks(From, St, Sis).
+
%% macro_pars(Tokens, ArgStack)
%% macro_expansion(Tokens, Anno)
%% Extract the macro parameters and the expansion from a macro definition.
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-18 03:29:10 +0000