%% -*- erlang-indent-level: 4 -*-
%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1996-2010. All Rights Reserved.
%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
%%
%% %CopyrightEnd%
%%
%% Do necessary checking of Erlang code.
%% N.B. All the code necessary for checking structs (tagged tuples) is
%% here. Just comment out the lines in pattern/2, gexpr/3 and expr/3.
-module(erl_lint).
-export([module/1,module/2,module/3,format_error/1]).
-export([exprs/2,exprs_opt/3,used_vars/2]). % Used from erl_eval.erl.
-export([is_pattern_expr/1,is_guard_test/1,is_guard_test/2]).
-export([is_guard_expr/1]).
-export([bool_option/4,value_option/3,value_option/7]).
-export([modify_line/2]).
-import(lists, [member/2,map/2,foldl/3,foldr/3,mapfoldl/3,all/2,reverse/1]).
%% bool_option(OnOpt, OffOpt, Default, Options) -> boolean().
%% value_option(Flag, Default, Options) -> Value.
%% value_option(Flag, Default, OnOpt, OnVal, OffOpt, OffVal, Options) ->
%% Value.
%% The option handling functions.
-spec bool_option(atom(), atom(), boolean(), [compile:option()]) -> boolean().
bool_option(On, Off, Default, Opts) ->
foldl(fun (Opt, _Def) when Opt =:= On -> true;
(Opt, _Def) when Opt =:= Off -> false;
(_Opt, Def) -> Def
end, Default, Opts).
value_option(Flag, Default, Opts) ->
foldl(fun ({Opt,Val}, _Def) when Opt =:= Flag -> Val;
(_Opt, Def) -> Def
end, Default, Opts).
value_option(Flag, Default, On, OnVal, Off, OffVal, Opts) ->
foldl(fun ({Opt,Val}, _Def) when Opt =:= Flag -> Val;
(Opt, _Def) when Opt =:= On -> OnVal;
(Opt, _Def) when Opt =:= Off -> OffVal;
(_Opt, Def) -> Def
end, Default, Opts).
%% The error and warning info structures, {Line,Module,Descriptor},
%% are kept in their seperate fields in the lint state record together
%% with the name of the file (when a new file is entered, marked by
%% the 'file' attribute, then the field 'file' of the lint record is
%% set). At the end of the run these lists are packed into a list of
%% {FileName,ErrorDescList} pairs which are returned.
-include_lib("stdlib/include/erl_bits.hrl").
%%-define(DEBUGF(X,Y), io:format(X, Y)).
-define(DEBUGF(X,Y), void).
-type line() :: erl_scan:line(). % a convenient alias
-type fa() :: {atom(), arity()}. % function+arity
-type ta() :: {atom(), arity()}. % type+arity
%% Usage of records, functions, and imports. The variable table, which
%% is passed on as an argument, holds the usage of variables.
-record(usage, {
calls = dict:new(), %Who calls who
imported = [], %Actually imported functions
used_records=sets:new() :: set(), %Used record definitions
used_types = dict:new() :: dict() %Used type definitions
}).
%% Define the lint state record.
%% 'called' and 'exports' contain {Line, {Function, Arity}},
%% the other function collections contain {Function, Arity}.
-record(lint, {state=start :: 'start' | 'attribute' | 'function',
module=[], %Module
package="", %Module package
extends=[], %Extends
behaviour=[], %Behaviour
exports=gb_sets:empty() :: gb_set(), %Exports
imports=[], %Imports
mod_imports=dict:new() :: dict(), %Module Imports
compile=[], %Compile flags
records=dict:new() :: dict(), %Record definitions
locals=gb_sets:empty() :: gb_set(), %All defined functions (prescanned)
no_auto=gb_sets:empty() :: gb_set(), %Functions explicitly not autoimported
defined=gb_sets:empty() :: gb_set(), %Defined fuctions
on_load=[] :: [fa()], %On-load function
on_load_line=0 :: line(), %Line for on_load
clashes=[], %Exported functions named as BIFs
not_deprecated=[], %Not considered deprecated
func=[], %Current function
warn_format=0, %Warn format calls
enabled_warnings=[], %All enabled warnings (ordset).
errors=[], %Current errors
warnings=[], %Current warnings
global_vt=[], %The global VarTable
file = "" :: string(), %From last file attribute
recdef_top=false :: boolean(), %true in record initialisation
%outside any fun or lc
xqlc= false :: boolean(), %true if qlc.hrl included
new = false :: boolean(), %Has user-defined 'new/N'
called= [] :: [{fa(),line()}], %Called functions
usage = #usage{} :: #usage{},
specs = dict:new() :: dict(), %Type specifications
types = dict:new() :: dict(), %Type definitions
exp_types=gb_sets:empty():: gb_set() %Exported types
}).
-type lint_state() :: #lint{}.
%% format_error(Error)
%% Return a string describing the error.
format_error(undefined_module) ->
"no module definition";
format_error({bad_module_name, M}) ->
io_lib:format("bad module name '~s'", [M]);
format_error(redefine_module) ->
"redefining module";
format_error(redefine_extends) ->
"redefining extends attribute";
format_error(extends_self) ->
"cannot extend from self";
%% format_error({redefine_mod_import, M, P}) ->
%% io_lib:format("module '~s' already imported from package '~s'", [M, P]);
format_error(invalid_call) ->
"invalid function call";
format_error(invalid_record) ->
"invalid record expression";
format_error({attribute,A}) ->
io_lib:format("attribute '~w' after function definitions", [A]);
format_error({missing_qlc_hrl,A}) ->
io_lib:format("qlc:q/~w called, but \"qlc.hrl\" not included", [A]);
format_error({redefine_import,{bif,{F,A},M}}) ->
io_lib:format("function ~w/~w already auto-imported from ~w", [F,A,M]);
format_error({redefine_import,{{F,A},M}}) ->
io_lib:format("function ~w/~w already imported from ~w", [F,A,M]);
format_error({bad_inline,{F,A}}) ->
io_lib:format("inlined function ~w/~w undefined", [F,A]);
format_error({invalid_deprecated,D}) ->
io_lib:format("badly formed deprecated attribute ~w", [D]);
format_error(invalid_extends) ->
"badly formed extends attribute";
format_error(define_instance) ->
"defining instance function not allowed in abstract module";
format_error({bad_deprecated,{F,A}}) ->
io_lib:format("deprecated function ~w/~w undefined or not exported", [F,A]);
format_error({bad_nowarn_unused_function,{F,A}}) ->
io_lib:format("function ~w/~w undefined", [F,A]);
format_error({bad_nowarn_bif_clash,{F,A}}) ->
io_lib:format("function ~w/~w undefined", [F,A]);
format_error(disallowed_nowarn_bif_clash) ->
io_lib:format("compile directive nowarn_bif_clash is no longer allowed,~n"
" - use explicit module names or -compile({no_auto_import, [F/A]})", []);
format_error({bad_nowarn_deprecated_function,{M,F,A}}) ->
io_lib:format("~w:~w/~w is not a deprecated function", [M,F,A]);
format_error({bad_on_load,Term}) ->
io_lib:format("badly formed on_load attribute: ~w", [Term]);
format_error(multiple_on_loads) ->
"more than one on_load attribute";
format_error({bad_on_load_arity,{F,A}}) ->
io_lib:format("function ~w/~w has wrong arity (must be 0)", [F,A]);
format_error({undefined_on_load,{F,A}}) ->
io_lib:format("function ~w/~w undefined", [F,A]);
format_error(export_all) ->
"export_all flag enabled - all functions will be exported";
format_error({duplicated_export, {F,A}}) ->
io_lib:format("function ~w/~w already exported", [F,A]);
format_error({unused_import,{{F,A},M}}) ->
io_lib:format("import ~w:~w/~w is unused", [M,F,A]);
format_error({undefined_function,{F,A}}) ->
io_lib:format("function ~w/~w undefined", [F,A]);
format_error({redefine_function,{F,A}}) ->
io_lib:format("function ~w/~w already defined", [F,A]);
format_error({define_import,{F,A}}) ->
io_lib:format("defining imported function ~w/~w", [F,A]);
format_error({unused_function,{F,A}}) ->
io_lib:format("function ~w/~w is unused", [F,A]);
format_error({call_to_redefined_bif,{F,A}}) ->
io_lib:format("ambiguous call of redefined auto-imported BIF ~w/~w~n"
" - use erlang:~w/~w or \"-compile({no_auto_import,[~w/~w]}).\" "
"to resolve name clash", [F,A,F,A,F,A]);
format_error({call_to_redefined_old_bif,{F,A}}) ->
io_lib:format("ambiguous call of redefined pre R14 auto-imported BIF ~w/~w~n"
" - use erlang:~w/~w or \"-compile({no_auto_import,[~w/~w]}).\" "
"to resolve name clash", [F,A,F,A,F,A]);
format_error({redefine_old_bif_import,{F,A}}) ->
io_lib:format("import directive redefines pre R14 auto-imported BIF ~w/~w~n"
" - use \"-compile({no_auto_import,[~w/~w]}).\" "
"to resolve name clash", [F,A,F,A]);
format_error({redefine_bif_import,{F,A}}) ->
io_lib:format("import directive redefines auto-imported BIF ~w/~w~n"
" - use \"-compile({no_auto_import,[~w/~w]}).\" to resolve name clash", [F,A,F,A]);
format_error({deprecated, MFA, ReplacementMFA, Rel}) ->
io_lib:format("~s is deprecated and will be removed in ~s; use ~s",
[format_mfa(MFA), Rel, format_mfa(ReplacementMFA)]);
format_error({deprecated, {M1, F1, A1}, String}) when is_list(String) ->
io_lib:format("~p:~p/~p: ~s", [M1, F1, A1, String]);
format_error({removed, MFA, ReplacementMFA, Rel}) ->
io_lib:format("call to ~s will fail, since it was removed in ~s; "
"use ~s", [format_mfa(MFA), Rel, format_mfa(ReplacementMFA)]);
format_error({removed, MFA, String}) when is_list(String) ->
io_lib:format("~s: ~s", [format_mfa(MFA), String]);
format_error({obsolete_guard, {F, A}}) ->
io_lib:format("~p/~p obsolete", [F, A]);
format_error({reserved_for_future,K}) ->
io_lib:format("atom ~w: future reserved keyword - rename or quote", [K]);
%% --- patterns and guards ---
format_error(illegal_pattern) -> "illegal pattern";
format_error(illegal_bin_pattern) ->
"binary patterns cannot be matched in parallel using '='";
format_error(illegal_expr) -> "illegal expression";
format_error(illegal_guard_expr) -> "illegal guard expression";
%% --- exports ---
format_error({explicit_export,F,A}) ->
io_lib:format("in this release, the call to ~w/~w must be written "
"like this: erlang:~w/~w",
[F,A,F,A]);
%% --- records ---
format_error({undefined_record,T}) ->
io_lib:format("record ~w undefined", [T]);
format_error({redefine_record,T}) ->
io_lib:format("record ~w already defined", [T]);
format_error({redefine_field,T,F}) ->
io_lib:format("field ~w already defined in record ~w", [F,T]);
format_error({undefined_field,T,F}) ->
io_lib:format("field ~w undefined in record ~w", [F,T]);
format_error(illegal_record_info) ->
"illegal record info";
format_error({field_name_is_variable,T,F}) ->
io_lib:format("field ~w is not an atom or _ in record ~w", [F,T]);
format_error({wildcard_in_update,T}) ->
io_lib:format("meaningless use of _ in update of record ~w", [T]);
format_error({unused_record,T}) ->
io_lib:format("record ~w is unused", [T]);
format_error({untyped_record,T}) ->
io_lib:format("record ~w has field(s) without type information", [T]);
%% --- variables ----
format_error({unbound_var,V}) ->
io_lib:format("variable ~w is unbound", [V]);
format_error({unsafe_var,V,{What,Where}}) ->
io_lib:format("variable ~w unsafe in ~w ~s",
[V,What,format_where(Where)]);
format_error({exported_var,V,{What,Where}}) ->
io_lib:format("variable ~w exported from ~w ~s",
[V,What,format_where(Where)]);
format_error({shadowed_var,V,In}) ->
io_lib:format("variable ~w shadowed in ~w", [V,In]);
format_error({unused_var, V}) ->
io_lib:format("variable ~w is unused", [V]);
format_error({variable_in_record_def,V}) ->
io_lib:format("variable ~w in record definition", [V]);
%% --- binaries ---
format_error({undefined_bittype,Type}) ->
io_lib:format("bit type ~w undefined", [Type]);
format_error({bittype_mismatch,T1,T2,What}) ->
io_lib:format("bit type mismatch (~s) between ~p and ~p", [What,T1,T2]);
format_error(bittype_unit) ->
"a bit unit size must not be specified unless a size is specified too";
format_error(illegal_bitsize) ->
"illegal bit size";
format_error(unsized_binary_not_at_end) ->
"a binary field without size is only allowed at the end of a binary pattern";
format_error(typed_literal_string) ->
"a literal string in a binary pattern must not have a type or a size";
format_error(utf_bittype_size_or_unit) ->
"neither size nor unit must be given for segments of type utf8/utf16/utf32";
format_error({bad_bitsize,Type}) ->
io_lib:format("bad ~s bit size", [Type]);
%% --- behaviours ---
format_error({conflicting_behaviours,{Name,Arity},B,FirstL,FirstB}) ->
io_lib:format("conflicting behaviours - callback ~w/~w required by both '~p' "
"and '~p' ~s", [Name,Arity,B,FirstB,format_where(FirstL)]);
format_error({undefined_behaviour_func, {Func,Arity}, Behaviour}) ->
io_lib:format("undefined callback function ~w/~w (behaviour '~w')",
[Func,Arity,Behaviour]);
format_error({undefined_behaviour_func, {Func,Arity,_Spec}, Behaviour}) ->
format_error({undefined_behaviour_func, {Func,Arity}, Behaviour});
format_error({undefined_behaviour,Behaviour}) ->
io_lib:format("behaviour ~w undefined", [Behaviour]);
format_error({undefined_behaviour_callbacks,Behaviour}) ->
io_lib:format("behaviour ~w callback functions are undefined",
[Behaviour]);
format_error({ill_defined_behaviour_callbacks,Behaviour}) ->
io_lib:format("behaviour ~w callback functions erroneously defined",
[Behaviour]);
%% --- types and specs ---
format_error({singleton_typevar, Name}) ->
io_lib:format("type variable ~w is only used once (is unbound)", [Name]);
format_error({duplicated_export_type, {T, A}}) ->
io_lib:format("type ~w/~w already exported", [T, A]);
format_error({undefined_type, {TypeName, Arity}}) ->
io_lib:format("type ~w~s undefined", [TypeName, gen_type_paren(Arity)]);
format_error({unused_type, {TypeName, Arity}}) ->
io_lib:format("type ~w~s is unused", [TypeName, gen_type_paren(Arity)]);
format_error({new_builtin_type, {TypeName, Arity}}) ->
io_lib:format("type ~w~s is a new builtin type; "
"its (re)definition is allowed only until the next release",
[TypeName, gen_type_paren(Arity)]);
format_error({builtin_type, {TypeName, Arity}}) ->
io_lib:format("type ~w~s is a builtin type; it cannot be redefined",
[TypeName, gen_type_paren(Arity)]);
format_error({renamed_type, OldName, NewName}) ->
io_lib:format("type ~w() is now called ~w(); "
"please use the new name instead", [OldName, NewName]);
format_error({redefine_type, {TypeName, Arity}}) ->
io_lib:format("type ~w~s already defined",
[TypeName, gen_type_paren(Arity)]);
format_error({type_syntax, Constr}) ->
io_lib:format("bad ~w type", [Constr]);
format_error({redefine_spec, {M, F, A}}) ->
io_lib:format("spec for ~w:~w/~w already defined", [M, F, A]);
format_error({spec_fun_undefined, {M, F, A}}) ->
io_lib:format("spec for undefined function ~w:~w/~w", [M, F, A]);
format_error({missing_spec, {F,A}}) ->
io_lib:format("missing specification for function ~w/~w", [F, A]);
format_error(spec_wrong_arity) ->
"spec has the wrong arity";
format_error({imported_predefined_type, Name}) ->
io_lib:format("referring to built-in type ~w as a remote type; "
"please take out the module name", [Name]);
%% --- obsolete? unused? ---
format_error({format_error, {Fmt, Args}}) ->
io_lib:format(Fmt, Args);
format_error({mnemosyne, What}) ->
"mnemosyne " ++ What ++ ", missing transformation".
gen_type_paren(Arity) when is_integer(Arity), Arity >= 0 ->
gen_type_paren_1(Arity, ")").
gen_type_paren_1(0, Acc) -> "(" ++ Acc;
gen_type_paren_1(1, Acc) -> "(_" ++ Acc;
gen_type_paren_1(N, Acc) -> gen_type_paren_1(N - 1, ",_" ++ Acc).
format_mfa({M, F, [_|_]=As}) ->
","++ArityString = lists:append([[$,|integer_to_list(A)] || A <- As]),
format_mf(M, F, ArityString);
format_mfa({M, F, A}) when is_integer(A) ->
format_mf(M, F, integer_to_list(A)).
format_mf(M, F, ArityString) when is_atom(M), is_atom(F) ->
atom_to_list(M) ++ ":" ++ atom_to_list(F) ++ "/" ++ ArityString.
format_where(L) when is_integer(L) ->
io_lib:format("(line ~p)", [L]);
format_where({L,C}) when is_integer(L), is_integer(C) ->
io_lib:format("(line ~p, column ~p)", [L, C]).
%% Local functions that are somehow automatically generated.
pseudolocals() ->
[{module_info,0}, {module_info,1}, {record_info,2}].
%%
%% Used by erl_eval.erl to check commands.
%%
exprs(Exprs, BindingsList) ->
exprs_opt(Exprs, BindingsList, []).
exprs_opt(Exprs, BindingsList, Opts) ->
{St0,Vs} = foldl(fun({{record,_SequenceNumber,_Name},Attr0}, {St1,Vs1}) ->
Attr = zip_file_and_line(Attr0, "none"),
{attribute_state(Attr, St1),Vs1};
({V,_}, {St1,Vs1}) ->
{St1,[{V,{bound,unused,[]}} | Vs1]}
end, {start("nofile",Opts),[]}, BindingsList),
Vt = orddict:from_list(Vs),
{_Evt,St} = exprs(zip_file_and_line(Exprs, "nofile"), Vt, St0),
return_status(St).
used_vars(Exprs, BindingsList) ->
Vs = foldl(fun({{record,_SequenceNumber,_Name},_Attr}, Vs0) -> Vs0;
({V,_Val}, Vs0) -> [{V,{bound,unused,[]}} | Vs0]
end, [], BindingsList),
Vt = orddict:from_list(Vs),
{Evt,_St} = exprs(zip_file_and_line(Exprs, "nofile"), Vt, start()),
{ok, foldl(fun({V,{_,used,_}}, L) -> [V | L];
(_, L) -> L
end, [], Evt)}.
%% module([Form]) ->
%% module([Form], FileName) ->
%% module([Form], FileName, [CompileOption]) ->
%% {ok,[Warning]} | {error,[Error],[Warning]}
%% Start processing a module. Define predefined functions and exports and
%% apply_lambda/2 has been called to shut lint up. N.B. these lists are
%% really all ordsets!
module(Forms) ->
Opts = compiler_options(Forms),
St = forms(Forms, start("nofile", Opts)),
return_status(St).
module(Forms, FileName) ->
Opts = compiler_options(Forms),
St = forms(Forms, start(FileName, Opts)),
return_status(St).
module(Forms, FileName, Opts0) ->
%% We want the options given on the command line to take
%% precedence over options in the module.
Opts = compiler_options(Forms) ++ Opts0,
St = forms(Forms, start(FileName, Opts)),
return_status(St).
compiler_options(Forms) ->
lists:flatten([C || {attribute,_,compile,C} <- Forms]).
%% start() -> State
%% start(FileName, [Option]) -> State
start() ->
start("nofile", []).
start(File, Opts) ->
Enabled0 =
[{unused_vars,
bool_option(warn_unused_vars, nowarn_unused_vars,
true, Opts)},
{export_all,
bool_option(warn_export_all, nowarn_export_all,
false, Opts)},
{export_vars,
bool_option(warn_export_vars, nowarn_export_vars,
false, Opts)},
{shadow_vars,
bool_option(warn_shadow_vars, nowarn_shadow_vars,
true, Opts)},
{unused_import,
bool_option(warn_unused_import, nowarn_unused_import,
false, Opts)},
{unused_function,
bool_option(warn_unused_function, nowarn_unused_function,
true, Opts)},
{bif_clash,
bool_option(warn_bif_clash, nowarn_bif_clash,
true, Opts)},
{unused_record,
bool_option(warn_unused_record, nowarn_unused_record,
true, Opts)},
{deprecated_function,
bool_option(warn_deprecated_function, nowarn_deprecated_function,
true, Opts)},
{obsolete_guard,
bool_option(warn_obsolete_guard, nowarn_obsolete_guard,
true, Opts)},
{untyped_record,
bool_option(warn_untyped_record, nowarn_untyped_record,
false, Opts)},
{missing_spec,
bool_option(warn_missing_spec, nowarn_missing_spec,
false, Opts)},
{missing_spec_all,
bool_option(warn_missing_spec_all, nowarn_missing_spec_all,
false, Opts)}
],
Enabled1 = [Category || {Category,true} <- Enabled0],
Enabled = ordsets:from_list(Enabled1),
Calls = case ordsets:is_element(unused_function, Enabled) of
true ->
dict:from_list([{{module_info,1},pseudolocals()}]);
false ->
undefined
end,
#lint{state = start,
exports = gb_sets:from_list([{module_info,0},{module_info,1}]),
mod_imports = dict:from_list([{erlang,erlang}]),
compile = Opts,
%% Internal pseudo-functions must appear as defined/reached.
defined = gb_sets:from_list(pseudolocals()),
called = [{F,0} || F <- pseudolocals()],
usage = #usage{calls=Calls},
warn_format = value_option(warn_format, 1, warn_format, 1,
nowarn_format, 0, Opts),
enabled_warnings = Enabled,
file = File,
types = default_types()
}.
%% is_warn_enabled(Category, St) -> boolean().
%% Check whether a warning of category Category is enabled.
is_warn_enabled(Type, #lint{enabled_warnings=Enabled}) ->
ordsets:is_element(Type, Enabled).
%% return_status(State) ->
%% {ok,[Warning]} | {error,[Error],[Warning]}
%% Pack errors and warnings properly and return ok | error.
return_status(St) ->
Ws = pack_warnings(St#lint.warnings),
case pack_errors(St#lint.errors) of
[] -> {ok,Ws};
Es -> {error,Es,Ws}
end.
%% pack_errors([{File,ErrD}]) -> [{File,[ErrD]}].
%% Sort on (reversed) insertion order.
pack_errors(Es) ->
{Es1,_} = mapfoldl(fun ({File,E}, I) -> {{File,{I,E}}, I-1} end, -1, Es),
map(fun ({File,EIs}) -> {File, map(fun ({_I,E}) -> E end, EIs)} end,
pack_warnings(Es1)).
%% pack_warnings([{File,ErrD}]) -> [{File,[ErrD]}]
%% Sort on line number.
pack_warnings(Ws) ->
[{File,lists:sort([W || {F,W} <- Ws, F =:= File])} ||
File <- lists:usort([F || {F,_} <- Ws])].
%% add_error(ErrorDescriptor, State) -> State'
%% add_error(Line, Error, State) -> State'
%% add_warning(ErrorDescriptor, State) -> State'
%% add_warning(Line, Error, State) -> State'
add_error(E, St) -> St#lint{errors=[{St#lint.file,E}|St#lint.errors]}.
add_error(FileLine, E, St) ->
{File,Location} = loc(FileLine),
add_error({Location,erl_lint,E}, St#lint{file = File}).
add_warning(W, St) -> St#lint{warnings=[{St#lint.file,W}|St#lint.warnings]}.
add_warning(FileLine, W, St) ->
{File,Location} = loc(FileLine),
add_warning({Location,erl_lint,W}, St#lint{file = File}).
loc(L) ->
case erl_parse:get_attribute(L, location) of
{location,{{File,Line},Column}} ->
{File,{Line,Column}};
{location,{File,Line}} ->
{File,Line}
end.
%% forms([Form], State) -> State'
forms(Forms0, St0) ->
Forms = eval_file_attribute(Forms0, St0),
Locals = local_functions(Forms),
AutoImportSuppressed = auto_import_suppressed(St0#lint.compile),
StDeprecated = disallowed_compile_flags(Forms,St0),
%% Line numbers are from now on pairs {File,Line}.
St1 = includes_qlc_hrl(Forms, StDeprecated#lint{locals = Locals,
no_auto = AutoImportSuppressed}),
St2 = bif_clashes(Forms, St1),
St3 = not_deprecated(Forms, St2),
St4 = foldl(fun form/2, pre_scan(Forms, St3), Forms),
post_traversal_check(Forms, St4).
pre_scan([{function,_L,new,_A,_Cs} | Fs], St) ->
pre_scan(Fs, St#lint{new=true});
pre_scan([{attribute,_L,extends,M} | Fs], St) when is_atom(M) ->
pre_scan(Fs, St#lint{extends=true});
pre_scan([{attribute,L,compile,C} | Fs], St) ->
case is_warn_enabled(export_all, St) andalso
member(export_all, lists:flatten([C])) of
true ->
pre_scan(Fs, add_warning(L, export_all, St));
false ->
pre_scan(Fs, St)
end;
pre_scan([_ | Fs], St) ->
pre_scan(Fs, St);
pre_scan([], St) ->
St.
includes_qlc_hrl(Forms, St) ->
%% QLC calls erl_lint several times, sometimes with the compile
%% attribute removed. The file attribute, however, is left as is.
QH = [File || {attribute,_,file,{File,_line}} <- Forms,
filename:basename(File) =:= "qlc.hrl"],
St#lint{xqlc = QH =/= []}.
eval_file_attribute(Forms, St) ->
eval_file_attr(Forms, St#lint.file).
eval_file_attr([{attribute,_L,file,{File,_Line}}=Form | Forms], _File) ->
[Form | eval_file_attr(Forms, File)];
eval_file_attr([Form0 | Forms], File) ->
Form = zip_file_and_line(Form0, File),
[Form | eval_file_attr(Forms, File)];
eval_file_attr([], _File) ->
[].
zip_file_and_line(T, File) ->
F0 = fun(Line) -> {File,Line} end,
F = fun(L) -> erl_parse:set_line(L, F0) end,
modify_line(T, F).
%% form(Form, State) -> State'
%% Check a form returning the updated State. Handle generic cases here.
form({error,E}, St) -> add_error(E, St);
form({warning,W}, St) -> add_warning(W, St);
form({attribute,_L,file,{File,_Line}}, St) ->
St#lint{file = File};
form({attribute,_L,compile,_}, St) ->
St;
form(Form, #lint{state=State}=St) ->
case State of
start -> start_state(Form, St);
attribute -> attribute_state(Form, St);
function -> function_state(Form, St)
end.
%% start_state(Form, State) -> State'
start_state({attribute,L,module,{M,Ps}}, St) ->
St1 = set_module(M, L, St),
Arity = length(Ps),
Ps1 = if is_atom(St1#lint.extends) ->
['BASE', 'THIS' | Ps];
true ->
['THIS' | Ps]
end,
Vt = orddict:from_list([{V, {bound, used, []}} || V <- Ps1]),
St2 = add_instance(Arity, St1),
St3 = ensure_new(Arity, St2),
St3#lint{state=attribute, extends=[], global_vt=Vt};
start_state({attribute,L,module,M}, St) ->
St1 = set_module(M, L, St),
St1#lint{state=attribute, extends=[]};
start_state(Form, St) ->
St1 = add_error(element(2, Form), undefined_module, St),
attribute_state(Form, St1#lint{state=attribute, extends=[]}).
set_module(M, L, St) ->
M1 = package_to_string(M),
case packages:is_valid(M1) of
true ->
St#lint{module=list_to_atom(M1),
package=packages:strip_last(M1)};
false ->
add_error(L, {bad_module_name, M1}, St)
end.
ensure_new(Arity, St) ->
case St#lint.new of
true ->
St;
false ->
add_func(new, Arity, St)
end.
add_instance(Arity, St) ->
A = Arity + (if is_atom(St#lint.extends) -> 1; true -> 0 end),
add_func(instance, A, St).
add_func(Name, Arity, St) ->
F = {Name, Arity},
St#lint{exports = gb_sets:add_element(F, St#lint.exports),
defined = gb_sets:add_element(F, St#lint.defined)}.
%% attribute_state(Form, State) ->
%% State'
attribute_state({attribute,_L,module,_M}, #lint{module=[]}=St) ->
St;
attribute_state({attribute,L,module,_M}, St) ->
add_error(L, redefine_module, St);
attribute_state({attribute,L,extends,M}, #lint{module=M}=St) when is_atom(M) ->
add_error(L, extends_self, St);
attribute_state({attribute,_L,extends,M}, #lint{extends=[]}=St)
when is_atom(M) ->
St#lint{extends=M};
attribute_state({attribute,L,extends,M}, St) when is_atom(M) ->
add_error(L, redefine_extends, St);
attribute_state({attribute,L,extends,_M}, St) ->
add_error(L, invalid_extends, St);
attribute_state({attribute,L,export,Es}, St) ->
export(L, Es, St);
attribute_state({attribute,L,export_type,Es}, St) ->
export_type(L, Es, St);
attribute_state({attribute,L,import,Is}, St) ->
import(L, Is, St);
attribute_state({attribute,L,record,{Name,Fields}}, St) ->
record_def(L, Name, Fields, St);
attribute_state({attribute,La,behaviour,Behaviour}, St) ->
St#lint{behaviour=St#lint.behaviour ++ [{La,Behaviour}]};
attribute_state({attribute,La,behavior,Behaviour}, St) ->
St#lint{behaviour=St#lint.behaviour ++ [{La,Behaviour}]};
attribute_state({attribute,L,type,{TypeName,TypeDef,Args}}, St) ->
type_def(type, L, TypeName, TypeDef, Args, St);
attribute_state({attribute,L,opaque,{TypeName,TypeDef,Args}}, St) ->
type_def(opaque, L, TypeName, TypeDef, Args, St);
attribute_state({attribute,L,spec,{Fun,Types}}, St) ->
spec_decl(L, Fun, Types, St);
attribute_state({attribute,L,on_load,Val}, St) ->
on_load(L, Val, St);
attribute_state({attribute,_L,_Other,_Val}, St) -> % Ignore others
St;
attribute_state(Form, St) ->
function_state(Form, St#lint{state=function}).
%% function_state(Form, State) ->
%% State'
%% Allow for record, type and opaque type definitions and spec
%% declarations to be intersperced within function definitions.
function_state({attribute,L,record,{Name,Fields}}, St) ->
record_def(L, Name, Fields, St);
function_state({attribute,L,type,{TypeName,TypeDef,Args}}, St) ->
type_def(type, L, TypeName, TypeDef, Args, St);
function_state({attribute,L,opaque,{TypeName,TypeDef,Args}}, St) ->
type_def(opaque, L, TypeName, TypeDef, Args, St);
function_state({attribute,L,spec,{Fun,Types}}, St) ->
spec_decl(L, Fun, Types, St);
function_state({attribute,La,Attr,_Val}, St) ->
add_error(La, {attribute,Attr}, St);
function_state({function,L,N,A,Cs}, St) ->
function(L, N, A, Cs, St);
function_state({rule,L,_N,_A,_Cs}, St) ->
add_error(L, {mnemosyne,"rule"}, St);
function_state({eof,L}, St) -> eof(L, St).
%% eof(LastLine, State) ->
%% State'
eof(_Line, St0) ->
St0.
%% bif_clashes(Forms, State0) -> State.
bif_clashes(Forms, St) ->
Nowarn = nowarn_function(nowarn_bif_clash, St#lint.compile),
Clashes0 = [{Name,Arity} || {function,_L,Name,Arity,_Cs} <- Forms,
erl_internal:bif(Name, Arity)],
Clashes = ordsets:subtract(ordsets:from_list(Clashes0), Nowarn),
St#lint{clashes=Clashes}.
%% not_deprecated(Forms, State0) -> State
not_deprecated(Forms, St0) ->
%% There are no line numbers in St0#lint.compile.
MFAsL = [{MFA,L} ||
{attribute, L, compile, Args} <- Forms,
{nowarn_deprecated_function, MFAs0} <- lists:flatten([Args]),
MFA <- lists:flatten([MFAs0])],
Nowarn = [MFA || {MFA,_L} <- MFAsL],
Bad = [MFAL || {{M,F,A},_L}=MFAL <- MFAsL,
otp_internal:obsolete(M, F, A) =:= no],
St1 = func_line_warning(bad_nowarn_deprecated_function, Bad, St0),
St1#lint{not_deprecated = ordsets:from_list(Nowarn)}.
%% The nowarn_bif_clash directive is not only deprecated, it's actually an error from R14A
disallowed_compile_flags(Forms, St0) ->
%% There are (still) no line numbers in St0#lint.compile.
Errors0 = [ {St0#lint.file,{L,erl_lint,disallowed_nowarn_bif_clash}} ||
{attribute,[{line,{_,L}}],compile,nowarn_bif_clash} <- Forms ],
Errors1 = [ {St0#lint.file,{L,erl_lint,disallowed_nowarn_bif_clash}} ||
{attribute,[{line,{_,L}}],compile,{nowarn_bif_clash, {_,_}}} <- Forms ],
Disabled = (not is_warn_enabled(bif_clash, St0)),
Errors = if
Disabled andalso Errors0 =:= [] ->
[{St0#lint.file,{erl_lint,disallowed_nowarn_bif_clash}} | St0#lint.errors];
Disabled ->
Errors0 ++ Errors1 ++ St0#lint.errors;
true ->
Errors1 ++ St0#lint.errors
end,
St0#lint{errors=Errors}.
%% post_traversal_check(Forms, State0) -> State.
%% Do some further checking after the forms have been traversed and
%% data about calls etc. have been collected.
post_traversal_check(Forms, St0) ->
St1 = check_behaviour(St0),
St2 = check_deprecated(Forms, St1),
St3 = check_imports(Forms, St2),
St4 = check_inlines(Forms, St3),
St5 = check_undefined_functions(St4),
St6 = check_unused_functions(Forms, St5),
St7 = check_bif_clashes(Forms, St6),
St8 = check_specs_without_function(St7),
St9 = check_functions_without_spec(Forms, St8),
StA = check_undefined_types(St9),
StB = check_unused_types(Forms, StA),
StC = check_untyped_records(Forms, StB),
StD = check_on_load(StC),
check_unused_records(Forms, StD).
%% check_behaviour(State0) -> State
%% Check that the behaviour attribute is valid.
check_behaviour(St0) ->
behaviour_check(St0#lint.behaviour, St0).
%% behaviour_check([{Line,Behaviour}], State) -> State'
%% Check behaviours for existence and defined functions.
behaviour_check(Bs, St0) ->
{AllBfs,St1} = all_behaviour_callbacks(Bs, [], St0),
St = behaviour_missing_callbacks(AllBfs, St1),
behaviour_conflicting(AllBfs, St).
all_behaviour_callbacks([{Line,B}|Bs], Acc, St0) ->
{Bfs0,St} = behaviour_callbacks(Line, B, St0),
all_behaviour_callbacks(Bs, [{{Line,B},Bfs0}|Acc], St);
all_behaviour_callbacks([], Acc, St) -> {reverse(Acc),St}.
behaviour_callbacks(Line, B, St0) ->
try B:behaviour_info(callbacks) of
Funcs when is_list(Funcs) ->
All = all(fun({FuncName, Arity}) ->
is_atom(FuncName) andalso is_integer(Arity);
({FuncName, Arity, Spec}) ->
is_atom(FuncName) andalso is_integer(Arity)
andalso is_list(Spec);
(_Other) ->
false
end,
Funcs),
MaybeRemoveSpec = fun({_F,_A}=FA) -> FA;
({F,A,_S}) -> {F,A};
(Other) -> Other
end,
if
All =:= true ->
{[MaybeRemoveSpec(F) || F <- Funcs], St0};
true ->
St1 = add_warning(Line,
{ill_defined_behaviour_callbacks,B},
St0),
{[], St1}
end;
undefined ->
St1 = add_warning(Line, {undefined_behaviour_callbacks,B}, St0),
{[], St1};
_Other ->
St1 = add_warning(Line, {ill_defined_behaviour_callbacks,B}, St0),
{[], St1}
catch
_:_ ->
St1 = add_warning(Line, {undefined_behaviour,B}, St0),
{[], St1}
end.
behaviour_missing_callbacks([{{Line,B},Bfs}|T], #lint{exports=Exp}=St0) ->
Missing = ordsets:subtract(ordsets:from_list(Bfs), gb_sets:to_list(Exp)),
St = foldl(fun (F, S0) ->
add_warning(Line, {undefined_behaviour_func,F,B}, S0)
end, St0, Missing),
behaviour_missing_callbacks(T, St);
behaviour_missing_callbacks([], St) -> St.
behaviour_conflicting(AllBfs, St) ->
R0 = sofs:relation(AllBfs, [{item,[callback]}]),
R1 = sofs:family_to_relation(R0),
R2 = sofs:converse(R1),
R3 = sofs:relation_to_family(R2),
R4 = sofs:family_specification(fun(S) -> sofs:no_elements(S) > 1 end, R3),
R = sofs:to_external(R4),
behaviour_add_conflicts(R, St).
behaviour_add_conflicts([{Cb,[{FirstLoc,FirstB}|Cs]}|T], St0) ->
FirstL = element(2, loc(FirstLoc)),
St = behaviour_add_conflict(Cs, Cb, FirstL, FirstB, St0),
behaviour_add_conflicts(T, St);
behaviour_add_conflicts([], St) -> St.
behaviour_add_conflict([{Line,B}|Cs], Cb, FirstL, FirstB, St0) ->
St = add_warning(Line, {conflicting_behaviours,Cb,B,FirstL,FirstB}, St0),
behaviour_add_conflict(Cs, Cb, FirstL, FirstB, St);
behaviour_add_conflict([], _, _, _, St) -> St.
%% check_deprecated(Forms, State0) -> State
check_deprecated(Forms, St0) ->
%% Get the correct list of exported functions.
Exports = case member(export_all, St0#lint.compile) of
true -> St0#lint.defined;
false -> St0#lint.exports
end,
X = gb_sets:to_list(Exports),
#lint{module = Mod} = St0,
Bad = [{E,L} || {attribute, L, deprecated, Depr} <- Forms,
D <- lists:flatten([Depr]),
E <- depr_cat(D, X, Mod)],
foldl(fun ({E,L}, St1) ->
add_error(L, E, St1)
end, St0, Bad).
depr_cat({F, A, Flg}=D, X, Mod) ->
case deprecated_flag(Flg) of
false -> [{invalid_deprecated,D}];
true -> depr_fa(F, A, X, Mod)
end;
depr_cat({F, A}, X, Mod) ->
depr_fa(F, A, X, Mod);
depr_cat(module, _X, _Mod) ->
[];
depr_cat(D, _X, _Mod) ->
[{invalid_deprecated,D}].
depr_fa('_', '_', _X, _Mod) ->
[];
depr_fa(F, '_', X, _Mod) when is_atom(F) ->
%% Don't use this syntax for built-in functions.
case lists:filter(fun({F1,_}) -> F1 =:= F end, X) of
[] -> [{bad_deprecated,{F,'_'}}];
_ -> []
end;
depr_fa(F, A, X, Mod) when is_atom(F), is_integer(A), A >= 0 ->
case lists:member({F,A}, X) of
true -> [];
false ->
case erlang:is_builtin(Mod, F, A) of
true -> [];
false -> [{bad_deprecated,{F,A}}]
end
end;
depr_fa(F, A, _X, _Mod) ->
[{invalid_deprecated,{F,A}}].
deprecated_flag(next_version) -> true;
deprecated_flag(next_major_release) -> true;
deprecated_flag(eventually) -> true;
deprecated_flag(_) -> false.
%% check_imports(Forms, State0) -> State
check_imports(Forms, St0) ->
case is_warn_enabled(unused_import, St0) of
false ->
St0;
true ->
Usage = St0#lint.usage,
Unused = ordsets:subtract(St0#lint.imports, Usage#usage.imported),
Imports = [{{FA,list_to_atom(package_to_string(Mod))},L}
|| {attribute,L,import,{Mod,Fs}} <- Forms,
FA <- lists:usort(Fs)],
Bad = [{FM,L} || FM <- Unused, {FM2,L} <- Imports, FM =:= FM2],
func_line_warning(unused_import, Bad, St0)
end.
%% check_inlines(Forms, State0) -> State
check_inlines(Forms, St0) ->
check_option_functions(Forms, inline, bad_inline, St0).
%% check_unused_functions(Forms, State0) -> State
check_unused_functions(Forms, St0) ->
St1 = check_option_functions(Forms, nowarn_unused_function,
bad_nowarn_unused_function, St0),
Opts = St1#lint.compile,
case member(export_all, Opts) orelse
not is_warn_enabled(unused_function, St1) of
true ->
St1;
false ->
Nowarn = nowarn_function(nowarn_unused_function, Opts),
Usage = St1#lint.usage,
Used = reached_functions(initially_reached(St1),
Usage#usage.calls),
UsedOrNowarn = ordsets:union(Used, Nowarn),
Unused = ordsets:subtract(gb_sets:to_list(St1#lint.defined),
UsedOrNowarn),
Functions = [{{N,A},L} || {function,L,N,A,_} <- Forms],
Bad = [{FA,L} || FA <- Unused, {FA2,L} <- Functions, FA =:= FA2],
func_line_warning(unused_function, Bad, St1)
end.
initially_reached(#lint{exports=Exp,on_load=OnLoad}) ->
OnLoad ++ gb_sets:to_list(Exp).
%% reached_functions(RootSet, CallRef) -> [ReachedFunc].
%% reached_functions(RootSet, CallRef, [ReachedFunc]) -> [ReachedFunc].
reached_functions(Root, Ref) ->
reached_functions(Root, [], Ref, gb_sets:empty()).
reached_functions([R|Rs], More0, Ref, Reached0) ->
case gb_sets:is_element(R, Reached0) of
true -> reached_functions(Rs, More0, Ref, Reached0);
false ->
Reached = gb_sets:add_element(R, Reached0), %It IS reached
case dict:find(R, Ref) of
{ok,More} -> reached_functions(Rs, [More|More0], Ref, Reached);
error -> reached_functions(Rs, More0, Ref, Reached)
end
end;
reached_functions([], [_|_]=More, Ref, Reached) ->
reached_functions(lists:append(More), [], Ref, Reached);
reached_functions([], [], _Ref, Reached) -> gb_sets:to_list(Reached).
%% check_undefined_functions(State0) -> State
check_undefined_functions(#lint{called=Called0,defined=Def0}=St0) ->
Called = sofs:relation(Called0, [{func,location}]),
Def = sofs:from_external(gb_sets:to_list(Def0), [func]),
Undef = sofs:to_external(sofs:drestriction(Called, Def)),
foldl(fun ({NA,L}, St) ->
add_error(L, {undefined_function,NA}, St)
end, St0, Undef).
%% check_undefined_types(State0) -> State
check_undefined_types(#lint{usage=Usage,types=Def}=St0) ->
Used = Usage#usage.used_types,
UTAs = dict:fetch_keys(Used),
Undef = [{TA,dict:fetch(TA, Used)} || TA <- UTAs, not dict:is_key(TA, Def)],
foldl(fun ({TA,L}, St) ->
add_error(L, {undefined_type,TA}, St)
end, St0, Undef).
%% check_bif_clashes(Forms, State0) -> State
check_bif_clashes(Forms, St0) ->
%% St0#lint.defined is now complete.
check_option_functions(Forms, nowarn_bif_clash,
bad_nowarn_bif_clash, St0).
check_option_functions(Forms, Tag0, Type, St0) ->
%% There are no line numbers in St0#lint.compile.
FAsL = [{FA,L} || {attribute, L, compile, Args} <- Forms,
{Tag, FAs0} <- lists:flatten([Args]),
Tag0 =:= Tag,
FA <- lists:flatten([FAs0])],
DefFunctions = (gb_sets:to_list(St0#lint.defined) -- pseudolocals()) ++
[{F,A} || {{F,A},_} <- orddict:to_list(St0#lint.imports)],
Bad = [{FA,L} || {FA,L} <- FAsL, not member(FA, DefFunctions)],
func_line_error(Type, Bad, St0).
nowarn_function(Tag, Opts) ->
ordsets:from_list([FA || {Tag1,FAs} <- Opts,
Tag1 =:= Tag,
FA <- lists:flatten([FAs])]).
func_line_warning(Type, Fs, St) ->
foldl(fun ({F,Line}, St0) -> add_warning(Line, {Type,F}, St0) end, St, Fs).
func_line_error(Type, Fs, St) ->
foldl(fun ({F,Line}, St0) -> add_error(Line, {Type,F}, St0) end, St, Fs).
check_untyped_records(Forms, St0) ->
case is_warn_enabled(untyped_record, St0) of
true ->
%% Use the names of all records *defined* in the module (not used)
RecNames = dict:fetch_keys(St0#lint.records),
%% these are the records with field(s) containing type info
TRecNames = [Name ||
{attribute,_,type,{{record,Name},Fields,_}} <- Forms,
lists:all(fun ({typed_record_field,_,_}) -> true;
(_) -> false
end, Fields)],
foldl(fun (N, St) ->
{L, Fields} = dict:fetch(N, St0#lint.records),
case Fields of
[] -> St; % exclude records with no fields
[_|_] -> add_warning(L, {untyped_record, N}, St)
end
end, St0, RecNames -- TRecNames);
false ->
St0
end.
check_unused_records(Forms, St0) ->
AttrFiles = [File || {attribute,_L,file,{File,_Line}} <- Forms],
case {is_warn_enabled(unused_record, St0),AttrFiles} of
{true,[FirstFile|_]} ->
%% The check is a bit imprecise in that uses from unused
%% functions count.
Usage = St0#lint.usage,
UsedRecords = sets:to_list(Usage#usage.used_records),
URecs = foldl(fun (Used, Recs) ->
dict:erase(Used, Recs)
end, St0#lint.records, UsedRecords),
Unused = [{Name,FileLine} ||
{Name,{FileLine,_Fields}} <- dict:to_list(URecs),
element(1, loc(FileLine)) =:= FirstFile],
foldl(fun ({N,L}, St) ->
add_warning(L, {unused_record, N}, St)
end, St0, Unused);
_ ->
St0
end.
%% For storing the import list we use the orddict module.
%% We know an empty set is [].
-spec export(line(), [fa()], lint_state()) -> lint_state().
%% Mark functions as exported, also as called from the export line.
export(Line, Es, #lint{exports = Es0, called = Called} = St0) ->
{Es1,C1,St1} =
foldl(fun (NA, {E,C,St2}) ->
St = case gb_sets:is_element(NA, E) of
true ->
Warn = {duplicated_export,NA},
add_warning(Line, Warn, St2);
false ->
St2
end,
{gb_sets:add_element(NA, E), [{NA,Line}|C], St}
end,
{Es0,Called,St0}, Es),
St1#lint{exports = Es1, called = C1}.
-spec export_type(line(), [ta()], lint_state()) -> lint_state().
%% Mark types as exported, also as called from the export line.
export_type(Line, ETs, #lint{exp_types = ETs0} = St0) ->
{ETs1,St1} =
foldl(fun (TA, {E,St2}) ->
St = case gb_sets:is_element(TA, E) of
true ->
Warn = {duplicated_export_type,TA},
add_warning(Line, Warn, St2);
false ->
St2
end,
{gb_sets:add_element(TA, E), St}
end,
{ETs0,St0}, ETs),
St1#lint{exp_types = ETs1}.
-type import() :: {module(), [fa()]} | module().
-spec import(line(), import(), lint_state()) -> lint_state().
import(Line, {Mod,Fs}, St) ->
Mod1 = package_to_string(Mod),
case packages:is_valid(Mod1) of
true ->
Mfs = ordsets:from_list(Fs),
case check_imports(Line, Mfs, St#lint.imports) of
[] ->
St#lint{imports=add_imports(list_to_atom(Mod1), Mfs,
St#lint.imports)};
Efs ->
{Err, St1} =
foldl(fun ({bif,{F,A},_}, {Err,St0}) ->
%% BifClash - import directive
Warn = is_warn_enabled(bif_clash, St0)
and (not bif_clash_specifically_disabled(St0,{F,A})),
AutoImpSup = is_autoimport_suppressed(St0#lint.no_auto,{F,A}),
OldBif = erl_internal:old_bif(F,A),
{Err,if
Warn and (not AutoImpSup) and OldBif ->
add_error
(Line,
{redefine_old_bif_import, {F,A}},
St0);
Warn and (not AutoImpSup) ->
add_warning
(Line,
{redefine_bif_import, {F,A}},
St0);
true ->
St0
end};
(Ef, {_Err,St0}) ->
{true,add_error(Line,
{redefine_import,Ef},
St0)}
end,
{false,St}, Efs),
if
not Err ->
St1#lint{imports=
add_imports(list_to_atom(Mod1), Mfs,
St#lint.imports)};
true ->
St1
end
end;
false ->
add_error(Line, {bad_module_name, Mod1}, St)
end;
import(Line, Mod, St) ->
Mod1 = package_to_string(Mod),
case packages:is_valid(Mod1) of
true ->
Key = list_to_atom(packages:last(Mod1)),
Imps = St#lint.mod_imports,
%%% case dict:is_key(Key, Imps) of
%%% true ->
%%% M = packages:last(Mod1),
%%% P = packages:strip_last(Mod1),
%%% add_error(Line, {redefine_mod_import, M, P}, St);
%%% false ->
%%% St#lint{mod_imports =
%%% dict:store(Key, list_to_atom(Mod1), Imps)}
%%% end;
St#lint{mod_imports = dict:store(Key, list_to_atom(Mod1),
Imps)};
false ->
add_error(Line, {bad_module_name, Mod1}, St)
end.
check_imports(_Line, Fs, Is) ->
foldl(fun (F, Efs) ->
case orddict:find(F, Is) of
{ok,Mod} -> [{F,Mod}|Efs];
error ->
{N,A} = F,
case erl_internal:bif(N, A) of
true ->
[{bif,F,erlang}|Efs];
false ->
Efs
end
end end, [], Fs).
add_imports(Mod, Fs, Is) ->
foldl(fun (F, Is0) -> orddict:store(F, Mod, Is0) end, Is, Fs).
-spec imported(atom(), arity(), lint_state()) -> {'yes',module()} | 'no'.
imported(F, A, St) ->
case orddict:find({F,A}, St#lint.imports) of
{ok,Mod} -> {yes,Mod};
error -> no
end.
-spec on_load(line(), fa(), lint_state()) -> lint_state().
%% Check an on_load directive and remember it.
on_load(Line, {Name,Arity}=Fa, #lint{on_load=OnLoad0}=St0)
when is_atom(Name), is_integer(Arity) ->
%% Always add the function name (even if there is a problem),
%% to avoid irrelevant warnings for unused functions.
St = St0#lint{on_load=[Fa|OnLoad0],on_load_line=Line},
case St of
#lint{on_load=[{_,0}]} ->
%% This is the first on_load attribute seen in the module
%% and it has the correct arity.
St;
#lint{on_load=[{_,_}]} ->
%% Wrong arity.
add_error(Line, {bad_on_load_arity,Fa}, St);
#lint{on_load=[_,_|_]} ->
%% Multiple on_load attributes.
add_error(Line, multiple_on_loads, St)
end;
on_load(Line, Val, St) ->
%% Bad syntax.
add_error(Line, {bad_on_load,Val}, St).
check_on_load(#lint{defined=Defined,on_load=[{_,0}=Fa],
on_load_line=Line}=St) ->
case gb_sets:is_member(Fa, Defined) of
true -> St;
false -> add_error(Line, {undefined_on_load,Fa}, St)
end;
check_on_load(St) -> St.
-spec call_function(line(), atom(), arity(), lint_state()) -> lint_state().
%% Add to both called and calls.
call_function(Line, F, A, #lint{usage=Usage0,called=Cd,func=Func}=St) ->
#usage{calls = Cs} = Usage0,
NA = {F,A},
Usage = case Cs of
undefined -> Usage0;
_ -> Usage0#usage{calls=dict:append(Func, NA, Cs)}
end,
St#lint{called=[{NA,Line}|Cd], usage=Usage}.
%% function(Line, Name, Arity, Clauses, State) -> State.
function(Line, instance, _Arity, _Cs, St) when St#lint.global_vt =/= [] ->
add_error(Line, define_instance, St);
function(Line, Name, Arity, Cs, St0) ->
St1 = define_function(Line, Name, Arity, St0#lint{func={Name,Arity}}),
clauses(Cs, St1#lint.global_vt, St1).
-spec define_function(line(), atom(), arity(), lint_state()) -> lint_state().
define_function(Line, Name, Arity, St0) ->
St1 = keyword_warning(Line, Name, St0),
NA = {Name,Arity},
case gb_sets:is_member(NA, St1#lint.defined) of
true ->
add_error(Line, {redefine_function,NA}, St1);
false ->
St2 = St1#lint{defined=gb_sets:add_element(NA, St1#lint.defined)},
case imported(Name, Arity, St2) of
{yes,_M} -> add_error(Line, {define_import,NA}, St2);
no -> St2
end
end.
%% clauses([Clause], VarTable, State) -> {VarTable, State}.
clauses(Cs, Vt, St) ->
foldl(fun (C, St0) ->
{_,St1} = clause(C, Vt, St0),
St1
end, St, Cs).
clause({clause,_Line,H,G,B}, Vt0, St0) ->
{Hvt,Binvt,St1} = head(H, Vt0, St0),
%% Cannot ignore BinVt since "binsize variables" may have been used.
Vt1 = vtupdate(Hvt, vtupdate(Binvt, Vt0)),
{Gvt,St2} = guard(G, Vt1, St1),
Vt2 = vtupdate(Gvt, Vt1),
{Bvt,St3} = exprs(B, Vt2, St2),
Upd = vtupdate(Bvt, Vt2),
check_unused_vars(Upd, Vt0, St3).
%% head([HeadPattern], VarTable, State) ->
%% {VarTable,BinVarTable,State}
%% Check a patterns in head returning "all" variables. Not updating the
%% known variable list will result in multiple error messages/warnings.
head(Ps, Vt, St0) ->
head(Ps, Vt, Vt, St0). % Old = Vt
head([P|Ps], Vt, Old, St0) ->
{Pvt,Bvt1,St1} = pattern(P, Vt, Old, [], St0),
{Psvt,Bvt2,St2} = head(Ps, Vt, Old, St1),
{vtmerge_pat(Pvt, Psvt),vtmerge_pat(Bvt1,Bvt2),St2};
head([], _Vt, _Env, St) -> {[],[],St}.
%% pattern(Pattern, VarTable, Old, BinVarTable, State) ->
%% {UpdVarTable,BinVarTable,State}.
%% Check pattern return variables. Old is the set of variables used for
%% deciding whether an occurrence is a binding occurrence or a use, and
%% VarTable is the set of variables used for arguments to binary
%% patterns. UpdVarTable is updated when same variable in VarTable is
%% used in the size part of a bit segment. All other information about
%% used variables are recorded in BinVarTable. The caller can then decide
%% what to do with it depending on whether variables in the pattern shadow
%% variabler or not. This separation is one way of dealing with these:
%% A = 4, fun(<<A:A>>) -> % A #2 unused
%% A = 4, fun(<<A:8,16:A>>) -> % A #1 unused
pattern(P, Vt, St) ->
pattern(P, Vt, Vt, [], St). % Old = Vt
pattern({var,_Line,'_'}, _Vt, _Old, _Bvt, St) ->
{[],[],St}; %Ignore anonymous variable
pattern({var,Line,V}, _Vt, Old, Bvt, St) ->
pat_var(V, Line, Old, Bvt, St);
pattern({char,_Line,_C}, _Vt, _Old, _Bvt, St) -> {[],[],St};
pattern({integer,_Line,_I}, _Vt, _Old, _Bvt, St) -> {[],[],St};
pattern({float,_Line,_F}, _Vt, _Old, _Bvt, St) -> {[],[],St};
pattern({atom,Line,A}, _Vt, _Old, _Bvt, St) ->
{[],[],keyword_warning(Line, A, St)};
pattern({string,_Line,_S}, _Vt, _Old, _Bvt, St) -> {[],[],St};
pattern({nil,_Line}, _Vt, _Old, _Bvt, St) -> {[],[],St};
pattern({cons,_Line,H,T}, Vt, Old, Bvt, St0) ->
{Hvt,Bvt1,St1} = pattern(H, Vt, Old, Bvt, St0),
{Tvt,Bvt2,St2} = pattern(T, Vt, Old, Bvt, St1),
{vtmerge_pat(Hvt, Tvt),vtmerge_pat(Bvt1,Bvt2),St2};
pattern({tuple,_Line,Ps}, Vt, Old, Bvt, St) ->
pattern_list(Ps, Vt, Old, Bvt, St);
%%pattern({struct,_Line,_Tag,Ps}, Vt, Old, Bvt, St) ->
%% pattern_list(Ps, Vt, Old, Bvt, St);
pattern({record_index,Line,Name,Field}, _Vt, _Old, _Bvt, St) ->
{Vt1,St1} =
check_record(Line, Name, St,
fun (Dfs, St1) ->
pattern_field(Field, Name, Dfs, St1)
end),
{Vt1,[],St1};
pattern({record_field,Line,_,_}=M, _Vt, _Old, _Bvt, St0) ->
case expand_package(M, St0) of
{error, St1} ->
{[],[],add_error(Line, illegal_expr, St1)};
{_, St1} ->
{[],[],St1}
end;
pattern({record,Line,Name,Pfs}, Vt, Old, Bvt, St) ->
case dict:find(Name, St#lint.records) of
{ok,{_Line,Fields}} ->
St1 = used_record(Name, St),
pattern_fields(Pfs, Name, Fields, Vt, Old, Bvt, St1);
error -> {[],[],add_error(Line, {undefined_record,Name}, St)}
end;
pattern({bin,_,Fs}, Vt, Old, Bvt, St) ->
pattern_bin(Fs, Vt, Old, Bvt, St);
pattern({op,_Line,'++',{nil,_},R}, Vt, Old, Bvt, St) ->
pattern(R, Vt, Old, Bvt, St);
pattern({op,_Line,'++',{cons,Li,{char,_L2,_C},T},R}, Vt, Old, Bvt, St) ->
pattern({op,Li,'++',T,R}, Vt, Old, Bvt, St); %Char unimportant here
pattern({op,_Line,'++',{cons,Li,{integer,_L2,_I},T},R}, Vt, Old, Bvt, St) ->
pattern({op,Li,'++',T,R}, Vt, Old, Bvt, St); %Weird, but compatible!
pattern({op,_Line,'++',{string,_Li,_S},R}, Vt, Old, Bvt, St) ->
pattern(R, Vt, Old, Bvt, St); %String unimportant here
pattern({match,_Line,Pat1,Pat2}, Vt, Old, Bvt, St0) ->
{Lvt,Bvt1,St1} = pattern(Pat1, Vt, Old, Bvt, St0),
{Rvt,Bvt2,St2} = pattern(Pat2, Vt, Old, Bvt, St1),
St3 = reject_bin_alias(Pat1, Pat2, St2),
{vtmerge_pat(Lvt, Rvt),vtmerge_pat(Bvt1,Bvt2),St3};
%% Catch legal constant expressions, including unary +,-.
pattern(Pat, _Vt, _Old, _Bvt, St) ->
case is_pattern_expr(Pat) of
true -> {[],[],St};
false -> {[],[],add_error(element(2, Pat), illegal_pattern, St)}
end.
pattern_list(Ps, Vt, Old, Bvt0, St) ->
foldl(fun (P, {Psvt,Bvt,St0}) ->
{Pvt,Bvt1,St1} = pattern(P, Vt, Old, Bvt0, St0),
{vtmerge_pat(Pvt, Psvt),vtmerge_pat(Bvt,Bvt1),St1}
end, {[],[],St}, Ps).
%% reject_bin_alias(Pat, Expr, St) -> St'
%% Reject aliases for binary patterns at the top level.
reject_bin_alias_expr({bin,_,_}=P, {match,_,P0,E}, St0) ->
St = reject_bin_alias(P, P0, St0),
reject_bin_alias_expr(P, E, St);
reject_bin_alias_expr({match,_,_,_}=P, {match,_,P0,E}, St0) ->
St = reject_bin_alias(P, P0, St0),
reject_bin_alias_expr(P, E, St);
reject_bin_alias_expr(_, _, St) -> St.
%% reject_bin_alias(Pat1, Pat2, St) -> St'
%% Aliases of binary patterns, such as <<A:8>> = <<B:4,C:4>> or even
%% <<A:8>> = <<A:8>>, are not allowed. Traverse the patterns in parallel
%% and generate an error if any binary aliases are found.
%% We generate an error even if is obvious that the overall pattern can't
%% possibly match, for instance, {a,<<A:8>>,c}={x,<<A:8>>} WILL generate an
%% error.
reject_bin_alias({bin,Line,_}, {bin,_,_}, St) ->
add_error(Line, illegal_bin_pattern, St);
reject_bin_alias({cons,_,H1,T1}, {cons,_,H2,T2}, St0) ->
St = reject_bin_alias(H1, H2, St0),
reject_bin_alias(T1, T2, St);
reject_bin_alias({tuple,_,Es1}, {tuple,_,Es2}, St) ->
reject_bin_alias_list(Es1, Es2, St);
reject_bin_alias({record,_,Name1,Pfs1}, {record,_,Name2,Pfs2},
#lint{records=Recs}=St) ->
case {dict:find(Name1, Recs),dict:find(Name2, Recs)} of
{{ok,{_Line1,Fields1}},{ok,{_Line2,Fields2}}} ->
reject_bin_alias_rec(Pfs1, Pfs2, Fields1, Fields2, St);
{_,_} ->
%% One or more non-existing records. (An error messages has
%% already been generated, so we are done here.)
St
end;
reject_bin_alias({match,_,P1,P2}, P, St0) ->
St = reject_bin_alias(P1, P, St0),
reject_bin_alias(P2, P, St);
reject_bin_alias(P, {match,_,_,_}=M, St) ->
reject_bin_alias(M, P, St);
reject_bin_alias(_P1, _P2, St) -> St.
reject_bin_alias_list([E1|Es1], [E2|Es2], St0) ->
St = reject_bin_alias(E1, E2, St0),
reject_bin_alias_list(Es1, Es2, St);
reject_bin_alias_list(_, _, St) -> St.
reject_bin_alias_rec(PfsA0, PfsB0, FieldsA0, FieldsB0, St) ->
%% We treat records as if they have been converted to tuples.
PfsA1 = rbia_field_vars(PfsA0),
PfsB1 = rbia_field_vars(PfsB0),
FieldsA1 = rbia_fields(lists:reverse(FieldsA0), 0, []),
FieldsB1 = rbia_fields(lists:reverse(FieldsB0), 0, []),
FieldsA = sofs:relation(FieldsA1),
PfsA = sofs:relation(PfsA1),
A = sofs:join(FieldsA, 1, PfsA, 1),
FieldsB = sofs:relation(FieldsB1),
PfsB = sofs:relation(PfsB1),
B = sofs:join(FieldsB, 1, PfsB, 1),
C = sofs:join(A, 2, B, 2),
D = sofs:projection({external,fun({_,_,P1,_,P2}) -> {P1,P2} end}, C),
E = sofs:to_external(D),
{Ps1,Ps2} = lists:unzip(E),
reject_bin_alias_list(Ps1, Ps2, St).
rbia_field_vars(Fs) ->
[{Name,Pat} || {record_field,_,{atom,_,Name},Pat} <- Fs].
rbia_fields([{record_field,_,{atom,_,Name},_}|Fs], I, Acc) ->
rbia_fields(Fs, I+1, [{Name,I}|Acc]);
rbia_fields([_|Fs], I, Acc) ->
rbia_fields(Fs, I+1, Acc);
rbia_fields([], _, Acc) -> Acc.
%% is_pattern_expr(Expression) -> boolean().
%% Test if a general expression is a valid pattern expression.
is_pattern_expr(Expr) ->
case is_pattern_expr_1(Expr) of
false -> false;
true ->
%% Expression is syntactically correct - make sure that it
%% also can be evaluated.
case erl_eval:partial_eval(Expr) of
{integer,_,_} -> true;
{char,_,_} -> true;
{float,_,_} -> true;
{atom,_,_} -> true;
_ -> false
end
end.
is_pattern_expr_1({char,_Line,_C}) -> true;
is_pattern_expr_1({integer,_Line,_I}) -> true;
is_pattern_expr_1({float,_Line,_F}) -> true;
is_pattern_expr_1({atom,_Line,_A}) -> true;
is_pattern_expr_1({tuple,_Line,Es}) ->
all(fun is_pattern_expr/1, Es);
is_pattern_expr_1({nil,_Line}) -> true;
is_pattern_expr_1({cons,_Line,H,T}) ->
is_pattern_expr_1(H) andalso is_pattern_expr_1(T);
is_pattern_expr_1({op,_Line,Op,A}) ->
erl_internal:arith_op(Op, 1) andalso is_pattern_expr_1(A);
is_pattern_expr_1({op,_Line,Op,A1,A2}) ->
erl_internal:arith_op(Op, 2) andalso all(fun is_pattern_expr/1, [A1,A2]);
is_pattern_expr_1(_Other) -> false.
%% pattern_bin([Element], VarTable, Old, BinVarTable, State) ->
%% {UpdVarTable,UpdBinVarTable,State}.
%% Check a pattern group. BinVarTable are used binsize variables.
pattern_bin(Es, Vt, Old, Bvt0, St0) ->
{_Sz,Esvt,Bvt,St1} = foldl(fun (E, Acc) ->
pattern_element(E, Vt, Old, Acc)
end,
{0,[],Bvt0,St0}, Es),
{Esvt,Bvt,St1}.
pattern_element({bin_element,Line,{string,_,_},Size,Ts}=Be, Vt,
Old, {Sz,Esvt,Bvt,St0}=Acc) ->
case good_string_size_type(Size, Ts) of
true ->
pattern_element_1(Be, Vt, Old, Acc);
false ->
St = add_error(Line, typed_literal_string, St0),
{Sz,Esvt,Bvt,St}
end;
pattern_element(Be, Vt, Old, Acc) ->
pattern_element_1(Be, Vt, Old, Acc).
pattern_element_1({bin_element,Line,E,Sz0,Ts}, Vt, Old, {Size0,Esvt,Bvt,St0}) ->
{Pevt,Bvt1,St1} = pat_bit_expr(E, Old, Bvt, St0),
%% vtmerge or vtmerge_pat doesn't matter here
{Sz1,Szvt,Bvt2,St2} = pat_bit_size(Sz0, vtmerge(Vt, Esvt), Bvt, St1),
{Sz2,Bt,St3} = bit_type(Line, Sz1, Ts, St2),
{Sz3,St4} = bit_size_check(Line, Sz2, Bt, St3),
Sz4 = case {E,Sz3} of
{{string,_,S},all} -> 8*length(S);
{_,_} -> Sz3
end,
{Size1,St5} = add_bit_size(Line, Sz4, Size0, false, St4),
{Size1,vtmerge(Szvt,vtmerge(Pevt, Esvt)),
vtmerge(Bvt2,vtmerge(Bvt, Bvt1)), St5}.
good_string_size_type(default, default) ->
true;
good_string_size_type(default, Ts) ->
lists:any(fun(utf8) -> true;
(utf16) -> true;
(utf32) -> true;
(_) -> false
end, Ts);
good_string_size_type(_, _) -> false.
%% pat_bit_expr(Pattern, OldVarTable, BinVarTable,State) ->
%% {UpdVarTable,UpdBinVarTable,State}.
%% Check pattern bit expression, only allow really valid patterns!
pat_bit_expr({var,_,'_'}, _Old, _Bvt, St) -> {[],[],St};
pat_bit_expr({var,Ln,V}, Old, Bvt, St) -> pat_var(V, Ln, Old, Bvt, St);
pat_bit_expr({string,_,_}, _Old, _Bvt, St) -> {[],[],St};
pat_bit_expr({bin,L,_}, _Old, _Bvt, St) ->
{[],[],add_error(L, illegal_pattern, St)};
pat_bit_expr(P, _Old, _Bvt, St) ->
case is_pattern_expr(P) of
true -> {[],[],St};
false -> {[],[],add_error(element(2, P), illegal_pattern, St)}
end.
%% pat_bit_size(Size, VarTable, BinVarTable, State) ->
%% {Value,UpdVarTable,UpdBinVarTable,State}.
%% Check pattern size expression, only allow really valid sizes!
pat_bit_size(default, _Vt, _Bvt, St) -> {default,[],[],St};
pat_bit_size({atom,_Line,all}, _Vt, _Bvt, St) -> {all,[],[],St};
pat_bit_size({var,Lv,V}, Vt0, Bvt0, St0) ->
{Vt,Bvt,St1} = pat_binsize_var(V, Lv, Vt0, Bvt0, St0),
{unknown,Vt,Bvt,St1};
pat_bit_size(Size, _Vt, _Bvt, St) ->
Line = element(2, Size),
case is_pattern_expr(Size) of
true ->
case erl_eval:partial_eval(Size) of
{integer,Line,I} -> {I,[],[],St};
_Other -> {unknown,[],[],add_error(Line, illegal_bitsize, St)}
end;
false -> {unknown,[],[],add_error(Line, illegal_bitsize, St)}
end.
%% expr_bin(Line, [Element], VarTable, State, CheckFun) -> {UpdVarTable,State}.
%% Check an expression group.
expr_bin(Es, Vt, St0, Check) ->
{_Sz,Esvt,St1} = foldl(fun (E, Acc) -> bin_element(E, Vt, Acc, Check) end,
{0,[],St0}, Es),
{Esvt,St1}.
bin_element({bin_element,Line,E,Sz0,Ts}, Vt, {Size0,Esvt,St0}, Check) ->
{Vt1,St1} = Check(E, Vt, St0),
{Sz1,Vt2,St2} = bit_size(Sz0, Vt, St1, Check),
{Sz2,Bt,St3} = bit_type(Line, Sz1, Ts, St2),
{Sz3,St4} = bit_size_check(Line, Sz2, Bt, St3),
{Size1,St5} = add_bit_size(Line, Sz3, Size0, true, St4),
{Size1,vtmerge([Vt2,Vt1,Esvt]),St5}.
bit_size(default, _Vt, St, _Check) -> {default,[],St};
bit_size({atom,_Line,all}, _Vt, St, _Check) -> {all,[],St};
bit_size(Size, Vt, St, Check) ->
%% Try to safely evaluate Size if constant to get size,
%% otherwise just treat it as an expression.
case is_gexpr(Size, St#lint.records) of
true ->
case erl_eval:partial_eval(Size) of
{integer,_ILn,I} -> {I,[],St};
_Other ->
{Evt,St1} = Check(Size, Vt, St),
{unknown,Evt,St1}
end;
false ->
{Evt,St1} = Check(Size, Vt, St),
{unknown,Evt,St1}
end.
%% bit_type(Line, Size, TypeList, State) -> {Size,#bittype,St}.
%% Perform warning check on type and size.
bit_type(Line, Size0, Type, St) ->
case erl_bits:set_bit_type(Size0, Type) of
{ok,Size1,Bt} -> {Size1,Bt,St};
{error,What} ->
%% Flag error and generate a default.
{ok,Size1,Bt} = erl_bits:set_bit_type(default, []),
{Size1,Bt,add_error(Line, What, St)}
end.
%% bit_size_check(Line, Size, BitType, State) -> {BitSize,State}.
%% Do some checking & warnings on types
%% float == 32 or 64
bit_size_check(_Line, unknown, _, St) -> {unknown,St};
bit_size_check(_Line, undefined, #bittype{type=Type}, St) ->
true = (Type =:= utf8) or (Type =:= utf16) or (Type =:= utf32), %Assertion.
{undefined,St};
bit_size_check(Line, all, #bittype{type=Type}, St) ->
case Type of
binary -> {all,St};
_ -> {unknown,add_error(Line, illegal_bitsize, St)}
end;
bit_size_check(Line, Size, #bittype{type=Type,unit=Unit}, St) ->
Sz = Unit * Size, %Total number of bits!
St2 = elemtype_check(Line, Type, Sz, St),
{Sz,St2}.
elemtype_check(_Line, float, 32, St) -> St;
elemtype_check(_Line, float, 64, St) -> St;
elemtype_check(Line, float, _Size, St) ->
add_warning(Line, {bad_bitsize,"float"}, St);
elemtype_check(_Line, _Type, _Size, St) -> St.
%% add_bit_size(Line, ElementSize, BinSize, Build, State) -> {Size,State}.
%% Add bits to group size.
add_bit_size(Line, _Sz1, all, false, St) ->
{all,add_error(Line, unsized_binary_not_at_end, St)};
add_bit_size(_Line, _Sz1, all, true, St) ->
{all,St};
add_bit_size(_Line, all, _Sz2, _B, St) -> {all,St};
add_bit_size(_Line, undefined, _Sz2, _B, St) -> {undefined,St};
add_bit_size(_Line, unknown, _Sz2, _B, St) -> {unknown,St};
add_bit_size(_Line, _Sz1, undefined, _B, St) -> {unknown,St};
add_bit_size(_Line, _Sz1, unknown, _B, St) -> {unknown,St};
add_bit_size(_Line, Sz1, Sz2, _B, St) -> {Sz1 + Sz2,St}.
%% guard([GuardTest], VarTable, State) ->
%% {UsedVarTable,State}
%% Check a guard, return all variables.
%% Disjunction of guard conjunctions
guard([L|R], Vt, St0) when is_list(L) ->
{Gvt, St1} = guard_tests(L, Vt, St0),
{Gsvt, St2} = guard(R, vtupdate(Gvt, Vt), St1),
{vtupdate(Gvt, Gsvt),St2};
guard(L, Vt, St0) ->
guard_tests(L, Vt, St0).
%% guard conjunction
guard_tests([G|Gs], Vt, St0) ->
{Gvt,St1} = guard_test(G, Vt, St0),
{Gsvt,St2} = guard_tests(Gs, vtupdate(Gvt, Vt), St1),
{vtupdate(Gvt, Gsvt),St2};
guard_tests([], _Vt, St) -> {[],St}.
%% guard_test(Test, VarTable, State) ->
%% {UsedVarTable,State'}
%% Check one guard test, returns NewVariables. We now allow more
%% expressions in guards including the new is_XXX type tests, but
%% only allow the old type tests at the top level.
guard_test(G, Vt, St0) ->
St1 = obsolete_guard(G, St0),
guard_test2(G, Vt, St1).
%% Specially handle record type test here.
guard_test2({call,Line,{atom,Lr,record},[E,A]}, Vt, St0) ->
gexpr({call,Line,{atom,Lr,is_record},[E,A]}, Vt, St0);
guard_test2({call,_Line,{atom,_La,F},As}=G, Vt, St0) ->
{Asvt,St1} = gexpr_list(As, Vt, St0), %Always check this.
A = length(As),
case erl_internal:type_test(F, A) of
true when F =/= is_record -> {Asvt,St1};
_ -> gexpr(G, Vt, St0)
end;
guard_test2(G, Vt, St) ->
%% Everything else is a guard expression.
gexpr(G, Vt, St).
%% gexpr(GuardExpression, VarTable, State) ->
%% {UsedVarTable,State'}
%% Check a guard expression, returns NewVariables.
gexpr({var,Line,V}, Vt, St) ->
expr_var(V, Line, Vt, St);
gexpr({char,_Line,_C}, _Vt, St) -> {[],St};
gexpr({integer,_Line,_I}, _Vt, St) -> {[],St};
gexpr({float,_Line,_F}, _Vt, St) -> {[],St};
gexpr({atom,Line,A}, _Vt, St) ->
{[],keyword_warning(Line, A, St)};
gexpr({string,_Line,_S}, _Vt, St) -> {[],St};
gexpr({nil,_Line}, _Vt, St) -> {[],St};
gexpr({cons,_Line,H,T}, Vt, St) ->
gexpr_list([H,T], Vt, St);
gexpr({tuple,_Line,Es}, Vt, St) ->
gexpr_list(Es, Vt, St);
gexpr({record_index,Line,Name,Field}, _Vt, St) ->
check_record(Line, Name, St,
fun (Dfs, St1) -> record_field(Field, Name, Dfs, St1) end );
gexpr({record_field,Line,_,_}=M, _Vt, St0) ->
case expand_package(M, St0) of
{error, St1} ->
{[],add_error(Line, illegal_expr, St1)};
{_, St1} ->
{[], St1}
end;
gexpr({record_field,Line,Rec,Name,Field}, Vt, St0) ->
{Rvt,St1} = gexpr(Rec, Vt, St0),
{Fvt,St2} = check_record(Line, Name, St1,
fun (Dfs, St) ->
record_field(Field, Name, Dfs, St)
end),
{vtmerge(Rvt, Fvt),St2};
gexpr({record,Line,Name,Inits}, Vt, St) ->
check_record(Line, Name, St,
fun (Dfs, St1) ->
ginit_fields(Inits, Line, Name, Dfs, Vt, St1)
end);
gexpr({bin,_Line,Fs}, Vt,St) ->
expr_bin(Fs, Vt, St, fun gexpr/3);
gexpr({call,_Line,{atom,_Lr,is_record},[E,{atom,Ln,Name}]}, Vt, St0) ->
{Rvt,St1} = gexpr(E, Vt, St0),
{Rvt,exist_record(Ln, Name, St1)};
gexpr({call,Line,{atom,_Lr,is_record},[E,R]}, Vt, St0) ->
{Asvt,St1} = gexpr_list([E,R], Vt, St0),
{Asvt,add_error(Line, illegal_guard_expr, St1)};
gexpr({call,Line,{remote,_Lr,{atom,_Lm,erlang},{atom,Lf,is_record}},[E,A]},
Vt, St0) ->
gexpr({call,Line,{atom,Lf,is_record},[E,A]}, Vt, St0);
gexpr({call,_Line,{atom,_Lr,is_record},[E,{atom,_,_Name},{integer,_,_}]},
Vt, St0) ->
gexpr(E, Vt, St0);
gexpr({call,Line,{atom,_Lr,is_record},[_,_,_]=Asvt0}, Vt, St0) ->
{Asvt,St1} = gexpr_list(Asvt0, Vt, St0),
{Asvt,add_error(Line, illegal_guard_expr, St1)};
gexpr({call,Line,{remote,_,{atom,_,erlang},{atom,_,is_record}=Isr},[_,_,_]=Args},
Vt, St0) ->
gexpr({call,Line,Isr,Args}, Vt, St0);
gexpr({call,Line,{atom,_La,F},As}, Vt, St0) ->
{Asvt,St1} = gexpr_list(As, Vt, St0),
A = length(As),
%% BifClash - Function called in guard
case erl_internal:guard_bif(F, A) andalso no_guard_bif_clash(St1,{F,A}) of
true ->
%% Also check that it is auto-imported.
case erl_internal:bif(F, A) of
true -> {Asvt,St1};
false -> {Asvt,add_error(Line, {explicit_export,F,A}, St1)}
end;
false ->
{Asvt,add_error(Line, illegal_guard_expr, St1)}
end;
gexpr({call,Line,{remote,_Lr,{atom,_Lm,erlang},{atom,_Lf,F}},As}, Vt, St0) ->
{Asvt,St1} = gexpr_list(As, Vt, St0),
A = length(As),
case erl_internal:guard_bif(F, A) orelse is_gexpr_op(F, A) of
true -> {Asvt,St1};
false -> {Asvt,add_error(Line, illegal_guard_expr, St1)}
end;
gexpr({call,L,{tuple,Lt,[{atom,Lm,erlang},{atom,Lf,F}]},As}, Vt, St) ->
gexpr({call,L,{remote,Lt,{atom,Lm,erlang},{atom,Lf,F}},As}, Vt, St);
gexpr({op,Line,Op,A}, Vt, St0) ->
{Avt,St1} = gexpr(A, Vt, St0),
case is_gexpr_op(Op, 1) of
true -> {Avt,St1};
false -> {Avt,add_error(Line, illegal_guard_expr, St1)}
end;
gexpr({op,Line,Op,L,R}, Vt, St0) ->
{Avt,St1} = gexpr_list([L,R], Vt, St0),
case is_gexpr_op(Op, 2) of
true -> {Avt,St1};
false -> {Avt,add_error(Line, illegal_guard_expr, St1)}
end;
%% Everything else is illegal! You could put explicit tests here to
%% better error diagnostics.
gexpr(E, _Vt, St) ->
{[],add_error(element(2, E), illegal_guard_expr, St)}.
%% gexpr_list(Expressions, VarTable, State) ->
%% {UsedVarTable,State'}
gexpr_list(Es, Vt, St) ->
foldl(fun (E, {Esvt,St0}) ->
{Evt,St1} = gexpr(E, Vt, St0),
{vtmerge(Evt, Esvt),St1}
end, {[],St}, Es).
%% is_guard_test(Expression) -> boolean().
%% Test if a general expression is a guard test.
is_guard_test(E) ->
is_guard_test2(E, dict:new()).
%% is_guard_test(Expression, Forms) -> boolean().
is_guard_test(Expression, Forms) ->
RecordAttributes = [A || A = {attribute, _, record, _D} <- Forms],
St0 = foldl(fun(Attr0, St1) ->
Attr = zip_file_and_line(Attr0, "none"),
attribute_state(Attr, St1)
end, start(), RecordAttributes),
is_guard_test2(zip_file_and_line(Expression, "nofile"), St0#lint.records).
%% is_guard_test2(Expression, RecordDefs :: dict()) -> boolean().
is_guard_test2({call,Line,{atom,Lr,record},[E,A]}, RDs) ->
is_gexpr({call,Line,{atom,Lr,is_record},[E,A]}, RDs);
is_guard_test2({call,_Line,{atom,_La,Test},As}=Call, RDs) ->
case erl_internal:type_test(Test, length(As)) of
true -> is_gexpr_list(As, RDs);
false -> is_gexpr(Call, RDs)
end;
is_guard_test2(G, RDs) ->
%%Everything else is a guard expression.
is_gexpr(G, RDs).
%% is_guard_expr(Expression) -> boolean().
%% Test if an expression is a guard expression.
is_guard_expr(E) -> is_gexpr(E, []).
is_gexpr({var,_L,_V}, _RDs) -> true;
is_gexpr({char,_L,_C}, _RDs) -> true;
is_gexpr({integer,_L,_I}, _RDs) -> true;
is_gexpr({float,_L,_F}, _RDs) -> true;
is_gexpr({atom,_L,_A}, _RDs) -> true;
is_gexpr({string,_L,_S}, _RDs) -> true;
is_gexpr({nil,_L}, _RDs) -> true;
is_gexpr({cons,_L,H,T}, RDs) -> is_gexpr_list([H,T], RDs);
is_gexpr({tuple,_L,Es}, RDs) -> is_gexpr_list(Es, RDs);
%%is_gexpr({struct,_L,_Tag,Es}, RDs) ->
%% is_gexpr_list(Es, RDs);
is_gexpr({record_index,_L,_Name,Field}, RDs) ->
is_gexpr(Field, RDs);
is_gexpr({record_field,_L,_,_}=M, _RDs) ->
erl_parse:package_segments(M) =/= error;
is_gexpr({record_field,_L,Rec,_Name,Field}, RDs) ->
is_gexpr_list([Rec,Field], RDs);
is_gexpr({record,L,Name,Inits}, RDs) ->
is_gexpr_fields(Inits, L, Name, RDs);
is_gexpr({bin,_L,Fs}, RDs) ->
all(fun ({bin_element,_Line,E,Sz,_Ts}) ->
is_gexpr(E, RDs) and (Sz =:= default orelse is_gexpr(Sz, RDs))
end, Fs);
is_gexpr({call,_L,{atom,_Lf,F},As}, RDs) ->
A = length(As),
erl_internal:guard_bif(F, A) andalso is_gexpr_list(As, RDs);
is_gexpr({call,_L,{remote,_Lr,{atom,_Lm,erlang},{atom,_Lf,F}},As}, RDs) ->
A = length(As),
(erl_internal:guard_bif(F, A) orelse is_gexpr_op(F, A))
andalso is_gexpr_list(As, RDs);
is_gexpr({call,L,{tuple,Lt,[{atom,Lm,erlang},{atom,Lf,F}]},As}, RDs) ->
is_gexpr({call,L,{remote,Lt,{atom,Lm,erlang},{atom,Lf,F}},As}, RDs);
is_gexpr({op,_L,Op,A}, RDs) ->
is_gexpr_op(Op, 1) andalso is_gexpr(A, RDs);
is_gexpr({op,_L,Op,A1,A2}, RDs) ->
is_gexpr_op(Op, 2) andalso is_gexpr_list([A1,A2], RDs);
is_gexpr(_Other, _RDs) -> false.
is_gexpr_op('andalso', 2) -> true;
is_gexpr_op('orelse', 2) -> true;
is_gexpr_op(Op, A) ->
try erl_internal:op_type(Op, A) of
arith -> true;
bool -> true;
comp -> true;
list -> false;
send -> false
catch _:_ -> false
end.
is_gexpr_list(Es, RDs) -> all(fun (E) -> is_gexpr(E, RDs) end, Es).
is_gexpr_fields(Fs, L, Name, RDs) ->
IFs = case dict:find(Name, RDs) of
{ok,{_Line,Fields}} -> Fs ++ init_fields(Fs, L, Fields);
error -> Fs
end,
all(fun ({record_field,_Lf,_Name,V}) -> is_gexpr(V, RDs);
(_Other) -> false end, IFs).
%% exprs(Sequence, VarTable, State) ->
%% {UsedVarTable,State'}
%% Check a sequence of expressions, return all variables.
exprs([E|Es], Vt, St0) ->
{Evt,St1} = expr(E, Vt, St0),
{Esvt,St2} = exprs(Es, vtupdate(Evt, Vt), St1),
{vtupdate(Evt, Esvt),St2};
exprs([], _Vt, St) -> {[],St}.
%% expr(Expression, VarTable, State) ->
%% {UsedVarTable,State'}
%% Check an expression, returns NewVariables. Assume naive users and
%% mark illegally exported variables, e.g. from catch, as unsafe to better
%% show why unbound.
expr({var,Line,V}, Vt, St) ->
expr_var(V, Line, Vt, St);
expr({char,_Line,_C}, _Vt, St) -> {[],St};
expr({integer,_Line,_I}, _Vt, St) -> {[],St};
expr({float,_Line,_F}, _Vt, St) -> {[],St};
expr({atom,Line,A}, _Vt, St) ->
{[],keyword_warning(Line, A, St)};
expr({string,_Line,_S}, _Vt, St) -> {[],St};
expr({nil,_Line}, _Vt, St) -> {[],St};
expr({cons,_Line,H,T}, Vt, St) ->
expr_list([H,T], Vt, St);
expr({lc,_Line,E,Qs}, Vt0, St0) ->
{Vt,St} = handle_comprehension(E, Qs, Vt0, St0),
{vtold(Vt, Vt0),St}; %Don't export local variables
expr({bc,_Line,E,Qs}, Vt0, St0) ->
{Vt,St} = handle_comprehension(E, Qs, Vt0, St0),
{vtold(Vt,Vt0),St}; %Don't export local variables
expr({tuple,_Line,Es}, Vt, St) ->
expr_list(Es, Vt, St);
expr({record_index,Line,Name,Field}, _Vt, St) ->
check_record(Line, Name, St,
fun (Dfs, St1) -> record_field(Field, Name, Dfs, St1) end);
expr({record,Line,Name,Inits}, Vt, St) ->
check_record(Line, Name, St,
fun (Dfs, St1) ->
init_fields(Inits, Line, Name, Dfs, Vt, St1)
end);
expr({record_field,Line,_,_}=M, _Vt, St0) ->
case expand_package(M, St0) of
{error, St1} ->
{[],add_error(Line, illegal_expr, St1)};
{_, St1} ->
{[], St1}
end;
expr({record_field,Line,Rec,Name,Field}, Vt, St0) ->
{Rvt,St1} = record_expr(Line, Rec, Vt, St0),
{Fvt,St2} = check_record(Line, Name, St1,
fun (Dfs, St) ->
record_field(Field, Name, Dfs, St)
end),
{vtmerge(Rvt, Fvt),St2};
expr({record,Line,Rec,Name,Upds}, Vt, St0) ->
{Rvt,St1} = record_expr(Line, Rec, Vt, St0),
{Usvt,St2} = check_record(Line, Name, St1,
fun (Dfs, St) ->
update_fields(Upds, Name, Dfs, Vt, St)
end ),
case has_wildcard_field(Upds) of
true -> {[],add_error(Line, {wildcard_in_update,Name}, St2)};
false -> {vtmerge(Rvt, Usvt),St2}
end;
expr({bin,_Line,Fs}, Vt, St) ->
expr_bin(Fs, Vt, St, fun expr/3);
expr({block,_Line,Es}, Vt, St) ->
%% Unfold block into a sequence.
exprs(Es, Vt, St);
expr({'if',Line,Cs}, Vt, St) ->
icrt_clauses(Cs, {'if',Line}, Vt, St);
expr({'case',Line,E,Cs}, Vt, St0) ->
{Evt,St1} = expr(E, Vt, St0),
{Cvt,St2} = icrt_clauses(Cs, {'case',Line}, vtupdate(Evt, Vt), St1),
{vtmerge(Evt, Cvt),St2};
expr({'receive',Line,Cs}, Vt, St) ->
icrt_clauses(Cs, {'receive',Line}, Vt, St);
expr({'receive',Line,Cs,To,ToEs}, Vt, St0) ->
%% Are variables from the timeout expression visible in the clauses? NO!
{Tvt,St1} = expr(To, Vt, St0),
{Tevt,St2} = exprs(ToEs, Vt, St1),
{Cvt,St3} = icrt_clauses(Cs, Vt, St2),
%% Csvts = [vtnew(Tevt, Vt)|Cvt], %This is just NEW variables!
Csvts = [Tevt|Cvt],
{Rvt,St4} = icrt_export(Csvts, Vt, {'receive',Line}, St3),
{vtmerge([Tvt,Tevt,Rvt]),St4};
expr({'fun',Line,Body}, Vt, St) ->
%%No one can think funs export!
case Body of
{clauses,Cs} ->
{Bvt, St1} = fun_clauses(Cs, Vt, St),
{vtupdate(Bvt, Vt), St1};
{function,F,A} ->
%% BifClash - Fun expression
%% N.B. Only allows BIFs here as well, NO IMPORTS!!
case ((not is_local_function(St#lint.locals,{F,A})) andalso
(erl_internal:bif(F, A) andalso
(not is_autoimport_suppressed(St#lint.no_auto,{F,A})))) of
true -> {[],St};
false -> {[],call_function(Line, F, A, St)}
end;
{function,_M,_F,_A} ->
{[],St}
end;
expr({call,_Line,{atom,_Lr,is_record},[E,{atom,Ln,Name}]}, Vt, St0) ->
{Rvt,St1} = expr(E, Vt, St0),
{Rvt,exist_record(Ln, Name, St1)};
expr({call,Line,{remote,_Lr,{atom,_Lm,erlang},{atom,Lf,is_record}},[E,A]},
Vt, St0) ->
expr({call,Line,{atom,Lf,is_record},[E,A]}, Vt, St0);
expr({call,L,{tuple,Lt,[{atom,Lm,erlang},{atom,Lf,is_record}]},As}, Vt, St) ->
expr({call,L,{remote,Lt,{atom,Lm,erlang},{atom,Lf,is_record}},As}, Vt, St);
expr({call,Line,{remote,_Lr,M,F},As}, Vt, St0) ->
case expand_package(M, St0) of
{error, _} ->
expr_list([M,F|As], Vt, St0);
{{atom,_La,M1}, St1} ->
case F of
{atom,Lf,F1} ->
St2 = keyword_warning(Lf, F1, St1),
St3 = check_remote_function(Line, M1, F1, As, St2),
expr_list(As, Vt, St3);
_ ->
expr_list([F|As], Vt, St1)
end
end;
expr({call,Line,{atom,La,F},As}, Vt, St0) ->
St1 = keyword_warning(La, F, St0),
{Asvt,St2} = expr_list(As, Vt, St1),
A = length(As),
IsLocal = is_local_function(St2#lint.locals,{F,A}),
IsAutoBif = erl_internal:bif(F, A),
AutoSuppressed = is_autoimport_suppressed(St2#lint.no_auto,{F,A}),
Warn = is_warn_enabled(bif_clash, St2) and (not bif_clash_specifically_disabled(St2,{F,A})),
case ((not IsLocal) andalso IsAutoBif andalso (not AutoSuppressed)) of
true ->
St3 = deprecated_function(Line, erlang, F, As, St2),
{Asvt,St3};
false ->
{Asvt,case imported(F, A, St2) of
{yes,M} ->
St3 = check_remote_function(Line, M, F, As, St2),
U0 = St3#lint.usage,
Imp = ordsets:add_element({{F,A},M},U0#usage.imported),
St3#lint{usage=U0#usage{imported = Imp}};
no ->
case {F,A} of
{record_info,2} ->
check_record_info_call(Line,La,As,St2);
N ->
%% BifClash - function call
%% Issue these warnings/errors even if it's a recursive call
St3 = if
(not AutoSuppressed) andalso IsAutoBif andalso Warn ->
case erl_internal:old_bif(F,A) of
true ->
add_error
(Line,
{call_to_redefined_old_bif, {F,A}},
St2);
false ->
add_warning
(Line,
{call_to_redefined_bif, {F,A}},
St2)
end;
true ->
St2
end,
%% ...but don't lint recursive calls
if
N =:= St3#lint.func ->
St3;
true ->
call_function(Line, F, A, St3)
end
end
end}
end;
expr({call,Line,{record_field,_,_,_}=F,As}, Vt, St0) ->
case expand_package(F, St0) of
{error, _} ->
expr_list([F|As], Vt, St0);
{A, St1} ->
expr({call,Line,A,As}, Vt, St1)
end;
expr({call,Line,F,As}, Vt, St0) ->
St = warn_invalid_call(Line,F,St0),
expr_list([F|As], Vt, St); %They see the same variables
expr({'try',Line,Es,Scs,Ccs,As}, Vt, St0) ->
%% Currently, we don't allow any exports because later
%% passes cannot handle exports in combination with 'after'.
{Evt0,St1} = exprs(Es, Vt, St0),
TryLine = {'try',Line},
Uvt = vtunsafe(vtnames(vtnew(Evt0, Vt)), TryLine, []),
Evt1 = vtupdate(Uvt, vtupdate(Evt0, Vt)),
{Sccs,St2} = icrt_clauses(Scs++Ccs, TryLine, Evt1, St1),
Rvt0 = Sccs,
Rvt1 = vtupdate(vtunsafe(vtnames(vtnew(Rvt0, Vt)), TryLine, []), Rvt0),
Evt2 = vtmerge(Evt1, Rvt1),
{Avt0,St} = exprs(As, Evt2, St2),
Avt1 = vtupdate(vtunsafe(vtnames(vtnew(Avt0, Vt)), TryLine, []), Avt0),
Avt = vtmerge(Evt2, Avt1),
{Avt,St};
expr({'catch',Line,E}, Vt, St0) ->
%% No new variables added, flag new variables as unsafe.
{Evt,St1} = expr(E, Vt, St0),
Uvt = vtunsafe(vtnames(vtnew(Evt, Vt)), {'catch',Line}, []),
{vtupdate(Uvt,vtupdate(Evt, Vt)),St1};
expr({match,_Line,P,E}, Vt, St0) ->
{Evt,St1} = expr(E, Vt, St0),
{Pvt,Bvt,St2} = pattern(P, vtupdate(Evt, Vt), St1),
St = reject_bin_alias_expr(P, E, St2),
{vtupdate(Bvt, vtmerge(Evt, Pvt)),St};
%% No comparison or boolean operators yet.
expr({op,_Line,_Op,A}, Vt, St) ->
expr(A, Vt, St);
expr({op,Line,Op,L,R}, Vt, St0) when Op =:= 'orelse'; Op =:= 'andalso' ->
{Evt1,St1} = expr(L, Vt, St0),
Vt1 = vtupdate(Evt1, Vt),
{Evt2,St2} = expr(R, Vt1, St1),
Vt2 = vtmerge(Evt2, Vt1),
{Vt3,St3} = icrt_export([Vt1,Vt2], Vt1, {Op,Line}, St2),
{vtmerge(Evt1, Vt3),St3};
expr({op,_Line,_Op,L,R}, Vt, St) ->
expr_list([L,R], Vt, St); %They see the same variables
%% The following are not allowed to occur anywhere!
expr({remote,Line,_M,_F}, _Vt, St) ->
{[],add_error(Line, illegal_expr, St)};
expr({'query',Line,_Q}, _Vt, St) ->
{[],add_error(Line, {mnemosyne,"query"}, St)}.
%% expr_list(Expressions, Variables, State) ->
%% {UsedVarTable,State}
expr_list(Es, Vt, St) ->
foldl(fun (E, {Esvt,St0}) ->
{Evt,St1} = expr(E, Vt, St0),
{vtmerge(Evt, Esvt),St1}
end, {[],St}, Es).
record_expr(Line, Rec, Vt, St0) ->
St1 = warn_invalid_record(Line, Rec, St0),
expr(Rec, Vt, St1).
%% warn_invalid_record(Line, Record, State0) -> State
%% Adds warning if the record is invalid.
warn_invalid_record(Line, R, St) ->
case is_valid_record(R) of
true -> St;
false -> add_warning(Line, invalid_record, St)
end.
%% is_valid_record(Record) -> boolean().
is_valid_record(Rec) ->
case Rec of
{char, _, _} -> false;
{integer, _, _} -> false;
{float, _, _} -> false;
{atom, _, _} -> false;
{string, _, _} -> false;
{cons, _, _, _} -> false;
{nil, _} -> false;
{lc, _, _, _} -> false;
{record_index, _, _, _} -> false;
{'fun', _, _} -> false;
_ -> true
end.
%% warn_invalid_call(Line, Call, State0) -> State
%% Adds warning if the call is invalid.
warn_invalid_call(Line, F, St) ->
case is_valid_call(F) of
true -> St;
false -> add_warning(Line, invalid_call, St)
end.
%% is_valid_call(Call) -> boolean().
is_valid_call(Call) ->
case Call of
{char, _, _} -> false;
{integer, _, _} -> false;
{float, _, _} -> false;
{string, _, _} -> false;
{cons, _, _, _} -> false;
{nil, _} -> false;
{lc, _, _, _} -> false;
{record_index, _, _, _} -> false;
{tuple, _, Exprs} when length(Exprs) =/= 2 -> false;
_ -> true
end.
%% record_def(Line, RecordName, [RecField], State) -> State.
%% Add a record definition if it does not already exist. Normalise
%% so that all fields have explicit initial value.
record_def(Line, Name, Fs0, St0) ->
case dict:is_key(Name, St0#lint.records) of
true -> add_error(Line, {redefine_record,Name}, St0);
false ->
{Fs1,St1} = def_fields(normalise_fields(Fs0), Name, St0),
St1#lint{records=dict:store(Name, {Line,Fs1}, St1#lint.records)}
end.
%% def_fields([RecDef], RecordName, State) -> {[DefField],State}.
%% Check (normalised) fields for duplicates. Return unduplicated
%% record and set State.
def_fields(Fs0, Name, St0) ->
foldl(fun ({record_field,Lf,{atom,La,F},V}, {Fs,St}) ->
case exist_field(F, Fs) of
true -> {Fs,add_error(Lf, {redefine_field,Name,F}, St)};
false ->
St1 = St#lint{recdef_top = true},
{_,St2} = expr(V, [], St1),
%% Warnings and errors found are kept, but
%% updated calls, records, etc. are discarded.
St3 = St1#lint{warnings = St2#lint.warnings,
errors = St2#lint.errors,
called = St2#lint.called,
recdef_top = false},
%% This is one way of avoiding a loop for
%% "recursive" definitions.
NV = case St2#lint.errors =:= St1#lint.errors of
true -> V;
false -> {atom,La,undefined}
end,
{[{record_field,Lf,{atom,La,F},NV}|Fs],St3}
end
end, {[],St0}, Fs0).
%% normalise_fields([RecDef]) -> [Field].
%% Normalise the field definitions to always have a default value. If
%% none has been given then use 'undefined'.
%% Also, strip type information from typed record fields.
normalise_fields(Fs) ->
map(fun ({record_field,Lf,Field}) ->
{record_field,Lf,Field,{atom,Lf,undefined}};
({typed_record_field,{record_field,Lf,Field},_Type}) ->
{record_field,Lf,Field,{atom,Lf,undefined}};
({typed_record_field,Field,_Type}) ->
Field;
(F) -> F end, Fs).
%% exist_record(Line, RecordName, State) -> State.
%% Check if a record exists. Set State.
exist_record(Line, Name, St) ->
case dict:is_key(Name, St#lint.records) of
true -> used_record(Name, St);
false -> add_error(Line, {undefined_record,Name}, St)
end.
%% check_record(Line, RecordName, State, CheckFun) ->
%% {UpdVarTable, State}.
%% The generic record checking function, first checks that the record
%% exists then calls the specific check function. N.B. the check
%% function can safely assume that the record exists.
%%
%% The check function is called:
%% CheckFun(RecordDefFields, State)
%% and must return
%% {UpdatedVarTable,State}
check_record(Line, Name, St, CheckFun) ->
case dict:find(Name, St#lint.records) of
{ok,{_Line,Fields}} -> CheckFun(Fields, used_record(Name, St));
error -> {[],add_error(Line, {undefined_record,Name}, St)}
end.
used_record(Name, #lint{usage=Usage}=St) ->
UsedRecs = sets:add_element(Name, Usage#usage.used_records),
St#lint{usage = Usage#usage{used_records=UsedRecs}}.
%%% Record check functions.
%% check_fields([ChkField], RecordName, [RecDefField], VarTable, State, CheckFun) ->
%% {UpdVarTable,State}.
check_fields(Fs, Name, Fields, Vt, St0, CheckFun) ->
{_SeenFields,Uvt,St1} =
foldl(fun (Field, {Sfsa,Vta,Sta}) ->
{Sfsb,{Vtb,Stb}} = check_field(Field, Name, Fields,
Vt, Sta, Sfsa, CheckFun),
{Sfsb,vtmerge_pat(Vta, Vtb),Stb}
end, {[],[],St0}, Fs),
{Uvt,St1}.
check_field({record_field,Lf,{atom,La,F},Val}, Name, Fields,
Vt, St, Sfs, CheckFun) ->
case member(F, Sfs) of
true -> {Sfs,{Vt,add_error(Lf, {redefine_field,Name,F}, St)}};
false ->
{[F|Sfs],
case find_field(F, Fields) of
{ok,_I} -> CheckFun(Val, Vt, St);
error -> {[],add_error(La, {undefined_field,Name,F}, St)}
end}
end;
check_field({record_field,_Lf,{var,_La,'_'},Val}, _Name, _Fields,
Vt, St, Sfs, CheckFun) ->
{Sfs,CheckFun(Val, Vt, St)};
check_field({record_field,_Lf,{var,La,V},_Val}, Name, _Fields,
Vt, St, Sfs, _CheckFun) ->
{Sfs,{Vt,add_error(La, {field_name_is_variable,Name,V}, St)}}.
%% pattern_field(Field, RecordName, [RecDefField], State) ->
%% {UpdVarTable,State}.
%% Test if record RecordName has field Field. Set State.
pattern_field({atom,La,F}, Name, Fields, St) ->
case find_field(F, Fields) of
{ok,_I} -> {[],St};
error -> {[],add_error(La, {undefined_field,Name,F}, St)}
end.
%% pattern_fields([PatField],RecordName,[RecDefField],
%% VarTable,Old,Bvt,State) ->
%% {UpdVarTable,UpdBinVarTable,State}.
pattern_fields(Fs, Name, Fields, Vt0, Old, Bvt, St0) ->
CheckFun = fun (Val, Vt, St) -> pattern(Val, Vt, Old, Bvt, St) end,
{_SeenFields,Uvt,Bvt1,St1} =
foldl(fun (Field, {Sfsa,Vta,Bvt1,Sta}) ->
case check_field(Field, Name, Fields,
Vt0, Sta, Sfsa, CheckFun) of
{Sfsb,{Vtb,Stb}} ->
{Sfsb,vtmerge_pat(Vta, Vtb),[],Stb};
{Sfsb,{Vtb,Bvt2,Stb}} ->
{Sfsb,vtmerge_pat(Vta, Vtb),
vtmerge_pat(Bvt1,Bvt2),Stb}
end
end, {[],[],[],St0}, Fs),
{Uvt,Bvt1,St1}.
%% record_field(Field, RecordName, [RecDefField], State) ->
%% {UpdVarTable,State}.
%% Test if record RecordName has field Field. Set State.
record_field({atom,La,F}, Name, Fields, St) ->
case find_field(F, Fields) of
{ok,_I} -> {[],St};
error -> {[],add_error(La, {undefined_field,Name,F}, St)}
end.
%% init_fields([InitField], InitLine, RecordName, [DefField], VarTable, State) ->
%% {UpdVarTable,State}.
%% ginit_fields([InitField], InitLine, RecordName, [DefField], VarTable, State) ->
%% {UpdVarTable,State}.
%% Check record initialisation. Explicit initialisations are checked
%% as is, while default values are checked only if there are no
%% explicit inititialisations of the fields. Be careful not to
%% duplicate warnings (and possibly errors, but def_fields
%% substitutes 'undefined' for bogus inititialisations) from when the
%% record definitions were checked. Usage of records, imports, and
%% functions is collected.
init_fields(Ifs, Line, Name, Dfs, Vt0, St0) ->
{Vt1,St1} = check_fields(Ifs, Name, Dfs, Vt0, St0, fun expr/3),
Defs = init_fields(Ifs, Line, Dfs),
{_,St2} = check_fields(Defs, Name, Dfs, Vt1, St1, fun expr/3),
{Vt1,St1#lint{usage = St2#lint.usage}}.
ginit_fields(Ifs, Line, Name, Dfs, Vt0, St0) ->
{Vt1,St1} = check_fields(Ifs, Name, Dfs, Vt0, St0, fun gexpr/3),
Defs = init_fields(Ifs, Line, Dfs),
St2 = St1#lint{errors = []},
{_,St3} = check_fields(Defs, Name, Dfs, Vt1, St2, fun gexpr/3),
#lint{usage = Usage, errors = Errors} = St3,
IllErrs = [E || {_File,{_Line,erl_lint,illegal_guard_expr}}=E <- Errors],
St4 = St1#lint{usage = Usage, errors = IllErrs ++ St1#lint.errors},
{Vt1,St4}.
%% Default initializations to be carried out
init_fields(Ifs, Line, Dfs) ->
[ {record_field,Lf,{atom,La,F},copy_expr(Di, Line)} ||
{record_field,Lf,{atom,La,F},Di} <- Dfs,
not exist_field(F, Ifs) ].
%% update_fields(UpdFields, RecordName, RecDefFields, VarTable, State) ->
%% {UpdVarTable,State}
update_fields(Ufs, Name, Dfs, Vt, St) ->
check_fields(Ufs, Name, Dfs, Vt, St, fun expr/3).
%% exist_field(FieldName, [Field]) -> boolean().
%% Find a record field in a field list.
exist_field(F, [{record_field,_Lf,{atom,_La,F},_Val}|_Fs]) -> true;
exist_field(F, [_|Fs]) -> exist_field(F, Fs);
exist_field(_F, []) -> false.
%% find_field(FieldName, [Field]) -> {ok,Val} | error.
%% Find a record field in a field list.
find_field(_F, [{record_field,_Lf,{atom,_La,_F},Val}|_Fs]) -> {ok,Val};
find_field(F, [_|Fs]) -> find_field(F, Fs);
find_field(_F, []) -> error.
%% type_def(Attr, Line, TypeName, PatField, Args, State) -> State.
%% Attr :: 'type' | 'opaque'
%% Checks that a type definition is valid.
type_def(_Attr, _Line, {record, _RecName}, Fields, [], St0) ->
%% The record field names and such are checked in the record format.
%% We only need to check the types.
Types = [T || {typed_record_field, _, T} <- Fields],
check_type({type, -1, product, Types}, St0);
type_def(_Attr, Line, TypeName, ProtoType, Args, St0) ->
TypeDefs = St0#lint.types,
Arity = length(Args),
TypePair = {TypeName, Arity},
case (dict:is_key(TypePair, TypeDefs) orelse is_var_arity_type(TypeName)) of
true ->
case dict:is_key(TypePair, default_types()) of
true ->
case is_newly_introduced_builtin_type(TypePair) of
%% allow some types just for bootstrapping
true ->
Warn = {new_builtin_type, TypePair},
St1 = add_warning(Line, Warn, St0),
NewDefs = dict:store(TypePair, Line, TypeDefs),
CheckType = {type, -1, product, [ProtoType|Args]},
check_type(CheckType, St1#lint{types=NewDefs});
false ->
add_error(Line, {builtin_type, TypePair}, St0)
end;
false -> add_error(Line, {redefine_type, TypePair}, St0)
end;
false ->
NewDefs = dict:store(TypePair, Line, TypeDefs),
CheckType = {type, -1, product, [ProtoType|Args]},
check_type(CheckType, St0#lint{types=NewDefs})
end.
check_type(Types, St) ->
{SeenVars, St1} = check_type(Types, dict:new(), St),
dict:fold(fun(Var, {seen_once, Line}, AccSt) ->
case atom_to_list(Var) of
"_"++_ -> AccSt;
_ -> add_error(Line, {singleton_typevar, Var}, AccSt)
end;
(_Var, seen_multiple, AccSt) ->
AccSt
end, St1, SeenVars).
check_type({ann_type, _L, [_Var, Type]}, SeenVars, St) ->
check_type(Type, SeenVars, St);
check_type({paren_type, _L, [Type]}, SeenVars, St) ->
check_type(Type, SeenVars, St);
check_type({remote_type, L, [{atom, _, Mod}, {atom, _, Name}, Args]},
SeenVars, #lint{module=CurrentMod} = St) ->
St1 =
case (dict:is_key({Name, length(Args)}, default_types())
orelse is_var_arity_type(Name)) of
true -> add_error(L, {imported_predefined_type, Name}, St);
false -> St
end,
case Mod =:= CurrentMod of
true -> check_type({type, L, Name, Args}, SeenVars, St1);
false ->
lists:foldl(fun(T, {AccSeenVars, AccSt}) ->
check_type(T, AccSeenVars, AccSt)
end, {SeenVars, St1}, Args)
end;
check_type({integer, _L, _}, SeenVars, St) -> {SeenVars, St};
check_type({atom, _L, _}, SeenVars, St) -> {SeenVars, St};
check_type({var, _L, '_'}, SeenVars, St) -> {SeenVars, St};
check_type({var, L, Name}, SeenVars, St) ->
NewSeenVars =
case dict:find(Name, SeenVars) of
{ok, {seen_once, _}} -> dict:store(Name, seen_multiple, SeenVars);
{ok, seen_multiple} -> SeenVars;
error -> dict:store(Name, {seen_once, L}, SeenVars)
end,
{NewSeenVars, St};
check_type({type, L, bool, []}, SeenVars, St) ->
{SeenVars, add_warning(L, {renamed_type, bool, boolean}, St)};
check_type({type, L, 'fun', [Dom, Range]}, SeenVars, St) ->
St1 =
case Dom of
{type, _, product, _} -> St;
{type, _, any} -> St;
_ -> add_error(L, {type_syntax, 'fun'}, St)
end,
check_type({type, -1, product, [Dom, Range]}, SeenVars, St1);
check_type({type, L, range, [From, To]}, SeenVars, St) ->
St1 =
case {erl_eval:partial_eval(From), erl_eval:partial_eval(To)} of
{{integer, _, X}, {integer, _, Y}} when X < Y -> St;
_ -> add_error(L, {type_syntax, range}, St)
end,
{SeenVars, St1};
check_type({type, _L, tuple, any}, SeenVars, St) -> {SeenVars, St};
check_type({type, _L, any}, SeenVars, St) -> {SeenVars, St};
check_type({type, L, binary, [Base, Unit]}, SeenVars, St) ->
St1 =
case {erl_eval:partial_eval(Base), erl_eval:partial_eval(Unit)} of
{{integer, _, BaseVal},
{integer, _, UnitVal}} when BaseVal >= 0, UnitVal >= 0 -> St;
_ -> add_error(L, {type_syntax, binary}, St)
end,
{SeenVars, St1};
check_type({type, L, record, [Name|Fields]}, SeenVars, St) ->
case Name of
{atom, _, Atom} ->
St1 = used_record(Atom, St),
check_record_types(L, Atom, Fields, SeenVars, St1);
_ -> {SeenVars, add_error(L, {type_syntax, record}, St)}
end;
check_type({type, _L, product, Args}, SeenVars, St) ->
lists:foldl(fun(T, {AccSeenVars, AccSt}) ->
check_type(T, AccSeenVars, AccSt)
end, {SeenVars, St}, Args);
check_type({type, La, TypeName, Args}, SeenVars, #lint{usage=Usage} = St) ->
Arity = length(Args),
St1 = case is_var_arity_type(TypeName) of
true -> St;
false ->
OldUsed = Usage#usage.used_types,
UsedTypes = dict:store({TypeName, Arity}, La, OldUsed),
St#lint{usage=Usage#usage{used_types=UsedTypes}}
end,
check_type({type, -1, product, Args}, SeenVars, St1);
check_type(I, SeenVars, St) ->
case erl_eval:partial_eval(I) of
{integer,_ILn,_Integer} -> {SeenVars, St};
_Other ->
{SeenVars, add_error(element(2, I), {type_syntax, integer}, St)}
end.
check_record_types(Line, Name, Fields, SeenVars, St) ->
case dict:find(Name, St#lint.records) of
{ok,{_L,DefFields}} ->
case lists:all(fun({type, _, field_type, _}) -> true;
(_) -> false
end, Fields) of
true ->
check_record_types(Fields, Name, DefFields, SeenVars, St, []);
false ->
{SeenVars, add_error(Line, {type_syntax, record}, St)}
end;
error ->
{SeenVars, add_error(Line, {undefined_record, Name}, St)}
end.
check_record_types([{type, _, field_type, [{atom, AL, FName}, Type]}|Left],
Name, DefFields, SeenVars, St, SeenFields) ->
%% Check that the field name is valid
St1 = case exist_field(FName, DefFields) of
true -> St;
false -> add_error(AL, {undefined_field, Name, FName}, St)
end,
%% Check for duplicates
St2 = case ordsets:is_element(FName, SeenFields) of
true -> add_error(AL, {redefine_field, Name, FName}, St1);
false -> St1
end,
%% Check Type
{NewSeenVars, St3} = check_type(Type, SeenVars, St2),
NewSeenFields = ordsets:add_element(FName, SeenFields),
check_record_types(Left, Name, DefFields, NewSeenVars, St3, NewSeenFields);
check_record_types([], _Name, _DefFields, SeenVars, St, _SeenFields) ->
{SeenVars, St}.
is_var_arity_type(tuple) -> true;
is_var_arity_type(product) -> true;
is_var_arity_type(union) -> true;
is_var_arity_type(record) -> true;
is_var_arity_type(_) -> false.
default_types() ->
DefTypes = [{any, 0},
{arity, 0},
{array, 0},
{atom, 0},
{atom, 1},
{binary, 0},
{binary, 2},
{bitstring, 0},
{bool, 0},
{boolean, 0},
{byte, 0},
{char, 0},
{dict, 0},
{digraph, 0},
{float, 0},
{'fun', 0},
{'fun', 2},
{function, 0},
{gb_set, 0},
{gb_tree, 0},
{identifier, 0},
{integer, 0},
{integer, 1},
{iodata, 0},
{iolist, 0},
{list, 0},
{list, 1},
{maybe_improper_list, 0},
{maybe_improper_list, 2},
{mfa, 0},
{module, 0},
{neg_integer, 0},
{nil, 0},
{no_return, 0},
{node, 0},
{non_neg_integer, 0},
{none, 0},
{nonempty_list, 0},
{nonempty_list, 1},
{nonempty_improper_list, 2},
{nonempty_maybe_improper_list, 0},
{nonempty_maybe_improper_list, 2},
{nonempty_string, 0},
{number, 0},
{pid, 0},
{port, 0},
{pos_integer, 0},
{queue, 0},
{range, 2},
{reference, 0},
{set, 0},
{string, 0},
{term, 0},
{tid, 0},
{timeout, 0},
{var, 1}],
dict:from_list([{T, -1} || T <- DefTypes]).
%% R12B-5
is_newly_introduced_builtin_type({module, 0}) -> true;
is_newly_introduced_builtin_type({node, 0}) -> true;
is_newly_introduced_builtin_type({nonempty_string, 0}) -> true;
is_newly_introduced_builtin_type({term, 0}) -> true;
is_newly_introduced_builtin_type({timeout, 0}) -> true;
%% R13
is_newly_introduced_builtin_type({arity, 0}) -> true;
is_newly_introduced_builtin_type({array, 0}) -> true; % opaque
is_newly_introduced_builtin_type({bitstring, 0}) -> true;
is_newly_introduced_builtin_type({dict, 0}) -> true; % opaque
is_newly_introduced_builtin_type({digraph, 0}) -> true; % opaque
is_newly_introduced_builtin_type({gb_set, 0}) -> true; % opaque
is_newly_introduced_builtin_type({gb_tree, 0}) -> true; % opaque
is_newly_introduced_builtin_type({iodata, 0}) -> true;
is_newly_introduced_builtin_type({queue, 0}) -> true; % opaque
is_newly_introduced_builtin_type({set, 0}) -> true; % opaque
is_newly_introduced_builtin_type({tid, 0}) -> true; % opaque
%% R13B01
is_newly_introduced_builtin_type({boolean, 0}) -> true;
is_newly_introduced_builtin_type({Name, _}) when is_atom(Name) -> false.
%% spec_decl(Line, Fun, Types, State) -> State.
spec_decl(Line, MFA0, TypeSpecs, St0 = #lint{specs = Specs, module = Mod}) ->
MFA = case MFA0 of
{F, Arity} -> {Mod, F, Arity};
{_M, _F, Arity} -> MFA0
end,
St1 = St0#lint{specs = dict:store(MFA, Line, Specs)},
case dict:is_key(MFA, Specs) of
true -> add_error(Line, {redefine_spec, MFA}, St1);
false -> check_specs(TypeSpecs, Arity, St1)
end.
check_specs([FunType|Left], Arity, St0) ->
{FunType1, CTypes} =
case FunType of
{type, _, bounded_fun, [FT = {type, _, 'fun', _}, Cs]} ->
Types0 = [T || {type, _, constraint, [_, T]} <- Cs],
{FT, lists:append(Types0)};
{type, _, 'fun', _} = FT -> {FT, []}
end,
SpecArity =
case FunType1 of
{type, L, 'fun', [any, _]} -> any;
{type, L, 'fun', [{type, _, product, D}, _]} -> length(D)
end,
St1 = case Arity =:= SpecArity of
true -> St0;
false -> add_error(L, spec_wrong_arity, St0)
end,
St2 = check_type({type, -1, product, [FunType1|CTypes]}, St1),
check_specs(Left, Arity, St2);
check_specs([], _Arity, St) ->
St.
check_specs_without_function(#lint{module=Mod,defined=Funcs,specs=Specs}=St) ->
Fun = fun({M, F, A} = MFA, Line, AccSt) when M =:= Mod ->
case gb_sets:is_element({F, A}, Funcs) of
true -> AccSt;
false -> add_error(Line, {spec_fun_undefined, MFA}, AccSt)
end;
({_M, _F, _A}, _Line, AccSt) -> AccSt
end,
dict:fold(Fun, St, Specs).
%% This generates warnings for functions without specs; if the user has
%% specified both options, we do not generate the same warnings twice.
check_functions_without_spec(Forms, St0) ->
case is_warn_enabled(missing_spec_all, St0) of
true ->
add_missing_spec_warnings(Forms, St0, all);
false ->
case is_warn_enabled(missing_spec, St0) of
true ->
add_missing_spec_warnings(Forms, St0, exported);
false ->
St0
end
end.
add_missing_spec_warnings(Forms, St0, Type) ->
Specs = [{F,A} || {_M,F,A} <- dict:fetch_keys(St0#lint.specs)],
Warns = %% functions + line numbers for which we should warn
case Type of
all ->
[{FA,L} || {function,L,F,A,_} <- Forms,
not lists:member(FA = {F,A}, Specs)];
exported ->
Exps = gb_sets:to_list(St0#lint.exports) -- pseudolocals(),
[{FA,L} || {function,L,F,A,_} <- Forms,
member(FA = {F,A}, Exps -- Specs)]
end,
foldl(fun ({FA,L}, St) ->
add_warning(L, {missing_spec,FA}, St)
end, St0, Warns).
check_unused_types(Forms, #lint{usage=Usage, types=Ts, exp_types=ExpTs}=St) ->
case [File || {attribute,_L,file,{File,_Line}} <- Forms] of
[FirstFile|_] ->
D = Usage#usage.used_types,
L = gb_sets:to_list(ExpTs) ++ dict:fetch_keys(D),
UsedTypes = gb_sets:from_list(L),
FoldFun =
fun(_Type, -1, AccSt) ->
%% Default type
AccSt;
(Type, FileLine, AccSt) ->
case loc(FileLine) of
{FirstFile, _} ->
case gb_sets:is_member(Type, UsedTypes) of
true -> AccSt;
false ->
Warn = {unused_type,Type},
add_warning(FileLine, Warn, AccSt)
end;
_ ->
%% No warns about unused types in include files
AccSt
end
end,
dict:fold(FoldFun, St, Ts);
[] ->
St
end.
%% icrt_clauses(Clauses, In, ImportVarTable, State) ->
%% {NewVts,State}.
icrt_clauses(Cs, In, Vt, St0) ->
{Csvt,St1} = icrt_clauses(Cs, Vt, St0),
icrt_export(Csvt, Vt, In, St1).
%% icrt_clauses(Clauses, ImportVarTable, State) ->
%% {NewVts,State}.
icrt_clauses(Cs, Vt, St) ->
mapfoldl(fun (C, St0) -> icrt_clause(C, Vt, St0) end, St, Cs).
icrt_clause({clause,_Line,H,G,B}, Vt0, St0) ->
{Hvt,Binvt,St1} = head(H, Vt0, St0),
Vt1 = vtupdate(Hvt, vtupdate(Binvt, Vt0)),
{Gvt,St2} = guard(G, Vt1, St1),
Vt2 = vtupdate(Gvt, Vt1),
{Bvt,St3} = exprs(B, Vt2, St2),
{vtupdate(Bvt, Vt2),St3}.
icrt_export(Csvt, Vt, In, St) ->
Vt1 = vtmerge(Csvt),
All = ordsets:subtract(vintersection(Csvt), vtnames(Vt)),
Some = ordsets:subtract(vtnames(Vt1), vtnames(Vt)),
Xvt = vtexport(All, In, []),
Evt = vtunsafe(ordsets:subtract(Some, All), In, Xvt),
Unused = vtmerge([unused_vars(Vt0, Vt, St) || Vt0 <- Csvt]),
%% Exported and unsafe variables may be unused:
Uvt = vtmerge(Evt, Unused),
%% Make exported and unsafe unused variables unused in subsequent code:
Vt2 = vtmerge(Uvt, vtsubtract(Vt1, Uvt)),
{Vt2,St}.
handle_comprehension(E, Qs, Vt0, St0) ->
{Vt1, Uvt, St1} = lc_quals(Qs, Vt0, St0),
{Evt,St2} = expr(E, Vt1, St1),
Vt2 = vtupdate(Evt, Vt1),
%% Shadowed global variables.
{_,St3} = check_old_unused_vars(Vt2, Uvt, St2),
%% There may be local variables in Uvt that are not global.
{_,St4} = check_unused_vars(Uvt, Vt0, St3),
%% Local variables that have not been shadowed.
{_,St} = check_unused_vars(Vt2, Vt0, St4),
Vt3 = vtmerge(vtsubtract(Vt2, Uvt), Uvt),
{Vt3,St}.
%% lc_quals(Qualifiers, ImportVarTable, State) ->
%% {VarTable,ShadowedVarTable,State}
%% Test list comprehension qualifiers, return all variables. Allow
%% filters to be both guard tests and general expressions, but the errors
%% will be for expressions. Return the complete updated vartable including
%% local variables and all updates. ShadowVarTable contains the state of
%% each shadowed variable. All variable states of variables in ImportVarTable
%% that have been shadowed are included in ShadowVarTable. In addition, all
%% shadowed variables that are not included in ImportVarTable are included
%% in ShadowVarTable (these are local variables that are not global variables).
lc_quals(Qs, Vt0, St0) ->
OldRecDef = St0#lint.recdef_top,
{Vt,Uvt,St} = lc_quals(Qs, Vt0, [], St0#lint{recdef_top = false}),
{Vt,Uvt,St#lint{recdef_top = OldRecDef}}.
lc_quals([{generate,_Line,P,E} | Qs], Vt0, Uvt0, St0) ->
{Vt,Uvt,St} = handle_generator(P,E,Vt0,Uvt0,St0),
lc_quals(Qs, Vt, Uvt, St);
lc_quals([{b_generate,_Line,P,E} | Qs], Vt0, Uvt0, St0) ->
{Vt,Uvt,St} = handle_generator(P,E,Vt0,Uvt0,St0),
lc_quals(Qs, Vt, Uvt, St);
lc_quals([F|Qs], Vt, Uvt, St0) ->
{Fvt,St1} = case is_guard_test2(F, St0#lint.records) of
true -> guard_test(F, Vt, St0);
false -> expr(F, Vt, St0)
end,
lc_quals(Qs, vtupdate(Fvt, Vt), Uvt, St1);
lc_quals([], Vt, Uvt, St) ->
{Vt, Uvt, St}.
handle_generator(P,E,Vt,Uvt,St0) ->
{Evt,St1} = expr(E, Vt, St0),
%% Forget variables local to E immediately.
Vt1 = vtupdate(vtold(Evt, Vt), Vt),
{_, St2} = check_unused_vars(Evt, Vt, St1),
{Pvt,Binvt,St3} = pattern(P, Vt1, [], [], St2),
%% Have to keep fresh variables separated from used variables somehow
%% in order to handle for example X = foo(), [X || <<X:X>> <- bar()].
%% 1 2 2 1
Vt2 = vtupdate(Pvt, Vt1),
St4 = shadow_vars(Binvt, Vt1, generate, St3),
Svt = vtold(Vt2, Binvt),
{_, St5} = check_old_unused_vars(Svt, Uvt, St4),
NUvt = vtupdate(vtnew(Svt, Uvt), Uvt),
Vt3 = vtupdate(vtsubtract(Vt2, Binvt), Binvt),
{Vt3,NUvt,St5}.
%% fun_clauses(Clauses, ImportVarTable, State) ->
%% {UsedVars, State}.
%% Fun's cannot export any variables.
%% It is an error if variable is bound inside a record definition
%% unless it was introduced in a fun or an lc. Only if pat_var finds
%% such variables can the correct line number be given.
fun_clauses(Cs, Vt, St) ->
OldRecDef = St#lint.recdef_top,
{Bvt,St2} = foldl(fun (C, {Bvt0, St0}) ->
{Cvt,St1} = fun_clause(C, Vt, St0),
{vtmerge(Cvt, Bvt0),St1}
end, {[],St#lint{recdef_top = false}}, Cs),
{Bvt,St2#lint{recdef_top = OldRecDef}}.
fun_clause({clause,_Line,H,G,B}, Vt0, St0) ->
{Hvt,Binvt,St1} = head(H, Vt0, [], St0), % No imported pattern variables
Vt1 = vtupdate(Hvt, Vt0),
St2 = shadow_vars(Binvt, Vt0, 'fun', St1),
Vt2 = vtupdate(vtsubtract(Vt1, Binvt), Binvt),
{Gvt,St3} = guard(G, Vt2, St2),
Vt3 = vtupdate(Gvt, Vt2),
{Bvt,St4} = exprs(B, Vt3, St3),
Cvt = vtupdate(Bvt, Vt3),
%% Check new local variables.
{_, St5} = check_unused_vars(Cvt, Vt0, St4),
%% Check all shadowing variables.
Svt = vtold(Vt1, Binvt),
{_, St6} = check_old_unused_vars(Cvt, Svt, St5),
Vt4 = vtmerge(Svt, vtsubtract(Cvt, Svt)),
{vtold(Vt4, Vt0),St6}.
%% In the variable table we store information about variables. The
%% information is a tuple {State,Usage,Lines}, the variables state and
%% usage. A variable can be in the following states:
%%
%% bound everything is normal
%% {export,From} variable has been exported
%% {unsafe,In} variable is unsafe
%%
%% The usage information has the following form:
%%
%% used variable has been used
%% unused variable has been bound but not used
%%
%% Lines is a list of line numbers where the variable was bound.
%%
%% Report variable errors/warnings as soon as possible and then change
%% the state to ok. This simplifies the code and reports errors only
%% once. Having the usage information like this makes it easy too when
%% merging states.
%% For keeping track of which variables are bound, ordsets are used.
%% In order to be able to give warnings about unused variables, a
%% possible value is {bound, unused, [Line]}. The usual value when a
%% variable is used is {bound, used, [Line]}. An exception occurs for
%% variables in the size position in a bin element in a pattern.
%% Currently, such a variable is never matched out, always used, and
%% therefore it makes no sense to warn for "variable imported in
%% match".
%% For storing the variable table we use the orddict module.
%% We know an empty set is [].
%% pat_var(Variable, LineNo, VarTable, State) -> {UpdVarTable,State}
%% A pattern variable has been found. Handle errors and warnings. Return
%% all variables as bound so errors and warnings are only reported once.
%% Bvt "shadows" Vt here, which is necessary in order to separate uses of
%% shadowed and shadowing variables. See also pat_binsize_var.
pat_var(V, Line, Vt, Bvt, St) ->
case orddict:find(V, Bvt) of
{ok, {bound,_Usage,Ls}} ->
{[],[{V,{bound,used,Ls}}],St};
error ->
case orddict:find(V, Vt) of
{ok,{bound,_Usage,Ls}} ->
{[{V,{bound,used,Ls}}],[],St};
{ok,{{unsafe,In},_Usage,Ls}} ->
{[{V,{bound,used,Ls}}],[],
add_error(Line, {unsafe_var,V,In}, St)};
{ok,{{export,From},_Usage,Ls}} ->
{[{V,{bound,used,Ls}}],[],
%% As this is matching, exported vars are risky.
add_warning(Line, {exported_var,V,From}, St)};
error when St#lint.recdef_top ->
{[],[{V,{bound,unused,[Line]}}],
add_error(Line, {variable_in_record_def,V}, St)};
error -> {[],[{V,{bound,unused,[Line]}}],St}
end
end.
%% pat_binsize_var(Variable, LineNo, VarTable, BinVarTable, State) ->
%% {UpdVarTable,UpdBinVarTable,State'}
%% A pattern variable has been found. Handle errors and warnings. Return
%% all variables as bound so errors and warnings are only reported once.
pat_binsize_var(V, Line, Vt, Bvt, St) ->
case orddict:find(V, Bvt) of
{ok,{bound,_Used,Ls}} ->
{[],[{V,{bound,used,Ls}}],St};
error ->
case orddict:find(V, Vt) of
{ok,{bound,_Used,Ls}} ->
{[{V,{bound,used,Ls}}],[],St};
{ok,{{unsafe,In},_Used,Ls}} ->
{[{V,{bound,used,Ls}}],[],
add_error(Line, {unsafe_var,V,In}, St)};
{ok,{{export,From},_Used,Ls}} ->
{[{V,{bound,used,Ls}}],[],
%% As this is not matching, exported vars are
%% probably safe.
exported_var(Line, V, From, St)};
error ->
{[{V,{bound,used,[Line]}}],[],
add_error(Line, {unbound_var,V}, St)}
end
end.
%% expr_var(Variable, LineNo, VarTable, State) ->
%% {UpdVarTable,State}
%% Check if a variable is defined, or if there is an error or warning
%% connected to its usage. Return all variables as bound so errors
%% and warnings are only reported once. As this is not matching
%% exported vars are probably safe, warn only if warn_export_vars is
%% set.
expr_var(V, Line, Vt, St0) ->
case orddict:find(V, Vt) of
{ok,{bound,_Usage,Ls}} ->
{[{V,{bound,used,Ls}}],St0};
{ok,{{unsafe,In},_Usage,Ls}} ->
{[{V,{bound,used,Ls}}],
add_error(Line, {unsafe_var,V,In}, St0)};
{ok,{{export,From},_Usage,Ls}} ->
{[{V,{bound,used,Ls}}],
exported_var(Line, V, From, St0)};
error ->
{[{V,{bound,used,[Line]}}],
add_error(Line, {unbound_var,V}, St0)}
end.
exported_var(Line, V, From, St) ->
case is_warn_enabled(export_vars, St) of
true -> add_warning(Line, {exported_var,V,From}, St);
false -> St
end.
shadow_vars(Vt, Vt0, In, St0) ->
case is_warn_enabled(shadow_vars, St0) of
true ->
foldl(fun ({V,{_,_,[L | _]}}, St) ->
add_warning(L, {shadowed_var,V,In}, St);
(_, St) -> St
end, St0, vtold(Vt, vt_no_unsafe(Vt0)));
false -> St0
end.
check_unused_vars(Vt, Vt0, St0) ->
U = unused_vars(Vt, Vt0, St0),
warn_unused_vars(U, Vt, St0).
check_old_unused_vars(Vt, Vt0, St0) ->
U = unused_vars(vtold(Vt, Vt0), [], St0),
warn_unused_vars(U, Vt, St0).
unused_vars(Vt, Vt0, _St0) ->
U0 = orddict:filter(fun (V, {_State,unused,_Ls}) ->
case atom_to_list(V) of
"_"++_ -> false;
_ -> true
end;
(_V, _How) -> false
end, Vt),
vtnew(U0, Vt0). % Only new variables.
warn_unused_vars([], Vt, St0) ->
{Vt,St0};
warn_unused_vars(U, Vt, St0) ->
St1 = case is_warn_enabled(unused_vars, St0) of
false -> St0;
true ->
foldl(fun ({V,{_,unused,Ls}}, St) ->
foldl(fun (L, St2) ->
add_warning(L, {unused_var,V},
St2)
end, St, Ls)
end, St0, U)
end,
%% Return all variables as bound so warnings are only reported once.
UVt = map(fun ({V,{State,_,Ls}}) -> {V,{State,used,Ls}} end, U),
{vtmerge(Vt, UVt), St1}.
%% vtupdate(UpdVarTable, VarTable) -> VarTable.
%% Add the variables in the updated vartable to VarTable. The variables
%% will be updated with their property in UpdVarTable. The state of
%% the variables in UpdVarTable will be returned.
vtupdate(Uvt, Vt0) ->
orddict:merge(fun (_V, {S,U1,L1}, {_S,U2,L2}) ->
{S, merge_used(U1, U2), merge_lines(L1, L2)}
end, Uvt, Vt0).
%% vtexport([Variable], From, VarTable) -> VarTable.
%% vtunsafe([Variable], From, VarTable) -> VarTable.
%% Add the variables to VarTable either as exported from From or as unsafe.
vtexport(Vs, {InTag,FileLine}, Vt0) ->
{_File,Line} = loc(FileLine),
vtupdate([{V,{{export,{InTag,Line}},unused,[]}} || V <- Vs], Vt0).
vtunsafe(Vs, {InTag,FileLine}, Vt0) ->
{_File,Line} = loc(FileLine),
vtupdate([{V,{{unsafe,{InTag,Line}},unused,[]}} || V <- Vs], Vt0).
%% vtmerge(VarTable, VarTable) -> VarTable.
%% Merge two variables tables generating a new vartable. Give priority to
%% errors then warnings.
vtmerge(Vt1, Vt2) ->
orddict:merge(fun (_V, {S1,U1,L1}, {S2,U2,L2}) ->
{merge_state(S1, S2),
merge_used(U1, U2),
merge_lines(L1, L2)}
end, Vt1, Vt2).
vtmerge(Vts) -> foldl(fun (Vt, Mvts) -> vtmerge(Vt, Mvts) end, [], Vts).
vtmerge_pat(Vt1, Vt2) ->
orddict:merge(fun (_V, {S1,_Usage1,L1}, {S2,_Usage2,L2}) ->
{merge_state(S1, S2),used, merge_lines(L1, L2)}
end, Vt1, Vt2).
merge_lines(Ls1, Ls2) ->
ordsets:union(Ls1,Ls2).
merge_state({unsafe,_F1}=S1, _S2) -> S1; %Take the error case
merge_state(_S1, {unsafe,_F2}=S2) -> S2;
merge_state(bound, S2) -> S2; %Take the warning
merge_state(S1, bound) -> S1;
merge_state({export,F1},{export,_F2}) -> %Sanity check
%% We want to report the outermost construct
{export,F1}.
merge_used(used, _Usage2) -> used;
merge_used(_Usage1, used) -> used;
merge_used(unused, unused) -> unused.
%% vtnew(NewVarTable, OldVarTable) -> NewVarTable.
%% Return all the truly new variables in NewVarTable.
vtnew(New, Old) ->
orddict:filter(fun (V, _How) -> not orddict:is_key(V, Old) end, New).
%% vtsubtract(VarTable1, VarTable2) -> NewVarTable.
%% Return all the variables in VarTable1 which don't occur in VarTable2.
%% Same thing as vtnew, but a more intuitive name for some uses.
vtsubtract(New, Old) ->
vtnew(New, Old).
%% vtold(NewVarTable, OldVarTable) -> OldVarTable.
%% Return all the truly old variables in NewVarTable.
vtold(New, Old) ->
orddict:filter(fun (V, _How) -> orddict:is_key(V, Old) end, New).
vtnames(Vt) -> [ V || {V,_How} <- Vt ].
vt_no_unsafe(Vt) -> [V || {_,{S,_U,_L}}=V <- Vt,
case S of
{unsafe,_} -> false;
_ -> true
end].
%% vunion(VarTable1, VarTable2) -> [VarName].
%% vunion([VarTable]) -> [VarName].
%% vintersection(VarTable1, VarTable2) -> [VarName].
%% vintersection([VarTable]) -> [VarName].
%% Union/intersection of names of vars in VarTable.
-ifdef(NOTUSED).
vunion(Vs1, Vs2) -> ordsets:union(vtnames(Vs1), vtnames(Vs2)).
vunion(Vss) -> foldl(fun (Vs, Uvs) ->
ordsets:union(vtnames(Vs), Uvs)
end, [], Vss).
vintersection(Vs1, Vs2) -> ordsets:intersection(vtnames(Vs1), vtnames(Vs2)).
-endif.
vintersection([Vs]) ->
vtnames(Vs); %Boundary conditions!!!
vintersection([Vs|Vss]) ->
ordsets:intersection(vtnames(Vs), vintersection(Vss));
vintersection([]) ->
[].
%% copy_expr(Expr, Line) -> Expr.
%% Make a copy of Expr converting all line numbers to Line.
copy_expr(Expr, Line) ->
modify_line(Expr, fun(_L) -> Line end).
%% modify_line(Form, Fun) -> Form
%% modify_line(Expression, Fun) -> Expression
%% Applies Fun to each line number occurrence.
modify_line(T, F0) ->
modify_line1(T, F0).
%% Forms.
modify_line1({function,F,A}, _Mf) -> {function,F,A};
modify_line1({function,M,F,A}, _Mf) -> {function,M,F,A};
modify_line1({attribute,L,record,{Name,Fields}}, Mf) ->
{attribute,Mf(L),record,{Name,modify_line1(Fields, Mf)}};
modify_line1({attribute,L,spec,{Fun,Types}}, Mf) ->
{attribute,Mf(L),spec,{Fun,modify_line1(Types, Mf)}};
modify_line1({attribute,L,type,{TypeName,TypeDef,Args}}, Mf) ->
{attribute,Mf(L),type,{TypeName,modify_line1(TypeDef, Mf),
modify_line1(Args, Mf)}};
modify_line1({attribute,L,opaque,{TypeName,TypeDef,Args}}, Mf) ->
{attribute,Mf(L),opaque,{TypeName,modify_line1(TypeDef, Mf),
modify_line1(Args, Mf)}};
modify_line1({attribute,L,Attr,Val}, Mf) -> {attribute,Mf(L),Attr,Val};
modify_line1({warning,W}, _Mf) -> {warning,W};
modify_line1({error,W}, _Mf) -> {error,W};
%% Expressions.
modify_line1({clauses,Cs}, Mf) -> {clauses,modify_line1(Cs, Mf)};
modify_line1({typed_record_field,Field,Type}, Mf) ->
{typed_record_field,modify_line1(Field, Mf),modify_line1(Type, Mf)};
modify_line1({Tag,L}, Mf) -> {Tag,Mf(L)};
modify_line1({Tag,L,E1}, Mf) ->
{Tag,Mf(L),modify_line1(E1, Mf)};
modify_line1({Tag,L,E1,E2}, Mf) ->
{Tag,Mf(L),modify_line1(E1, Mf),modify_line1(E2, Mf)};
modify_line1({bin_element,L,E1,E2,TSL}, Mf) ->
{bin_element,Mf(L),modify_line1(E1, Mf),modify_line1(E2, Mf), TSL};
modify_line1({Tag,L,E1,E2,E3}, Mf) ->
{Tag,Mf(L),modify_line1(E1, Mf),modify_line1(E2, Mf),modify_line1(E3, Mf)};
modify_line1({Tag,L,E1,E2,E3,E4}, Mf) ->
{Tag,Mf(L),
modify_line1(E1, Mf),
modify_line1(E2, Mf),
modify_line1(E3, Mf),
modify_line1(E4, Mf)};
modify_line1([H|T], Mf) ->
[modify_line1(H, Mf)|modify_line1(T, Mf)];
modify_line1([], _Mf) -> [];
modify_line1(E, _Mf) when not is_tuple(E), not is_list(E) -> E.
%% Check a record_info call. We have already checked that it is not
%% shadowed by an import.
check_record_info_call(_Line,La,[{atom,Li,Info},{atom,_Ln,Name}],St) ->
case member(Info, [fields,size]) of
true -> exist_record(La, Name, St);
false -> add_error(Li, illegal_record_info, St)
end;
check_record_info_call(Line,_La,_As,St) ->
add_error(Line, illegal_record_info, St).
has_wildcard_field([{record_field,_Lf,{var,_La,'_'},_Val}|_Fs]) -> true;
has_wildcard_field([_|Fs]) -> has_wildcard_field(Fs);
has_wildcard_field([]) -> false.
%% check_remote_function(Line, ModuleName, FuncName, [Arg], State) -> State.
%% Perform checks on known remote calls.
check_remote_function(Line, M, F, As, St0) ->
St1 = deprecated_function(Line, M, F, As, St0),
St2 = check_qlc_hrl(Line, M, F, As, St1),
format_function(Line, M, F, As, St2).
%% check_qlc_hrl(Line, ModName, FuncName, [Arg], State) -> State
%% Add warning if qlc:q/1,2 has been called but qlc.hrl has not
%% been included.
check_qlc_hrl(Line, M, F, As, St) ->
Arity = length(As),
case As of
[{lc,_L,_E,_Qs}|_] when M =:= qlc, F =:= q,
Arity < 3, not St#lint.xqlc ->
add_warning(Line, {missing_qlc_hrl, Arity}, St);
_ ->
St
end.
%% deprecated_function(Line, ModName, FuncName, [Arg], State) -> State.
%% Add warning for calls to deprecated functions.
deprecated_function(Line, M, F, As, St) ->
Arity = length(As),
MFA = {M, F, Arity},
case otp_internal:obsolete(M, F, Arity) of
{deprecated, String} when is_list(String) ->
case not is_warn_enabled(deprecated_function, St) orelse
ordsets:is_element(MFA, St#lint.not_deprecated) of
true ->
St;
false ->
add_warning(Line, {deprecated, MFA, String}, St)
end;
{deprecated, Replacement, Rel} ->
case not is_warn_enabled(deprecated_function, St) orelse
ordsets:is_element(MFA, St#lint.not_deprecated) of
true ->
St;
false ->
add_warning(Line, {deprecated, MFA, Replacement, Rel}, St)
end;
{removed, String} when is_list(String) ->
add_warning(Line, {removed, MFA, String}, St);
{removed, Replacement, Rel} ->
add_warning(Line, {removed, MFA, Replacement, Rel}, St);
no ->
St
end.
obsolete_guard({call,Line,{atom,Lr,F},As}, St0) ->
Arity = length(As),
case erl_internal:old_type_test(F, Arity) of
false ->
deprecated_function(Line, erlang, F, As, St0);
true ->
St1 = case F of
constant ->
deprecated_function(Lr, erlang, is_constant, As, St0);
_ ->
St0
end,
case is_warn_enabled(obsolete_guard, St1) of
true ->
add_warning(Lr,{obsolete_guard, {F, Arity}}, St1);
false ->
St1
end
end;
obsolete_guard(_G, St) ->
St.
%% keyword_warning(Line, Atom, State) -> State.
%% Add warning for atoms that will be reserved keywords in the future.
%% (Currently, no such keywords to warn for.)
keyword_warning(_Line, _A, St) -> St.
%% format_function(Line, ModName, FuncName, [Arg], State) -> State.
%% Add warning for bad calls to io:fwrite/format functions.
format_function(Line, M, F, As, St) ->
case is_format_function(M, F) of
true ->
case St#lint.warn_format of
Lev when Lev > 0 ->
case check_format_1(As) of
{warn,Level,Fmt,Fas} when Level =< Lev ->
add_warning(Line, {format_error,{Fmt,Fas}}, St);
_ -> St
end;
_Lev -> St
end;
false -> St
end.
is_format_function(io, fwrite) -> true;
is_format_function(io, format) -> true;
is_format_function(io_lib, fwrite) -> true;
is_format_function(io_lib, format) -> true;
is_format_function(M, F) when is_atom(M), is_atom(F) -> false.
%% check_format_1([Arg]) -> ok | {warn,Level,Format,[Arg]}.
check_format_1([Fmt]) ->
check_format_1([Fmt,{nil,0}]);
check_format_1([Fmt,As]) ->
check_format_2(Fmt, canonicalize_string(As));
check_format_1([_Dev,Fmt,As]) ->
check_format_1([Fmt,As]);
check_format_1(_As) ->
{warn,1,"format call with wrong number of arguments",[]}.
canonicalize_string({string,Line,Cs}) ->
foldr(fun (C, T) -> {cons,Line,{integer,Line,C},T} end, {nil,Line}, Cs);
canonicalize_string(Term) ->
Term.
%% check_format_2([Arg]) -> ok | {warn,Level,Format,[Arg]}.
check_format_2(Fmt, As) ->
case Fmt of
{string,_L,S} -> check_format_2a(S, As);
{atom,_L,A} -> check_format_2a(atom_to_list(A), As);
_ -> {warn,2,"format string not a textual constant",[]}
end.
check_format_2a(Fmt, As) ->
case args_list(As) of
true -> check_format_3(Fmt, As);
false -> {warn,1,"format arguments not a list",[]};
maybe -> {warn,2,"format arguments perhaps not a list",[]}
end.
%% check_format_3(FormatString, [Arg]) -> ok | {warn,Level,Format,[Arg]}.
check_format_3(Fmt, As) ->
case check_format_string(Fmt) of
{ok,Need} ->
case args_length(As) of
Len when length(Need) =:= Len -> ok;
_Len -> {warn,1,"wrong number of arguments in format call",[]}
end;
{error,S} ->
{warn,1,"format string invalid (~s)",[S]}
end.
args_list({cons,_L,_H,T}) -> args_list(T);
%% Strange case: user has written something like [a | "bcd"]; pretend
%% we don't know:
args_list({string,_L,_Cs}) -> maybe;
args_list({nil,_L}) -> true;
args_list({atom,_,_}) -> false;
args_list({integer,_,_}) -> false;
args_list({float,_,_}) -> false;
args_list(_Other) -> maybe.
args_length({cons,_L,_H,T}) -> 1 + args_length(T);
args_length({nil,_L}) -> 0.
check_format_string(Fmt) ->
extract_sequences(Fmt, []).
extract_sequences(Fmt, Need0) ->
case string:chr(Fmt, $~) of
0 -> {ok,lists:reverse(Need0)}; %That's it
Pos ->
Fmt1 = string:substr(Fmt, Pos+1), %Skip ~
case extract_sequence(1, Fmt1, Need0) of
{ok,Need1,Rest} -> extract_sequences(Rest, Need1);
Error -> Error
end
end.
extract_sequence(1, [$-,C|Fmt], Need) when C >= $0, C =< $9 ->
extract_sequence_digits(1, Fmt, Need);
extract_sequence(1, [C|Fmt], Need) when C >= $0, C =< $9 ->
extract_sequence_digits(1, Fmt, Need);
extract_sequence(1, [$-,$*|Fmt], Need) ->
extract_sequence(2, Fmt, [int|Need]);
extract_sequence(1, [$*|Fmt], Need) ->
extract_sequence(2, Fmt, [int|Need]);
extract_sequence(1, Fmt, Need) ->
extract_sequence(2, Fmt, Need);
extract_sequence(2, [$.,C|Fmt], Need) when C >= $0, C =< $9 ->
extract_sequence_digits(2, Fmt, Need);
extract_sequence(2, [$.,$*|Fmt], Need) ->
extract_sequence(3, Fmt, [int|Need]);
extract_sequence(2, [$.|Fmt], Need) ->
extract_sequence(3, Fmt, Need);
extract_sequence(2, Fmt, Need) ->
extract_sequence(4, Fmt, Need);
extract_sequence(3, [$.,$*|Fmt], Need) ->
extract_sequence(4, Fmt, [int|Need]);
extract_sequence(3, [$.,_|Fmt], Need) ->
extract_sequence(4, Fmt, Need);
extract_sequence(3, Fmt, Need) ->
extract_sequence(4, Fmt, Need);
extract_sequence(4, [$t, $c | Fmt], Need) ->
extract_sequence(5, [$c|Fmt], Need);
extract_sequence(4, [$t, $s | Fmt], Need) ->
extract_sequence(5, [$s|Fmt], Need);
extract_sequence(4, [$t, C | _Fmt], _Need) ->
{error,"invalid control ~t" ++ [C]};
extract_sequence(4, Fmt, Need) ->
extract_sequence(5, Fmt, Need);
extract_sequence(5, [C|Fmt], Need0) ->
case control_type(C, Need0) of
error -> {error,"invalid control ~" ++ [C]};
Need1 -> {ok,Need1,Fmt}
end;
extract_sequence(_, [], _Need) -> {error,"truncated"}.
extract_sequence_digits(Fld, [C|Fmt], Need) when C >= $0, C =< $9 ->
extract_sequence_digits(Fld, Fmt, Need);
extract_sequence_digits(Fld, Fmt, Need) ->
extract_sequence(Fld+1, Fmt, Need).
control_type($~, Need) -> Need;
control_type($c, Need) -> [int|Need];
control_type($f, Need) -> [float|Need];
control_type($e, Need) -> [float|Need];
control_type($g, Need) -> [float|Need];
control_type($s, Need) -> [string|Need];
control_type($w, Need) -> [term|Need];
control_type($p, Need) -> [term|Need];
control_type($W, Need) -> [int,term|Need]; %% Note: reversed
control_type($P, Need) -> [int,term|Need]; %% Note: reversed
control_type($b, Need) -> [term|Need];
control_type($B, Need) -> [term|Need];
control_type($x, Need) -> [string,term|Need]; %% Note: reversed
control_type($X, Need) -> [string,term|Need]; %% Note: reversed
control_type($+, Need) -> [term|Need];
control_type($#, Need) -> [term|Need];
control_type($n, Need) -> Need;
control_type($i, Need) -> [term|Need];
control_type(_C, _Need) -> error.
%% In syntax trees, module/package names are atoms or lists of atoms.
package_to_string(A) when is_atom(A) -> atom_to_list(A);
package_to_string(L) when is_list(L) -> packages:concat(L).
expand_package({atom,L,A} = M, St0) ->
St1 = keyword_warning(L, A, St0),
case dict:find(A, St1#lint.mod_imports) of
{ok, A1} ->
{{atom,L,A1}, St1};
error ->
Name = atom_to_list(A),
case packages:is_valid(Name) of
true ->
case packages:is_segmented(Name) of
true ->
{M, St1};
false ->
M1 = packages:concat(St1#lint.package,
Name),
{{atom,L,list_to_atom(M1)}, St1}
end;
false ->
St2 = add_error(L, {bad_module_name, Name}, St1),
{error, St2}
end
end;
expand_package(M, St0) ->
L = element(2, M),
case erl_parse:package_segments(M) of
error ->
{error, St0};
M1 ->
Name = package_to_string(M1),
case packages:is_valid(Name) of
true ->
{{atom,L,list_to_atom(Name)}, St0};
false ->
St1 = add_error(L, {bad_module_name, Name}, St0),
{error, St1}
end
end.
%% Prebuild set of local functions (to override auto-import)
local_functions(Forms) ->
gb_sets:from_list([ {Func,Arity} || {function,_,Func,Arity,_} <- Forms ]).
%% Predicate to find out if the function is locally defined
is_local_function(LocalSet,{Func,Arity}) ->
gb_sets:is_element({Func,Arity},LocalSet).
%% Predicate to see if a function is explicitly imported
is_imported_function(ImportSet,{Func,Arity}) ->
case orddict:find({Func,Arity}, ImportSet) of
{ok,_Mod} -> true;
error -> false
end.
%% Predicate to see if a function is explicitly imported from the erlang module
is_imported_from_erlang(ImportSet,{Func,Arity}) ->
case orddict:find({Func,Arity}, ImportSet) of
{ok,erlang} -> true;
_ -> false
end.
%% Build set of functions where auto-import is explicitly supressed
auto_import_suppressed(CompileFlags) ->
L0 = [ X || {no_auto_import,X} <- CompileFlags ],
L1 = [ {Y,Z} || {Y,Z} <- lists:flatten(L0), is_atom(Y), is_integer(Z) ],
gb_sets:from_list(L1).
%% Predicate to find out if autoimport is explicitly supressed for a function
is_autoimport_suppressed(NoAutoSet,{Func,Arity}) ->
gb_sets:is_element({Func,Arity},NoAutoSet).
%% Predicate to find out if a function specific bif-clash supression (old deprecated) is present
bif_clash_specifically_disabled(St,{F,A}) ->
Nowarn = nowarn_function(nowarn_bif_clash, St#lint.compile),
lists:member({F,A},Nowarn).
%% Predicate to find out if an autoimported guard_bif is not overriden in some way
%% Guard Bif without module name is disallowed if
%% * It is overridden by local function
%% * It is overridden by -import and that import is not of itself (i.e. from module erlang)
%% * The autoimport is suppressed or it's not reimported by -import directive
%% Otherwise it's OK (given that it's actually a guard bif and actually is autoimported)
no_guard_bif_clash(St,{F,A}) ->
(
(not is_local_function(St#lint.locals,{F,A}))
andalso
(
(not is_imported_function(St#lint.imports,{F,A})) orelse
is_imported_from_erlang(St#lint.imports,{F,A})
)
andalso
(
(not is_autoimport_suppressed(St#lint.no_auto, {F,A})) orelse
is_imported_from_erlang(St#lint.imports,{F,A})
)
).
