Return nowarn_bif_clash functionality but with warning

Wrote and changed some tests in stdlib:erl_lint_SUITE

nowarn_bif_clash is obsoleted but will remove warnings and errors about bif
clashes. The recommended way is to use no_auto_import directives instead.

Hopefully erlang.erl is the only user in the world of nowarn_bif_clash.

1 files changed, 95 insertions, 38 deletions

diff --git a/lib/stdlib/src/erl_lint.erl b/lib/stdlib/src/erl_lint.erl
index acb9165ead..631ad0c1e3 100644
--- a/lib/stdlib/src/erl_lint.erl
+++ b/lib/stdlib/src/erl_lint.erl
@@ -163,6 +163,9 @@ 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(deprecated_nowarn_bif_clash) ->
+    io_lib:format("compile directive nowarn_bif_clash is deprecated,~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}) ->
@@ -188,11 +191,11 @@ 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({redefine_bif,{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({redefine_old_bif,{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]);
@@ -549,9 +552,11 @@ loc(L) ->
 forms(Forms0, St0) ->
     Forms = eval_file_attribute(Forms0, St0),
     Locals = local_functions(Forms),
-    AutoImportSupressed = auto_import_supressed(St0#lint.compile),
+    AutoImportSuppressed = auto_import_suppressed(St0#lint.compile),
+    StDeprecated = deprecated_compile_flags(Forms,St0),
     %% Line numbers are from now on pairs {File,Line}.
-    St1 = includes_qlc_hrl(Forms, St0#lint{locals = Locals, no_auto = AutoImportSupressed}),
+    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),
@@ -757,6 +762,23 @@ not_deprecated(Forms, St0) ->
     St1 = func_line_warning(bad_nowarn_deprecated_function, Bad, St0),
     St1#lint{not_deprecated = ordsets:from_list(Nowarn)}.
 
+deprecated_compile_flags(Forms, St0) ->
+    %% There are (still) no line numbers in St0#lint.compile.
+    Warnings0 =  [ {St0#lint.file,{L,erl_lint,deprecated_nowarn_bif_clash}} ||
+		    {attribute,[{line,{_,L}}],compile,nowarn_bif_clash} <- Forms ],
+    Warnings1 = [ {St0#lint.file,{L,erl_lint,deprecated_nowarn_bif_clash}} ||
+		    {attribute,[{line,{_,L}}],compile,{nowarn_bif_clash, {_,_}}} <- Forms ],
+    Disabled = (not is_warn_enabled(bif_clash, St0)),
+    Warnings = if
+		   Disabled andalso Warnings0 =:= [] ->
+		       [{St0#lint.file,{erl_lint,deprecated_nowarn_bif_clash}} | St0#lint.warnings];
+                   Disabled ->
+		       Warnings0 ++ Warnings1 ++ St0#lint.warnings;
+		   true ->
+		       Warnings1 ++ St0#lint.warnings
+	       end,
+    St0#lint{warnings=Warnings}.
+
 %% post_traversal_check(Forms, State0) -> State.
 %% Do some further checking after the forms have been traversed and
 %% data about calls etc. have been collected.
@@ -1015,7 +1037,8 @@ check_option_functions(Forms, Tag0, Type, St0) ->
                       {Tag, FAs0} <- lists:flatten([Args]),
                       Tag0 =:= Tag,
                       FA <- lists:flatten([FAs0])],
-    DefFunctions = gb_sets:to_list(St0#lint.defined) -- pseudolocals(),
+    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).
 
@@ -1108,8 +1131,10 @@ import(Line, {Mod,Fs}, St) ->
                 Efs ->
 		    {Err, St1} =
 			foldl(fun ({bif,{F,A},_}, {Err,St0}) ->
-				      Warn = is_warn_enabled(bif_clash, St0), %% PaN -> import directive
-				      AutoImpSup = is_autoimport_supressed(St0#lint.no_auto,{F,A}),
+				      %% 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 ->
@@ -1123,7 +1148,7 @@ import(Line, {Mod,Fs}, St) ->
 						      {redefine_bif_import, {F,A}},
 						      St0);
 					       true ->
-					  St0
+						   St0
 					   end};
 				  (Ef, {_Err,St0}) ->
 				      {true,add_error(Line,
@@ -1249,14 +1274,6 @@ define_function(Line, Name, Arity, St0) ->
             add_error(Line, {redefine_function,NA}, St1);
         false ->
             St2 = St1#lint{defined=gb_sets:add_element(NA, St1#lint.defined)},
-%%             St = case erl_internal:bif(Name, Arity) andalso %% PaN - Function definitions
-%% 		     (not is_function_exported(Name, Arity, St2)) andalso
-%% 		     is_warn_enabled(bif_clash, St2) andalso
-%% 		     is_bif_clash(Name,Arity,St2) andalso
-%% 		     (not is_autoimport_supressed(St0#lint.no_auto,NA)) of
-%% 		     true -> add_warning(Line, {redefine_bif,NA}, St2);
-%%                      false -> St2
-%%                   end,
             case imported(Name, Arity, St2) of
                 {yes,_M} -> add_error(Line, {define_import,NA}, St2);
                 no -> St2
@@ -1762,17 +1779,16 @@ gexpr({call,Line,{remote,_,{atom,_,erlang},{atom,_,is_record}=Isr},[_,_,_]=Args}
 gexpr({call,Line,{atom,_La,F},As}, Vt, St0) ->
     {Asvt,St1} = gexpr_list(As, Vt, St0),
     A = length(As),
-    case (not is_local_function(St1#lint.locals,{F,A})) andalso %% PaN -> Function called in guard
-	 (not is_imported_function(St1#lint.imports,{F,A})) andalso
-	 erl_internal:guard_bif(F, A) andalso
-	 (not is_autoimport_supressed(St1#lint.no_auto, {F,A})) of
+    %% 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)}
+        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),
@@ -1998,10 +2014,11 @@ expr({'fun',Line,Body}, Vt, St) ->
             {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 %% PaN - Fun expression
+            case ((not is_local_function(St#lint.locals,{F,A})) andalso
 		  (erl_internal:bif(F, A) andalso
-		   (not is_autoimport_supressed(St#lint.no_auto,{F,A})))) of
+		   (not is_autoimport_suppressed(St#lint.no_auto,{F,A})))) of
                 true -> {[],St};
                 false -> {[],call_function(Line, F, A, St)}
             end;
@@ -2036,8 +2053,9 @@ expr({call,Line,{atom,La,F},As}, Vt, St0) ->
     A = length(As),
     IsLocal = is_local_function(St2#lint.locals,{F,A}),
     IsAutoBif = erl_internal:bif(F, A),
-    AutoSupressed = is_autoimport_supressed(St2#lint.no_auto,{F,A}),
-    case ((not IsLocal) andalso IsAutoBif andalso (not AutoSupressed)) of %% PaN - function call
+    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};
@@ -2052,27 +2070,33 @@ expr({call,Line,{atom,La,F},As}, Vt, St0) ->
 			  case {F,A} of
 			      {record_info,2} ->
                                   check_record_info_call(Line,La,As,St2);
-                              N when N =:= St2#lint.func ->
-				  St2;
-                              _ ->
+                              N ->
+				  %% BifClash - function call
+				  %% Issue these warnings/errors even if it's a recursive call
 				  St3 = if
-					    (not AutoSupressed) andalso IsAutoBif ->
+					    (not AutoSuppressed) andalso IsAutoBif andalso Warn ->
 						case erl_internal:old_bif(F,A) of
 						    true ->
 							add_error
 							  (Line,
-							   {redefine_old_bif, {F,A}},
+							   {call_to_redefined_old_bif, {F,A}},
 							   St2);
 						    false ->
 							add_warning
 							  (Line,
-							   {redefine_bif, {F,A}},
+							   {call_to_redefined_bif, {F,A}},
 							   St2)
 						end;
 					    true ->
 						St2
 					end,
-				  call_function(Line, F, A, St3)
+				  %% ...but don't lint recursive calls
+				  if
+				      N =:= St3#lint.func ->
+					  St3;
+				      true ->
+					  call_function(Line, F, A, St3)
+				  end
                           end
                   end}
     end;
@@ -3502,22 +3526,55 @@ expand_package(M, St0) ->
             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.
-
-auto_import_supressed(CompileFlags) ->
+%% 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).
-
-is_autoimport_supressed(NoAutoSet,{Func,Arity}) ->
+%% 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})
+      )
+    ).