Store abstract code in the Dbgi chunk

The new Dbgi chunk returns data in the following format:

    {debug_info_v1, Backend, Data}

This allows compilers to store the debug info in different
formats. In order to retrieve a particular format, for
instance, Erlang Abstract Format, one may invoke:

    Backend:debug_info(erlang_v1, Module, Data, Opts)

Besides introducing the chunk above, this commit also:

  * Changes beam_lib:chunk(Beam, [:abstract_code]) to
    read from the new Dbgi chunk while keeping backwards
    compatibility with old .beams

  * Adds the {debug_info, {Backend, Data}} option to
    compile:file/2 and friends that are stored in the
    Dbgi chunk. This allows the debug info encryption
    mechanism to work across compilers

  * Improves dialyzer to work directly on Core Erlang,
    allowing languages that do not have the Erlang
    Abstract Format to be dialyzer as long as they emit
    the new chunk and their backend implementation is
    available

Backwards compatibility is kept across the board except
for those calling beam_lib:chunk(Beam, ["Abst"]), as the
old chunk is no longer available. Note however the "Abst"
chunk has always been optional.

Future OTP versions may remove parsing the "Abst" chunk
altogether from beam_lib once Erlang 19 and earlier is no
longer supported.

The current Dialyzer implementation still supports earlier
.beam files and such may also be removed in future versions.

1 files changed, 147 insertions, 151 deletions

diff --git a/lib/dialyzer/src/dialyzer_utils.erl b/lib/dialyzer/src/dialyzer_utils.erl
index 9eaf95c1a2..e0497159b3 100644
--- a/lib/dialyzer/src/dialyzer_utils.erl
+++ b/lib/dialyzer/src/dialyzer_utils.erl
@@ -24,14 +24,10 @@
 -export([
 	 format_sig/1,
 	 format_sig/2,
-	 get_abstract_code_from_beam/1,
- 	 get_compile_options_from_beam/1,
-	 get_abstract_code_from_src/1,
-	 get_abstract_code_from_src/2,
-	 get_core_from_abstract_code/1,
-	 get_core_from_abstract_code/2,
 	 get_core_from_src/1,
 	 get_core_from_src/2,
+         get_core_from_beam/1,
+         get_core_from_beam/2,
 	 get_record_and_type_info/1,
 	 get_spec_info/3,
          get_fun_meta_info/3,
@@ -77,9 +73,7 @@ print_types1([{record, _Name} = Key|T], RecDict) ->
 
 %% ----------------------------------------------------------------------------
 
--type abstract_code() :: [erl_parse:abstract_form()].
 -type comp_options()  :: [compile:option()].
--type mod_or_fname()  :: module() | file:filename().
 -type fa()            :: {atom(), arity()}.
 -type codeserver()    :: dialyzer_codeserver:codeserver().
 
@@ -89,63 +83,82 @@ print_types1([{record, _Name} = Key|T], RecDict) ->
 %%
 %% ============================================================================
 
--spec get_abstract_code_from_src(mod_or_fname()) ->
-	{'ok', abstract_code()} | {'error', [string()]}.
+-type get_core_from_src_ret() :: {'ok', cerl:c_module()} | {'error', string()}.
+
+-spec get_core_from_src(file:filename()) -> get_core_from_src_ret().
 
-get_abstract_code_from_src(File) ->
-  get_abstract_code_from_src(File, src_compiler_opts()).
+get_core_from_src(File) ->
+  get_core_from_src(File, []).
 
--spec get_abstract_code_from_src(mod_or_fname(), comp_options()) ->
-	{'ok', abstract_code()} | {'error', [string()]}.
+-spec get_core_from_src(file:filename(), comp_options()) -> get_core_from_src_ret().
 
-get_abstract_code_from_src(File, Opts) ->
-  case compile:noenv_file(File, [to_pp, binary|Opts]) of
+get_core_from_src(File, Opts) ->
+  case compile:noenv_file(File, Opts ++ src_compiler_opts()) of
     error -> {error, []};
     {error, Errors, _} -> {error, format_errors(Errors)};
-    {ok, _, AbstrCode} -> {ok, AbstrCode}
+    {ok, _, Core} -> {ok, Core}
   end.
 
--type get_core_from_src_ret() :: {'ok', cerl:c_module()} | {'error', string()}.
+-type get_core_from_beam_ret() :: {'ok', cerl:c_module()} | {'error', string()}.
 
--spec get_core_from_src(file:filename()) -> get_core_from_src_ret().
+-spec get_core_from_beam(file:filename()) -> get_core_from_beam_ret().
 
-get_core_from_src(File) ->
-  get_core_from_src(File, []).
+get_core_from_beam(File) ->
+  get_core_from_beam(File, []).
 
--spec get_core_from_src(file:filename(), comp_options()) -> get_core_from_src_ret().
+-spec get_core_from_beam(file:filename(), comp_options()) -> get_core_from_beam_ret().
 
-get_core_from_src(File, Opts) ->
-  case get_abstract_code_from_src(File, Opts) of
-    {error, _} = Error -> Error;
+get_core_from_beam(File, Opts) ->
+  case beam_lib:chunks(File, [debug_info]) of
+    {ok, {Module, [{debug_info, {debug_info_v1, Backend, Metadata}}]}} ->
+      case Backend:debug_info(core_v1, Module, Metadata, Opts ++ src_compiler_opts()) of
+	{ok, Core} ->
+	  {ok, Core};
+	{error, _} ->
+	  {error, "  Could not get Core Erlang code for: " ++ File ++ "\n"}
+      end;
+    _ ->
+      deprecated_get_core_from_beam(File, Opts)
+  end.
+
+deprecated_get_core_from_beam(File, Opts) ->
+  case get_abstract_code_from_beam(File) of
+    error ->
+      {error, "  Could not get abstract code for: " ++ File ++ "\n" ++
+       "  Recompile with +debug_info or analyze starting from source code"};
     {ok, AbstrCode} ->
-      case get_core_from_abstract_code(AbstrCode, Opts) of
-	error -> {error, "  Could not get Core Erlang code from abstract code"};
-	{ok, _Core} = C -> C
+      case get_compile_options_from_beam(File) of
+        error ->
+          {error, "  Could not get compile options for: " ++ File ++ "\n" ++
+            "  Recompile or analyze starting from source code"};
+        {ok, CompOpts} ->
+          case get_core_from_abstract_code(AbstrCode, Opts ++ CompOpts) of
+            error ->
+              {error, "  Could not get core Erlang code for: " ++ File};
+            {ok, _} = Core ->
+              Core
+          end
       end
   end.
 
--spec get_abstract_code_from_beam(file:filename()) -> 'error' | {'ok', abstract_code()}.
-
 get_abstract_code_from_beam(File) ->
   case beam_lib:chunks(File, [abstract_code]) of
     {ok, {_, List}} ->
       case lists:keyfind(abstract_code, 1, List) of
-	{abstract_code, {raw_abstract_v1, Abstr}} -> {ok, Abstr};
-	_ -> error
+        {abstract_code, {raw_abstract_v1, Abstr}} -> {ok, Abstr};
+        _ -> error
       end;
     _ ->
       %% No or unsuitable abstract code.
       error
   end.
 
--spec get_compile_options_from_beam(file:filename()) -> 'error' | {'ok', [compile:option()]}.
-
 get_compile_options_from_beam(File) ->
   case beam_lib:chunks(File, [compile_info]) of
     {ok, {_, List}} ->
       case lists:keyfind(compile_info, 1, List) of
-	{compile_info, CompInfo} -> compile_info_to_options(CompInfo);
-	_ -> error
+        {compile_info, CompInfo} -> compile_info_to_options(CompInfo);
+        _ -> error
       end;
     _ ->
       %% No or unsuitable compile info.
@@ -158,15 +171,6 @@ compile_info_to_options(CompInfo) ->
     _ -> error
   end.
 
--type get_core_from_abs_ret() :: {'ok', cerl:c_module()} | 'error'.
-
--spec get_core_from_abstract_code(abstract_code()) -> get_core_from_abs_ret().
-
-get_core_from_abstract_code(AbstrCode) ->
-  get_core_from_abstract_code(AbstrCode, []).
-
--spec get_core_from_abstract_code(abstract_code(), comp_options()) -> get_core_from_abs_ret().
-
 get_core_from_abstract_code(AbstrCode, Opts) ->
   %% We do not want the parse_transforms around since we already
   %% performed them. In some cases we end up in trouble when
@@ -175,12 +179,31 @@ get_core_from_abstract_code(AbstrCode, Opts) ->
   %% Remove parse_transforms (and other options) from compile options.
   Opts2 = cleanup_compile_options(Opts),
   try compile:noenv_forms(AbstrCode1, Opts2 ++ src_compiler_opts()) of
-      {ok, _, Core} -> {ok, Core};
-      _What -> error
+    {ok, _, Core} -> {ok, Core};
+    _What -> error
   catch
     error:_ -> error
   end.
 
+cleanup_parse_transforms([{attribute, _, compile, {parse_transform, _}}|Left]) ->
+  cleanup_parse_transforms(Left);
+cleanup_parse_transforms([Other|Left]) ->
+  [Other|cleanup_parse_transforms(Left)];
+cleanup_parse_transforms([]) ->
+  [].
+
+cleanup_compile_options(Opts) ->
+  lists:filter(fun keep_compile_option/1, Opts).
+
+%% Using abstract, not asm or core.
+keep_compile_option(from_asm) -> false;
+keep_compile_option(from_core) -> false;
+%% The parse transform will already have been applied, may cause
+%% problems if it is re-applied.
+keep_compile_option({parse_transform, _}) -> false;
+keep_compile_option(warnings_as_errors) -> false;
+keep_compile_option(_) -> true.
+
 %% ============================================================================
 %%
 %%  Typed Records
@@ -189,55 +212,50 @@ get_core_from_abstract_code(AbstrCode, Opts) ->
 
 -type type_table() :: erl_types:type_table().
 
--spec get_record_and_type_info(abstract_code()) ->
-	{'ok', type_table()} | {'error', string()}.
+-spec get_record_and_type_info(cerl:module()) ->
+        {'ok', type_table()} | {'error', string()}.
 
-get_record_and_type_info(AbstractCode) ->
-  Module = get_module(AbstractCode),
-  get_record_and_type_info(AbstractCode, Module, maps:new()).
+get_record_and_type_info(Core) ->
+  Module = cerl:concrete(cerl:module_name(Core)),
+  Tuples = core_to_attr_tuples(Core),
+  get_record_and_type_info(Tuples, Module, maps:new(), "nofile").
 
--spec get_record_and_type_info(abstract_code(), module(), type_table()) ->
-	{'ok', type_table()} | {'error', string()}.
-
-get_record_and_type_info(AbstractCode, Module, RecDict) ->
-  get_record_and_type_info(AbstractCode, Module, RecDict, "nofile").
-
-get_record_and_type_info([{attribute, A, record, {Name, Fields0}}|Left],
+get_record_and_type_info([{record, Line, [{Name, Fields0}]}|Left],
 			 Module, RecDict, File) ->
   {ok, Fields} = get_record_fields(Fields0, RecDict),
   Arity = length(Fields),
-  FN = {File, erl_anno:line(A)},
+  FN = {File, Line},
   NewRecDict = maps:put({record, Name}, {FN, [{Arity,Fields}]}, RecDict),
   get_record_and_type_info(Left, Module, NewRecDict, File);
-get_record_and_type_info([{attribute, A, type, {{record, Name}, Fields0, []}}
+get_record_and_type_info([{type, Line, [{{record, Name}, Fields0, []}]}
 			  |Left], Module, RecDict, File) ->
   %% This overrides the original record declaration.
   {ok, Fields} = get_record_fields(Fields0, RecDict),
   Arity = length(Fields),
-  FN = {File, erl_anno:line(A)},
+  FN = {File, Line},
   NewRecDict = maps:put({record, Name}, {FN, [{Arity, Fields}]}, RecDict),
   get_record_and_type_info(Left, Module, NewRecDict, File);
-get_record_and_type_info([{attribute, A, Attr, {Name, TypeForm}}|Left],
+get_record_and_type_info([{Attr, Line, [{Name, TypeForm}]}|Left],
 			 Module, RecDict, File)
                when Attr =:= 'type'; Attr =:= 'opaque' ->
-  FN = {File, erl_anno:line(A)},
+  FN = {File, Line},
   try add_new_type(Attr, Name, TypeForm, [], Module, FN, RecDict) of
     NewRecDict ->
       get_record_and_type_info(Left, Module, NewRecDict, File)
   catch
     throw:{error, _} = Error -> Error
   end;
-get_record_and_type_info([{attribute, A, Attr, {Name, TypeForm, Args}}|Left],
+get_record_and_type_info([{Attr, Line, [{Name, TypeForm, Args}]}|Left],
 			 Module, RecDict, File)
                when Attr =:= 'type'; Attr =:= 'opaque' ->
-  FN = {File, erl_anno:line(A)},
+  FN = {File, Line},
   try add_new_type(Attr, Name, TypeForm, Args, Module, FN, RecDict) of
     NewRecDict ->
       get_record_and_type_info(Left, Module, NewRecDict, File)
   catch
     throw:{error, _} = Error -> Error
   end;
-get_record_and_type_info([{attribute, _, file, {IncludeFile, _}}|Left],
+get_record_and_type_info([{file, _, [{IncludeFile, _}]}|Left],
                          Module, RecDict, _File) ->
   get_record_and_type_info(Left, Module, RecDict, IncludeFile);
 get_record_and_type_info([_Other|Left], Module, RecDict, File) ->
@@ -460,23 +478,18 @@ merge_types(CServer, Plt) ->
 -type spec_map()     :: dialyzer_codeserver:contracts().
 -type callback_map() :: dialyzer_codeserver:contracts().
 
--spec get_spec_info(module(), abstract_code(), type_table()) ->
+-spec get_spec_info(module(), cerl:module(), type_table()) ->
         {'ok', spec_map(), callback_map()} | {'error', string()}.
 
-get_spec_info(ModName, AbstractCode, RecordsMap) ->
-  OptionalCallbacks0 = get_optional_callbacks(AbstractCode, ModName),
+get_spec_info(ModName, Core, RecordsMap) ->
+  Tuples = core_to_attr_tuples(Core),
+  OptionalCallbacks0 = get_optional_callbacks(Tuples, ModName),
   OptionalCallbacks = gb_sets:from_list(OptionalCallbacks0),
-  get_spec_info(AbstractCode, maps:new(), maps:new(),
+  get_spec_info(Tuples, maps:new(), maps:new(),
 		RecordsMap, ModName, OptionalCallbacks, "nofile").
 
-get_optional_callbacks(Abs, ModName) ->
-  [{ModName, F, A} || {F, A} <- get_optional_callbacks(Abs)].
-
-get_optional_callbacks(Abs) ->
-    L = [O ||
-            {attribute, _, optional_callbacks, O} <- Abs,
-            is_fa_list(O)],
-    lists:append(L).
+get_optional_callbacks(Tuples, ModName) ->
+  [{ModName, F, A} || {optional_callbacks, _, O} <- Tuples, is_fa_list(O), {F, A} <- O].
 
 %% TypeSpec is a list of conditional contracts for a function.
 %% Each contract is of the form {[Argument], Range, [Constraint]} where
@@ -484,11 +497,10 @@ get_optional_callbacks(Abs) ->
 %%  - Constraint is of the form {subtype, T1, T2} where T1 and T2
 %%    are erl_types:erl_type()
 
-get_spec_info([{attribute, Anno, Contract, {Id, TypeSpec}}|Left],
+get_spec_info([{Contract, Ln, [{Id, TypeSpec}]}|Left],
 	      SpecMap, CallbackMap, RecordsMap, ModName, OptCb, File)
   when ((Contract =:= 'spec') or (Contract =:= 'callback')),
        is_list(TypeSpec) ->
-  Ln = erl_anno:line(Anno),
   MFA = case Id of
 	  {_, _, _} = T -> T;
 	  {F, A} -> {ModName, F, A}
@@ -523,7 +535,7 @@ get_spec_info([{attribute, Anno, Contract, {Id, TypeSpec}}|Left],
       {error, flat_format("  Error while parsing contract in line ~w: ~s\n",
 			  [Ln, Error])}
   end;
-get_spec_info([{attribute, _, file, {IncludeFile, _}}|Left],
+get_spec_info([{file, _, [{IncludeFile, _}]}|Left],
 	      SpecMap, CallbackMap, RecordsMap, ModName, OptCb, _File) ->
   get_spec_info(Left, SpecMap, CallbackMap,
 		RecordsMap, ModName, OptCb, IncludeFile);
@@ -535,15 +547,25 @@ get_spec_info([], SpecMap, CallbackMap,
               _RecordsMap, _ModName, _OptCb, _File) ->
   {ok, SpecMap, CallbackMap}.
 
--spec get_fun_meta_info(module(), abstract_code(), [dial_warn_tag()]) ->
+core_to_attr_tuples(Core) ->
+  [{cerl:concrete(Key), get_core_line(cerl:get_ann(Key)), cerl:concrete(Value)} ||
+   {Key, Value} <- cerl:module_attrs(Core)].
+
+get_core_line([L | _As]) when is_integer(L) -> L;
+get_core_line([_ | As]) -> get_core_line(As);
+get_core_line([]) -> undefined.
+
+-spec get_fun_meta_info(module(), cerl:module(), [dial_warn_tag()]) ->
                 dialyzer_codeserver:fun_meta_info() | {'error', string()}.
 
-get_fun_meta_info(M, Abs, LegalWarnings) ->
+get_fun_meta_info(M, Core, LegalWarnings) ->
+  Functions = lists:map(fun cerl:var_name/1, cerl:module_vars(Core)),
   try
-    {get_nowarn_unused_function(M, Abs), get_func_suppressions(M, Abs)}
+    {get_nowarn_unused_function(M, Core, Functions),
+     get_func_suppressions(M, Core, Functions)}
   of
     {NoWarn, FuncSupp} ->
-      Warnings0 = get_options(Abs, LegalWarnings),
+      Warnings0 = get_options(Core, LegalWarnings),
       Warnings = ordsets:to_list(Warnings0),
       ModuleWarnings = [{M, W} || W <- Warnings],
       RawProps = lists:append([NoWarn, FuncSupp, ModuleWarnings]),
@@ -569,49 +591,45 @@ process_options([{{_M, _F, _A}=MFA, Opts}|Left], Warnings) ->
   end;
 process_options([], _Warnings) -> [].
 
--spec get_nowarn_unused_function(module(), abstract_code()) ->
+-spec get_nowarn_unused_function(module(), cerl:module(), [fa()]) ->
                                     [{mfa(), 'no_unused'}].
 
-get_nowarn_unused_function(M, Abs) ->
-  Opts = get_options_with_tag(compile, Abs),
+get_nowarn_unused_function(M, Core, Functions) ->
+  Opts = get_options_with_tag(compile, Core),
   Warn = erl_lint:bool_option(warn_unused_function, nowarn_unused_function,
                               true, Opts),
-  Functions = [{F, A} || {function, _, F, A, _} <- Abs],
-  AttrFile = collect_attribute(Abs, compile),
+  AttrFile = collect_attribute(Core, compile),
   TagsFaList = check_fa_list(AttrFile, nowarn_unused_function, Functions),
   FAs = case Warn of
           false -> Functions;
           true ->
-            [FA || {{nowarn_unused_function,_L,_File}, FA} <- TagsFaList]
+            [FA || {{[nowarn_unused_function],_L,_File}, FA} <- TagsFaList]
         end,
   [{{M, F, A}, no_unused} || {F, A} <- FAs].
 
--spec get_func_suppressions(module(), abstract_code()) ->
+-spec get_func_suppressions(module(), cerl:module(), [fa()]) ->
                             [{mfa(), 'nowarn_function' | dial_warn_tag()}].
 
-get_func_suppressions(M, Abs) ->
-  Functions = [{F, A} || {function, _, F, A, _} <- Abs],
-  AttrFile = collect_attribute(Abs, dialyzer),
+get_func_suppressions(M, Core, Functions) ->
+  AttrFile = collect_attribute(Core, dialyzer),
   TagsFAs = check_fa_list(AttrFile, '*', Functions),
   %% Check the options:
-  Fun = fun({{nowarn_function, _L, _File}, _FA}) -> ok;
+  Fun = fun({{[nowarn_function], _L, _File}, _FA}) -> ok;
            ({OptLFile, _FA}) ->
             _ = get_options1([OptLFile], ordsets:new())
         end,
   lists:foreach(Fun, TagsFAs),
-  [{{M, F, A}, W} || {{W, _L, _File}, {F, A}} <- TagsFAs].
+  [{{M, F, A}, W} || {{Warnings, _L, _File}, {F, A}} <- TagsFAs, W <- Warnings].
 
--spec get_options(abstract_code(), [dial_warn_tag()]) ->
+-spec get_options(cerl:module(), [dial_warn_tag()]) ->
                      ordsets:ordset(dial_warn_tag()).
 
-get_options(Abs, LegalWarnings) ->
-  AttrFile = collect_attribute(Abs, dialyzer),
+get_options(Core, LegalWarnings) ->
+  AttrFile = collect_attribute(Core, dialyzer),
   get_options1(AttrFile, LegalWarnings).
 
 get_options1([{Args, L, File}|Left], Warnings) ->
-  Opts = [O ||
-           O <- lists:flatten([Args]),
-           is_atom(O)],
+  Opts = [O || O <- Args, is_atom(O)],
   try dialyzer_options:build_warnings(Opts, Warnings) of
     NewWarnings ->
       get_options1(Left, NewWarnings)
@@ -624,19 +642,24 @@ get_options1([], Warnings) ->
   Warnings.
 
 -type collected_attribute() ::
-        {Args :: term(), erl_anno:line(), file:filename()}.
-
-collect_attribute(Abs, Tag) ->
-  collect_attribute(Abs, Tag, "nofile").
-
-collect_attribute([{attribute, L, Tag, Args}|Left], Tag, File) ->
-  CollAttr = {Args, L, File},
-  [CollAttr | collect_attribute(Left, Tag, File)];
-collect_attribute([{attribute, _, file, {IncludeFile, _}}|Left], Tag, _) ->
-  collect_attribute(Left, Tag, IncludeFile);
-collect_attribute([_Other|Left], Tag, File) ->
-  collect_attribute(Left, Tag, File);
-collect_attribute([], _Tag, _File) -> [].
+        {Args :: [term()], erl_anno:line(), file:filename()}.
+
+collect_attribute(Core, Tag) ->
+  collect_attribute(cerl:module_attrs(Core), Tag, "nofile").
+
+collect_attribute([{Key, Value}|T], Tag, File) ->
+  case cerl:concrete(Key) of
+    Tag ->
+      [{cerl:concrete(Value), get_core_line(cerl:get_ann(Key)), File} |
+       collect_attribute(T, Tag, File)];
+    file ->
+      [{IncludeFile, _}] = cerl:concrete(Value),
+      collect_attribute(T, Tag, IncludeFile);
+    _ ->
+      collect_attribute(T, Tag, File)
+  end;
+collect_attribute([], _Tag, _File) ->
+  [].
 
 -spec is_suppressed_fun(mfa(), codeserver()) -> boolean().
 
@@ -687,35 +710,6 @@ src_compiler_opts() ->
    no_inline, strict_record_tests, strict_record_updates,
    dialyzer].
 
--spec get_module(abstract_code()) -> module().
-
-get_module([{attribute, _, module, {M, _As}} | _]) -> M;
-get_module([{attribute, _, module, M} | _]) -> M;
-get_module([_ | Rest]) -> get_module(Rest).
-
--spec cleanup_parse_transforms(abstract_code()) -> abstract_code().
-
-cleanup_parse_transforms([{attribute, _, compile, {parse_transform, _}}|Left]) ->
-  cleanup_parse_transforms(Left);
-cleanup_parse_transforms([Other|Left]) ->
-  [Other|cleanup_parse_transforms(Left)];
-cleanup_parse_transforms([]) ->
-  [].
-
--spec cleanup_compile_options([compile:option()]) -> [compile:option()].
-
-cleanup_compile_options(Opts) ->
-  lists:filter(fun keep_compile_option/1, Opts).
-
-%% Using abstract, not asm or core.
-keep_compile_option(from_asm) -> false;
-keep_compile_option(from_core) -> false;
-%% The parse transform will already have been applied, may cause
-%% problems if it is re-applied.
-keep_compile_option({parse_transform, _}) -> false;
-keep_compile_option(warnings_as_errors) -> false;
-keep_compile_option(_) -> true.
-
 -spec format_errors([{module(), string()}]) -> [string()].
 
 format_errors([{Mod, Errors}|Left]) ->
@@ -741,10 +735,12 @@ format_sig(Type, RecDict) ->
 flat_format(Fmt, Lst) ->
   lists:flatten(io_lib:format(Fmt, Lst)).
 
--spec get_options_with_tag(atom(), abstract_code()) -> [term()].
+-spec get_options_with_tag(atom(), cerl:module()) -> [term()].
 
-get_options_with_tag(Tag, Abs) ->
-  lists:flatten([O || {attribute, _, Tag0, O} <- Abs, Tag =:= Tag0]).
+get_options_with_tag(Tag, Core) ->
+  [O || {Key, Value} <- cerl:module_attrs(Core),
+        cerl:concrete(Key) =:= Tag,
+        O <- cerl:concrete(Value)].
 
 %% Check F/A, and collect (unchecked) warning tags with line and file.
 -spec check_fa_list([collected_attribute()], atom(), [fa()]) ->
@@ -755,8 +751,8 @@ check_fa_list(AttrFile, Tag, Functions) ->
   check_fa_list1(AttrFile, Tag, FuncTab).
 
 check_fa_list1([{Args, L, File}|Left], Tag, Funcs) ->
-  TermsL = [{{Tag0, L, File}, Term} ||
-             {Tags, Terms0} <- lists:flatten([Args]),
+  TermsL = [{{[Tag0], L, File}, Term} ||
+             {Tags, Terms0} <- Args,
              Tag0 <- lists:flatten([Tags]),
              Tag =:= '*' orelse Tag =:= Tag0,
              Term <- lists:flatten([Terms0])],