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/lib/stdlib/src/beam_lib.erl

https://github.com/cobusc/otp
Erlang | 1176 lines | 952 code | 151 blank | 73 comment | 9 complexity | 03822b71c16cbd34c752916621d5518c MD5 | raw file
   1%%
   2%% %CopyrightBegin%
   3%%
   4%% Copyright Ericsson AB 2000-2018. All Rights Reserved.
   5%%
   6%% Licensed under the Apache License, Version 2.0 (the "License");
   7%% you may not use this file except in compliance with the License.
   8%% You may obtain a copy of the License at
   9%%
  10%%     http://www.apache.org/licenses/LICENSE-2.0
  11%%
  12%% Unless required by applicable law or agreed to in writing, software
  13%% distributed under the License is distributed on an "AS IS" BASIS,
  14%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15%% See the License for the specific language governing permissions and
  16%% limitations under the License.
  17%%
  18%% %CopyrightEnd%
  19%%
  20-module(beam_lib).
  21-behaviour(gen_server).
  22
  23%% Avoid warning for local function error/1 clashing with autoimported BIF.
  24-compile({no_auto_import,[error/1]}).
  25%% Avoid warning for local function error/2 clashing with autoimported BIF.
  26-compile({no_auto_import,[error/2]}).
  27-export([info/1,
  28	 cmp/2,
  29	 cmp_dirs/2,
  30	 chunks/2,
  31	 chunks/3,
  32	 all_chunks/1,
  33	 diff_dirs/2,
  34	 strip/1,
  35	 strip_files/1,
  36	 strip_release/1,
  37	 build_module/1,
  38	 version/1,
  39	 md5/1,
  40	 format_error/1]).
  41
  42%% The following functions implement encrypted debug info.
  43
  44-export([crypto_key_fun/1, clear_crypto_key_fun/0]).
  45-export([init/1,handle_call/3,handle_cast/2,handle_info/2,
  46	 terminate/2,code_change/3]).
  47-export([make_crypto_key/2, get_crypto_key/1]).	%Utilities used by compiler
  48
  49-export_type([attrib_entry/0, compinfo_entry/0, labeled_entry/0, label/0]).
  50
  51-import(lists, [append/1, delete/2, foreach/2, keysort/2, 
  52		member/2, reverse/1, sort/1, splitwith/2]).
  53
  54%%-------------------------------------------------------------------------
  55
  56-type beam() :: module() | file:filename() | binary().
  57-type debug_info() :: {DbgiVersion :: atom(), Backend :: module(), Data :: term()} | 'no_debug_info'.
  58
  59-type forms()     :: [erl_parse:abstract_form() | erl_parse:form_info()].
  60
  61-type abst_code() :: {AbstVersion :: atom(), forms()} | 'no_abstract_code'.
  62-type dataB()     :: binary().
  63-type index()     :: non_neg_integer().
  64-type label()     :: integer().
  65
  66-type chunkid()   :: nonempty_string(). % approximation of the strings below
  67%% "Abst" | "Dbgi" | "Attr" | "CInf" | "ExpT" | "ImpT" | "LocT" | "Atom" | "AtU8".
  68-type chunkname() :: 'abstract_code' | 'debug_info'
  69                   | 'attributes' | 'compile_info'
  70                   | 'exports' | 'labeled_exports'
  71                   | 'imports' | 'indexed_imports'
  72                   | 'locals' | 'labeled_locals'
  73                   | 'atoms'.
  74-type chunkref()  :: chunkname() | chunkid().
  75
  76-type attrib_entry()   :: {Attribute :: atom(), [AttributeValue :: term()]}.
  77-type compinfo_entry() :: {InfoKey :: atom(), term()}.
  78-type labeled_entry()  :: {Function :: atom(), arity(), label()}.
  79
  80-type chunkdata() :: {chunkid(), dataB()}
  81                   | {'abstract_code', abst_code()}
  82                   | {'debug_info', debug_info()}
  83                   | {'attributes', [attrib_entry()]}
  84                   | {'compile_info', [compinfo_entry()]}
  85                   | {'exports', [{atom(), arity()}]}
  86                   | {'labeled_exports', [labeled_entry()]}
  87                   | {'imports', [mfa()]}
  88                   | {'indexed_imports', [{index(), module(), Function :: atom(), arity()}]}
  89                   | {'locals', [{atom(), arity()}]}
  90                   | {'labeled_locals', [labeled_entry()]}
  91                   | {'atoms', [{integer(), atom()}]}.
  92
  93%% Error reasons
  94-type info_rsn()  :: {'chunk_too_big', file:filename(),
  95		      chunkid(), ChunkSize :: non_neg_integer(),
  96                      FileSize :: non_neg_integer()}
  97                   | {'invalid_beam_file', file:filename(),
  98                      Position :: non_neg_integer()}
  99                   | {'invalid_chunk', file:filename(), chunkid()}
 100                   | {'missing_chunk', file:filename(), chunkid()}
 101                   | {'not_a_beam_file', file:filename()}
 102                   | {'file_error', file:filename(), file:posix()}.
 103-type chnk_rsn()  :: {'unknown_chunk', file:filename(), atom()}
 104                   | {'key_missing_or_invalid', file:filename(),
 105		      'abstract_code' | 'debug_info'}
 106                   | info_rsn().
 107-type cmp_rsn()   :: {'modules_different', module(), module()}
 108                   | {'chunks_different', chunkid()}
 109                   | 'different_chunks'
 110                   | info_rsn().
 111
 112%%-------------------------------------------------------------------------
 113
 114%%
 115%%  Exported functions
 116%%
 117
 118-spec info(Beam) -> [InfoPair] | {'error', 'beam_lib', info_rsn()} when
 119      Beam :: beam(),
 120      InfoPair :: {'file', Filename :: file:filename()}
 121                | {'binary', Binary :: binary()}
 122                | {'module', Module :: module()}
 123                | {'chunks', [{ChunkId :: chunkid(),
 124                               Pos :: non_neg_integer(),
 125                               Size :: non_neg_integer()}]}.
 126
 127info(File) ->
 128    read_info(beam_filename(File)).
 129
 130-spec chunks(Beam, ChunkRefs) ->
 131                    {'ok', {module(), [chunkdata()]}} |
 132                    {'error', 'beam_lib', chnk_rsn()} when
 133      Beam :: beam(),
 134      ChunkRefs :: [chunkref()].
 135
 136chunks(File, Chunks) ->
 137    read_chunk_data(File, Chunks).
 138
 139-spec chunks(Beam, ChunkRefs, Options) ->
 140                    {'ok', {module(), [ChunkResult]}} |
 141                    {'error', 'beam_lib', chnk_rsn()} when
 142      Beam :: beam(),
 143      ChunkRefs :: [chunkref()],
 144      Options :: ['allow_missing_chunks'],
 145      ChunkResult :: chunkdata() | {ChunkRef :: chunkref(), 'missing_chunk'}.
 146
 147chunks(File, Chunks, Options) ->
 148    try read_chunk_data(File, Chunks, Options)
 149    catch Error -> Error end.
 150
 151-spec all_chunks(beam()) ->
 152           {'ok', 'beam_lib', [{chunkid(), dataB()}]} | {'error', 'beam_lib', info_rsn()}.
 153
 154all_chunks(File) ->
 155    read_all_chunks(File).
 156
 157-spec cmp(Beam1, Beam2) -> 'ok' | {'error', 'beam_lib', cmp_rsn()} when
 158      Beam1 :: beam(),
 159      Beam2 :: beam().
 160
 161cmp(File1, File2) ->
 162    try cmp_files(File1, File2)
 163    catch Error -> Error end.
 164
 165-spec cmp_dirs(Dir1, Dir2) ->
 166           {Only1, Only2, Different} | {'error', 'beam_lib', Reason} when
 167      Dir1 :: atom() | file:filename(),
 168      Dir2 :: atom() | file:filename(),
 169      Only1 :: [file:filename()],
 170      Only2 :: [file:filename()],
 171      Different :: [{Filename1 :: file:filename(), Filename2 :: file:filename()}],
 172      Reason :: {'not_a_directory', term()} | info_rsn().
 173
 174cmp_dirs(Dir1, Dir2) ->
 175    catch compare_dirs(Dir1, Dir2).
 176
 177-spec diff_dirs(Dir1, Dir2) -> 'ok' | {'error', 'beam_lib', Reason} when
 178      Dir1 :: atom() | file:filename(),
 179      Dir2 :: atom() | file:filename(),
 180      Reason :: {'not_a_directory', term()} | info_rsn().
 181
 182diff_dirs(Dir1, Dir2) ->
 183    catch diff_directories(Dir1, Dir2).
 184
 185-spec strip(Beam1) ->
 186        {'ok', {module(), Beam2}} | {'error', 'beam_lib', info_rsn()} when
 187      Beam1 :: beam(),
 188      Beam2 :: beam().
 189
 190strip(FileName) ->
 191    try strip_file(FileName)
 192    catch Error -> Error end.
 193    
 194-spec strip_files(Files) ->
 195        {'ok', [{module(), Beam}]} | {'error', 'beam_lib', info_rsn()} when
 196      Files :: [beam()],
 197      Beam :: beam().
 198
 199strip_files(Files) when is_list(Files) ->
 200    try strip_fils(Files)
 201    catch Error -> Error end.
 202
 203-spec strip_release(Dir) ->
 204        {'ok', [{module(), file:filename()}]}
 205      | {'error', 'beam_lib', Reason} when
 206      Dir :: atom() | file:filename(),
 207      Reason :: {'not_a_directory', term()} | info_rsn().
 208
 209strip_release(Root) ->
 210    catch strip_rel(Root).
 211
 212-spec version(Beam) ->
 213                     {'ok', {module(), [Version :: term()]}} |
 214                     {'error', 'beam_lib', chnk_rsn()} when
 215      Beam :: beam().
 216
 217version(File) ->
 218    case catch read_chunk_data(File, [attributes]) of
 219	{ok, {Module, [{attributes, Attrs}]}} ->
 220	    {vsn, Version} = lists:keyfind(vsn, 1, Attrs),
 221	    {ok, {Module, Version}};
 222	Error ->
 223	    Error
 224    end.
 225
 226-spec md5(Beam) ->
 227        {'ok', {module(), MD5}} | {'error', 'beam_lib', chnk_rsn()} when
 228      Beam :: beam(),
 229      MD5 :: binary().
 230
 231md5(File) ->
 232    case catch read_significant_chunks(File, md5_chunks()) of
 233	{ok, {Module, Chunks0}} ->
 234	    Chunks = filter_funtab(Chunks0),
 235	    {ok, {Module, erlang:md5([C || {_Id, C} <- Chunks])}};
 236	Error ->
 237	    Error
 238    end.
 239
 240-spec format_error(Reason) -> io_lib:chars() when
 241      Reason :: term().
 242
 243format_error({error, Error}) ->
 244    format_error(Error);
 245format_error({error, Module, Error}) ->
 246    Module:format_error(Error);
 247format_error({unknown_chunk, File, ChunkName}) ->
 248    io_lib:format("~tp: Cannot find chunk ~p~n", [File, ChunkName]);
 249format_error({invalid_chunk, File, ChunkId}) ->
 250    io_lib:format("~tp: Invalid contents of chunk ~p~n", [File, ChunkId]);
 251format_error({not_a_beam_file, File}) ->
 252    io_lib:format("~tp: Not a BEAM file~n", [File]);
 253format_error({file_error, File, Reason}) ->
 254    io_lib:format("~tp: ~tp~n", [File, file:format_error(Reason)]);
 255format_error({missing_chunk, File, ChunkId}) ->
 256    io_lib:format("~tp: Not a BEAM file: no IFF \"~s\" chunk~n", 
 257		  [File, ChunkId]);
 258format_error({invalid_beam_file, File, Pos}) ->
 259    io_lib:format("~tp: Invalid format of BEAM file near byte number ~p~n", 
 260		  [File, Pos]);
 261format_error({chunk_too_big, File, ChunkId, Size, Len}) ->
 262    io_lib:format("~tp: Size of chunk \"~s\" is ~p bytes, "
 263		  "but only ~p bytes could be read~n",
 264		  [File, ChunkId, Size, Len]);
 265format_error({chunks_different, Id}) ->
 266    io_lib:format("Chunk \"~s\" differs in the two files~n", [Id]);
 267format_error(different_chunks) ->
 268    "The two files have different chunks\n";
 269format_error({modules_different, Module1, Module2}) ->
 270    io_lib:format("Module names ~p and ~p differ in the two files~n", 
 271		  [Module1, Module2]);
 272format_error({not_a_directory, Name}) ->
 273    io_lib:format("~tp: Not a directory~n", [Name]);
 274format_error({key_missing_or_invalid, File, ChunkId}) ->
 275    io_lib:format("~tp: Cannot decrypt ~ts because key is missing or invalid",
 276		  [File, ChunkId]);
 277format_error(badfun) ->
 278    "not a fun or the fun has the wrong arity";
 279format_error(exists) ->
 280    "a fun has already been installed";
 281format_error(E) ->
 282    io_lib:format("~tp~n", [E]).
 283
 284%% 
 285%% Exported functions for encrypted debug info.
 286%%
 287
 288-type mode()           :: 'des3_cbc'.
 289-type crypto_fun_arg() :: 'init'
 290                        | 'clear'
 291                        | {'debug_info', mode(), module(), file:filename()}.
 292-type crypto_fun()     :: fun((crypto_fun_arg()) -> term()).
 293
 294-spec crypto_key_fun(CryptoKeyFun) -> 'ok' | {'error', Reason} when
 295      CryptoKeyFun :: crypto_fun(),
 296      Reason :: badfun | exists | term().
 297
 298crypto_key_fun(F) ->
 299    call_crypto_server({crypto_key_fun, F}).
 300
 301-spec clear_crypto_key_fun() -> 'undefined' | {'ok', Result} when
 302      Result :: 'undefined' | term().
 303
 304clear_crypto_key_fun() ->
 305    call_crypto_server(clear_crypto_key_fun).
 306
 307-spec make_crypto_key(mode(), string()) ->
 308        {mode(), [binary()], binary(), integer()}.
 309
 310make_crypto_key(des3_cbc=Type, String) ->
 311    <<K1:8/binary,K2:8/binary>> = First = erlang:md5(String),
 312    <<K3:8/binary,IVec:8/binary>> = erlang:md5([First|reverse(String)]),
 313    {Type,[K1,K2,K3],IVec,8}.
 314
 315-spec build_module(Chunks) -> {'ok', Binary} when
 316      Chunks :: [{chunkid(), dataB()}],
 317      Binary :: binary().
 318
 319build_module(Chunks0) ->
 320    Chunks = list_to_binary(build_chunks(Chunks0)),
 321    Size = byte_size(Chunks),
 322    0 = Size rem 4, % Assertion: correct padding?
 323    {ok, <<"FOR1", (Size+4):32, "BEAM", Chunks/binary>>}.
 324
 325
 326%%
 327%%  Local functions
 328%%
 329
 330read_info(File) ->
 331    try
 332        {ok, Module, Data} = scan_beam(File, info),
 333        [if
 334             is_binary(File) -> {binary, File};
 335             true -> {file, File}
 336         end, {module, Module}, {chunks, Data}]
 337    catch Error -> Error end.
 338
 339diff_directories(Dir1, Dir2) ->
 340    {OnlyDir1, OnlyDir2, Diff} = compare_dirs(Dir1, Dir2),
 341    diff_only(Dir1, OnlyDir1),
 342    diff_only(Dir2, OnlyDir2),
 343    foreach(fun(D) -> io:format("** different: ~tp~n", [D]) end, Diff),
 344    ok.
 345
 346diff_only(_Dir, []) -> 
 347    ok;
 348diff_only(Dir, Only) ->
 349    io:format("Only in ~tp: ~tp~n", [Dir, Only]).
 350
 351%% -> {OnlyInDir1, OnlyInDir2, Different} | throw(Error)
 352compare_dirs(Dir1, Dir2) ->
 353    R1 = sofs:relation(beam_files(Dir1)),
 354    R2 = sofs:relation(beam_files(Dir2)),
 355    F1 = sofs:domain(R1),
 356    F2 = sofs:domain(R2),
 357    {O1, Both, O2} = sofs:symmetric_partition(F1, F2),
 358    OnlyL1 = sofs:image(R1, O1),
 359    OnlyL2 = sofs:image(R2, O2),
 360    B1 = sofs:to_external(sofs:restriction(R1, Both)),
 361    B2 = sofs:to_external(sofs:restriction(R2, Both)),
 362    Diff = compare_files(B1, B2, []),
 363    {sofs:to_external(OnlyL1), sofs:to_external(OnlyL2), Diff}.
 364
 365compare_files([], [], Acc) ->
 366    lists:reverse(Acc);
 367compare_files([{_,F1} | R1], [{_,F2} | R2], Acc) ->
 368    NAcc = case catch cmp_files(F1, F2) of
 369	       {error, _Mod, _Reason} ->
 370		   [{F1, F2} | Acc];
 371	       ok ->
 372		   Acc
 373	   end,
 374    compare_files(R1, R2, NAcc).
 375
 376beam_files(Dir) ->
 377    ok = assert_directory(Dir),
 378    L = filelib:wildcard(filename:join(Dir, "*.beam")),
 379    [{filename:basename(Path), Path} || Path <- L].
 380
 381%% -> ok | throw(Error)
 382cmp_files(File1, File2) ->
 383    {ok, {M1, L1}} = read_all_but_useless_chunks(File1),
 384    {ok, {M2, L2}} = read_all_but_useless_chunks(File2),
 385    if
 386	M1 =:= M2 ->
 387	    cmp_lists(L1, L2);
 388	true ->
 389	    error({modules_different, M1, M2})
 390    end.
 391
 392cmp_lists([], []) ->
 393    ok;
 394cmp_lists([{Id, C1} | R1], [{Id, C2} | R2]) ->
 395    if
 396	C1 =:= C2 ->
 397	    cmp_lists(R1, R2);
 398	true ->
 399	    error({chunks_different, Id})
 400    end;
 401cmp_lists(_, _) ->
 402    error(different_chunks).
 403    
 404strip_rel(Root) ->
 405    ok = assert_directory(Root),
 406    strip_fils(filelib:wildcard(filename:join(Root, "lib/*/ebin/*.beam"))).
 407
 408%% -> {ok, [{Mod, BinaryOrFileName}]} | throw(Error)
 409strip_fils(Files) ->
 410    {ok, [begin {ok, Reply} = strip_file(F), Reply end || F <- Files]}.
 411
 412%% -> {ok, {Mod, FileName}} | {ok, {Mod, binary()}} | throw(Error)
 413strip_file(File) ->
 414    {ok, {Mod, Chunks}} = read_significant_chunks(File, significant_chunks()),
 415    {ok, Stripped0} = build_module(Chunks),
 416    Stripped = compress(Stripped0),
 417    case File of
 418	_ when is_binary(File) ->
 419	    {ok, {Mod, Stripped}};
 420	_ ->
 421	    FileName = beam_filename(File),
 422	    case file:open(FileName, [raw, binary, write]) of
 423		{ok, Fd} ->
 424		    case file:write(Fd, Stripped) of
 425			ok ->
 426			    ok = file:close(Fd),
 427			    {ok, {Mod, FileName}};
 428			Error ->
 429			    ok = file:close(Fd),
 430			    file_error(FileName, Error)
 431		    end;
 432		Error ->
 433		    file_error(FileName, Error)
 434	    end
 435    end.
 436
 437build_chunks([{Id, Data} | Chunks]) ->
 438    BId = list_to_binary(Id),
 439    Size = byte_size(Data),
 440    Chunk = [<<BId/binary, Size:32>>, Data | pad(Size)],
 441    [Chunk | build_chunks(Chunks)];
 442build_chunks([]) -> 
 443    [].
 444
 445pad(Size) ->
 446    case Size rem 4 of
 447	0 -> [];
 448	Rem -> lists:duplicate(4 - Rem, 0)
 449    end.
 450
 451%% -> {ok, {Module, Chunks}} | throw(Error)
 452read_all_but_useless_chunks(File0) when is_atom(File0);
 453					is_list(File0);
 454					is_binary(File0) ->
 455    File = beam_filename(File0),
 456    {ok, Module, ChunkIds0} = scan_beam(File, info),
 457    ChunkIds = [Name || {Name,_,_} <- ChunkIds0,
 458			not is_useless_chunk(Name)],
 459    {ok, Module, Chunks} = scan_beam(File, ChunkIds),
 460    {ok, {Module, lists:reverse(Chunks)}}.
 461
 462is_useless_chunk("CInf") -> true;
 463is_useless_chunk(_) -> false.
 464
 465%% -> {ok, {Module, Chunks}} | throw(Error)
 466read_significant_chunks(File, ChunkList) ->
 467    case read_chunk_data(File, ChunkList, [allow_missing_chunks]) of
 468	{ok, {Module, Chunks0}} ->
 469	    Mandatory = mandatory_chunks(),
 470	    Chunks = filter_significant_chunks(Chunks0, Mandatory, File, Module),
 471	    {ok, {Module, Chunks}}
 472    end.
 473
 474filter_significant_chunks([{_, Data}=Pair|Cs], Mandatory, File, Mod)
 475  when is_binary(Data) ->
 476    [Pair|filter_significant_chunks(Cs, Mandatory, File, Mod)];
 477filter_significant_chunks([{Id, missing_chunk}|Cs], Mandatory, File, Mod) ->
 478    case member(Id, Mandatory) of
 479	false ->
 480	    filter_significant_chunks(Cs, Mandatory, File, Mod);
 481	true ->
 482	    error({missing_chunk, File, Id})
 483    end;
 484filter_significant_chunks([], _, _, _) -> [].
 485
 486filter_funtab([{"FunT"=Tag, <<L:4/binary, Data0/binary>>}|Cs]) ->
 487    Data = filter_funtab_1(Data0, <<0:32>>),
 488    Funtab = <<L/binary, (iolist_to_binary(Data))/binary>>,
 489    [{Tag, Funtab}|filter_funtab(Cs)];
 490filter_funtab([H|T]) ->
 491    [H|filter_funtab(T)];
 492filter_funtab([]) -> [].
 493
 494filter_funtab_1(<<Important:20/binary,_OldUniq:4/binary,T/binary>>, Zero) ->
 495    [Important,Zero|filter_funtab_1(T, Zero)];
 496filter_funtab_1(Tail, _) when is_binary(Tail) -> [Tail].
 497
 498read_all_chunks(File0) when is_atom(File0);
 499			    is_list(File0); 
 500			    is_binary(File0) ->
 501    try
 502        File = beam_filename(File0),
 503        {ok, Module, ChunkIds0} = scan_beam(File, info),
 504        ChunkIds = [Name || {Name,_,_} <- ChunkIds0],
 505        {ok, Module, Chunks} = scan_beam(File, ChunkIds),
 506        {ok, Module, lists:reverse(Chunks)}
 507    catch Error -> Error end.
 508
 509read_chunk_data(File0, ChunkNames) ->
 510    try read_chunk_data(File0, ChunkNames, [])
 511    catch Error -> Error end.
 512
 513%% -> {ok, {Module, Symbols}} | throw(Error)
 514read_chunk_data(File0, ChunkNames0, Options)
 515  when is_atom(File0); is_list(File0); is_binary(File0) ->
 516    File = beam_filename(File0),
 517    {ChunkIds, Names, Optional} = check_chunks(ChunkNames0, File, [], [], []),
 518    AllowMissingChunks = member(allow_missing_chunks, Options),
 519    {ok, Module, Chunks} = scan_beam(File, ChunkIds, AllowMissingChunks, Optional),
 520    AT = ets:new(beam_symbols, []),
 521    T = {empty, AT},
 522    try chunks_to_data(Names, Chunks, File, Chunks, Module, T, [])
 523    after ets:delete(AT) 
 524    end.
 525
 526%% -> {ok, list()} | throw(Error)
 527check_chunks([atoms | Ids], File, IL, L, O) ->
 528    check_chunks(Ids, File, ["Atom", "AtU8" | IL],
 529		 [{atom_chunk, atoms} | L], ["Atom", "AtU8" | O]);
 530check_chunks([abstract_code | Ids], File, IL, L, O) ->
 531    check_chunks(Ids, File, ["Abst", "Dbgi" | IL],
 532		 [{abst_chunk, abstract_code} | L], ["Abst", "Dbgi" | O]);
 533check_chunks([ChunkName | Ids], File, IL, L, O) when is_atom(ChunkName) ->
 534    ChunkId = chunk_name_to_id(ChunkName, File),
 535    check_chunks(Ids, File, [ChunkId | IL], [{ChunkId, ChunkName} | L], O);
 536check_chunks([ChunkId | Ids], File, IL, L, O) -> % when is_list(ChunkId)
 537    check_chunks(Ids, File, [ChunkId | IL], [{ChunkId, ChunkId} | L], O);
 538check_chunks([], _File, IL, L, O) ->
 539    {lists:usort(IL), reverse(L), O}.
 540
 541%% -> {ok, Module, Data} | throw(Error)
 542scan_beam(File, What) ->
 543    scan_beam(File, What, false, []).
 544
 545%% -> {ok, Module, Data} | throw(Error)
 546scan_beam(File, What0, AllowMissingChunks, OptionalChunks) ->
 547    case scan_beam1(File, What0) of
 548	{missing, _FD, Mod, Data, What} when AllowMissingChunks ->
 549	    {ok, Mod, [{Id, missing_chunk} || Id <- What] ++ Data};
 550	{missing, FD, Mod, Data, What} ->
 551	    case What -- OptionalChunks of
 552		[] -> {ok, Mod, Data};
 553		[Missing | _] -> error({missing_chunk, filename(FD), Missing})
 554	    end;
 555	R ->
 556	    R
 557    end.
 558
 559%% -> {ok, Module, Data} | throw(Error)
 560scan_beam1(File, What) ->
 561    FD = open_file(File),
 562    case catch scan_beam2(FD, What) of
 563	Error when error =:= element(1, Error) ->
 564	    throw(Error);
 565	R ->
 566	    R
 567    end.
 568
 569scan_beam2(FD, What) ->
 570    case pread(FD, 0, 12) of
 571	{NFD, {ok, <<"FOR1", _Size:32, "BEAM">>}} ->
 572	    Start = 12,
 573	    scan_beam(NFD, Start, What, 17, []);
 574	_Error -> 
 575	    error({not_a_beam_file, filename(FD)})
 576    end.
 577
 578scan_beam(_FD, _Pos, [], Mod, Data) when Mod =/= 17 ->
 579    {ok, Mod, Data};    
 580scan_beam(FD, Pos, What, Mod, Data) ->
 581    case pread(FD, Pos, 8) of
 582	{_NFD, eof} when Mod =:= 17 ->
 583	    error({missing_chunk, filename(FD), "Atom"});	    
 584	{_NFD, eof} when What =:= info ->
 585	    {ok, Mod, reverse(Data)};
 586	{NFD, eof} ->
 587	    {missing, NFD, Mod, Data, What};
 588	{NFD, {ok, <<IdL:4/binary, Sz:32>>}} ->
 589	    Id = binary_to_list(IdL),
 590	    Pos1 = Pos + 8,
 591	    Pos2 = (4 * trunc((Sz+3) / 4)) + Pos1,
 592	    get_data(What, Id, NFD, Sz, Pos1, Pos2, Mod, Data);
 593	{_NFD, {ok, _ChunkHead}} ->
 594	    error({invalid_beam_file, filename(FD), Pos})
 595    end.
 596
 597get_atom_data(Cs, Id, FD, Size, Pos, Pos2, Data, Encoding) ->
 598    NewCs = del_chunk(Id, Cs),
 599    {NFD, Chunk} = get_chunk(Id, Pos, Size, FD),
 600    <<_Num:32, Chunk2/binary>> = Chunk,
 601    {Module, _} = extract_atom(Chunk2, Encoding),
 602    C = case Cs of
 603	    info -> 
 604		{Id, Pos, Size};
 605	    _ -> 
 606		{Id, Chunk}
 607	end,
 608    scan_beam(NFD, Pos2, NewCs, Module, [C | Data]).
 609
 610get_data(Cs, "Atom" = Id, FD, Size, Pos, Pos2, _Mod, Data) ->
 611    get_atom_data(Cs, Id, FD, Size, Pos, Pos2, Data, latin1);
 612get_data(Cs, "AtU8" = Id, FD, Size, Pos, Pos2, _Mod, Data) ->
 613    get_atom_data(Cs, Id, FD, Size, Pos, Pos2, Data, utf8);
 614get_data(info, Id, FD, Size, Pos, Pos2, Mod, Data) ->
 615    scan_beam(FD, Pos2, info, Mod, [{Id, Pos, Size} | Data]);
 616get_data(Chunks, Id, FD, Size, Pos, Pos2, Mod, Data) ->
 617    {NFD, NewData} = case member(Id, Chunks) of
 618			 true ->
 619			     {FD1, Chunk} = get_chunk(Id, Pos, Size, FD),
 620			     {FD1, [{Id, Chunk} | Data]};
 621			 false ->
 622			     {FD, Data}
 623	      end,
 624    NewChunks = del_chunk(Id, Chunks),
 625    scan_beam(NFD, Pos2, NewChunks, Mod, NewData).
 626     
 627del_chunk(_Id, info) ->
 628    info;
 629del_chunk(Id, Chunks) ->
 630    delete(Id, Chunks).
 631
 632%% -> {NFD, binary()} | throw(Error)
 633get_chunk(Id, Pos, Size, FD) ->
 634    case pread(FD, Pos, Size) of
 635	{NFD, eof} when Size =:= 0 -> % cannot happen
 636	    {NFD, <<>>};
 637	{_NFD, eof} when Size > 0 ->
 638	    error({chunk_too_big, filename(FD), Id, Size, 0});
 639	{_NFD, {ok, Chunk}} when Size > byte_size(Chunk) ->
 640	    error({chunk_too_big, filename(FD), Id, Size, byte_size(Chunk)});
 641	{NFD, {ok, Chunk}} -> % when Size =:= size(Chunk)
 642	    {NFD, Chunk}
 643    end.
 644
 645chunks_to_data([{atom_chunk, Name} | CNs], Chunks, File, Cs, Module, Atoms, L) ->
 646    {NewAtoms, Ret} = chunk_to_data(Name, <<"">>, File, Cs, Atoms, Module),
 647    chunks_to_data(CNs, Chunks, File, Cs, Module, NewAtoms, [Ret | L]);
 648chunks_to_data([{abst_chunk, Name} | CNs], Chunks, File, Cs, Module, Atoms, L) ->
 649    DbgiChunk = proplists:get_value("Dbgi", Chunks, <<"">>),
 650    {NewAtoms, Ret} =
 651	case catch chunk_to_data(debug_info, DbgiChunk, File, Cs, Atoms, Module) of
 652	    {DbgiAtoms, {debug_info, {debug_info_v1, Backend, Metadata}}} ->
 653		case Backend:debug_info(erlang_v1, Module, Metadata, []) of
 654		    {ok, Code} -> {DbgiAtoms, {abstract_code, {raw_abstract_v1, Code}}};
 655		    {error, _} -> {DbgiAtoms, {abstract_code, no_abstract_code}}
 656		end;
 657            {error,beam_lib,{key_missing_or_invalid,Path,debug_info}} ->
 658                error({key_missing_or_invalid,Path,abstract_code});
 659	    _ ->
 660		AbstChunk = proplists:get_value("Abst", Chunks, <<"">>),
 661		chunk_to_data(Name, AbstChunk, File, Cs, Atoms, Module)
 662	end,
 663    chunks_to_data(CNs, Chunks, File, Cs, Module, NewAtoms, [Ret | L]);
 664chunks_to_data([{Id, Name} | CNs], Chunks, File, Cs, Module, Atoms, L) ->
 665    {_Id, Chunk} = lists:keyfind(Id, 1, Chunks),
 666    {NewAtoms, Ret} = chunk_to_data(Name, Chunk, File, Cs, Atoms, Module),
 667    chunks_to_data(CNs, Chunks, File, Cs, Module, NewAtoms, [Ret | L]);
 668chunks_to_data([], _Chunks, _File, _Cs, Module, _Atoms, L) ->
 669    {ok, {Module, reverse(L)}}.
 670
 671chunk_to_data(attributes=Id, Chunk, File, _Cs, AtomTable, _Mod) ->
 672    try
 673	Term = binary_to_term(Chunk),
 674	{AtomTable, {Id, attributes(Term)}}
 675    catch
 676	error:badarg ->
 677	    error({invalid_chunk, File, chunk_name_to_id(Id, File)})
 678    end;
 679chunk_to_data(compile_info=Id, Chunk, File, _Cs, AtomTable, _Mod) ->
 680    try
 681	{AtomTable, {Id, binary_to_term(Chunk)}}
 682    catch
 683	error:badarg ->
 684	    error({invalid_chunk, File, chunk_name_to_id(Id, File)})
 685    end;
 686chunk_to_data(debug_info=Id, Chunk, File, _Cs, AtomTable, Mod) ->
 687    case Chunk of
 688	<<>> ->
 689	    {AtomTable, {Id, no_debug_info}};
 690	<<0:8,N:8,Mode0:N/binary,Rest/binary>> ->
 691	    Mode = binary_to_atom(Mode0, utf8),
 692	    Term = decrypt_chunk(Mode, Mod, File, Id, Rest),
 693	    {AtomTable, {Id, anno_from_term(Term)}};
 694	_ ->
 695	    case catch binary_to_term(Chunk) of
 696		{'EXIT', _} ->
 697		    error({invalid_chunk, File, chunk_name_to_id(Id, File)});
 698		Term ->
 699                    {AtomTable, {Id, anno_from_term(Term)}}
 700	    end
 701    end;
 702chunk_to_data(abstract_code=Id, Chunk, File, _Cs, AtomTable, Mod) ->
 703    %% Before Erlang/OTP 20.0.
 704    case Chunk of
 705	<<>> ->
 706	    {AtomTable, {Id, no_abstract_code}};
 707	<<0:8,N:8,Mode0:N/binary,Rest/binary>> ->
 708	    Mode = binary_to_atom(Mode0, utf8),
 709	    Term = decrypt_chunk(Mode, Mod, File, Id, Rest),
 710	    {AtomTable, {Id, old_anno_from_term(Term)}};
 711	_ ->
 712	    case catch binary_to_term(Chunk) of
 713		{'EXIT', _} ->
 714		    error({invalid_chunk, File, chunk_name_to_id(Id, File)});
 715		Term ->
 716                    try
 717                        {AtomTable, {Id, old_anno_from_term(Term)}}
 718                    catch
 719                        _:_ ->
 720                            error({invalid_chunk, File,
 721                                   chunk_name_to_id(Id, File)})
 722                    end
 723	    end
 724    end;
 725chunk_to_data(atoms=Id, _Chunk, _File, Cs, AtomTable0, _Mod) ->
 726    AtomTable = ensure_atoms(AtomTable0, Cs),
 727    Atoms = ets:tab2list(AtomTable),
 728    {AtomTable, {Id, lists:sort(Atoms)}};
 729chunk_to_data(ChunkName, Chunk, File,
 730	      Cs, AtomTable, _Mod) when is_atom(ChunkName) ->
 731    case catch symbols(Chunk, AtomTable, Cs, ChunkName) of
 732	{ok, NewAtomTable, S} ->
 733	    {NewAtomTable, {ChunkName, S}};
 734	{'EXIT', _} ->
 735	    error({invalid_chunk, File, chunk_name_to_id(ChunkName, File)})
 736    end;
 737chunk_to_data(ChunkId, Chunk, _File, 
 738	      _Cs, AtomTable, _Module) when is_list(ChunkId) ->
 739    {AtomTable, {ChunkId, Chunk}}. % Chunk is a binary
 740
 741chunk_name_to_id(indexed_imports, _) -> "ImpT";
 742chunk_name_to_id(imports, _)         -> "ImpT";
 743chunk_name_to_id(exports, _)         -> "ExpT";
 744chunk_name_to_id(labeled_exports, _) -> "ExpT";
 745chunk_name_to_id(locals, _)          -> "LocT";
 746chunk_name_to_id(labeled_locals, _)  -> "LocT";
 747chunk_name_to_id(attributes, _)      -> "Attr";
 748chunk_name_to_id(abstract_code, _)   -> "Abst";
 749chunk_name_to_id(debug_info, _)      -> "Dbgi";
 750chunk_name_to_id(compile_info, _)    -> "CInf";
 751chunk_name_to_id(Other, File) -> 
 752    error({unknown_chunk, File, Other}).
 753
 754%% Extract attributes
 755
 756attributes(Attrs) ->
 757    attributes(keysort(1, Attrs), []).
 758
 759attributes([], R) ->
 760    reverse(R);
 761attributes(L, R) ->
 762    K = element(1, hd(L)),
 763    {L1, L2} = splitwith(fun(T) -> element(1, T) =:= K end, L),
 764    V = append([A || {_, A} <- L1]),
 765    attributes(L2, [{K, V} | R]).
 766
 767%% Extract symbols
 768
 769symbols(<<_Num:32, B/binary>>, AT0, Cs, Name) ->
 770    AT = ensure_atoms(AT0, Cs),
 771    symbols1(B, AT, Name, [], 1).
 772
 773symbols1(<<I1:32, I2:32, I3:32, B/binary>>, AT, Name, S, Cnt) ->
 774    Symbol = symbol(Name, AT, I1, I2, I3, Cnt),
 775    symbols1(B, AT, Name, [Symbol|S], Cnt+1);
 776symbols1(<<>>, AT, _Name, S, _Cnt) ->
 777    {ok, AT, sort(S)}.
 778
 779symbol(indexed_imports, AT, I1, I2, I3, Cnt) ->
 780    {Cnt, atm(AT, I1), atm(AT, I2), I3};
 781symbol(imports, AT, I1, I2, I3, _Cnt) ->
 782    {atm(AT, I1), atm(AT, I2), I3};
 783symbol(labeled_exports, AT, I1, I2, I3, _Cnt) ->
 784    {atm(AT, I1), I2, I3};
 785symbol(labeled_locals, AT, I1, I2, I3, _Cnt) ->
 786    {atm(AT, I1), I2, I3};
 787symbol(_, AT, I1, I2, _I3, _Cnt) ->
 788    {atm(AT, I1), I2}.
 789
 790atm(AT, N) ->
 791    [{_N, S}] = ets:lookup(AT, N),
 792    S.
 793
 794%% AT is updated.
 795ensure_atoms({empty, AT}, Cs) ->
 796    case lists:keyfind("AtU8", 1, Cs) of
 797	{_Id, AtomChunk} when is_binary(AtomChunk) ->
 798	    extract_atoms(AtomChunk, AT, utf8);
 799	_ ->
 800	    {_Id, AtomChunk} = lists:keyfind("Atom", 1, Cs),
 801	    extract_atoms(AtomChunk, AT, latin1)
 802    end,
 803    AT;
 804ensure_atoms(AT, _Cs) ->
 805    AT.
 806
 807extract_atoms(<<_Num:32, B/binary>>, AT, Encoding) ->
 808    extract_atoms(B, 1, AT, Encoding).
 809
 810extract_atoms(<<>>, _I, _AT, _Encoding) ->
 811    true;
 812extract_atoms(B, I, AT, Encoding) ->
 813    {Atom, B1} = extract_atom(B, Encoding),
 814    true = ets:insert(AT, {I, Atom}),
 815    extract_atoms(B1, I+1, AT, Encoding).
 816
 817extract_atom(<<Len, B/binary>>, Encoding) ->
 818    <<SB:Len/binary, Tail/binary>> = B,
 819    {binary_to_atom(SB, Encoding), Tail}.
 820
 821%%% Utils.
 822
 823-record(bb, {pos = 0 :: integer(),
 824	     bin :: binary(),
 825	     source :: binary() | string()}).
 826
 827open_file(<<"FOR1",_/binary>>=Binary) ->
 828    #bb{bin = Binary, source = Binary};
 829open_file(Binary0) when is_binary(Binary0) ->
 830    Binary = uncompress(Binary0),
 831    #bb{bin = Binary, source = Binary};
 832open_file(FileName) ->
 833    case file:open(FileName, [read, raw, binary]) of
 834	{ok, Fd} ->
 835	    read_all(Fd, FileName, []);
 836	Error ->
 837	    file_error(FileName, Error)
 838    end.
 839
 840read_all(Fd, FileName, Bins) ->
 841    case file:read(Fd, 1 bsl 18) of
 842	{ok, Bin} ->
 843	    read_all(Fd, FileName, [Bin | Bins]);
 844	eof ->
 845	    ok = file:close(Fd),
 846	    #bb{bin = uncompress(reverse(Bins)), source = FileName};
 847	Error ->
 848	    ok = file:close(Fd),
 849	    file_error(FileName, Error)
 850    end.
 851
 852pread(FD, AtPos, Size) ->
 853    #bb{pos = Pos, bin = Binary} = FD,
 854    Skip = AtPos-Pos,
 855    case Binary of
 856	<<_:Skip/binary, B:Size/binary, Bin/binary>> ->
 857	    NFD = FD#bb{pos = AtPos+Size, bin = Bin},
 858	    {NFD, {ok, B}};
 859	<<_:Skip/binary, Bin/binary>> when byte_size(Bin) > 0 ->
 860	    NFD = FD#bb{pos = AtPos+byte_size(Bin), bin = <<>>},
 861	    {NFD, {ok, Bin}};
 862        _ ->
 863            {FD, eof}
 864    end.
 865
 866filename(BB) when is_binary(BB#bb.source) ->
 867    BB#bb.source;
 868filename(BB) -> 
 869    list_to_atom(BB#bb.source).    
 870
 871beam_filename(Bin) when is_binary(Bin) ->
 872    Bin;
 873beam_filename(File) ->
 874    filename:rootname(File, ".beam") ++ ".beam".
 875
 876
 877uncompress(Binary0) ->
 878    {ok, Fd} = ram_file:open(Binary0, [write, binary]),
 879    {ok, _} = ram_file:uncompress(Fd),
 880    {ok, Binary} = ram_file:get_file(Fd),
 881    ok = ram_file:close(Fd),
 882    Binary.
 883
 884compress(Binary0) ->
 885    {ok, Fd} = ram_file:open(Binary0, [write, binary]),
 886    {ok, _} = ram_file:compress(Fd),
 887    {ok, Binary} = ram_file:get_file(Fd),
 888    ok = ram_file:close(Fd),
 889    Binary.
 890
 891%% -> ok | throw(Error)
 892assert_directory(FileName) ->
 893    case filelib:is_dir(FileName) of
 894	true ->
 895	    ok;
 896	false ->
 897	    error({not_a_directory, FileName})
 898    end.
 899
 900-spec file_error(file:filename(), {'error',atom()}) -> no_return().
 901
 902file_error(FileName, {error, Reason}) ->
 903    error({file_error, FileName, Reason}).
 904
 905-spec error(term()) -> no_return().
 906
 907error(Reason) ->
 908    throw({error, ?MODULE, Reason}).
 909
 910%% The following chunks must be kept when stripping a BEAM file.
 911
 912significant_chunks() ->
 913    ["Line" | md5_chunks()].
 914
 915%% The following chunks are significant when calculating the MD5
 916%% for a module. They are listed in the order that they should be MD5:ed.
 917
 918md5_chunks() ->
 919    ["Atom", "AtU8", "Code", "StrT", "ImpT", "ExpT", "FunT", "LitT"].
 920
 921%% The following chunks are mandatory in every Beam file.
 922
 923mandatory_chunks() ->
 924    ["Code", "ExpT", "ImpT", "StrT"].
 925
 926%%% ====================================================================
 927%%% The rest of the file handles encrypted debug info.
 928%%%
 929%%% Encrypting the debug info is only useful if you want to
 930%%% have the debug info available all the time (maybe even in a live
 931%%% system), but don't want to risk that anyone else but yourself
 932%%% can use it.
 933%%% ====================================================================
 934
 935-record(state, {crypto_key_f :: crypto_fun() | 'undefined'}).
 936
 937-define(CRYPTO_KEY_SERVER, beam_lib__crypto_key_server).
 938
 939decrypt_chunk(Type, Module, File, Id, Bin) ->
 940    try
 941	KeyString = get_crypto_key({debug_info, Type, Module, File}),
 942	{Type,Key,IVec,_BlockSize} = make_crypto_key(Type, KeyString),
 943	ok = start_crypto(),
 944	NewBin = crypto:block_decrypt(Type, Key, IVec, Bin),
 945	binary_to_term(NewBin)
 946    catch
 947	_:_ ->
 948	    error({key_missing_or_invalid, File, Id})
 949    end.
 950
 951old_anno_from_term({raw_abstract_v1, Forms}) ->
 952    {raw_abstract_v1, anno_from_forms(Forms)};
 953old_anno_from_term({Tag, Forms}) when Tag =:= abstract_v1;
 954                                      Tag =:= abstract_v2 ->
 955    try {Tag, anno_from_forms(Forms)}
 956    catch
 957        _:_ ->
 958            {Tag, Forms}
 959    end;
 960old_anno_from_term(T) ->
 961    T.
 962
 963anno_from_term({debug_info_v1=Tag1, erl_abstract_code=Tag2, {Forms, Opts}}) ->
 964    try {Tag1, Tag2, {anno_from_forms(Forms), Opts}}
 965    catch
 966        _:_ ->
 967            {Tag1, Tag2, {Forms, Opts}}
 968    end;
 969anno_from_term(T) ->
 970    T.
 971
 972anno_from_forms(Forms0) ->
 973    %% Forms with record field types created before OTP 19.0 are
 974    %% replaced by well-formed record forms holding the type
 975    %% information.
 976    Forms = epp:restore_typed_record_fields(Forms0),
 977    [erl_parse:anno_from_term(Form) || Form <- Forms].
 978
 979start_crypto() ->
 980    case crypto:start() of
 981	{error, {already_started, _}} ->
 982	    ok;
 983	ok ->
 984	    ok
 985    end.
 986
 987get_crypto_key(What) ->
 988    call_crypto_server({get_crypto_key, What}).
 989
 990call_crypto_server(Req) ->
 991    try 
 992	gen_server:call(?CRYPTO_KEY_SERVER, Req, infinity)
 993    catch
 994	exit:{noproc,_} ->
 995	    %% Not started.
 996	    call_crypto_server_1(Req);
 997	exit:{normal,_} ->
 998	    %% The process finished just as we called it.
 999	    call_crypto_server_1(Req)
1000    end.
1001
1002call_crypto_server_1(Req) ->
1003    case gen_server:start({local,?CRYPTO_KEY_SERVER}, ?MODULE, [], []) of
1004	{ok, _} -> ok;
1005	{error, {already_started, _}} -> ok
1006    end,
1007    erlang:yield(),
1008    call_crypto_server(Req).
1009
1010-spec init([]) -> {'ok', #state{}}.
1011
1012init([]) ->
1013    {ok, #state{}}.
1014
1015-type calls() :: 'clear_crypto_key_fun'
1016               | {'crypto_key_fun', _}
1017               | {'get_crypto_key', _}.
1018
1019-spec handle_call(calls(), {pid(), term()}, #state{}) ->
1020        {'noreply', #state{}} |
1021	{'reply', 'error' | {'error','badfun' | 'exists'}, #state{}} |
1022	{'stop', 'normal', 'undefined' | {'ok', term()}, #state{}}.
1023
1024handle_call({get_crypto_key, _}=R, From, #state{crypto_key_f=undefined}=S) ->
1025    case crypto_key_fun_from_file() of
1026	error ->
1027	    {reply, error, S};
1028	F when is_function(F) ->
1029	    %% The init function for the fun has already been called.
1030	    handle_call(R, From, S#state{crypto_key_f=F})
1031    end;
1032handle_call({get_crypto_key, What}, From, #state{crypto_key_f=F}=S) ->
1033    try
1034	Result = F(What),
1035	%% The result may hold information that we don't want 
1036	%% lying around. Reply first, then GC, then noreply.
1037	gen_server:reply(From, Result),
1038	erlang:garbage_collect(),
1039	{noreply, S}
1040    catch
1041	_:_ ->
1042	    {reply, error, S}
1043    end;
1044handle_call({crypto_key_fun, F}, {_,_} = From, S) ->
1045    case S#state.crypto_key_f of
1046	undefined ->
1047	    if is_function(F, 1) ->
1048		    {Result, Fun, Reply} = 
1049			case catch F(init) of
1050			    ok ->
1051				{true, F, ok};
1052			    {ok, F1} when is_function(F1) ->
1053				if
1054				    is_function(F1, 1) ->
1055					{true, F1, ok};
1056				    true ->
1057					{false, undefined, 
1058					 {error, badfun}}
1059				end;
1060			    {error, Reason} ->
1061				{false, undefined, {error, Reason}};
1062			    {'EXIT', Reason} ->
1063				{false, undefined, {error, Reason}}
1064			end,
1065		    gen_server:reply(From, Reply),
1066		    erlang:garbage_collect(),
1067		    NewS = case Result of
1068			       true ->
1069				   S#state{crypto_key_f = Fun};
1070			       false ->
1071				   S
1072			   end,
1073		    {noreply, NewS};
1074	       true ->
1075		    {reply, {error, badfun}, S}
1076	    end;
1077	OtherF when is_function(OtherF) ->
1078	    {reply, {error, exists}, S}
1079    end;
1080handle_call(clear_crypto_key_fun, _From, S) ->
1081    case S#state.crypto_key_f of
1082	undefined ->
1083	    {stop,normal,undefined,S};
1084	F ->
1085	    Result = (catch F(clear)),
1086	    {stop,normal,{ok,Result},S}
1087    end.
1088
1089-spec handle_cast(term(), #state{}) -> {'noreply', #state{}}.
1090
1091handle_cast(_, State) ->
1092    {noreply, State}.
1093
1094-spec handle_info(term(), #state{}) -> {'noreply', #state{}}.
1095
1096handle_info(_, State) ->
1097    {noreply, State}.
1098
1099-spec code_change(term(), #state{}, term()) -> {'ok', #state{}}.
1100
1101code_change(_OldVsn, State, _Extra) ->
1102    {ok, State}.
1103
1104-spec terminate(term(), #state{}) -> 'ok'.
1105
1106terminate(_Reason, _State) ->
1107    ok.
1108
1109crypto_key_fun_from_file() ->
1110    case init:get_argument(home) of
1111	{ok,[[Home]]} ->
1112	    crypto_key_fun_from_file_1([".",Home]);
1113	_ ->
1114	    crypto_key_fun_from_file_1(["."])
1115    end.
1116
1117crypto_key_fun_from_file_1(Path) ->
1118    case f_p_s(Path, ".erlang.crypt") of
1119	{ok, KeyInfo, _} ->
1120	    try_load_crypto_fun(KeyInfo);
1121	_ ->
1122	    error
1123    end.
1124
1125f_p_s(P, F) ->
1126    case file:path_script(P, F) of
1127	{error, enoent} ->
1128	    {error, enoent};
1129	{error, {Line, _Mod, _Term}=E} ->
1130	    error("file:path_script(~tp,~tp): error on line ~p: ~ts~n",
1131		  [P, F, Line, file:format_error(E)]),
1132	    ok;
1133	{error, E} when is_atom(E) ->
1134	    error("file:path_script(~tp,~tp): ~ts~n",
1135		  [P, F, file:format_error(E)]),
1136	    ok;
1137	Other ->
1138	    Other
1139    end.
1140
1141try_load_crypto_fun(KeyInfo) when is_list(KeyInfo) ->
1142    T = ets:new(keys, [private, set]),
1143    foreach(
1144      fun({debug_info, Mode, M, Key}) when is_atom(M) ->
1145	      ets:insert(T, {{debug_info,Mode,M,[]}, Key});
1146	 ({debug_info, Mode, [], Key}) ->
1147	      ets:insert(T, {{debug_info, Mode, [], []}, Key});
1148	 (Other) ->
1149	      error("unknown key: ~p~n", [Other])
1150      end, KeyInfo),
1151    fun({debug_info, Mode, M, F}) ->
1152	    alt_lookup_key(
1153	      [{debug_info,Mode,M,F},
1154	       {debug_info,Mode,M,[]},
1155	       {debug_info,Mode,[],[]}], T);
1156       (clear) ->
1157	    ets:delete(T);
1158       (_) ->
1159	    error
1160    end;
1161try_load_crypto_fun(KeyInfo) ->
1162    error("unrecognized crypto key info: ~p\n", [KeyInfo]).
1163
1164alt_lookup_key([H|T], Tab) ->
1165    case ets:lookup(Tab, H) of
1166	[] ->
1167	    alt_lookup_key(T, Tab);
1168	[{_, Val}] ->
1169	    Val
1170    end;
1171alt_lookup_key([], _) ->
1172    error.
1173
1174error(Fmt, Args) ->
1175    error_logger:error_msg(Fmt, Args),
1176    error.