diff options
Diffstat (limited to 'lib/kernel/src/code.erl')
| -rw-r--r-- | lib/kernel/src/code.erl | 160 |
1 files changed, 126 insertions, 34 deletions
diff --git a/lib/kernel/src/code.erl b/lib/kernel/src/code.erl index 622b27080c..5a7ca493cc 100644 --- a/lib/kernel/src/code.erl +++ b/lib/kernel/src/code.erl @@ -70,7 +70,9 @@ where_is_file/2, set_primary_archive/4, clash/0, - get_mode/0]). + module_status/1, + modified_modules/0, + get_mode/0]). -deprecated({rehash,0,next_major_release}). @@ -719,38 +721,14 @@ start_get_mode() -> which(Module) when is_atom(Module) -> case is_loaded(Module) of false -> - which2(Module); + which(Module, get_path()); {file, File} -> File end. -which2(Module) -> - Base = atom_to_list(Module), - File = filename:basename(Base) ++ objfile_extension(), - Path = get_path(), - which(File, filename:dirname(Base), Path). - --spec which(file:filename(), file:filename(), [file:filename()]) -> - 'non_existing' | file:filename(). - -which(_, _, []) -> - non_existing; -which(File, Base, [Directory|Tail]) -> - Path = if - Base =:= "." -> Directory; - true -> filename:join(Directory, Base) - end, - case erl_prim_loader:list_dir(Path) of - {ok,Files} -> - case lists:member(File,Files) of - true -> - filename:append(Path, File); - false -> - which(File, Base, Tail) - end; - _Error -> - which(File, Base, Tail) - end. +which(Module, Path) when is_atom(Module) -> + File = atom_to_list(Module) ++ objfile_extension(), + where_is_file(Path, File). %% Search the code path for a specific file. Try to locate %% it in the code path cache if possible. @@ -760,13 +738,33 @@ which(File, Base, [Directory|Tail]) -> Absname :: file:filename(). where_is_file(File) when is_list(File) -> Path = get_path(), - which(File, ".", Path). + where_is_file(Path, File). + +%% To avoid unnecessary work when looking at many modules, this also +%% accepts pairs of directories and pre-fetched contents in the path +-spec where_is_file(Path :: [Dir|{Dir,Files}], Filename :: file:filename()) -> + 'non_existing' | file:filename() when + Dir :: file:filename(), Files :: [file:filename()]. --spec where_is_file(Path :: file:filename(), Filename :: file:filename()) -> - file:filename() | 'non_existing'. +where_is_file([], _) -> + non_existing; +where_is_file([{Path, Files}|Tail], File) -> + where_is_file(Tail, File, Path, Files); +where_is_file([Path|Tail], File) -> + case erl_prim_loader:list_dir(Path) of + {ok,Files} -> + where_is_file(Tail, File, Path, Files); + _Error -> + where_is_file(Tail, File) + end. -where_is_file(Path, File) when is_list(Path), is_list(File) -> - which(File, ".", Path). +where_is_file(Tail, File, Path, Files) -> + case lists:member(File, Files) of + true -> + filename:append(Path, File); + false -> + where_is_file(Tail, File) + end. -spec set_primary_archive(ArchiveFile :: file:filename(), ArchiveBin :: binary(), @@ -899,3 +897,97 @@ load_all_native_1([{Mod,BeamFilename}|T], ChunkTag) -> load_all_native_1(T, ChunkTag); load_all_native_1([], _) -> ok. + +%% Returns the status of the module in relation to object file on disk. +-spec module_status(Module :: module()) -> not_loaded | loaded | modified | removed. +module_status(Module) -> + module_status(Module, code:get_path()). + +%% Note that we don't want to go via which/1, since it doesn't look at the +%% disk contents at all if the module is already loaded. +module_status(Module, PathFiles) -> + case code:is_loaded(Module) of + false -> not_loaded; + {file, preloaded} -> loaded; + {file, cover_compiled} -> + %% cover compilation loads directly to memory and does not + %% create a beam file, so report 'modified' if a file exists + case which(Module, PathFiles) of + non_existing -> removed; + _File -> modified + end; + {file, []} -> loaded; % no beam file - generated code + {file, OldFile} when is_list(OldFile) -> + %% we don't care whether or not the file is in the same location + %% as when last loaded, as long as it can be found in the path + case which(Module, PathFiles) of + non_existing -> removed; + Path -> + case module_changed_on_disk(Module, Path) of + true -> modified; + false -> loaded + end + end + end. + +%% Detects actual code changes only, e.g. to decide whether a module should +%% be reloaded; does not care about file timestamps or compilation time +module_changed_on_disk(Module, Path) -> + MD5 = erlang:get_module_info(Module, md5), + case erlang:system_info(hipe_architecture) of + undefined -> + %% straightforward, since native is not supported + MD5 =/= beam_file_md5(Path); + Architecture -> + case code:is_module_native(Module) of + true -> + %% MD5 is for native code, so we check only the native + %% code on disk, ignoring the beam code + MD5 =/= beam_file_native_md5(Path, Architecture); + _ -> + %% MD5 is for beam code, so check only the beam code on + %% disk, even if the file contains native code as well + MD5 =/= beam_file_md5(Path) + end + end. + +beam_file_md5(Path) -> + case beam_lib:md5(Path) of + {ok,{_Mod,MD5}} -> MD5; + _ -> undefined + end. + +beam_file_native_md5(Path, Architecture) -> + try + get_beam_chunk(Path, hipe_unified_loader:chunk_name(Architecture)) + of + NativeCode when is_binary(NativeCode) -> + erlang:md5(NativeCode) + catch + _:_ -> undefined + end. + +get_beam_chunk(Path, Chunk) -> + {ok, {_, [{_, Bin}]}} = beam_lib:chunks(Path, [Chunk]), + Bin. + +%% Returns a list of all modules modified on disk. +-spec modified_modules() -> [module()]. +modified_modules() -> + PathFiles = path_files(), + [M || {M, _} <- code:all_loaded(), + module_status(M, PathFiles) =:= modified]. + +%% prefetch the directory contents of code path directories +path_files() -> + path_files(code:get_path()). + +path_files([]) -> + []; +path_files([Path|Tail]) -> + case erl_prim_loader:list_dir(Path) of + {ok, Files} -> + [{Path,Files} | path_files(Tail)]; + _Error -> + path_files(Tail) + end. |