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-rw-r--r--lib/kernel/src/code.erl160
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.