Merge pull request #1719 from josevalim/jv-faster-dialyzer-md5

dialyzer: Compute MD5s using the .beam file (OTP-14937)

2 files changed, 13 insertions, 10 deletions

diff --git a/lib/dialyzer/src/dialyzer_plt.erl b/lib/dialyzer/src/dialyzer_plt.erl
index 95c8b5ebce..2af4534396 100644
--- a/lib/dialyzer/src/dialyzer_plt.erl
+++ b/lib/dialyzer/src/dialyzer_plt.erl
@@ -531,17 +531,19 @@ compute_md5_from_files(Files) ->
   lists:keysort(1, [{F, compute_md5_from_file(F)} || F <- Files]).
 
 compute_md5_from_file(File) ->
-  case filelib:is_regular(File) of
-    false ->
+  case beam_lib:all_chunks(File) of
+    {ok, _, Chunks} ->
+      %% We cannot use beam_lib:md5 because it does not consider
+      %% the debug_info chunk, where typespecs are likely stored.
+      %% So we consider almost all chunks except the useless ones.
+      Filtered = [[ID, Chunk] || {ID, Chunk} <- Chunks, ID =/= "CInf", ID =/= "Docs"],
+      erlang:md5(lists:sort(Filtered));
+    {error, beam_lib, {file_error, _, enoent}} ->
       Msg = io_lib:format("Not a regular file: ~ts\n", [File]),
       throw({dialyzer_error, Msg});
-    true ->
-      case dialyzer_utils:get_core_from_beam(File) of
-	{error, Error} ->
-	  throw({dialyzer_error, Error});
-	{ok, Core} ->
-	  erlang:md5(term_to_binary(Core))
-      end
+    {error, beam_lib, _} ->
+      Msg = io_lib:format("Could not compute MD5 for .beam: ~ts\n", [File]),
+      throw({dialyzer_error, Msg})
   end.
 
 init_diff_list(RemoveFiles, AddFiles) ->
diff --git a/lib/stdlib/src/beam_lib.erl b/lib/stdlib/src/beam_lib.erl
index 06c15fceda..24349c74e8 100644
--- a/lib/stdlib/src/beam_lib.erl
+++ b/lib/stdlib/src/beam_lib.erl
@@ -148,7 +148,8 @@ chunks(File, Chunks, Options) ->
     try read_chunk_data(File, Chunks, Options)
     catch Error -> Error end.
 
--spec all_chunks(beam()) -> {'ok', 'beam_lib', [{chunkid(), dataB()}]}.
+-spec all_chunks(beam()) ->
+           {'ok', 'beam_lib', [{chunkid(), dataB()}]} | {'error', 'beam_lib', info_rsn()}.
 
 all_chunks(File) ->
     read_all_chunks(File).