Merge branch 'hb/dialyzer/fix_on_load/OTP-11743'

* hb/dialyzer/fix_on_load/OTP-11743:
  FIx handling of 'on_load' attribute

3 files changed, 25 insertions, 12 deletions

diff --git a/lib/dialyzer/src/dialyzer_analysis_callgraph.erl b/lib/dialyzer/src/dialyzer_analysis_callgraph.erl
index 3de020cb01..2a633c5e37 100644
--- a/lib/dialyzer/src/dialyzer_analysis_callgraph.erl
+++ b/lib/dialyzer/src/dialyzer_analysis_callgraph.erl
@@ -172,7 +172,7 @@ analysis_start(Parent, Analysis) ->
       throw:{error, _ErrorMsg} = Error -> exit(Error)
     end,
   NewPlt0 = dialyzer_plt:insert_types(Plt, dialyzer_codeserver:get_records(NewCServer)),
-  ExpTypes =  dialyzer_codeserver:get_exported_types(NewCServer),
+  ExpTypes = dialyzer_codeserver:get_exported_types(NewCServer),
   NewPlt1 = dialyzer_plt:insert_exported_types(NewPlt0, ExpTypes),
   State0 = State#analysis_state{plt = NewPlt1},
   dump_callgraph(Callgraph, State0, Analysis),
@@ -427,11 +427,8 @@ abs_get_nowarn(Abs, M) ->
     false ->
       [{M, F, A} || {function, _, F, A, _} <- Abs]; % all functions
     true ->
-      OnLoad =
-	lists:flatten([{M, F, A} || {attribute, _, on_load, {F, A}} <- Abs]),
-      OnLoad ++ [{M, F, A} ||
-		  {nowarn_unused_function, FAs} <- Opts,
-		  {F, A} <- lists:flatten([FAs])]
+      [{M, F, A} || {nowarn_unused_function, FAs} <- Opts,
+                    {F, A} <- lists:flatten([FAs])]
   end.
 
 get_exported_types_from_core(Core) ->
diff --git a/lib/dialyzer/src/dialyzer_dep.erl b/lib/dialyzer/src/dialyzer_dep.erl
index 5c1245ae47..f1ac41ff04 100644
--- a/lib/dialyzer/src/dialyzer_dep.erl
+++ b/lib/dialyzer/src/dialyzer_dep.erl
@@ -65,7 +65,7 @@ analyze(Tree) ->
   %% io:format("Handling ~w\n", [cerl:atom_val(cerl:module_name(Tree))]),
   {_, State} = traverse(Tree, map__new(), state__new(Tree), top),
   Esc = state__esc(State), 
-  %% Add dependency from 'external' to all escaping function
+  %% Add dependency from 'external' to all escaping functions
   State1 = state__add_deps(external, output(Esc), State),
   Deps = state__deps(State1),
   Calls = state__calls(State1),
@@ -486,11 +486,22 @@ all_vars(Tree, AccIn) ->
 
 state__new(Tree) ->
   Exports = set__from_list([X || X <- cerl:module_exports(Tree)]),
-  InitEsc = set__from_list([cerl_trees:get_label(Fun) 
-			    || {Var, Fun} <- cerl:module_defs(Tree),
-			       set__is_element(Var, Exports)]),
+  %% get the labels of all exported functions
+  ExpLs = [cerl_trees:get_label(Fun) || {Var, Fun} <- cerl:module_defs(Tree),
+					set__is_element(Var, Exports)],
+  %% make sure to also initiate an analysis from all functions called
+  %% from on_load attributes; in Core these exist as a list of {F,A} pairs
+  OnLoadFAs = lists:flatten([cerl:atom_val(Args)
+			     || {Attr, Args} <- cerl:module_attrs(Tree),
+				cerl:atom_val(Attr) =:= on_load]),
+  OnLoadLs = [cerl_trees:get_label(Fun)
+	      || {Var, Fun} <- cerl:module_defs(Tree),
+		 lists:member(cerl:var_name(Var), OnLoadFAs)],
+  %% init the escaping function labels to exported + called from on_load
+  InitEsc = set__from_list(OnLoadLs ++ ExpLs),
   Arities = cerl_trees:fold(fun find_arities/2, dict:new(), Tree),
-  #state{deps = map__new(), esc = InitEsc, call = map__new(), arities = Arities, letrecs = map__new()}.
+  #state{deps = map__new(), esc = InitEsc, call = map__new(),
+	 arities = Arities, letrecs = map__new()}.
 
 find_arities(Tree, AccMap) ->
   case cerl:is_c_fun(Tree) of
diff --git a/lib/dialyzer/test/small_SUITE_data/src/on_load.erl b/lib/dialyzer/test/small_SUITE_data/src/on_load.erl
index 16533a9caa..7242ac2016 100644
--- a/lib/dialyzer/test/small_SUITE_data/src/on_load.erl
+++ b/lib/dialyzer/test/small_SUITE_data/src/on_load.erl
@@ -1,4 +1,6 @@
 %%% This is to ensure that "on_load" functions are never reported as unused.
+%%% In addition, all functions called by a function in an on_load attribute
+%%% should be considered as called by an entry point of the module.
 
 -module(on_load).
 
@@ -8,4 +10,7 @@
 
 foo() -> ok.
 
-bar() -> ok.
+bar() -> gazonk(17).
+
+gazonk(N) when N < 42 -> gazonk(N+1);
+gazonk(42) -> ok.