Merge branch 'bjorn/eliminate-sys_pre_expand/OTP-13856'

* bjorn/eliminate-sys_pre_expand/OTP-13856:
  Remove sys_pre_expand
  xref: Eliminate use of sys_pre_expand
  debugger: Eliminate use of sys_pre_expand
  compiler: Eliminate use of sys_pre_expand
  shell_SUITE: Eliminate references to sys_pre_expand in comments
  qlc_pt: Simplify code because of updated erl_expand_records
  Teach erl_expand_records to translate module-less calls
  erl_internal: Add add_predefined_functions/1
  cover: Remove always stale comment

4 files changed, 50 insertions, 13 deletions

diff --git a/lib/tools/src/cover.erl b/lib/tools/src/cover.erl
index 92c10cc306..e2db4f0148 100644
--- a/lib/tools/src/cover.erl
+++ b/lib/tools/src/cover.erl
@@ -2053,7 +2053,7 @@ munge_expr({bin_element,Line,Value,Size,TypeSpecifierList}, Vars) ->
     {MungedValue,Vars2} = munge_expr(Value, Vars),
     {MungedSize,Vars3} = munge_expr(Size, Vars2),
     {{bin_element,Line,MungedValue,MungedSize,TypeSpecifierList},Vars3};
-munge_expr(Form, Vars) -> % var|char|integer|float|string|atom|nil|eof|default
+munge_expr(Form, Vars) ->
     {Form, Vars}.
 
 munge_exprs([Expr|Exprs], Vars, MungedExprs) when Vars#vars.is_guard=:=true,
diff --git a/lib/tools/src/xref_base.erl b/lib/tools/src/xref_base.erl
index f298a1ce81..8d2cc07e40 100644
--- a/lib/tools/src/xref_base.erl
+++ b/lib/tools/src/xref_base.erl
@@ -809,7 +809,8 @@ abst(File, Builtins, _Mode = functions) ->
                   {exports,X0}, {attributes,A}]}} ->
 	    %% R9C-
             Forms0 = epp:interpret_file_attribute(Code),
-	    {_,_,Forms,_} = sys_pre_expand:module(Forms0, []),
+	    Forms1 = erl_expand_records:module(Forms0, []),
+	    Forms = erl_internal:add_predefined_functions(Forms1),
 	    X = mfa_exports(X0, A, M),
             D = deprecated(A, X, M),
 	    xref_reader:module(M, Forms, Builtins, X, D);
diff --git a/lib/tools/src/xref_reader.erl b/lib/tools/src/xref_reader.erl
index 41b93caaeb..6c4a1c4d8e 100644
--- a/lib/tools/src/xref_reader.erl
+++ b/lib/tools/src/xref_reader.erl
@@ -42,17 +42,15 @@
 	 %% experimental; -xref(FunEdge) is recognized.
 	 lattrs=[],            % local calls, {{mfa(),mfa()},Line}
 	 xattrs=[],            % external calls, -"-
-	 battrs=[]             % badly formed xref attributes, term().
+	 battrs=[]	       % badly formed xref attributes, term().
 	 }).
 
 -include("xref.hrl").
 
-%% sys_pre_expand has modified the forms slightly compared to what
-%% erl_id_trans recognizes.
-
 %% The versions of the abstract code are as follows:
-%% R7: abstract_v1
-%% R8: abstract_v2
+%% R7:  abstract_v1
+%% R8:  abstract_v2
+%% R9C: raw_abstract_v1
 
 %% -> {ok, Module, {DefAt, CallAt, LC, XC, X, Attrs}, Unresolved}} | EXIT
 %% Attrs = {ALC, AXC, Bad}
@@ -92,7 +90,12 @@ form({function, Anno, Name, Arity, Clauses}, S) ->
     Line = erl_anno:line(Anno),
     S2 = S1#xrefr{def_at = [{MFA,Line} | S#xrefr.def_at]},
     S3 = clauses(Clauses, S2),
-    S3#xrefr{function = []}.
+    S3#xrefr{function = []};
+form(_, S) ->
+    %% OTP 20. Other uninteresting forms such as {eof, _} and {warning, _}.
+    %% Exposed because sys_pre_expand is no longer run.
+    S.
+
 
 clauses(Cls, S) ->
     #xrefr{funvars = FunVars, matches = Matches} = S,
@@ -109,6 +112,8 @@ clauses([{clause, _Line, _H, G, B} | Cs], FunVars, Matches, S) ->
 clauses([], _FunVars, _Matches, S) ->
     S.
 
+attr(NotList, Ln, M, Fun, AL, AX, B, S) when not is_list(NotList) ->
+    attr([NotList], Ln, M, Fun, AL, AX, B, S);
 attr([E={From, To} | As], Ln, M, Fun, AL, AX, B, S) ->
     case mfa(From, M) of
 	{_, _, MFA} when MFA =:= Fun; [] =:= Fun ->
@@ -154,6 +159,15 @@ expr({'try',_Line,Es,Scs,Ccs,As}, S) ->
     S2 = clauses(Scs, S1),
     S3 = clauses(Ccs, S2),
     expr(As, S3);
+expr({'fun', Line, {function,M,F,A}}, S)
+  when is_atom(M), is_atom(F), is_integer(A) ->
+    %% This is the old format for external funs, generated by a pre-R15
+    %% compiler. Exposed in OTP 20 because sys_pre_expand is no longer
+    %% run.
+    Fun = {'fun', Line, {function, {atom,Line,M},
+			 {atom,Line,F},
+			 {integer,Line,A}}},
+    expr(Fun, S);
 expr({'fun', Line, {function, {atom,_,Mod},
 		    {atom,_,Name},
 		    {integer,_,Arity}}}, S) ->
@@ -168,14 +182,21 @@ expr({'fun', Line, {function, Mod, Name, _Arity}}, S) ->
     %% New format in R15. M:F/A (one or more variables).
     As = {var, Line, '_'},
     external_call(erlang, apply, [Mod, Name, As], Line, true, S);
+%% Only abstract_v1 and abstract_v2.
 expr({'fun', Line, {function, Name, Arity}, _Extra}, S) ->
     %% Added in R8.
     handle_call(local, S#xrefr.module, Name, Arity, Line, S);
 expr({'fun', _Line, {clauses, Cs}, _Extra}, S) ->
     clauses(Cs, S);
-expr({named_fun, _Line, '_', Cs, _Extra}, S) ->
+%% End abstract_v1 and abstract_v2.
+expr({'fun', Line, {function, Name, Arity}}, S) ->
+    %% Added in OTP 20.
+    handle_call(local, S#xrefr.module, Name, Arity, Line, S);
+expr({'fun', _Line, {clauses, Cs}}, S) ->
+    clauses(Cs, S);
+expr({named_fun, _Line, '_', Cs}, S) ->
     clauses(Cs, S);
-expr({named_fun, _Line, Name, Cs, _Extra}, S) ->
+expr({named_fun, _Line, Name, Cs}, S) ->
     S1 = S#xrefr{funvars = [Name | S#xrefr.funvars]},
     clauses(Cs, S1);
 expr({call, Line, {atom, _, Name}, As}, S) ->
@@ -193,7 +214,12 @@ expr({match, _Line, {var,_,Var}, {'fun', _, {clauses, Cs}, _Extra}}, S) ->
     %% that are passed around by the "expansion" of list comprehension.
     S1 = S#xrefr{funvars = [Var | S#xrefr.funvars]},
     clauses(Cs, S1);
-expr({match, _Line, {var,_,Var}, {named_fun, _, _, _, _} = Fun}, S) ->
+expr({match, _Line, {var,_,Var}, {'fun', _, {clauses, Cs}}}, S) ->
+    %% OTP 20. Exposed because sys_pre_expand is no longer run.
+    S1 = S#xrefr{funvars = [Var | S#xrefr.funvars]},
+    clauses(Cs, S1);
+expr({match, _Line, {var,_,Var}, {named_fun, _, _, _} = Fun}, S) ->
+    %% OTP 20. Exposed because sys_pre_expand is no longer run.
     S1 = S#xrefr{funvars = [Var | S#xrefr.funvars]},
     expr(Fun, S1);
 expr({match, _Line, {var,_,Var}, E}, S) ->
@@ -295,10 +321,17 @@ check_funarg(W, ArgsList, Line, S) ->
     expr(ArgsList, S1).
 
 funarg({'fun', _, _Clauses, _Extra}, _S) -> true;
+funarg({'fun', _, {clauses, _}}, _S) ->
+    %% OTP 20. sys_pre_expand not run.
+    true;
+funarg({'fun', _, {function, _, _}}, _S) ->
+    %% OTP 20. sys_pre_expand not run.
+    true;
 funarg({'fun', _, {function,_,_,_}}, _S) ->
     %% New abstract format for fun M:F/A in R15.
     true;
-funarg({named_fun, _, _, _, _}, _S) ->
+funarg({named_fun, _, _, _}, _S) ->
+    %% OTP 20. sys_pre_expand not run.
     true;
 funarg({var, _, Var}, S) -> member(Var, S#xrefr.funvars);
 funarg(_, _S) -> false.
diff --git a/lib/tools/test/xref_SUITE.erl b/lib/tools/test/xref_SUITE.erl
index 01dbac6ecb..f308ea1204 100644
--- a/lib/tools/test/xref_SUITE.erl
+++ b/lib/tools/test/xref_SUITE.erl
@@ -1222,6 +1222,9 @@ read2(Conf) when is_list(Conf) ->
               f() ->
                   %% Duplicated unresolved calls are ignored:
                   (f())(foo,bar),(f())(foo,bar). % POS1
+
+              %% Warning forms must be ignored.
+              -warning(must_not_crash).
              ">>,
     ok = file:write_file(File, Test),
     {ok, read2} = compile:file(File, [debug_info,{outdir,Dir}]),