Merge branch 'bjorn/compiler/coverage'

* bjorn/compiler/coverage:
  v3_codegen: Remove check of operand for bs_context_to_binary
  beam_jump: Eliminate a repeated clause
  beam_asm: No longer allow iolists as contents in chunk/2
  beam_utils_SUITE: Cover more lines in beam_utils
  guard_SUITE: Add a test case to cover beam_dead:turn_op/1
  Recognize 'nil' as a literal in beam_utils:bif_to_test/3
  Cover more code in beam_bsm:btb_opt_1/3
  Add test to cover a line in v3_kernel:opt_single_valued/3

8 files changed, 129 insertions, 31 deletions

diff --git a/lib/compiler/src/beam_asm.erl b/lib/compiler/src/beam_asm.erl
index 9ecbb7884c..3dff51d7f6 100644
--- a/lib/compiler/src/beam_asm.erl
+++ b/lib/compiler/src/beam_asm.erl
@@ -240,9 +240,7 @@ build_form(Id, Chunks0) when byte_size(Id) =:= 4, is_list(Chunks0) ->
 
 chunk(Id, Contents) when byte_size(Id) =:= 4, is_binary(Contents) ->
     Size = byte_size(Contents),
-    [<<Id/binary,Size:32>>,Contents|pad(Size)];
-chunk(Id, Contents) when is_list(Contents) ->
-    chunk(Id, list_to_binary(Contents)).
+    [<<Id/binary,Size:32>>,Contents|pad(Size)].
 
 %% Build a correctly padded chunk (with a sub-header).
 
diff --git a/lib/compiler/src/beam_jump.erl b/lib/compiler/src/beam_jump.erl
index 0bcec9ce19..c33de217bd 100644
--- a/lib/compiler/src/beam_jump.erl
+++ b/lib/compiler/src/beam_jump.erl
@@ -336,17 +336,6 @@ opt([{test,_,{f,L}=Lbl,_}=I|[{label,L}|_]=Is], Acc0, St0) ->
             {Acc,St} = opt_useless_loads(Acc0, L, St0),
 	    opt(Is, Acc, St)
     end;
-opt([{test,_,{f,L}=Lbl,_}=I|[{label,L}|_]=Is], Acc0, St0) ->
-    %% Similar to the above, except we have a fall-through rather than jump
-    %%    Test Label Ops
-    %%    label Label
-    case beam_utils:is_pure_test(I) of
-	false ->
-	    opt(Is, [I|Acc0], label_used(Lbl, St0));
-	true ->
-            {Acc,St} = opt_useless_loads(Acc0, L, St0),
-	    opt(Is, Acc, St)
-    end;
 opt([{test,Test0,{f,L}=Lbl,Ops}=I|[{jump,To}|Is]=Is0], Acc, St) ->
     case is_label_defined(Is, L) of
 	false ->
diff --git a/lib/compiler/src/beam_utils.erl b/lib/compiler/src/beam_utils.erl
index 00f396c246..dd7ec4da96 100644
--- a/lib/compiler/src/beam_utils.erl
+++ b/lib/compiler/src/beam_utils.erl
@@ -32,7 +32,8 @@
 
 -import(lists, [map/2,member/2,sort/1,reverse/1,splitwith/2]).
 
--define(is_const(Val), (element(1, Val) =:= integer orelse
+-define(is_const(Val), (Val =:= nil orelse
+                        element(1, Val) =:= integer orelse
                         element(1, Val) =:= float orelse
                         element(1, Val) =:= atom orelse
                         element(1, Val) =:= literal)).
diff --git a/lib/compiler/src/v3_codegen.erl b/lib/compiler/src/v3_codegen.erl
index 006a6a82d2..535c0679d8 100644
--- a/lib/compiler/src/v3_codegen.erl
+++ b/lib/compiler/src/v3_codegen.erl
@@ -1634,12 +1634,7 @@ bif_cg(#k_bif{op=#k_remote{mod=#k_atom{val=erlang},name=#k_atom{val=Name}},
 
 internal_cg(bs_context_to_binary=Instr, [Src0], [], Le, Vdb, Bef, St0) ->
     [Src] = cg_reg_args([Src0], Bef),
-    case is_register(Src) of
-	false ->
-	    {[],clear_dead(Bef, Le#l.i, Vdb), St0};
-	true ->
-	    {[{Instr,Src}],clear_dead(Bef, Le#l.i, Vdb), St0}
-    end;
+    {[{Instr,Src}],clear_dead(Bef, Le#l.i, Vdb), St0};
 internal_cg(dsetelement, [Index0,Tuple0,New0], _Rs, Le, Vdb, Bef, St0) ->
     [New,Tuple,{integer,Index1}] = cg_reg_args([New0,Tuple0,Index0], Bef),
     Index = Index1-1,
@@ -2571,10 +2566,6 @@ find_stack(_, [], _) -> error.
 
 on_stack(V, Stk) -> keymember(V, 1, Stk).
 
-is_register({x,_}) -> true;
-is_register({yy,_}) -> true;
-is_register(_) -> false.
-
 %% put_catch(CatchTag, Stack) -> Stack'
 %% drop_catch(CatchTag, Stack) -> Stack'
 %%  Special interface for putting and removing catch tags, to ensure that
diff --git a/lib/compiler/test/beam_utils_SUITE.erl b/lib/compiler/test/beam_utils_SUITE.erl
index 710cb050d4..3a07f3923f 100644
--- a/lib/compiler/test/beam_utils_SUITE.erl
+++ b/lib/compiler/test/beam_utils_SUITE.erl
@@ -24,7 +24,8 @@
 	 apply_fun/1,apply_mf/1,bs_init/1,bs_save/1,
 	 is_not_killed/1,is_not_used_at/1,
 	 select/1,y_catch/1,otp_8949_b/1,liveopt/1,coverage/1,
-	 y_registers/1]).
+         y_registers/1,user_predef/1,scan_f/1,cafu/1,
+         receive_label/1]).
 -export([id/1]).
 
 suite() -> [{ct_hooks,[ts_install_cth]}].
@@ -46,7 +47,10 @@ groups() ->
        otp_8949_b,
        liveopt,
        coverage,
-       y_registers
+       y_registers,
+       user_predef,
+       scan_f,
+       cafu
       ]}].
 
 init_per_suite(Config) ->
@@ -376,5 +380,70 @@ do(A, B) -> {A,B}.
 appointment(#{"resolution" := Url}) ->
     do(receive _ -> Url end, #{true => Url}).
 
+%% From epp.erl.
+user_predef(_Config) ->
+    #{key:="value"} = user_predef({key,"value"}, #{}),
+    #{key:="value"} = user_predef({key,"value"}, #{key=>defined}),
+    error = user_predef({key,"value"}, #{key=>[defined]}),
+    ok.
+
+user_predef({M,Val}, Ms) ->
+    case Ms of
+	#{M:=Defs} when is_list(Defs) ->
+	    error;
+	_ ->
+	    Ms#{M=>Val}
+    end.
+
+%% From disk_log_1.erl.
+scan_f(_Config) ->
+    {1,<<>>,[]} = scan_f(<<1:32>>, 1, []),
+    {1,<<>>,[<<156>>]} = scan_f(<<1:32,156,1:32>>, 1, []),
+    ok.
+
+scan_f(<<Size:32,Tail/binary>>, FSz, Acc) when Size =< FSz ->
+    case Tail of
+        <<BinTerm:Size/binary,Tail2/binary>> ->
+            scan_f(Tail2, FSz, [BinTerm | Acc]);
+        _ ->
+            {Size,Tail,Acc}
+    end.
+
+%% From file_io_server.erl.
+cafu(_Config) ->
+    error = cafu(<<42:32>>, -1, 0, {utf32,big}),
+    error = cafu(<<42:32>>, 10, 0, {utf32,big}),
+    error = cafu(<<42:32>>, -1, 0, {utf32,little}),
+    ok.
+
+cafu(<<_/big-utf32,Rest/binary>>, N, Count, {utf32,big}) when N < 0 ->
+    cafu(Rest, -1, Count+1, {utf32,big});
+cafu(<<_/big-utf32,Rest/binary>>, N, Count, {utf32,big}) ->
+    cafu(Rest, N-1, Count+1, {utf32,big});
+cafu(<<_/little-utf32,Rest/binary>>, N, Count, {utf32,little}) when N < 0 ->
+    cafu(Rest, -1, Count+1, {utf32,little});
+cafu(_, _, _, _) ->
+    error.
+
+-record(rec_label, {bool}).
+
+receive_label(_Config) ->
+    Pid = spawn_link(fun() -> do_receive_label(#rec_label{bool=true}) end),
+    Msg = {a,b,c},
+    Pid ! {self(),Msg},
+    receive
+        {ok,Msg} ->
+            unlink(Pid),
+            exit(Pid, die),
+            ok
+    end.
+
+do_receive_label(Rec) ->
+    receive
+        {From,Message} when Rec#rec_label.bool ->
+            From ! {ok,Message},
+            do_receive_label(Rec)
+    end.
+
 %% The identity function.
 id(I) -> I.
diff --git a/lib/compiler/test/bs_match_SUITE.erl b/lib/compiler/test/bs_match_SUITE.erl
index ad48d4c0b7..e6fa80e143 100644
--- a/lib/compiler/test/bs_match_SUITE.erl
+++ b/lib/compiler/test/bs_match_SUITE.erl
@@ -39,7 +39,8 @@
 	 match_string_opt/1,select_on_integer/1,
 	 map_and_binary/1,unsafe_branch_caching/1,
 	 bad_literals/1,good_literals/1,constant_propagation/1,
-	 parse_xml/1,get_payload/1,escape/1,num_slots_different/1]).
+	 parse_xml/1,get_payload/1,escape/1,num_slots_different/1,
+         check_bitstring_list/1]).
 
 -export([coverage_id/1,coverage_external_ignore/2]).
 
@@ -71,7 +72,8 @@ groups() ->
        match_string_opt,select_on_integer,
        map_and_binary,unsafe_branch_caching,
        bad_literals,good_literals,constant_propagation,parse_xml,
-       get_payload,escape,num_slots_different]}].
+       get_payload,escape,num_slots_different,
+       check_bitstring_list]}].
 
 
 init_per_suite(Config) ->
@@ -1572,6 +1574,18 @@ lgettext(<<"de">>, <<"navigation">>, <<"Results">>) ->
 lgettext(<<"de">>, <<"navigation">>, <<"Resources">>) ->
     {ok, <<"Ressourcen">>}.
 
+%% Cover more code in beam_bsm.
+check_bitstring_list(_Config) ->
+    true = check_bitstring_list(<<1:1,0:1,1:1,1:1>>, [1,0,1,1]),
+    false = check_bitstring_list(<<1:1,0:1,1:1,1:1>>, [0]),
+    ok.
+
+check_bitstring_list(<<H:1,T1/bitstring>>, [H|T2]) ->
+    check_bitstring_list(T1, T2);
+check_bitstring_list(<<>>, []) ->
+    true;
+check_bitstring_list(_, _) ->
+    false.
 
 check(F, R) ->
     R = F().
diff --git a/lib/compiler/test/guard_SUITE.erl b/lib/compiler/test/guard_SUITE.erl
index d96cfdb7ac..7d2d58d5af 100644
--- a/lib/compiler/test/guard_SUITE.erl
+++ b/lib/compiler/test/guard_SUITE.erl
@@ -35,7 +35,8 @@
 	 basic_andalso_orelse/1,traverse_dcd/1,
 	 check_qlc_hrl/1,andalso_semi/1,t_tuple_size/1,binary_part/1,
 	 bad_constants/1,bad_guards/1,
-	 guard_in_catch/1,beam_bool_SUITE/1]).
+         guard_in_catch/1,beam_bool_SUITE/1,
+         cover_beam_dead/1]).
 
 suite() -> [{ct_hooks,[ts_install_cth]}].
 
@@ -54,7 +55,8 @@ groups() ->
        rel_ops,rel_op_combinations,
        literal_type_tests,basic_andalso_orelse,traverse_dcd,
        check_qlc_hrl,andalso_semi,t_tuple_size,binary_part,
-       bad_constants,bad_guards,guard_in_catch,beam_bool_SUITE]}].
+       bad_constants,bad_guards,guard_in_catch,beam_bool_SUITE,
+       cover_beam_dead]}].
 
 init_per_suite(Config) ->
     Config.
@@ -2202,7 +2204,31 @@ maps() ->
 evidence(#{0 := Charge}) when 0; #{[] => Charge} == #{[] => 42} ->
     ok.
 
+cover_beam_dead(_Config) ->
+    Mod = ?FUNCTION_NAME,
+    Attr = [],
+    Fs = [{function,test,1,2,
+           [{label,1},
+            {line,[]},
+            {func_info,{atom,Mod},{atom,test},1},
+            {label,2},
+            %% Cover beam_dead:turn_op/1 using swapped operand order.
+            {test,is_ne_exact,{f,3},[{integer,1},{x,0}]},
+            {test,is_eq_exact,{f,1},[{atom,a},{x,0}]},
+            {label,3},
+            {move,{atom,ok},{x,0}},
+            return]}],
+    Exp = [{test,1}],
+    Asm = {Mod,Exp,Attr,Fs,3},
+    {ok,Mod,Beam} = compile:forms(Asm, [from_asm,binary,report]),
+    {module,Mod} = code:load_binary(Mod, Mod, Beam),
+    ok = Mod:test(1),
+    ok = Mod:test(a),
+    {'EXIT',_} = (catch Mod:test(other)),
+    true = code:delete(Mod),
+    _ = code:purge(Mod),
 
+    ok.
 
 %% Call this function to turn off constant propagation.
 id(I) -> I.
diff --git a/lib/compiler/test/match_SUITE.erl b/lib/compiler/test/match_SUITE.erl
index c31695be24..35d2e8e91a 100644
--- a/lib/compiler/test/match_SUITE.erl
+++ b/lib/compiler/test/match_SUITE.erl
@@ -617,6 +617,10 @@ grab_bag(_Config) ->
 	 {bad,16#555555555555555555555555555555555555555555555555555}],
     ok = grab_bag_remove_failure(L, unit, 0),
 
+    {42,<<43,44>>} = grab_bag_single_valued(<<42,43,44>>),
+    empty_list = grab_bag_single_valued([]),
+    empty_tuple = grab_bag_single_valued({}),
+
     ok.
 
 grab_bag_remove_failure([], _Unit, _MaxFailure) ->
@@ -634,6 +638,12 @@ grab_bag_remove_failure([{stretch,_,Mi}=Stretch | Specs], Unit, _MaxFailure) ->
 	    ok
     end.
 
+%% Cover a line v3_kernel that places binary matching first.
+grab_bag_single_valued(<<H,T/bytes>>) -> {H,T};
+grab_bag_single_valued([]) -> empty_list;
+grab_bag_single_valued({}) -> empty_tuple.
+
+
 %% Regression in 19.0, reported by Alexei Sholik
 literal_binary(_Config) ->
     3 = literal_binary_match(bar, <<"y">>),