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-rw-r--r--lib/dialyzer/src/dialyzer.erl4
-rw-r--r--lib/dialyzer/src/dialyzer_contracts.erl99
-rw-r--r--lib/dialyzer/src/dialyzer_dataflow.erl44
-rw-r--r--lib/dialyzer/src/typer.erl2
-rw-r--r--lib/dialyzer/test/overspecs_SUITE_data/dialyzer_options1
-rw-r--r--lib/dialyzer/test/overspecs_SUITE_data/results/iodata2
-rw-r--r--lib/dialyzer/test/overspecs_SUITE_data/results/iolist2
-rw-r--r--lib/dialyzer/test/overspecs_SUITE_data/src/iodata.erl41
-rw-r--r--lib/dialyzer/test/overspecs_SUITE_data/src/iolist.erl41
-rw-r--r--lib/dialyzer/test/small_SUITE_data/results/unused_funs5
-rw-r--r--lib/dialyzer/test/small_SUITE_data/src/unused_funs.erl21
-rw-r--r--lib/dialyzer/test/specdiffs_SUITE_data/dialyzer_options1
-rw-r--r--lib/dialyzer/test/specdiffs_SUITE_data/results/iodata3
-rw-r--r--lib/dialyzer/test/specdiffs_SUITE_data/results/iolist2
-rw-r--r--lib/dialyzer/test/specdiffs_SUITE_data/src/iodata.erl41
-rw-r--r--lib/dialyzer/test/specdiffs_SUITE_data/src/iolist.erl41
16 files changed, 315 insertions, 35 deletions
diff --git a/lib/dialyzer/src/dialyzer.erl b/lib/dialyzer/src/dialyzer.erl
index 1538174d4a..185c8c9ae6 100644
--- a/lib/dialyzer/src/dialyzer.erl
+++ b/lib/dialyzer/src/dialyzer.erl
@@ -409,6 +409,10 @@ message_to_string({extra_range, [M, F, A, ExtraRanges, SigRange]}) ->
io_lib:format("The specification for ~w:~tw/~w states that the function"
" might also return ~ts but the inferred return is ~ts\n",
[M, F, A, ExtraRanges, SigRange]);
+message_to_string({missing_range, [M, F, A, ExtraRanges, ContrRange]}) ->
+ io_lib:format("The success typing for ~w:~tw/~w implies that the function"
+ " might also return ~ts but the specification return is ~ts\n",
+ [M, F, A, ExtraRanges, ContrRange]);
message_to_string({overlapping_contract, [M, F, A]}) ->
io_lib:format("Overloaded contract for ~w:~tw/~w has overlapping domains;"
" such contracts are currently unsupported and are simply ignored\n",
diff --git a/lib/dialyzer/src/dialyzer_contracts.erl b/lib/dialyzer/src/dialyzer_contracts.erl
index 0df15e55f9..af7f4385ad 100644
--- a/lib/dialyzer/src/dialyzer_contracts.erl
+++ b/lib/dialyzer/src/dialyzer_contracts.erl
@@ -197,9 +197,11 @@ check_contracts(Contracts, Callgraph, FunTypes, ModOpaques) ->
false ->
[{MFA, Contract}|NewContracts]
end;
- {error, {extra_range, _, _}} ->
- %% do not treat extra range as an error in this check
- %% since that prevents discovering other actual errors
+ {range_warnings, _} ->
+ %% do not treat extra range, either in contract or
+ %% in success typing, as an error in this check
+ %% since that prevents discovering other actual
+ %% errors
[{MFA, Contract}|NewContracts];
{error, _Error} -> NewContracts
end;
@@ -210,14 +212,26 @@ check_contracts(Contracts, Callgraph, FunTypes, ModOpaques) ->
end,
orddict:from_list(lists:foldl(FoldFun, [], orddict:to_list(FunTypes))).
+-type check_contract_return() ::
+ 'ok'
+ | {'error',
+ 'invalid_contract'
+ | {'opaque_mismatch', erl_types:erl_type()}
+ | {'overlapping_contract', [module() | atom() | byte()]}
+ | string()}
+ | {'range_warnings',
+ [{'error', {'extra_range' | 'missing_range',
+ erl_types:erl_type(),
+ erl_types:erl_type()}}]}.
+
%% Checks all components of a contract
--spec check_contract(#contract{}, erl_types:erl_type()) -> 'ok' | {'error', term()}.
+-spec check_contract(#contract{}, erl_types:erl_type()) -> check_contract_return().
check_contract(Contract, SuccType) ->
check_contract(Contract, SuccType, 'universe').
-spec check_contract(#contract{}, erl_types:erl_type(), erl_types:opaques()) ->
- 'ok' | {'error', term()}.
+ check_contract_return().
check_contract(#contract{contracts = Contracts}, SuccType, Opaques) ->
try
@@ -290,15 +304,23 @@ check_contract_inf_list([], _SuccType, _Opaques, OM) ->
check_extraneous([], _SuccType) -> ok;
check_extraneous([C|Cs], SuccType) ->
case check_extraneous_1(C, SuccType) of
- ok -> check_extraneous(Cs, SuccType);
- Error -> Error
+ {error, invalid_contract} = Error ->
+ Error;
+ {error, {extra_range, _, _}} = Error ->
+ {range_warnings, [Error | check_missing(C, SuccType)]};
+ ok ->
+ case check_missing(C, SuccType) of
+ [] -> check_extraneous(Cs, SuccType);
+ ErrorL -> {range_warnings, ErrorL}
+ end
end.
check_extraneous_1(Contract, SuccType) ->
CRng = erl_types:t_fun_range(Contract),
CRngs = erl_types:t_elements(CRng),
STRng = erl_types:t_fun_range(SuccType),
- ?debug("CR = ~tp\nSR = ~tp\n", [CRngs, STRng]),
+ ?debug("\nCR = ~ts\nSR = ~ts\n", [erl_types:t_to_string(CRng),
+ erl_types:t_to_string(STRng)]),
case [CR || CR <- CRngs,
erl_types:t_is_none(erl_types:t_inf(CR, STRng))] of
[] ->
@@ -341,6 +363,18 @@ map_part(Type) ->
is_empty_map(Type) ->
erl_types:t_is_equal(Type, erl_types:t_from_term(#{})).
+check_missing(Contract, SuccType) ->
+ CRng = erl_types:t_fun_range(Contract),
+ STRng = erl_types:t_fun_range(SuccType),
+ STRngs = erl_types:t_elements(STRng),
+ ?debug("\nCR = ~ts\nSR = ~ts\n", [erl_types:t_to_string(CRng),
+ erl_types:t_to_string(STRng)]),
+ case [STR || STR <- STRngs,
+ erl_types:t_is_none(erl_types:t_inf(STR, CRng))] of
+ [] -> [];
+ STRs -> [{error, {missing_range, erl_types:t_sup(STRs), CRng}}]
+ end.
+
%% This is the heart of the "range function"
-spec process_contracts([contract_pair()], [erl_types:erl_type()]) ->
erl_types:erl_type().
@@ -712,22 +746,30 @@ get_invalid_contract_warnings_funs([{MFA, {FileLine, Contract, _Xtra}}|Left],
[W|Acc];
{error, {overlapping_contract, []}} ->
[overlapping_contract_warning(MFA, WarningInfo)|Acc];
- {error, {extra_range, ExtraRanges, STRange}} ->
- Warn =
- case t_from_forms_without_remote(Contract#contract.forms,
- MFA, RecDict) of
- {ok, NoRemoteType} ->
- CRet = erl_types:t_fun_range(NoRemoteType),
- erl_types:t_is_subtype(ExtraRanges, CRet);
- unsupported ->
- true
- end,
- case Warn of
- true ->
- [extra_range_warning(MFA, WarningInfo, ExtraRanges, STRange)|Acc];
- false ->
- Acc
- end;
+ {range_warnings, Errors} ->
+ Fun =
+ fun({error, {extra_range, ExtraRanges, STRange}}, Acc0) ->
+ Warn =
+ case t_from_forms_without_remote(Contract#contract.forms,
+ MFA, RecDict) of
+ {ok, NoRemoteType} ->
+ CRet = erl_types:t_fun_range(NoRemoteType),
+ erl_types:t_is_subtype(ExtraRanges, CRet);
+ unsupported ->
+ true
+ end,
+ case Warn of
+ true ->
+ [extra_range_warning(MFA, WarningInfo,
+ ExtraRanges, STRange)|Acc0];
+ false ->
+ Acc0
+ end;
+ ({error, {missing_range, ExtraRanges, CRange}}, Acc0) ->
+ [missing_range_warning(MFA, WarningInfo,
+ ExtraRanges, CRange)|Acc0]
+ end,
+ lists:foldl(Fun, Acc, Errors);
{error, Msg} ->
[{?WARN_CONTRACT_SYNTAX, WarningInfo, Msg}|Acc];
ok ->
@@ -745,6 +787,9 @@ get_invalid_contract_warnings_funs([{MFA, {FileLine, Contract, _Xtra}}|Left],
{error, _} ->
[invalid_contract_warning(MFA, WarningInfo, BifSig, RecDict)
|Acc];
+ {range_warnings, _} ->
+ picky_contract_check(CSig, BifSig, MFA, WarningInfo,
+ Contract, RecDict, Acc);
ok ->
picky_contract_check(CSig, BifSig, MFA, WarningInfo,
Contract, RecDict, Acc)
@@ -778,6 +823,12 @@ extra_range_warning({M, F, A}, WarningInfo, ExtraRanges, STRange) ->
{?WARN_CONTRACT_SUPERTYPE, WarningInfo,
{extra_range, [M, F, A, ERangesStr, STRangeStr]}}.
+missing_range_warning({M, F, A}, WarningInfo, ExtraRanges, CRange) ->
+ ERangesStr = erl_types:t_to_string(ExtraRanges),
+ CRangeStr = erl_types:t_to_string(CRange),
+ {?WARN_CONTRACT_SUBTYPE, WarningInfo,
+ {missing_range, [M, F, A, ERangesStr, CRangeStr]}}.
+
picky_contract_check(CSig0, Sig0, MFA, WarningInfo, Contract, RecDict, Acc) ->
CSig = erl_types:t_abstract_records(CSig0, RecDict),
Sig = erl_types:t_abstract_records(Sig0, RecDict),
diff --git a/lib/dialyzer/src/dialyzer_dataflow.erl b/lib/dialyzer/src/dialyzer_dataflow.erl
index c5f93a3392..45b4abb253 100644
--- a/lib/dialyzer/src/dialyzer_dataflow.erl
+++ b/lib/dialyzer/src/dialyzer_dataflow.erl
@@ -102,6 +102,8 @@
| 'undefined', % race
fun_homes :: dict:dict(label(), mfa())
| 'undefined', % race
+ reachable_funs :: sets:set(label())
+ | 'undefined', % race
plt :: dialyzer_plt:plt()
| 'undefined', % race
opaques :: [type()]
@@ -269,9 +271,11 @@ traverse(Tree, Map, State) ->
case state__warning_mode(State) of
true -> {State, Map, Type};
false ->
- State2 = state__add_work(get_label(Tree), State),
+ FunLbl = get_label(Tree),
+ State2 = state__add_work(FunLbl, State),
State3 = state__update_fun_env(Tree, Map, State2),
- {State3, Map, Type}
+ State4 = state__add_reachable(FunLbl, State3),
+ {State4, Map, Type}
end;
'let' ->
handle_let(Tree, Map, State);
@@ -3039,25 +3043,35 @@ state__new(Callgraph, Codeserver, Tree, Plt, Module, Records) ->
{TreeMap, FunHomes} = build_tree_map(Tree, Callgraph),
Funs = dict:fetch_keys(TreeMap),
FunTab = init_fun_tab(Funs, dict:new(), TreeMap, Callgraph, Plt),
- ExportedFuns =
- [Fun || Fun <- Funs--[top], dialyzer_callgraph:is_escaping(Fun, Callgraph)],
- Work = init_work(ExportedFuns),
+ ExportedFunctions =
+ [Fun ||
+ Fun <- Funs--[top],
+ dialyzer_callgraph:is_escaping(Fun, Callgraph),
+ dialyzer_callgraph:lookup_name(Fun, Callgraph) =/= error
+ ],
+ Work = init_work(ExportedFunctions),
Env = lists:foldl(fun(Fun, Env) -> dict:store(Fun, map__new(), Env) end,
dict:new(), Funs),
#state{callgraph = Callgraph, codeserver = Codeserver,
envs = Env, fun_tab = FunTab, fun_homes = FunHomes, opaques = Opaques,
plt = Plt, races = dialyzer_races:new(), records = Records,
warning_mode = false, warnings = [], work = Work, tree_map = TreeMap,
- module = Module}.
+ module = Module, reachable_funs = sets:new()}.
state__warning_mode(#state{warning_mode = WM}) ->
WM.
state__set_warning_mode(#state{tree_map = TreeMap, fun_tab = FunTab,
- races = Races} = State) ->
+ races = Races, callgraph = Callgraph,
+ reachable_funs = ReachableFuns} = State) ->
?debug("==========\nStarting warning pass\n==========\n", []),
Funs = dict:fetch_keys(TreeMap),
- State#state{work = init_work([top|Funs--[top]]),
+ Work =
+ [Fun ||
+ Fun <- Funs--[top],
+ dialyzer_callgraph:lookup_name(Fun, Callgraph) =/= error orelse
+ sets:is_element(Fun, ReachableFuns)],
+ State#state{work = init_work(Work),
fun_tab = FunTab, warning_mode = true,
races = dialyzer_races:put_race_analysis(true, Races)}.
@@ -3149,7 +3163,8 @@ state__get_race_warnings(#state{races = Races} = State) ->
State1#state{races = Races1}.
state__get_warnings(#state{tree_map = TreeMap, fun_tab = FunTab,
- callgraph = Callgraph, plt = Plt} = State) ->
+ callgraph = Callgraph, plt = Plt,
+ reachable_funs = ReachableFuns} = State) ->
FoldFun =
fun({top, _}, AccState) -> AccState;
({FunLbl, Fun}, AccState) ->
@@ -3184,7 +3199,12 @@ state__get_warnings(#state{tree_map = TreeMap, fun_tab = FunTab,
GenRet = dialyzer_contracts:get_contract_return(C),
not t_is_unit(GenRet)
end,
- case Warn of
+ %% Do not output warnings for unreachable funs.
+ case
+ Warn andalso
+ (dialyzer_callgraph:lookup_name(FunLbl, Callgraph) =/= error
+ orelse sets:is_element(FunLbl, ReachableFuns))
+ of
true ->
case classify_returns(Fun) of
no_match ->
@@ -3255,6 +3275,10 @@ state__get_args_and_status(Tree, #state{fun_tab = FunTab}) ->
{ok, {ArgTypes, _}} -> {ArgTypes, true}
end.
+state__add_reachable(FunLbl, #state{reachable_funs = ReachableFuns}=State) ->
+ NewReachableFuns = sets:add_element(FunLbl, ReachableFuns),
+ State#state{reachable_funs = NewReachableFuns}.
+
build_tree_map(Tree, Callgraph) ->
Fun =
fun(T, {Dict, Homes, FunLbls} = Acc) ->
diff --git a/lib/dialyzer/src/typer.erl b/lib/dialyzer/src/typer.erl
index 9d3d9ce438..4b99f5f72e 100644
--- a/lib/dialyzer/src/typer.erl
+++ b/lib/dialyzer/src/typer.erl
@@ -401,7 +401,7 @@ get_type({{M, F, A} = MFA, Range, Arg}, CodeServer, Records) ->
Sig = erl_types:t_fun(Arg, Range),
case dialyzer_contracts:check_contract(Contract, Sig) of
ok -> {{F, A}, {contract, Contract}};
- {error, {extra_range, _, _}} ->
+ {range_warnings, _} ->
{{F, A}, {contract, Contract}};
{error, {overlapping_contract, []}} ->
{{F, A}, {contract, Contract}};
diff --git a/lib/dialyzer/test/overspecs_SUITE_data/dialyzer_options b/lib/dialyzer/test/overspecs_SUITE_data/dialyzer_options
new file mode 100644
index 0000000000..ff4517e59d
--- /dev/null
+++ b/lib/dialyzer/test/overspecs_SUITE_data/dialyzer_options
@@ -0,0 +1 @@
+{dialyzer_options, [{warnings, [overspecs]}]}.
diff --git a/lib/dialyzer/test/overspecs_SUITE_data/results/iodata b/lib/dialyzer/test/overspecs_SUITE_data/results/iodata
new file mode 100644
index 0000000000..d9c70330ec
--- /dev/null
+++ b/lib/dialyzer/test/overspecs_SUITE_data/results/iodata
@@ -0,0 +1,2 @@
+
+iodata.erl:7: The success typing for iodata:encode/2 implies that the function might also return integer() but the specification return is binary() | maybe_improper_list(binary() | maybe_improper_list(any(),binary() | []) | byte(),binary() | [])
diff --git a/lib/dialyzer/test/overspecs_SUITE_data/results/iolist b/lib/dialyzer/test/overspecs_SUITE_data/results/iolist
new file mode 100644
index 0000000000..ca556f017c
--- /dev/null
+++ b/lib/dialyzer/test/overspecs_SUITE_data/results/iolist
@@ -0,0 +1,2 @@
+
+iolist.erl:7: The success typing for iolist:encode/2 implies that the function might also return integer() but the specification return is maybe_improper_list(binary() | maybe_improper_list(any(),binary() | []) | byte(),binary() | [])
diff --git a/lib/dialyzer/test/overspecs_SUITE_data/src/iodata.erl b/lib/dialyzer/test/overspecs_SUITE_data/src/iodata.erl
new file mode 100644
index 0000000000..caa44f6c91
--- /dev/null
+++ b/lib/dialyzer/test/overspecs_SUITE_data/src/iodata.erl
@@ -0,0 +1,41 @@
+-module(iodata).
+
+%% A small part of beam_asm.
+
+-export([encode/2]).
+
+-spec encode(non_neg_integer(), integer()) -> iodata(). % extra range binary()
+
+encode(Tag, N) when Tag >= 0, N < 0 ->
+ encode1(Tag, negative_to_bytes(N));
+encode(Tag, N) when Tag >= 0, N < 16 ->
+ (N bsl 4) bor Tag; % not in the specification
+encode(Tag, N) when Tag >= 0, N < 16#800 ->
+ [((N bsr 3) band 2#11100000) bor Tag bor 2#00001000, N band 16#ff];
+encode(Tag, N) when Tag >= 0 ->
+ encode1(Tag, to_bytes(N)).
+
+encode1(Tag, Bytes) ->
+ case iolist_size(Bytes) of
+ Num when 2 =< Num, Num =< 8 ->
+ [((Num-2) bsl 5) bor 2#00011000 bor Tag| Bytes];
+ Num when 8 < Num ->
+ [2#11111000 bor Tag, encode(0, Num-9)| Bytes]
+ end.
+
+to_bytes(N) ->
+ Bin = binary:encode_unsigned(N),
+ case Bin of
+ <<0:1,_/bits>> -> Bin;
+ <<1:1,_/bits>> -> [0,Bin]
+ end.
+
+negative_to_bytes(N) when N >= -16#8000 ->
+ <<N:16>>;
+negative_to_bytes(N) ->
+ Bytes = byte_size(binary:encode_unsigned(-N)),
+ Bin = <<N:Bytes/unit:8>>,
+ case Bin of
+ <<0:1,_/bits>> -> [16#ff,Bin];
+ <<1:1,_/bits>> -> Bin
+ end.
diff --git a/lib/dialyzer/test/overspecs_SUITE_data/src/iolist.erl b/lib/dialyzer/test/overspecs_SUITE_data/src/iolist.erl
new file mode 100644
index 0000000000..7cceeda24e
--- /dev/null
+++ b/lib/dialyzer/test/overspecs_SUITE_data/src/iolist.erl
@@ -0,0 +1,41 @@
+-module(iolist).
+
+%% A small part of beam_asm.
+
+-export([encode/2]).
+
+-spec encode(non_neg_integer(), integer()) -> iolist().
+
+encode(Tag, N) when Tag >= 0, N < 0 ->
+ encode1(Tag, negative_to_bytes(N));
+encode(Tag, N) when Tag >= 0, N < 16 ->
+ (N bsl 4) bor Tag; % not in the specification
+encode(Tag, N) when Tag >= 0, N < 16#800 ->
+ [((N bsr 3) band 2#11100000) bor Tag bor 2#00001000, N band 16#ff];
+encode(Tag, N) when Tag >= 0 ->
+ encode1(Tag, to_bytes(N)).
+
+encode1(Tag, Bytes) ->
+ case iolist_size(Bytes) of
+ Num when 2 =< Num, Num =< 8 ->
+ [((Num-2) bsl 5) bor 2#00011000 bor Tag| Bytes];
+ Num when 8 < Num ->
+ [2#11111000 bor Tag, encode(0, Num-9)| Bytes]
+ end.
+
+to_bytes(N) ->
+ Bin = binary:encode_unsigned(N),
+ case Bin of
+ <<0:1,_/bits>> -> Bin;
+ <<1:1,_/bits>> -> [0,Bin]
+ end.
+
+negative_to_bytes(N) when N >= -16#8000 ->
+ <<N:16>>;
+negative_to_bytes(N) ->
+ Bytes = byte_size(binary:encode_unsigned(-N)),
+ Bin = <<N:Bytes/unit:8>>,
+ case Bin of
+ <<0:1,_/bits>> -> [16#ff,Bin];
+ <<1:1,_/bits>> -> Bin
+ end.
diff --git a/lib/dialyzer/test/small_SUITE_data/results/unused_funs b/lib/dialyzer/test/small_SUITE_data/results/unused_funs
new file mode 100644
index 0000000000..c468457ead
--- /dev/null
+++ b/lib/dialyzer/test/small_SUITE_data/results/unused_funs
@@ -0,0 +1,5 @@
+
+unused_funs.erl:10: The pattern 'error' can never match the type 'other_error'
+unused_funs.erl:15: Function not_used/0 will never be called
+unused_funs.erl:19: Function foo/1 will never be called
+unused_funs.erl:7: Function test/0 has no local return
diff --git a/lib/dialyzer/test/small_SUITE_data/src/unused_funs.erl b/lib/dialyzer/test/small_SUITE_data/src/unused_funs.erl
new file mode 100644
index 0000000000..c24cf3ea81
--- /dev/null
+++ b/lib/dialyzer/test/small_SUITE_data/src/unused_funs.erl
@@ -0,0 +1,21 @@
+%% See also ERL-593.
+
+-module(unused_funs).
+
+-export([test/0]).
+
+test() -> % "has no local return"
+ Var = outer_scope,
+ case other_error of
+ error -> % "can never match"
+ %% No warnings "no local return" and "_ = 1 can never match 0" (!)
+ foo(fun() -> {Var, 1 = 0} end)
+ end.
+
+not_used() -> % "will never be called"
+ %% No warnings "no local return" and "1 can never match 0".
+ foo(fun() -> 1 = 0 end).
+
+foo(Fun) -> % "will never be called"
+ 1 = 0, % No pattern match warning (foo/1 is not traversed at all).
+ Fun().
diff --git a/lib/dialyzer/test/specdiffs_SUITE_data/dialyzer_options b/lib/dialyzer/test/specdiffs_SUITE_data/dialyzer_options
new file mode 100644
index 0000000000..56b36f2ed4
--- /dev/null
+++ b/lib/dialyzer/test/specdiffs_SUITE_data/dialyzer_options
@@ -0,0 +1 @@
+{dialyzer_options, [{warnings, [specdiffs]}]}.
diff --git a/lib/dialyzer/test/specdiffs_SUITE_data/results/iodata b/lib/dialyzer/test/specdiffs_SUITE_data/results/iodata
new file mode 100644
index 0000000000..3fb12fe000
--- /dev/null
+++ b/lib/dialyzer/test/specdiffs_SUITE_data/results/iodata
@@ -0,0 +1,3 @@
+
+iodata.erl:7: The specification for iodata:encode/2 states that the function might also return binary() but the inferred return is nonempty_maybe_improper_list(<<_:8,_:_*8>> | nonempty_maybe_improper_list(<<_:8,_:_*8>> | nonempty_maybe_improper_list(any(),<<_:8,_:_*8>> | []) | byte(),<<_:8,_:_*8>> | []) | integer(),<<_:8,_:_*8>> | []) | integer()
+iodata.erl:7: The success typing for iodata:encode/2 implies that the function might also return integer() but the specification return is binary() | maybe_improper_list(binary() | maybe_improper_list(any(),binary() | []) | byte(),binary() | [])
diff --git a/lib/dialyzer/test/specdiffs_SUITE_data/results/iolist b/lib/dialyzer/test/specdiffs_SUITE_data/results/iolist
new file mode 100644
index 0000000000..ca556f017c
--- /dev/null
+++ b/lib/dialyzer/test/specdiffs_SUITE_data/results/iolist
@@ -0,0 +1,2 @@
+
+iolist.erl:7: The success typing for iolist:encode/2 implies that the function might also return integer() but the specification return is maybe_improper_list(binary() | maybe_improper_list(any(),binary() | []) | byte(),binary() | [])
diff --git a/lib/dialyzer/test/specdiffs_SUITE_data/src/iodata.erl b/lib/dialyzer/test/specdiffs_SUITE_data/src/iodata.erl
new file mode 100644
index 0000000000..caa44f6c91
--- /dev/null
+++ b/lib/dialyzer/test/specdiffs_SUITE_data/src/iodata.erl
@@ -0,0 +1,41 @@
+-module(iodata).
+
+%% A small part of beam_asm.
+
+-export([encode/2]).
+
+-spec encode(non_neg_integer(), integer()) -> iodata(). % extra range binary()
+
+encode(Tag, N) when Tag >= 0, N < 0 ->
+ encode1(Tag, negative_to_bytes(N));
+encode(Tag, N) when Tag >= 0, N < 16 ->
+ (N bsl 4) bor Tag; % not in the specification
+encode(Tag, N) when Tag >= 0, N < 16#800 ->
+ [((N bsr 3) band 2#11100000) bor Tag bor 2#00001000, N band 16#ff];
+encode(Tag, N) when Tag >= 0 ->
+ encode1(Tag, to_bytes(N)).
+
+encode1(Tag, Bytes) ->
+ case iolist_size(Bytes) of
+ Num when 2 =< Num, Num =< 8 ->
+ [((Num-2) bsl 5) bor 2#00011000 bor Tag| Bytes];
+ Num when 8 < Num ->
+ [2#11111000 bor Tag, encode(0, Num-9)| Bytes]
+ end.
+
+to_bytes(N) ->
+ Bin = binary:encode_unsigned(N),
+ case Bin of
+ <<0:1,_/bits>> -> Bin;
+ <<1:1,_/bits>> -> [0,Bin]
+ end.
+
+negative_to_bytes(N) when N >= -16#8000 ->
+ <<N:16>>;
+negative_to_bytes(N) ->
+ Bytes = byte_size(binary:encode_unsigned(-N)),
+ Bin = <<N:Bytes/unit:8>>,
+ case Bin of
+ <<0:1,_/bits>> -> [16#ff,Bin];
+ <<1:1,_/bits>> -> Bin
+ end.
diff --git a/lib/dialyzer/test/specdiffs_SUITE_data/src/iolist.erl b/lib/dialyzer/test/specdiffs_SUITE_data/src/iolist.erl
new file mode 100644
index 0000000000..7cceeda24e
--- /dev/null
+++ b/lib/dialyzer/test/specdiffs_SUITE_data/src/iolist.erl
@@ -0,0 +1,41 @@
+-module(iolist).
+
+%% A small part of beam_asm.
+
+-export([encode/2]).
+
+-spec encode(non_neg_integer(), integer()) -> iolist().
+
+encode(Tag, N) when Tag >= 0, N < 0 ->
+ encode1(Tag, negative_to_bytes(N));
+encode(Tag, N) when Tag >= 0, N < 16 ->
+ (N bsl 4) bor Tag; % not in the specification
+encode(Tag, N) when Tag >= 0, N < 16#800 ->
+ [((N bsr 3) band 2#11100000) bor Tag bor 2#00001000, N band 16#ff];
+encode(Tag, N) when Tag >= 0 ->
+ encode1(Tag, to_bytes(N)).
+
+encode1(Tag, Bytes) ->
+ case iolist_size(Bytes) of
+ Num when 2 =< Num, Num =< 8 ->
+ [((Num-2) bsl 5) bor 2#00011000 bor Tag| Bytes];
+ Num when 8 < Num ->
+ [2#11111000 bor Tag, encode(0, Num-9)| Bytes]
+ end.
+
+to_bytes(N) ->
+ Bin = binary:encode_unsigned(N),
+ case Bin of
+ <<0:1,_/bits>> -> Bin;
+ <<1:1,_/bits>> -> [0,Bin]
+ end.
+
+negative_to_bytes(N) when N >= -16#8000 ->
+ <<N:16>>;
+negative_to_bytes(N) ->
+ Bytes = byte_size(binary:encode_unsigned(-N)),
+ Bin = <<N:Bytes/unit:8>>,
+ case Bin of
+ <<0:1,_/bits>> -> [16#ff,Bin];
+ <<1:1,_/bits>> -> Bin
+ end.
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-02 19:27:04 +0000