File 0362-dialyzer-Refine-the-test-for-overspecified-functions.patch of Package erlang
From 324fc38bc442460f871f3ae002dd853415ae9e51 Mon Sep 17 00:00:00 2001
From: Hans Bolinder <hasse@erlang.org>
Date: Thu, 24 May 2018 12:21:21 +0200
Subject: [PATCH 1/6] dialyzer: Refine the test for overspecified functions
The -Woverspecs (-Wspecdiffs) option generates warnings in a few more
cases. The refinement is analogous to the test that -Wunderspecs
already does: it checks if the contract has nothing in common with
some element (see erl_types:t_elements/1) of the success typing.
---
lib/dialyzer/src/dialyzer.erl | 4 +
lib/dialyzer/src/dialyzer_contracts.erl | 99 ++++++++++++++-----
lib/typer/src/typer.erl | 2 +-
.../overspecs_SUITE_data/dialyzer_options | 1 +
.../test/overspecs_SUITE_data/results/iodata | 2 +
.../test/overspecs_SUITE_data/results/iolist | 2 +
.../test/overspecs_SUITE_data/src/iodata.erl | 41 ++++++++
.../test/overspecs_SUITE_data/src/iolist.erl | 41 ++++++++
.../specdiffs_SUITE_data/dialyzer_options | 1 +
.../test/specdiffs_SUITE_data/results/iodata | 3 +
.../test/specdiffs_SUITE_data/results/iolist | 2 +
.../test/specdiffs_SUITE_data/src/iodata.erl | 41 ++++++++
.../test/specdiffs_SUITE_data/src/iolist.erl | 41 ++++++++
13 files changed, 255 insertions(+), 25 deletions(-)
create mode 100644 lib/dialyzer/test/overspecs_SUITE_data/dialyzer_options
create mode 100644 lib/dialyzer/test/overspecs_SUITE_data/results/iodata
create mode 100644 lib/dialyzer/test/overspecs_SUITE_data/results/iolist
create mode 100644 lib/dialyzer/test/overspecs_SUITE_data/src/iodata.erl
create mode 100644 lib/dialyzer/test/overspecs_SUITE_data/src/iolist.erl
create mode 100644 lib/dialyzer/test/specdiffs_SUITE_data/dialyzer_options
create mode 100644 lib/dialyzer/test/specdiffs_SUITE_data/results/iodata
create mode 100644 lib/dialyzer/test/specdiffs_SUITE_data/results/iolist
create mode 100644 lib/dialyzer/test/specdiffs_SUITE_data/src/iodata.erl
create mode 100644 lib/dialyzer/test/specdiffs_SUITE_data/src/iolist.erl
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
@@ -415,6 +415,10 @@ message_to_string({extra_range, [M, F, A, ExtraRanges, SigRange]}) ->
io_lib:format("The specification for ~w:~w/~w states that the function"
" might also return ~s but the inferred return is ~s\n",
[M, F, A, ExtraRanges, SigRange]);
+message_to_string({missing_range, [M, F, A, ExtraRanges, ContrRange]}) ->
+ io_lib:format("The success typing for ~w:~w/~w implies that the function"
+ " might also return ~s but the specification return is ~s\n",
+ [M, F, A, ExtraRanges, ContrRange]);
message_to_string({overlapping_contract, [M, F, A]}) ->
io_lib:format("Overloaded contract for ~w:~w/~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;
@@ -210,11 +212,26 @@ check_contracts(Contracts, Callgraph, FunTypes, ModOpaques) ->
end,
dict:fold(FoldFun, [], 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()) ->
+ 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 = ~p\nSR = ~p\n", [CRngs, STRng]),
+ ?debug("\nCR = ~s\nSR = ~s\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/typer/src/typer.erl b/lib/typer/src/typer.erl
index 9d3d9ce438..4b99f5f72e 100644
--- a/lib/typer/src/typer.erl
+++ b/lib/typer/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/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.
--
2.17.1
