File 2071-Don-t-crash-when-obsolete-guard-overrides-local-func.patch of Package erlang
From 8a04dd4dd2d479efe488b0bed118e10559835fb6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Thu, 11 Aug 2016 12:56:06 +0200
Subject: [PATCH 1/2] Don't crash when obsolete guard overrides local function
The compiler would crash in v3_codegen when trying to compile the
following code:
is_port(_) -> false.
foo(P) when port(P) -> ok.
We *could* have the compiler interpret the code as:
is_port(_) -> false.
foo(P) when erlang:is_port(P) -> ok.
But that would encourage using the obsolete form of the guard tests.
Note that the following code is illegal:
is_port(_) -> false.
foo(P) when is_port(P) -> ok.
It produces the following diagnostic:
call to local/imported function is_port/1 is illegal in guard
Therefore, we should refuse to compile the code.
---
lib/stdlib/src/erl_lint.erl | 28 +++++++++++++++++++++-------
lib/stdlib/test/erl_lint_SUITE.erl | 10 +++++++++-
2 files changed, 30 insertions(+), 8 deletions(-)
diff --git a/lib/stdlib/src/erl_lint.erl b/lib/stdlib/src/erl_lint.erl
index e9332ce..5ec9b90 100644
--- a/lib/stdlib/src/erl_lint.erl
+++ b/lib/stdlib/src/erl_lint.erl
@@ -238,7 +238,11 @@ format_error({removed_type, MNA, ReplacementMNA, Rel}) ->
io_lib:format("the type ~s was removed in ~s; use ~s instead",
[format_mna(MNA), Rel, format_mna(ReplacementMNA)]);
format_error({obsolete_guard, {F, A}}) ->
- io_lib:format("~p/~p obsolete", [F, A]);
+ io_lib:format("~p/~p obsolete (use is_~p/~p)", [F, A, F, A]);
+format_error({obsolete_guard_overridden,Test}) ->
+ io_lib:format("obsolete ~s/1 (meaning is_~s/1) is illegal when "
+ "there is a local/imported function named is_~p/1 ",
+ [Test,Test,Test]);
format_error({too_many_arguments,Arity}) ->
io_lib:format("too many arguments (~w) - "
"maximum allowed is ~w", [Arity,?MAX_ARGUMENTS]);
@@ -3618,16 +3622,26 @@ obsolete_guard({call,Line,{atom,Lr,F},As}, St0) ->
false ->
deprecated_function(Line, erlang, F, As, St0);
true ->
- case is_warn_enabled(obsolete_guard, St0) of
- true ->
- add_warning(Lr,{obsolete_guard, {F, Arity}}, St0);
- false ->
- St0
- end
+ St = case is_warn_enabled(obsolete_guard, St0) of
+ true ->
+ add_warning(Lr, {obsolete_guard, {F, Arity}}, St0);
+ false ->
+ St0
+ end,
+ test_overriden_by_local(Lr, F, Arity, St)
end;
obsolete_guard(_G, St) ->
St.
+test_overriden_by_local(Line, OldTest, Arity, St) ->
+ ModernTest = list_to_atom("is_"++atom_to_list(OldTest)),
+ case is_local_function(St#lint.locals, {ModernTest, Arity}) of
+ true ->
+ add_error(Line, {obsolete_guard_overridden,OldTest}, St);
+ false ->
+ St
+ end.
+
%% keyword_warning(Line, Atom, State) -> State.
%% Add warning for atoms that will be reserved keywords in the future.
%% (Currently, no such keywords to warn for.)
diff --git a/lib/stdlib/test/erl_lint_SUITE.erl b/lib/stdlib/test/erl_lint_SUITE.erl
index d916eb3..4ee3950 100644
--- a/lib/stdlib/test/erl_lint_SUITE.erl
+++ b/lib/stdlib/test/erl_lint_SUITE.erl
@@ -1554,7 +1554,15 @@ guard(Config) when is_list(Config) ->
[],
{errors,[{1,erl_lint,illegal_guard_expr},
{2,erl_lint,illegal_guard_expr}],
- []}}
+ []}},
+ {guard10,
+ <<"is_port(_) -> false.
+ t(P) when port(P) -> ok.
+ ">>,
+ [],
+ {error,
+ [{2,erl_lint,{obsolete_guard_overridden,port}}],
+ [{2,erl_lint,{obsolete_guard,{port,1}}}]}}
],
[] = run(Config, Ts1),
ok.
--
2.10.0