[erlang-bugs] Compiler crash with 'inline_list_funcs' and "fun Fun/Arity" notation

Anthony Ramine <>
Mon Jul 1 19:08:04 CEST 2013


Hello Björn,

I've amended my commit, please refetch.

Regards,

-- 
Anthony Ramine

Le 26 juin 2013 à 14:52, Anthony Ramine a écrit :

> Will amend.
> 
> -- 
> Anthony Ramine
> 
> Le 26 juin 2013 à 14:43, Björn Gustavsson a écrit :
> 
>> Thanks! Looks good. I have only two slight comments:
>> 
>> If find the first sentence in the commit message confusing:
>> 
>> "Local fun references look like plain old variables in the Core Erlang
>> AST and should not be treated as such."
>> 
>> I would suggest "but" instead of "and":
>> 
>> "Local fun references look like plain old variables in the Core Erlang
>> AST, but should not be treated as such."
>> 
>> The test cases tests that the compiler does not crash and that
>> the code can be loaded, but it does not test that the code actually
>> works. I suggest that you rewrite it to something like this:
>> 
>> ?MODULE() ->
>>    F = fun bar/1,
>>    G = lists:last([(fun (X) when F =:= X -> X end)]),
>>    F = G(F),
>>    ok.
>> 
>> bar(X) ->
>>    X.
>> 
>> /Bjorn
>> 
>> 
>> 
>> On Sat, May 18, 2013 at 6:22 PM, Anthony Ramine <> wrote:
>> Hello,
>> 
>> This patch fixes the bug by forbidding inlining of variables which values are local fun references outside of application contexts.
>> 
>>        git fetch https://github.com/nox/otp.git fix-fname-inlining
>> 
>>        https://github.com/nox/otp/compare/erlang:maint...fix-fname-inlining
>>        https://github.com/nox/otp/compare/erlang:maint...fix-fname-inlining.patch
>> 
>> Regards,
>> 
>> --
>> Anthony Ramine
>> 
>> Le 17 mai 2013 à 20:06, Anthony Ramine a écrit :
>> 
>>> Hello,
>>> 
>>> Shorter test case, showing the problem comes from the inline itself and not inline_list_funcs:
>>> 
>>> -module(test).
>>> -compile(inline).
>>> -export([foo/0]).
>>> 
>>> foo() ->
>>>   F = fun bar/1,
>>>   fun (X) when X =:= F -> X end.
>>> 
>>> bar(X) -> X.
>>> 
>>> If you run the core_lint pass, you can see where the problem comes from:
>>> 
>>> $ erlc +clint test.erl
>>> test: illegal guard expression in foo/0
>>> 
>>> The inliner inlines `when 'erlang':'=:='(X, F)` to `'erlang':'=:='(X, 'bar'/1)` but local fun references can't appear in guards.
>>> 
>>> I'll try to make a patch.
>>> 
>>> Regards,
>>> 
>>> --
>>> Anthony Ramine
>>> 
>>> Le 17 mai 2013 à 10:55, Masatake Daimon a écrit :
>>> 
>>>> Hello,
>>>> 
>>>> Compiling the following module makes the compiler crash. I'm using
>>>> R16B.
>>>> 
>>>> ===== test.erl =====
>>>> -module(test).
>>>> -compile(inline).
>>>> -compile(inline_list_funcs).
>>>> -export([foo/0]).
>>>> 
>>>> foo() ->
>>>>  lists:map(fun bar/1, [1]).
>>>> 
>>>> bar(X) -> X.
>>>> 
>>>> ===== the crash ====
>>>> % erlc test.erl
>>>> test: function '-foo/0-lists^map/1-0-'/1+15:
>>>> Internal consistency check failed - please report this bug.
>>>> Instruction: {move,{x,0},{yy,0}}
>>>> Error:       {invalid_store,{yy,0},term}:
>>>> 
>>>> 
>>>> Note that the problem disappears with any of these changes:
>>>> 
>>>> * Commenting out "-compile(inline)."
>>>> * Commenting out "-compile(inline_list_funcs)."
>>>> * Changing the definition of foo/0 to:
>>>>    foo() ->
>>>>        lists:map(fun bar/1, []).   % [] instead of [1]
>>>> * Changing the definition of foo/0 to:
>>>>    foo() ->
>>>>        lists:map(fun (A) -> bar(A) end, [1]).
>>>> 
>>>> Regards,
>>>> --
>>>> 大門 正岳 <>
>>>> _______________________________________________
>>>> erlang-bugs mailing list
>>>> 
>>>> http://erlang.org/mailman/listinfo/erlang-bugs
>>> 
>> 
>> _______________________________________________
>> erlang-bugs mailing list
>> 
>> http://erlang.org/mailman/listinfo/erlang-bugs
>> 
>> 
>> 
>> -- 
>> Björn Gustavsson, Erlang/OTP, Ericsson AB
> 



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