[erlang-bugs] mnesia/dets breakage when otp R15B03-1 is compiled by gcc 4.8 or 4.9

[Sverker Eriksson]

This commit seems like yet a bug fix for the this fix.

c4da6eed78d30670d3602f746030e03c46137ead
Fix EV_* macros and functions signedness flaws

/Sverker, Erlang/OTP


On 12/05/2013 12:54 PM, Mikael Pettersson wrote:
> Lukas Larsson writes:
>   > Hello,
>   >
>   > Could it be OTP-11246? It is the only gcc version related patch that I
>   > can think of.
>
> Both test cases, mine and Erik's, are fixed by backporting two commits,
>
> >From 9f3dc09c1a70bd485b211768bedf989bed7fbf21 Mon Sep 17 00:00:00 2001
> From: Lukas Larsson <lukas@REDACTED>
> Date: Mon, 12 Aug 2013 16:04:31 +0200
> Subject: [PATCH] erts: Refactor non-pure macros to functions
>
> and
>
> >From 3b1d9f46c187ecdad3930c52fa4fbe4d547277c8 Mon Sep 17 00:00:00 2001
> From: Lukas Larsson <lukas@REDACTED>
> Date: Tue, 20 Aug 2013 17:19:36 +0200
> Subject: [PATCH] erts: Fix bug in translating ev macros to functions
>
> The first one suffices for the test cases, but the second one fixes
> apparent errors in the first one so I'll treat them as a unit.
>
> I'll run some more tests on our full code base.
>
> /Mikael
>
>   >
>   > Lukas
>   >
>   > On 04/12/13 15:00, Mikael Pettersson wrote:
>   > > We're using otp R15B03-1 on x86_64-linux.  During initialization of our
>   > > application we create a bunch of mnesia disc_copies tables.  If otp
>   > > was compiled by gcc 4.8 or 4.9, then during the creation of the 257th
>   > > mnesia table DETS spews the following warning
>   > >
>   > > dets: file "/.../Mnesia.nonode@REDACTED/schema.DAT" not properly closed, repairing ...
>   > >
>   > > but the mnesia:create_table/2 call doesn't fail.  However the schema.DAT
>   > > file is corrupt and subsequent usage of mnesia fails.
>   > >
>   > > If otp R15B03-1 is compiled with gcc 4.7 or 4.6 the problem doesn't occur.
>   > >
>   > > If we use otp R16B02 compiled by gcc 4.8 or 4.9 the problem doesn't occur.
>   > >
>   > > At the moment we can't upgrade to R16B02, and as our developers upgrade their
>   > > machines to newer Linux distributions they get gcc-4.8 as their system compiler
>   > > and things break.
>   > >
>   > > Are there any known bug fixes in R16 that may be related to this?
>   > >
>   > > I'm appending the trivial reproducer below.
>   > >
>   > > /Mikael
>   > >
>   > > -module(bug).
>   > > -compile(export_all).
>   > > doit() ->
>   > >      mnesia:delete_schema([node()]),
>   > >      mnesia:create_schema([node()]),
>   > >      mnesia:start(),
>   > >      doit(0).
>   > >
>   > > doit(I) when I < 260 ->
>   > >      D0 = $0 + (I rem 10),
>   > >      D1 = $0 + ((I div 10) rem 10),
>   > >      D2 = $0 + ((I div 100) rem 10),
>   > >      Name = list_to_atom([$f, $o, $o, D2, D1, D0]),
>   > >      io:format("creating table ~p~n", [Name]),
>   > >      TabDef = [{disc_copies,[node()]}, {type,set}, {attributes,[key,val]}],
>   > >      {atomic, ok} = mnesia:create_table(Name, TabDef),
>   > >      doit(I + 1);
>   > > doit(_I) ->
>   > >      ok.
>   > > _______________________________________________
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>   > >
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