From mboxrd@z Thu Jan  1 00:00:00 1970
From: Karsten Blees <karsten.blees@gmail.com>
Subject: Re: What's cooking in git.git (Dec 2013, #02; Fri, 6)
Date: Wed, 18 Dec 2013 15:12:54 +0100
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References: <xmqqk3fh1qrc.fsf@gitster.dls.corp.google.com>	<52A37D70.3090400@gmail.com> <87fvq41esw.fsf@thomasrast.ch>	<52A3A1F5.3080906@gmail.com> <87lhzvhceb.fsf@linux-1gf2.Speedport_W723_V_Typ_A_1_00_098> <52A5CDB0.2020206@gmail.com>
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Cc: Junio C Hamano <gitster@pobox.com>, git@vger.kernel.org,
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Am 09.12.2013 15:03, schrieb Karsten Blees:
> 3.) Inject individual fields via macro
> 
> Instead of injecting a struct hashmap_entry, which implies alignment to sizeof(struct hashmap_entry), we could inject the individual fields, e.g.
> 
>  #define HASHMAP_ENTRY_HEADER struct hashmap_entry __next; unsinged int __hash;
> 
>  struct name_entry {
>    HASHMAP_ENTRY_HEADER
>    int namelen;
>    char *name;
>  };
> 

I've tried this as well. However, the change is much more intrusive, and produces lots of strict-aliasing warnings in GCC 4.4, probably due to this bug [1]. So I don't think its a good solution. For anyone interested, the patch can be found at [2].

[1] http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42032
[2] https://github.com/kblees/git/commits/kb/hashmap-v5-fixes-macro