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From: Ingo Krabbe <ikrabbe.ask@web.de>
To: gcc-help@gcc.gnu.org
Subject: Re: Symbols which were not used, still in binary
Date: Thu, 29 Jun 2006 05:16:00 -0000	[thread overview]
Message-ID: <200606290716.34386.ikrabbe.ask@web.de> (raw)
In-Reply-To: <44A2F293.7353A1FF@dessent.net>

Am Mittwoch, 28. Juni 2006 23:20 schrieb Brian Dessent:
> Michael Eager wrote:
> > Arguably, the linker should know
> > that add is not referenced and could remove it, but linkers are not
> > usually able to slice and dice object files.
>
> You address this limitation by compiling with "-ffunction-sections
> -fdata-sections -Wl,--gc-sections".  However, it's still better to use
> "static" on these kinds of local functions that are only used from the
> same .o file.  This has a number of benefits:
>
> - it ensures that internal functions of a library are not exported for
> use by other code when they are not part of the defined ABI/API
> - it prevents them from taking up needless relocations, which can slow
> linking
> - when compiled -fpic (as in a shared library) it allows for direct
> calls to the function instead of having to go through the PLT which is
> slower
> - it allows the compiler freedom to inline
>

and you are warned about unused static symbols.  hmm, reminds me of cleaning 
my attic ...

> Brian

  reply	other threads:[~2006-06-29  5:16 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-06-28 19:58 Steve Kreyer
2006-06-28 20:17 ` Michael Eager
2006-06-28 21:20   ` Brian Dessent
2006-06-29  5:16     ` Ingo Krabbe [this message]
2006-06-28 20:17 ` Brian Dessent
2006-06-28 21:21   ` Steve Kreyer

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