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List:       binutils
Subject:    Re: [RFC] Move static archive dependencies into ld
From:       Howard Chu <hyc () symas ! com>
Date:       2023-06-05 14:16:29
Message-ID: 4b99cb5f-79a9-0a86-f675-81e4fa77e1b8 () symas ! com
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What needs to happen to move this RFC forward? There seems to be at least some \
support for the idea (attached)

Howard Chu wrote:
> Michael Matz via Binutils wrote:
> > Hello,
> > 
> > this is an RFC for now.  When met with some acceptance I'll cobble up a 
> > similar thing for gold as well and then make the libdep.so plugin only 
> > emit a warning message that its functionality is obsoleted and moved 
> > into ld itself.  As Cary put it back in 2020 when the plugin was added:
> > 
> > ( https://sourceware.org/pipermail/binutils/2020-December/114536.html )
> > 
> > "Did I miss any discussion about whether this feature should/could be
> > implemented directly in the linkers, rather than via a plugin? I
> > wouldn't be opposed to it."
> 
> I'm all for it. I went the plugin route initially because it seemed the
> easiest way to get the feature written and accepted but I agree with you,
> it'd be much more useful if it was implicitly supported by default.
> > 
> > I pretty much think that yes, the functionality absolutely needs to be in 
> > the linker itself, not in a plugin, at least if we want to see some use of 
> > it in the real world.  Amusingly I was triggered to look into this by 
> > libbfd itself:  Recently it got a dependency to libsframe and when 
> > shipping only static archives to build against (which we as distro 
> > consciously do) that leads to build errors in various 3rdparty packages 
> > wanting to link against libbfd (no matter how bad an idea that is).  Now, 
> > adding a '-plugin $magicdir/libdep.so' to the build flags of each such 
> > package is no better than just adding '-lsframe' in each case, so the 
> > plugin really doesn't help anything.  Had the functionality already been 
> > in the linker itself we could have just added 
> > "--record-libdeps='-lsframe'" when building libbfd.a and be done with it.
> > 
> > So, let's try to prepare for the future and at least now make ld interpret 
> > such dependencies on its own.
> > 
> > So, what do people think?
> > 
> > 
> > Ciao,
> > Michael.
> > 
> > ---------------------------------------
> > 
> > needing a plugin to interpret static archive dependencies (as added
> > by 'ar --record-libdeps') effectively means they are unused.
> > Which is too bad, because they are actually useful.  So implement
> > them in ld itself.
> 
> 
> 


-- 
  -- Howard Chu
  CTO, Symas Corp.           http://www.symas.com
  Director, Highland Sun     http://highlandsun.com/hyc/
  Chief Architect, OpenLDAP  http://www.openldap.org/project/


["[PATCH] ld: build libdep plugin only when shared library support is
 enabled.eml" (message/rfc822)]

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Subject: Re: [PATCH] ld: build libdep plugin only when shared library support
 is enabled
To: =?UTF-8?Q?Clément_Chigot?= <chigot@adacore.com>,
 binutils@sourceware.org
References: <20230413074914.354662-1-chigot@adacore.com>
From: Howard Chu <hyc@symas.com>
Message-ID: <5216d67e-ab2b-8142-edd8-4cab38ee2dc6@symas.com>
Date: Thu, 13 Apr 2023 09:54:02 +0100
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Clément Chigot via Binutils wrote:
> Otherwise, libtool will create a static plugin which cannot be loaded.
> Even worse on Windows, it will create a .a file, resulting in a similar
> bug than PR 27113: some tools will try to open it and Windows will raise
> a popup error.

At this point I think it'd be better to integrate the libdep functionality directly \
into ld, as suggested before:

https://sourceware.org/pipermail/binutils/2023-February/126155.html

-- 
  -- Howard Chu
  CTO, Symas Corp.           http://www.symas.com
  Director, Highland Sun     http://highlandsun.com/hyc/
  Chief Architect, OpenLDAP  http://www.openldap.org/project/



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