[haiku-bugs] Re: [Haiku] #6272: support for undefined weak symbols
- From: "bonefish" <trac@xxxxxxxxxxxx>
- Date: Tue, 06 Jul 2010 17:47:33 -0000
#6272: support for undefined weak symbols
----------------------------+-----------------------------------------------
Reporter: lucian | Owner: axeld
Type: bug | Status: closed
Priority: normal | Milestone: R1
Component: System/Kernel | Version: R1/Development
Resolution: fixed | Keywords:
Blocked By: | Has a Patch: 1
Platform: All | Blocking:
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Comment (by bonefish):
Replying to [comment:3 lucian]:
> I'm not sure how to read this binutils mailing list discussion:
http://sourceware.org/ml/binutils/2010-03/msg00173.html
>
> Because undefined weak references do not cause library archive symbols
to be pulled in to resolve them, IIRC.
>
> My interpretation is that the undefined weak symbol should only be
searched inside the image in which it appears, not in other images.
This is what the System V ABI specification has to say (chapter 4, Symbol
Table):
"When the link editor searches archive libraries [see ‘‘Archive File’’ in
Chapter 7], it extracts archive members that contain definitions of
undefined global symbols. The member’s definition may be either a global
or a weak symbol. The link editor does not extract archive members to
resolve undefined weak symbols. Unresolved weak symbols have a zero
value."
That pretty explicitly only refers to the link editor, i.e. the linker,
not the dynamic loader, and archive (i.e. static) libraries, which aren't
of relevance for the loader. I found no other mention of weak undefined
symbols in the specification. Sun seems to
[http://docs.sun.com/app/docs/doc/817-1984/6mhm7pl2g?a=view agree] with
this interpretation.
--
Ticket URL: <http://dev.haiku-os.org/ticket/6272#comment:4>
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