This is the mail archive of the
mailing list for the binutils project.
Re: [PATCH] ld: Add '--defined' command line option.
- From: Andrew Burgess <andrew dot burgess at embecosm dot com>
- To: Nick Clifton <nickc at redhat dot com>
- Cc: binutils at sourceware dot org
- Date: Thu, 23 Jul 2015 22:34:21 +0100
- Subject: Re: [PATCH] ld: Add '--defined' command line option.
- Authentication-results: sourceware.org; auth=none
- References: <1437426340-25537-1-git-send-email-andrew dot burgess at embecosm dot com> <55B0CF5A dot 1030901 at redhat dot com>
Thanks for the review.
* Nick Clifton <firstname.lastname@example.org> [2015-07-23 12:26:18 +0100]:
> I like this patch in principle, but there are a few problems with it at
> the moment:
> * Is this patch really necessary ? Can the same affect not be achieved by
> combining --undefined= and --no-undefined ? If not, why not ?
The option --no-undefined controls how the linker handles references
to undefined symbols (within relocs) rather than the general presence
of undefined symbols. So, unless I'm missing something, I don't think
there's any overlap here.
For example, trying 'ld -u blah --no-undefined -o test.exe test.obj'
doesn't cause any errors.
> * I think that the name of the option, --defined is slightly confusing.
> When I first read your submission I thought that it meant that a defined
> symbol was being created, ie that it was an alias of --defsym. So how about
> a different name ? For example --no-allow-undef=<foo>. [This version might
> even be extended so the the inverse option --allow-undef=<foo> would stop
> --no-undefined from complaining if that particular symbol was undefined].
> Or how about --undefined-and-err= so that the connection with --undefined is
> more obvious ?
I'm not massively attached to the flag name. The no-allow-undef /
allow-undef though a nice idea would still require --undefined to be
used, I'd like to have a single flag, to reduce the chance of user
That leaves --undefined-and-err from your suggestions, or how about
--require-defined=SYM, it doesn't have the same connection with
--undefined, but I think that might be nicer.
That being said, I'm not too bothered by the flag name.
> * The documentation needs to be extended. You need an entry in the
> ld/NEWS file and an update to the --undefined entry in ld/ld.texinfo
> referring the reader to the new option and explaining why they might want to
> use it instead.
> * The new tests need to be extend to make sure that the linker does not
> complain if the defined symbol does exist, and that the new option does
> duplicate the behaviour of the --undefined option.
I'll address these when we've reached consensus about the above.