Gentoo Archives: gentoo-mips

From: Mike Frysinger <vapier@g.o>
To: gentoo-mips@l.g.o
Cc: "Michał Górny" <mgorny@g.o>, basile@××××××××××××××.edu
Subject: Re: [gentoo-mips] Re: On MIPS using the same CHOST for all multilib ABIs
Date: Sun, 29 Dec 2013 23:56:16
In Reply to: Re: [gentoo-mips] Re: On MIPS using the same CHOST for all multilib ABIs by "Michał Górny"
1 On Sunday 29 December 2013 17:04:34 Michał Górny wrote:
2 > Dnia 2013-12-29, o godz. 16:52:05 "Anthony G. Basile" napisał(a):
3 > > On 12/29/2013 04:48 PM, Markos Chandras wrote:
4 > > > Yes all 3 ABIs use the same tuple.
5 > >
6 > > I think people are missing Mike's point from earlier, which is that
7 > > tuples label toolchains and a toolchain can support multiple abis. So
8 > > for example, what would one do on a system which simultaneously has o32,
9 > > n32 and n64? -gnuabi32n32n64 looks pretty crazy.
10 >
11 > I'd say that we shouldn't limit the concept of 'toolchain' to
12 > specifically GNU binutils + GNU gcc. Configure scripts can require much
13 > more tools (like assemblers, *-config tools including pkg-config)
14 > and I doubt we should really assume they all have some magic support
15 > for ABI switching we had taken care of.
17 the problem you pointed out is a limitation in our code: we cannot assume
18 CHOST is unique for an ABI, thus using that as a unique path in generating ABI
19 headers is wrong. conflating that bug in our code with any other issue is
20 wrong. you can easily use ${CHOST}/${ABI} or ${CHOST}-${ABI} or just ${ABI}
21 (since /usr/include is already associated with ${CHOST}).
23 when it comes to *-config tools, those are known to be old and crap (for many
24 more reasons than just multilib/cross-compiling). convert to .pc files and use
25 pkg-config instead.
27 > That said, it would be actually more reasonable to have three separate
28 > triples for those ABIs, and link them to the same application if it
29 > supports all three ABIs. Of course, we would need to ensure that
30 > the application actually respects the triple via which it was called.
32 creating a unique tuple is feasible via the vendor field as a last resort.
33 however, unless you have a compelling reason to do so, i don't think it makes
34 sense to pursue it. other than the vendor field, we are limited by what
35 upstream GNU does and in that regard, they haven't always used unique tuples
36 for ABI selection (this isn't limited to MIPS either).
38 so to turn your base argument around, we shouldn't be limiting Gentoo to only
39 support CHOSTs that also select ABIs uniquely.
40 -mike


File name MIME type
signature.asc application/pgp-signature