#12741: R fails to build with LTO
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Reporter: SimonKing | Owner: tbd
Type: defect | Status: new
Priority: major | Milestone: sage-5.0
Component: packages | Resolution:
Keywords: R LTO | Work issues:
Report Upstream: N/A | Reviewers:
Authors: | Merged in:
Dependencies: | Stopgaps:
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Comment (by leif):
Replying to [comment:8 SimonKing]:
> Replying to [comment:7 SimonKing]:
> > I don't understand: At what point do I need to provide `-fuse-linker-
plugin`?
>
> Sorry, now I recall your comments from #12703, where you say that some
(not all) packages would need `-fuse-linker-plugin` added to `LDFLAGS` in
order to work with -lto.
Explicitly specifying `-fuse-linker-plugin` seems to only be necessary in
case you updated binutils (or your `ld`, or used some older version during
the GCC build) after building GCC.
From the GCC manual:
`-fuse-linker-plugin`
Enables the use of a linker plugin during link-time optimization. This
option relies on the linker plugin support in linker that is available in
gold or in GNU ld 2.21 or newer.
This option enables the extraction of object files with GIMPLE
bytecode out of library archives. This improves the quality of
optimization by exposing more code to the link-time optimizer. This
information specifies what symbols can be accessed externally (by non-LTO
object or during dynamic linking). Resulting code quality improvements on
binaries (and shared libraries that use hidden visibility) are similar to
`-fwhole-program`. See `-flto` for a description of the effect of this
flag and how to use it.
This option is enabled by default when LTO support in GCC is enabled
and GCC was configured for use with a linker supporting plugins (GNU ld
2.21 or newer or gold).
[[BR]]
It's IMHO a minor issue anyway.
[[BR]]
> However, how problematic is that my ld is slightly too old? Would it
refuse to work with `-fuse-linker-plugin`? Will it ignore that flag?
Nope, GCC will exit with an error ''if you specify `-fuse-linker-plugin`''
but the present linker doesn't support it.
[[BR]]
> I guess Sage shouldn't also add another 60MB or so for a binutils spkg,
isn't it?
We need a standard LaTeX / TeXLive package, too. ;-)
No, seriously, we could of course also offer an ''optional'' binutils
package, but that's not that important, although the GCC package may
refuse to build on systems with too incapable versions of the programs
provided by binutils.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/12741#comment:9>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
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