Re: 4.6.1-RC1: Using LTO in canadian cross

[Ian Lance Taylor <iant at google dot com>]

Georg-Johann Lay <avr@gjlay.de> writes:

> Tryint to use LTO with a canadian cross gcc I get the following error
> message:
>
> e:/winavr/4.6.1/bin/../lib/gcc/avr/4.6.1/../../../../avr/bin/ld.exe:
> unrecognized option '-plugin'
>
> It's binutils 2.21 configured
>
> Configured with: ../../source/binutils-2.21/configure --target=avr
> --prefix=/local/gnu/install/gcc-4.6-mingw32 --host=i586-mingw32
> --build=i686-linux-gnu

You need to configure with --enable-plugins.  But I'll add that I don't
know whether plugins work on a Windows host.  They may work; I just
don't know.


> In the ChangeLogs I found that support for libelf has been removed, so
> I guess it's simply not needed any more?

Correct.


> Yet another question: The above run generated temorary file names like
> c:\Temp\cc0oaaaa.res which is a bit annoying when comparing testsuite
> .log files.  Is thare a way so that different rund generate same file
> name(s)?

The simplest way is to use the --save-temps option.


> Then I read somewhere that LTO does not work together with -g. Is that
> still true for 4.6/4.7 or did I ran in some documentation-rot?

I believe that some aspects of -g still do not work correctly with LTO,
but basic debugging does work.  I think that some type information is
not correctly conveyed to the debugger, but you can still print
variables, structs, etc.

Ian