[lfs-dev] gcc test failures with current svn

Bruce Dubbs bruce.dubbs at gmail.com
Sun Aug 7 12:28:52 PDT 2016

Romain Geissler wrote:
> Hi,
> On Sun, 7 Aug 2016, Ken Moffat wrote:
>> On Sun, Aug 07, 2016 at 12:20:23PM -0500, Bruce Dubbs wrote:
>>> Ken Moffat wrote:
>>> Isn't -flto the gold linker?  I'm not sure.
>>> Didn't someone once say that if you don't follow the book and something
>>> breaks, that you get to keep the pieces?
>>> [snip]
>> Probably (-flto), certainly the book doesn't enable the plugins.
>> And yes, I'm keeping all the pieces.
> The book neither explicitly disable the linker plugin. So as we are
> using up to date binutils which supports the linker plugin, on a non
> exotic plateform like using ELF, then by default both binutils and gcc
> will be built with LTO and linker plugin support, whether you use gold
> or not.

Interesting.  I did not know that.

> About the build failures you are reporting, you only show the ones in
> the "guality" test folders. For me, whatever the gcc/binutils/gdb
> versions, these tests are always very flacky and I could never got them
> to work at 100% whatever the configuration I use.
> What are the "guality" tests ? Simply tests that checks that the
> generated debug symbols are fine. In other words, in these tests, gcc
> compiles some dummy programs with different options, then start them
> with gdb, and tries to put breakpoint and print values. In all the case
> I investigated on my side, the issue were that when printing values of
> variables in gdb, it often ended up printing "optimized out" rather than
> the real value. These tests are highly dependent on the gdb version you
> use. So in the end, gcc may be wrong, or maybe it is gcc that cannot
> properly read the gcc DWARF data, but the resulting code is fine, just
> the debugging may not be.

Romain, you do know that we run the gcc tests in a limited chroot 
environment where gdb is not available, right?  Shouldn't the tests that 
need gdb just be skipped?

   -- Bruce

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