[gentoo-user] upgrading to gcc-f (was: chromium 60 build failure)

[allan gottlieb]

On Mon, Jul 31 2017, Mateusz Lenik wrote:

> On Mon, Jul 31, 2017 at 08:02:34PM +0000, Grant Edwards wrote:
>> ../../third_party/vulkan-validation-layers/src/loader/debug_report.c:50:5:
>> note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to
>> compile your code
>> ../../third_party/vulkan-validation-layers/src/loader/debug_report.c:
>> In function ‘util_CreateDebugReportCallbacks’:
>> ../../third_party/vulkan-validation-layers/src/loader/debug_report.c:235:5:
>> error: ‘for’ loop initial declarations are only allowed in C99 or
>> C11 mode
>
> Most likely gcc-4.9 defaults to older C standard (C89, I guess).
> The easiest way to solve this would be to update your gcc to 5.4,
> otherwise you'd have to pass one of the suggested flags to the compiler
> somehow.

gcc-config -l reports
 [1] x86_64-pc-linux-gnu-4.9.3
 [2] x86_64-pc-linux-gnu-4.9.4 *
 [3] x86_64-pc-linux-gnu-5.4.0

The news item from 2015-10-22 suggests (I have gentoolkit-0.3.3)
  # revdep-rebuild --library 'libstdc++.so.6' -- --exclude gcc

Is that the entire procedure needed?  In particular, ignoring
performance, can I avoid emerge --emptytree and just execute?

  # gcc-config x86_64-pc-linux-gnu-5.4.0
  # revdep-rebuild --library 'libstdc++.so.6' -- --exclude gcc

thanks,
allan