[PATCH 0/1] gas: add new command line option --no-group-check

[Tan Yuan <tanyuan@tinylab.org>]

Hi, list

This patch introduces a new option that allows suppressing the warning
when attaching a group to a section that already belongs to a group.

The kernel extensively uses the ".pushsection" directive, which poses
issues with proper reference building and garbage collection. To address
this problem, the kernel uses "KEEP" in the linker script to prevent
certain sections from being garbage collected. Consequently, some
sections that should have been garbage collected are retained. For
instance, if the section pusher is being garbage collected, the pushed
sections are also supposed to be collected, but the linker script
retains them.

To resolve this, we can utilize ".attach_to_group" alongside
".pushsection," which enables the section pusher and the pushed sections
to be grouped together, making them either eligible for garbage
collection or kept together.

Currently, the kernel encapsulates the use of ".pushsection" within
macros, leading to thousands of instances where these macros are
expanded. Rather than adding ".attach_to_group" to a thousand functions,
we can incorporate it into this macro. However, some functions expand
this macro multiple times, resulting in multiple attachments to the
group for those functions. Unfortunately, there is no alternative method
to ensure a single expansion of ".attach_to_group" As a solution, we
propose adding an option to address this issue.

Thanks.

Tan Yuan (1):
  gas: add new command line option --no-group-check

 gas/as.c             | 10 +++++++++-
 gas/as.h             |  3 +++
 gas/config/obj-elf.c |  2 +-
 gas/doc/as.texi      |  4 ++++
 4 files changed, 17 insertions(+), 2 deletions(-)

-- 
2.41.0