elf: Avoid nested functions in the loader (aarch64, x86-64) [BZ #27220]maskray/nesting

dynamic-link.h is included more than once in some elf/ files (rtld.c,
dl-conflict.c, dl-reloc.c, dl-reloc-static-pie.c) and uses GCC nested
functions. This harms readability and the nested functions usage
is the biggest obstacle prevents CC=clang (which doesn't support the
feature).

To un-nest elf_machine_rela, the key idea is to pass the variable in
the containing scope as an extra argument.
Stan Shebs implemented this in the google/grte/v5-2.27/master branch.
This patch squashes and cleans up the commits.

This patch just fixes aarch64 and x86-64: they use the `#ifndef NESTING`
branch to avoid nested functions. The `#ifdef NESTING` branch is used by
all other ports whose dl-machine.h files haven't been migrated.

For the time being, there is some duplicated code. `#ifdef NESTING`
dispatches can be removed in the future when all arches are migrated.

I can fix powerpc64, riscv, and other arches subsequently.
Migrating all ports at once is just too risky. Also, appreciate help
from arch maintainers.

Tested on {aarch64,x86_64}-linux-gnu (!NESTING) and
powerpc64le-linux-gnu (NESTING).

0 files changed, 0 insertions, 0 deletions