On 4/30/23 12:30, Jeff Law wrote:
On 1/12/23 09:02, Longjun Luo via Gcc-patches wrote:
From 0821df518b264e754d698d399f98be1a62945e32 Mon Sep 17 00:00:00 2001
From: Longjun Luo <luolongj...@gmail.com>
Date: Thu, 12 Jan 2023 23:59:54 +0800
Subject: [PATCH] libcpp: suppress builtin macro redefined warnings for
__LINE__
As implied in
gcc.gnu.org/legacy-ml/gcc-patches/2008-09/msg00076.html,
gcc provides -Wno-builtin-macro-redefined to suppress warning when
redefining builtin macro. However, at that time, there was no
scenario for __LINE__ macro.
But, when we try to build a live-patch, we compare sections by using
-ffunction-sections. Some same functions are considered changed because
of __LINE__ macro.
At present, to detect such a changed caused by __LINE__ macro, we
have to analyse code and maintain a function list. For example,
in kpatch, check this commit
github.com/dynup/kpatch/commit/0e1b95edeafa36edb7bcf11da6d1c00f76d7e03d.
So, in this scenario, when we try to compared sections, it would
be better to support suppress builtin macro redefined warnings for
__LINE__ macro.
Signed-off-by: Longjun Luo <luolongj...@gmail.com>
---
gcc/testsuite/gcc.dg/builtin-redefine-1.c | 49 +++++++++++++++++++++++
gcc/testsuite/gcc.dg/builtin-redefine.c | 24 +++++++++--
libcpp/init.cc | 2 +-
3 files changed, 70 insertions(+), 5 deletions(-)
create mode 100755 gcc/testsuite/gcc.dg/builtin-redefine-1.c
Thanks. I added a suitable ChangeLog and pushed this to the trunk.
This is causing regressions on various targets for a few tests:
lm32-sim: c-c++-common/cpp/pr92296-2.c -Wc++-compat (test for
warnings, line 41)
lm32-sim: gcc.dg/cpp/undef2.c (test for warnings, line 9)
lm32-sim: gcc.dg/cpp/undef2.c (test for excess errors)
I have reverted this patch from the trunk. Please address the
regressions and resubmit.
Thanks,
Jeff
