https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47857
--- Comment #10 from CVS Commits ---
The master branch has been updated by Lewis Hyatt :
https://gcc.gnu.org/g:9938645fcf914ec2a3fa8137cf1456ad4af5f77c
commit r14-5471-g9938645fcf914ec2a3fa8137cf1456ad4af5f77c
Author: Lewis Hyatt
Date: Fri Nov 10 11:10:18 2023 -0500
c-family: Let libcpp know when the compilation is for a PCH [PR9471]
libcpp will generate diagnostics when it encounters things in the main file
that only belong in a header file, such as `#pragma once' or `#pragma GCC
system_header'. But sometimes the main file is a header file that is just
being compiled separately, e.g. to produce a C++ module or a PCH, in which
case such diagnostics should be suppressed. libcpp already has an interface
to request that, so make use of it in the C frontends to prevent libcpp
from
issuing unwanted diagnostics when compiling a PCH.
gcc/c-family/ChangeLog:
PR pch/9471
PR pch/47857
* c-opts.cc (c_common_post_options): Set cpp_opts->main_search
so libcpp knows it is compiling a header file separately.
gcc/testsuite/ChangeLog:
PR pch/9471
PR pch/47857
* g++.dg/pch/main-file-warnings.C: New test.
* g++.dg/pch/main-file-warnings.Hs: New test.
* gcc.dg/pch/main-file-warnings.c: New test.
* gcc.dg/pch/main-file-warnings.hs: New test.
