Re: Questions when put in the compiler -wExtra option

[Yunseong Kim <yskelg@xxxxxxxxx>]

Hi, I am Yunseong Kim.

I was looking for an appropriate topic for -wExtra compilation options
and came across this threads.

The below make build a lot of warnings(attachement file are build log
with warnings) compared to the Linux kernel,
is it something that would benefit the Xen hypervisor to apply removing
warning for the code?

The additional no options were added to ensure that Xen compiles
successfully when the wError compiler flag is added.

They are all printed as warnings.

$ make allyesconfig

$ CFLAGS="-g -O0 -Wextra -Wno-error=unused-parameter
-Wno-error=sign-compare -Wno-error=empty-body
-Wno-error=old-style-declaration -Wno-error=type-limits" time make -j4
2>&1 | tee xen-build.log


I have a question about the prioritization of fixes for the warning items.

If some of the warnings the Xen hypervisor detects aren't critical for
its operation, I wouldn't want to submit a patch that might introduce
unnecessary complexity.

Would it be helpful to clarify which fixes are considered some of priority?


My compile environment is Arm64 Ubuntu 22.04

$ uname -a
Linux paran-QEMU-Virtual-Machine 6.5.0-35-generic #35~22.04.1-Ubuntu SMP
PREEMPT_DYNAMIC Tue May  7 11:19:33 UTC 2 aarch64 aarch64 aarch64 GNU/Linux

$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/aarch64-linux-gnu/12/lto-wrapper
Target: aarch64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu
12.3.0-1ubuntu1~22.04'
--with-bugurl=file:///usr/share/doc/gcc-12/README.Bugs
--enable-languages=c,ada,c++,go,d,fortran,objc,obj-c++,m2 --prefix=/usr
--with-gcc-major-version-only --program-suffix=-12
--program-prefix=aarch64-linux-gnu- --enable-shared
--enable-linker-build-id --libexecdir=/usr/lib
--without-included-gettext --enable-threads=posix --libdir=/usr/lib
--enable-nls --enable-clocale=gnu --enable-libstdcxx-debug
--enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new
--enable-gnu-unique-object --disable-libquadmath
--disable-libquadmath-support --enable-plugin --enable-default-pie
--with-system-zlib --enable-libphobos-checking=release
--with-target-system-zlib=auto --enable-objc-gc=auto --enable-multiarch
--enable-fix-cortex-a53-843419 --disable-werror
--enable-checking=release --build=aarch64-linux-gnu
--host=aarch64-linux-gnu --target=aarch64-linux-gnu
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 12.3.0 (Ubuntu 12.3.0-1ubuntu1~22.04)


Warm Regards,

Yunseong Kim

Attachment: xen-build.log
Description: Text document