Re: [PATCH v3 0/5] sim: Suppress warnings if built with Clang

[Andrew Burgess <aburgess@redhat.com>]

Tsukasa OI <research_trasio@irq.a4lg.com> writes:

> Hello,
>
> This is the version 2 patchset to suppress Clang compiler warnings
> (causes a build failure due to default -Werror).
>
>
> [Background]
>
> When we build Binutils and GDB with Clang, it causes a build failure due to
> warnings generated by Clang and the default -Werror configuration.
>
> I MOSTLY managed to make ALL ARCHITECTURE ENABLED Binutils and GDB
> -Werror-free on Clang 15.0.0 (note that this does not necessarily mean
> warning-free) and this patchset is a part of it (common simulator parts).
>
> -   It still requires -Wno-implicit-function-declaration on the
>     LatticeMicro32 and M32R simulators.  Except them, most of Binutils / GDB
>     components can be built with Clang by default with my tree.
> -   I noticed that the assembler is not tested enough (because just with
>     --enable-targets=all, it builds only host assembler).
>
> Full Clang 15.0.0 -Werror-free branch in development is available at:
> <https://github.com/a4lg/binutils-gdb/tree/clang-nowarn-dev>
>
> Tested configuration:
> -   Ubuntu 22.04.1 LTS (x86_64)
> -   LLVM / Clang 15.0.0 (built from source)
> -   Configuration examples:
>     $srcdir/configure \
>         --enable-targets=all \
>         --enable-multilib --enable-ld --enable-gold --enable-nls \
>         CC=clang CXX=clang++ CCLD=clang CXXLD=clang++ \
>         CFLAGS='  -O2 -g -Wno-implicit-function-declaration' \
>         CXXFLAGS='-O2 -g -Wno-implicit-function-declaration'
>     $srcdir/configure \
>         --target=riscv64-unknown-linux-gnu \
>         --enable-multilib --enable-ld --enable-gold --enable-nls \
>         CC=clang CXX=clang++ CCLD=clang CXXLD=clang++ \
>         CFLAGS='-O2 -g' CXXFLAGS='-O2 -g'
>
>
> [About this Patchset]
>
> This patchset contains four five fixes to the files under sim{,/common}.
> Each contains minor fixes to suppress Clang / GCC warnings.
>
> Each change is detailed in the each patch.
>
>
> [Changes: v2 -> v3]
>
> -   PATCH 2/5: Rewritten predicate macros from (!!x) to (x != 0).
>     (This is based on the feedback by Andrew Burgess).
> -   PATCH 3/5: Replaced with a patch by Andrew Burgess
>     (slightly modified by me).
> -   PATCH 4/5: Fix cached variable from ld_cv_* to sim_cv_*.
> -   Removed ChangeLog from commit messages
>     (based on the feedback [to another patchset by me] by Bruno Larsen).
>
>
> [Changes: v1 -> v2]
>
> -   Commit messages are improved
> -   PATCH v1 1/4 is Moved to another patchset
> -   PATCH v1 2-4/4 -> PATCH v2 1-3/5
> -   New: Check known getopt definition on sim (PATCH v2 4/5)
>     This test is already performed on binutils, gas, gprof and ld and this
>     commit does the same to sim.
> -   New: Initialize pbb_br_* by default (PATCH v2 5/5)
>     It did not generate warnings on Clang but GCC creates some warnings
>     (although those are not reported as errors).
>     This is due to uninitialized pbb_br_* variables and this commit fixes
>     the issue by initializing them by a harmless value.

Thanks for the updated patches.  I reviewed these and pushed them with a
couple of minor updates, I'll follow up to each patch with the changes I
made.

Thanks,
Andrew