Re: [PULL 00/12] Compile QEMU with -Wimplicit-fallthrough

[Thomas Huth]

On 17/12/2020 00.01, no-reply@patchew.org wrote:
> Patchew URL: 20201216172949.57380-1-thuth@redhat.com/">https://patchew.org/QEMU/20201216172949.57380-1-thuth@redhat.com/
> 
> 
> 
> Hi,
> 
> This series seems to have some coding style problems. See output below for
> more information:
> 
> Type: series
> Message-id: 20201216172949.57380-1-thuth@redhat.com
> Subject: [PULL 00/12] Compile QEMU with -Wimplicit-fallthrough
> 
> === TEST SCRIPT BEGIN ===
> #!/bin/bash
> git rev-parse base > /dev/null || exit 0
> git config --local diff.renamelimit 0
> git config --local diff.renames True
> git config --local diff.algorithm histogram
> ./scripts/checkpatch.pl --mailback base..
> === TEST SCRIPT END ===
> 
> Updating 3c8cf5a9c21ff8782164d1def7f44bd888713384
> From https://github.com/patchew-project/qemu
>  * [new tag]         patchew/20201216172949.57380-1-thuth@redhat.com -> 
> patchew/20201216172949.57380-1-thuth@redhat.com
> Switched to a new branch 'test'
> 7bedbc8 configure: Compile with -Wimplicit-fallthrough=2
> e14bb9d tests/fp: Do not emit implicit-fallthrough warnings in the softfloat 
> tests
> ebd3c45 tcg/optimize: Add fallthrough annotations
> cfe5662 target/sparc/win_helper: silence the compiler warnings
> 8ef9335 target/sparc/translate: silence the compiler warnings
> 4588bf9 accel/tcg/user-exec: silence the compiler warnings
> be2108e hw/intc/arm_gicv3_kvm: silence the compiler warnings
> 7d033d0 target/i386: silence the compiler warnings in gen_shiftd_rm_T1
> 284b00a hw/timer/renesas_tmr: silence the compiler warnings
> c3d2957 hw/rtc/twl92230: Silence warnings about missing fallthrough statements
> 1b1609c target/unicore32/translate: Add missing fallthrough annotations
> 99bc0f0 disas/libvixl: Fix fall-through annotation for GCC >= 7
> 
> === OUTPUT BEGIN ===
> 1/12 Checking commit 99bc0f0e92b7 (disas/libvixl: Fix fall-through annotation 
> for GCC >= 7)
> ERROR: do not use C99 // comments
> #49: FILE: disas/libvixl/vixl/globals.h:111:
> +// Fallthrough annotation for Clang and C++11(201103L).
> 
> ERROR: do not use C99 // comments
> #52: FILE: disas/libvixl/vixl/globals.h:114:
> +// Fallthrough annotation for GCC >= 7.

Well, libvixl is C++ code and the upstream patch used these comments, too,
so this error can be ignored.

> total: 2 errors, 0 warnings, 24 lines checked
> 
> Patch 1/12 has style problems, please review.  If any of these errors
> are false positives report them to the maintainer, see
> CHECKPATCH in MAINTAINERS.
> 
> 2/12 Checking commit 1b1609c7573a (target/unicore32/translate: Add missing 
> fallthrough annotations)
> 3/12 Checking commit c3d2957383b8 (hw/rtc/twl92230: Silence warnings about 
> missing fallthrough statements)
> 4/12 Checking commit 284b00aef566 (hw/timer/renesas_tmr: silence the compiler 
> warnings)
> 5/12 Checking commit 7d033d02b90d (target/i386: silence the compiler warnings 
> in gen_shiftd_rm_T1)
> 6/12 Checking commit be2108e641c9 (hw/intc/arm_gicv3_kvm: silence the 
> compiler warnings)
> 7/12 Checking commit 4588bf97482b (accel/tcg/user-exec: silence the compiler 
> warnings)
> 8/12 Checking commit 8ef9335f2838 (target/sparc/translate: silence the 
> compiler warnings)
> 9/12 Checking commit cfe56623ece8 (target/sparc/win_helper: silence the 
> compiler warnings)
> 10/12 Checking commit ebd3c45fd052 (tcg/optimize: Add fallthrough annotations)
> WARNING: architecture specific defines should be avoided
> #35: FILE: include/qemu/compiler.h:230:
> +#if __has_attribute(fallthrough)

Maybe we should teach checkpatch.pl to allow these in compiler.h?

 Thomas