Re: [PATCH] fix ___SYNC () build error when PROFILE_ALL_BRANCHES is enabled

[genjian zhang]

On Wed, Apr 26, 2023 at 8:51 PM Genjian <zhanggenjian123@xxxxxxxxx> wrote:
>
> From: Genjian Zhang <zhanggenjian@xxxxxxxxxx>
>
> compiler error (mips-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110):
>
> {standard input}: Assembler messages:
> {standard input}:171: Error: found '(', expected: ')'
> {standard input}:171: Error: found '(', expected: ')'
> {standard input}:171: Error: non-constant expression in ".if" statement
> {standard input}:171: Error: junk at end of line, first unrecognized
> character is `('
>
> Preprocessor expand ___SYNC () macros.However,'if' will be wrongly
> replaced by C code when PROFILE_ALL_BRANCHES is enabled and ___SYNC
> is used in inline assembly.This leads to syntax errors in the code.
> Compilers report a lot of errors like the above.
> Move '.if' into quoted strings to fix it.
>
> Reported-by: k2ci <kernel-bot@xxxxxxxxxx>
> Signed-off-by: Genjian Zhang <zhanggenjian@xxxxxxxxxx>
> ---
>  arch/mips/include/asm/sync.h | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/arch/mips/include/asm/sync.h b/arch/mips/include/asm/sync.h
> index aabd097933fe..d9f5a87424e7 100644
> --- a/arch/mips/include/asm/sync.h
> +++ b/arch/mips/include/asm/sync.h
> @@ -175,7 +175,7 @@
>   */
>  #ifdef CONFIG_CPU_HAS_SYNC
>  # define ____SYNC(_type, _reason, _else)                       \
> -       .if     (( _type ) != -1) && ( _reason );               \
> +       ((_type) != -1) && (_reason);                           \
>         .set    push;                                           \
>         .set    MIPS_ISA_LEVEL_RAW;                             \
>         .rept   __SYNC_rpt(_type);                              \
> @@ -192,13 +192,15 @@
>  /*
>   * Preprocessor magic to expand macros used as arguments before we insert them
>   * into assembly code.
> + * In addition,‘if’ can not be substituted when CONFIG_PROFILE_ALL_BRANCHES is
> + * enabled.
>   */
>  #ifdef __ASSEMBLY__
>  # define ___SYNC(type, reason, else)                           \
> -       ____SYNC(type, reason, else)
> +       .if     ____SYNC(type, reason, else)
>  #else
>  # define ___SYNC(type, reason, else)                           \
> -       __stringify(____SYNC(type, reason, else))
> +       ".if"   __stringify(____SYNC(type, reason, else))
>  #endif
>
>  #define __SYNC(type, reason)                                   \
> --
> 2.25.1
>

Maybe the readability of this modification is not very good. Any
comments and suggestions are welcome. Thanks.