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    SubjectRe: [PATCH 4/5] drivers: staging: erofs: Fix parentheses error in macro
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    Hi Aaron,

    On 2018/12/11 18:54, Aaron Strahlberger wrote:
    > Fix of ERROR: Macros with complex values should be enclosed in parentheses
    > from checkpatch.pl
    >
    > Signed-off-by: Aaron Strahlberger <aaron.strahlberger@posteo.de>
    > Signed-off-by: Julius Wiedmann <julius.wiedmann@fau.de>
    > Signed-off-by: Dominik Huber <domi250@gmx.de>
    > ---
    > drivers/staging/erofs/erofs_fs.h | 4 ++--
    > 1 file changed, 2 insertions(+), 2 deletions(-)
    >
    > diff --git a/drivers/staging/erofs/erofs_fs.h b/drivers/staging/erofs/erofs_fs.h
    > index d4bffa2852b3..892c913960c3 100644
    > --- a/drivers/staging/erofs/erofs_fs.h
    > +++ b/drivers/staging/erofs/erofs_fs.h
    > @@ -38,9 +38,9 @@ struct erofs_super_block {
    > /* 80 */__u8 reserved2[48]; /* 128 bytes */
    > } __packed;
    >
    > -#define __EROFS_BIT(_prefix, _cur, _pre) enum { \
    > +#define __EROFS_BIT(_prefix, _cur, _pre) (enum { \
    > _prefix ## _cur ## _BIT = _prefix ## _pre ## _BIT + \
    > - _prefix ## _pre ## _BITS }
    > + _prefix ## _pre ## _BITS })

    It seems not the valid C, here is the compiler error:

    ...

    In file included from drivers/staging/erofs/internal.h:25:0,
    from drivers/staging/erofs/xattr.h:16,
    from drivers/staging/erofs/xattr.c:14:
    drivers/staging/erofs/erofs_fs.h:41:43: error: expected identifier or ‘(’ before ‘enum’
    #define __EROFS_BIT(_prefix, _cur, _pre) (enum { \
    ^
    drivers/staging/erofs/erofs_fs.h:65:1: note: in expansion of macro ‘__EROFS_BIT’
    __EROFS_BIT(EROFS_I_, DATA_MAPPING, VERSION);
    ^~~~~~~~~~~
    make[3]: *** [scripts/Makefile.build:292: drivers/staging/erofs/xattr.o] Error 1

    ...


    the __EROFS_BIT marco is used to define yyy_BIT according to xxx_BIT + xxx_BITS for cascade, eg.

    __EROFS_BIT(EROFS_I_, DATA_MAPPING, VERSION);
    it will defines EROFS_I_DATA_MAPPING_BIT = EROFS_I_VERSION_BIT + EROFS_I_VERSION_BITS;

    __EROFS_BIT(EROFS_I_, FEATURE2, DATA_MAPPING);
    it will defines EROFS_I_FEATURE2_BIT = EROFS_I_DATA_MAPPING_BIT + EROFS_I_DATA_MAPPING_BITS;


    Thanks,
    Gao Xiang

    >
    > /*
    > * erofs inode data mapping:
    >

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