[Linux-kernel-mentees] [PATCH RFC] checkpatch: fix multi-statement macro checks
Joe Perches
joe at perches.com
Thu Oct 1 13:17:21 UTC 2020
On Thu, 2020-10-01 at 16:03 +0530, Dwaipayan Ray wrote:
> Checkpatch.pl doesn't have a check for excluding while (...) {...}
> blocks from MULTISTATEMENT_MACRO_USE_DO_WHILE error.
>
> For example, running checkpatch.pl on the file mm/access.c in the
> kernel generates the following error:
>
> ERROR: Macros with complex values should be enclosed in parentheses
> +#define copy_from_kernel_nofault_loop(dst, src, len, type, err_label) \
> + while (len >= sizeof(type)) { \
> + __get_kernel_nofault(dst, src, type, err_label); \
> + dst += sizeof(type); \
> + src += sizeof(type); \
> + len -= sizeof(type); \
> + }
>
> The error is misleading for this case. Enclosing it in parantheses
> doesn't make any sense.
OK
> Checkpatch already has an exception list for such common macro types.
> Added a new exception for while (...) {...} style blocks to the same.
> This effectively fixed the wrong error message.
[]
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
[]
> @@ -5342,6 +5342,7 @@ sub process {
> $dstat !~ /^\.$Ident\s*=/ && # .foo =
> $dstat !~ /^(?:\#\s*$Ident|\#\s*$Constant)\s*$/ && # stringification #foo
> $dstat !~ /^do\s*$Constant\s*while\s*$Constant;?$/ && # do {...} while (...); // do {...} while (...)
> + $dstat !~ /^while\s*$Constant\s*$Constant\s*$/ && # while (...) {...}
Did you try to output $dstat for some matching cases?
What was the $dstat value for the cases you tried?
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