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Re: Possible code defects: macros and precedence

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On Sat, 3 Sep 2016, Joe Perches wrote:

> There are many nominally incorrect macro definitions
> in linux-kernel source where parentheses are not used
> for various macros arguments with calculations.
>
> Does coccinelle or smatch have the ability to detect
> potential macro misuse where arguments passed to the
> macro are not correctly parenthesized by the macro?
>
> Something like:
>
> 	#define A 1
> 	#define B 2
> 	#define shift(val) (val << 1)
>
> where a use is:
>
> 	int c = shift(A | B)
>
> where the actual result is 5 but the expected result is 6?
>
> Can either tool suggest changing the macro to
>
> 	#define shift(val) ((val) << 1)

Coccinelle could do this.  It is possible to match macro parameters, and
it is possible to match binary operators generically.  I can look into it.

julia

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Thread

Possible code defects: macros and precedence Joe Perches <joe@perches.com> - 2016-09-03 20:40 +0200
  Re: Possible code defects: macros and precedence Dan Carpenter <dan.carpenter@oracle.com> - 2016-09-03 22:20 +0200
    [PATCH] checkpatch: Add a --strict test for macro argument reuse and precedence Joe Perches <joe@perches.com> - 2016-09-04 00:30 +0200
      Re: [PATCH] checkpatch: Add a --strict test for macro argument  reuse and precedence Joe Perches <joe@perches.com> - 2016-09-04 16:50 +0200
  Re: Possible code defects: macros and precedence Julia Lawall <julia.lawall@lip6.fr> - 2016-09-04 12:20 +0200
    Re: Possible code defects: macros and precedence Joe Perches <joe@perches.com> - 2016-09-04 17:10 +0200

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