Re: [PATCH] coccinelle: add style check for assignment in if

[Julia Lawall <julia.lawall@lip6.fr>]

On Sat, 15 Aug 2015, Kris Borer wrote:

> Add a semantic patch for fixing some cases of checkpatch.pl error:
> 
> ERROR: do not use assignment in if condition
> 
> Reviewed-by: Julia Lawall <julia.lawall@lip6.fr>

Sorry, but I'm not done reviewing it.  I have a lot of changes to propose.  
Is this different than the RFC v2?

julia

> Signed-off-by: Kris Borer <kborer@gmail.com>
> ---
>  scripts/coccinelle/style/assignment_in_if.cocci | 92 +++++++++++++++++++++++++
>  1 file changed, 92 insertions(+)
>  create mode 100644 scripts/coccinelle/style/assignment_in_if.cocci
> 
> diff --git a/scripts/coccinelle/style/assignment_in_if.cocci b/scripts/coccinelle/style/assignment_in_if.cocci
> new file mode 100644
> index 0000000..22ab161
> --- /dev/null
> +++ b/scripts/coccinelle/style/assignment_in_if.cocci
> @@ -0,0 +1,92 @@
> +// find checkpatch.pl errors of the type:
> +//	ERROR: do not use assignment in if condition
> +//
> +// This script is designed to correct code where assignments exist in if
> +// conditions. It is only capable of handling a subset of such problems.
> +//
> +// For example:
> +//
> +//	if(result = myfun())
> +//
> +// would become:
> +//
> +//	result = myfun();
> +//	if(result)
> +//
> +// Confidence: Moderate
> +
> +
> +// if ( ret = call() )
> +@if1@
> +identifier i;
> +expression E;
> +statement S1, S2;
> +@@
> +
> ++ i = E;
> +  if (
> +- (i = E)
> ++ i
> +  ) S1 else S2
> +
> +
> +// if ( (ret = call()) < 0 )
> +@if2@
> +identifier i;
> +expression E;
> +statement S1, S2;
> +binary operator b;
> +@@
> +
> ++ i = E;
> +  if (
> +- (i = E)
> ++ i
> +  b ... ) S1 else S2
> +
> +// if ( ptr->fun && (ret = ptr->fun()) < 0 )
> +@if3@
> +identifier i, i2;
> +expression E1, E2;
> +constant c;
> +binary operator b;
> +@@
> +
> ++ if( E1->i ) {
> ++  	i2 = E2;
> ++ 	if (i2 b c) {
> +- if( E1->i && ((i2 = E2) b c) ) {
> +  ...
> +- }
> ++ 	}
> ++ }
> +
> +// if ( (ret = call()) < 0 && ret != -1 )
> +@if4@
> +identifier i;
> +expression E, E2;
> +statement S1, S2;
> +binary operator b;
> +@@
> +
> ++ i = E;
> +  if (
> +- (i = E)
> ++ i
> +  b
> +  ... && E2 ) S1 else S2
> +
> +// if ( (ret = call()) < 0 && ret != -1 && ret != -2 )
> +@if5@
> +identifier i;
> +expression E, E2, E3;
> +statement S1, S2;
> +binary operator b;
> +@@
> +
> ++ i = E;
> +  if (
> +- (i = E)
> ++ i
> +  b
> +  ... && E2 && E3 ) S1 else S2
> -- 
> 1.9.1
> 
>