Re: [PATCH] CFLAGS: add -Wunused-but-set-parameter

[Andrew Morton]

On Fri, 8 Jul 2016 00:43:06 +0300 Alexey Dobriyan <adobriyan@xxxxxxxxx> wrote:

> -Wunused-but-set-parameter is finding stuff with current allmodconfig:
> 
> drivers/misc/mic/scif/scif_dma.c:118:27: warning: parameter 'ep' set but not used [-Wunused-but-set-parameter]
> drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_hw.c:2156:8: warning: parameter 'function' set but not used [-Wunused-but-set-parameter]
> drivers/net/ethernet/ti/tlan.c:1647:59: warning: parameter 'host_int' set but not used [-Wunused-but-set-parameter]
> drivers/usb/gadget/udc/pxa27x_udc.c:1828:74: warning: parameter 'driver' set but not used [-Wunused-but-set-parameter]
> 
> and judging by changelogs, people were using it before,
> but were too scared to touch top level Makefile.
>
> ...
>
> --- a/Makefile
> +++ b/Makefile
> @@ -399,6 +399,7 @@ KBUILD_CFLAGS   := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
>  		   -Werror-implicit-function-declaration \
>  		   -Wno-format-security \
>  		   -std=gnu89
> +KBUILD_CFLAGS += -Wunused-but-set-parameter
>  
>  KBUILD_AFLAGS_KERNEL :=
>  KBUILD_CFLAGS_KERNEL :=

gcc-4.4.4:

  CHK     include/config/kernel.release
  CHK     include/generated/uapi/linux/version.h
  CHK     include/generated/utsrelease.h
  CC      scripts/mod/empty.o
  CC      scripts/mod/devicetable-offsets.s
cc1: error: unrecognized command line option "-Wunused-but-set-parameter"
make[2]: *** [scripts/mod/empty.o] Error 1
make[2]: *** Waiting for unfinished jobs....
cc1: error: unrecognized command line option "-Wunused-but-set-parameter"
make[2]: *** [scripts/mod/devicetable-offsets.s] Error 1