[bvanassche:tracing 2/2] include/linux/compiler.h:246:47: warning: ordered comparison of pointer with null pointer

From: kernel test robot
Date: Wed Aug 24 2022 - 16:50:58 EST


tree: https://github.com/bvanassche/linux tracing
head: e50691460d5ea5a49b903e0ea50276e942b6f34f
commit: e50691460d5ea5a49b903e0ea50276e942b6f34f [2/2] tracing: Define is_signed_type() once
config: sh-allmodconfig (https://download.01.org/0day-ci/archive/20220825/202208250433.EVz5pZkB-lkp@xxxxxxxxx/config)
compiler: sh4-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/bvanassche/linux/commit/e50691460d5ea5a49b903e0ea50276e942b6f34f
git remote add bvanassche https://github.com/bvanassche/linux
git fetch --no-tags bvanassche tracing
git checkout e50691460d5ea5a49b903e0ea50276e942b6f34f
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=sh SHELL=/bin/bash drivers/net/

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

In file included from include/trace/define_trace.h:102,
from drivers/net/wireless/mediatek/mt7601u/trace.h:392,
from drivers/net/wireless/mediatek/mt7601u/trace.c:11:
>> include/linux/compiler.h:246:47: warning: ordered comparison of pointer with null pointer [-Wextra]
246 | #define is_signed_type(type) (((type)(-1)) <= (type)0)
| ^~
include/trace/trace_events.h:244:9: note: in definition of macro 'DECLARE_EVENT_CLASS'
244 | tstruct \
| ^~~~~~~
include/trace/trace_events.h:43:30: note: in expansion of macro 'PARAMS'
43 | PARAMS(tstruct), \
| ^~~~~~
drivers/net/wireless/mediatek/mt7601u/./trace.h:98:1: note: in expansion of macro 'TRACE_EVENT'
98 | TRACE_EVENT(mt_vend_req,
| ^~~~~~~~~~~
drivers/net/wireless/mediatek/mt7601u/./trace.h:102:9: note: in expansion of macro 'TP_STRUCT__entry'
102 | TP_STRUCT__entry(
| ^~~~~~~~~~~~~~~~
include/trace/stages/stage4_event_fields.h:11:22: note: in expansion of macro 'is_signed_type'
11 | .is_signed = is_signed_type(_type), .filter_type = _filter_type },
| ^~~~~~~~~~~~~~
include/trace/stages/stage4_event_fields.h:20:33: note: in expansion of macro '__field_ext'
20 | #define __field(type, item) __field_ext(type, item, FILTER_OTHER)
| ^~~~~~~~~~~
drivers/net/wireless/mediatek/mt7601u/./trace.h:105:56: note: in expansion of macro '__field'
105 | __field(u16, val) __field(u16, offset) __field(void*, buf)
| ^~~~~~~


vim +246 include/linux/compiler.h

241
242 /*
243 * Whether 'type' is a signed type or an unsigned type. Supports scalar types,
244 * bool and also pointer types.
245 */
> 246 #define is_signed_type(type) (((type)(-1)) <= (type)0)
247

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