Re: [PATCH] perf tools: Enable warnings through HOSTCFLAGS

[Arnaldo Carvalho de Melo]

On November 15, 2021 12:53:33 PM GMT-03:00, John Garry <john.garry@xxxxxxxxxx> wrote:
>On 06/11/2021 19:27, Arnaldo Carvalho de Melo wrote:
>> Em Sat, Oct 30, 2021 at 12:30:41AM +0800, John Garry escreveu:
>>> The tools build system uses KBUILD_HOSTCFLAGS symbol for obvious purposes.
>>>
>>> However this is not set for anything under tools/
>>>
>>> As such, host tools apps built have no compiler warnings enabled.
>>>
>>> Declare HOSTCFLAGS for perf tools build, and also use that symbol in
>>> declaration of host_c_flags. HOSTCFLAGS comes from EXTRA_WARNINGS, which
>>> is independent of target platform/arch warning flags.
>>>
>>> Suggested-by: Jiri Olsa <jolsa@xxxxxxxxxx>
>>> Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
>>> --
>>> Using HOSTCFLAGS, as opposed to KBUILD_HOSTCFLAGS, is going opposite
>>> direction to commit 96f14fe738b6 ("kbuild: Rename HOSTCFLAGS to
>>> KBUILD_HOSTCFLAGS"), so would like further opinion from Laura and
>>> Masahiro.
>> 
>> Laura's redhat e-mail bouncedm updated it to her kernel.org one, Laura,
>> Masahiro, would you please comment? Jiri?
>
>Any opinion on this one? Shall I just resend ... ? or just apply it if 
>no one cares too much :)

I'll apply it now that everybody got enough time to review it . :-)

- Arnaldo
>
>Thanks,
>John
>
>> 
>> - Arnaldo
>>   
>>> diff --git a/tools/build/Build.include b/tools/build/Build.include
>>> index 2cf3b1bde86e..c2a95ab47379 100644
>>> --- a/tools/build/Build.include
>>> +++ b/tools/build/Build.include
>>> @@ -99,7 +99,7 @@ cxx_flags = -Wp,-MD,$(depfile) -Wp,-MT,$@ $(CXXFLAGS) -D"BUILD_STR(s)=\#s" $(CXX
>>>   ###
>>>   ## HOSTCC C flags
>>>   
>>> -host_c_flags = -Wp,-MD,$(depfile) -Wp,-MT,$@ $(KBUILD_HOSTCFLAGS) -D"BUILD_STR(s)=\#s" $(HOSTCFLAGS_$(basetarget).o) $(HOSTCFLAGS_$(obj))
>>> +host_c_flags = -Wp,-MD,$(depfile) -Wp,-MT,$@ $(HOSTCFLAGS) -D"BUILD_STR(s)=\#s" $(HOSTCFLAGS_$(basetarget).o) $(HOSTCFLAGS_$(obj))
>>>   
>>>   # output directory for tests below
>>>   TMPOUT = .tmp_$$$$
>>> diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
>>> index 4a9baed28f2e..9b95ba09657f 100644
>>> --- a/tools/perf/Makefile.config
>>> +++ b/tools/perf/Makefile.config
>>> @@ -17,6 +17,7 @@ detected     = $(shell echo "$(1)=y"       >> $(OUTPUT).config-detected)
>>>   detected_var = $(shell echo "$(1)=$($(1))" >> $(OUTPUT).config-detected)
>>>   
>>>   CFLAGS := $(EXTRA_CFLAGS) $(filter-out -Wnested-externs,$(EXTRA_WARNINGS))
>>> +HOSTCFLAGS := $(filter-out -Wnested-externs,$(EXTRA_WARNINGS))
>>>   
>>>   include $(srctree)/tools/scripts/Makefile.arch
>>>   
>>> @@ -211,6 +212,7 @@ endif
>>>   ifneq ($(WERROR),0)
>>>     CORE_CFLAGS += -Werror
>>>     CXXFLAGS += -Werror
>>> +  HOSTCFLAGS += -Werror
>>>   endif
>>>   
>>>   ifndef DEBUG
>>> @@ -292,6 +294,9 @@ CXXFLAGS += -ggdb3
>>>   CXXFLAGS += -funwind-tables
>>>   CXXFLAGS += -Wno-strict-aliasing
>>>   
>>> +HOSTCFLAGS += -Wall
>>> +HOSTCFLAGS += -Wextra
>>> +
>>>   # Enforce a non-executable stack, as we may regress (again) in the future by
>>>   # adding assembler files missing the .GNU-stack linker note.
>>>   LDFLAGS += -Wl,-z,noexecstack
>>> diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
>>> index a3966f290297..8ca656aa8b06 100644
>>> --- a/tools/perf/Makefile.perf
>>> +++ b/tools/perf/Makefile.perf
>>> @@ -226,7 +226,7 @@ else
>>>   endif
>>>   
>>>   export srctree OUTPUT RM CC CXX LD AR CFLAGS CXXFLAGS V BISON FLEX AWK
>>> -export HOSTCC HOSTLD HOSTAR
>>> +export HOSTCC HOSTLD HOSTAR HOSTCFLAGS
>>>   
>>>   include $(srctree)/tools/build/Makefile.include
>>>   
>>> -- 
>>> 2.17.1
>> 
>