Date:   Mon, 15 Nov 2021 22:10:48 +0100
From:   Jiri Olsa <jolsa@redhat.com>
To:     Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
Cc:     John Garry <john.garry@huawei.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        masahiroy@kernel.org, Laura Abbott <labbott@kernel.org>,
        peterz@infradead.org, mingo@redhat.com,
        alexander.shishkin@linux.intel.com, namhyung@kernel.org,
        linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
        irogers@google.com
Subject: Re: [PATCH] perf tools: Enable warnings through HOSTCFLAGS
Message-ID: <YZLM2BmFo+cK4B4J@krava>
References: <1635525041-151876-1-git-send-email-john.garry@huawei.com>
 <YYbXMd3N4+aXYLTJ@kernel.org>
 <591edce2-5aaa-22bc-6fd3-5a247f623eb3@huawei.com>
 <239840A9-F713-4FED-B638-14D6B91FBBF2@gmail.com>
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In-Reply-To: <239840A9-F713-4FED-B638-14D6B91FBBF2@gmail.com>
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On Mon, Nov 15, 2021 at 02:44:59PM -0300, Arnaldo Carvalho de Melo wrote:
> 
> 
> On November 15, 2021 12:53:33 PM GMT-03:00, John Garry <john.garry@huawei.com> 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@redhat.com>
> >>> Signed-off-by: John Garry <john.garry@huawei.com>
> >>> --
> >>> 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 . :-)

sorry, overlooked this one, looks good

Acked-by: Jiri Olsa <jolsa@redhat.com>

thanks,
jirka

> 
> - 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
> >> 
> >
>