On 06/11/2021 19:27, Arnaldo Carvalho de Melo wrote:

Em Sat, Oct 30, 2021 at 12:30:41AM +0800, John Garry escreveu:

quoted

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 <redacted>
Signed-off-by: John Garry <redacted>
--
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 :)

Thanks,
John

- Arnaldo
  

quoted

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