[PATCH 0/7] kbuild: remove cc-option-yn

[PATCH 0/7] kbuild: remove cc-option-yn

[Nick Desaulniers]

cc-option-yn can be replaced with cc-option. ie.
Checking for support:
ifeq ($(call cc-option-yn,$(FLAG)),y)
becomes:
ifneq ($(call cc-option,$(FLAG)),)

Checking for lack of support:
ifeq ($(call cc-option-yn,$(FLAG)),n)
becomes:
ifeq ($(call cc-option,$(FLAG)),)

This allows us to remove cc-option-yn. Do so, and update the
docs.

Base is linux-next.

Nick Desaulniers (7):
  MIPS: replace cc-option-yn uses with cc-option
  s390: replace cc-option-yn uses with cc-option
  powerpc: replace cc-option-yn uses with cc-option
  arc: replace cc-option-yn uses with cc-option
  x86: remove cc-option-yn test for -mtune=
  Makefile: replace cc-option-yn uses with cc-option
  kbuild: remove cc-option-yn, update Docs

 Documentation/kbuild/makefiles.rst | 22 ++++++---------
 Makefile                           |  2 +-
 arch/arc/Makefile                  |  3 +-
 arch/mips/Makefile                 | 44 +++++++++++++++---------------
 arch/mips/sgi-ip22/Platform        |  4 +--
 arch/powerpc/Makefile              | 12 ++++----
 arch/powerpc/boot/Makefile         |  5 +---
 arch/s390/Makefile                 | 14 +++++-----
 arch/x86/Makefile_32.cpu           |  6 ----
 scripts/Makefile.compiler          |  5 ----
 10 files changed, 49 insertions(+), 68 deletions(-)

-- 
2.33.0.rc1.237.g0d66db33f3-goog

[PATCH 1/7] MIPS: replace cc-option-yn uses with cc-option

[Nick Desaulniers]

cc-option-yn can be replaced with cc-option. ie.
Checking for support:
ifeq ($(call cc-option-yn,$(FLAG)),y)
becomes:
ifneq ($(call cc-option,$(FLAG)),)

Checking for lack of support:
ifeq ($(call cc-option-yn,$(FLAG)),n)
becomes:
ifeq ($(call cc-option,$(FLAG)),)

This allows us to pursue removing cc-option-yn.

Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: linux-mips@vger.kernel.org
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
 arch/mips/Makefile          | 44 ++++++++++++++++++-------------------
 arch/mips/sgi-ip22/Platform |  4 ++--
 2 files changed, 24 insertions(+), 24 deletions(-)

diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index ea3cd080a1c7..f4b9850f17fa 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -58,9 +58,7 @@ endif
 
 ifdef CONFIG_FUNCTION_GRAPH_TRACER
   ifndef KBUILD_MCOUNT_RA_ADDRESS
-    ifeq ($(call cc-option-yn,-mmcount-ra-address), y)
-      cflags-y += -mmcount-ra-address -DKBUILD_MCOUNT_RA_ADDRESS
-    endif
+    cflags-y += $(call cc-option,-mmcount-ra-address -DKBUILD_MCOUNT_RA_ADDRESS)
   endif
 endif
 cflags-y += $(call cc-option, -mno-check-zero-division)
@@ -208,31 +206,33 @@ cflags-$(CONFIG_CPU_DADDI_WORKAROUNDS)	+= $(call cc-option,-mno-daddi,)
 # been fixed properly.
 mips-cflags				:= $(cflags-y)
 ifeq ($(CONFIG_CPU_HAS_SMARTMIPS),y)
-smartmips-ase				:= $(call cc-option-yn,$(mips-cflags) -msmartmips)
-cflags-$(smartmips-ase)			+= -msmartmips -Wa,--no-warn
+cflags-y	+= $(call cc-option,-msmartmips -Wa$(comma)--no-warn)
 endif
 ifeq ($(CONFIG_CPU_MICROMIPS),y)
-micromips-ase				:= $(call cc-option-yn,$(mips-cflags) -mmicromips)
-cflags-$(micromips-ase)			+= -mmicromips
+cflags-y	+= $(call cc-option,-mmicromips)
 endif
 ifeq ($(CONFIG_CPU_HAS_MSA),y)
-toolchain-msa				:= $(call cc-option-yn,$(mips-cflags) -mhard-float -mfp64 -Wa$(comma)-mmsa)
-cflags-$(toolchain-msa)			+= -DTOOLCHAIN_SUPPORTS_MSA
+ifneq ($(call cc-option,-mhard-float -mfp64 -Wa$(comma)-mmsa),)
+cflags-y	+= -DTOOLCHAIN_SUPPORTS_MSA
+endif
+endif
+ifneq ($(call cc-option,-mvirt),)
+cflags-y	+= -DTOOLCHAIN_SUPPORTS_VIRT
 endif
-toolchain-virt				:= $(call cc-option-yn,$(mips-cflags) -mvirt)
-cflags-$(toolchain-virt)		+= -DTOOLCHAIN_SUPPORTS_VIRT
 # For -mmicromips, use -Wa,-fatal-warnings to catch unsupported -mxpa which
 # only warns
-xpa-cflags-y				:= $(mips-cflags)
-xpa-cflags-$(micromips-ase)		+= -mmicromips -Wa$(comma)-fatal-warnings
-toolchain-xpa				:= $(call cc-option-yn,$(xpa-cflags-y) -mxpa)
-cflags-$(toolchain-xpa)			+= -DTOOLCHAIN_SUPPORTS_XPA
-toolchain-crc				:= $(call cc-option-yn,$(mips-cflags) -Wa$(comma)-mcrc)
-cflags-$(toolchain-crc)			+= -DTOOLCHAIN_SUPPORTS_CRC
-toolchain-dsp				:= $(call cc-option-yn,$(mips-cflags) -Wa$(comma)-mdsp)
-cflags-$(toolchain-dsp)			+= -DTOOLCHAIN_SUPPORTS_DSP
-toolchain-ginv				:= $(call cc-option-yn,$(mips-cflags) -Wa$(comma)-mginv)
-cflags-$(toolchain-ginv)		+= -DTOOLCHAIN_SUPPORTS_GINV
+ifneq ($(call cc-option,-mmicromips -Wa$(comma)-fatal-warnings -mxpa),)
+cflags-y	+= -DTOOLCHAIN_SUPPORTS_XPA
+endif
+ifneq ($(call cc-option,-Wa$(comma)-mcrc),)
+cflags-y	+= -DTOOLCHAIN_SUPPORTS_CRC
+endif
+ifneq ($(call cc-option,-Wa$(comma)-mdsp),)
+cflags-y	+= -DTOOLCHAIN_SUPPORTS_DSP
+endif
+ifneq ($(call cc-option,-Wa$(comma)-mginv),)
+cflags-y	+= -DTOOLCHAIN_SUPPORTS_GINV
+endif
 
 #
 # Firmware support
@@ -277,7 +277,7 @@ ifdef CONFIG_64BIT
     endif
   endif
 
-  ifeq ($(KBUILD_SYM32)$(call cc-option-yn,-msym32), yy)
+  ifeq ($(KBUILD_SYM32)$(call cc-option,-msym32), y-msym32)
     cflags-y += -msym32 -DKBUILD_64BIT_SYM32
   else
     ifeq ($(CONFIG_CPU_DADDI_WORKAROUNDS), y)
diff --git a/arch/mips/sgi-ip22/Platform b/arch/mips/sgi-ip22/Platform
index 62fa30bb959e..fd8f1d01c867 100644
--- a/arch/mips/sgi-ip22/Platform
+++ b/arch/mips/sgi-ip22/Platform
@@ -24,8 +24,8 @@ endif
 # Simplified: what IP22 does at 128MB+ in ksegN, IP28 does at 512MB+ in xkphys
 #
 ifdef CONFIG_SGI_IP28
-  ifeq ($(call cc-option-yn,-march=r10000 -mr10k-cache-barrier=store), n)
-      $(error gcc doesn't support needed option -mr10k-cache-barrier=store)
+  ifeq ($(call cc-option,-march=r10000 -mr10k-cache-barrier=store),)
+      $(error $(CC) doesn't support needed option -mr10k-cache-barrier=store)
   endif
 endif
 cflags-$(CONFIG_SGI_IP28)	+= -mr10k-cache-barrier=store -I$(srctree)/arch/mips/include/asm/mach-ip28
-- 
2.33.0.rc1.237.g0d66db33f3-goog

Re: [PATCH 1/7] MIPS: replace cc-option-yn uses with cc-option

[Nathan Chancellor]

On 8/16/2021 5:21 PM, 'Nick Desaulniers' via Clang Built Linux wrote:
> cc-option-yn can be replaced with cc-option. ie.
> Checking for support:
> ifeq ($(call cc-option-yn,$(FLAG)),y)
> becomes:
> ifneq ($(call cc-option,$(FLAG)),)
> 
> Checking for lack of support:
> ifeq ($(call cc-option-yn,$(FLAG)),n)
> becomes:
> ifeq ($(call cc-option,$(FLAG)),)
> 
> This allows us to pursue removing cc-option-yn.
> 
> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> Cc: linux-mips@vger.kernel.org
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> ---
>   arch/mips/Makefile          | 44 ++++++++++++++++++-------------------
>   arch/mips/sgi-ip22/Platform |  4 ++--
>   2 files changed, 24 insertions(+), 24 deletions(-)
> 
> diff --git a/arch/mips/Makefile b/arch/mips/Makefile
> index ea3cd080a1c7..f4b9850f17fa 100644
> --- a/arch/mips/Makefile
> +++ b/arch/mips/Makefile
> @@ -58,9 +58,7 @@ endif
>   
>   ifdef CONFIG_FUNCTION_GRAPH_TRACER
>     ifndef KBUILD_MCOUNT_RA_ADDRESS
> -    ifeq ($(call cc-option-yn,-mmcount-ra-address), y)
> -      cflags-y += -mmcount-ra-address -DKBUILD_MCOUNT_RA_ADDRESS
> -    endif
> +    cflags-y += $(call cc-option,-mmcount-ra-address -DKBUILD_MCOUNT_RA_ADDRESS)
>     endif
>   endif
>   cflags-y += $(call cc-option, -mno-check-zero-division)
> @@ -208,31 +206,33 @@ cflags-$(CONFIG_CPU_DADDI_WORKAROUNDS)	+= $(call cc-option,-mno-daddi,)
>   # been fixed properly.
>   mips-cflags				:= $(cflags-y)
>   ifeq ($(CONFIG_CPU_HAS_SMARTMIPS),y)
> -smartmips-ase				:= $(call cc-option-yn,$(mips-cflags) -msmartmips)
> -cflags-$(smartmips-ase)			+= -msmartmips -Wa,--no-warn
> +cflags-y	+= $(call cc-option,-msmartmips -Wa$(comma)--no-warn)

I do not think this diff and most of the ones that follow are 
equivalent, as you are no longer including the previously checked flags 
in the cc-option invocation, which could change the result (options that 
follow may depend on a prior selected flag).

I think that as long as you add $(cflags-y) to all of the cc-option 
tests, it should be fine. I guess cflags-y could be eliminated but it 
looks like this variable exists so that the flags can be added to both 
KBUILD_CFLAGS and KBUILD_AFLAGS at the same time so removing it would 
duplicate a lot of things.

>   endif
>   ifeq ($(CONFIG_CPU_MICROMIPS),y)
> -micromips-ase				:= $(call cc-option-yn,$(mips-cflags) -mmicromips)
> -cflags-$(micromips-ase)			+= -mmicromips
> +cflags-y	+= $(call cc-option,-mmicromips)
>   endif
>   ifeq ($(CONFIG_CPU_HAS_MSA),y)
> -toolchain-msa				:= $(call cc-option-yn,$(mips-cflags) -mhard-float -mfp64 -Wa$(comma)-mmsa)
> -cflags-$(toolchain-msa)			+= -DTOOLCHAIN_SUPPORTS_MSA
> +ifneq ($(call cc-option,-mhard-float -mfp64 -Wa$(comma)-mmsa),)
> +cflags-y	+= -DTOOLCHAIN_SUPPORTS_MSA
> +endif
> +endif
> +ifneq ($(call cc-option,-mvirt),)
> +cflags-y	+= -DTOOLCHAIN_SUPPORTS_VIRT
>   endif
> -toolchain-virt				:= $(call cc-option-yn,$(mips-cflags) -mvirt)
> -cflags-$(toolchain-virt)		+= -DTOOLCHAIN_SUPPORTS_VIRT
>   # For -mmicromips, use -Wa,-fatal-warnings to catch unsupported -mxpa which
>   # only warns
> -xpa-cflags-y				:= $(mips-cflags)
> -xpa-cflags-$(micromips-ase)		+= -mmicromips -Wa$(comma)-fatal-warnings
> -toolchain-xpa				:= $(call cc-option-yn,$(xpa-cflags-y) -mxpa)
> -cflags-$(toolchain-xpa)			+= -DTOOLCHAIN_SUPPORTS_XPA
> -toolchain-crc				:= $(call cc-option-yn,$(mips-cflags) -Wa$(comma)-mcrc)
> -cflags-$(toolchain-crc)			+= -DTOOLCHAIN_SUPPORTS_CRC
> -toolchain-dsp				:= $(call cc-option-yn,$(mips-cflags) -Wa$(comma)-mdsp)
> -cflags-$(toolchain-dsp)			+= -DTOOLCHAIN_SUPPORTS_DSP
> -toolchain-ginv				:= $(call cc-option-yn,$(mips-cflags) -Wa$(comma)-mginv)
> -cflags-$(toolchain-ginv)		+= -DTOOLCHAIN_SUPPORTS_GINV
> +ifneq ($(call cc-option,-mmicromips -Wa$(comma)-fatal-warnings -mxpa),)
> +cflags-y	+= -DTOOLCHAIN_SUPPORTS_XPA
> +endif
> +ifneq ($(call cc-option,-Wa$(comma)-mcrc),)
> +cflags-y	+= -DTOOLCHAIN_SUPPORTS_CRC
> +endif
> +ifneq ($(call cc-option,-Wa$(comma)-mdsp),)
> +cflags-y	+= -DTOOLCHAIN_SUPPORTS_DSP
> +endif
> +ifneq ($(call cc-option,-Wa$(comma)-mginv),)
> +cflags-y	+= -DTOOLCHAIN_SUPPORTS_GINV
> +endif
>   
>   #
>   # Firmware support
> @@ -277,7 +277,7 @@ ifdef CONFIG_64BIT
>       endif
>     endif
>   
> -  ifeq ($(KBUILD_SYM32)$(call cc-option-yn,-msym32), yy)
> +  ifeq ($(KBUILD_SYM32)$(call cc-option,-msym32), y-msym32)
>       cflags-y += -msym32 -DKBUILD_64BIT_SYM32
>     else
>       ifeq ($(CONFIG_CPU_DADDI_WORKAROUNDS), y)
> diff --git a/arch/mips/sgi-ip22/Platform b/arch/mips/sgi-ip22/Platform
> index 62fa30bb959e..fd8f1d01c867 100644
> --- a/arch/mips/sgi-ip22/Platform
> +++ b/arch/mips/sgi-ip22/Platform
> @@ -24,8 +24,8 @@ endif
>   # Simplified: what IP22 does at 128MB+ in ksegN, IP28 does at 512MB+ in xkphys
>   #
>   ifdef CONFIG_SGI_IP28
> -  ifeq ($(call cc-option-yn,-march=r10000 -mr10k-cache-barrier=store), n)
> -      $(error gcc doesn't support needed option -mr10k-cache-barrier=store)
> +  ifeq ($(call cc-option,-march=r10000 -mr10k-cache-barrier=store),)
> +      $(error $(CC) doesn't support needed option -mr10k-cache-barrier=store)

Heh :)

>     endif
>   endif
>   cflags-$(CONFIG_SGI_IP28)	+= -mr10k-cache-barrier=store -I$(srctree)/arch/mips/include/asm/mach-ip28
> 

[PATCH 2/7] s390: replace cc-option-yn uses with cc-option

[Nick Desaulniers]

cc-option-yn can be replaced with cc-option. ie.
Checking for support:
ifeq ($(call cc-option-yn,$(FLAG)),y)
becomes:
ifneq ($(call cc-option,$(FLAG)),)

Checking for lack of support:
ifeq ($(call cc-option-yn,$(FLAG)),n)
becomes:
ifeq ($(call cc-option,$(FLAG)),)

This allows us to pursue removing cc-option-yn.

Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
 arch/s390/Makefile | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/arch/s390/Makefile b/arch/s390/Makefile
index 17dc4f1ac4fa..a3cf33ad009f 100644
--- a/arch/s390/Makefile
+++ b/arch/s390/Makefile
@@ -70,7 +70,7 @@ cflags-y += -Wa,-I$(srctree)/arch/$(ARCH)/include
 #
 cflags-$(CONFIG_FRAME_POINTER) += -fno-optimize-sibling-calls
 
-ifeq ($(call cc-option-yn,-mpacked-stack -mbackchain -msoft-float),y)
+ifneq ($(call cc-option,-mpacked-stack -mbackchain -msoft-float),)
 cflags-$(CONFIG_PACK_STACK)  += -mpacked-stack -D__PACK_STACK
 aflags-$(CONFIG_PACK_STACK)  += -D__PACK_STACK
 endif
@@ -78,22 +78,22 @@ endif
 KBUILD_AFLAGS_DECOMPRESSOR += $(aflags-y)
 KBUILD_CFLAGS_DECOMPRESSOR += $(cflags-y)
 
-ifeq ($(call cc-option-yn,-mstack-size=8192 -mstack-guard=128),y)
+ifneq ($(call cc-option,-mstack-size=8192 -mstack-guard=128),)
 cflags-$(CONFIG_CHECK_STACK) += -mstack-size=$(STACK_SIZE)
-ifneq ($(call cc-option-yn,-mstack-size=8192),y)
+ifeq ($(call cc-option,-mstack-size=8192),)
 cflags-$(CONFIG_CHECK_STACK) += -mstack-guard=$(CONFIG_STACK_GUARD)
 endif
 endif
 
 ifdef CONFIG_WARN_DYNAMIC_STACK
-  ifeq ($(call cc-option-yn,-mwarn-dynamicstack),y)
+  ifneq ($(call cc-option,-mwarn-dynamicstack),)
     KBUILD_CFLAGS += -mwarn-dynamicstack
     KBUILD_CFLAGS_DECOMPRESSOR += -mwarn-dynamicstack
   endif
 endif
 
 ifdef CONFIG_EXPOLINE
-  ifeq ($(call cc-option-yn,$(CC_FLAGS_MARCH) -mindirect-branch=thunk),y)
+  ifneq ($(call cc-option,$(CC_FLAGS_MARCH) -mindirect-branch=thunk),)
     CC_FLAGS_EXPOLINE := -mindirect-branch=thunk
     CC_FLAGS_EXPOLINE += -mfunction-return=thunk
     CC_FLAGS_EXPOLINE += -mindirect-branch-table
@@ -104,10 +104,10 @@ ifdef CONFIG_EXPOLINE
 endif
 
 ifdef CONFIG_FUNCTION_TRACER
-  ifeq ($(call cc-option-yn,-mfentry -mnop-mcount),n)
+  ifeq ($(call cc-option,-mfentry -mnop-mcount),)
     # make use of hotpatch feature if the compiler supports it
     cc_hotpatch	:= -mhotpatch=0,3
-    ifeq ($(call cc-option-yn,$(cc_hotpatch)),y)
+    ifneq ($(call cc-option,$(cc_hotpatch)),)
       CC_FLAGS_FTRACE := $(cc_hotpatch)
       KBUILD_AFLAGS	+= -DCC_USING_HOTPATCH
       KBUILD_CFLAGS	+= -DCC_USING_HOTPATCH
-- 
2.33.0.rc1.237.g0d66db33f3-goog

Re: [PATCH 2/7] s390: replace cc-option-yn uses with cc-option

[Nathan Chancellor]

On 8/16/2021 5:21 PM, 'Nick Desaulniers' via Clang Built Linux wrote:
> cc-option-yn can be replaced with cc-option. ie.
> Checking for support:
> ifeq ($(call cc-option-yn,$(FLAG)),y)
> becomes:
> ifneq ($(call cc-option,$(FLAG)),)
> 
> Checking for lack of support:
> ifeq ($(call cc-option-yn,$(FLAG)),n)
> becomes:
> ifeq ($(call cc-option,$(FLAG)),)
> 
> This allows us to pursue removing cc-option-yn.
> 
> Cc: Heiko Carstens <hca@linux.ibm.com>
> Cc: Vasily Gorbik <gor@linux.ibm.com>
> Cc: Christian Borntraeger <borntraeger@de.ibm.com>
> Cc: linux-s390@vger.kernel.org
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

> ---
>   arch/s390/Makefile | 14 +++++++-------
>   1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/s390/Makefile b/arch/s390/Makefile
> index 17dc4f1ac4fa..a3cf33ad009f 100644
> --- a/arch/s390/Makefile
> +++ b/arch/s390/Makefile
> @@ -70,7 +70,7 @@ cflags-y += -Wa,-I$(srctree)/arch/$(ARCH)/include
>   #
>   cflags-$(CONFIG_FRAME_POINTER) += -fno-optimize-sibling-calls
>   
> -ifeq ($(call cc-option-yn,-mpacked-stack -mbackchain -msoft-float),y)
> +ifneq ($(call cc-option,-mpacked-stack -mbackchain -msoft-float),)
>   cflags-$(CONFIG_PACK_STACK)  += -mpacked-stack -D__PACK_STACK
>   aflags-$(CONFIG_PACK_STACK)  += -D__PACK_STACK
>   endif
> @@ -78,22 +78,22 @@ endif
>   KBUILD_AFLAGS_DECOMPRESSOR += $(aflags-y)
>   KBUILD_CFLAGS_DECOMPRESSOR += $(cflags-y)
>   
> -ifeq ($(call cc-option-yn,-mstack-size=8192 -mstack-guard=128),y)
> +ifneq ($(call cc-option,-mstack-size=8192 -mstack-guard=128),)
>   cflags-$(CONFIG_CHECK_STACK) += -mstack-size=$(STACK_SIZE)
> -ifneq ($(call cc-option-yn,-mstack-size=8192),y)
> +ifeq ($(call cc-option,-mstack-size=8192),)
>   cflags-$(CONFIG_CHECK_STACK) += -mstack-guard=$(CONFIG_STACK_GUARD)
>   endif
>   endif
>   
>   ifdef CONFIG_WARN_DYNAMIC_STACK
> -  ifeq ($(call cc-option-yn,-mwarn-dynamicstack),y)
> +  ifneq ($(call cc-option,-mwarn-dynamicstack),)
>       KBUILD_CFLAGS += -mwarn-dynamicstack
>       KBUILD_CFLAGS_DECOMPRESSOR += -mwarn-dynamicstack
>     endif
>   endif
>   
>   ifdef CONFIG_EXPOLINE
> -  ifeq ($(call cc-option-yn,$(CC_FLAGS_MARCH) -mindirect-branch=thunk),y)
> +  ifneq ($(call cc-option,$(CC_FLAGS_MARCH) -mindirect-branch=thunk),)
>       CC_FLAGS_EXPOLINE := -mindirect-branch=thunk
>       CC_FLAGS_EXPOLINE += -mfunction-return=thunk
>       CC_FLAGS_EXPOLINE += -mindirect-branch-table
> @@ -104,10 +104,10 @@ ifdef CONFIG_EXPOLINE
>   endif
>   
>   ifdef CONFIG_FUNCTION_TRACER
> -  ifeq ($(call cc-option-yn,-mfentry -mnop-mcount),n)
> +  ifeq ($(call cc-option,-mfentry -mnop-mcount),)
>       # make use of hotpatch feature if the compiler supports it
>       cc_hotpatch	:= -mhotpatch=0,3
> -    ifeq ($(call cc-option-yn,$(cc_hotpatch)),y)
> +    ifneq ($(call cc-option,$(cc_hotpatch)),)
>         CC_FLAGS_FTRACE := $(cc_hotpatch)
>         KBUILD_AFLAGS	+= -DCC_USING_HOTPATCH
>         KBUILD_CFLAGS	+= -DCC_USING_HOTPATCH
> 

Re: [PATCH 2/7] s390: replace cc-option-yn uses with cc-option

[Heiko Carstens]

On Mon, Aug 16, 2021 at 05:21:04PM -0700, Nick Desaulniers wrote:
> cc-option-yn can be replaced with cc-option. ie.
> Checking for support:
> ifeq ($(call cc-option-yn,$(FLAG)),y)
> becomes:
> ifneq ($(call cc-option,$(FLAG)),)
> 
> Checking for lack of support:
> ifeq ($(call cc-option-yn,$(FLAG)),n)
> becomes:
> ifeq ($(call cc-option,$(FLAG)),)
> 
> This allows us to pursue removing cc-option-yn.
> 
> Cc: Heiko Carstens <hca@linux.ibm.com>
> Cc: Vasily Gorbik <gor@linux.ibm.com>
> Cc: Christian Borntraeger <borntraeger@de.ibm.com>
> Cc: linux-s390@vger.kernel.org
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> ---
>  arch/s390/Makefile | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)

Acked-by: Heiko Carstens <hca@linux.ibm.com>

Re: [PATCH 2/7] s390: replace cc-option-yn uses with cc-option

[Masahiro Yamada]

On Tue, Aug 24, 2021 at 2:43 AM Heiko Carstens <hca@linux.ibm.com> wrote:
>
> On Mon, Aug 16, 2021 at 05:21:04PM -0700, Nick Desaulniers wrote:
> > cc-option-yn can be replaced with cc-option. ie.
> > Checking for support:
> > ifeq ($(call cc-option-yn,$(FLAG)),y)
> > becomes:
> > ifneq ($(call cc-option,$(FLAG)),)
> >
> > Checking for lack of support:
> > ifeq ($(call cc-option-yn,$(FLAG)),n)
> > becomes:
> > ifeq ($(call cc-option,$(FLAG)),)
> >
> > This allows us to pursue removing cc-option-yn.
> >
> > Cc: Heiko Carstens <hca@linux.ibm.com>
> > Cc: Vasily Gorbik <gor@linux.ibm.com>
> > Cc: Christian Borntraeger <borntraeger@de.ibm.com>
> > Cc: linux-s390@vger.kernel.org
> > Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> > ---
> >  arch/s390/Makefile | 14 +++++++-------
> >  1 file changed, 7 insertions(+), 7 deletions(-)
>
> Acked-by: Heiko Carstens <hca@linux.ibm.com>

Applied to linux-kbuild.


-- 
Best Regards
Masahiro Yamada

[PATCH 3/7] powerpc: replace cc-option-yn uses with cc-option

[Nick Desaulniers]

cc-option-yn can be replaced with cc-option. ie.
Checking for support:
ifeq ($(call cc-option-yn,$(FLAG)),y)
becomes:
ifneq ($(call cc-option,$(FLAG)),)

Checking for lack of support:
ifeq ($(call cc-option-yn,$(FLAG)),n)
becomes:
ifeq ($(call cc-option,$(FLAG)),)

This allows us to pursue removing cc-option-yn.

Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
 arch/powerpc/Makefile      | 12 ++++++------
 arch/powerpc/boot/Makefile |  5 +----
 2 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 9aaf1abbc641..85e224536cf7 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -12,12 +12,12 @@
 # Rewritten by Cort Dougan and Paul Mackerras
 #
 
-HAS_BIARCH	:= $(call cc-option-yn, -m32)
+HAS_BIARCH	:= $(call cc-option,-m32)
 
 # Set default 32 bits cross compilers for vdso and boot wrapper
 CROSS32_COMPILE ?=
 
-ifeq ($(HAS_BIARCH),y)
+ifeq ($(HAS_BIARCH),-m32)
 ifeq ($(CROSS32_COMPILE),)
 ifdef CONFIG_PPC32
 # These options will be overridden by any -mcpu option that the CPU
@@ -107,7 +107,7 @@ cflags-$(CONFIG_CPU_LITTLE_ENDIAN)	+= -mlittle-endian
 aflags-$(CONFIG_CPU_BIG_ENDIAN)		+= $(call cc-option,-mbig-endian)
 aflags-$(CONFIG_CPU_LITTLE_ENDIAN)	+= -mlittle-endian
 
-ifeq ($(HAS_BIARCH),y)
+ifeq ($(HAS_BIARCH),-m32)
 KBUILD_CFLAGS	+= -m$(BITS)
 KBUILD_AFLAGS	+= -m$(BITS) -Wl,-a$(BITS)
 KBUILD_LDFLAGS	+= -m elf$(BITS)$(LDEMULATION)
@@ -125,7 +125,9 @@ LDFLAGS_vmlinux-$(CONFIG_RELOCATABLE) := -pie
 LDFLAGS_vmlinux	:= $(LDFLAGS_vmlinux-y)
 
 ifdef CONFIG_PPC64
-ifeq ($(call cc-option-yn,-mcmodel=medium),y)
+ifeq ($(call cc-option,-mcmodel=medium),)
+	export NO_MINIMAL_TOC := -mno-minimal-toc
+else
 	# -mcmodel=medium breaks modules because it uses 32bit offsets from
 	# the TOC pointer to create pointers where possible. Pointers into the
 	# percpu data area are created by this method.
@@ -135,8 +137,6 @@ ifeq ($(call cc-option-yn,-mcmodel=medium),y)
 	# kernel percpu data space (starting with 0xc...). We need a full
 	# 64bit relocation for this to work, hence -mcmodel=large.
 	KBUILD_CFLAGS_MODULE += -mcmodel=large
-else
-	export NO_MINIMAL_TOC := -mno-minimal-toc
 endif
 endif
 
diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
index 10c0fb306f15..33e1de5d1c95 100644
--- a/arch/powerpc/boot/Makefile
+++ b/arch/powerpc/boot/Makefile
@@ -66,10 +66,7 @@ ifdef CONFIG_DEBUG_INFO
 BOOTCFLAGS	+= -g
 endif
 
-ifeq ($(call cc-option-yn, -fstack-protector),y)
-BOOTCFLAGS	+= -fno-stack-protector
-endif
-
+BOOTCFLAGS	+= $(call cc-option,-fstack-protector)
 BOOTCFLAGS	+= -I$(objtree)/$(obj) -I$(srctree)/$(obj)
 
 DTC_FLAGS	?= -p 1024
-- 
2.33.0.rc1.237.g0d66db33f3-goog

[PATCH 3/7] powerpc: replace cc-option-yn uses with cc-option

[Nick Desaulniers]

cc-option-yn can be replaced with cc-option. ie.
Checking for support:
ifeq ($(call cc-option-yn,$(FLAG)),y)
becomes:
ifneq ($(call cc-option,$(FLAG)),)

Checking for lack of support:
ifeq ($(call cc-option-yn,$(FLAG)),n)
becomes:
ifeq ($(call cc-option,$(FLAG)),)

This allows us to pursue removing cc-option-yn.

Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
 arch/powerpc/Makefile      | 12 ++++++------
 arch/powerpc/boot/Makefile |  5 +----
 2 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 9aaf1abbc641..85e224536cf7 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -12,12 +12,12 @@
 # Rewritten by Cort Dougan and Paul Mackerras
 #
 
-HAS_BIARCH	:= $(call cc-option-yn, -m32)
+HAS_BIARCH	:= $(call cc-option,-m32)
 
 # Set default 32 bits cross compilers for vdso and boot wrapper
 CROSS32_COMPILE ?=
 
-ifeq ($(HAS_BIARCH),y)
+ifeq ($(HAS_BIARCH),-m32)
 ifeq ($(CROSS32_COMPILE),)
 ifdef CONFIG_PPC32
 # These options will be overridden by any -mcpu option that the CPU
@@ -107,7 +107,7 @@ cflags-$(CONFIG_CPU_LITTLE_ENDIAN)	+= -mlittle-endian
 aflags-$(CONFIG_CPU_BIG_ENDIAN)		+= $(call cc-option,-mbig-endian)
 aflags-$(CONFIG_CPU_LITTLE_ENDIAN)	+= -mlittle-endian
 
-ifeq ($(HAS_BIARCH),y)
+ifeq ($(HAS_BIARCH),-m32)
 KBUILD_CFLAGS	+= -m$(BITS)
 KBUILD_AFLAGS	+= -m$(BITS) -Wl,-a$(BITS)
 KBUILD_LDFLAGS	+= -m elf$(BITS)$(LDEMULATION)
@@ -125,7 +125,9 @@ LDFLAGS_vmlinux-$(CONFIG_RELOCATABLE) := -pie
 LDFLAGS_vmlinux	:= $(LDFLAGS_vmlinux-y)
 
 ifdef CONFIG_PPC64
-ifeq ($(call cc-option-yn,-mcmodel=medium),y)
+ifeq ($(call cc-option,-mcmodel=medium),)
+	export NO_MINIMAL_TOC := -mno-minimal-toc
+else
 	# -mcmodel=medium breaks modules because it uses 32bit offsets from
 	# the TOC pointer to create pointers where possible. Pointers into the
 	# percpu data area are created by this method.
@@ -135,8 +137,6 @@ ifeq ($(call cc-option-yn,-mcmodel=medium),y)
 	# kernel percpu data space (starting with 0xc...). We need a full
 	# 64bit relocation for this to work, hence -mcmodel=large.
 	KBUILD_CFLAGS_MODULE += -mcmodel=large
-else
-	export NO_MINIMAL_TOC := -mno-minimal-toc
 endif
 endif
 
diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
index 10c0fb306f15..33e1de5d1c95 100644
--- a/arch/powerpc/boot/Makefile
+++ b/arch/powerpc/boot/Makefile
@@ -66,10 +66,7 @@ ifdef CONFIG_DEBUG_INFO
 BOOTCFLAGS	+= -g
 endif
 
-ifeq ($(call cc-option-yn, -fstack-protector),y)
-BOOTCFLAGS	+= -fno-stack-protector
-endif
-
+BOOTCFLAGS	+= $(call cc-option,-fstack-protector)
 BOOTCFLAGS	+= -I$(objtree)/$(obj) -I$(srctree)/$(obj)
 
 DTC_FLAGS	?= -p 1024
-- 
2.33.0.rc1.237.g0d66db33f3-goog

Re: [PATCH 3/7] powerpc: replace cc-option-yn uses with cc-option

[Nathan Chancellor]

On 8/16/2021 5:21 PM, 'Nick Desaulniers' via Clang Built Linux wrote:
> cc-option-yn can be replaced with cc-option. ie.
> Checking for support:
> ifeq ($(call cc-option-yn,$(FLAG)),y)
> becomes:
> ifneq ($(call cc-option,$(FLAG)),)
> 
> Checking for lack of support:
> ifeq ($(call cc-option-yn,$(FLAG)),n)
> becomes:
> ifeq ($(call cc-option,$(FLAG)),)
> 
> This allows us to pursue removing cc-option-yn.
> 
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: linuxppc-dev@lists.ozlabs.org
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> ---
>   arch/powerpc/Makefile      | 12 ++++++------
>   arch/powerpc/boot/Makefile |  5 +----
>   2 files changed, 7 insertions(+), 10 deletions(-)
> 
> diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
> index 9aaf1abbc641..85e224536cf7 100644
> --- a/arch/powerpc/Makefile
> +++ b/arch/powerpc/Makefile
> @@ -12,12 +12,12 @@
>   # Rewritten by Cort Dougan and Paul Mackerras
>   #
>   
> -HAS_BIARCH	:= $(call cc-option-yn, -m32)
> +HAS_BIARCH	:= $(call cc-option,-m32)
>   
>   # Set default 32 bits cross compilers for vdso and boot wrapper
>   CROSS32_COMPILE ?=
>   
> -ifeq ($(HAS_BIARCH),y)
> +ifeq ($(HAS_BIARCH),-m32)
>   ifeq ($(CROSS32_COMPILE),)
>   ifdef CONFIG_PPC32
>   # These options will be overridden by any -mcpu option that the CPU
> @@ -107,7 +107,7 @@ cflags-$(CONFIG_CPU_LITTLE_ENDIAN)	+= -mlittle-endian
>   aflags-$(CONFIG_CPU_BIG_ENDIAN)		+= $(call cc-option,-mbig-endian)
>   aflags-$(CONFIG_CPU_LITTLE_ENDIAN)	+= -mlittle-endian
>   
> -ifeq ($(HAS_BIARCH),y)
> +ifeq ($(HAS_BIARCH),-m32)
>   KBUILD_CFLAGS	+= -m$(BITS)
>   KBUILD_AFLAGS	+= -m$(BITS) -Wl,-a$(BITS)
>   KBUILD_LDFLAGS	+= -m elf$(BITS)$(LDEMULATION)
> @@ -125,7 +125,9 @@ LDFLAGS_vmlinux-$(CONFIG_RELOCATABLE) := -pie
>   LDFLAGS_vmlinux	:= $(LDFLAGS_vmlinux-y)
>   
>   ifdef CONFIG_PPC64
> -ifeq ($(call cc-option-yn,-mcmodel=medium),y)
> +ifeq ($(call cc-option,-mcmodel=medium),)
> +	export NO_MINIMAL_TOC := -mno-minimal-toc
> +else
>   	# -mcmodel=medium breaks modules because it uses 32bit offsets from
>   	# the TOC pointer to create pointers where possible. Pointers into the
>   	# percpu data area are created by this method.
> @@ -135,8 +137,6 @@ ifeq ($(call cc-option-yn,-mcmodel=medium),y)
>   	# kernel percpu data space (starting with 0xc...). We need a full
>   	# 64bit relocation for this to work, hence -mcmodel=large.
>   	KBUILD_CFLAGS_MODULE += -mcmodel=large
> -else
> -	export NO_MINIMAL_TOC := -mno-minimal-toc
>   endif
>   endif
>   
> diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
> index 10c0fb306f15..33e1de5d1c95 100644
> --- a/arch/powerpc/boot/Makefile
> +++ b/arch/powerpc/boot/Makefile
> @@ -66,10 +66,7 @@ ifdef CONFIG_DEBUG_INFO
>   BOOTCFLAGS	+= -g
>   endif
>   
> -ifeq ($(call cc-option-yn, -fstack-protector),y)
> -BOOTCFLAGS	+= -fno-stack-protector
> -endif
> -
> +BOOTCFLAGS	+= $(call cc-option,-fstack-protector)

This was previously disabling the stack protector but now it is enabling 
it. Just remove the ifeq conditional altogether as the kernel assumes 
-fno-stack-protector is always supported after commit 893ab00439a4 
("kbuild: remove cc-option test of -fno-stack-protector").

>   BOOTCFLAGS	+= -I$(objtree)/$(obj) -I$(srctree)/$(obj)
>   
>   DTC_FLAGS	?= -p 1024
> 

Re: [PATCH 3/7] powerpc: replace cc-option-yn uses with cc-option

[Nathan Chancellor]

On 8/16/2021 5:21 PM, 'Nick Desaulniers' via Clang Built Linux wrote:
> cc-option-yn can be replaced with cc-option. ie.
> Checking for support:
> ifeq ($(call cc-option-yn,$(FLAG)),y)
> becomes:
> ifneq ($(call cc-option,$(FLAG)),)
> 
> Checking for lack of support:
> ifeq ($(call cc-option-yn,$(FLAG)),n)
> becomes:
> ifeq ($(call cc-option,$(FLAG)),)
> 
> This allows us to pursue removing cc-option-yn.
> 
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: linuxppc-dev@lists.ozlabs.org
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> ---
>   arch/powerpc/Makefile      | 12 ++++++------
>   arch/powerpc/boot/Makefile |  5 +----
>   2 files changed, 7 insertions(+), 10 deletions(-)
> 
> diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
> index 9aaf1abbc641..85e224536cf7 100644
> --- a/arch/powerpc/Makefile
> +++ b/arch/powerpc/Makefile
> @@ -12,12 +12,12 @@
>   # Rewritten by Cort Dougan and Paul Mackerras
>   #
>   
> -HAS_BIARCH	:= $(call cc-option-yn, -m32)
> +HAS_BIARCH	:= $(call cc-option,-m32)
>   
>   # Set default 32 bits cross compilers for vdso and boot wrapper
>   CROSS32_COMPILE ?=
>   
> -ifeq ($(HAS_BIARCH),y)
> +ifeq ($(HAS_BIARCH),-m32)
>   ifeq ($(CROSS32_COMPILE),)
>   ifdef CONFIG_PPC32
>   # These options will be overridden by any -mcpu option that the CPU
> @@ -107,7 +107,7 @@ cflags-$(CONFIG_CPU_LITTLE_ENDIAN)	+= -mlittle-endian
>   aflags-$(CONFIG_CPU_BIG_ENDIAN)		+= $(call cc-option,-mbig-endian)
>   aflags-$(CONFIG_CPU_LITTLE_ENDIAN)	+= -mlittle-endian
>   
> -ifeq ($(HAS_BIARCH),y)
> +ifeq ($(HAS_BIARCH),-m32)
>   KBUILD_CFLAGS	+= -m$(BITS)
>   KBUILD_AFLAGS	+= -m$(BITS) -Wl,-a$(BITS)
>   KBUILD_LDFLAGS	+= -m elf$(BITS)$(LDEMULATION)
> @@ -125,7 +125,9 @@ LDFLAGS_vmlinux-$(CONFIG_RELOCATABLE) := -pie
>   LDFLAGS_vmlinux	:= $(LDFLAGS_vmlinux-y)
>   
>   ifdef CONFIG_PPC64
> -ifeq ($(call cc-option-yn,-mcmodel=medium),y)
> +ifeq ($(call cc-option,-mcmodel=medium),)
> +	export NO_MINIMAL_TOC := -mno-minimal-toc
> +else
>   	# -mcmodel=medium breaks modules because it uses 32bit offsets from
>   	# the TOC pointer to create pointers where possible. Pointers into the
>   	# percpu data area are created by this method.
> @@ -135,8 +137,6 @@ ifeq ($(call cc-option-yn,-mcmodel=medium),y)
>   	# kernel percpu data space (starting with 0xc...). We need a full
>   	# 64bit relocation for this to work, hence -mcmodel=large.
>   	KBUILD_CFLAGS_MODULE += -mcmodel=large
> -else
> -	export NO_MINIMAL_TOC := -mno-minimal-toc
>   endif
>   endif
>   
> diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
> index 10c0fb306f15..33e1de5d1c95 100644
> --- a/arch/powerpc/boot/Makefile
> +++ b/arch/powerpc/boot/Makefile
> @@ -66,10 +66,7 @@ ifdef CONFIG_DEBUG_INFO
>   BOOTCFLAGS	+= -g
>   endif
>   
> -ifeq ($(call cc-option-yn, -fstack-protector),y)
> -BOOTCFLAGS	+= -fno-stack-protector
> -endif
> -
> +BOOTCFLAGS	+= $(call cc-option,-fstack-protector)

This was previously disabling the stack protector but now it is enabling 
it. Just remove the ifeq conditional altogether as the kernel assumes 
-fno-stack-protector is always supported after commit 893ab00439a4 
("kbuild: remove cc-option test of -fno-stack-protector").

>   BOOTCFLAGS	+= -I$(objtree)/$(obj) -I$(srctree)/$(obj)
>   
>   DTC_FLAGS	?= -p 1024
> 

Re: [PATCH 3/7] powerpc: replace cc-option-yn uses with cc-option

[Michael Ellerman]

Nick Desaulniers <ndesaulniers@google.com> writes:
> cc-option-yn can be replaced with cc-option. ie.
> Checking for support:
> ifeq ($(call cc-option-yn,$(FLAG)),y)
> becomes:
> ifneq ($(call cc-option,$(FLAG)),)
>
> Checking for lack of support:
> ifeq ($(call cc-option-yn,$(FLAG)),n)
> becomes:
> ifeq ($(call cc-option,$(FLAG)),)
>
> This allows us to pursue removing cc-option-yn.
>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: linuxppc-dev@lists.ozlabs.org
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> ---
>  arch/powerpc/Makefile      | 12 ++++++------
>  arch/powerpc/boot/Makefile |  5 +----
>  2 files changed, 7 insertions(+), 10 deletions(-)
>
> diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
> index 9aaf1abbc641..85e224536cf7 100644
> --- a/arch/powerpc/Makefile
> +++ b/arch/powerpc/Makefile
> @@ -12,12 +12,12 @@
>  # Rewritten by Cort Dougan and Paul Mackerras
>  #
>  
> -HAS_BIARCH	:= $(call cc-option-yn, -m32)
> +HAS_BIARCH	:= $(call cc-option,-m32)
>  
>  # Set default 32 bits cross compilers for vdso and boot wrapper
>  CROSS32_COMPILE ?=
>  
> -ifeq ($(HAS_BIARCH),y)
> +ifeq ($(HAS_BIARCH),-m32)

I don't love that we have to repeat "-m32" in each check.

I'm pretty sure you can use ifdef here, because HAS_BIARCH is a simple
variable (assigned with ":=").

ie, this can be:

  ifdef HAS_BIARCH


And that avoids having to spell out "-m32" everywhere.

cheers

Re: [PATCH 3/7] powerpc: replace cc-option-yn uses with cc-option

[Michael Ellerman]

Nick Desaulniers <ndesaulniers@google.com> writes:
> cc-option-yn can be replaced with cc-option. ie.
> Checking for support:
> ifeq ($(call cc-option-yn,$(FLAG)),y)
> becomes:
> ifneq ($(call cc-option,$(FLAG)),)
>
> Checking for lack of support:
> ifeq ($(call cc-option-yn,$(FLAG)),n)
> becomes:
> ifeq ($(call cc-option,$(FLAG)),)
>
> This allows us to pursue removing cc-option-yn.
>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: linuxppc-dev@lists.ozlabs.org
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> ---
>  arch/powerpc/Makefile      | 12 ++++++------
>  arch/powerpc/boot/Makefile |  5 +----
>  2 files changed, 7 insertions(+), 10 deletions(-)
>
> diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
> index 9aaf1abbc641..85e224536cf7 100644
> --- a/arch/powerpc/Makefile
> +++ b/arch/powerpc/Makefile
> @@ -12,12 +12,12 @@
>  # Rewritten by Cort Dougan and Paul Mackerras
>  #
>  
> -HAS_BIARCH	:= $(call cc-option-yn, -m32)
> +HAS_BIARCH	:= $(call cc-option,-m32)
>  
>  # Set default 32 bits cross compilers for vdso and boot wrapper
>  CROSS32_COMPILE ?=
>  
> -ifeq ($(HAS_BIARCH),y)
> +ifeq ($(HAS_BIARCH),-m32)

I don't love that we have to repeat "-m32" in each check.

I'm pretty sure you can use ifdef here, because HAS_BIARCH is a simple
variable (assigned with ":=").

ie, this can be:

  ifdef HAS_BIARCH


And that avoids having to spell out "-m32" everywhere.

cheers

Re: [PATCH 3/7] powerpc: replace cc-option-yn uses with cc-option

[Masahiro Yamada]

On Tue, Aug 17, 2021 at 11:31 AM Michael Ellerman <mpe@ellerman.id.au> wrote:
>
> Nick Desaulniers <ndesaulniers@google.com> writes:
> > cc-option-yn can be replaced with cc-option. ie.
> > Checking for support:
> > ifeq ($(call cc-option-yn,$(FLAG)),y)
> > becomes:
> > ifneq ($(call cc-option,$(FLAG)),)
> >
> > Checking for lack of support:
> > ifeq ($(call cc-option-yn,$(FLAG)),n)
> > becomes:
> > ifeq ($(call cc-option,$(FLAG)),)
> >
> > This allows us to pursue removing cc-option-yn.
> >
> > Cc: Michael Ellerman <mpe@ellerman.id.au>
> > Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> > Cc: Paul Mackerras <paulus@samba.org>
> > Cc: linuxppc-dev@lists.ozlabs.org
> > Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> > ---
> >  arch/powerpc/Makefile      | 12 ++++++------
> >  arch/powerpc/boot/Makefile |  5 +----
> >  2 files changed, 7 insertions(+), 10 deletions(-)
> >
> > diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
> > index 9aaf1abbc641..85e224536cf7 100644
> > --- a/arch/powerpc/Makefile
> > +++ b/arch/powerpc/Makefile
> > @@ -12,12 +12,12 @@
> >  # Rewritten by Cort Dougan and Paul Mackerras
> >  #
> >
> > -HAS_BIARCH   := $(call cc-option-yn, -m32)
> > +HAS_BIARCH   := $(call cc-option,-m32)
> >
> >  # Set default 32 bits cross compilers for vdso and boot wrapper
> >  CROSS32_COMPILE ?=
> >
> > -ifeq ($(HAS_BIARCH),y)
> > +ifeq ($(HAS_BIARCH),-m32)
>
> I don't love that we have to repeat "-m32" in each check.
>
> I'm pretty sure you can use ifdef here, because HAS_BIARCH is a simple
> variable (assigned with ":=").
>
> ie, this can be:
>
>   ifdef HAS_BIARCH
>
>
> And that avoids having to spell out "-m32" everywhere.
>
> cheers


Yes.

Comments from Nathan and Michael
both sound good.

-- 
Best Regards
Masahiro Yamada

Re: [PATCH 3/7] powerpc: replace cc-option-yn uses with cc-option

[Masahiro Yamada]

On Tue, Aug 17, 2021 at 11:31 AM Michael Ellerman <mpe@ellerman.id.au> wrote:
>
> Nick Desaulniers <ndesaulniers@google.com> writes:
> > cc-option-yn can be replaced with cc-option. ie.
> > Checking for support:
> > ifeq ($(call cc-option-yn,$(FLAG)),y)
> > becomes:
> > ifneq ($(call cc-option,$(FLAG)),)
> >
> > Checking for lack of support:
> > ifeq ($(call cc-option-yn,$(FLAG)),n)
> > becomes:
> > ifeq ($(call cc-option,$(FLAG)),)
> >
> > This allows us to pursue removing cc-option-yn.
> >
> > Cc: Michael Ellerman <mpe@ellerman.id.au>
> > Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> > Cc: Paul Mackerras <paulus@samba.org>
> > Cc: linuxppc-dev@lists.ozlabs.org
> > Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> > ---
> >  arch/powerpc/Makefile      | 12 ++++++------
> >  arch/powerpc/boot/Makefile |  5 +----
> >  2 files changed, 7 insertions(+), 10 deletions(-)
> >
> > diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
> > index 9aaf1abbc641..85e224536cf7 100644
> > --- a/arch/powerpc/Makefile
> > +++ b/arch/powerpc/Makefile
> > @@ -12,12 +12,12 @@
> >  # Rewritten by Cort Dougan and Paul Mackerras
> >  #
> >
> > -HAS_BIARCH   := $(call cc-option-yn, -m32)
> > +HAS_BIARCH   := $(call cc-option,-m32)
> >
> >  # Set default 32 bits cross compilers for vdso and boot wrapper
> >  CROSS32_COMPILE ?=
> >
> > -ifeq ($(HAS_BIARCH),y)
> > +ifeq ($(HAS_BIARCH),-m32)
>
> I don't love that we have to repeat "-m32" in each check.
>
> I'm pretty sure you can use ifdef here, because HAS_BIARCH is a simple
> variable (assigned with ":=").
>
> ie, this can be:
>
>   ifdef HAS_BIARCH
>
>
> And that avoids having to spell out "-m32" everywhere.
>
> cheers


Yes.

Comments from Nathan and Michael
both sound good.

-- 
Best Regards
Masahiro Yamada

[PATCH 4/7] arc: replace cc-option-yn uses with cc-option

[Nick Desaulniers]

cc-option-yn can be replaced with cc-option. ie.
Checking for support:
ifeq ($(call cc-option-yn,$(FLAG)),y)
becomes:
ifneq ($(call cc-option,$(FLAG)),)

Checking for lack of support:
ifeq ($(call cc-option-yn,$(FLAG)),n)
becomes:
ifeq ($(call cc-option,$(FLAG)),)

This allows us to pursue removing cc-option-yn.

Cc: Vineet Gupta <vgupta@kernel.org>
Cc: linux-snps-arc@lists.infradead.org
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
 arch/arc/Makefile | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/arc/Makefile b/arch/arc/Makefile
index c0d87ac2e221..8782a03f24a8 100644
--- a/arch/arc/Makefile
+++ b/arch/arc/Makefile
@@ -18,8 +18,7 @@ ifeq ($(CONFIG_ARC_TUNE_MCPU),"")
 cflags-y				+= $(tune-mcpu-def-y)
 else
 tune-mcpu				:= $(shell echo $(CONFIG_ARC_TUNE_MCPU))
-tune-mcpu-ok 				:= $(call cc-option-yn, $(tune-mcpu))
-ifeq ($(tune-mcpu-ok),y)
+ifneq ($(call cc-option,$(tune-mcpu)),)
 cflags-y				+= $(tune-mcpu)
 else
 # The flag provided by 'CONFIG_ARC_TUNE_MCPU' option isn't known by this compiler
-- 
2.33.0.rc1.237.g0d66db33f3-goog

[PATCH 4/7] arc: replace cc-option-yn uses with cc-option

[Nick Desaulniers]

cc-option-yn can be replaced with cc-option. ie.
Checking for support:
ifeq ($(call cc-option-yn,$(FLAG)),y)
becomes:
ifneq ($(call cc-option,$(FLAG)),)

Checking for lack of support:
ifeq ($(call cc-option-yn,$(FLAG)),n)
becomes:
ifeq ($(call cc-option,$(FLAG)),)

This allows us to pursue removing cc-option-yn.

Cc: Vineet Gupta <vgupta@kernel.org>
Cc: linux-snps-arc@lists.infradead.org
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
 arch/arc/Makefile | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/arc/Makefile b/arch/arc/Makefile
index c0d87ac2e221..8782a03f24a8 100644
--- a/arch/arc/Makefile
+++ b/arch/arc/Makefile
@@ -18,8 +18,7 @@ ifeq ($(CONFIG_ARC_TUNE_MCPU),"")
 cflags-y				+= $(tune-mcpu-def-y)
 else
 tune-mcpu				:= $(shell echo $(CONFIG_ARC_TUNE_MCPU))
-tune-mcpu-ok 				:= $(call cc-option-yn, $(tune-mcpu))
-ifeq ($(tune-mcpu-ok),y)
+ifneq ($(call cc-option,$(tune-mcpu)),)
 cflags-y				+= $(tune-mcpu)
 else
 # The flag provided by 'CONFIG_ARC_TUNE_MCPU' option isn't known by this compiler
-- 
2.33.0.rc1.237.g0d66db33f3-goog


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Re: [PATCH 4/7] arc: replace cc-option-yn uses with cc-option

[Nathan Chancellor]

On 8/16/2021 5:21 PM, 'Nick Desaulniers' via Clang Built Linux wrote:
> cc-option-yn can be replaced with cc-option. ie.
> Checking for support:
> ifeq ($(call cc-option-yn,$(FLAG)),y)
> becomes:
> ifneq ($(call cc-option,$(FLAG)),)
> 
> Checking for lack of support:
> ifeq ($(call cc-option-yn,$(FLAG)),n)
> becomes:
> ifeq ($(call cc-option,$(FLAG)),)
> 
> This allows us to pursue removing cc-option-yn.
> 
> Cc: Vineet Gupta <vgupta@kernel.org>
> Cc: linux-snps-arc@lists.infradead.org
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> ---
>   arch/arc/Makefile | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/arch/arc/Makefile b/arch/arc/Makefile
> index c0d87ac2e221..8782a03f24a8 100644
> --- a/arch/arc/Makefile
> +++ b/arch/arc/Makefile
> @@ -18,8 +18,7 @@ ifeq ($(CONFIG_ARC_TUNE_MCPU),"")
>   cflags-y				+= $(tune-mcpu-def-y)
>   else
>   tune-mcpu				:= $(shell echo $(CONFIG_ARC_TUNE_MCPU))
> -tune-mcpu-ok 				:= $(call cc-option-yn, $(tune-mcpu))
> -ifeq ($(tune-mcpu-ok),y)
> +ifneq ($(call cc-option,$(tune-mcpu)),)
>   cflags-y				+= $(tune-mcpu)

Any reason not to just turn this into

cflags-y += $(call cc-option,$(tune-mcpu))

?

If $(tune-mcpu) is empty or invalid, nothing will be added to cflags-y.

>   else
>   # The flag provided by 'CONFIG_ARC_TUNE_MCPU' option isn't known by this compiler
> 

Re: [PATCH 4/7] arc: replace cc-option-yn uses with cc-option

[Nathan Chancellor]

On 8/16/2021 5:21 PM, 'Nick Desaulniers' via Clang Built Linux wrote:
> cc-option-yn can be replaced with cc-option. ie.
> Checking for support:
> ifeq ($(call cc-option-yn,$(FLAG)),y)
> becomes:
> ifneq ($(call cc-option,$(FLAG)),)
> 
> Checking for lack of support:
> ifeq ($(call cc-option-yn,$(FLAG)),n)
> becomes:
> ifeq ($(call cc-option,$(FLAG)),)
> 
> This allows us to pursue removing cc-option-yn.
> 
> Cc: Vineet Gupta <vgupta@kernel.org>
> Cc: linux-snps-arc@lists.infradead.org
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> ---
>   arch/arc/Makefile | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/arch/arc/Makefile b/arch/arc/Makefile
> index c0d87ac2e221..8782a03f24a8 100644
> --- a/arch/arc/Makefile
> +++ b/arch/arc/Makefile
> @@ -18,8 +18,7 @@ ifeq ($(CONFIG_ARC_TUNE_MCPU),"")
>   cflags-y				+= $(tune-mcpu-def-y)
>   else
>   tune-mcpu				:= $(shell echo $(CONFIG_ARC_TUNE_MCPU))
> -tune-mcpu-ok 				:= $(call cc-option-yn, $(tune-mcpu))
> -ifeq ($(tune-mcpu-ok),y)
> +ifneq ($(call cc-option,$(tune-mcpu)),)
>   cflags-y				+= $(tune-mcpu)

Any reason not to just turn this into

cflags-y += $(call cc-option,$(tune-mcpu))

?

If $(tune-mcpu) is empty or invalid, nothing will be added to cflags-y.

>   else
>   # The flag provided by 'CONFIG_ARC_TUNE_MCPU' option isn't known by this compiler
> 

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Re: [PATCH 4/7] arc: replace cc-option-yn uses with cc-option

[Nick Desaulniers]

On Mon, Aug 16, 2021 at 7:05 PM Nathan Chancellor <nathan@kernel.org> wrote:
>
> On 8/16/2021 5:21 PM, 'Nick Desaulniers' via Clang Built Linux wrote:
> > cc-option-yn can be replaced with cc-option. ie.
> > Checking for support:
> > ifeq ($(call cc-option-yn,$(FLAG)),y)
> > becomes:
> > ifneq ($(call cc-option,$(FLAG)),)
> >
> > Checking for lack of support:
> > ifeq ($(call cc-option-yn,$(FLAG)),n)
> > becomes:
> > ifeq ($(call cc-option,$(FLAG)),)
> >
> > This allows us to pursue removing cc-option-yn.
> >
> > Cc: Vineet Gupta <vgupta@kernel.org>
> > Cc: linux-snps-arc@lists.infradead.org
> > Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> > ---
> >   arch/arc/Makefile | 3 +--
> >   1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/arch/arc/Makefile b/arch/arc/Makefile
> > index c0d87ac2e221..8782a03f24a8 100644
> > --- a/arch/arc/Makefile
> > +++ b/arch/arc/Makefile
> > @@ -18,8 +18,7 @@ ifeq ($(CONFIG_ARC_TUNE_MCPU),"")
> >   cflags-y                            += $(tune-mcpu-def-y)
> >   else
> >   tune-mcpu                           := $(shell echo $(CONFIG_ARC_TUNE_MCPU))
> > -tune-mcpu-ok                                 := $(call cc-option-yn, $(tune-mcpu))
> > -ifeq ($(tune-mcpu-ok),y)
> > +ifneq ($(call cc-option,$(tune-mcpu)),)
> >   cflags-y                            += $(tune-mcpu)
>
> Any reason not to just turn this into
>
> cflags-y += $(call cc-option,$(tune-mcpu))
>
> ?

Yes, you'll need to pull up the source; the diff doesn't provide
enough context. tune-mcpu is used in the body of the else branch
hinted at by the diff. PTAL

>
> If $(tune-mcpu) is empty or invalid, nothing will be added to cflags-y.
>
> >   else
> >   # The flag provided by 'CONFIG_ARC_TUNE_MCPU' option isn't known by this compiler
> >



-- 
Thanks,
~Nick Desaulniers

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Re: [PATCH 4/7] arc: replace cc-option-yn uses with cc-option

[Nick Desaulniers]

On Mon, Aug 16, 2021 at 7:05 PM Nathan Chancellor <nathan@kernel.org> wrote:
>
> On 8/16/2021 5:21 PM, 'Nick Desaulniers' via Clang Built Linux wrote:
> > cc-option-yn can be replaced with cc-option. ie.
> > Checking for support:
> > ifeq ($(call cc-option-yn,$(FLAG)),y)
> > becomes:
> > ifneq ($(call cc-option,$(FLAG)),)
> >
> > Checking for lack of support:
> > ifeq ($(call cc-option-yn,$(FLAG)),n)
> > becomes:
> > ifeq ($(call cc-option,$(FLAG)),)
> >
> > This allows us to pursue removing cc-option-yn.
> >
> > Cc: Vineet Gupta <vgupta@kernel.org>
> > Cc: linux-snps-arc@lists.infradead.org
> > Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> > ---
> >   arch/arc/Makefile | 3 +--
> >   1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/arch/arc/Makefile b/arch/arc/Makefile
> > index c0d87ac2e221..8782a03f24a8 100644
> > --- a/arch/arc/Makefile
> > +++ b/arch/arc/Makefile
> > @@ -18,8 +18,7 @@ ifeq ($(CONFIG_ARC_TUNE_MCPU),"")
> >   cflags-y                            += $(tune-mcpu-def-y)
> >   else
> >   tune-mcpu                           := $(shell echo $(CONFIG_ARC_TUNE_MCPU))
> > -tune-mcpu-ok                                 := $(call cc-option-yn, $(tune-mcpu))
> > -ifeq ($(tune-mcpu-ok),y)
> > +ifneq ($(call cc-option,$(tune-mcpu)),)
> >   cflags-y                            += $(tune-mcpu)
>
> Any reason not to just turn this into
>
> cflags-y += $(call cc-option,$(tune-mcpu))
>
> ?

Yes, you'll need to pull up the source; the diff doesn't provide
enough context. tune-mcpu is used in the body of the else branch
hinted at by the diff. PTAL

>
> If $(tune-mcpu) is empty or invalid, nothing will be added to cflags-y.
>
> >   else
> >   # The flag provided by 'CONFIG_ARC_TUNE_MCPU' option isn't known by this compiler
> >



-- 
Thanks,
~Nick Desaulniers

Re: [PATCH 4/7] arc: replace cc-option-yn uses with cc-option

[Nathan Chancellor]

On 8/17/2021 11:07 AM, 'Nick Desaulniers' via Clang Built Linux wrote:
> On Mon, Aug 16, 2021 at 7:05 PM Nathan Chancellor <nathan@kernel.org> wrote:
>>
>> On 8/16/2021 5:21 PM, 'Nick Desaulniers' via Clang Built Linux wrote:
>>> cc-option-yn can be replaced with cc-option. ie.
>>> Checking for support:
>>> ifeq ($(call cc-option-yn,$(FLAG)),y)
>>> becomes:
>>> ifneq ($(call cc-option,$(FLAG)),)
>>>
>>> Checking for lack of support:
>>> ifeq ($(call cc-option-yn,$(FLAG)),n)
>>> becomes:
>>> ifeq ($(call cc-option,$(FLAG)),)
>>>
>>> This allows us to pursue removing cc-option-yn.
>>>
>>> Cc: Vineet Gupta <vgupta@kernel.org>
>>> Cc: linux-snps-arc@lists.infradead.org
>>> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
>>> ---
>>>    arch/arc/Makefile | 3 +--
>>>    1 file changed, 1 insertion(+), 2 deletions(-)
>>>
>>> diff --git a/arch/arc/Makefile b/arch/arc/Makefile
>>> index c0d87ac2e221..8782a03f24a8 100644
>>> --- a/arch/arc/Makefile
>>> +++ b/arch/arc/Makefile
>>> @@ -18,8 +18,7 @@ ifeq ($(CONFIG_ARC_TUNE_MCPU),"")
>>>    cflags-y                            += $(tune-mcpu-def-y)
>>>    else
>>>    tune-mcpu                           := $(shell echo $(CONFIG_ARC_TUNE_MCPU))
>>> -tune-mcpu-ok                                 := $(call cc-option-yn, $(tune-mcpu))
>>> -ifeq ($(tune-mcpu-ok),y)
>>> +ifneq ($(call cc-option,$(tune-mcpu)),)
>>>    cflags-y                            += $(tune-mcpu)
>>
>> Any reason not to just turn this into
>>
>> cflags-y += $(call cc-option,$(tune-mcpu))
>>
>> ?
> 
> Yes, you'll need to pull up the source; the diff doesn't provide
> enough context. tune-mcpu is used in the body of the else branch
> hinted at by the diff. PTAL

Ah, fair enough. The warning is a little unconventional but oh well :)

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

>>
>> If $(tune-mcpu) is empty or invalid, nothing will be added to cflags-y.
>>
>>>    else
>>>    # The flag provided by 'CONFIG_ARC_TUNE_MCPU' option isn't known by this compiler
>>>
> 
> 
> 

Re: [PATCH 4/7] arc: replace cc-option-yn uses with cc-option

[Nathan Chancellor]

On 8/17/2021 11:07 AM, 'Nick Desaulniers' via Clang Built Linux wrote:
> On Mon, Aug 16, 2021 at 7:05 PM Nathan Chancellor <nathan@kernel.org> wrote:
>>
>> On 8/16/2021 5:21 PM, 'Nick Desaulniers' via Clang Built Linux wrote:
>>> cc-option-yn can be replaced with cc-option. ie.
>>> Checking for support:
>>> ifeq ($(call cc-option-yn,$(FLAG)),y)
>>> becomes:
>>> ifneq ($(call cc-option,$(FLAG)),)
>>>
>>> Checking for lack of support:
>>> ifeq ($(call cc-option-yn,$(FLAG)),n)
>>> becomes:
>>> ifeq ($(call cc-option,$(FLAG)),)
>>>
>>> This allows us to pursue removing cc-option-yn.
>>>
>>> Cc: Vineet Gupta <vgupta@kernel.org>
>>> Cc: linux-snps-arc@lists.infradead.org
>>> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
>>> ---
>>>    arch/arc/Makefile | 3 +--
>>>    1 file changed, 1 insertion(+), 2 deletions(-)
>>>
>>> diff --git a/arch/arc/Makefile b/arch/arc/Makefile
>>> index c0d87ac2e221..8782a03f24a8 100644
>>> --- a/arch/arc/Makefile
>>> +++ b/arch/arc/Makefile
>>> @@ -18,8 +18,7 @@ ifeq ($(CONFIG_ARC_TUNE_MCPU),"")
>>>    cflags-y                            += $(tune-mcpu-def-y)
>>>    else
>>>    tune-mcpu                           := $(shell echo $(CONFIG_ARC_TUNE_MCPU))
>>> -tune-mcpu-ok                                 := $(call cc-option-yn, $(tune-mcpu))
>>> -ifeq ($(tune-mcpu-ok),y)
>>> +ifneq ($(call cc-option,$(tune-mcpu)),)
>>>    cflags-y                            += $(tune-mcpu)
>>
>> Any reason not to just turn this into
>>
>> cflags-y += $(call cc-option,$(tune-mcpu))
>>
>> ?
> 
> Yes, you'll need to pull up the source; the diff doesn't provide
> enough context. tune-mcpu is used in the body of the else branch
> hinted at by the diff. PTAL

Ah, fair enough. The warning is a little unconventional but oh well :)

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

>>
>> If $(tune-mcpu) is empty or invalid, nothing will be added to cflags-y.
>>
>>>    else
>>>    # The flag provided by 'CONFIG_ARC_TUNE_MCPU' option isn't known by this compiler
>>>
> 
> 
> 

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Re: [PATCH 4/7] arc: replace cc-option-yn uses with cc-option

[Masahiro Yamada]

On Wed, Aug 18, 2021 at 10:40 AM Nathan Chancellor <nathan@kernel.org> wrote:
>
>
>
> On 8/17/2021 11:07 AM, 'Nick Desaulniers' via Clang Built Linux wrote:
> > On Mon, Aug 16, 2021 at 7:05 PM Nathan Chancellor <nathan@kernel.org> wrote:
> >>
> >> On 8/16/2021 5:21 PM, 'Nick Desaulniers' via Clang Built Linux wrote:
> >>> cc-option-yn can be replaced with cc-option. ie.
> >>> Checking for support:
> >>> ifeq ($(call cc-option-yn,$(FLAG)),y)
> >>> becomes:
> >>> ifneq ($(call cc-option,$(FLAG)),)
> >>>
> >>> Checking for lack of support:
> >>> ifeq ($(call cc-option-yn,$(FLAG)),n)
> >>> becomes:
> >>> ifeq ($(call cc-option,$(FLAG)),)
> >>>
> >>> This allows us to pursue removing cc-option-yn.
> >>>
> >>> Cc: Vineet Gupta <vgupta@kernel.org>
> >>> Cc: linux-snps-arc@lists.infradead.org
> >>> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> >>> ---
> >>>    arch/arc/Makefile | 3 +--
> >>>    1 file changed, 1 insertion(+), 2 deletions(-)
> >>>
> >>> diff --git a/arch/arc/Makefile b/arch/arc/Makefile
> >>> index c0d87ac2e221..8782a03f24a8 100644
> >>> --- a/arch/arc/Makefile
> >>> +++ b/arch/arc/Makefile
> >>> @@ -18,8 +18,7 @@ ifeq ($(CONFIG_ARC_TUNE_MCPU),"")
> >>>    cflags-y                            += $(tune-mcpu-def-y)
> >>>    else
> >>>    tune-mcpu                           := $(shell echo $(CONFIG_ARC_TUNE_MCPU))
> >>> -tune-mcpu-ok                                 := $(call cc-option-yn, $(tune-mcpu))
> >>> -ifeq ($(tune-mcpu-ok),y)
> >>> +ifneq ($(call cc-option,$(tune-mcpu)),)
> >>>    cflags-y                            += $(tune-mcpu)
> >>
> >> Any reason not to just turn this into
> >>
> >> cflags-y += $(call cc-option,$(tune-mcpu))
> >>
> >> ?
> >
> > Yes, you'll need to pull up the source; the diff doesn't provide
> > enough context. tune-mcpu is used in the body of the else branch
> > hinted at by the diff. PTAL
>
> Ah, fair enough. The warning is a little unconventional but oh well :)
>
> Reviewed-by: Nathan Chancellor <nathan@kernel.org>
>
> >>
> >> If $(tune-mcpu) is empty or invalid, nothing will be added to cflags-y.
> >>
> >>>    else
> >>>    # The flag provided by 'CONFIG_ARC_TUNE_MCPU' option isn't known by this compiler
> >>>
> >
> >
> >

Applied to linux-kbuild.


-- 
Best Regards
Masahiro Yamada

Re: [PATCH 4/7] arc: replace cc-option-yn uses with cc-option

[Masahiro Yamada]

On Wed, Aug 18, 2021 at 10:40 AM Nathan Chancellor <nathan@kernel.org> wrote:
>
>
>
> On 8/17/2021 11:07 AM, 'Nick Desaulniers' via Clang Built Linux wrote:
> > On Mon, Aug 16, 2021 at 7:05 PM Nathan Chancellor <nathan@kernel.org> wrote:
> >>
> >> On 8/16/2021 5:21 PM, 'Nick Desaulniers' via Clang Built Linux wrote:
> >>> cc-option-yn can be replaced with cc-option. ie.
> >>> Checking for support:
> >>> ifeq ($(call cc-option-yn,$(FLAG)),y)
> >>> becomes:
> >>> ifneq ($(call cc-option,$(FLAG)),)
> >>>
> >>> Checking for lack of support:
> >>> ifeq ($(call cc-option-yn,$(FLAG)),n)
> >>> becomes:
> >>> ifeq ($(call cc-option,$(FLAG)),)
> >>>
> >>> This allows us to pursue removing cc-option-yn.
> >>>
> >>> Cc: Vineet Gupta <vgupta@kernel.org>
> >>> Cc: linux-snps-arc@lists.infradead.org
> >>> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> >>> ---
> >>>    arch/arc/Makefile | 3 +--
> >>>    1 file changed, 1 insertion(+), 2 deletions(-)
> >>>
> >>> diff --git a/arch/arc/Makefile b/arch/arc/Makefile
> >>> index c0d87ac2e221..8782a03f24a8 100644
> >>> --- a/arch/arc/Makefile
> >>> +++ b/arch/arc/Makefile
> >>> @@ -18,8 +18,7 @@ ifeq ($(CONFIG_ARC_TUNE_MCPU),"")
> >>>    cflags-y                            += $(tune-mcpu-def-y)
> >>>    else
> >>>    tune-mcpu                           := $(shell echo $(CONFIG_ARC_TUNE_MCPU))
> >>> -tune-mcpu-ok                                 := $(call cc-option-yn, $(tune-mcpu))
> >>> -ifeq ($(tune-mcpu-ok),y)
> >>> +ifneq ($(call cc-option,$(tune-mcpu)),)
> >>>    cflags-y                            += $(tune-mcpu)
> >>
> >> Any reason not to just turn this into
> >>
> >> cflags-y += $(call cc-option,$(tune-mcpu))
> >>
> >> ?
> >
> > Yes, you'll need to pull up the source; the diff doesn't provide
> > enough context. tune-mcpu is used in the body of the else branch
> > hinted at by the diff. PTAL
>
> Ah, fair enough. The warning is a little unconventional but oh well :)
>
> Reviewed-by: Nathan Chancellor <nathan@kernel.org>
>
> >>
> >> If $(tune-mcpu) is empty or invalid, nothing will be added to cflags-y.
> >>
> >>>    else
> >>>    # The flag provided by 'CONFIG_ARC_TUNE_MCPU' option isn't known by this compiler
> >>>
> >
> >
> >

Applied to linux-kbuild.


-- 
Best Regards
Masahiro Yamada

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[PATCH 5/7] x86: remove cc-option-yn test for -mtune=

[Nick Desaulniers]

As noted in the comment, -mtune= has been supported since GCC 3.4. The
minimum required version of GCC to build the kernel (as specified in
Documentation/process/changes.rst) is GCC 4.9.

tune is not immediately expanded. Instead it defines a macro that will
test via cc-option later values for -mtune=. But we can skip the test
whether to use -mtune= vs. -mcpu=.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: x86@kernel.org
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
 arch/x86/Makefile_32.cpu | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/arch/x86/Makefile_32.cpu b/arch/x86/Makefile_32.cpu
index cd3056759880..e7355f8b51c2 100644
--- a/arch/x86/Makefile_32.cpu
+++ b/arch/x86/Makefile_32.cpu
@@ -2,13 +2,7 @@
 # CPU tuning section - shared with UML.
 # Must change only cflags-y (or [yn]), not CFLAGS! That makes a difference for UML.
 
-#-mtune exists since gcc 3.4
-HAS_MTUNE	:= $(call cc-option-yn, -mtune=i386)
-ifeq ($(HAS_MTUNE),y)
 tune		= $(call cc-option,-mtune=$(1),$(2))
-else
-tune		= $(call cc-option,-mcpu=$(1),$(2))
-endif
 
 cflags-$(CONFIG_M486SX)		+= -march=i486
 cflags-$(CONFIG_M486)		+= -march=i486
-- 
2.33.0.rc1.237.g0d66db33f3-goog

Re: [PATCH 5/7] x86: remove cc-option-yn test for -mtune=

[Nathan Chancellor]

On 8/16/2021 5:21 PM, 'Nick Desaulniers' via Clang Built Linux wrote:
> As noted in the comment, -mtune= has been supported since GCC 3.4. The
> minimum required version of GCC to build the kernel (as specified in
> Documentation/process/changes.rst) is GCC 4.9.
> 
> tune is not immediately expanded. Instead it defines a macro that will
> test via cc-option later values for -mtune=. But we can skip the test
> whether to use -mtune= vs. -mcpu=.
> 
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Borislav Petkov <bp@alien8.de>
> Cc: H. Peter Anvin <hpa@zytor.com>
> Cc: x86@kernel.org
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>

Yay for removing stale checks!

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

> ---
>   arch/x86/Makefile_32.cpu | 6 ------
>   1 file changed, 6 deletions(-)
> 
> diff --git a/arch/x86/Makefile_32.cpu b/arch/x86/Makefile_32.cpu
> index cd3056759880..e7355f8b51c2 100644
> --- a/arch/x86/Makefile_32.cpu
> +++ b/arch/x86/Makefile_32.cpu
> @@ -2,13 +2,7 @@
>   # CPU tuning section - shared with UML.
>   # Must change only cflags-y (or [yn]), not CFLAGS! That makes a difference for UML.
>   
> -#-mtune exists since gcc 3.4
> -HAS_MTUNE	:= $(call cc-option-yn, -mtune=i386)
> -ifeq ($(HAS_MTUNE),y)
>   tune		= $(call cc-option,-mtune=$(1),$(2))
> -else
> -tune		= $(call cc-option,-mcpu=$(1),$(2))
> -endif
>   
>   cflags-$(CONFIG_M486SX)		+= -march=i486
>   cflags-$(CONFIG_M486)		+= -march=i486
> 

Re: [PATCH 5/7] x86: remove cc-option-yn test for -mtune=

[Masahiro Yamada]

On Tue, Aug 17, 2021 at 9:21 AM Nick Desaulniers
<ndesaulniers@google.com> wrote:
>
> As noted in the comment, -mtune= has been supported since GCC 3.4. The
> minimum required version of GCC to build the kernel (as specified in
> Documentation/process/changes.rst) is GCC 4.9.
>
> tune is not immediately expanded. Instead it defines a macro that will
> test via cc-option later values for -mtune=. But we can skip the test
> whether to use -mtune= vs. -mcpu=.
>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Borislav Petkov <bp@alien8.de>
> Cc: H. Peter Anvin <hpa@zytor.com>
> Cc: x86@kernel.org
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> ---
>  arch/x86/Makefile_32.cpu | 6 ------
>  1 file changed, 6 deletions(-)
>
> diff --git a/arch/x86/Makefile_32.cpu b/arch/x86/Makefile_32.cpu
> index cd3056759880..e7355f8b51c2 100644
> --- a/arch/x86/Makefile_32.cpu
> +++ b/arch/x86/Makefile_32.cpu
> @@ -2,13 +2,7 @@
>  # CPU tuning section - shared with UML.
>  # Must change only cflags-y (or [yn]), not CFLAGS! That makes a difference for UML.
>
> -#-mtune exists since gcc 3.4
> -HAS_MTUNE      := $(call cc-option-yn, -mtune=i386)
> -ifeq ($(HAS_MTUNE),y)
>  tune           = $(call cc-option,-mtune=$(1),$(2))
> -else
> -tune           = $(call cc-option,-mcpu=$(1),$(2))
> -endif
>
>  cflags-$(CONFIG_M486SX)                += -march=i486
>  cflags-$(CONFIG_M486)          += -march=i486
> --
> 2.33.0.rc1.237.g0d66db33f3-goog
>

LGTM.

Perhaps, a follow-up patch can remove the tune macro too,
replacing  $(call tune,pentium2) with $(call cc-option,-mtune=pentium2)







--
Best Regards
Masahiro Yamada

Re: [PATCH 5/7] x86: remove cc-option-yn test for -mtune=

[Miguel Ojeda]

On Tue, Aug 17, 2021 at 2:21 AM 'Nick Desaulniers' via Clang Built
Linux <clang-built-linux@googlegroups.com> wrote:
>
> As noted in the comment, -mtune= has been supported since GCC 3.4. The
> minimum required version of GCC to build the kernel (as specified in
> Documentation/process/changes.rst) is GCC 4.9.

Yes, please!

Reviewed-by: Miguel Ojeda <ojeda@kernel.org>

Cheers,
Miguel

Re: [PATCH 5/7] x86: remove cc-option-yn test for -mtune=

[Masahiro Yamada]

On Fri, Aug 20, 2021 at 7:20 AM Miguel Ojeda
<miguel.ojeda.sandonis@gmail.com> wrote:
>
> On Tue, Aug 17, 2021 at 2:21 AM 'Nick Desaulniers' via Clang Built
> Linux <clang-built-linux@googlegroups.com> wrote:
> >
> > As noted in the comment, -mtune= has been supported since GCC 3.4. The
> > minimum required version of GCC to build the kernel (as specified in
> > Documentation/process/changes.rst) is GCC 4.9.
>
> Yes, please!
>
> Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
>
> Cheers,
> Miguel


Applied to linux-kbuild.



-- 
Best Regards
Masahiro Yamada

[PATCH 6/7] Makefile: replace cc-option-yn uses with cc-option

[Nick Desaulniers]

cc-option-yn can be replaced with cc-option. ie.
Checking for support:
ifeq ($(call cc-option-yn,$(FLAG)),y)
becomes:
ifneq ($(call cc-option,$(FLAG)),)

Checking for lack of support:
ifeq ($(call cc-option-yn,$(FLAG)),n)
becomes:
ifeq ($(call cc-option,$(FLAG)),)

This allows us to pursue removing cc-option-yn.

Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
 Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 72f9e2b0202c..f76be5f62d79 100644
--- a/Makefile
+++ b/Makefile
@@ -967,7 +967,7 @@ ifdef CONFIG_FUNCTION_TRACER
 ifdef CONFIG_FTRACE_MCOUNT_USE_CC
   CC_FLAGS_FTRACE	+= -mrecord-mcount
   ifdef CONFIG_HAVE_NOP_MCOUNT
-    ifeq ($(call cc-option-yn, -mnop-mcount),y)
+    ifneq ($(call cc-option, -mnop-mcount),)
       CC_FLAGS_FTRACE	+= -mnop-mcount
       CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
     endif
-- 
2.33.0.rc1.237.g0d66db33f3-goog

Re: [PATCH 6/7] Makefile: replace cc-option-yn uses with cc-option

[Nathan Chancellor]

On 8/16/2021 5:21 PM, 'Nick Desaulniers' via Clang Built Linux wrote:
> cc-option-yn can be replaced with cc-option. ie.
> Checking for support:
> ifeq ($(call cc-option-yn,$(FLAG)),y)
> becomes:
> ifneq ($(call cc-option,$(FLAG)),)
> 
> Checking for lack of support:
> ifeq ($(call cc-option-yn,$(FLAG)),n)
> becomes:
> ifeq ($(call cc-option,$(FLAG)),)
> 
> This allows us to pursue removing cc-option-yn.
> 
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

> ---
>   Makefile | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/Makefile b/Makefile
> index 72f9e2b0202c..f76be5f62d79 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -967,7 +967,7 @@ ifdef CONFIG_FUNCTION_TRACER
>   ifdef CONFIG_FTRACE_MCOUNT_USE_CC
>     CC_FLAGS_FTRACE	+= -mrecord-mcount
>     ifdef CONFIG_HAVE_NOP_MCOUNT
> -    ifeq ($(call cc-option-yn, -mnop-mcount),y)
> +    ifneq ($(call cc-option, -mnop-mcount),)
>         CC_FLAGS_FTRACE	+= -mnop-mcount
>         CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
>       endif
> 

Re: [PATCH 6/7] Makefile: replace cc-option-yn uses with cc-option

[Masahiro Yamada]

On Tue, Aug 17, 2021 at 9:21 AM 'Nick Desaulniers' via Clang Built
Linux <clang-built-linux@googlegroups.com> wrote:
>
> cc-option-yn can be replaced with cc-option. ie.
> Checking for support:
> ifeq ($(call cc-option-yn,$(FLAG)),y)
> becomes:
> ifneq ($(call cc-option,$(FLAG)),)
>
> Checking for lack of support:
> ifeq ($(call cc-option-yn,$(FLAG)),n)
> becomes:
> ifeq ($(call cc-option,$(FLAG)),)
>
> This allows us to pursue removing cc-option-yn.
>
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> ---
>  Makefile | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/Makefile b/Makefile
> index 72f9e2b0202c..f76be5f62d79 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -967,7 +967,7 @@ ifdef CONFIG_FUNCTION_TRACER
>  ifdef CONFIG_FTRACE_MCOUNT_USE_CC
>    CC_FLAGS_FTRACE      += -mrecord-mcount
>    ifdef CONFIG_HAVE_NOP_MCOUNT
> -    ifeq ($(call cc-option-yn, -mnop-mcount),y)
> +    ifneq ($(call cc-option, -mnop-mcount),)
>        CC_FLAGS_FTRACE  += -mnop-mcount
>        CC_FLAGS_USING   += -DCC_USING_NOP_MCOUNT
>      endif
> --
> 2.33.0.rc1.237.g0d66db33f3-goog
>
> --
> You received this message because you are subscribed to the Google Groups "Clang Built Linux" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to clang-built-linux+unsubscribe@googlegroups.com.
> To view this discussion on the web visit https://groups.google.com/d/msgid/clang-built-linux/20210817002109.2736222-7-ndesaulniers%40google.com.



I am fine with this change, but
is there any reason why you did not touch the following hunk?



ifdef CONFIG_HAVE_FENTRY
  # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
  ifeq ($(call cc-option-yn, -mfentry),y)
    CC_FLAGS_FTRACE     += -mfentry
    CC_FLAGS_USING      += -DCC_USING_FENTRY
  endif
endif









-- 
Best Regards
Masahiro Yamada

Re: [PATCH 6/7] Makefile: replace cc-option-yn uses with cc-option

[Masahiro Yamada]

On Wed, Aug 25, 2021 at 1:43 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> On Tue, Aug 17, 2021 at 9:21 AM 'Nick Desaulniers' via Clang Built
> Linux <clang-built-linux@googlegroups.com> wrote:
> >
> > cc-option-yn can be replaced with cc-option. ie.
> > Checking for support:
> > ifeq ($(call cc-option-yn,$(FLAG)),y)
> > becomes:
> > ifneq ($(call cc-option,$(FLAG)),)
> >
> > Checking for lack of support:
> > ifeq ($(call cc-option-yn,$(FLAG)),n)
> > becomes:
> > ifeq ($(call cc-option,$(FLAG)),)
> >
> > This allows us to pursue removing cc-option-yn.
> >
> > Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> > ---
> >  Makefile | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/Makefile b/Makefile
> > index 72f9e2b0202c..f76be5f62d79 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -967,7 +967,7 @@ ifdef CONFIG_FUNCTION_TRACER
> >  ifdef CONFIG_FTRACE_MCOUNT_USE_CC
> >    CC_FLAGS_FTRACE      += -mrecord-mcount
> >    ifdef CONFIG_HAVE_NOP_MCOUNT
> > -    ifeq ($(call cc-option-yn, -mnop-mcount),y)
> > +    ifneq ($(call cc-option, -mnop-mcount),)
> >        CC_FLAGS_FTRACE  += -mnop-mcount
> >        CC_FLAGS_USING   += -DCC_USING_NOP_MCOUNT
> >      endif
> > --
> > 2.33.0.rc1.237.g0d66db33f3-goog
> >
> > --
> > You received this message because you are subscribed to the Google Groups "Clang Built Linux" group.
> > To unsubscribe from this group and stop receiving emails from it, send an email to clang-built-linux+unsubscribe@googlegroups.com.
> > To view this discussion on the web visit https://groups.google.com/d/msgid/clang-built-linux/20210817002109.2736222-7-ndesaulniers%40google.com.
>
>
>
> I am fine with this change, but
> is there any reason why you did not touch the following hunk?
>
>
>
> ifdef CONFIG_HAVE_FENTRY
>   # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
>   ifeq ($(call cc-option-yn, -mfentry),y)
>     CC_FLAGS_FTRACE     += -mfentry
>     CC_FLAGS_USING      += -DCC_USING_FENTRY
>   endif
> endif
>


Ah, I just recalled that this hunk was restored
after a build error was reported:

https://lore.kernel.org/lkml/CAKwvOdkckey1=VUHApTcJYufyhdRJ=jb4qYs52f59g6ha7qphw@mail.gmail.com/



So, please send v2, changing -mfentry part in the same way.





-- 
Best Regards
Masahiro Yamada

[PATCH 7/7] kbuild: remove cc-option-yn, update Docs

[Nick Desaulniers]

cc-option-yn can be replaced with cc-option. ie.
Checking for support:
ifeq ($(call cc-option-yn,$(FLAG)),y)
becomes:
ifneq ($(call cc-option,$(FLAG)),)

Checking for lack of support:
ifeq ($(call cc-option-yn,$(FLAG)),n)
becomes:
ifeq ($(call cc-option,$(FLAG)),)

This allows us to remove cc-option-yn. Do so and update the docs with
examples.

Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
 Documentation/kbuild/makefiles.rst | 22 +++++++++-------------
 scripts/Makefile.compiler          |  5 -----
 2 files changed, 9 insertions(+), 18 deletions(-)

diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst
index db3af0b45baf..4538c36d8df0 100644
--- a/Documentation/kbuild/makefiles.rst
+++ b/Documentation/kbuild/makefiles.rst
@@ -650,24 +650,20 @@ more details, with real examples.
 	-march=pentium-mmx if supported by $(CC), otherwise -march=i586.
 	The second argument to cc-option is optional, and if omitted,
 	cflags-y will be assigned no value if first option is not supported.
-	Note: cc-option uses KBUILD_CFLAGS for $(CC) options
+	Note: cc-option uses KBUILD_CFLAGS for $(CC) options.
 
-   cc-option-yn
-	cc-option-yn is used to check if gcc supports a given option
-	and return 'y' if supported, otherwise 'n'.
+	cc-option can be combined with conditionals to perform actions based on tool
+	support.
 
 	Example::
 
-		#arch/ppc/Makefile
-		biarch := $(call cc-option-yn, -m32)
-		aflags-$(biarch) += -a32
-		cflags-$(biarch) += -m32
+		ifneq ($(call cc-option,$(FLAG)),)
+		# $(FLAG) is supported
 
-	In the above example, $(biarch) is set to y if $(CC) supports the -m32
-	option. When $(biarch) equals 'y', the expanded variables $(aflags-y)
-	and $(cflags-y) will be assigned the values -a32 and -m32,
-	respectively.
-	Note: cc-option-yn uses KBUILD_CFLAGS for $(CC) options
+	Or::
+
+		ifeq ($(call cc-option,$(FLAG)),)
+		# $(FLAG) is not supported
 
     cc-disable-warning
 	cc-disable-warning checks if gcc supports a given warning and returns
diff --git a/scripts/Makefile.compiler b/scripts/Makefile.compiler
index 86ecd2ac874c..c19c0b544c0f 100644
--- a/scripts/Makefile.compiler
+++ b/scripts/Makefile.compiler
@@ -51,11 +51,6 @@ __cc-option = $(call try-run,\
 cc-option = $(call __cc-option, $(CC),\
 	$(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS),$(1),$(2))
 
-# cc-option-yn
-# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
-cc-option-yn = $(call try-run,\
-	$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
-
 # cc-disable-warning
 # Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
 cc-disable-warning = $(call try-run,\
-- 
2.33.0.rc1.237.g0d66db33f3-goog

Re: [PATCH 7/7] kbuild: remove cc-option-yn, update Docs

[Nathan Chancellor]

On 8/16/2021 5:21 PM, 'Nick Desaulniers' via Clang Built Linux wrote:
> cc-option-yn can be replaced with cc-option. ie.
> Checking for support:
> ifeq ($(call cc-option-yn,$(FLAG)),y)
> becomes:
> ifneq ($(call cc-option,$(FLAG)),)
> 
> Checking for lack of support:
> ifeq ($(call cc-option-yn,$(FLAG)),n)
> becomes:
> ifeq ($(call cc-option,$(FLAG)),)
> 
> This allows us to remove cc-option-yn. Do so and update the docs with
> examples.
> 
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

> ---
>   Documentation/kbuild/makefiles.rst | 22 +++++++++-------------
>   scripts/Makefile.compiler          |  5 -----
>   2 files changed, 9 insertions(+), 18 deletions(-)
> 
> diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst
> index db3af0b45baf..4538c36d8df0 100644
> --- a/Documentation/kbuild/makefiles.rst
> +++ b/Documentation/kbuild/makefiles.rst
> @@ -650,24 +650,20 @@ more details, with real examples.
>   	-march=pentium-mmx if supported by $(CC), otherwise -march=i586.
>   	The second argument to cc-option is optional, and if omitted,
>   	cflags-y will be assigned no value if first option is not supported.
> -	Note: cc-option uses KBUILD_CFLAGS for $(CC) options
> +	Note: cc-option uses KBUILD_CFLAGS for $(CC) options.
>   
> -   cc-option-yn
> -	cc-option-yn is used to check if gcc supports a given option
> -	and return 'y' if supported, otherwise 'n'.
> +	cc-option can be combined with conditionals to perform actions based on tool
> +	support.
>   
>   	Example::
>   
> -		#arch/ppc/Makefile
> -		biarch := $(call cc-option-yn, -m32)
> -		aflags-$(biarch) += -a32
> -		cflags-$(biarch) += -m32
> +		ifneq ($(call cc-option,$(FLAG)),)
> +		# $(FLAG) is supported
>   
> -	In the above example, $(biarch) is set to y if $(CC) supports the -m32
> -	option. When $(biarch) equals 'y', the expanded variables $(aflags-y)
> -	and $(cflags-y) will be assigned the values -a32 and -m32,
> -	respectively.
> -	Note: cc-option-yn uses KBUILD_CFLAGS for $(CC) options
> +	Or::
> +
> +		ifeq ($(call cc-option,$(FLAG)),)
> +		# $(FLAG) is not supported
>   
>       cc-disable-warning
>   	cc-disable-warning checks if gcc supports a given warning and returns
> diff --git a/scripts/Makefile.compiler b/scripts/Makefile.compiler
> index 86ecd2ac874c..c19c0b544c0f 100644
> --- a/scripts/Makefile.compiler
> +++ b/scripts/Makefile.compiler
> @@ -51,11 +51,6 @@ __cc-option = $(call try-run,\
>   cc-option = $(call __cc-option, $(CC),\
>   	$(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS),$(1),$(2))
>   
> -# cc-option-yn
> -# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
> -cc-option-yn = $(call try-run,\
> -	$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
> -
>   # cc-disable-warning
>   # Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable)
>   cc-disable-warning = $(call try-run,\
>