diff mbox series

[v2,20/20] arm64: vdso32: Enable Clang Compilation

Message ID 20200306133242.26279-21-vincenzo.frascino@arm.com (mailing list archive)
State Superseded
Headers show
Series Introduce common headers | expand

Commit Message

Vincenzo Frascino March 6, 2020, 1:32 p.m. UTC 
Enable Clang Compilation for the vdso32 library.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
 arch/arm64/kernel/vdso32/Makefile | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

Comments

Nathan Chancellor March 10, 2020, 1:40 a.m. UTC | #1 
On Fri, Mar 06, 2020 at 01:32:42PM +0000, Vincenzo Frascino wrote:
> Enable Clang Compilation for the vdso32 library.
> 
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
> ---
>  arch/arm64/kernel/vdso32/Makefile | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/kernel/vdso32/Makefile b/arch/arm64/kernel/vdso32/Makefile
> index 04df57b43cb1..650cfc5757eb 100644
> --- a/arch/arm64/kernel/vdso32/Makefile
> +++ b/arch/arm64/kernel/vdso32/Makefile
> @@ -10,7 +10,18 @@ include $(srctree)/lib/vdso/Makefile
>  
>  # Same as cc-*option, but using CC_COMPAT instead of CC
>  ifeq ($(CONFIG_CC_IS_CLANG), y)
> -CC_COMPAT ?= $(CC)
> +COMPAT_GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE_COMPAT)elfedit))
> +COMPAT_GCC_TOOLCHAIN := $(realpath $(COMPAT_GCC_TOOLCHAIN_DIR)/..)
> +
> +CLANG_CC_COMPAT := $(CC)
> +CLANG_CC_COMPAT += --target=$(notdir $(CROSS_COMPILE_COMPAT:%-=%))
> +CLANG_CC_COMPAT += --prefix=$(COMPAT_GCC_TOOLCHAIN_DIR)
> +CLANG_CC_COMPAT += -no-integrated-as -Qunused-arguments
> +ifneq ($(COMPAT_GCC_TOOLCHAIN),)
> +CLANG_CC_COMPAT += --gcc-toolchain=$(COMPAT_GCC_TOOLCHAIN)
> +endif
> +
> +CC_COMPAT ?= $(CLANG_CC_COMPAT)
>  else
>  CC_COMPAT ?= $(CROSS_COMPILE_COMPAT)gcc
>  endif
> -- 
> 2.25.1
> 
If CC_COMPAT is ever specified on the command line as clang (maybe by
some unsuspecting user), we'd loose all of the above flags. Maybe it
would be better to build a set of COMPAT_CLANG_FLAGS and append them to
CC_COMPAT, maybe like below?

Regardless, the current approach works in my testing with clang 9.0.1
and master (clang 11.0.0). This patch specifically is:

Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com> # build

==================================================================================

diff --git a/arch/arm64/kernel/vdso32/Makefile b/arch/arm64/kernel/vdso32/Makefile
index 650cfc5757eb..df5145fab287 100644
--- a/arch/arm64/kernel/vdso32/Makefile
+++ b/arch/arm64/kernel/vdso32/Makefile
@@ -13,15 +13,16 @@ ifeq ($(CONFIG_CC_IS_CLANG), y)
 COMPAT_GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE_COMPAT)elfedit))
 COMPAT_GCC_TOOLCHAIN := $(realpath $(COMPAT_GCC_TOOLCHAIN_DIR)/..)
 
-CLANG_CC_COMPAT := $(CC)
-CLANG_CC_COMPAT += --target=$(notdir $(CROSS_COMPILE_COMPAT:%-=%))
-CLANG_CC_COMPAT += --prefix=$(COMPAT_GCC_TOOLCHAIN_DIR)
-CLANG_CC_COMPAT += -no-integrated-as -Qunused-arguments
+COMPAT_CLANG_FLAGS := --target=$(notdir $(CROSS_COMPILE_COMPAT:%-=%))
+COMPAT_CLANG_FLAGS += --prefix=$(COMPAT_GCC_TOOLCHAIN_DIR)
+COMPAT_CLANG_FLAGS += -no-integrated-as -Qunused-arguments
 ifneq ($(COMPAT_GCC_TOOLCHAIN),)
-CLANG_CC_COMPAT += --gcc-toolchain=$(COMPAT_GCC_TOOLCHAIN)
+COMPAT_CLANG_FLAGS += --gcc-toolchain=$(COMPAT_GCC_TOOLCHAIN)
 endif
 
-CC_COMPAT ?= $(CLANG_CC_COMPAT)
+CC_COMPAT ?= $(CC)
+CC_COMPAT += $(COMPAT_CLANG_FLAGS)
+
 else
 CC_COMPAT ?= $(CROSS_COMPILE_COMPAT)gcc
 endif
Vincenzo Frascino March 13, 2020, 12:01 p.m. UTC | #2 
On 3/10/20 1:40 AM, Nathan Chancellor wrote:
> On Fri, Mar 06, 2020 at 01:32:42PM +0000, Vincenzo Frascino wrote:
>> Enable Clang Compilation for the vdso32 library.
>>
>> Cc: Catalin Marinas <catalin.marinas@arm.com>
>> Cc: Will Deacon <will@kernel.org>
>> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
>> ---
>>  arch/arm64/kernel/vdso32/Makefile | 13 ++++++++++++-
>>  1 file changed, 12 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm64/kernel/vdso32/Makefile b/arch/arm64/kernel/vdso32/Makefile
>> index 04df57b43cb1..650cfc5757eb 100644
>> --- a/arch/arm64/kernel/vdso32/Makefile
>> +++ b/arch/arm64/kernel/vdso32/Makefile
>> @@ -10,7 +10,18 @@ include $(srctree)/lib/vdso/Makefile
>>  
>>  # Same as cc-*option, but using CC_COMPAT instead of CC
>>  ifeq ($(CONFIG_CC_IS_CLANG), y)
>> -CC_COMPAT ?= $(CC)
>> +COMPAT_GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE_COMPAT)elfedit))
>> +COMPAT_GCC_TOOLCHAIN := $(realpath $(COMPAT_GCC_TOOLCHAIN_DIR)/..)
>> +
>> +CLANG_CC_COMPAT := $(CC)
>> +CLANG_CC_COMPAT += --target=$(notdir $(CROSS_COMPILE_COMPAT:%-=%))
>> +CLANG_CC_COMPAT += --prefix=$(COMPAT_GCC_TOOLCHAIN_DIR)
>> +CLANG_CC_COMPAT += -no-integrated-as -Qunused-arguments
>> +ifneq ($(COMPAT_GCC_TOOLCHAIN),)
>> +CLANG_CC_COMPAT += --gcc-toolchain=$(COMPAT_GCC_TOOLCHAIN)
>> +endif
>> +
>> +CC_COMPAT ?= $(CLANG_CC_COMPAT)
>>  else
>>  CC_COMPAT ?= $(CROSS_COMPILE_COMPAT)gcc
>>  endif
>> -- 
>> 2.25.1
>>
> If CC_COMPAT is ever specified on the command line as clang (maybe by
> some unsuspecting user), we'd loose all of the above flags. Maybe it
> would be better to build a set of COMPAT_CLANG_FLAGS and append them to
> CC_COMPAT, maybe like below?
>

Fine by me.

> Regardless, the current approach works in my testing with clang 9.0.1
> and master (clang 11.0.0). This patch specifically is:
> 

Good to hear. I will add your tags to the patch.

> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
> Tested-by: Nathan Chancellor <natechancellor@gmail.com> # build
> 
> ==================================================================================
> 
> diff --git a/arch/arm64/kernel/vdso32/Makefile b/arch/arm64/kernel/vdso32/Makefile
> index 650cfc5757eb..df5145fab287 100644
> --- a/arch/arm64/kernel/vdso32/Makefile
> +++ b/arch/arm64/kernel/vdso32/Makefile
> @@ -13,15 +13,16 @@ ifeq ($(CONFIG_CC_IS_CLANG), y)
>  COMPAT_GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE_COMPAT)elfedit))
>  COMPAT_GCC_TOOLCHAIN := $(realpath $(COMPAT_GCC_TOOLCHAIN_DIR)/..)
>  
> -CLANG_CC_COMPAT := $(CC)
> -CLANG_CC_COMPAT += --target=$(notdir $(CROSS_COMPILE_COMPAT:%-=%))
> -CLANG_CC_COMPAT += --prefix=$(COMPAT_GCC_TOOLCHAIN_DIR)
> -CLANG_CC_COMPAT += -no-integrated-as -Qunused-arguments
> +COMPAT_CLANG_FLAGS := --target=$(notdir $(CROSS_COMPILE_COMPAT:%-=%))
> +COMPAT_CLANG_FLAGS += --prefix=$(COMPAT_GCC_TOOLCHAIN_DIR)
> +COMPAT_CLANG_FLAGS += -no-integrated-as -Qunused-arguments
>  ifneq ($(COMPAT_GCC_TOOLCHAIN),)
> -CLANG_CC_COMPAT += --gcc-toolchain=$(COMPAT_GCC_TOOLCHAIN)
> +COMPAT_CLANG_FLAGS += --gcc-toolchain=$(COMPAT_GCC_TOOLCHAIN)
>  endif
>  
> -CC_COMPAT ?= $(CLANG_CC_COMPAT)
> +CC_COMPAT ?= $(CC)
> +CC_COMPAT += $(COMPAT_CLANG_FLAGS)
> +
>  else
>  CC_COMPAT ?= $(CROSS_COMPILE_COMPAT)gcc
>  endif
>
diff mbox series

Patch

diff --git a/arch/arm64/kernel/vdso32/Makefile b/arch/arm64/kernel/vdso32/Makefile
index 04df57b43cb1..650cfc5757eb 100644
--- a/arch/arm64/kernel/vdso32/Makefile
+++ b/arch/arm64/kernel/vdso32/Makefile
@@ -10,7 +10,18 @@  include $(srctree)/lib/vdso/Makefile
 
 # Same as cc-*option, but using CC_COMPAT instead of CC
 ifeq ($(CONFIG_CC_IS_CLANG), y)
-CC_COMPAT ?= $(CC)
+COMPAT_GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE_COMPAT)elfedit))
+COMPAT_GCC_TOOLCHAIN := $(realpath $(COMPAT_GCC_TOOLCHAIN_DIR)/..)
+
+CLANG_CC_COMPAT := $(CC)
+CLANG_CC_COMPAT += --target=$(notdir $(CROSS_COMPILE_COMPAT:%-=%))
+CLANG_CC_COMPAT += --prefix=$(COMPAT_GCC_TOOLCHAIN_DIR)
+CLANG_CC_COMPAT += -no-integrated-as -Qunused-arguments
+ifneq ($(COMPAT_GCC_TOOLCHAIN),)
+CLANG_CC_COMPAT += --gcc-toolchain=$(COMPAT_GCC_TOOLCHAIN)
+endif
+
+CC_COMPAT ?= $(CLANG_CC_COMPAT)
 else
 CC_COMPAT ?= $(CROSS_COMPILE_COMPAT)gcc
 endif