[U-Boot] [PATCH 0/2] fix building tools on FreeBSD/clang

[U-Boot] [PATCH 0/2] fix building tools on FreeBSD/clang

[Jeroen Hofstee]

Building tools from v2014.07-rc2 with clang as host cc produces
many warnings and fails on FreeBSD. The first patch removes the
warnings by restoring original behaviour. The second patch fixes
the build failure on FreeBSD by explicitly including the correct
header.

Jeroen Hofstee (2):
  Makefile: fix clang warnings due to clang support
  tools: include u-boot version of sha256.h

 Makefile       | 28 ----------------------------
 tools/Makefile |  1 +
 2 files changed, 1 insertion(+), 28 deletions(-)

-- 
1.8.3.2

[U-Boot] [PATCH 1/2] Makefile: fix clang warnings due to clang support

[Jeroen Hofstee]

Building u-boot tools with clang as a host compiler e.g. on
FreeBSD with `gmake HOSTCC=clang CONFIG_USE_PRIVATE_LIBGCC=y tools`
leads to many warnings [1] for every compiler invocation since
commit 598e2d33. Part of mentioned commit imports linux patches:

 - kbuild: LLVMLinux: Adapt warnings for compilation with clang
 - kbuild: LLVMLinux: Add Kbuild support for building kernel with Clang

No version of clang supports the gcc fno-delete-null-pointer-checks
though, but it is only passed to clang. Gcc does not have the clang
specific Qunused-arguments for the target. Furthermore several
warnings are disabled which aren't encountered in u-boot. Since such
a build has worked for quite some time and works after removing these
changes, just remove the clang specific handling to restore normal
building with clang as hostcc.

[1] Actual warnings
-------------------
  GEN     include/autoconf.mk.dep
arm-freebsd-gcc: unrecognized option '-Qunused-arguments'

  HOSTCC  scripts/basic/fixdep
clang: warning: argument unused during compilation:
                '-fno-delete-null-pointer-checks'

cc: Masahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
---
 Makefile | 28 ----------------------------
 1 file changed, 28 deletions(-)

diff --git a/Makefile b/Makefile
index e38fd2f..bde41aa 100644
--- a/Makefile
+++ b/Makefile
@@ -209,11 +209,6 @@ HOSTCXX      = g++
 HOSTCFLAGS   = -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer
 HOSTCXXFLAGS = -O2
 
-ifeq ($(shell $(HOSTCC) -v 2>&1 | grep -c "clang version"), 1)
-HOSTCFLAGS  += -Wno-unused-value -Wno-unused-parameter \
-		-Wno-missing-field-initializers -fno-delete-null-pointer-checks
-endif
-
 ifeq ($(HOSTOS),cygwin)
 HOSTCFLAGS	+= -ansi
 endif
@@ -320,15 +315,6 @@ endif
 
 export quiet Q KBUILD_VERBOSE
 
-ifneq ($(CC),)
-ifeq ($(shell $(CC) -v 2>&1 | grep -c "clang version"), 1)
-COMPILER := clang
-else
-COMPILER := gcc
-endif
-export COMPILER
-endif
-
 # Look for make include files relative to root of kernel src
 MAKEFLAGS += --include-dir=$(srctree)
 
@@ -545,20 +531,6 @@ endif
 
 KBUILD_CFLAGS += $(call cc-option,-fno-stack-protector)
 
-ifeq ($(COMPILER),clang)
-KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
-KBUILD_CPPFLAGS += $(call cc-option,-Wno-unknown-warning-option,)
-KBUILD_CFLAGS += $(call cc-disable-warning, unused-variable)
-KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
-KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
-# Quiet clang warning: comparison of unsigned expression < 0 is always false
-KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
-# CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
-# source of a reference will be _MergedGlobals and not on of the whitelisted names.
-# See modpost pattern 2
-KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)
-endif
-
 KBUILD_CFLAGS	+= -g
 # $(KBUILD_AFLAGS) sets -g, which causes gcc to pass a suitable -g<format>
 # option to the assembler.
-- 
1.8.3.2

[U-Boot] [PATCH 2/2] tools: include u-boot version of sha256.h

[Jeroen Hofstee]

When building tools the u-boot specific sha256.h is required, but the
host version of sha256.h is used when present. This leads to build errors
on FreeBSD which does have a system sha256.h include. Like libfdt_env.h
explicitly include u-boot's sha256.h.

cc: Simon Glass <sjg@chromium.org>
Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
---
 tools/Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/Makefile b/tools/Makefile
index 6e43a01..5105360 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -185,6 +185,7 @@ endif # !LOGO_BMP
 # Define _GNU_SOURCE to obtain the getline prototype from stdio.h
 #
 HOST_EXTRACFLAGS += -include $(srctree)/include/libfdt_env.h \
+		-include $(srctree)/include/sha256.h \
 		$(patsubst -I%,-idirafter%, $(UBOOTINCLUDE)) \
 		-I$(srctree)/lib/libfdt \
 		-I$(srctree)/tools \
-- 
1.8.3.2

[U-Boot] [PATCH 2/2] tools: include u-boot version of sha256.h

[Simon Glass]

On 30 May 2014 07:45, Jeroen Hofstee <jeroen@myspectrum.nl> wrote:
> When building tools the u-boot specific sha256.h is required, but the
> host version of sha256.h is used when present. This leads to build errors
> on FreeBSD which does have a system sha256.h include. Like libfdt_env.h
> explicitly include u-boot's sha256.h.
>
> cc: Simon Glass <sjg@chromium.org>
> Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>

There might be a general approach here, but this is just as reasonable
as the libfdt_env.h inclusion.

Acked-by: Simon Glass <sjg@chromium.org>

(tested with buildman - no build regressions on all boards)

> ---
>  tools/Makefile | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/tools/Makefile b/tools/Makefile
> index 6e43a01..5105360 100644
> --- a/tools/Makefile
> +++ b/tools/Makefile
> @@ -185,6 +185,7 @@ endif # !LOGO_BMP
>  # Define _GNU_SOURCE to obtain the getline prototype from stdio.h
>  #
>  HOST_EXTRACFLAGS += -include $(srctree)/include/libfdt_env.h \
> +               -include $(srctree)/include/sha256.h \
>                 $(patsubst -I%,-idirafter%, $(UBOOTINCLUDE)) \
>                 -I$(srctree)/lib/libfdt \
>                 -I$(srctree)/tools \
> --
> 1.8.3.2
>

[U-Boot] [PATCH 2/2] tools: include u-boot version of sha256.h

[Jeroen Hofstee]

Hello Simon,

On di, 2014-06-03 at 08:11 -0600, Simon Glass wrote:
> On 30 May 2014 07:45, Jeroen Hofstee <jeroen@myspectrum.nl> wrote:
> > When building tools the u-boot specific sha256.h is required, but the
> > host version of sha256.h is used when present. This leads to build errors
> > on FreeBSD which does have a system sha256.h include. Like libfdt_env.h
> > explicitly include u-boot's sha256.h.
> >
> > cc: Simon Glass <sjg@chromium.org>
> > Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
> 
> There might be a general approach here, but this is just as reasonable
> as the libfdt_env.h inclusion.
> 
> Acked-by: Simon Glass <sjg@chromium.org>
> 
> (tested with buildman - no build regressions on all boards)

Thanks for testing. One of the more generic solutions I considered is to
actually move all such headers to include/u-boot. I tried that, but it
rapidly becomes a big patch touching files in all archs, which is a bit
too big after an rc2 is already out.

Tom, since this does fix a build error, can you consider including this
in the next release? (and preferably "Makefile: fix clang warnings due
to clang support" as well, as it gains nothing but introduces quite some
compile noise [but is waiting for feedback from Masahiro]).

Regards,
Jeroen

[U-Boot] [PATCH 1/2] Makefile: fix clang warnings due to clang support

[Masahiro Yamada]

Hi Jeroen,


On Fri, 30 May 2014 15:45:27 +0200
Jeroen Hofstee <jeroen@myspectrum.nl> wrote:

> Building u-boot tools with clang as a host compiler e.g. on
> FreeBSD with `gmake HOSTCC=clang CONFIG_USE_PRIVATE_LIBGCC=y tools`
> leads to many warnings [1] for every compiler invocation since
> commit 598e2d33. Part of mentioned commit imports linux patches:
> 
>  - kbuild: LLVMLinux: Adapt warnings for compilation with clang
>  - kbuild: LLVMLinux: Add Kbuild support for building kernel with Clang
> 
> No version of clang supports the gcc fno-delete-null-pointer-checks
> though, but it is only passed to clang. Gcc does not have the clang
> specific Qunused-arguments for the target. Furthermore several
> warnings are disabled which aren't encountered in u-boot. Since such
> a build has worked for quite some time and works after removing these
> changes, just remove the clang specific handling to restore normal
> building with clang as hostcc.



I have to admit I just copied these line from Kernel
without testing it, just for syncing with Kernel makefiles.


As far as I tested, Clang did not recognize 
-fno-delete-null-pointer-checks.

It is OK with me if you rip Clang stuff off the top Makefile.

Sorry, honestly I am not familiar enough with Clang
to make deeper review.


This might be useful information for you.
some discussion why Linux folks added those lines:
https://patchwork.kernel.org/patch/3719881/

Do you also need this to use Clang?
https://patchwork.kernel.org/patch/3720041/


Best Regards
Masahiro Yamada

[U-Boot] [PATCH 1/2] Makefile: fix clang warnings due to clang support

[Jeroen Hofstee]

Hello Masahiro,

On di, 2014-06-10 at 21:20 +0900, Masahiro Yamada wrote:
> Hi Jeroen,
> 
> 
> On Fri, 30 May 2014 15:45:27 +0200
> Jeroen Hofstee <jeroen@myspectrum.nl> wrote:
> 
> > Building u-boot tools with clang as a host compiler e.g. on
> > FreeBSD with `gmake HOSTCC=clang CONFIG_USE_PRIVATE_LIBGCC=y tools`
> > leads to many warnings [1] for every compiler invocation since
> > commit 598e2d33. Part of mentioned commit imports linux patches:
> > 
> >  - kbuild: LLVMLinux: Adapt warnings for compilation with clang
> >  - kbuild: LLVMLinux: Add Kbuild support for building kernel with Clang
> > 
> > No version of clang supports the gcc fno-delete-null-pointer-checks
> > though, but it is only passed to clang. Gcc does not have the clang
> > specific Qunused-arguments for the target. Furthermore several
> > warnings are disabled which aren't encountered in u-boot. Since such
> > a build has worked for quite some time and works after removing these
> > changes, just remove the clang specific handling to restore normal
> > building with clang as hostcc.
> 
> 
> 
> I have to admit I just copied these line from Kernel
> without testing it, just for syncing with Kernel makefiles.
> 
> 
> As far as I tested, Clang did not recognize 
> -fno-delete-null-pointer-checks.
> 
> It is OK with me if you rip Clang stuff off the top Makefile.
> 
> Sorry, honestly I am not familiar enough with Clang
> to make deeper review.

yup, it should be removed.. since with clang 3.5 trunk it actually
errors. You should be able to verify it without cross target support
with:

`make CC="clang -no-integrated-as" HOSTCC="clang -no-integrated-as"
HOST_TOOLS_ALL=y sandbox_config tools`

and you get (with clang 3.5) "clang: error: unknown argument:
'-fno-delete-null-pointer-checks'" (and yes the commit mentions warns,
which more then likely is the case for clang 3.3 / 3.4). Undoing the
Linux clang additions (as this patch does) makes the build work again.

Since there is no target clang support in U-boot at the moment the
target warnings suppression can be removed as well, since it is just
dead code at the moment and I would like to see how far we can get with
actually fixing warnings, not blindly silencing them...

Regards,
Jeroen

[U-Boot] [U-Boot, 1/2] Makefile: fix clang warnings due to clang support

[Tom Rini]

On Fri, May 30, 2014 at 03:45:27PM +0200, Jeroen Hofstee wrote:

> Building u-boot tools with clang as a host compiler e.g. on
> FreeBSD with `gmake HOSTCC=clang CONFIG_USE_PRIVATE_LIBGCC=y tools`
> leads to many warnings [1] for every compiler invocation since
> commit 598e2d33. Part of mentioned commit imports linux patches:
> 
>  - kbuild: LLVMLinux: Adapt warnings for compilation with clang
>  - kbuild: LLVMLinux: Add Kbuild support for building kernel with Clang
> 
> No version of clang supports the gcc fno-delete-null-pointer-checks
> though, but it is only passed to clang. Gcc does not have the clang
> specific Qunused-arguments for the target. Furthermore several
> warnings are disabled which aren't encountered in u-boot. Since such
> a build has worked for quite some time and works after removing these
> changes, just remove the clang specific handling to restore normal
> building with clang as hostcc.
> 
> [1] Actual warnings
> -------------------
>   GEN     include/autoconf.mk.dep
> arm-freebsd-gcc: unrecognized option '-Qunused-arguments'
> 
>   HOSTCC  scripts/basic/fixdep
> clang: warning: argument unused during compilation:
>                 '-fno-delete-null-pointer-checks'
> 
> cc: Masahiro Yamada <yamada.m@jp.panasonic.com>
> Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>

Applied to u-boot/master, thanks!

-- 
Tom
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[U-Boot] [U-Boot, 2/2] tools: include u-boot version of sha256.h

[Tom Rini]

On Fri, May 30, 2014 at 03:45:28PM +0200, Jeroen Hofstee wrote:

> When building tools the u-boot specific sha256.h is required, but the
> host version of sha256.h is used when present. This leads to build errors
> on FreeBSD which does have a system sha256.h include. Like libfdt_env.h
> explicitly include u-boot's sha256.h.
> 
> cc: Simon Glass <sjg@chromium.org>
> Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
> Acked-by: Simon Glass <sjg@chromium.org>

Applied to u-boot/master, thanks!

-- 
Tom
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