Re: [RFC kvm-unit-tests PATCH 7/8] Makefiles: fix up the x86 build include and link paths

From: Andrew Jones <drjones@redhat.com>
To: "Alex Bennée" <alex.bennee@linaro.org>
Cc: pbonzini@redhat.com, kvm@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu, christoffer.dall@linaro.org,
	marc.zyngier@arm.com
Subject: Re: [RFC kvm-unit-tests PATCH 7/8] Makefiles: fix up the x86 build include and link paths
Date: Fri, 7 Apr 2017 15:31:52 +0200	[thread overview]
Message-ID: <20170407133152.j4lrz43cj4vkl7ox@kamzik.brq.redhat.com> (raw)
In-Reply-To: <20170406190727.5624-8-alex.bennee@linaro.org>

On Thu, Apr 06, 2017 at 08:07:26PM +0100, Alex Bennée wrote:
> We still need to tell the compiler the correct search path for finding
> headers and the like. This is slightly complicated by the "dynamic"
> asm search path which is in our build tree but (may be) symlinked to
> the right architectures headers.
> 
> Also we explicitly include SRCDIR for the linking scripts as VPATH
> doesn't seem to find them well enough.
> 
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> ---
>  Makefile            |  2 +-
>  x86/Makefile.common | 10 +++++-----
>  2 files changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/Makefile b/Makefile
> index c9fea88..22da887 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -78,7 +78,7 @@ $(libcflat): $(cflatobjs)
>  	$(AR) rcs $@ $^
>  
>  include $(LIBFDT_srcdir)/Makefile.libfdt
> -$(LIBFDT_archive): CFLAGS += -ffreestanding -I lib -I lib/libfdt -Wno-sign-compare
> +$(LIBFDT_archive): CFLAGS += -ffreestanding -I $(SRCDIR)/lib -I $(SRCDIR)/lib/libfdt -Wno-sign-compare
>  $(LIBFDT_archive): $(addprefix $(LIBFDT_objdir)/,$(LIBFDT_OBJS))
>  	$(AR) rcs $@ $^
>  
> diff --git a/x86/Makefile.common b/x86/Makefile.common
> index ef6e543..032ed19 100644
> --- a/x86/Makefile.common
> +++ b/x86/Makefile.common
> @@ -17,7 +17,7 @@ cflatobjs += lib/x86/acpi.o
>  cflatobjs += lib/x86/stack.o
>  
>  $(libcflat): LDFLAGS += -nostdlib
> -$(libcflat): CFLAGS += -ffreestanding -I lib
> +$(libcflat): CFLAGS += -ffreestanding -I $(SRCDIR)/lib -I lib
>  
>  CFLAGS += -m$(bits)
>  CFLAGS += -O1
> @@ -31,8 +31,8 @@ libgcc := $(shell $(CC) -m$(bits) --print-libgcc-file-name)
>  .PRECIOUS: %.elf %.o
>  
>  FLATLIBS = lib/libcflat.a $(libgcc)
> -%.elf: %.o $(FLATLIBS) x86/flat.lds $(cstart.o)
> -	$(CC) $(CFLAGS) -nostdlib -o $@ -Wl,-T,x86/flat.lds \
> +%.elf: %.o $(FLATLIBS) $(SRCDIR)/x86/flat.lds $(cstart.o)
> +	$(CC) $(CFLAGS) -nostdlib -o $@ -Wl,-T,$(SRCDIR)/x86/flat.lds \
>  		$(filter %.o, $^) $(FLATLIBS)
>  
>  %.flat: %.elf
> @@ -60,10 +60,10 @@ scripts-common += $(TEST_DIR)/unittests.cfg
>  test_cases: $(tests-common) $(tests)
>  
>  
> -$(TEST_DIR)/%.o: CFLAGS += -std=gnu99 -ffreestanding -I lib -I lib/x86
> +$(TEST_DIR)/%.o: CFLAGS += -std=gnu99 -ffreestanding -I $(SRCDIR)/lib -I $(SRCDIR)/lib/x86 -I lib
>  
>  $(TEST_DIR)/realmode.elf: $(TEST_DIR)/realmode.o
> -	$(CC) -m32 -nostdlib -o $@ -Wl,-T,$(TEST_DIR)/realmode.lds $^
> +	$(CC) -m32 -nostdlib -o $@ -Wl,-T,$(SRCDIR)/$(TEST_DIR)/realmode.lds $^
>  
>  $(TEST_DIR)/realmode.o: bits = 32
>  
> -- 
> 2.11.0
>

I'm curious if we can drop this patch by telling VPATH about all the
directories: VPATH += $(SRCDIR)/$(TEST_DIR) $(SRCDIR)/lib ...

If so, then I think the earlier patch that sets VPATH to SRCDIR should
set it to the list of all common dirs, and the arch makefiles will += in
whatever else they need.

Thanks,
drew