[RFC kvm-unit-tests PATCH 6/8] Makefiles: handle linking of scripts into build-tree

[Alex Bennée]

Thomas Huth <thuth at redhat.com> writes:

> On 06.04.2017 21:07, Alex Bennée wrote:
>> When doing an out-of-src-tree build we still want access to the
>> various bits of common script machinery to run. This is handled by the
>> scripts-common list which sub-builds can add explicit extra stuff to.
>>
>> The final rule is conditional so we don't attempt to link files when
>> we are doing an in-src-tree build.
>>
>> Signed-off-by: Alex Bennée <alex.bennee at linaro.org>
>> ---
>>  Makefile            | 13 +++++++++++++
>>  x86/Makefile.common |  4 ++++
>>  2 files changed, 17 insertions(+)
>>
>> diff --git a/Makefile b/Makefile
>> index 56598df..c9fea88 100644
>> --- a/Makefile
>> +++ b/Makefile
>> @@ -31,6 +31,10 @@ cflatobjs := \
>>  	lib/report.o \
>>  	lib/stack.o
>>
>> +# These are scripts we want linked from the source tree
>> +scripts-common := run_tests.sh \
>> +	scripts
>> +
>>  # libfdt paths
>>  LIBFDT_objdir = $(SRCDIR)/lib/libfdt
>>  LIBFDT_srcdir = $(SRCDIR)/lib/libfdt
>> @@ -86,8 +90,17 @@ $(LIBFDT_archive): $(addprefix $(LIBFDT_objdir)/,$(LIBFDT_OBJS))
>>  	mkdir -p $(dir $@)
>>  	$(CC) $(CFLAGS) -c -o $@ $<
>>
>> +$(scripts-common): $(SRCDIR)/$@
>> +	ln -sf $<$@ $@
>
> The prerequisite does not seem to work correctly here. I can see that
> the symlinks are regenerated each time I run make. Even worse, during
> the second run, there is a
>
> ln -sf /home/thuth/devel/kvm-unit-tests/scripts scripts
>
> which generates a symlink in the source directory, since the "scripts"
> symlink already exists!
>
> I think you can not use automatic variables like $@ in the prerequisite
> list, can you?
>
> Maybe it would be better to create these symlinks in the configure
> script already?

Hmm maybe. The trouble is catching them all. That's why I wanted to have
something like scripts-common that sub Makefiles could add to.

We could certainly make the rule a bit more robust against re-linking
though.

>
>>  -include */.*.d */*/.*.d
>>
>> +
>> +# We only need to link common scripts for out-of-src-tree builds
>> +ifneq ($(CURDIR), $(SRCDIR))
>> +all: $(scripts-common)
>> +endif
>> +
>>  all: $(shell git -C $(SRCDIR) rev-parse --verify --short=8 HEAD >build-head 2>/dev/null)
>>
>>  standalone: all
>> diff --git a/x86/Makefile.common b/x86/Makefile.common
>> index fbab82c..ef6e543 100644
>> --- a/x86/Makefile.common
>> +++ b/x86/Makefile.common
>> @@ -54,8 +54,12 @@ tests-common += api/dirty-log
>>  tests-common += api/dirty-log-perf
>>  endif
>>
>> +scripts-common += $(TEST_DIR)/run
>> +scripts-common += $(TEST_DIR)/unittests.cfg
>> +
>>  test_cases: $(tests-common) $(tests)
>>
>> +
>
> Cosmetic nit: Superfluous white space change.
>
>>  $(TEST_DIR)/%.o: CFLAGS += -std=gnu99 -ffreestanding -I lib -I lib/x86
>>
>>  $(TEST_DIR)/realmode.elf: $(TEST_DIR)/realmode.o
>>
>
>  Thomas


--
Alex Bennée