Re: [RFC PATCH] tests/vm: avoid re-building the VM images all the time

["Alex Bennée" <alex.bennee@linaro.org>]

Alex Bennée <alex.bennee@linaro.org> writes:

> There are two problems.
>
> The first is a .PHONY target will always evaluate which triggers a
> full re-build of the VM images. Drop the requirement knowing that this
> introduces a manual step on freshly configure build dirs.
>
> The second is a minor unrelated tweak to the Makefile also triggers an
> expensive full re-build. Solve this be avoiding the dependency and
> putting a comment just above the bit that matters and hope developers
> notice the comment.
>
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
>
> ---
>
> This is hacky and sub-optimal. There surely must be a way to have our cake
> and eat it?
> ---
>  tests/vm/Makefile.include | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/tests/vm/Makefile.include b/tests/vm/Makefile.include
> index bf12e0fa3c5..a109773c588 100644
> --- a/tests/vm/Makefile.include
> +++ b/tests/vm/Makefile.include
> @@ -88,10 +88,11 @@ vm-build-all: $(addprefix vm-build-, $(IMAGES))
>  vm-clean-all:
>  	rm -f $(IMAGE_FILES)
>  
> +# Rebuilding the VMs every time this Makefile is tweaked is very
> +# expensive for most users. If you tweak the recipe bellow you will
> +# need to manually zap $(IMAGES_DIR)/%.img to rebuild.
>  $(IMAGES_DIR)/%.img:	$(SRC_PATH)/tests/vm/% \
> -			$(SRC_PATH)/tests/vm/basevm.py \
> -			$(SRC_PATH)/tests/vm/Makefile.include \
> -			$(VM_VENV)
> +			$(SRC_PATH)/tests/vm/basevm.py

Maybe:

 # need to manually zap $(IMAGES_DIR)/%.img to rebuild.
 $(IMAGES_DIR)/%.img:	$(SRC_PATH)/tests/vm/% \
 			$(SRC_PATH)/tests/vm/basevm.py
+	$(if $(VM_VENV), make $(VM_VENV))
 	@mkdir -p $(IMAGES_DIR)
 	$(call quiet-command, \

?


>  	@mkdir -p $(IMAGES_DIR)
>  	$(call quiet-command, \
>  		$(VM_PYTHON) $< \

-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro