Re: [Qemu-devel] [PATCH] build: allow automatic git submodule updates to be disabled

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 27/10/17 00:04, Daniel P. Berrange wrote:
> Some people building QEMU use VPATH builds where the source directory is on a
> read-only volume. In such a case 'scripts/git-submodules.sh update' will always
> fail and users are required to run it manually themselves on their original
> writable source directory.
> 
> While this is already supported, it is nice to give users a command line flag
> to configure to permanently disable automatic submodule updates, as it means
> they won't get hard to diagnose failures from git-submodules.sh at an arbitrary
> later date.
> 
> This patch thus introduces a flag '--disable-git-update' which will prevent
> 'make' from ever running 'scripts/git-submodules.sh update'. It will still run
> the 'status' command to determine if a submodule update is needed, but when it
> does this it'll simply stop and print a message instructing the developer what
> todo. eg
> 
> $ ./configure  --target-list=x86_64-softmmu --disable-git-update
> ...snip...
> 
> $ make
>   GEN     config-host.h
>   GEN     trace/generated-tcg-tracers.h
>   GEN     trace/generated-helpers-wrappers.h
>   GEN     trace/generated-helpers.h
>   GEN     trace/generated-helpers.c
>   GEN     module_block.h
> 
> GIT submodule checkout is out of date. Please run
>   scripts/git-submodule.sh update ui/keycodemapdb
> from the source directory checkout /home/berrange/src/virt/qemu
> 
> make: *** [Makefile:31: git-submodule-update] Error 1
> 
> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
> ---
>  Makefile  | 11 +++++++++++
>  configure |  9 ++++++++-
>  2 files changed, 19 insertions(+), 1 deletion(-)
> 
> diff --git a/Makefile b/Makefile
> index 4c9d0eaef2..cefb75dc8d 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -26,12 +26,23 @@ ifeq (0,$(MAKELEVEL))
>    )
>  
>  ifeq (1,$(git_module_status))
> +ifeq (no,$(GIT_UPDATE))
> +git-submodule-update:
> +	$(call quiet-command, \
> +            echo && \
> +            echo "GIT submodule checkout is out of date. Please run" && \
> +            echo "  scripts/git-submodule.sh update $(GIT_SUBMODULES)" && \
> +            echo "from the source directory checkout $(SRC_PATH)" && \


I'd love to see this warning when $GIT_UPDATE!=no too. Now it is:

  GIT     ui/keycodemapdb dtc
./scripts/git-submodule.sh: 36: ./scripts/git-submodule.sh: cannot create
.git-submodule-status: Read-only file system
Makefile:40: recipe for target 'git-submodule-update' failed


Other than that, looks nice, thanks for fixing it.



-- 
Alexey