[Buildroot] [PATCH] fs: allow filesystems to set the name of their output file

[Yann E. MORIN <yann.morin.1998@free.fr>]

Carlos, All,

On 2018-11-03 19:09 -0300, Carlos Santos spake thusly:
> Some filesystems may want to tweak their output names, rather than using
> the fixed "rootfs.foo" scheme. Add a ROOTFS_FOO_IMAGE_NAME variable for
> this purpose.
> 
> Signed-off-by: Carlos Santos <casantos@datacom.com.br>

I was a bit reluctant at replying to this third iteration, but as Thomas
asked for my opinion on IRC, here is my review...

I'll say it blundly: this patch does not work. It can't possibly have
been tested as-is.

> ---
> Supersedes: https://patchwork.ozlabs.org/patch/988843/
> Supersedes: https://patchwork.ozlabs.org/patch/988446/
> ---
> Changes v1->v2:
> - Prevent leading space when the filesystem gets 'imaginative', as
>   pointed by Yann Morin.
> Changes v2->v3:
> - Fix typo and use strip instead of qstrip, as spotted by Yann Morin.
> 
> NOTE: https://patchwork.ozlabs.org/patch/927116/ must be upated to
> document this.
> ---
>  fs/common.mk | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/fs/common.mk b/fs/common.mk
> index 453da6010a..175c3aca13 100644
> --- a/fs/common.mk
> +++ b/fs/common.mk
> @@ -106,6 +106,8 @@ rootfs-common-show-depends:
>  # all variable references except the arguments must be $$-quoted.
>  define inner-rootfs
>  
> +ROOTFS_$(2)_IMAGE_NAME ?= rootfs.$(1)
> +ROOTFS_$(2)_FINAL_IMAGE_NAME = $$(call strip,$$(ROOTFS_$(2)_IMAGE_NAME))

'strip' is not a macro, it is a built-in, so $(call)-ing it expands to
an empty string, so...

>  ROOTFS_$(2)_DIR = $$(FS_DIR)/$(1)
>  ROOTFS_$(2)_TARGET_DIR = $$(ROOTFS_$(2)_DIR)/target
>  
> @@ -140,10 +142,10 @@ ROOTFS_$(2)_COMPRESS_EXT = .xz
>  ROOTFS_$(2)_COMPRESS_CMD = xz -9 -C crc32 -c
>  endif
>  
> -$$(BINARIES_DIR)/rootfs.$(1): ROOTFS=$(2)
> -$$(BINARIES_DIR)/rootfs.$(1): FAKEROOT_SCRIPT=$$(ROOTFS_$(2)_DIR)/fakeroot
> -$$(BINARIES_DIR)/rootfs.$(1): $$(ROOTFS_$(2)_DEPENDENCIES)
> -	@$$(call MESSAGE,"Generating root filesystem image rootfs.$(1)")
> +$$(BINARIES_DIR)/$$(ROOTFS_$(2)_FINAL_IMAGE_NAME): ROOTFS=$(2)
> +$$(BINARIES_DIR)/$$(ROOTFS_$(2)_FINAL_IMAGE_NAME): FAKEROOT_SCRIPT=$$(ROOTFS_$(2)_DIR)/fakeroot
> +$$(BINARIES_DIR)/$$(ROOTFS_$(2)_FINAL_IMAGE_NAME): $$(ROOTFS_$(2)_DEPENDENCIES)

... these rules thus all have just $$(BINARIES_DIR) as their target, so
that doe not work very nicely...

> +	@$$(call MESSAGE,"Generating filesystem image $$(ROOTFS_$(2)_FINAL_IMAGE_NAME)")
>  	rm -rf $$(ROOTFS_$(2)_DIR)
>  	mkdir -p $$(ROOTFS_$(2)_DIR)
>  	echo '#!/bin/sh' > $$(FAKEROOT_SCRIPT)
> @@ -164,7 +166,7 @@ endif
>  rootfs-$(1)-show-depends:
>  	@echo $$(ROOTFS_$(2)_DEPENDENCIES)
>  
> -rootfs-$(1): $$(BINARIES_DIR)/rootfs.$(1)
> +rootfs-$(1): $$(BINARIES_DIR)/$$(ROOTFS_$(2)_FINAL_IMAGE_NAME)

... except maybe because of that?

Anyway, that is still an incorrect patch...

Regards,
Yann E. MORIN.

>  
>  .PHONY: rootfs-$(1) rootfs-$(1)-show-depends
>  
> -- 
> 2.17.1
> 

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