[Skiboot] [PATCH] pflash: Clean up makefiles and resolve build race

[Stewart Smith]

Joel Stanley <joel at jms.id.au> writes:
> The pflash build process has regressed from when the were last fixed in
> 6c21c4ffaf82.
>
> This patch resolves that issue and performs some cleanups:
>
>  - Remove duplicated rules. Patches had moved rules into common files,
>    but forgotten to remove them from the pflash makefiles.
>
>  - Make assignements simply expanded variables where possible. Form the
>    make manual:
>
>      Functions referenced in the definition will be executed every time
>      the variable is expanded.  This makes make run slower; worse, it
>      causes the wildcard and shell functions to give unpredictable
>      results because you cannot easily control when they are called, or
>      even how many times.
>
>      To avoid all the problems and inconveniences of recursively
>      expanded variables, there is another flavor: simply expanded
>      variables.
>
>  - set the 'shared' target as a dependency of the libflash objects. This
>    was the final piece to resolve the race condition.
>
> The failed build could be reproduced by doing a `git clean -f -x` and
> then running the following:
>
>   $ make -j 32 CROSS_COMPILE=arm-linux-gnueabi- SKIBOOT_VERSION=5.2.4
>   PFLASH_VERSION=5.2.4 V=1 -C external/pflash all LINKAGE=dynamic
>   make: Entering directory '/home/joel/dev/skiboot/external/pflash'
>   ln -sf ../../libflash ./libflash
>   ln -sf ../../ccan ./ccan
>   ln -sf ../common ./common
>   cc -O2 -Wall -I. -c pflash.c -o pflash.o
>   cc -O2 -Wall -I. -c progress.c -o progress.o
>   make -C ../shared
>   make[1]: Entering directory '/home/joel/dev/skiboot/external/shared'
>   ln -sf ../../hw/ast-bmc/ast-sf-ctrl.c common/ast-sf-ctrl.c
>   ln -sf ../../include/ast.h common/ast.h
>   ln -sf arch_flash_arm_io.h common/io.h
>   cc -O2 -Wall -I.  -c common/arch_flash_common.c -o
>   common-arch_flash_common.o
>   cc -O2 -Wall -I.  -c common/arch_flash_arm.c -o common-arch_flash_arm.o
>   cc -O2 -Wall -I.  -c common/ast-sf-ctrl.c -o common-ast-sf-ctrl.o
>   cc -O2 -Wall -I. -c version.c -o version.o
>   ld -r common-arch_flash_common.o common-arch_flash_arm.o
>   common-ast-sf-ctrl.o -o common-arch_flash.o
>   ln -sf ../../libflash ./libflash
>   ln -sf ../../ccan ./ccan
>   ln -sf ../common ./common
>   make[1]: *** No rule to make target 'libflash/file.c', needed by
>   'libflash-file.o'.  Stop.
>   make[1]: *** Waiting for unfinished jobs....
>   make[1]: Leaving directory '/home/joel/dev/skiboot/external/shared'
>   rules.mk:25: recipe for target
>   '../shared/libflash.so.skiboot-5.2.4-1-g9f13f64c322f-joel-dirty-d5873ce'
>   failed
>   make: ***
>   [../shared/libflash.so.skiboot-5.2.4-1-g9f13f64c322f-joel-dirty-d5873ce]
>   Error 2
>
> Signed-off-by: Joel Stanley <joel at jms.id.au>
> ---
>
> Stewart, please apply to master and 5.2 stable.

Thanks, merged to both:

5.2.x: 8692215d6ff81a935e8086ccff6c05e9dc2cc6be
master: c327edd

-- 
Stewart Smith
OPAL Architect, IBM.