Re: [PATCH 1/3] handling of _shipped files

From: Randy Dunlap
Date: Wed Oct 01 2014 - 13:52:07 EST


On 10/01/14 06:36, Nicholas Mc Guire wrote:
>
> handling of _shipped files
>
> This adds a section on handling of _shipped files in kbuild
> Makefiles and the build process.
>
> Signed-off-by: Nicholas Mc Guire <der.herr@xxxxxxx>
> ---
> Documentation/kbuild/makefiles.txt | 57 +++++++++++++++++++++++++++++++++++-
> 1 file changed, 56 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt
> index 764f599..d0bd91a 100644
> --- a/Documentation/kbuild/makefiles.txt
> +++ b/Documentation/kbuild/makefiles.txt
> @@ -19,6 +19,7 @@ This document describes the Linux kernel Makefiles.
> --- 3.10 Special Rules
> --- 3.11 $(CC) support functions
> --- 3.12 $(LD) support functions
> + --- 3.13 _shipped - generated files
>
> === 4 Host Program support
> --- 4.1 Simple Host Program
> @@ -595,6 +596,60 @@ more details, with real examples.
> LDFLAGS_vmlinux += $(call ld-option, -X)
>
>
> +--- 3.13 _shipped - generated files
> +
> + Some sources in the kernel are generated by tools or special
> + purpose scrips so that the build process dependencies can be kept

scripts

> + at a resonable level. Also in cases where the translation is not

reasonable

> + configuration dependent but might impact build time _shipped files

build time,

> + may be added along with the actual sources to speed up the build
> + process.
> +
> + For standard tools like lex and yacc the make process will actually
> + generate the _shipped files (see scripts/Makefile.lib) and retain
> + them by marking them .PRECIOUS so they are not removed by the clean
> + targets.
> +
> + For non standard tools the generation of the _shipped file it self

non-standard itself

> + may be manually achived by building and then renaming. A makefile

achieved

> + target for generate the actual target file should to be provided

to generate

> + though and can be conditioned on an environment variable.

Most examples that I see just expect the Makefile to be modified to set
(or define) the variable.

> +
> + Example:
> + ifdef GENERATE_KEYMAP
> +
> + $(obj)/defkeymap.c: $(obj)/%.c: $(src)/%.map
> + loadkeys --mktable $< > $@
> +
> + endif
> +
> + The _shipped file does not appear in the actual Makefile, this is
> + handled by the rules found in scripts/Makefile.lib.
> +
> + <snip>
> + cmd_shipped = cat $< > $@
> +
> + $(obj)/%: $(src)/%_shipped
> + $(call cmd,shipped)
> + <snip>
> +
> + which simply will copy the target_shipped to the target
> +
> + If a file of a make target is found in the build directory with the
> + extension _shipped make will used it, rather than generating the

_shipped, make will use it rather than generating the

> + respective target file from source.
> +
> + The build will indicate the use of the _shipped file by the SHIPPED
> + quiet command in the make output.
> +
> + Example:
> + LD drivers/scsi/aic7xxx/built-in.o
> + SHIPPED drivers/scsi/aic7xxx/aic79xx_seq.h
> + SHIPPED drivers/scsi/aic7xxx/aic79xx_reg.h
> + CC [M] drivers/scsi/aic7xxx/aic79xx_core.o
> + CC [M] drivers/scsi/aic7xxx/aic79xx_pci.o
> + SHIPPED drivers/scsi/aic7xxx/aic79xx_reg_print.c
> + CC [M] drivers/scsi/aic7xxx/aic79xx_reg_print.o
> === 4 Host Program support
>
> Kbuild supports building executables on the host for use during the
> @@ -1423,10 +1478,10 @@ Original version made by Michael Elizabeth Chastain, <mailto:mec@xxxxxxxxx>
> Updates by Kai Germaschewski <kai@xxxxxxxxxxxxxxxxxxxxxx>
> Updates by Sam Ravnborg <sam@xxxxxxxxxxxx>
> Language QA by Jan Engelhardt <jengelh@xxxxxx>
> +Kbuild support for shipped files Nicholas Mc Guire <der.herr@xxxxxxx>
>
> === 11 TODO
>
> -- Describe how kbuild supports shipped files with _shipped.
> - Generating offset header files.
> - Add more variables to section 7?
>
>


--
~Randy
--
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