Masahiro Yamada 07a422bb21 kbuild: restore autoksyms.h touch to the top Makefile
Commit d3fc425e819b ("kbuild: make sure autoksyms.h exists early")
moved the code that touches autoksyms.h to scripts/kconfig/Makefile
with obscure reason.

From Nicolas' comment [1], he did not seem to be sure about the root
cause.

I guess I figured it out, so here is a fix-up I think is more correct.
According to the error log in the original post [2], the build failed
in scripts/mod/devicetable-offsets.c

scripts/mod/Makefile is descended from scripts/Makefile, which is
invoked from the top-level Makefile by the 'scripts' target.

To build vmlinux and/or modules, Kbuild descend into $(vmlinux-dirs).
This depends on 'prepare' and 'scripts' as follows:

  $(vmlinux-dirs): prepare scripts

Because there is no dependency between 'prepare' and 'scripts', the
parallel building can execute them simultaneously.

'prepare' depends on 'prepare1', which touched autoksyms.h, while
'scripts' descends into script/, then scripts/mod/, which needs
<generated/autoksyms.h> if CONFIG_TRIM_UNUSED_KSYMS.  It was the
reason of the race.

I am not happy to have unrelated code in the Kconfig Makefile, so
getting it back to the top Makefile.

I removed the standalone test target because I want to use it to
create an empty autoksyms.h file.  Here is a little improvement;
unnecessary autoksyms.h is not created when CONFIG_TRIM_UNUSED_KSYMS
is disabled.

[1] https://lkml.org/lkml/2016/11/30/734
[2] https://lkml.org/lkml/2016/11/30/531

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
2018-03-26 02:01:22 +09:00
..
2018-02-09 04:10:10 +09:00
2018-03-02 00:26:47 +09:00
2018-02-09 04:10:10 +09:00
2005-04-16 15:20:36 -07:00
2018-01-22 00:49:29 +09:00
2018-03-02 00:26:47 +09:00
2018-03-02 00:26:47 +09:00
2018-01-22 00:49:29 +09:00
2018-02-10 11:26:04 +09:00
2015-10-14 14:59:03 +02:00
2018-03-02 00:26:47 +09:00
2018-03-02 00:26:47 +09:00