kbuild: sync scripts/Kbuild.include with Linux 5.7-rc2 ...

More random cherry-picks for scripts/Kbuild.include

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: sync if_changed and friends with Linux 5.7-rc2 ...

Resync cmd, if_change, if_changed_dep, and if_changed_rule.

Clean up the users of if_changed_rule.

I deleted the modversions rule. It is dead code because barebox
does not define CONFIG_MODVERSIONS. It does not work without
scripts/genksyms/ anyway.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: sync filechk rule with Linux 5.7-rc2 ...

The 'filechk' in the latest Linux works more simply, reliably.

- Do not show CHK every time
- Delete the *.tmp file when the filechk_$(1) fails
- Do not open the first prerequisite. This is unneeded in most cases.

I deleted pointeless dependency on Makefile.

Also delete the meaningless assignment to 'targets' because filechk
does not generate .cmd file.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: prefix compiler flag variables with KBUILD_ ...

In old days, Linux also used to use well-known variables such CFLAGS,
CPPFLAGS, etc.

They were prefixed with KBUILD_ presumably for preventing users from
overriding them accidentally.

Rename as follows:
  CFLAGS          ->  KBUILD_CFLAGS
  AFLAGS          ->  KBUILD_AFLAGS
  CPPFLAGS        ->  KBUILD_CPPFLAGS
  LDFLAGS         ->  KBUILD_LDFLAGS
  HOSTCFLAGS      ->  KBUILD_HOSTCFLAGS
  HOSTCXXFLAGS    ->  KBUILD_HOSTCXXFLAGS
  HOSTLDFLAGS     ->  KBUILD_HOSTLDFLAGS
  HOST_LOADLIBES  ->  KBUILD_HOSTLDLIBS

HOSTCFLAGS, HOSTCXXFLAGS, HOSTLDFLAGS, HOSTLDLIBS are re-used to allow
users to pass-in additional flags to the host compiler.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: remove ar-option ...

Linux commit 13dc8c029cab ("kbuild: remove ar-option and KBUILD_ARFLAGS")
removed this already.

Barebox has never used this macro.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Merge branch 'for-next/rsa'

Kbuild: Add config_filename macro from kernel ...

The config_filename allows to extract a filename from a Kconfig string
option.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild, LLVMLinux: Add -Werror to cc-option to support clang ...

Clang will warn about unknown warnings but will not return false
unless -Werror is set. GCC will return false if an unknown
warning is passed.

Adding -Werror make both compiler behave the same.

[arnd: it turns out we need the same patch for testing whether -ffunction-sections
       works right with gcc. I've build tested extensively with this patch
       applied, so let's just merge this one now.]

Signed-off-by: Mark Charlebois <charlebm@gmail.com>
Signed-off-by: Behan Webster <behanw@converseincode.com>
Reviewed-by: Jan-Simon Möller <dl9pf@gmx.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
[afa: ported to barebox from upstream c3f0d0bc5b01ad9]
Signed-off-by: Ahmad Fatoum <ahmad@a3f.at>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: do not drop -I without parameter ...

Linux commit 48f6e3c
[ Adjusted for barebox for some missing commits ]

The comment line for addtree says "skip if -I has no parameter".

What it actually does is "drop if -I has no parameter".  For example,
if you have the compiler flag '-I foo' (a space between), it will be
converted to 'foo'.  This completely changes the meaning.

What we want is, "do nothing" for -I without parameter so that
'-I foo' is kept as-is.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: drop support for cc-ldoption ...

Barebox is not using this macro.

Linux commit 055efab killed this
macro, so let's remove it from barebox too.

I see another cc-ldoption in dts/scripts/Kbuild.include, but did not
touch it. In my understanding, the dts/ directory is synced with the
upstream devicetree-rebasing project [1].

[1] git://git.kernel.org/pub/scm/linux/kernel/git/devicetree/devicetree-rebasing.git

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: cherry-pick changes from Linux v5.0-rc3 ...

Not synced completely.

Just cherry-picking low-hanging fruits.

  0b35786d77ba  kbuild: call make once for all targets when O=.. is used
  5e54d5e5fbc1  kbuild: kill EXTRA_ARFLAGS
  836caba77c29  kbuild: kill backward compatibility checks
  3156fd0529b5  kbuild: fix some minor typoes
  b8b0618cf6fa  kbuild: remove extra ifdef/endif of top Makefile
  16f890988114  kbuild: Remove reference to uninitialised variable
  9319f4539c18  kbuild: support simultaneous "make %config" and "make all"
  9d5db8949f1e  scripts/Makefile.clean: clean also $(extra-m) and $(extra-)
  a4954fd7724c  kbuild: remove obj-n and lib-n handling
  371fdc77af44  kbuild: collect shorthands into scripts/Kbuild.include
  a29b82326ed4  kbuild: Remove duplicate $(cmd) definition in Makefile.clean
  a1e7b7bb1ab5  Makefile: sort list of defconfig targets in make help output
  34948e0bbf98  kbuild: Drop support for clean-rule
  4218affdf57f  kbuild: remove warning about "make depend"
  9c8fa9bc08f6  kbuild: fix if_change and friends to consider argument order
  39a33ff80a25  kbuild: remove cc-option-align
  a7f924190924  kbuild: add %.dtb.S and %.dtb to 'targets' automatically
  54a702f70589  kbuild: mark $(targets) as .SECONDARY and remove .PRECIOUS markers
  9564a8cf422d  Kbuild: fix # escaping in .cmd files for future Make
  bd412d81b7ea  kbuild: .PHONY is not a variable, but PHONY is
  6916162c7308  kbuild: remove duplicated comments about PHONY
  d6c6ab93e17f  kbuild: remove deprecated host-progs variable
  7d0ea2524202  kbuild: use 'else ifeq' for checksrc to improve readability
  3f80babd9ca4  kbuild: remove unused cc-fullversion variable
  bd352a739fde  kbuild: remove unused baseprereq
  b421b8a6cb87  kbuild: remove unused archmrproper

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: add .SECONDARY special target ...

Based on the following Linux commits:

 - 54a702f70589 ("kbuild: mark $(targets) as .SECONDARY and remove
   .PRECIOUS markers")

 - 8e9b61b293d9 ("kbuild: move .SECONDARY special target to
   Kbuild.include")

This consolidates those two commits and adjusts commit log for barebox.

GNU Make automatically deletes intermediate files that are updated
in a chain of pattern rules.

Example 1) %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
Example 2) %.o <- %.c <- %.c_shipped

arch/arm/crypto/Makefile marks such targets as .PRECIOUS to prevent Make
from deleting them, but the correct way is to use .SECONDARY.

  .SECONDARY
    Prerequisites of this special target are treated as intermediate
    files but are never automatically deleted.

  .PRECIOUS
    When make is interrupted during execution, it may delete the target
    file it is updating if the file was modified since make started.
    If you mark the file as precious, make will never delete the file
    if interrupted.

Both can avoid deletion of intermediate files, but the difference is
the behavior when Make is interrupted; .SECONDARY deletes the target,
but .PRECIOUS does not.

The use of .PRECIOUS is relatively rare since we do not want to keep
partially constructed (possibly corrupted) targets.

.SECONDARY with no prerequisites causes all targets to be treated as
secondary. This agrees the policy of Kbuild.

scripts/Kbuild.include seems a suitable place to add it because it is
included from almost all sub-makes.

I deleted 'SECONDARY' (no dot) from images/Makefile, which I guess
a typo.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

kbuild: add .DELETE_ON_ERROR special target ...

Linux commit 9c2af1c

If Make gets a fatal signal while a shell is executing, it may delete
the target file that the recipe was supposed to update.  This is needed
to make sure that it is remade from scratch when Make is next run; if
Make is interrupted after the recipe has begun to write the target file,
it results in an incomplete file whose time stamp is newer than that
of the prerequisites files.  Make automatically deletes the incomplete
file on interrupt unless the target is marked .PRECIOUS.

The situation is just the same as when the shell fails for some reasons.
Usually when a recipe line fails, if it has changed the target file at
all, the file is corrupted, or at least it is not completely updated.
Yet the file’s time stamp says that it is now up to date, so the next
time Make runs, it will not try to update that file.

However, Make does not cater to delete the incomplete target file in
this case.  We need to add .DELETE_ON_ERROR somewhere in the Makefile
to request it.

scripts/Kbuild.include seems a suitable place to add it because it is
included from almost all sub-makes.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Kbuild: Add $(quote) ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

build: fix that LZO file is always rebuilt ...

From e398a00 Mon Sep 17 00:00:00 2001
From: Sam Ravnborg <sam@ravnborg.org>
Date: Tue, 26 Dec 2017 18:09:35 +0100
Subject: [PATCH 4/4] build: fix that LZO file is always rebuilt

Port the make-cmd from linux kernel.
with the updated version $$ is porperly escaped, thus
the LZO rule works as intended.
And we avoid rebuilds when not required

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Fix linking with new ld, based on u-boot ...

U-boot commit info:
http://git.denx.de/?p=u-boot.git;a=commit;h=e391b1e

Signed-off-by: Andrey Panov <rockford@yandex.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Make: Fix if_changed when command contains backslashes ...

The call if_changed mechanism does not work when the command
contains backslashes. This basically is an issue with lzo
and bzip2 compressed kernels. The compressed binaries do not
contain the uncompressed image size, so these use size_append
to append the size. This results in backslashes in the executed
command. With this if_changed always detects a change in the
command and rebuilds the compressed image even if nothing
has changed.

Fix this by escaping backslashes in make-cmd

This was worked out together with Jan Lübbe. The same patch
has recently been accepted to the kernel.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Jan Luebbe <jlu@pengutronix.de>

scripts/Kbuild.include: update to latest kernel version ...

To get cc-disable-warning

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

svn_rev_008 ...

add missing Kconfig