linux/arch/arm/boot/compressed
Masahiro Yamada 15d5761ad3 kbuild: introduce ccflags-remove-y and asflags-remove-y
CFLAGS_REMOVE_<file>.o filters out flags when compiling a particular
object, but there is no convenient way to do that for every object in
a directory.

Add ccflags-remove-y and asflags-remove-y to make it easily.

Use ccflags-remove-y to clean up some Makefiles.

The add/remove order works as follows:

 [1] KBUILD_CFLAGS specifies compiler flags used globally

 [2] ccflags-y adds compiler flags for all objects in the
     current Makefile

 [3] ccflags-remove-y removes compiler flags for all objects in the
     current Makefile (New feature)

 [4] CFLAGS_<file> adds compiler flags per file.

 [5] CFLAGS_REMOVE_<file> removes compiler flags per file.

Having [3] before [4] allows us to remove flags from most (but not all)
objects in the current Makefile.

For example, kernel/trace/Makefile removes $(CC_FLAGS_FTRACE)
from all objects in the directory, then adds it back to
trace_selftest_dynamic.o and CFLAGS_trace_kprobe_selftest.o

The same applies to lib/livepatch/Makefile.

Please note ccflags-remove-y has no effect to the sub-directories.
In contrast, the previous notation got rid of compiler flags also from
all the sub-directories.

The following are not affected because they have no sub-directories:

  arch/arm/boot/compressed/
  arch/powerpc/xmon/
  arch/sh/
  kernel/trace/

However, lib/ has several sub-directories.

To keep the behavior, I added ccflags-remove-y to all Makefiles
in subdirectories of lib/, except the following:

  lib/vdso/Makefile        - Kbuild does not descend into this Makefile
  lib/raid/test/Makefile   - This is not used for the kernel build

I think commit 2464a609de ("ftrace: do not trace library functions")
excluded too much. In the next commit, I will remove ccflags-remove-y
from the sub-directories of lib/.

Suggested-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Acked-by: Brendan Higgins <brendanhiggins@google.com> (KUnit)
Tested-by: Anders Roxell <anders.roxell@linaro.org>
2020-08-10 01:32:59 +09:00
..
.gitignore ARM: 8969/1: decompressor: simplify libfdt builds 2020-04-29 13:28:59 +01:00
atags_to_fdt.c ARM: 8969/1: decompressor: simplify libfdt builds 2020-04-29 13:28:59 +01:00
big-endian.S ARM: 8933/1: replace Sun/Solaris style flag on section directive 2019-11-15 22:21:19 +00:00
debug.S License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
decompress.c arch/arm/boot/compressed/decompress.c: fix build error due to lz4 changes 2019-06-01 15:51:31 -07:00
efi-header.S efi/libstub: Add missing prototype for PE/COFF entry point 2020-05-23 11:01:57 +02:00
fdt_ro.c ARM: 8969/1: decompressor: simplify libfdt builds 2020-04-29 13:28:59 +01:00
fdt_rw.c ARM: 8969/1: decompressor: simplify libfdt builds 2020-04-29 13:28:59 +01:00
fdt_wip.c ARM: 8969/1: decompressor: simplify libfdt builds 2020-04-29 13:28:59 +01:00
fdt.c ARM: 8969/1: decompressor: simplify libfdt builds 2020-04-29 13:28:59 +01:00
head-sa1100.S License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
head-sharpsl.S License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
head-xscale.S License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
head.S ARM: 8985/1: efi/decompressor: deal with HYP mode boot gracefully 2020-06-13 11:11:18 +01:00
ll_char_wr.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
Makefile kbuild: introduce ccflags-remove-y and asflags-remove-y 2020-08-10 01:32:59 +09:00
misc.c Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm 2018-04-09 09:19:30 -07:00
misc.h ARM: decompressor: fix warning introduced in fortify patch 2018-04-05 23:56:40 +01:00
piggy.S ARM: 8933/1: replace Sun/Solaris style flag on section directive 2019-11-15 22:21:19 +00:00
string.c ARM: boot: add strrchr function 2018-03-01 12:02:48 -06:00
vmlinux.lds.S ARM updates for 5.8-rc1: 2020-06-01 15:36:32 -07:00