Merge tag 'kbuild-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy...

Pull Kbuild updates from Masahiro Yamada:
 "Kbuild core:
   - remove unneeded $(call cc-option,...) switches
   - consolidate Clang compiler flags into CLANG_FLAGS
   - announce the deprecation of SUBDIRS
   - fix single target build for external module
   - simplify the dependencies of 'prepare' stage targets
   - allow fixdep to directly write to .*.cmd files
   - simplify dependency generation for CONFIG_TRIM_UNUSED_KSYMS
   - change if_changed_rule to accept multi-line recipe
   - move .SECONDARY special target to scripts/Kbuild.include
   - remove redundant 'set -e'
   - improve parallel execution for CONFIG_HEADERS_CHECK
   - misc cleanups

  Treewide fixes and cleanups
   - set Clang flags correctly for PowerPC boot images
   - fix UML build error with CONFIG_GCC_PLUGINS
   - remove unneeded patterns from .gitignore files
   - refactor firmware/Makefile
   - remove unneeded rules for *offsets.s
   - avoid unneeded regeneration of intermediate .s files
   - clean up ./Kbuild

  Modpost:
   - remove unused -M, -K options
   - fix false positive warnings about section mismatch
   - use simple devtable lookup instead of linker magic
   - misc cleanups

  Coccinelle:
   - relax boolinit.cocci checks for overall consistency
   - fix warning messages of boolinit.cocci

  Other tools:
   - improve -dirty check of scripts/setlocalversion
   - add a tool to generate compile_commands.json from .*.cmd files"

* tag 'kbuild-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (51 commits)
  kbuild: remove unused cmd_gentimeconst
  kbuild: remove $(obj)/ prefixes in ./Kbuild
  treewide: add intermediate .s files to targets
  treewide: remove explicit rules for *offsets.s
  firmware: refactor firmware/Makefile
  firmware: remove unnecessary patterns from .gitignore
  scripts: remove unnecessary ihex2fw and check-lc_ctypes from .gitignore
  um: remove unused filechk_gen_header in Makefile
  scripts: add a tool to produce a compile_commands.json file
  kbuild: add -Werror=implicit-int flag unconditionally
  kbuild: add -Werror=strict-prototypes flag unconditionally
  kbuild: add -fno-PIE flag unconditionally
  scripts: coccinelle: Correct warning message
  scripts: coccinelle: only suggest true/false in files that already use them
  kbuild: handle part-of-module correctly for *.ll and *.symtypes
  kbuild: refactor part-of-module
  kbuild: refactor quiet_modtag
  kbuild: remove redundant quiet_modtag for $(obj-m)
  kbuild: refactor Makefile.asm-generic
  user/Makefile: Fix typo and capitalization in comment section
  ...

diff --cc Makefile
index 7b4cfa4,b9e902e..60a4732
--- 1/Makefile
--- 2/Makefile
+++ b/Makefile
@@@ -1099,9 -1098,12 +1093,10 @@@ prepare2: prepare3 outputmakefile asm-g
  prepare1: prepare2 $(version_h) $(autoksyms_h) include/generated/utsrelease.h
        $(cmd_crmodverdir)
  
- archprepare: archheaders archscripts prepare1 scripts_basic
 -macroprepare: prepare1 archmacros
 -
 -archprepare: archheaders archscripts macroprepare scripts
++archprepare: archheaders archscripts prepare1 scripts
  
- prepare0: archprepare gcc-plugins
+ prepare0: archprepare
+       $(Q)$(MAKE) $(build)=scripts/mod
        $(Q)$(MAKE) $(build)=.
  
  # All the preparing..

diff --cc arch/arm/crypto/Makefile
Simple merge

diff --cc arch/arm/mach-omap2/Makefile
Simple merge

diff --cc arch/arm64/crypto/Makefile
Simple merge

diff --cc arch/powerpc/boot/Makefile
Simple merge

diff --cc samples/bpf/Makefile
Simple merge

diff --cc scripts/Kbuild.include
Simple merge

diff --cc scripts/Makefile.build
index 6a6be9f,0f2b5f0..fd03d60
--- 1/scripts/Makefile.build
--- 2/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@@ -236,16 -221,11 +221,9 @@@ ifdef CONFIG_GCOV_KERNE
  objtool_args += --no-unreachable
  endif
  ifdef CONFIG_RETPOLINE
 -ifneq ($(RETPOLINE_CFLAGS),)
    objtool_args += --retpoline
  endif
 -endif
  
- 
- ifdef CONFIG_MODVERSIONS
- objtool_o = $(@D)/.tmp_$(@F)
- else
- objtool_o = $(@)
- endif
- 
  # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
  # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
  # 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file

diff --cc scripts/Makefile.gcc-plugins
Simple merge

diff --cc scripts/Makefile.lib
Simple merge