Merge tag 'kbuild-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - do not generate unneeded top-level built-in.a

 - let git ignore O= directory entirely

 - optimize scripts/kallsyms slightly

 - exclude DWARF info from *.s regardless of config options

 - fix GCC toolchain search path for Clang to prepare ld.lld support

 - do not generate modules.order when CONFIG_MODULES is disabled

 - simplify single target rules and remove VPATH for external module
   build

 - allow to add optional flags to dpkg-buildpackage when building
   deb-pkg

 - move some compiler option tests from Makefile to Kconfig

 - various Makefile cleanups

* tag 'kbuild-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (40 commits)
  kbuild: remove scripts/basic/% build target
  kbuild: use -Werror=implicit-... instead of -Werror-implicit-...
  kbuild: clean up scripts/gcc-version.sh
  kbuild: remove cc-version macro
  kbuild: update comment block of scripts/clang-version.sh
  kbuild: remove commented-out INITRD_COMPRESS
  kbuild: move -gsplit-dwarf, -gdwarf-4 option tests to Kconfig
  kbuild: [bin]deb-pkg: add DPKG_FLAGS variable
  kbuild: move ".config not found!" message from Kconfig to Makefile
  kbuild: invoke syncconfig if include/config/auto.conf.cmd is missing
  kbuild: simplify single target rules
  kbuild: remove empty rules for makefiles
  kbuild: make -r/-R effective in top Makefile for old Make versions
  kbuild: move tools_silent to a more relevant place
  kbuild: compute false-positive -Wmaybe-uninitialized cases in Kconfig
  kbuild: refactor cc-cross-prefix implementation
  kbuild: hardcode genksyms path and remove GENKSYMS variable
  scripts/gdb: refactor rules for symlink creation
  kbuild: create symlink to vmlinux-gdb.py in scripts_gdb target
  scripts/gdb: do not descend into scripts/gdb from scripts
  ...

1 files changed, 19 insertions, 23 deletions

diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 12b88d09c3a4..c0abd9a779c3 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -137,14 +137,14 @@ _c_flags += $(if $(patsubst n%,, \
 	$(CFLAGS_KCOV))
 endif
 
-# If building the kernel in a separate objtree expand all occurrences
-# of -Idir to -I$(srctree)/dir except for absolute paths (starting with '/').
-
-ifeq ($(KBUILD_SRC),)
 __c_flags	= $(_c_flags)
 __a_flags	= $(_a_flags)
 __cpp_flags     = $(_cpp_flags)
-else
+
+# If building the kernel in a separate objtree expand all occurrences
+# of -Idir to -I$(srctree)/dir except for absolute paths (starting with '/').
+ifeq ($(KBUILD_EXTMOD),)
+ifneq ($(KBUILD_SRC),)
 
 # -I$(obj) locates generated .h files
 # $(call addtree,-I$(obj)) locates .h files in srctree, from generated .c files
@@ -155,6 +155,7 @@ __c_flags	= $(if $(obj),$(call addtree,-I$(src)) -I$(obj)) \
 __a_flags	= $(call flags,_a_flags)
 __cpp_flags     = $(call flags,_cpp_flags)
 endif
+endif
 
 c_flags        = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE)     \
 		 -include $(srctree)/include/linux/compiler_types.h       \
@@ -230,7 +231,7 @@ $(obj)/%: $(src)/%_shipped
 # ---------------------------------------------------------------------------
 
 quiet_cmd_ld = LD      $@
-cmd_ld = $(LD) $(ld_flags) $(filter-out FORCE,$^) -o $@
+      cmd_ld = $(LD) $(ld_flags) $(real-prereqs) -o $@
 
 # Objcopy
 # ---------------------------------------------------------------------------
@@ -242,7 +243,7 @@ cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
 # ---------------------------------------------------------------------------
 
 quiet_cmd_gzip = GZIP    $@
-      cmd_gzip = cat $(filter-out FORCE,$^) | gzip -n -f -9 > $@
+      cmd_gzip = cat $(real-prereqs) | gzip -n -f -9 > $@
 
 # DTC
 # ---------------------------------------------------------------------------
@@ -270,7 +271,7 @@ DTC_FLAGS += $(DTC_FLAGS_$(basetarget))
 # Generate an assembly file to wrap the output of the device tree compiler
 quiet_cmd_dt_S_dtb= DTB     $@
 cmd_dt_S_dtb=						\
-(							\
+{							\
 	echo '\#include <asm-generic/vmlinux.lds.h>'; 	\
 	echo '.section .dtb.init.rodata,"a"';		\
 	echo '.balign STRUCT_ALIGNMENT';		\
@@ -280,7 +281,7 @@ cmd_dt_S_dtb=						\
 	echo '__dtb_$(subst -,_,$(*F))_end:';		\
 	echo '.global __dtb_$(subst -,_,$(*F))_end';	\
 	echo '.balign STRUCT_ALIGNMENT'; 		\
-) > $@
+} > $@
 
 $(obj)/%.dtb.S: $(obj)/%.dtb FORCE
 	$(call if_changed,dt_S_dtb)
@@ -320,7 +321,7 @@ dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)
 # append the size as a 32-bit littleendian number as gzip does.
 size_append = printf $(shell						\
 dec_size=0;								\
-for F in $1; do								\
+for F in $(real-prereqs); do					\
 	fsize=$$($(CONFIG_SHELL) $(srctree)/scripts/file-size.sh $$F);	\
 	dec_size=$$(expr $$dec_size + $$fsize);				\
 done;									\
@@ -334,23 +335,20 @@ printf "%08x\n" $$dec_size |						\
 )
 
 quiet_cmd_bzip2 = BZIP2   $@
-cmd_bzip2 = (cat $(filter-out FORCE,$^) | \
-	bzip2 -9 && $(call size_append, $(filter-out FORCE,$^))) > $@
+      cmd_bzip2 = { cat $(real-prereqs) | bzip2 -9 && $(size_append); } > $@
 
 # Lzma
 # ---------------------------------------------------------------------------
 
 quiet_cmd_lzma = LZMA    $@
-cmd_lzma = (cat $(filter-out FORCE,$^) | \
-	lzma -9 && $(call size_append, $(filter-out FORCE,$^))) > $@
+      cmd_lzma = { cat $(real-prereqs) | lzma -9 && $(size_append); } > $@
 
 quiet_cmd_lzo = LZO     $@
-cmd_lzo = (cat $(filter-out FORCE,$^) | \
-	lzop -9 && $(call size_append, $(filter-out FORCE,$^))) > $@
+      cmd_lzo = { cat $(real-prereqs) | lzop -9 && $(size_append); } > $@
 
 quiet_cmd_lz4 = LZ4     $@
-cmd_lz4 = (cat $(filter-out FORCE,$^) | \
-	lz4c -l -c1 stdin stdout && $(call size_append, $(filter-out FORCE,$^))) > $@
+      cmd_lz4 = { cat $(real-prereqs) | lz4c -l -c1 stdin stdout && \
+                  $(size_append); } > $@
 
 # U-Boot mkimage
 # ---------------------------------------------------------------------------
@@ -392,13 +390,11 @@ quiet_cmd_uimage = UIMAGE  $@
 # big dictionary would increase the memory usage too much in the multi-call
 # decompression mode. A BCJ filter isn't used either.
 quiet_cmd_xzkern = XZKERN  $@
-cmd_xzkern = (cat $(filter-out FORCE,$^) | \
-	sh $(srctree)/scripts/xz_wrap.sh && \
-	$(call size_append, $(filter-out FORCE,$^))) > $@
+      cmd_xzkern = { cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh && \
+                     $(size_append); } > $@
 
 quiet_cmd_xzmisc = XZMISC  $@
-cmd_xzmisc = (cat $(filter-out FORCE,$^) | \
-	xz --check=crc32 --lzma2=dict=1MiB) > $@
+      cmd_xzmisc = cat $(real-prereqs) | xz --check=crc32 --lzma2=dict=1MiB > $@
 
 # ASM offsets
 # ---------------------------------------------------------------------------