Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild

Pull kbuild updates from Michal Marek:
 - make clean also considers $(extra-m) and $(extra-) to be consistent
 - cleanup and fixes in scripts/Makefile.host
 - allow to override the name of the Python 2 executable with make
   PYTHON=... (only needed for ia64 in practice)
 - option to split debugingo into *.dwo files to save disk space if the
   compiler supports it (CONFIG_DEBUG_INFO_SPLIT)
 - option to use dwarf4 debuginfo if the compiler supports it
   (CONFIG_DEBUG_INFO_DWARF4)
 - fix for disabling certain warnings with clang
 - fix for unneeded rebuild with dash when a command contains
   backslashes

* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  kbuild: Fix handling of backslashes in *.cmd files
  kbuild, LLVMLinux: Supress warnings unless W=1-3
  Kbuild: Add a option to enable dwarf4 v2
  kbuild: Support split debug info v4
  kbuild: allow to override Python command name
  kbuild: clean-up and bug fix of scripts/Makefile.host
  kbuild: clean up scripts/Makefile.host
  kbuild: drop shared library support from Makefile.host
  kbuild: fix a bug of C++ host program handling
  kbuild: fix a typo in scripts/Makefile.host
  scripts/Makefile.clean: clean also $(extra-m) and $(extra-)

1 files changed, 11 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index a897c50db515..ada00f0d2a11 100644
--- a/Makefile
+++ b/Makefile
@@ -372,6 +372,7 @@ GENKSYMS	= scripts/genksyms/genksyms
 INSTALLKERNEL  := installkernel
 DEPMOD          = /sbin/depmod
 PERL            = perl
+PYTHON          = python
 CHECK           = sparse
 
 CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
@@ -422,7 +423,7 @@ KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(S
 export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
 export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC
 export CPP AR NM STRIP OBJCOPY OBJDUMP
-export MAKE AWK GENKSYMS INSTALLKERNEL PERL UTS_MACHINE
+export MAKE AWK GENKSYMS INSTALLKERNEL PERL PYTHON UTS_MACHINE
 export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
 
 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS
@@ -687,6 +688,7 @@ KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
 # source of a reference will be _MergedGlobals and not on of the whitelisted names.
 # See modpost pattern 2
 KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)
+KBUILD_CFLAGS += $(call cc-option, -fcatch-undefined-behavior)
 else
 
 # This warning generated too much noise in a regular build.
@@ -710,9 +712,16 @@ endif
 KBUILD_CFLAGS   += $(call cc-option, -fno-var-tracking-assignments)
 
 ifdef CONFIG_DEBUG_INFO
+ifdef CONFIG_DEBUG_INFO_SPLIT
+KBUILD_CFLAGS   += $(call cc-option, -gsplit-dwarf, -g)
+else
 KBUILD_CFLAGS   += -g
+endif
 KBUILD_AFLAGS   += -Wa,-gdwarf-2
 endif
+ifdef CONFIG_DEBUG_INFO_DWARF4
+KBUILD_CFLAGS   += $(call cc-option, -gdwarf-4,)
+endif
 
 ifdef CONFIG_DEBUG_INFO_REDUCED
 KBUILD_CFLAGS   += $(call cc-option, -femit-struct-debug-baseonly) \
@@ -1398,6 +1407,7 @@ clean: $(clean-dirs)
         @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
                 \( -name '*.[oas]' -o -name '*.ko' -o -name '.*.cmd' \
                 -o -name '*.ko.*' \
+                -o -name '*.dwo'  \
                 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
                 -o -name '*.symtypes' -o -name 'modules.order' \
                 -o -name modules.builtin -o -name '.tmp_*.o.*' \