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-)

4 files changed, 30 insertions, 70 deletions

diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index 122f95c95869..8a9a4e1c7eab 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -215,11 +215,13 @@ else
 arg-check = $(if $(strip $(cmd_$@)),,1)
 endif
 
-# >'< substitution is for echo to work,
-# >$< substitution to preserve $ when reloading .cmd file
-# note: when using inline perl scripts [perl -e '...$$t=1;...']
-# in $(cmd_xxx) double $$ your perl vars
-make-cmd = $(subst \\,\\\\,$(subst \#,\\\#,$(subst $$,$$$$,$(call escsq,$(cmd_$(1))))))
+# Replace >$< with >$$< to preserve $ when reloading the .cmd file
+# (needed for make)
+# Replace >#< with >\#< to avoid starting a comment in the .cmd file
+# (needed for make)
+# Replace >'< with >'\''< to be able to enclose the whole string in '...'
+# (needed for the shell)
+make-cmd = $(call escsq,$(subst \#,\\\#,$(subst $$,$$$$,$(cmd_$(1)))))
 
 # Find any prerequisites that is newer than target or that does not exist.
 # PHONY targets skipped in both cases.
@@ -230,7 +232,7 @@ any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
 if_changed = $(if $(strip $(any-prereq) $(arg-check)),                       \
         @set -e;                                                             \
         $(echo-cmd) $(cmd_$(1));                                             \
-        echo 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd)
+        printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd)
 
 # Execute the command and also postprocess generated .d dependencies file.
 if_changed_dep = $(if $(strip $(any-prereq) $(arg-check) ),                  \
diff --git a/scripts/Makefile.clean b/scripts/Makefile.clean
index 686cb0d31c7c..a651cee84f2a 100644
--- a/scripts/Makefile.clean
+++ b/scripts/Makefile.clean
@@ -40,8 +40,8 @@ subdir-ymn	:= $(addprefix $(obj)/,$(subdir-ymn))
 # build a list of files to remove, usually relative to the current
 # directory
 
-__clean-files   := $(extra-y) $(always)                  \
-                   $(targets) $(clean-files)             \
+__clean-files   := $(extra-y) $(extra-m) $(extra-)       \
+                   $(always) $(targets) $(clean-files)   \
                    $(host-progs)                         \
                    $(hostprogs-y) $(hostprogs-m) $(hostprogs-)
 
diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn
index 65643506c71c..f734033af219 100644
--- a/scripts/Makefile.extrawarn
+++ b/scripts/Makefile.extrawarn
@@ -26,16 +26,6 @@ warning-1 += $(call cc-option, -Wmissing-include-dirs)
 warning-1 += $(call cc-option, -Wunused-but-set-variable)
 warning-1 += $(call cc-disable-warning, missing-field-initializers)
 
-# Clang
-warning-1 += $(call cc-disable-warning, initializer-overrides)
-warning-1 += $(call cc-disable-warning, unused-value)
-warning-1 += $(call cc-disable-warning, format)
-warning-1 += $(call cc-disable-warning, unknown-warning-option)
-warning-1 += $(call cc-disable-warning, sign-compare)
-warning-1 += $(call cc-disable-warning, format-zero-length)
-warning-1 += $(call cc-disable-warning, uninitialized)
-warning-1 += $(call cc-option, -fcatch-undefined-behavior)
-
 warning-2 := -Waggregate-return
 warning-2 += -Wcast-align
 warning-2 += -Wdisabled-optimization
@@ -64,4 +54,15 @@ ifeq ("$(strip $(warning))","")
 endif
 
 KBUILD_CFLAGS += $(warning)
+else
+
+ifeq ($(COMPILER),clang)
+KBUILD_CFLAGS += $(call cc-disable-warning, initializer-overrides)
+KBUILD_CFLAGS += $(call cc-disable-warning, unused-value)
+KBUILD_CFLAGS += $(call cc-disable-warning, format)
+KBUILD_CFLAGS += $(call cc-disable-warning, unknown-warning-option)
+KBUILD_CFLAGS += $(call cc-disable-warning, sign-compare)
+KBUILD_CFLAGS += $(call cc-disable-warning, format-zero-length)
+KBUILD_CFLAGS += $(call cc-disable-warning, uninitialized)
+endif
 endif
diff --git a/scripts/Makefile.host b/scripts/Makefile.host
index 66893643fd7d..ab5980f91714 100644
--- a/scripts/Makefile.host
+++ b/scripts/Makefile.host
@@ -20,21 +20,12 @@
 # Will compile qconf as a C++ program, and menu as a C program.
 # They are linked as C++ code to the executable qconf
 
-# hostprogs-y := conf
-# conf-objs  := conf.o libkconfig.so
-# libkconfig-objs := expr.o type.o
-# Will create a shared library named libkconfig.so that consists of
-# expr.o and type.o (they are both compiled as C code and the object files
-# are made as position independent code).
-# conf.c is compiled as a C program, and conf.o is linked together with
-# libkconfig.so as the executable conf.
-# Note: Shared libraries consisting of C++ files are not supported
-
 __hostprogs := $(sort $(hostprogs-y) $(hostprogs-m))
 
 # C code
 # Executables compiled from a single .c file
-host-csingle    := $(foreach m,$(__hostprogs),$(if $($(m)-objs),,$(m)))
+host-csingle    := $(foreach m,$(__hostprogs), \
+                        $(if $($(m)-objs)$($(m)-cxxobjs),,$(m)))
 
 # C executables linked based on several .o files
 host-cmulti     := $(foreach m,$(__hostprogs),\
@@ -44,33 +35,17 @@ host-cmulti	:= $(foreach m,$(__hostprogs),\
 host-cobjs      := $(sort $(foreach m,$(__hostprogs),$($(m)-objs)))
 
 # C++ code
-# C++ executables compiled from at least on .cc file
+# C++ executables compiled from at least one .cc file
 # and zero or more .c files
 host-cxxmulti   := $(foreach m,$(__hostprogs),$(if $($(m)-cxxobjs),$(m)))
 
 # C++ Object (.o) files compiled from .cc files
 host-cxxobjs    := $(sort $(foreach m,$(host-cxxmulti),$($(m)-cxxobjs)))
 
-# Shared libaries (only .c supported)
-# Shared libraries (.so) - all .so files referenced in "xxx-objs"
-host-cshlib     := $(sort $(filter %.so, $(host-cobjs)))
-# Remove .so files from "xxx-objs"
-host-cobjs      := $(filter-out %.so,$(host-cobjs))
-
-#Object (.o) files used by the shared libaries
-host-cshobjs    := $(sort $(foreach m,$(host-cshlib),$($(m:.so=-objs))))
-
 # output directory for programs/.o files
-# hostprogs-y := tools/build may have been specified. Retrieve directory
-host-objdirs := $(foreach f,$(__hostprogs), $(if $(dir $(f)),$(dir $(f))))
-# directory of .o files from prog-objs notation
-host-objdirs += $(foreach f,$(host-cmulti),                  \
-                    $(foreach m,$($(f)-objs),                \
-                        $(if $(dir $(m)),$(dir $(m)))))
-# directory of .o files from prog-cxxobjs notation
-host-objdirs += $(foreach f,$(host-cxxmulti),                  \
-                    $(foreach m,$($(f)-cxxobjs),                \
-                        $(if $(dir $(m)),$(dir $(m)))))
+# hostprogs-y := tools/build may have been specified.
+# Retrieve also directory of .o files from prog-objs or prog-cxxobjs notation
+host-objdirs := $(dir $(__hostprogs) $(host-cobjs) $(host-cxxobjs))
 
 host-objdirs := $(strip $(sort $(filter-out ./,$(host-objdirs))))
 
@@ -81,8 +56,6 @@ host-cmulti	:= $(addprefix $(obj)/,$(host-cmulti))
 host-cobjs      := $(addprefix $(obj)/,$(host-cobjs))
 host-cxxmulti   := $(addprefix $(obj)/,$(host-cxxmulti))
 host-cxxobjs    := $(addprefix $(obj)/,$(host-cxxobjs))
-host-cshlib     := $(addprefix $(obj)/,$(host-cshlib))
-host-cshobjs    := $(addprefix $(obj)/,$(host-cshobjs))
 host-objdirs    := $(addprefix $(obj)/,$(host-objdirs))
 
 obj-dirs += $(host-objdirs)
@@ -123,7 +96,7 @@ quiet_cmd_host-cmulti	= HOSTLD  $@
       cmd_host-cmulti   = $(HOSTCC) $(HOSTLDFLAGS) -o $@ \
                           $(addprefix $(obj)/,$($(@F)-objs)) \
                           $(HOST_LOADLIBES) $(HOSTLOADLIBES_$(@F))
-$(host-cmulti): $(obj)/%: $(host-cobjs) $(host-cshlib) FORCE
+$(host-cmulti): $(obj)/%: $(host-cobjs) FORCE
         $(call if_changed,host-cmulti)
 
 # Create .o file from a single .c file
@@ -140,7 +113,7 @@ quiet_cmd_host-cxxmulti	= HOSTLD  $@
                           $(foreach o,objs cxxobjs,\
                           $(addprefix $(obj)/,$($(@F)-$(o)))) \
                           $(HOST_LOADLIBES) $(HOSTLOADLIBES_$(@F))
-$(host-cxxmulti): $(obj)/%: $(host-cobjs) $(host-cxxobjs) $(host-cshlib) FORCE
+$(host-cxxmulti): $(obj)/%: $(host-cobjs) $(host-cxxobjs) FORCE
         $(call if_changed,host-cxxmulti)
 
 # Create .o file from a single .cc (C++) file
@@ -149,21 +122,5 @@ quiet_cmd_host-cxxobjs	= HOSTCXX $@
 $(host-cxxobjs): $(obj)/%.o: $(src)/%.cc FORCE
         $(call if_changed_dep,host-cxxobjs)
 
-# Compile .c file, create position independent .o file
-# host-cshobjs -> .o
-quiet_cmd_host-cshobjs  = HOSTCC  -fPIC $@
-      cmd_host-cshobjs  = $(HOSTCC) $(hostc_flags) -fPIC -c -o $@ $<
-$(host-cshobjs): $(obj)/%.o: $(src)/%.c FORCE
-        $(call if_changed_dep,host-cshobjs)
-
-# Link a shared library, based on position independent .o files
-# *.o -> .so shared library (host-cshlib)
-quiet_cmd_host-cshlib   = HOSTLLD -shared $@
-      cmd_host-cshlib   = $(HOSTCC) $(HOSTLDFLAGS) -shared -o $@ \
-                          $(addprefix $(obj)/,$($(@F:.so=-objs))) \
-                          $(HOST_LOADLIBES) $(HOSTLOADLIBES_$(@F))
-$(host-cshlib): $(obj)/%: $(host-cshobjs) FORCE
-        $(call if_changed,host-cshlib)
-
 targets += $(host-csingle)  $(host-cmulti) $(host-cobjs)\
-           $(host-cxxmulti) $(host-cxxobjs) $(host-cshlib) $(host-cshobjs)
+           $(host-cxxmulti) $(host-cxxobjs)