kbuild: Clean up and speed up the localversion logic

Now that we run scripts/setlocalversion during every build, it makes
sense to move all the localversion logic there. This cleans up the
toplevel Makefile and also makes sure that the script is called only
once in 'make prepare' (previously, it would be called every time due to
a variable expansion in an ifneq statement). No user-visible change is
intended, unless one runs the setlocalversion script directly.

Reported-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Nico Schottelius <nico-linuxsetlocalversion@schottelius.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>

1 files changed, 3 insertions, 71 deletions

diff --git a/Makefile b/Makefile
index ea5f0bee1934..a86ac8c4798e 100644
--- a/Makefile
+++ b/Makefile
@@ -883,80 +883,12 @@ PHONY += $(vmlinux-dirs)
 $(vmlinux-dirs): prepare scripts
         $(Q)$(MAKE) $(build)=$@
 
-# Build the kernel release string
-#
-# The KERNELRELEASE value built here is stored in the file
-# include/config/kernel.release, and is used when executing several
-# make targets, such as "make install" or "make modules_install."
-#
-# The eventual kernel release string consists of the following fields,
-# shown in a hierarchical format to show how smaller parts are concatenated
-# to form the larger and final value, with values coming from places like
-# the Makefile, kernel config options, make command line options and/or
-# SCM tag information.
-#
-#       $(KERNELVERSION)
-#         $(VERSION)                    eg, 2
-#         $(PATCHLEVEL)                 eg, 6
-#         $(SUBLEVEL)                   eg, 18
-#         $(EXTRAVERSION)               eg, -rc6
-#       $(localver-full)
-#         $(localver)
-#           localversion*               (files without backups, containing '~')
-#           $(CONFIG_LOCALVERSION)      (from kernel config setting)
-#         $(LOCALVERSION)               (from make command line, if provided)
-#         $(localver-extra)
-#           $(scm-identifier)           (unique SCM tag, if one exists)
-#             ./scripts/setlocalversion (only with CONFIG_LOCALVERSION_AUTO)
-#             .scmversion               (only with CONFIG_LOCALVERSION_AUTO)
-#           +                           (only without CONFIG_LOCALVERSION_AUTO
-#                                        and without LOCALVERSION= and
-#                                        repository is at non-tagged commit)
-#
-# For kernels without CONFIG_LOCALVERSION_AUTO compiled from an SCM that has
-# been revised beyond a tagged commit, `+' is appended to the version string
-# when not overridden by using "make LOCALVERSION=".  This indicates that the
-# kernel is not a vanilla release version and has been modified.
-
-pattern = ".*/localversion[^~]*"
-string  = $(shell cat /dev/null \
-           `find $(objtree) $(srctree) -maxdepth 1 -regex $(pattern) | sort -u`)
-
-localver = $(subst $(space),, $(string) \
-                              $(patsubst "%",%,$(CONFIG_LOCALVERSION)))
-
-# scripts/setlocalversion is called to create a unique identifier if the source
-# is managed by a known SCM and the repository has been revised since the last
-# tagged (release) commit.  The format of the identifier is determined by the
-# SCM's implementation.
-#
-# .scmversion is used when generating rpm packages so we do not loose
-# the version information from the SCM when we do the build of the kernel
-# from the copied source
-ifeq ($(wildcard .scmversion),)
-        scm-identifier = $(shell $(CONFIG_SHELL) \
-                         $(srctree)/scripts/setlocalversion $(srctree))
-else
-        scm-identifier = $(shell cat .scmversion 2> /dev/null)
-endif
-
-ifdef CONFIG_LOCALVERSION_AUTO
-        localver-extra = $(scm-identifier)
-else
-        ifneq ($(scm-identifier),)
-                ifeq ($(LOCALVERSION),)
-                        localver-extra = +
-                endif
-        endif
-endif
-
-localver-full = $(localver)$(LOCALVERSION)$(localver-extra)
-
 # Store (new) KERNELRELASE string in include/config/kernel.release
-kernelrelease = $(KERNELVERSION)$(localver-full)
+localversion = $(shell $(CONFIG_SHELL) \
+               $(srctree)/scripts/setlocalversion $(srctree))
 include/config/kernel.release: include/config/auto.conf FORCE
         $(Q)rm -f $@
-        $(Q)echo $(kernelrelease) > $@
+        $(Q)echo $(KERNELVERSION)$(localversion) > $@
 
 
 # Things we need to do before we recursively start building the kernel