Re: [PATCH, v2] kbuild: Improve version string logic

David Rientjes
2009-10-15T08:02:58Z

On Wed, 14 Oct 2009, David Rientjes wrote:

> We could easily go with my suggestion of allowing "make LOCALVERSION=" to
> override all additions to the kernel version when CONFIG_LOCALVERSION_AUTO
> is disabled. For such configurations, kernels would be built with this
> variable to specify how it's different from the vanilla version and would
> suppress the `+'.
>

The following patch implements this suggestion and folds both of my
proposed patches together.

kbuild: improve version string logic

The LOCALVERSION= string passed to "make" will now always be appended to
the kernel version after CONFIG_LOCALVERSION, if it exists, regardless of
whether CONFIG_LOCALVERSION_AUTO is set or not. This allows users to
uniquely identify their kernel builds with a string.

scripts/setlocalversion will now always be called to determine whether
the repository is beyond a tagged (release) commit. When at a tagged
commit, this script will now suppress all output.

If CONFIG_LOCALVERSION_AUTO is enabled, the unique SCM tag reported by
setlocalversion (or .scmversion) is appended to the kernel version, if it
exists. When CONFIG_LOCALVERSION_AUTO is not enabled, a `+' is appended
to the kernel version to represent that the kernel has been revised since
the last release unless "make LOCALVERSION=" was used to uniquely identify
the build.

The end result is this:

- when LOCALVERSION= is passed to "make", it is appended to the kernel
version,

- when CONFIG_LOCALVERSION_AUTO is enabled, a unique SCM identifier is
appended if the respository has been revised beyond a tagged commit,
and

- when CONFIG_LOCALVERSION_AUTO is disabled, a `+' is appended if the
repository has been revised beyond a tagged commit and LOCALVERSION=
was not passed to "make".

Examples:

With CONFIG_LOCALVERSION_AUTO: "make" results in
v2.6.32-rc4-00149-ga3ccf63. If there are uncommited changes to the
respository, it results in v2.6.32-rc4-00149-ga3ccf63-dirty. If
"make LOCALVERSION=kbuild" were used, it results in
v2.6.32-rc4-kbuild-00149-ga3ccf63-dirty.

Without CONFIG_LOCALVERSION_AUTO, "make" results in v2.6.32-rc4+
unless the repository is at the Linux v2.6.32-rc4 commit (in which
case the version would be v2.6.32-rc4). If "make LOCALVERSION=kbuild"
were used, it results in v2.6.32-rc4-kbuild.

Also renames variables such as localver-auto and _localver-auto to more
accurately describe what they represent: localver-extra and
scm-identifier, respectively.

Signed-off-by: David Rientjes <rientjes@google.com>
---
Makefile | 43 +++++++++++++++++++++++++++----------------
scripts/setlocalversion | 3 ++-
2 files changed, 29 insertions(+), 17 deletions(-)

diff --git a/Makefile b/Makefile
--- a/Makefile
+++ b/Makefile
@@ -898,14 +898,19 @@ $(vmlinux-dirs): prepare scripts
# $(localver)
# localversion* (files without backups, containing '~')
# $(CONFIG_LOCALVERSION) (from kernel config setting)
-# $(localver-auto) (only if CONFIG_LOCALVERSION_AUTO is set)
-# ./scripts/setlocalversion (SCM tag, if one exists)
-# $(LOCALVERSION) (from make command line if provided)
+# $(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)
#
-# Note how the final $(localver-auto) string is included *only* if the
-# kernel config option CONFIG_LOCALVERSION_AUTO is selected. Also, at the
-# moment, only git is supported but other SCMs can edit the script
-# scripts/setlocalversion and add the appropriate checks as needed.
+# 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 \
@@ -914,26 +919,32 @@ string = $(shell cat /dev/null \
localver = $(subst $(space),, $(string) \
$(patsubst "%",%,$(CONFIG_LOCALVERSION)))

-# If CONFIG_LOCALVERSION_AUTO is set scripts/setlocalversion is called
-# and if the SCM is know a tag from the SCM is appended.
-# The appended tag is determined by the SCM used.
+# 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
-ifdef CONFIG_LOCALVERSION_AUTO
-
ifeq ($(wildcard .scmversion),)
- _localver-auto = $(shell $(CONFIG_SHELL) \
+ scm-identifier = $(shell $(CONFIG_SHELL) \
$(srctree)/scripts/setlocalversion $(srctree))
else
- _localver-auto = $(shell cat .scmversion 2> /dev/null)
+ scm-identifier = $(shell cat .scmversion 2> /dev/null)
endif

- localver-auto = $(LOCALVERSION)$(_localver-auto)
+ifdef CONFIG_LOCALVERSION_AUTO
+ localver-extra = $(scm-identifier)
+else
+ ifneq ($scm-identifier,)
+ ifeq ($(LOCALVERSION),)
+ localver-extra = +
+ endif
+ endif
endif

-localver-full = $(localver)$(localver-auto)
+localver-full = $(localver)$(LOCALVERSION)$(localver-extra)

# Store (new) KERNELRELASE string in include/config/kernel.release
kernelrelease = $(KERNELVERSION)$(localver-full)
diff --git a/scripts/setlocalversion b/scripts/setlocalversion
--- a/scripts/setlocalversion
+++ b/scripts/setlocalversion
@@ -26,7 +26,8 @@ if head=`git rev-parse --verify --short HEAD 2>/dev/null`; then
# If we are past a tagged commit (like "v2.6.30-rc5-302-g72357d5"),
# we pretty print it.
if atag="`git describe 2>/dev/null`"; then
- echo "$atag" | awk -F- '{printf("-%05d-%s", $(NF-1),$(NF))}'
+ echo "$atag" | awk -F- 'int($(NF-1)) > 0 \
+ {printf("-%05d-%s", $(NF-1),$(NF))}'

# If we don't have a tag at all we print -g{commitish}.
else