Use 'git describe' for working builds

When building from an arbitrary commit in the git tree it's useful
for the resulting packages to be uniquely identifiable.  Therefore,
the build system has been updated to detect if your compiling in
git tree.

If you are building in a git tree, and there are commits after the
last annotated tag.  Then the <id>-<hash> component of 'git describe'
will be used to overwrite the 'Release:' field in the META file.

The only tricky part is that to ensure the 'make dist' tarball is
built using the correct release.  A dist-hook was added to the top
level make file to rewrite the META file using the correct release.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #195
Issue #111

diff --git a/Makefile.am b/Makefile.am
index 232c305239d11393d8578516b47747efbfd6fa41..cea9db97b153b67a16445b9d2f8f4fbdf2ad05f6 100644 (file)
--- a/Makefile.am
+++ b/Makefile.am
@@ -32,6 +32,10 @@ distclean-local::
                -o -name '*.order' -o -name '*.markers' \) \
                -type f -print | xargs $(RM)
 
+dist-hook:
+       sed -i 's/Release:[[:print:]]*/Release:      $(RELEASE)/' \
+               $(distdir)/META
+
 ctags:
        $(RM) $(top_srcdir)/tags
        find $(top_srcdir) -name .git -prune -o -name '*.[hc]' | xargs ctags

diff --git a/config/spl-meta.m4 b/config/spl-meta.m4
index af8be801a94e2d27580a0644634eee7de7719c8e..28103bc103aa7a3dcdc2781e783257a4c7ca3c59 100644 (file)
--- a/config/spl-meta.m4
+++ b/config/spl-meta.m4
@@ -2,16 +2,20 @@
 # Written by Chris Dunlap <cdunlap@llnl.gov>.
 # Modified by Brian Behlendorf <behlendorf1@llnl.gov>.
 ###############################################################################
-# SPL_AC_META: Read metadata from the META file.
+# SPL_AC_META: Read metadata from the META file.  When building from a
+# git repository the SPL_META_RELEASE field will be overwritten if there
+# is an annotated tag matching the form SPL_META_NAME-SPL_META_VERSION-*.
+# This allows for working builds to be uniquely identified using the git
+# commit hash.
 ###############################################################################
 
 AC_DEFUN([SPL_AC_META], [
        AC_MSG_CHECKING([metadata])
 
        META="$srcdir/META"
-       _spl_ac_meta_got_file=no
+       _spl_ac_meta_type="none"
        if test -f "$META"; then
-               _spl_ac_meta_got_file=yes
+               _spl_ac_meta_type="META file"
 
                SPL_META_NAME=_SPL_AC_META_GETVAL([(?:NAME|PROJECT|PACKAGE)]);
                if test -n "$SPL_META_NAME"; then
@@ -30,6 +34,16 @@ AC_DEFUN([SPL_AC_META], [
                fi
 
                SPL_META_RELEASE=_SPL_AC_META_GETVAL([RELEASE]);
+               if git rev-parse --git-dir > /dev/null 2>&1; then
+                       _match="${SPL_META_NAME}-${SPL_META_VERSION}*"
+                       _alias=$(git describe --match=${_match} 2>/dev/null)
+                       _release=$(echo ${_alias}|cut -f3- -d'-'|sed 's/-/_/g')
+                       if test -n "${_release}"; then
+                               SPL_META_RELEASE=${_release}
+                               _spl_ac_meta_type="git describe"
+                       fi
+               fi
+
                if test -n "$SPL_META_RELEASE"; then
                        AC_DEFINE_UNQUOTED([SPL_META_RELEASE], ["$SPL_META_RELEASE"],
                                [Define the project release.]
@@ -97,7 +111,7 @@ AC_DEFUN([SPL_AC_META], [
                fi
        fi
 
-       AC_MSG_RESULT([$_spl_ac_meta_got_file])
+       AC_MSG_RESULT([$_spl_ac_meta_type])
        ]
 )