From a5a658ab48f7dfa7fd134e505ef23304eaa0ce54 Mon Sep 17 00:00:00 2001
From: Jason Evans <je@fb.com>
Date: Tue, 2 Sep 2014 15:07:07 -0700
Subject: [PATCH] Make VERSION generation more robust.

Relax the "are we in a git repo?" check to succeed even if the top level
jemalloc directory is not at the top level of the git repo.

Add git tag filtering so that only version triplets match when
generating VERSION.

Add fallback bogus VERSION creation, so that in the worst case, rather
than generating empty values for e.g. JEMALLOC_VERSION_MAJOR,
configuration ends up generating useless constants.
---
 configure.ac | 30 ++++++++++++++++++++++++++----
 1 file changed, 26 insertions(+), 4 deletions(-)

diff --git a/configure.ac b/configure.ac
index 6f8fd3fd..3b658852 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1029,11 +1029,33 @@ dnl ============================================================================
 dnl jemalloc configuration.
 dnl 
 
-dnl Set VERSION if source directory has an embedded git repository or is a git submodule.
-if test -e "${srcroot}.git" ; then
-  git describe --long --abbrev=40 > ${srcroot}VERSION
+dnl Set VERSION if source directory is inside a git repository.
+if test "x`git rev-parse --is-inside-work-tree 2>/dev/null`" = "xtrue" ; then
+  dnl Pattern globs aren't powerful enough to match both single- and
+  dnl double-digit version numbers, so iterate over patterns to support up to
+  dnl version 99.99.99 without any accidental matches.
+  rm -f "${srcroot}VERSION"
+  for pattern in ['[0-9].[0-9].[0-9]' '[0-9].[0-9].[0-9][0-9]' \
+                 '[0-9].[0-9][0-9].[0-9]' '[0-9].[0-9][0-9].[0-9][0-9]' \
+                 '[0-9][0-9].[0-9].[0-9]' '[0-9][0-9].[0-9].[0-9][0-9]' \
+                 '[0-9][0-9].[0-9][0-9].[0-9]' \
+                 '[0-9][0-9].[0-9][0-9].[0-9][0-9]']; do
+    if test ! -e "${srcroot}VERSION" ; then
+      git describe --long --abbrev=40 --match="${pattern}" > "${srcroot}VERSION.tmp" 2>/dev/null
+      if test $? -eq 0 ; then
+        mv "${srcroot}VERSION.tmp" "${srcroot}VERSION"
+        break
+      fi
+    fi
+  done
 fi
-jemalloc_version=`cat ${srcroot}VERSION`
+rm -f "${srcroot}VERSION.tmp"
+if test ! -e "${srcroot}VERSION" ; then
+  AC_MSG_RESULT(
+    [Missing VERSION file, and unable to generate it; creating bogus VERSION])
+  echo "0.0.0-0-g0000000000000000000000000000000000000000" > "${srcroot}VERSION"
+fi
+jemalloc_version=`cat "${srcroot}VERSION"`
 jemalloc_version_major=`echo ${jemalloc_version} | tr ".g-" " " | awk '{print [$]1}'`
 jemalloc_version_minor=`echo ${jemalloc_version} | tr ".g-" " " | awk '{print [$]2}'`
 jemalloc_version_bugfix=`echo ${jemalloc_version} | tr ".g-" " " | awk '{print [$]3}'`