Add git based versioning.

Add git_version.sh, which gathers the following information:
* wether git is used.
* what SHA-ID the latest commit has.
* the name of the branch we're in.
* whether there are local changes.
This information is piped to git_version.h, which is included in
src/via_driver.c to print extra version information in VIAProbe.

This is not a foolproof solution as the file doesn't get rebuilt all the time,
only when it's not present, like after make clean.

1 files changed, 60 insertions, 0 deletions

diff --git a/git_version.sh b/git_version.sh
new file mode 100755
index 0000000..ea597e6
--- /dev/null
+++ b/git_version.sh
@@ -0,0 +1,60 @@
+#! /bin/sh
+#
+# Generate some basic versioning information which can be piped to a header.
+#
+echo "/*"
+echo " * Basic versioning gathered from the git repository."
+echo " */"
+echo ""
+# this might not correspond with the final filename, but will be close enough.
+echo "#ifndef HAVE_GIT_VERSION_H"
+echo "#define HAVE_GIT_VERSION_H 1"
+echo ""
+
+git_tools=`which git-whatchanged`
+if test "$git_tools" != ""; then
+    if [ -e .git/index ]; then
+        echo "/* This is a git repository */"
+        echo "#define GIT_USED 1"
+        echo ""
+
+        # SHA-ID
+        git_shaid=`git-whatchanged | head -n1 | sed s/^diff-tree\ // | sed s/\ \(from\ \[0-9a-f\]*\.\.\.\)$//`
+        echo "/* Git SHA ID of last commit */"
+        echo "#define GIT_SHAID \"$git_shaid\""
+        echo ""
+
+        # Branch -- use git-status instead of git-branch
+        git_branch=`git-status | grep "# On branch" | sed s/#\ On\ branch\ //`
+        if test "$git_branch" = ""; then
+            git_branch="master"
+        fi
+        echo "/* Branch this tree is on */"
+        echo "#define GIT_BRANCH \"$git_branch\""
+        echo ""
+
+        # Any uncommitted changes we should know about?
+        git_uncommitted=`git-status | grep "Changed but not updated"`
+        if test "$git_uncommitted" = ""; then
+            git_uncommitted=`git-status | grep "Updated but not checked in"`
+        fi
+
+        if test "$git_uncommitted" != ""; then
+            echo "/* Local changes might be breaking things */"
+            echo "#define GIT_UNCOMMITTED 1"
+        else
+            echo "/* SHA-ID uniquely defines the state of this code */"
+            echo "#undef GIT_UNCOMMITTED"
+        fi
+    else
+        echo "/* This is not a git repository */"
+        echo "#undef GIT_USED"
+    fi
+else
+    echo "/* git is not installed */"
+    echo "#undef GIT_USED"
+fi
+
+echo ""
+echo "#endif /* HAVE_GIT_VERSION_H */"
+