convert the contents of make_dot_patch into a function and put it in GitUtils

1 files changed, 60 insertions, 0 deletions

diff --git a/Porting/GitUtils.pm b/Porting/GitUtils.pm
new file mode 100755
index 0000000000..7abfe917d3
--- /dev/null
+++ b/Porting/GitUtils.pm
@@ -0,0 +1,60 @@
+#!/usr/bin/perl
+use strict;
+use warnings;
+use POSIX qw(strftime);
+
+use base qw/Exporter/;
+our @EXPORT_OK=qw(iso_time_with_dot gen_dot_patch);
+
+sub iso_time_with_dot {
+    strftime "%Y-%m-%d.%H:%M:%S",gmtime(shift||time)
+}
+
+# generate the contents of a .patch file for an arbitrary commitish, or for HEAD if none is supplied
+# assumes the CWD is inside of a perl git repository. If the repository is bare then refs/heads/*
+# is used to determine the branch. If the repository is not bare then refs/remotes/origin/* is used
+# to determine the branch. (The assumption being that if its bare then this is running inside of
+# the master git repo - if its not bare then it is a checkout which may not have all the branches)
+sub gen_dot_patch {
+    my $target= shift || 'HEAD';
+    chomp(my ($git_dir, $is_bare, $sha1)=`git rev-parse --git-dir --is-bare-repository $target`);
+    die "Not in a git repository!" if !$git_dir;
+    $is_bare= "" if $is_bare and $is_bare eq 'false';
+
+    # which branches to scan - the order here is important, the first hit we find we use
+    # so if two branches can both reach a ref we want the right one first.
+    my @branches=(
+              'blead',
+              'maint-5.10',
+              'maint-5.8',
+              'maint-5.8-dor',
+              'maint-5.6',
+              'maint-5.005',
+              'maint-5.004',
+              # and more generalized searches...
+              'refs/heads/*',
+              'refs/remotes/*',
+              'refs/*',
+    );
+    my $reftype= $is_bare ? "heads" : "remotes/origin";
+    my $branch;
+    foreach my $name (@branches) {
+        my $refs= $name=~m!^refs/! ? $name : "refs/$reftype/$name";
+        my $cmd= "git name-rev --name-only --refs=$refs $sha1";
+        chomp($branch= `$cmd`);
+        last if $branch ne 'undefined';
+    }
+    for ($branch) {
+        $_  ||= "error";            # hmm, we didnt get /anything/ from name-rev?
+        s!^\Q$reftype\E/!! ||       # strip off the reftype
+        s!^refs/heads/!!   ||       # possible other places it was found
+        s!^refs/remotes/!! ||       # ...
+        s!^refs/!!;                 # might even be a tag or something weirdo...
+        s![~^].*\z!!;               # strip off how far we are from the item
+    }
+    my $tstamp= iso_time_with_dot(`git log -1 --pretty="format:%ct" $sha1`);
+    chomp(my $describe= `git describe`);
+    join(" ", $branch, $tstamp, $sha1, $describe);
+}
+
+1;