checkpatch: enable GIT_DIR environment use to set git repository loca…

…tion

If set, use the environment variable GIT_DIR to change the default .git
location of the kernel git tree.

If GIT_DIR is unset, keep using the current ".git" default.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Joe Perches <[email protected]>
Tested-by: Geert Uytterhoeven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

scripts/checkpatch.pl

@@ -43,6 +43,8 @@
 my $fix = 0;
 my $fix_inplace = 0;
 my $root;
+my $gitroot = $ENV{'GIT_DIR'};
+$gitroot = ".git" if !defined($gitroot);
 my %debug;
 my %camelcase = ();
 my %use_type = ();
@@ -908,7 +910,7 @@ sub is_maintained_obsolete {
 sub is_SPDX_License_valid {
  my ($license) = @_;
 
- return 1 if (!$tree || which("python") eq "" || !(-e "$root/scripts/spdxcheck.py") || !(-e "$root/.git"));
+ return 1 if (!$tree || which("python") eq "" || !(-e "$root/scripts/spdxcheck.py") || !(-e "$gitroot"));
 
  my $root_path = abs_path($root);
  my $status = `cd "$root_path"; echo "$license" | python scripts/spdxcheck.py -`;
@@ -926,7 +928,7 @@ sub seed_camelcase_includes {
 
  $camelcase_seeded = 1;
 
- if (-e ".git") {
+ if (-e "$gitroot") {
  my $git_last_include_commit = `${git_command} log --no-merges --pretty=format:"%h%n" -1 -- include`;
  chomp $git_last_include_commit;
  $camelcase_cache = ".checkpatch-camelcase.git.$git_last_include_commit";
@@ -954,7 +956,7 @@ sub seed_camelcase_includes {
  return;
  }
 
- if (-e ".git") {
+ if (-e "$gitroot") {
  $files = `${git_command} ls-files "include/*.h"`;
  @include_files = split('\n', $files);
  }
@@ -987,7 +989,7 @@ sub git_is_single_file {
 sub git_commit_info {
  my ($commit, $id, $desc) = @_;
 
- return ($id, $desc) if ((which("git") eq "") || !(-e ".git"));
+ return ($id, $desc) if ((which("git") eq "") || !(-e "$gitroot"));
 
  my $output = `${git_command} log --no-color --format='%H %s' -1 $commit 2>&1`;
  $output =~ s/^\s*//gm;
@@ -1026,7 +1028,7 @@ sub git_commit_info {
 
 # If input is git commits, extract all commits from the commit expressions.
 # For example, HEAD-3 means we need check 'HEAD, HEAD~1, HEAD~2'.
-die "$P: No git repository found\n" if ($git && !-e ".git");
+die "$P: No git repository found\n" if ($git && !-e "$gitroot");
 
 if ($git) {
  my @commits = ();