externalsrc: Detect code changes in submodules

The srctree_hash was calculated only from main source directory ignoring
changes in submodules.

[YOCTO #13748]

Use submodule--helper to determine all submodules, and calculate hash
from all git tree objects names combined.

Signed-off-by: Tomasz Dziendzielski <tomasz.dziendzielski@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 11 insertions, 1 deletions

diff --git a/meta/classes/externalsrc.bbclass b/meta/classes/externalsrc.bbclass
index 7a7d31e311..64e94e3301 100644
--- a/meta/classes/externalsrc.bbclass
+++ b/meta/classes/externalsrc.bbclass
@@ -190,6 +190,7 @@ def srctree_hash_files(d, srcdir=None):
     import shutil
     import subprocess
     import tempfile
+    import hashlib
 
     s_dir = srcdir or d.getVar('EXTERNALSRC')
     git_dir = None
@@ -214,7 +215,16 @@ def srctree_hash_files(d, srcdir=None):
             env = os.environ.copy()
             env['GIT_INDEX_FILE'] = tmp_index.name
             subprocess.check_output(['git', 'add', '-A', '.'], cwd=s_dir, env=env)
-            sha1 = subprocess.check_output(['git', 'write-tree'], cwd=s_dir, env=env).decode("utf-8")
+            git_sha1 = subprocess.check_output(['git', 'write-tree'], cwd=s_dir, env=env).decode("utf-8")
+            submodule_helper = subprocess.check_output(['git', 'submodule--helper', 'list'], cwd=s_dir, env=env).decode("utf-8")
+            for line in submodule_helper.splitlines():
+                module_dir = os.path.join(s_dir, line.rsplit(maxsplit=1)[1])
+                proc = subprocess.Popen(['git', 'add', '-A', '.'], cwd=module_dir, env=env, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
+                proc.communicate()
+                proc = subprocess.Popen(['git', 'write-tree'], cwd=module_dir, env=env, stdout=subprocess.PIPE, stderr=subprocess.DEVNULL)
+                stdout, _ = proc.communicate()
+                git_sha1 += stdout.decode("utf-8")
+            sha1 = hashlib.sha1(git_sha1.encode("utf-8")).hexdigest()
         with open(oe_hash_file, 'w') as fobj:
             fobj.write(sha1)
         ret = oe_hash_file + ':True'