checklayer: check layer in BBLAYERS before test

layer under test should absent from BBLAYERS when running
yocto-check-layer. This allow to get signatures before layer
under test. There are existing steps to add the layer under
test to BBLAYERS after getting initial signatures.

add steps to check for layer under test in BBLAYERS before
running any test, skip test for the layer if the layer under
test exist in BBLAYERS.

[YOCTO #13176]

(From OE-Core rev: be02e8dbfb0d1decce125322f9f1e11a649756c0)

Signed-off-by: Lee Chee Yang <chee.yang.lee@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/lib/checklayer/__init__.py

@@ -229,6 +229,20 @@ def add_layers(bblayersconf, layers, logger):
                 f.write("\nBBLAYERS += \"%s\"\n" % path)
     return True
 
+def check_bblayers(bblayersconf, layer_path, logger):
+    '''
+    If layer_path found in BBLAYERS return True
+    '''
+    import bb.parse
+    import bb.data
+
+    ldata = bb.parse.handle(bblayersconf, bb.data.init(), include=True)
+    for bblayer in (ldata.getVar('BBLAYERS') or '').split():
+        if os.path.normpath(bblayer) == os.path.normpath(layer_path):
+            return True
+
+    return False
+
 def check_command(error_msg, cmd, cwd=None):
     '''
     Run a command under a shell, capture stdout and stderr in a single stream,

scripts/yocto-check-layer

@@ -24,7 +24,7 @@ import scriptpath
 scriptpath.add_oe_lib_path()
 scriptpath.add_bitbake_lib_path()
 
-from checklayer import LayerType, detect_layers, add_layers, add_layer_dependencies, get_signatures
+from checklayer import LayerType, detect_layers, add_layers, add_layer_dependencies, get_signatures, check_bblayers
 from oeqa.utils.commands import get_bb_vars
 
 PROGNAME = 'yocto-check-layer'
@@ -138,6 +138,13 @@ def main():
                 layer['type'] == LayerType.ERROR_BSP_DISTRO:
             continue
 
+        if check_bblayers(bblayersconf, layer['path'], logger):
+            logger.info("%s already in %s. To capture initial signatures, layer under test should not present "
+               "in BBLAYERS. Please remove %s from BBLAYERS." % (layer['name'], bblayersconf, layer['name']))
+            results[layer['name']] = None
+            results_status[layer['name']] = 'SKIPPED (Layer under test should not present in BBLAYERS)'
+            continue
+
         logger.info('')
         logger.info("Setting up for %s(%s), %s" % (layer['name'], layer['type'],
             layer['path']))