7 files changed, 697 insertions, 0 deletions

diff --git a/scripts/lib/checklayer/__init__.py b/scripts/lib/checklayer/__init__.py
new file mode 100644
index 0000000000..6c2b86a79a
--- /dev/null
+++ b/scripts/lib/checklayer/__init__.py
@@ -0,0 +1,392 @@
+# Yocto Project layer check tool
+#
+# Copyright (C) 2017 Intel Corporation
+# Released under the MIT license (see COPYING.MIT)
+
+import os
+import re
+import subprocess
+from enum import Enum
+
+import bb.tinfoil
+
+class LayerType(Enum):
+    BSP = 0
+    DISTRO = 1
+    SOFTWARE = 2
+    ERROR_NO_LAYER_CONF = 98
+    ERROR_BSP_DISTRO = 99
+
+def _get_configurations(path):
+    configs = []
+
+    for f in os.listdir(path):
+        file_path = os.path.join(path, f)
+        if os.path.isfile(file_path) and f.endswith('.conf'):
+            configs.append(f[:-5]) # strip .conf
+    return configs
+
+def _get_layer_collections(layer_path, lconf=None, data=None):
+    import bb.parse
+    import bb.data
+
+    if lconf is None:
+        lconf = os.path.join(layer_path, 'conf', 'layer.conf')
+
+    if data is None:
+        ldata = bb.data.init()
+        bb.parse.init_parser(ldata)
+    else:
+        ldata = data.createCopy()
+
+    ldata.setVar('LAYERDIR', layer_path)
+    try:
+        ldata = bb.parse.handle(lconf, ldata, include=True)
+    except BaseException as exc:
+        raise LayerError(exc)
+    ldata.expandVarref('LAYERDIR')
+
+    collections = (ldata.getVar('BBFILE_COLLECTIONS', True) or '').split()
+    if not collections:
+        name = os.path.basename(layer_path)
+        collections = [name]
+
+    collections = {c: {} for c in collections}
+    for name in collections:
+        priority = ldata.getVar('BBFILE_PRIORITY_%s' % name, True)
+        pattern = ldata.getVar('BBFILE_PATTERN_%s' % name, True)
+        depends = ldata.getVar('LAYERDEPENDS_%s' % name, True)
+        collections[name]['priority'] = priority
+        collections[name]['pattern'] = pattern
+        collections[name]['depends'] = depends
+
+    return collections
+
+def _detect_layer(layer_path):
+    """
+        Scans layer directory to detect what type of layer
+        is BSP, Distro or Software.
+
+        Returns a dictionary with layer name, type and path.
+    """
+
+    layer = {}
+    layer_name = os.path.basename(layer_path)
+
+    layer['name'] = layer_name
+    layer['path'] = layer_path
+    layer['conf'] = {}
+
+    if not os.path.isfile(os.path.join(layer_path, 'conf', 'layer.conf')):
+        layer['type'] = LayerType.ERROR_NO_LAYER_CONF
+        return layer
+
+    machine_conf = os.path.join(layer_path, 'conf', 'machine')
+    distro_conf = os.path.join(layer_path, 'conf', 'distro')
+
+    is_bsp = False
+    is_distro = False
+
+    if os.path.isdir(machine_conf):
+        machines = _get_configurations(machine_conf)
+        if machines:
+            is_bsp = True
+
+    if os.path.isdir(distro_conf):
+        distros = _get_configurations(distro_conf)
+        if distros:
+            is_distro = True
+
+    if is_bsp and is_distro:
+        layer['type'] = LayerType.ERROR_BSP_DISTRO
+    elif is_bsp:
+        layer['type'] = LayerType.BSP
+        layer['conf']['machines'] = machines
+    elif is_distro:
+        layer['type'] = LayerType.DISTRO
+        layer['conf']['distros'] = distros
+    else:
+        layer['type'] = LayerType.SOFTWARE
+
+    layer['collections'] = _get_layer_collections(layer['path'])
+
+    return layer
+
+def detect_layers(layer_directories, no_auto):
+    layers = []
+
+    for directory in layer_directories:
+        directory = os.path.realpath(directory)
+        if directory[-1] == '/':
+            directory = directory[0:-1]
+
+        if no_auto:
+            conf_dir = os.path.join(directory, 'conf')
+            if os.path.isdir(conf_dir):
+                layer = _detect_layer(directory)
+                if layer:
+                    layers.append(layer)
+        else:
+            for root, dirs, files in os.walk(directory):
+                dir_name = os.path.basename(root)
+                conf_dir = os.path.join(root, 'conf')
+                if os.path.isdir(conf_dir):
+                    layer = _detect_layer(root)
+                    if layer:
+                        layers.append(layer)
+
+    return layers
+
+def _find_layer_depends(depend, layers):
+    for layer in layers:
+        for collection in layer['collections']:
+            if depend == collection:
+                return layer
+    return None
+
+def add_layer_dependencies(bblayersconf, layer, layers, logger):
+    def recurse_dependencies(depends, layer, layers, logger, ret = []):
+        logger.debug('Processing dependencies %s for layer %s.' % \
+                    (depends, layer['name']))
+
+        for depend in depends.split():
+            # core (oe-core) is suppose to be provided
+            if depend == 'core':
+                continue
+
+            layer_depend = _find_layer_depends(depend, layers)
+            if not layer_depend:
+                logger.error('Layer %s depends on %s and isn\'t found.' % \
+                        (layer['name'], depend))
+                ret = None
+                continue
+
+            # We keep processing, even if ret is None, this allows us to report
+            # multiple errors at once
+            if ret is not None and layer_depend not in ret:
+                ret.append(layer_depend)
+
+            # Recursively process...
+            if 'collections' not in layer_depend:
+                continue
+
+            for collection in layer_depend['collections']:
+                collect_deps = layer_depend['collections'][collection]['depends']
+                if not collect_deps:
+                    continue
+                ret = recurse_dependencies(collect_deps, layer_depend, layers, logger, ret)
+
+        return ret
+
+    layer_depends = []
+    for collection in layer['collections']:
+        depends = layer['collections'][collection]['depends']
+        if not depends:
+            continue
+
+        layer_depends = recurse_dependencies(depends, layer, layers, logger, layer_depends)
+
+    # Note: [] (empty) is allowed, None is not!
+    if layer_depends is None:
+        return False
+    else:
+        # Don't add a layer that is already present.
+        added = set()
+        output = check_command('Getting existing layers failed.', 'bitbake-layers show-layers').decode('utf-8')
+        for layer, path, pri in re.findall(r'^(\S+) +([^\n]*?) +(\d+)$', output, re.MULTILINE):
+            added.add(path)
+
+        for layer_depend in layer_depends:
+            name = layer_depend['name']
+            path = layer_depend['path']
+            if path in added:
+                continue
+            else:
+                added.add(path)
+            logger.info('Adding layer dependency %s' % name)
+            with open(bblayersconf, 'a+') as f:
+                f.write("\nBBLAYERS += \"%s\"\n" % path)
+    return True
+
+def add_layer(bblayersconf, layer, layers, logger):
+    logger.info('Adding layer %s' % layer['name'])
+    with open(bblayersconf, 'a+') as f:
+        f.write("\nBBLAYERS += \"%s\"\n" % layer['path'])
+
+    return True
+
+def check_command(error_msg, cmd):
+    '''
+    Run a command under a shell, capture stdout and stderr in a single stream,
+    throw an error when command returns non-zero exit code. Returns the output.
+    '''
+
+    p = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
+    output, _ = p.communicate()
+    if p.returncode:
+        msg = "%s\nCommand: %s\nOutput:\n%s" % (error_msg, cmd, output.decode('utf-8'))
+        raise RuntimeError(msg)
+    return output
+
+def get_signatures(builddir, failsafe=False, machine=None):
+    import re
+
+    # some recipes needs to be excluded like meta-world-pkgdata
+    # because a layer can add recipes to a world build so signature
+    # will be change
+    exclude_recipes = ('meta-world-pkgdata',)
+
+    sigs = {}
+    tune2tasks = {}
+
+    cmd = ''
+    if machine:
+        cmd += 'MACHINE=%s ' % machine
+    cmd += 'bitbake '
+    if failsafe:
+        cmd += '-k '
+    cmd += '-S none world'
+    sigs_file = os.path.join(builddir, 'locked-sigs.inc')
+    if os.path.exists(sigs_file):
+        os.unlink(sigs_file)
+    try:
+        check_command('Generating signatures failed. This might be due to some parse error and/or general layer incompatibilities.',
+                      cmd)
+    except RuntimeError as ex:
+        if failsafe and os.path.exists(sigs_file):
+            # Ignore the error here. Most likely some recipes active
+            # in a world build lack some dependencies. There is a
+            # separate test_machine_world_build which exposes the
+            # failure.
+            pass
+        else:
+            raise
+
+    sig_regex = re.compile("^(?P<task>.*:.*):(?P<hash>.*) .$")
+    tune_regex = re.compile("(^|\s)SIGGEN_LOCKEDSIGS_t-(?P<tune>\S*)\s*=\s*")
+    current_tune = None
+    with open(sigs_file, 'r') as f:
+        for line in f.readlines():
+            line = line.strip()
+            t = tune_regex.search(line)
+            if t:
+                current_tune = t.group('tune')
+            s = sig_regex.match(line)
+            if s:
+                exclude = False
+                for er in exclude_recipes:
+                    (recipe, task) = s.group('task').split(':')
+                    if er == recipe:
+                        exclude = True
+                        break
+                if exclude:
+                    continue
+
+                sigs[s.group('task')] = s.group('hash')
+                tune2tasks.setdefault(current_tune, []).append(s.group('task'))
+
+    if not sigs:
+        raise RuntimeError('Can\'t load signatures from %s' % sigs_file)
+
+    return (sigs, tune2tasks)
+
+def get_depgraph(targets=['world'], failsafe=False):
+    '''
+    Returns the dependency graph for the given target(s).
+    The dependency graph is taken directly from DepTreeEvent.
+    '''
+    depgraph = None
+    with bb.tinfoil.Tinfoil() as tinfoil:
+        tinfoil.prepare(config_only=False)
+        tinfoil.set_event_mask(['bb.event.NoProvider', 'bb.event.DepTreeGenerated', 'bb.command.CommandCompleted'])
+        if not tinfoil.run_command('generateDepTreeEvent', targets, 'do_build'):
+            raise RuntimeError('starting generateDepTreeEvent failed')
+        while True:
+            event = tinfoil.wait_event(timeout=1000)
+            if event:
+                if isinstance(event, bb.command.CommandFailed):
+                    raise RuntimeError('Generating dependency information failed: %s' % event.error)
+                elif isinstance(event, bb.command.CommandCompleted):
+                    break
+                elif isinstance(event, bb.event.NoProvider):
+                    if failsafe:
+                        # The event is informational, we will get information about the
+                        # remaining dependencies eventually and thus can ignore this
+                        # here like we do in get_signatures(), if desired.
+                        continue
+                    if event._reasons:
+                        raise RuntimeError('Nothing provides %s: %s' % (event._item, event._reasons))
+                    else:
+                        raise RuntimeError('Nothing provides %s.' % (event._item))
+                elif isinstance(event, bb.event.DepTreeGenerated):
+                    depgraph = event._depgraph
+
+    if depgraph is None:
+        raise RuntimeError('Could not retrieve the depgraph.')
+    return depgraph
+
+def compare_signatures(old_sigs, curr_sigs):
+    '''
+    Compares the result of two get_signatures() calls. Returns None if no
+    problems found, otherwise a string that can be used as additional
+    explanation in self.fail().
+    '''
+    # task -> (old signature, new signature)
+    sig_diff = {}
+    for task in old_sigs:
+        if task in curr_sigs and \
+           old_sigs[task] != curr_sigs[task]:
+            sig_diff[task] = (old_sigs[task], curr_sigs[task])
+
+    if not sig_diff:
+        return None
+
+    # Beware, depgraph uses task=<pn>.<taskname> whereas get_signatures()
+    # uses <pn>:<taskname>. Need to convert sometimes. The output follows
+    # the convention from get_signatures() because that seems closer to
+    # normal bitbake output.
+    def sig2graph(task):
+        pn, taskname = task.rsplit(':', 1)
+        return pn + '.' + taskname
+    def graph2sig(task):
+        pn, taskname = task.rsplit('.', 1)
+        return pn + ':' + taskname
+    depgraph = get_depgraph(failsafe=True)
+    depends = depgraph['tdepends']
+
+    # If a task A has a changed signature, but none of its
+    # dependencies, then we need to report it because it is
+    # the one which introduces a change. Any task depending on
+    # A (directly or indirectly) will also have a changed
+    # signature, but we don't need to report it. It might have
+    # its own changes, which will become apparent once the
+    # issues that we do report are fixed and the test gets run
+    # again.
+    sig_diff_filtered = []
+    for task, (old_sig, new_sig) in sig_diff.items():
+        deps_tainted = False
+        for dep in depends.get(sig2graph(task), ()):
+            if graph2sig(dep) in sig_diff:
+                deps_tainted = True
+                break
+        if not deps_tainted:
+            sig_diff_filtered.append((task, old_sig, new_sig))
+
+    msg = []
+    msg.append('%d signatures changed, initial differences (first hash before, second after):' %
+               len(sig_diff))
+    for diff in sorted(sig_diff_filtered):
+        recipe, taskname = diff[0].rsplit(':', 1)
+        cmd = 'bitbake-diffsigs --task %s %s --signature %s %s' % \
+              (recipe, taskname, diff[1], diff[2])
+        msg.append('   %s: %s -> %s' % diff)
+        msg.append('      %s' % cmd)
+        try:
+            output = check_command('Determining signature difference failed.',
+                                   cmd).decode('utf-8')
+        except RuntimeError as error:
+            output = str(error)
+        if output:
+            msg.extend(['      ' + line for line in output.splitlines()])
+            msg.append('')
+    return '\n'.join(msg)
diff --git a/scripts/lib/checklayer/case.py b/scripts/lib/checklayer/case.py
new file mode 100644
index 0000000000..9dd00412e5
--- /dev/null
+++ b/scripts/lib/checklayer/case.py
@@ -0,0 +1,7 @@
+# Copyright (C) 2017 Intel Corporation
+# Released under the MIT license (see COPYING.MIT)
+
+from oeqa.core.case import OETestCase
+
+class OECheckLayerTestCase(OETestCase):
+    pass
diff --git a/scripts/lib/checklayer/cases/__init__.py b/scripts/lib/checklayer/cases/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/scripts/lib/checklayer/cases/__init__.py
diff --git a/scripts/lib/checklayer/cases/bsp.py b/scripts/lib/checklayer/cases/bsp.py
new file mode 100644
index 0000000000..b6b611be73
--- /dev/null
+++ b/scripts/lib/checklayer/cases/bsp.py
@@ -0,0 +1,204 @@
+# Copyright (C) 2017 Intel Corporation
+# Released under the MIT license (see COPYING.MIT)
+
+import unittest
+
+from checklayer import LayerType, get_signatures, check_command, get_depgraph
+from checklayer.case import OECheckLayerTestCase
+
+class BSPCheckLayer(OECheckLayerTestCase):
+    @classmethod
+    def setUpClass(self):
+        if self.tc.layer['type'] != LayerType.BSP:
+            raise unittest.SkipTest("BSPCheckLayer: Layer %s isn't BSP one." %\
+                self.tc.layer['name'])
+
+    def test_bsp_defines_machines(self):
+        self.assertTrue(self.tc.layer['conf']['machines'], 
+                "Layer is BSP but doesn't defines machines.")
+
+    def test_bsp_no_set_machine(self):
+        from oeqa.utils.commands import get_bb_var
+
+        machine = get_bb_var('MACHINE')
+        self.assertEqual(self.td['bbvars']['MACHINE'], machine,
+                msg="Layer %s modified machine %s -> %s" % \
+                    (self.tc.layer['name'], self.td['bbvars']['MACHINE'], machine))
+
+
+    def test_machine_world(self):
+        '''
+        "bitbake world" is expected to work regardless which machine is selected.
+        BSP layers sometimes break that by enabling a recipe for a certain machine
+        without checking whether that recipe actually can be built in the current
+        distro configuration (for example, OpenGL might not enabled).
+
+        This test iterates over all machines. It would be nicer to instantiate
+        it once per machine. It merely checks for errors during parse
+        time. It does not actually attempt to build anything.
+        '''
+
+        if not self.td['machines']:
+            self.skipTest('No machines set with --machines.')
+        msg = []
+        for machine in self.td['machines']:
+            # In contrast to test_machine_signatures() below, errors are fatal here.
+            try:
+                get_signatures(self.td['builddir'], failsafe=False, machine=machine)
+            except RuntimeError as ex:
+                msg.append(str(ex))
+        if msg:
+            msg.insert(0, 'The following machines broke a world build:')
+            self.fail('\n'.join(msg))
+
+    def test_machine_signatures(self):
+        '''
+        Selecting a machine may only affect the signature of tasks that are specific
+        to that machine. In other words, when MACHINE=A and MACHINE=B share a recipe
+        foo and the output of foo, then both machine configurations must build foo
+        in exactly the same way. Otherwise it is not possible to use both machines
+        in the same distribution.
+
+        This criteria can only be tested by testing different machines in combination,
+        i.e. one main layer, potentially several additional BSP layers and an explicit
+        choice of machines:
+        yocto-check-layer --additional-layers .../meta-intel --machines intel-corei7-64 imx6slevk -- .../meta-freescale
+        '''
+
+        if not self.td['machines']:
+            self.skipTest('No machines set with --machines.')
+
+        # Collect signatures for all machines that we are testing
+        # and merge that into a hash:
+        # tune -> task -> signature -> list of machines with that combination
+        #
+        # It is an error if any tune/task pair has more than one signature,
+        # because that implies that the machines that caused those different
+        # signatures do not agree on how to execute the task.
+        tunes = {}
+        # Preserve ordering of machines as chosen by the user.
+        for machine in self.td['machines']:
+            curr_sigs, tune2tasks = get_signatures(self.td['builddir'], failsafe=True, machine=machine)
+            # Invert the tune -> [tasks] mapping.
+            tasks2tune = {}
+            for tune, tasks in tune2tasks.items():
+                for task in tasks:
+                    tasks2tune[task] = tune
+            for task, sighash in curr_sigs.items():
+                tunes.setdefault(tasks2tune[task], {}).setdefault(task, {}).setdefault(sighash, []).append(machine)
+
+        msg = []
+        pruned = 0
+        last_line_key = None
+        # do_fetch, do_unpack, ..., do_build
+        taskname_list = []
+        if tunes:
+            # The output below is most useful when we start with tasks that are at
+            # the bottom of the dependency chain, i.e. those that run first. If
+            # those tasks differ, the rest also does.
+            #
+            # To get an ordering of tasks, we do a topological sort of the entire
+            # depgraph for the base configuration, then on-the-fly flatten that list by stripping
+            # out the recipe names and removing duplicates. The base configuration
+            # is not necessarily representative, but should be close enough. Tasks
+            # that were not encountered get a default priority.
+            depgraph = get_depgraph()
+            depends = depgraph['tdepends']
+            WHITE = 1
+            GRAY = 2
+            BLACK = 3
+            color = {}
+            found = set()
+            def visit(task):
+                color[task] = GRAY
+                for dep in depends.get(task, ()):
+                    if color.setdefault(dep, WHITE) == WHITE:
+                        visit(dep)
+                color[task] = BLACK
+                pn, taskname = task.rsplit('.', 1)
+                if taskname not in found:
+                    taskname_list.append(taskname)
+                    found.add(taskname)
+            for task in depends.keys():
+                if color.setdefault(task, WHITE) == WHITE:
+                    visit(task)
+
+        taskname_order = dict([(task, index) for index, task in enumerate(taskname_list) ])
+        def task_key(task):
+            pn, taskname = task.rsplit(':', 1)
+            return (pn, taskname_order.get(taskname, len(taskname_list)), taskname)
+
+        for tune in sorted(tunes.keys()):
+            tasks = tunes[tune]
+            # As for test_signatures it would be nicer to sort tasks
+            # by dependencies here, but that is harder because we have
+            # to report on tasks from different machines, which might
+            # have different dependencies. We resort to pruning the
+            # output by reporting only one task per recipe if the set
+            # of machines matches.
+            #
+            # "bitbake-diffsigs -t -s" is intelligent enough to print
+            # diffs recursively, so often it does not matter that much
+            # if we don't pick the underlying difference
+            # here. However, sometimes recursion fails
+            # (https://bugzilla.yoctoproject.org/show_bug.cgi?id=6428).
+            #
+            # To mitigate that a bit, we use a hard-coded ordering of
+            # tasks that represents how they normally run and prefer
+            # to print the ones that run first.
+            for task in sorted(tasks.keys(), key=task_key):
+                signatures = tasks[task]
+                # do_build can be ignored: it is know to have
+                # different signatures in some cases, for example in
+                # the allarch ca-certificates due to RDEPENDS=openssl.
+                # That particular dependency is whitelisted via
+                # SIGGEN_EXCLUDE_SAFE_RECIPE_DEPS, but still shows up
+                # in the sstate signature hash because filtering it
+                # out would be hard and running do_build multiple
+                # times doesn't really matter.
+                if len(signatures.keys()) > 1 and \
+                   not task.endswith(':do_build'):
+                    # Error!
+                    #
+                    # Sort signatures by machines, because the hex values don't mean anything.
+                    # => all-arch adwaita-icon-theme:do_build: 1234... (beaglebone, qemux86) != abcdf... (qemux86-64)
+                    #
+                    # Skip the line if it is covered already by the predecessor (same pn, same sets of machines).
+                    pn, taskname = task.rsplit(':', 1)
+                    next_line_key = (pn, sorted(signatures.values()))
+                    if next_line_key != last_line_key:
+                        line = '   %s %s: ' % (tune, task)
+                        line += ' != '.join(['%s (%s)' % (signature, ', '.join([m for m in signatures[signature]])) for
+                                             signature in sorted(signatures.keys(), key=lambda s: signatures[s])])
+                        last_line_key = next_line_key
+                        msg.append(line)
+                        # Randomly pick two mismatched signatures and remember how to invoke
+                        # bitbake-diffsigs for them.
+                        iterator = iter(signatures.items())
+                        a = next(iterator)
+                        b = next(iterator)
+                        diffsig_machines = '(%s) != (%s)' % (', '.join(a[1]), ', '.join(b[1]))
+                        diffsig_params = '-t %s %s -s %s %s' % (pn, taskname, a[0], b[0])
+                    else:
+                        pruned += 1
+
+        if msg:
+            msg.insert(0, 'The machines have conflicting signatures for some shared tasks:')
+            if pruned > 0:
+                msg.append('')
+                msg.append('%d tasks where not listed because some other task of the recipe already differed.' % pruned)
+                msg.append('It is likely that differences from different recipes also have the same root cause.')
+            msg.append('')
+            # Explain how to investigate...
+            msg.append('To investigate, run bitbake-diffsigs -t recipename taskname -s fromsig tosig.')
+            cmd = 'bitbake-diffsigs %s' % diffsig_params
+            msg.append('Example: %s in the last line' % diffsig_machines)
+            msg.append('Command: %s' % cmd)
+            # ... and actually do it automatically for that example, but without aborting
+            # when that fails.
+            try:
+                output = check_command('Comparing signatures failed.', cmd).decode('utf-8')
+            except RuntimeError as ex:
+                output = str(ex)
+            msg.extend(['   ' + line for line in output.splitlines()])
+            self.fail('\n'.join(msg))
diff --git a/scripts/lib/checklayer/cases/common.py b/scripts/lib/checklayer/cases/common.py
new file mode 100644
index 0000000000..a13c1088f0
--- /dev/null
+++ b/scripts/lib/checklayer/cases/common.py
@@ -0,0 +1,53 @@
+# Copyright (C) 2017 Intel Corporation
+# Released under the MIT license (see COPYING.MIT)
+
+import glob
+import os
+import unittest
+from checklayer import get_signatures, LayerType, check_command, get_depgraph, compare_signatures
+from checklayer.case import OECheckLayerTestCase
+
+class CommonCheckLayer(OECheckLayerTestCase):
+    def test_readme(self):
+        # The top-level README file may have a suffix (like README.rst or README.txt).
+        readme_files = glob.glob(os.path.join(self.tc.layer['path'], 'README*'))
+        self.assertTrue(len(readme_files) > 0,
+                        msg="Layer doesn't contains README file.")
+
+        # There might be more than one file matching the file pattern above
+        # (for example, README.rst and README-COPYING.rst). The one with the shortest
+        # name is considered the "main" one.
+        readme_file = sorted(readme_files)[0]
+        data = ''
+        with open(readme_file, 'r') as f:
+            data = f.read()
+        self.assertTrue(data,
+                msg="Layer contains a README file but it is empty.")
+
+    def test_parse(self):
+        check_command('Layer %s failed to parse.' % self.tc.layer['name'],
+                      'bitbake -p')
+
+    def test_show_environment(self):
+        check_command('Layer %s failed to show environment.' % self.tc.layer['name'],
+                      'bitbake -e')
+
+    def test_world(self):
+        '''
+        "bitbake world" is expected to work. test_signatures does not cover that
+        because it is more lenient and ignores recipes in a world build that
+        are not actually buildable, so here we fail when "bitbake -S none world"
+        fails.
+        '''
+        get_signatures(self.td['builddir'], failsafe=False)
+
+    def test_signatures(self):
+        if self.tc.layer['type'] == LayerType.SOFTWARE and \
+           not self.tc.test_software_layer_signatures:
+            raise unittest.SkipTest("Not testing for signature changes in a software layer %s." \
+                     % self.tc.layer['name'])
+
+        curr_sigs, _ = get_signatures(self.td['builddir'], failsafe=True)
+        msg = compare_signatures(self.td['sigs'], curr_sigs)
+        if msg is not None:
+            self.fail('Adding layer %s changed signatures.\n%s' % (self.tc.layer['name'], msg))
diff --git a/scripts/lib/checklayer/cases/distro.py b/scripts/lib/checklayer/cases/distro.py
new file mode 100644
index 0000000000..df1b3035eb
--- /dev/null
+++ b/scripts/lib/checklayer/cases/distro.py
@@ -0,0 +1,26 @@
+# Copyright (C) 2017 Intel Corporation
+# Released under the MIT license (see COPYING.MIT)
+
+import unittest
+
+from checklayer import LayerType
+from checklayer.case import OECheckLayerTestCase
+
+class DistroCheckLayer(OECheckLayerTestCase):
+    @classmethod
+    def setUpClass(self):
+        if self.tc.layer['type'] != LayerType.DISTRO:
+            raise unittest.SkipTest("DistroCheckLayer: Layer %s isn't Distro one." %\
+                self.tc.layer['name'])
+
+    def test_distro_defines_distros(self):
+        self.assertTrue(self.tc.layer['conf']['distros'], 
+                "Layer is BSP but doesn't defines machines.")
+
+    def test_distro_no_set_distros(self):
+        from oeqa.utils.commands import get_bb_var
+
+        distro = get_bb_var('DISTRO')
+        self.assertEqual(self.td['bbvars']['DISTRO'], distro,
+                msg="Layer %s modified distro %s -> %s" % \
+                    (self.tc.layer['name'], self.td['bbvars']['DISTRO'], distro))
diff --git a/scripts/lib/checklayer/context.py b/scripts/lib/checklayer/context.py
new file mode 100644
index 0000000000..1bec2c4103
--- /dev/null
+++ b/scripts/lib/checklayer/context.py
@@ -0,0 +1,15 @@
+# Copyright (C) 2017 Intel Corporation
+# Released under the MIT license (see COPYING.MIT)
+
+import os
+import sys
+import glob
+import re
+
+from oeqa.core.context import OETestContext
+
+class CheckLayerTestContext(OETestContext):
+    def __init__(self, td=None, logger=None, layer=None, test_software_layer_signatures=True):
+        super(CheckLayerTestContext, self).__init__(td, logger)
+        self.layer = layer
+        self.test_software_layer_signatures = test_software_layer_signatures