From 0d4dca10b2ac156b598f96b4dadb44ac7001380b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mart=C3=AD=20Bol=C3=ADvar?= <marti.bolivar@nordicsemi.no>
Date: Tue, 3 Nov 2020 08:34:04 -0800
Subject: [PATCH] scripts: edtlib: child binding compatibles match parents
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Fixes: #29758

Commit 7165b77a81f35bd76fbbdc391f8c76f3d64d58a4 ("scripts: edtlib:
refactor for first class bindings") introduced a Binding class.

Its child_binding instance attribute has a compatible which can be
None. Adjust this behavior so the child Binding object has the same
compatible as the parent binding which ultimately has a compatible.

Without this, sanitycheck's expr_parser is doing some matching on
compatibles in child nodes that is producing unexpected results.

Signed-off-by: Martí Bolívar <marti.bolivar@nordicsemi.no>
---
 scripts/dts/edtlib.py     | 22 +++++++++++++++++++---
 scripts/dts/testedtlib.py |  1 -
 2 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/scripts/dts/edtlib.py b/scripts/dts/edtlib.py
index ce461bef28e..89dccca34bc 100644
--- a/scripts/dts/edtlib.py
+++ b/scripts/dts/edtlib.py
@@ -1390,9 +1390,10 @@ class Binding:
       The free-form description of the binding.
 
     compatible:
-      The compatible string the binding matches. This may be None if the
-      Binding object is a child binding or if it's inferred from node
-      properties.
+      The compatible string the binding matches. This is None if the Binding is
+      inferred from node properties. If the Binding is a child binding, then
+      this will be inherited from the parent binding unless the child binding
+      explicitly sets its own compatible.
 
     prop2specs:
       A collections.OrderedDict mapping property names to PropertySpec objects
@@ -1508,6 +1509,14 @@ class Binding:
             if key.endswith("-cells"):
                 self.specifier2cells[key[:-len("-cells")]] = val
 
+        # Make child binding compatibles match ours if they are missing.
+        if self.compatible is not None:
+            child = self.child_binding
+            while child is not None:
+                if child.compatible is None:
+                    child.compatible = self.compatible
+                child = child.child_binding
+
         # Drop the reference to the open warn file. This is necessary
         # to make this object pickleable, but also allows it to get
         # garbage collected and closed if nobody else is using it.
@@ -1528,8 +1537,15 @@ class Binding:
     @property
     def compatible(self):
         "See the class docstring"
+        if hasattr(self, '_compatible'):
+            return self._compatible
         return self.raw.get('compatible')
 
+    @compatible.setter
+    def compatible(self, compatible):
+        "See the class docstring"
+        self._compatible = compatible
+
     @property
     def bus(self):
         "See the class docstring"
diff --git a/scripts/dts/testedtlib.py b/scripts/dts/testedtlib.py
index 8fc6d244f92..1f901ea3370 100644
--- a/scripts/dts/testedtlib.py
+++ b/scripts/dts/testedtlib.py
@@ -137,7 +137,6 @@ def test_bus():
     assert str(edt.get_node("/buses/foo-bus/node/nested").binding_path) == \
         hpath("test-bindings/device-on-foo-bus.yaml")
 
-@pytest.mark.xfail
 def test_child_binding():
     '''Test 'child-binding:' in bindings'''
     edt = edtlib.EDT("test.dts", ["test-bindings"])