dts: edtlib: Turn edt.required_by()/depends_on() into Node attributes

Turns

    edt.required_by(node)
    edt.depends_on(node)

into

    node.required_by
    node.depends_on

which might be a bit more readable.

One drawback is that @property hides that there's some slight overhead
in accessing them, but I suspect it won't be meaningful. Caching could
be added if it ever turns out to be.

Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>

scripts/dts/edtlib.py

@@ -161,18 +161,6 @@ class EDT:
         return "<EDT for '{}', binding directories '{}'>".format(
             self.dts_path, self.bindings_dirs)
 
-    def required_by(self, node):
-        """
-        Returns a list of Nodes that have direct dependencies on 'node'.
-        """
-        return self._graph.required_by(node)
-
-    def depends_on(self, node):
-        """
-        Returns a list of Nodes on which 'node' directly depends.
-        """
-        return self._graph.depends_on(node)
-
     def scc_order(self):
         """
         Returns a list of lists of Nodes where all elements of each list
@@ -655,6 +643,12 @@ class Node:
       The ordinal is defined for all Nodes including those that are not
       'enabled', and is unique among nodes in its EDT 'nodes' list.
 
+    required_by:
+      A list with the nodes that directly depend on the node
+
+    depends_on:
+      A list with the nodes that the node directly depends on
+
     enabled:
       True unless the node has 'status = "disabled"'
 
@@ -771,6 +765,16 @@ class Node:
         return {name: self.edt._node2enode[node]
                 for name, node in self._node.nodes.items()}
 
+    @property
+    def required_by(self):
+        "See the class docstring"
+        return self.edt._graph.required_by(self)
+
+    @property
+    def depends_on(self):
+        "See the class docstring"
+        return self.edt._graph.depends_on(self)
+
     @property
     def enabled(self):
         "See the class docstring"

scripts/dts/gen_defines.py

@@ -70,16 +70,16 @@ Directories with bindings:
                 continue
 
             requires_text = ""
-            if edt.depends_on(node):
+            if node.depends_on:
                 requires_text = "Requires:\n"
-                for depends in edt.depends_on(node):
+                for depends in node.depends_on:
                     requires_text += "  {} {}\n".format(depends.dep_ordinal, depends.path)
                 requires_text += "\n"
 
             supports_text = ""
-            if edt.required_by(node):
+            if node.required_by:
                 supports_text = "Supports:\n"
-                for required in edt.required_by(node):
+                for required in node.required_by:
                     supports_text += "  {} {}\n".format(required.dep_ordinal, required.path)
                 supports_text += "\n"
 

scripts/dts/testedtlib.py

@@ -225,10 +225,10 @@ warning: "#cells:" in test-bindings/deprecated.yaml is deprecated and will be re
 
     verify_eq(edt.get_node("/").dep_ordinal, 0)
     verify_eq(edt.get_node("/in-dir-1").dep_ordinal, 1)
-    if edt.get_node("/") not in edt.depends_on(edt.get_node("/in-dir-1")):
-        fail("/ depends-on /in-dir-1")
-    if edt.get_node("/in-dir-1") not in edt.required_by(edt.get_node("/")):
-        fail("/in-dir-1 required-by /")
+    if edt.get_node("/") not in edt.get_node("/in-dir-1").depends_on:
+        fail("/ should be a direct dependency of /in-dir-1")
+    if edt.get_node("/in-dir-1") not in edt.get_node("/").required_by:
+        fail("/in-dir-1 should directly depend on /")
 
     print("all tests passed")