Add back Parameter value caching. Add hack to avoid changing the function signature of Parameter.get_value(). SystemRDL/PeakRDL-regblock#162

Author: amykyta3

src/systemrdl/core/parameter.py

@@ -14,16 +14,32 @@ def __init__(self, param_type: 'rdltypes.PreElabRDLType', name: str, default_exp
 
         self.expr = default_expr
 
+        self._cached_value: Any = None
 
-    def get_value(self, assignee_node: 'Node') -> Any:
+
+    def get_value(self, assignee_node: Optional['Node'] = None) -> Any:
         """
         Evaluate self.expr to get the parameter's value
+
+        HACK:
+        assignee_node is normally ALWAYS required. However by the time a design
+        is elaborated, the parameter will have been evaluated and the cached
+        value available. This lets end-users avoid providing an assignee node if
+        querying the value via Node.inst.parameters[...].get_value()
+        Making the argument optional is a workaround for https://github.com/SystemRDL/PeakRDL-regblock/issues/162
+        Once <Parameter> truly gets hidden from the public API (No more user
+        access to Node.inst...), clean this up and make assignee_node not optional
         """
+        if self._cached_value is not None:
+            return self._cached_value
+
         if self.expr is None:
             # No expression was assigned
             return None
 
-        return self.expr.get_value(assignee_node=assignee_node)
+        assert assignee_node is not None
+        self._cached_value = self.expr.get_value(assignee_node=assignee_node)
+        return self._cached_value
 
 
     def get_normalized_parameter(self, assignee_node: 'Node') -> str:
@@ -35,3 +51,14 @@ def get_normalized_parameter(self, assignee_node: 'Node') -> str:
             <parameter name> + "_" + <normalized value>
         """
         return self.name + "_" + normalize(self.get_value(assignee_node))
+
+    def __copy__(self) -> 'Parameter':
+        cls = self.__class__
+        result = cls.__new__(cls)
+
+        result.name = self.name
+        result.param_type = self.param_type
+        result.expr = self.expr
+        result._cached_value = None
+
+        return result

src/systemrdl/node.py

@@ -31,6 +31,13 @@ def __init__(self, inst: comp.Component, env: 'RDLEnvironment', parent: Optional
         self.env = env
 
         #: Reference to :class:`~systemrdl.component.Component` that instantiates this node
+        #:
+        #: .. deprecated:: 1.30.0
+        #:   Querying the internal ``Component`` objects is no longer recommended.
+        #:
+        #:   Equivalents for most concepts have been made available as direct
+        #:   methods or properties of the :class:`Node` objects. It is strongly
+        #:   recommended to use these instead to prevent compatibility issues.
         self.inst = inst
 
         #: Reference to parent :class:`~Node`

test/rdl_src/elab_params.rdl

@@ -4,7 +4,8 @@ addrmap elab_params #(
     longint unsigned INT = 1,
     longint unsigned INTARR[]= '{2, 3},
     onwritetype ONWR = woset,
-    boolean BOOL = true
+    boolean BOOL = true,
+    string UNUSED_STR = "asdf"
 ) {
     reg reg_t #(
         longint unsigned WIDTH = 4

test/test_multiple_elab.py

@@ -2,6 +2,7 @@
 import os
 
 from systemrdl import RDLCompiler
+from systemrdl import rdltypes
 
 from unittest_utils import TestPrinter
 
@@ -47,14 +48,43 @@ def test_multi_elab_params(self):
         rdlc = RDLCompiler(message_printer=TestPrinter())
         rdlc.compile_file(os.path.join(this_dir, "rdl_src/elab_params.rdl"))
 
+        print("1")
         default_root = rdlc.elaborate("elab_params")
+        print("2")
         W10_root = rdlc.elaborate("elab_params", parameters={
+            "STR": "ovr1",
             "INT": 10,
+            "INTARR": [20, 30],
+            "UNUSED_STR": "ovr2",
         })
 
         self.assertEqual(default_root.top.find_by_path("r1.f").width, 1)
         self.assertEqual(W10_root.top.find_by_path("r1.f").width, 10)
 
+        # Test old parameter API - Was not explicitly made a private API!
+        expected = {
+            "STR": "default",
+            "INT": 1,
+            "INTARR": [2, 3],
+            "ONWR": rdltypes.OnWriteType.woset,
+            "BOOL": True,
+            "UNUSED_STR": "asdf",
+        }
+        for param in default_root.top.inst.parameters:
+            self.assertEqual(expected[param.name], param.get_value())
+
+        expected = {
+            "STR": "ovr1",
+            "INT": 10,
+            "INTARR": [20, 30],
+            "ONWR": rdltypes.OnWriteType.woset,
+            "BOOL": True,
+            "UNUSED_STR": "ovr2",
+        }
+        for param in W10_root.top.inst.parameters:
+            self.assertEqual(expected[param.name], param.get_value())
+
+
     def test_multi_elab_common_dpa(self):
         rdlc = RDLCompiler(message_printer=TestPrinter())
         rdlc.compile_file(os.path.join(this_dir, "rdl_src/shared_dpa.rdl"))