Merge pull request #3 from VyperCore/example-context

Create a context manager for contextual coverage data

fcov/context.py

@@ -0,0 +1,29 @@
+from copy import copy
+from types import SimpleNamespace
+
+class ContextBase:
+    _stack: list["SimpleNamespace"] = [SimpleNamespace()]
+
+    def __init__(self, replace=False, overlay=True, **kwargs):
+        if overlay:
+            self.data = copy(self._stack[-1])
+            for k, v in kwargs.items():
+                if not replace and hasattr(self.data, k):
+                    raise KeyError(f"Context already contains `{k}` and `replace` is False")
+                setattr(self.data, k, v)
+        else:
+            self.data = SimpleNamespace(**kwargs)
+
+    def __enter__(self):
+        self._stack.append(self.data)
+
+    def __exit__(self, _extype, _exval, _extb):
+        self._stack.pop()
+
+    @classmethod
+    def get(cls):
+        if len(cls._stack):
+            return cls._stack[-1]
+        return SimpleNamespace()
+
+class CoverageContext(ContextBase): ...

fcov/covergroup.py

@@ -1,3 +1,7 @@
+from types import SimpleNamespace
+from .context import CoverageContext
+
+
 class Covergroup:
     """This class groups coverpoints together, and adds them to the hierarchy"""
 
@@ -14,7 +18,7 @@ def __init__(self, name, description):
 
         self.coverpoints = {}
         self.covergroups = {}
-        self.setup()
+        self.setup(ctx=CoverageContext.get())
 
     def add_coverpoint(self, coverpoint):
         """
@@ -41,7 +45,7 @@ def add_covergroup(self, covergroup):
         self.covergroups[covergroup.name] = covergroup
         setattr(self, covergroup.name, covergroup)
 
-    def setup(self):
+    def setup(self, ctx: SimpleNamespace):
         raise NotImplementedError("This needs to be implemented by the coverpoint")
 
     def print_tree(self, indent=0):

fcov/coverpoint.py

@@ -6,6 +6,8 @@
 from rich.console import Console
 from rich.table import Table
 
+from .context import CoverageContext
+
 from .axis import Axis
 from .cursor import Cursor
 from .goal import GoalItem
@@ -42,7 +44,7 @@ def __init__(self, name: str, description: str, trigger=None):
         # Instance of Cursor class to increment hit count for a bucket
         self.cursor = Cursor(self)
 
-        self.setup()
+        self.setup(ctx=CoverageContext.get())
 
         self.axis_names = [x.name for x in self.axes]
         # TODO Check if goalsDict only has 1 entry
@@ -53,6 +55,9 @@ def __init__(self, name: str, description: str, trigger=None):
             if goal:
                 self._cvg_goals[cursor] = goal
 
+    def setup(self, ctx: SimpleNamespace):
+        raise NotImplementedError("This needs to be implemented by the coverpoint")
+
     def all_axis_value_combinations(self):
         axis_values = []
         for axis in self.axes:

fcov/example.py

@@ -1,3 +1,4 @@
+from .context import CoverageContext
 from .covergroup import Covergroup
 from .coverpoint import Coverpoint
 from .sampler import Sampler
@@ -20,7 +21,7 @@ class MyCoverpoint(Coverpoint):
     def __init__(self, name: str, description: str, trigger=None):
         super().__init__(name, description, trigger=None)
 
-    def setup(self):
+    def setup(self, ctx):
         self.add_axis(
             name="my_axis_1",
             values=[0, 1, [2, 3]],
@@ -65,15 +66,15 @@ def sample(self, trace):
 
 # covergroups
 class MyCovergroup(Covergroup):
-    def setup(self):
+    def setup(self, ctx):
         self.add_coverpoint(MyCoverpoint(name="my_coverpoint", description="A lovely coverpoint"))
         self.add_coverpoint(
             MyCoverpoint(name="another_coverpoint", description="A rather spiffing coverpoint")
         )
 
 
 class MyBigCoverGroup(Covergroup):
-    def setup(self):
+    def setup(self, ctx):
         self.add_covergroup(
             MyCovergroup(name="my_covergroup", description="A group of coverpoints")
         )
@@ -103,8 +104,8 @@ def create_trace(self):
 
 if __name__ == "__main__":
     # testbench
-
-    cvg = MyBigCoverGroup(name="my_big_covergroup", description="A group of stuff")
+    with CoverageContext(isa="THIS IS AN ISA"):
+        cvg = MyBigCoverGroup(name="my_big_covergroup", description="A group of stuff")
 
     cvg.print_tree()
     cvg.my_covergroup.print_tree()