tracer: factor out get_src_loc().

nmigen/hdl/ast.py

@@ -39,12 +39,7 @@ class Value(metaclass=ABCMeta):
 
     def __init__(self, src_loc_at=0):
         super().__init__()
-
-        tb = traceback.extract_stack(limit=3 + src_loc_at)
-        if len(tb) < src_loc_at:
-            self.src_loc = None
-        else:
-            self.src_loc = (tb[0].filename, tb[0].lineno)
+        self.src_loc = tracer.get_src_loc(1 + src_loc_at)
 
     def __bool__(self):
         raise TypeError("Attempted to convert nMigen value to boolean")
@@ -721,8 +716,7 @@ class Array(MutableSequence):
     def __getitem__(self, index):
         if isinstance(index, Value):
             if self._mutable:
-                tb = traceback.extract_stack(limit=2)
-                self._proxy_at = (tb[0].filename, tb[0].lineno)
+                self._proxy_at = tracer.get_src_loc()
                 self._mutable  = False
             return ArrayProxy(self, index)
         else:

nmigen/hdl/mem.py

@@ -1,5 +1,3 @@
-import traceback
-
 from .. import tracer
 from .ast import *
 from .ir import Instance
@@ -17,15 +15,13 @@ class Memory:
             raise TypeError("Memory depth must be a non-negative integer, not '{!r}'"
                             .format(depth))
 
-        tb = traceback.extract_stack(limit=2)
-        self.src_loc = (tb[0].filename, tb[0].lineno)
-
         if name is None:
             try:
                 name = tracer.get_var_name(depth=2)
             except tracer.NameNotFound:
                 name = "$memory"
-        self.name = name
+        self.name    = name
+        self.src_loc = tracer.get_src_loc()
 
         self.width = width
         self.depth = depth