Correction for #224

Signed-off-by: Matthew Ballance <matt.ballance@gmail.com>

Author: mballance

doc/Changelog.md

@@ -1,4 +1,7 @@
 
+## 0.9.2
+- (#224) - Ensure fields within expressions can be referenced
+
 ## 0.9.1
 - (#221) - Correct a random-stability issue due to solve-order directives
 - 

src/vsc/model/expr_indexed_field_ref_model.py

@@ -16,7 +16,7 @@ def __init__(self,
                  idx_t):
         super().__init__()
 
-        if not isinstance(root, (ExprFieldRefModel,ExprArraySubscriptModel)):
+        if not isinstance(root, (ExprFieldRefModel,ExprArraySubscriptModel,ExprIndexedFieldRefModel)):
             raise Exception("unsupported root for an indexed reference: " + str(root))
 
         self.root = root

src/vsc/types.py

@@ -40,6 +40,7 @@
 from vsc.model.expr_rangelist_model import ExprRangelistModel
 from vsc.model.expr_unary_model import ExprUnaryModel
 from vsc.model.field_array_model import FieldArrayModel
+from vsc.model.field_composite_model import FieldCompositeModel
 from vsc.model.field_const_array_model import FieldConstArrayModel
 from vsc.model.field_scalar_model import FieldScalarModel
 from vsc.model.unary_expr_type import UnaryExprType
@@ -49,6 +50,8 @@
 from vsc.impl.expr_mode import get_expr_mode, expr_mode, is_expr_mode
 from vsc.model.expr_array_product_model import ExprArrayProductModel
 from vsc.visitors.model_pretty_printer import ModelPrettyPrinter
+from vsc.visitors.expr2field_visitor import Expr2FieldVisitor
+from vsc.visitors.expr2fieldtype_visitor import Expr2FieldTypeVisitor
 from vsc.model.expr_indexed_dynref_model import ExprIndexedDynRefModel
 from vsc.model.source_info import SourceInfo
 
@@ -172,6 +175,29 @@ def not_inside(self, rhs):
         else:
             raise Exception("Unsupported 'not_inside' argument of type " + str(type(rhs)))
 
+    def __getattr__(self, name):
+        ret = None
+        em = object.__getattribute__(self, "em")
+        fm_t = Expr2FieldTypeVisitor().fieldtype(em)
+
+        if fm_t is not None:
+            if name in fm_t.field_id_m.keys():
+                idx = fm_t.field_id_m[name]
+                ret = expr(ExprIndexedFieldRefModel(em, [idx]))
+            else:
+                raise Exception("Field %s not in type %s" % (name, fm_t.name))
+        else:
+            fm = Expr2FieldVisitor().field(em)
+
+            if name in fm.field_id_m.keys():
+                idx = fm.field_id_m[name]
+                ret = expr(ExprIndexedFieldRefModel(em, [idx]))
+            else:
+                raise Exception("Composite %s does not contain a field \"%s\"" % (
+                    fm.name, name))
+
+        return ret
+
     def __getitem__(self, k):
         if is_expr_mode():
             if isinstance(k, slice):

src/vsc/visitors/expr2fieldtype_visitor.py

@@ -12,7 +12,7 @@
 class Expr2FieldTypeVisitor(ModelVisitor):
     """Traverses an array-reference expression, returning element-type information"""
 
-    DEBUG_EN = False
+    DEBUG_EN = True
 
     def __init__(self):
         super().__init__()
@@ -39,6 +39,9 @@ def visit_field_scalar_array(self, f:FieldArrayModel):
         self.type = f.type_t
         if Expr2FieldTypeVisitor.DEBUG_EN:
             print("--> visit_field_array fm=%s ft=%s" % (str(self.field), str(self.type)))
+
+    def visit_composite_field(self, t):
+        self.type = None
 
     def visit_expr_indexed_fieldref(self, e : ExprIndexedFieldRefModel):
         if Expr2FieldTypeVisitor.DEBUG_EN:
@@ -52,6 +55,14 @@ def visit_expr_array_subscript(self, s : ExprArraySubscriptModel):
             print("--> visit_expr_array_subscript")
         s.lhs.accept(self)
 
+        if Expr2FieldTypeVisitor.DEBUG_EN:
+            print("--> visit_expr_array_subscript(visit_type)")
+        t = self.type
+        self.type = None
+        t.accept(self)
+        if Expr2FieldTypeVisitor.DEBUG_EN:
+            print("<-- visit_expr_array_subscript(visit_type)")
+
         if Expr2FieldTypeVisitor.DEBUG_EN:
             print("<-- visit_expr_array_subscript")
 

ve/unit/test_compound_obj.py

@@ -545,4 +545,29 @@ def test_c(self):
         inst.randomize(debug=0)
         print(inst.c1[0].a[0].value)
         print(inst.c2[0].x[0].value)        
-    
+
+    def test_nested_objects(self):
+
+        @vsc.randobj
+        class Field(object):
+            def __init__(self):
+                self.c = vsc.rand_uint8_t()
+
+
+        @vsc.randobj
+        class Child(object):
+            def __init__(self):
+                self.b = vsc.rand_attr(Field())
+
+
+        @vsc.randobj
+        class Parent(object):
+            def __init__(self):
+                self.a = vsc.rand_list_t(Child(), 2)
+
+            @vsc.constraint
+            def eq_c(self):
+                self.a[0].b.c == self.a[1].b.c
+
+
+        item = Parent()