From 0c08f2c31e96af4ac1a8816df0a2782ae1232d7b Mon Sep 17 00:00:00 2001
From: Vasileios Karakasis <vkarak@gmail.com>
Date: Tue, 22 Nov 2022 22:57:21 +0100
Subject: [PATCH] Fix variable aliasing

---
 reframe/core/variables.py  | 30 +++++++++++++++++++++++++++---
 unittests/test_pipeline.py |  5 ++---
 2 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/reframe/core/variables.py b/reframe/core/variables.py
index 961744e850..f285d39561 100644
--- a/reframe/core/variables.py
+++ b/reframe/core/variables.py
@@ -7,8 +7,8 @@
 # Functionality to build extensible variable spaces into ReFrame tests.
 #
 
-import math
 import copy
+import math
 
 import reframe.core.fields as fields
 import reframe.core.namespaces as namespaces
@@ -258,6 +258,9 @@ def is_loggable(self):
     def is_defined(self):
         return self._default_value is not Undefined
 
+    def is_alias(self):
+        return self._target is not None
+
     def undefine(self):
         self._default_value = Undefined
 
@@ -267,14 +270,14 @@ def define(self, value):
 
     @property
     def _default_value(self):
-        if self._target:
+        if self.is_alias():
             return self._target._default_value
         else:
             return self._p_default_value
 
     @_default_value.setter
     def _default_value(self, value):
-        if self._target:
+        if self.is_alias():
             self._target._default_value = value
         else:
             self._p_default_value = value
@@ -305,6 +308,18 @@ def field(self):
     def name(self):
         return self._name
 
+    @property
+    def target(self):
+        return self._target
+
+    def reset_target(self, new_target):
+        if not self.is_deprecated():
+            self._p_field = new_target._field
+        else:
+            self._p_field._target_field = new_target._field
+
+        self._target = new_target
+
     def __set_name__(self, owner, name):
         self._name = name
 
@@ -687,6 +702,9 @@ def __init__(self, other):
 
         self._warn_deprecation(DEPRECATE_RD)
 
+    def __repr__(self):
+        return super().__repr__().replace('TestVar', 'ShadowVar')
+
 
 class VarSpace(namespaces.Namespace):
     '''Variable space of a regression test.
@@ -724,6 +742,12 @@ def join(self, other, cls):
 
             self.vars[key] = copy.deepcopy(var)
 
+        # Inherited variables are copied in the current namespace, so we need
+        # to update any aliases to point to the current namespace copies
+        for var in self.vars.values():
+            if var.is_alias():
+                var.reset_target(self.vars[var.target.name])
+
         # Carry over the set of injected variables
         self._injected_vars.update(other._injected_vars)
 
diff --git a/unittests/test_pipeline.py b/unittests/test_pipeline.py
index 0d6a8350cc..b21b354eb7 100644
--- a/unittests/test_pipeline.py
+++ b/unittests/test_pipeline.py
@@ -1892,16 +1892,15 @@ def set_defaults(self):
     assert x.bar == 100
 
 
-def _test_variables_deprecation():
+def test_variables_deprecation():
     with pytest.warns(ReframeDeprecationWarning):
         class _X(rfm.RunOnlyRegressionTest):
             variables = {'FOO': 1}
 
     test = _X()
-    print('===')
     assert test.env_vars['FOO'] == 1
 
     with pytest.warns(ReframeDeprecationWarning):
-        test.variables['BAR'] == 2
+        test.variables['BAR'] = 2
 
     assert test.env_vars['BAR'] == 2