Merge pull request diffblue#329 from diffblue/owen-jones-diffblue/precise-evs-weak-writes-in-function-summary

Turn off strong writes for precise EVSs

Author: owen-jones-diffblue

regression/LVSA/TestEVS/test_evs.py

@@ -70,7 +70,8 @@ def test_read_from_field_from_supertype(tmpdir):
 
     value_set_expectation.check_number_of_values(2)
     value_set_expectation.check_contains_per_field_evs(access_path=['.left'])
-    value_set_expectation.check_contains_precise_evs(access_path=['[email protected]$A.node', '.left'])
+    value_set_expectation.check_contains_precise_evs(label_suffix='b', access_path=['[email protected]$A.node',
+                                                                                '.left'])
 
 
 def test_write_to_field_from_supertype(tmpdir):
@@ -91,9 +92,10 @@ def test_write_to_field_of_B_through_A(tmpdir):
 
     value_set_expectation = lvsa_expectation.get_value_set_for_public_static('static_node')
 
-    value_set_expectation.check_number_of_values(2)
+    value_set_expectation.check_number_of_values(3)
     value_set_expectation.check_contains_root_object_evs(label_suffix='node_parameter')
     value_set_expectation.check_contains_per_field_evs(access_path=['.node'])
+    value_set_expectation.check_contains_precise_evs(label_suffix='b', access_path=['[email protected]$A.node'])
 
 
 def test_read_from_array(tmpdir):

regression/LVSA/TestPreciseAccessPaths/test_precise_access_paths.py

@@ -66,8 +66,10 @@ def test_apply_set_field_of_external_object(tmpdir):
     value_set_expectation = lvsa_expectation.get_value_set_for_precise_evs(
         parameter_name='parameter_a', suffix='.object')
 
-    value_set_expectation.check_number_of_values(1)
+    value_set_expectation.check_number_of_values(2)
     value_set_expectation.check_contains_root_object_evs(label_suffix='parameter_object')
+    value_set_expectation.check_contains_precise_evs(label_suffix='parameter_a', access_path=['.object'],
+                                                     is_initializer=True)
 
 
 def test_conditionally_set_field_of_external_object(tmpdir):
@@ -88,8 +90,10 @@ def test_apply_conditionally_set_field_of_external_object(tmpdir):
     value_set_expectation = lvsa_expectation.get_value_set_for_precise_evs(
         parameter_name='parameter_a', suffix='.object')
 
-    value_set_expectation.check_number_of_values(1)
+    value_set_expectation.check_number_of_values(2)
     value_set_expectation.check_contains_root_object_evs(label_suffix='parameter_object')
+    value_set_expectation.check_contains_precise_evs(label_suffix='parameter_a', access_path=['.object'],
+                                                     is_initializer=True)
 
 
 def test_read_field_before_writing_to_aliasable_field(tmpdir):
@@ -168,8 +172,9 @@ def test_call_function_to_allocate_new_object(tmpdir):
 
     value_set_expectation = lvsa_expectation.get_value_set_for_output()
 
-    value_set_expectation.check_number_of_values(2)
+    value_set_expectation.check_number_of_values(3)
     value_set_expectation.check_contains_per_field_evs(access_path=['.object'])
+    value_set_expectation.check_contains_precise_evs(label_suffix='param_A', access_path=['.object'])
     value_set_expectation.check_contains_dynamic_object()
 
 

src/pointer-analysis/local_value_set_analysis.cpp

@@ -462,15 +462,9 @@ void local_value_set_analysist::transform_function_stub(
         ns,
         *this);
 
-      std::string objkey = lhs_fieldname.base_name + lhs_fieldname.field_name;
-      auto it = valuesets.values.find(objkey);
-      const bool singular = it == valuesets.values.end() ||
-                            it->second.object_map.read().size() == 1;
-      bool add_to_sets =
-        !singular ||
-        !precise_evs.can_make_strong_write_to_precise_external_value_set();
-
-      auto demoted_rhs_values = pre_call_rhs_value_sets.at(assignment.second);
+      /// Weak write - can we do strong writes?
+      bool add_to_sets = true;
+      auto demoted_rhs_values=pre_call_rhs_value_sets.at(assignment.second);
       valuesets.demote_initializers(demoted_rhs_values);
       valuesets.assign_valueset(
         precise_access_path_expr, demoted_rhs_values, ns, add_to_sets);