Merge pull request diffblue#389 from diffblue/bugfix/include_statics_in_func_summary

[SEC-209] Initialise new globals in function summaries

Author: JohnDumbell

regression/LVSA/TestEVS/Test$A.class

@@ -78,19 +78,16 @@ public void call_overridden_method_on_A(A a) {
   }
 
   public void apply_call_overridden_method_on_A_with_A() {
-    Node n = static_node; // workaround for SEC-209
     A a = new A();
     call_overridden_method_on_A(a);
   }
 
   public void apply_call_overridden_method_on_A_with_B() {
-    Node n = static_node; // workaround for SEC-209
     B b = new B();
     call_overridden_method_on_A(b);
   }
 
   public void apply_call_overridden_method_on_A_with_C() {
-    Node n = static_node; // workaround for SEC-209
     C c = new C();
     call_overridden_method_on_A(c);
   }
@@ -119,20 +116,17 @@ public static void function_with_B_parameter(B b) {
   }
 
   public void call_function_with_B_parameter_with_C_argument(C c) {
-    Object o = static_object; // workaround for SEC-209
     Test.function_with_B_parameter(c);
   }
 
   public void call_function_with_B_parameter_with_A_argument_cast_to_C(A a) {
-    Object o = static_object; // workaround for SEC-209
     if (a instanceof C) {
       Test.function_with_B_parameter((C)a);
     }
   }
 
   public void
   apply_call_function_with_B_parameter_with_A_argument_cast_to_C_with_C(C c) {
-    Object o = static_object; // workaround for SEC-209
     c.extra_object = new Object();
     call_function_with_B_parameter_with_A_argument_cast_to_C(c);
   }
@@ -173,7 +167,6 @@ public void function_which_sets_static_variable() {
   }
 
   public void apply_function_which_sets_static_variable() {
-    Object o = static_object; // workaround for SEC-209
     function_which_sets_static_variable();
   }
 
@@ -184,7 +177,6 @@ public void function_which_may_set_static_variable(Boolean b) {
   }
 
   public void apply_function_which_may_set_static_variable(Boolean b) {
-    Object o = static_object; // workaround for SEC-209
     function_which_may_set_static_variable(b);
   }
 }

regression/LVSA/TestEVS/Test$B.class

@@ -27,8 +27,10 @@ def test_outputs_dynamic_object(tmpdir):
 
     value_set_expectation = lvsa_expectation.get_value_set_for_output()
 
-    value_set_expectation.check_number_of_values(1)
+    value_set_expectation.check_number_of_values(2)
     value_set_expectation.check_contains_dynamic_object()
+    value_set_expectation.check_contains_root_object_evs(
+        label_suffix='java::LVSA.TestEscapeAnalysis.Test.output')
 
 
 def test_dynamic_object_assigned_to_field_of_parameter(tmpdir):

regression/LVSA/TestEVS/Test$C.class

@@ -22,9 +22,11 @@ def test_apply_field_setter(tmpdir):
 
     value_set_expectation = lvsa_expectation.get_value_set_for_output()
 
-    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='java::LVSA.TestPreciseAccessPaths.Test.static_object')
+    value_set_expectation.check_contains_root_object_evs(
+        label_suffix='java::LVSA.TestPreciseAccessPaths.Test.output')
 
 
 def test_field_getter(tmpdir):
@@ -212,8 +214,10 @@ def test_apply_get_list_node(tmpdir):
 
     value_set_expectation = lvsa_expectation.get_value_set_for_output()
 
-    value_set_expectation.check_number_of_values(1)
+    value_set_expectation.check_number_of_values(2)
     value_set_expectation.check_contains_per_field_evs(access_path=['.data'])
+    value_set_expectation.check_contains_root_object_evs(
+        label_suffix='java::LVSA.TestPreciseAccessPaths.Test.output')
 
 
 def test_two_field_derefs(tmpdir):

regression/LVSA/TestEVS/Test$Node.class

@@ -62,26 +62,21 @@ static void gather_external_symbols(
     gather_external_symbols(it->code, ns, result);
 }
 
-void local_value_set_analysist::initialize(const goto_programt &fun)
+/// Adds default external value set entries for all external symbols
+/// to the passed-in local value set.
+/// \param external_symbols: vector of external symbols to add
+/// \param ns: namespace for the code under analysis
+/// \param value_set: value set that the default entires should be put into
+static void add_default_evses(
+  std::vector<symbol_exprt> &external_symbols,
+  const namespacet &ns,
+  local_value_sett &value_set)
 {
-  baset::initialize(fun);
-
-  if(fun.instructions.empty())
-    return;
-
-  std::vector<symbol_exprt> external_symbols;
-
-  for(const auto &param : function_type.parameters())
-    external_symbols.emplace_back(param.get_identifier(), param.type());
-
-  gather_external_symbols(fun, ns, external_symbols);
-
   std::sort(external_symbols.begin(), external_symbols.end());
   external_symbols.erase(
     std::unique(external_symbols.begin(), external_symbols.end()),
     external_symbols.end());
 
-  auto &initial_state = (*this)[fun.instructions.begin()].value_set;
   const external_value_set_typet default_mode_for_new_evs =
     external_value_set_typet::ROOT_OBJECT;
 
@@ -99,13 +94,32 @@ void local_value_set_analysist::initialize(const goto_programt &fun)
         false);
       local_value_sett::entryt extsym_entry_blank(
         id2string(extsym_name), "", typet(), extsym_var);
-      auto &extsym_entry = initial_state.get_entry(
-        extsym_entry_blank, extsym.type().subtype(), ns);
-      initial_state.insert(extsym_entry.object_map, extsym_var);
+      auto &extsym_entry =
+        value_set.get_entry(extsym_entry_blank, extsym.type().subtype(), ns);
+      value_set.insert(extsym_entry.object_map, extsym_var);
     }
   }
 }
 
+void local_value_set_analysist::initialize(const goto_programt &fun)
+{
+  baset::initialize(fun);
+
+  if(fun.instructions.empty())
+    return;
+
+  std::vector<symbol_exprt> external_symbols;
+
+  for(const auto &param : function_type.parameters())
+    external_symbols.emplace_back(param.get_identifier(), param.type());
+
+  gather_external_symbols(fun, ns, external_symbols);
+
+  auto &initial_state = (*this)[fun.instructions.begin()].value_set;
+
+  add_default_evses(external_symbols, ns, initial_state);
+}
+
 /// Collects all value-set entries that match a given field name, and optionally
 /// a type. For example, `get_all_field_value_sets("x", typet(), ...)` would
 /// get all entries concerning an "x" field, whereas
@@ -365,6 +379,33 @@ void local_value_set_analysist::transform_function_stub(
   // Thus start by reading all RHS values, before any changes are made:
 
   auto &valuesets = static_cast<domaint &>(state).value_set;
+
+  // We need to find all potential static / global variables and initalize
+  // them with default values.
+  std::vector<symbol_exprt> external_symbols;
+  for(const auto &assignment : assignments)
+  {
+    const auto &lhs = assignment.first;
+    if(lhs.structured_lhs.id() == ID_external_value_set)
+    {
+      const symbolt *ext_sym;
+      if(!ns.lookup(lhs.base_name, ext_sym) && ext_sym->is_static_lifetime)
+      {
+        symbol_exprt sym_expr = ext_sym->symbol_expr();
+        const auto &sym_identifier = id2string(sym_expr.get_identifier());
+        if(!has_suffix(sym_identifier, RETURN_VALUE_SUFFIX))
+        {
+          external_symbols.push_back(sym_expr);
+        }
+      }
+    }
+  }
+
+  if(!external_symbols.empty())
+  {
+    add_default_evses(external_symbols, ns, valuesets);
+  }
+
   std::map<exprt, local_value_sett::object_mapt> pre_call_rhs_value_sets;
 
   for(const auto &assignment : assignments)