Updating and extending utility functions

Author: svorenova

unit/testing-utils/require_goto_statements.cpp

@@ -11,6 +11,8 @@
 
 #include <algorithm>
 #include <util/expr_iterator.h>
+#include <goto-programs/goto_functions.h>
+#include <java_bytecode/java_types.h>
 
 /// Expand value of a function to include all child codets
 /// \param function_value: The value of the function (e.g. got by looking up
@@ -33,18 +35,38 @@ require_goto_statements::get_all_statements(const exprt &function_value)
   return statements;
 }
 
-/// Find assignment statements of the form \p structure_name.\component_name =
+/// \param symbol_table Symbol table for the test
+/// \return All codet statements of the __CPROVER_start function
+const std::vector<codet>
+require_goto_statements::require_entry_point_statements(
+  const symbol_tablet &symbol_table)
+{
+  // Retrieve __CPROVER_start
+  const symbolt *entry_point_function =
+    symbol_table.lookup(goto_functionst::entry_point());
+  REQUIRE(entry_point_function != nullptr);
+  return get_all_statements(entry_point_function->value);
+}
+
+/// Find assignment statements of the form:
+/// - \p structure_name
+/// .@\p superclass_name.\p component_name = (if it's a component inherited
+/// from the superclass)
+/// - \p structure_name.\p component_name = (otherwise)
 /// \param statements: The statements to look through
 /// \param structure_name: The name of variable of type struct
-/// \param component_name: The name of the component that should be assigned
+/// \param superclass_name: The name of the superclass (if given)
+/// \param component_name: The name of the component of the superclass that
+/// should be assigned
 /// \return: All the assignments to that component.
-std::vector<code_assignt>
+require_goto_statements::pointer_assignment_locationt
 require_goto_statements::find_struct_component_assignments(
   const std::vector<codet> &statements,
   const irep_idt &structure_name,
+  const optionalt<irep_idt> &superclass_name,
   const irep_idt &component_name)
 {
-  std::vector<code_assignt> component_assignments;
+  pointer_assignment_locationt locations;
 
   for(const auto &assignment : statements)
   {
@@ -54,19 +76,69 @@ require_goto_statements::find_struct_component_assignments(
 
       if(code_assign.lhs().id() == ID_member)
       {
-        const auto &member_expr = to_member_expr(code_assign.lhs());
-        const auto &symbol = member_expr.symbol();
+        const member_exprt &member_expr = to_member_expr(code_assign.lhs());
 
-        if(
-          symbol.get_identifier() == structure_name &&
-          member_expr.get_component_name() == component_name)
+        if(superclass_name.has_value())
         {
-          component_assignments.push_back(code_assign);
+          // Structure of the expression:
+          // member_exprt member_expr:
+          // - component name: \p component_name
+          // - operand (component of): member_exprt superclass_expr:
+          //     - component name: @\p superclass_name
+          //     - operand (component of): symbol for \p structure_name
+          if(
+            member_expr.get_component_name() == component_name &&
+            member_expr.compound().id() == ID_member)
+          {
+            const member_exprt &superclass_expr =
+              to_member_expr(member_expr.op0());
+            const irep_idt supercomponent_name =
+              "@" + id2string(superclass_name.value());
+
+            if(
+              superclass_expr.get_component_name() == supercomponent_name &&
+              superclass_expr.symbol().get_identifier() == structure_name)
+            {
+              if(
+                code_assign.rhs() ==
+                null_pointer_exprt(to_pointer_type(code_assign.lhs().type())))
+              {
+                locations.null_assignment = code_assign;
+              }
+              else
+              {
+                locations.non_null_assignments.push_back(code_assign);
+              }
+            }
+          }
+        }
+        else
+        {
+          // Structure of the expression:
+          // member_exprt member_expr:
+          // - component name: \p component_name
+          // - operand (component of): symbol for \p structure_name
+          if(
+            member_expr.op().id() == ID_symbol &&
+            member_expr.symbol().get_identifier() == structure_name &&
+            member_expr.get_component_name() == component_name)
+          {
+            if(
+              code_assign.rhs() ==
+              null_pointer_exprt(to_pointer_type(code_assign.lhs().type())))
+            {
+              locations.null_assignment = code_assign;
+            }
+            else
+            {
+              locations.non_null_assignments.push_back(code_assign);
+            }
+          }
         }
       }
     }
   }
-  return component_assignments;
+  return locations;
 }
 
 /// For a given variable name, gets the assignments to it in the provided
@@ -131,3 +203,195 @@ const code_declt &require_goto_statements::require_declaration_of_name(
   }
   throw no_decl_found_exceptiont(variable_name.c_str());
 }
+
+/// Checks that the component of the structure (possibly inherited from
+/// the superclass) is assigned an object of the given type.
+/// \param structure_name The name the variable
+/// \param superclass_name The name of its superclass (if given)
+/// \param component_name The name of the field of the superclass
+/// \param component_type_name The name of the required type of the field
+/// \param typecast_name The name of the type to which the object is cast (if
+/// there is a typecast)
+/// \param entry_point_instructions The statements to look through
+/// \return The identifier of the variable assigned to the field
+const irep_idt &require_goto_statements::require_struct_component_assignment(
+  const irep_idt &structure_name,
+  const optionalt<irep_idt> &superclass_name,
+  const irep_idt &component_name,
+  const irep_idt &component_type_name,
+  const optionalt<irep_idt> &typecast_name,
+  const std::vector<codet> &entry_point_instructions)
+{
+  // First we need to find the assignments to the component belonging to
+  // the structure_name object
+  const auto &component_assignments =
+    require_goto_statements::find_struct_component_assignments(
+      entry_point_instructions,
+      structure_name,
+      superclass_name,
+      component_name);
+  REQUIRE(component_assignments.non_null_assignments.size() == 1);
+
+  // We are expecting that the resulting statement can be of two forms:
+  // 1. structure_name.(@superclass_name if given).component =
+  //     (struct cast_type_name *) tmp_object_factory$1;
+  //   followed by a direct assignment like this:
+  //     tmp_object_factory$1 = &tmp_object_factory$2;
+  // 2. structure_name.component = &tmp_object_factory$1;
+  exprt component_assignment_rhs_expr =
+    component_assignments.non_null_assignments[0].rhs();
+
+  // If the rhs is a typecast (case 1 above), deconstruct it to get the name of
+  // the variable and find the assignment to it
+  if(component_assignment_rhs_expr.id() == ID_typecast)
+  {
+    const auto &component_assignment_rhs =
+      to_typecast_expr(component_assignment_rhs_expr);
+
+    // Check the type we are casting to
+    if(typecast_name.has_value())
+    {
+      REQUIRE(component_assignment_rhs.type().id() == ID_pointer);
+      REQUIRE(
+        to_symbol_type(
+          to_pointer_type(component_assignment_rhs.type()).subtype())
+          .get(ID_identifier) == typecast_name.value());
+    }
+
+    const auto &component_reference_tmp_name =
+      to_symbol_expr(component_assignment_rhs.op()).get_identifier();
+    const auto &component_reference_assignments =
+      require_goto_statements::find_pointer_assignments(
+        component_reference_tmp_name, entry_point_instructions)
+        .non_null_assignments;
+    REQUIRE(component_reference_assignments.size() == 1);
+    component_assignment_rhs_expr = component_reference_assignments[0].rhs();
+  }
+
+  // The rhs assigns an address of a variable, get its name
+  const auto &component_reference_assignment_rhs =
+    to_address_of_expr(component_assignment_rhs_expr);
+  const auto &component_tmp_name =
+    to_symbol_expr(component_reference_assignment_rhs.op()).get_identifier();
+
+  // After we have found the declaration of the final assignment's
+  // right hand side, then we want to identify that the type
+  // is the one we expect, e.g.:
+  // struct java.lang.Integer { __CPROVER_string @class_identifier;
+  // boolean @lock; } tmp_object_factory$2;
+  const auto &component_declaration =
+    require_goto_statements::require_declaration_of_name(
+      component_tmp_name, entry_point_instructions);
+  REQUIRE(component_declaration.symbol().type().id() == ID_struct);
+  const auto &component_struct =
+    to_struct_type(component_declaration.symbol().type());
+  REQUIRE(component_struct.get(ID_name) == component_type_name);
+
+  return component_tmp_name;
+}
+
+/// Checks that the array component of the structure (possibly inherited from
+/// the superclass) is assigned an array with given element type.
+/// \param structure_name The name the variable
+/// \param superclass_name The name of its superclass (if given)
+/// \param array_component_name The name of the array field of the superclass
+/// \param array_type_name The type of the array, e.g., java::array[reference]
+/// \param array_component_element_type_name The element type of the array
+/// \param entry_point_instructions The statements to look through
+/// \return The identifier of the variable assigned to the field
+const irep_idt &
+require_goto_statements::require_struct_array_component_assignment(
+  const irep_idt &structure_name,
+  const optionalt<irep_idt> &superclass_name,
+  const irep_idt &array_component_name,
+  const irep_idt &array_type_name,
+  const irep_idt &array_component_element_type_name,
+  const std::vector<codet> &entry_point_instructions)
+{
+  // First we need to find the assignments to the component belonging to
+  // the structure_name object
+  const auto &component_assignments =
+    require_goto_statements::find_struct_component_assignments(
+      entry_point_instructions,
+      structure_name,
+      superclass_name,
+      array_component_name);
+  REQUIRE(component_assignments.non_null_assignments.size() == 1);
+
+  // We are expecting that the resulting statement is of form:
+  // structure_name.array_component_name = (struct array_type_name *)
+  //    tmp_object_factory$1;
+  const exprt &component_assignment_rhs_expr =
+    component_assignments.non_null_assignments[0].rhs();
+
+  // The rhs is a typecast, deconstruct it to get the name of the variable
+  // and find the assignment to it
+  PRECONDITION(component_assignment_rhs_expr.id() == ID_typecast);
+  const auto &component_assignment_rhs =
+    to_typecast_expr(component_assignment_rhs_expr);
+  const auto &component_reference_tmp_name =
+    to_symbol_expr(component_assignment_rhs.op()).get_identifier();
+
+  // Check the type we are casting to matches the array type
+  REQUIRE(component_assignment_rhs.type().id() == ID_pointer);
+  REQUIRE(
+    to_symbol_type(to_pointer_type(component_assignment_rhs.type()).subtype())
+      .get(ID_identifier) == array_type_name);
+
+  // Get the tmp_object name and find assignments to it, there should be only
+  // one that assigns the correct array through side effect
+  const auto &component_reference_assignments =
+    require_goto_statements::find_pointer_assignments(
+      component_reference_tmp_name, entry_point_instructions);
+  REQUIRE(component_reference_assignments.non_null_assignments.size() == 1);
+  const exprt &component_reference_assignment_rhs_expr =
+    component_reference_assignments.non_null_assignments[0].rhs();
+
+  // The rhs is side effect
+  PRECONDITION(component_reference_assignment_rhs_expr.id() == ID_side_effect);
+  const auto &array_component_reference_assignment_rhs =
+    to_side_effect_expr(component_reference_assignment_rhs_expr);
+
+  // The type of the side effect is an array with the correct element type
+  PRECONDITION(
+    array_component_reference_assignment_rhs.type().id() == ID_pointer);
+  const typet &array =
+    to_pointer_type(array_component_reference_assignment_rhs.type()).subtype();
+  PRECONDITION(is_java_array_tag(array.get(ID_identifier)));
+  REQUIRE(array.get(ID_identifier) == array_type_name);
+
+  return component_reference_tmp_name;
+}
+
+/// Checks that the input argument (of method under test) with given name is
+/// assigned a single non-null object in the entry point function.
+/// \param argument_name Name of the input argument of method under test
+/// \param entry_point_statements The statements to look through
+/// \return The identifier of the variable assigned to the input argument
+const irep_idt &
+require_goto_statements::require_entry_point_argument_assignment(
+  const irep_idt &argument_name,
+  const std::vector<codet> &entry_point_statements)
+{
+  // Trace the creation of the object that is being supplied as the input
+  // argument to the function under test
+  const pointer_assignment_locationt &argument_assignments =
+    find_pointer_assignments(
+      id2string(goto_functionst::entry_point()) + "::" +
+        id2string(argument_name),
+      entry_point_statements);
+
+  // There should be at most one assignment to it
+  REQUIRE(argument_assignments.non_null_assignments.size() == 1);
+
+  // The following finds the name of the tmp object that gets assigned
+  // to the input argument. There must be one such assignment only,
+  // and usually looks like this:
+  //   argument_name = &tmp_object_factory$1;
+  const auto &argument_assignment =
+    argument_assignments.non_null_assignments[0];
+  const auto &argument_tmp_name =
+    to_symbol_expr(to_address_of_expr(argument_assignment.rhs()).object())
+      .get_identifier();
+  return argument_tmp_name;
+}

unit/testing-utils/require_goto_statements.h

@@ -47,20 +47,44 @@ class no_decl_found_exceptiont : public std::exception
   std::string _varname;
 };
 
-std::vector<code_assignt> find_struct_component_assignments(
+pointer_assignment_locationt find_struct_component_assignments(
   const std::vector<codet> &statements,
   const irep_idt &structure_name,
+  const optionalt<irep_idt> &superclass_name,
   const irep_idt &component_name);
 
 std::vector<codet> get_all_statements(const exprt &function_value);
 
+const std::vector<codet>
+require_entry_point_statements(const symbol_tablet &symbol_table);
+
 pointer_assignment_locationt find_pointer_assignments(
   const irep_idt &pointer_name,
   const std::vector<codet> &instructions);
 
 const code_declt &require_declaration_of_name(
   const irep_idt &variable_name,
   const std::vector<codet> &entry_point_instructions);
+
+const irep_idt &require_struct_component_assignment(
+  const irep_idt &structure_name,
+  const optionalt<irep_idt> &superclass_name,
+  const irep_idt &component_name,
+  const irep_idt &component_type_name,
+  const optionalt<irep_idt> &typecast_name,
+  const std::vector<codet> &entry_point_instructions);
+
+const irep_idt &require_struct_array_component_assignment(
+  const irep_idt &structure_name,
+  const optionalt<irep_idt> &superclass_name,
+  const irep_idt &array_component_name,
+  const irep_idt &array_type_name,
+  const irep_idt &array_component_element_type_name,
+  const std::vector<codet> &entry_point_instructions);
+
+const irep_idt &require_entry_point_argument_assignment(
+  const irep_idt &argument_name,
+  const std::vector<codet> &entry_point_statements);
 }
 
 #endif // CPROVER_TESTING_UTILS_REQUIRE_GOTO_STATEMENTS_H