[TG-496] Add Goto function unit test utilities

unit/testing-utils/Makefile

@@ -2,6 +2,8 @@ SRC = \
   c_to_expr.cpp \
   load_java_class.cpp \
   require_expr.cpp \
+  require_goto_statements.cpp \
+  require_symbol.cpp \
   require_type.cpp \
   # Empty last line (please keep above list sorted!)
 

unit/testing-utils/load_java_class.cpp

@@ -26,6 +26,15 @@
 symbol_tablet load_java_class(
   const std::string &java_class_name,
   const std::string &class_path)
+{
+  return load_java_class(
+    java_class_name, class_path, new_java_bytecode_language());
+}
+
+symbol_tablet load_java_class(
+  const std::string &java_class_name,
+  const std::string &class_path,
+  std::unique_ptr<languaget> java_lang)
 {
   // We don't expect the .class suffix to allow us to check the name of the
   // class
@@ -39,8 +48,6 @@ symbol_tablet load_java_class(
 
   symbol_tablet new_symbol_table;
 
-  std::unique_ptr<languaget>java_lang(new_java_bytecode_language());
-
   std::istringstream java_code_stream("ignored");
   null_message_handlert message_handler;
 

unit/testing-utils/load_java_class.h

@@ -14,9 +14,16 @@
 #define CPROVER_TESTING_UTILS_LOAD_JAVA_CLASS_H
 
 #include <util/symbol_table.h>
+#include <util/language.h>
+#include <goto-programs/goto_model.h>
 
 symbol_tablet load_java_class(
   const std::string &java_class_name,
   const std::string &class_path);
 
+symbol_tablet load_java_class(
+  const std::string &java_class_name,
+  const std::string &class_path,
+  std::unique_ptr<languaget> java_lang);
+
 #endif // CPROVER_TESTING_UTILS_LOAD_JAVA_CLASS_H

unit/testing-utils/require_goto_statements.cpp

@@ -0,0 +1,133 @@
+/*******************************************************************\
+
+ Module: Unit test utilities
+
+ Author: DiffBlue Limited. All rights reserved.
+
+\*******************************************************************/
+
+#include "require_goto_statements.h"
+#include "catch.hpp"
+
+#include <algorithm>
+#include <util/expr_iterator.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
+///  the function in the symbol table and getting the value)
+/// \return: All ID_code statements in the tree rooted at \p function_value
+std::vector<codet>
+require_goto_statements::get_all_statements(const exprt &function_value)
+{
+  std::vector<codet> statements;
+  for(auto sub_expression_it = function_value.depth_begin();
+      sub_expression_it != function_value.depth_end();
+      ++sub_expression_it)
+  {
+    if(sub_expression_it->id() == ID_code)
+    {
+      statements.push_back(to_code(*sub_expression_it));
+    }
+  }
+
+  return statements;
+}
+
+/// Find assignment statements of the form \p structure_name.\component_name =
+/// \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
+/// \return: All the assignments to that component.
+std::vector<code_assignt>
+require_goto_statements::find_struct_component_assignments(
+  const std::vector<codet> &statements,
+  const irep_idt &structure_name,
+  const irep_idt &component_name)
+{
+  std::vector<code_assignt> component_assignments;
+
+  for(const auto &assignment : statements)
+  {
+    if(assignment.get_statement() == ID_assign)
+    {
+      const code_assignt &code_assign = to_code_assign(assignment);
+
+      if(code_assign.lhs().id() == ID_member)
+      {
+        const auto &member_expr = to_member_expr(code_assign.lhs());
+        const auto &symbol = member_expr.symbol();
+
+        if(
+          symbol.get_identifier() == structure_name &&
+          member_expr.get_component_name() == component_name)
+        {
+          component_assignments.push_back(code_assign);
+        }
+      }
+    }
+  }
+  return component_assignments;
+}
+
+/// For a given variable name, gets the assignments to it in the provided
+/// instructions.
+/// \param pointer_name: The name of the variable
+/// \param instructions: The instructions to look through
+/// \return: A structure that contains the null assignment if found, and a
+/// vector of all other assignments
+require_goto_statements::pointer_assignment_locationt
+require_goto_statements::find_pointer_assignments(
+  const irep_idt &pointer_name,
+  const std::vector<codet> &instructions)
+{
+  pointer_assignment_locationt locations;
+  for(const codet &statement : instructions)
+  {
+    if(statement.get_statement() == ID_assign)
+    {
+      const code_assignt &code_assign = to_code_assign(statement);
+      if(
+        code_assign.lhs().id() == ID_symbol &&
+        to_symbol_expr(code_assign.lhs()).get_identifier() == pointer_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 locations;
+}
+
+/// Find the declaration of the specific variable.
+/// \param variable_name: The name of the variable.
+/// \param entry_point_instructions: The statements to look through
+/// \return The declaration statement corresponding to that variable
+/// \throws no_decl_found_exceptiont if no declaration of the specific
+/// variable is found
+const code_declt &require_goto_statements::require_declaration_of_name(
+  const irep_idt &variable_name,
+  const std::vector<codet> &entry_point_instructions)
+{
+  for(const auto &statement : entry_point_instructions)
+  {
+    if(statement.get_statement() == ID_decl)
+    {
+      const auto &decl_statement = to_code_decl(statement);
+
+      if(decl_statement.get_identifier() == variable_name)
+      {
+        return decl_statement;
+      }
+    }
+  }
+  throw no_decl_found_exceptiont(variable_name.c_str());
+}

unit/testing-utils/require_goto_statements.h

@@ -0,0 +1,66 @@
+/*******************************************************************\
+
+ Module: Unit test utilities
+
+ Author: DiffBlue Limited. All rights reserved.
+
+\*******************************************************************/
+
+/// \file
+/// Utilties for inspecting goto functions
+
+#include <util/irep.h>
+#include <util/expr.h>
+#include <util/optional.h>
+#include <util/std_code.h>
+#include <util/std_types.h>
+#include <goto-programs/goto_program.h>
+
+#ifndef CPROVER_TESTING_UTILS_REQUIRE_GOTO_STATEMENTS_H
+#define CPROVER_TESTING_UTILS_REQUIRE_GOTO_STATEMENTS_H
+
+// NOLINTNEXTLINE(readability/namespace)
+namespace require_goto_statements
+{
+struct pointer_assignment_locationt
+{
+  optionalt<code_assignt> null_assignment;
+  std::vector<code_assignt> non_null_assignments;
+};
+
+class no_decl_found_exceptiont : public std::exception
+{
+public:
+  explicit no_decl_found_exceptiont(const std::string &var_name)
+    : _varname(var_name)
+  {
+  }
+
+  virtual const char *what() const throw()
+  {
+    std::ostringstream stringStream;
+    stringStream << "Failed to find declaration for: " << _varname;
+    return stringStream.str().c_str();
+  }
+
+private:
+  std::string _varname;
+};
+
+std::vector<code_assignt> find_struct_component_assignments(
+  const std::vector<codet> &statements,
+  const irep_idt &structure_name,
+  const irep_idt &component_name);
+
+std::vector<codet> get_all_statements(const exprt &function_value);
+
+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);
+}
+
+#endif // CPROVER_TESTING_UTILS_REQUIRE_GOTO_STATEMENTS_H