Put interface to cover_blocks in virtual class

This will allow to have two implementations for this functor.

Author: romainbrenguier

src/goto-instrument/cover_basic_blocks.h

@@ -18,44 +18,88 @@ Author: Daniel Kroening
 
 class message_handlert;
 
-class cover_basic_blockst final
+class cover_blocks_baset
+{
+public:
+  /// \param t a goto instruction
+  /// \return the block number of the block
+  ///         the given goto instruction is part of
+  virtual std::size_t block_of(goto_programt::const_targett t) const = 0;
+
+  /// \param block_nr a block number
+  /// \return  the instruction selected for
+  ///   instrumentation representative of the given block
+  virtual optionalt<goto_programt::const_targett>
+  instruction_of(std::size_t block_nr) const = 0;
+
+  /// \param block_nr a block number
+  /// \return  the source location selected for
+  ///   instrumentation representative of the given block
+  virtual const source_locationt &
+  source_location_of(std::size_t block_nr) const = 0;
+
+  /// Select an instruction to be instrumented for each basic block such that
+  /// the java bytecode indices for each basic block is unique
+  /// \param goto_program The goto program
+  /// \param message_handler The message handler
+  virtual void select_unique_java_bytecode_indices(
+    const goto_programt &goto_program,
+    message_handlert &message_handler)
+  {
+  }
+
+  /// Outputs the list of blocks
+  virtual void output(std::ostream &out) const = 0;
+
+  /// Output warnings about ignored blocks
+  /// \param goto_program The goto program
+  /// \param message_handler The message handler
+  virtual void report_block_anomalies(
+    const goto_programt &goto_program,
+    message_handlert &message_handler)
+  {
+  }
+};
+
+class cover_basic_blockst final : public cover_blocks_baset
 {
 public:
   explicit cover_basic_blockst(const goto_programt &_goto_program);
 
   /// \param t a goto instruction
   /// \return the block number of the block
   ///         the given goto instruction is part of
-  std::size_t block_of(goto_programt::const_targett t) const;
+  std::size_t block_of(goto_programt::const_targett t) const override;
 
   /// \param block_nr a block number
   /// \return  the instruction selected for
   ///   instrumentation representative of the given block
   optionalt<goto_programt::const_targett>
-  instruction_of(std::size_t block_nr) const;
+  instruction_of(std::size_t block_nr) const override;
 
   /// \param block_nr a block number
   /// \return  the source location selected for
   ///   instrumentation representative of the given block
-  const source_locationt &source_location_of(std::size_t block_nr) const;
+  const source_locationt &
+  source_location_of(std::size_t block_nr) const override;
 
   /// Select an instruction to be instrumented for each basic block such that
   /// the java bytecode indices for each basic block is unique
   /// \param goto_program The goto program
   /// \param message_handler The message handler
   void select_unique_java_bytecode_indices(
     const goto_programt &goto_program,
-    message_handlert &message_handler);
+    message_handlert &message_handler) override;
 
   /// Output warnings about ignored blocks
   /// \param goto_program The goto program
   /// \param message_handler The message handler
   void report_block_anomalies(
     const goto_programt &goto_program,
-    message_handlert &message_handler);
+    message_handlert &message_handler) override;
 
   /// Outputs the list of blocks
-  void output(std::ostream &out) const;
+  void output(std::ostream &out) const override;
 
 private:
   typedef std::map<goto_programt::const_targett, std::size_t> block_mapt;