[libxml++] Validators: Change which methods are virtual, add override

[Kjell Ahlstedt <kjellahl src gnome org>]

commit 31716dcae4acfdd9e85e1076e084f277eef2f554
Author: Kjell Ahlstedt <kjell ahlstedt bredband net>
Date:   Thu Sep 24 09:55:55 2015 +0200

    Validators: Change which methods are virtual, add override
    
    * libxml++/validators/validator.h: Add some pure virtual methods.
    * libxml++/validators/dtdvalidator.[h|cc]: Only overridden methods are virtual.
    operator bool() is explicit and overridden. validate() returns void.
    * libxml++/validators/schemavalidatorbase.h: Replace operator const void*()
    by explicit operator bool(). Remove typedef BoolExpr.
    * libxml++/validators/relaxngvalidator.[h|cc]:
    * libxml++/validators/xsdvalidator.[h|cc]: Replace operator const void*()
    by explicit operator bool(). Add override. Bug #754673.

 libxml++/validators/dtdvalidator.cc       |   14 +++++-------
 libxml++/validators/dtdvalidator.h        |   27 ++++++++++++-----------
 libxml++/validators/relaxngvalidator.cc   |    2 +-
 libxml++/validators/relaxngvalidator.h    |   15 +++++--------
 libxml++/validators/schemavalidatorbase.h |   10 +--------
 libxml++/validators/validator.h           |   32 ++++++++++++++++++++++++++++-
 libxml++/validators/xsdvalidator.cc       |    2 +-
 libxml++/validators/xsdvalidator.h        |   15 +++++--------
 8 files changed, 66 insertions(+), 51 deletions(-)
---
diff --git a/libxml++/validators/dtdvalidator.cc b/libxml++/validators/dtdvalidator.cc
index be4e6ca..210064f 100644
--- a/libxml++/validators/dtdvalidator.cc
+++ b/libxml++/validators/dtdvalidator.cc
@@ -32,7 +32,7 @@ DtdValidator::DtdValidator(const Glib::ustring& file)
   parse_subset("",file);
 }
 
-DtdValidator::DtdValidator(const Glib::ustring& external,const Glib::ustring& system)
+DtdValidator::DtdValidator(const Glib::ustring& external, const Glib::ustring& system)
 : dtd_(nullptr)
 {
   parse_subset(external,system);
@@ -49,7 +49,7 @@ void DtdValidator::parse_file(const Glib::ustring& filename)
   parse_subset("",filename);
 }
 
-void DtdValidator::parse_subset(const Glib::ustring& external,const Glib::ustring& system)
+void DtdValidator::parse_subset(const Glib::ustring& external, const Glib::ustring& system)
 {
   release_underlying(); // Free any existing dtd.
   xmlResetLastError();
@@ -106,7 +106,7 @@ void DtdValidator::release_underlying()
   }
 }
 
-DtdValidator::operator bool() const
+DtdValidator::operator bool() const noexcept
 {
   return dtd_ != nullptr;
 }
@@ -121,9 +121,9 @@ const Dtd* DtdValidator::get_dtd() const
   return dtd_;
 }
 
-bool DtdValidator::validate(const Document* doc)
+void DtdValidator::validate(const Document* document)
 {
-  if (!doc)
+  if (!document)
   {
     throw internal_error("Document pointer cannot be 0.");
   }
@@ -145,15 +145,13 @@ bool DtdValidator::validate(const Document* doc)
   xmlResetLastError();
   initialize_valid();
 
-  const bool res = (bool)xmlValidateDtd( valid_, (xmlDoc*)doc->cobj(), dtd_->cobj() );
+  const bool res = (bool)xmlValidateDtd( valid_, (xmlDoc*)document->cobj(), dtd_->cobj() );
 
   if (!res)
   {
     check_for_exception();
     throw validity_error("Document failed DTD validation\n" + format_xml_error());
   }
-
-  return res;
 }
 
 } // namespace xmlpp
diff --git a/libxml++/validators/dtdvalidator.h b/libxml++/validators/dtdvalidator.h
index 01b04c1..aaa7a8d 100644
--- a/libxml++/validators/dtdvalidator.h
+++ b/libxml++/validators/dtdvalidator.h
@@ -15,6 +15,7 @@
 namespace xmlpp {
 
 /** XML DTD validator.
+ * DTD = Document Type Definition
  */
 class DtdValidator : public Validator
 {
@@ -32,45 +33,47 @@ public:
    * @param system The URL of the DTD.
    * @throws xmlpp::parse_error
    */
-  explicit DtdValidator(const Glib::ustring& external,const Glib::ustring& system);
+  explicit DtdValidator(const Glib::ustring& external, const Glib::ustring& system);
 
   ~DtdValidator() override;
 
-  //TODO: Remove virtuals when we can break ABI,
-  //or really put these in the base class.
-
   /** Parse an external subset (DTD file).
    * If the validator already contains a DTD, that DTD is deleted.
    * @param external The external ID of the DTD.
    * @param system The URL of the DTD.
    * @throws xmlpp::parse_error
    */
-  virtual void parse_subset(const Glib::ustring& external,const Glib::ustring& system);
+  void parse_subset(const Glib::ustring& external, const Glib::ustring& system);
 
   /** Parse an external subset (DTD file).
    * If the validator already contains a DTD, that DTD is deleted.
    * @param filename The URL of the DTD.
    * @throws xmlpp::parse_error
    */
-  virtual void parse_file(const Glib::ustring& filename);
+  void parse_file(const Glib::ustring& filename) override;
 
   /** Parse a DTD from a string.
    * If the validator already contains a DTD, that DTD is deleted.
    * @param contents The DTD as a string.
    * @throws xmlpp::parse_error
    */
-  virtual void parse_memory(const Glib::ustring& contents);
+  void parse_memory(const Glib::ustring& contents) override;
 
   /** Parse a DTD from a stream.
    * If the validator already contains a DTD, that DTD is deleted.
    * @param in The stream.
    * @throws xmlpp::parse_error
    */
-  virtual void parse_stream(std::istream& in);
+  void parse_stream(std::istream& in);
 
   /** Test whether a DTD has been parsed.
+   * For instance
+   * @code
+   * if (validator)
+   *   do_something();
+   * @endcode
    */
-  operator bool() const;
+  explicit operator bool() const noexcept override;
 
   /** Get the parsed DTD.
    * @returns A pointer to the parsed DTD, or <tt>0</tt>.
@@ -85,12 +88,11 @@ public:
   /** Validate a document, using a previously parsed DTD.
    * The internal subset (if present) is de-coupled (i.e. not used),
    * which could give problems if ID or IDREF is present.
-   * @param doc Pointer to the document.
-   * @returns Whether the document is valid.
+   * @param document Pointer to the document.
    * @throws xmlpp::internal_error
    * @throws xmlpp::validity_error
    */
-  bool validate(const Document* doc);
+  void validate(const Document* document) override;
 
 protected:
   void release_underlying() override;
@@ -101,4 +103,3 @@ protected:
 } // namespace xmlpp
 
 #endif //__LIBXMLPP_VALIDATORS_DTDVALIDATOR_H
-
diff --git a/libxml++/validators/relaxngvalidator.cc b/libxml++/validators/relaxngvalidator.cc
index 0d00560..bbd9c9a 100644
--- a/libxml++/validators/relaxngvalidator.cc
+++ b/libxml++/validators/relaxngvalidator.cc
@@ -117,7 +117,7 @@ const RelaxNGSchema* RelaxNGValidator::get_schema() const
   return pimpl_->schema;
 }
 
-RelaxNGValidator::operator const void*() const
+RelaxNGValidator::operator bool() const noexcept
 {
   return reinterpret_cast<const void*>(pimpl_->schema && pimpl_->schema->cobj());
 }
diff --git a/libxml++/validators/relaxngvalidator.h b/libxml++/validators/relaxngvalidator.h
index 1f86222..38051c6 100644
--- a/libxml++/validators/relaxngvalidator.h
+++ b/libxml++/validators/relaxngvalidator.h
@@ -71,9 +71,6 @@ public:
 
   ~RelaxNGValidator() override;
 
-  //TODO: Remove virtuals when we can break ABI,
-  //or really put these in the base class.
-
   /** Parse a schema definition file.
    * The schema must be defined with XML syntax (.rng file). The compact syntax
    * (.rnc file) is not supported.
@@ -83,7 +80,7 @@ public:
    * @param filename The URL of the schema.
    * @throws xmlpp::parse_error
    */
-  virtual void parse_file(const Glib::ustring& filename);
+  void parse_file(const Glib::ustring& filename) override;
 
   /** Parse a schema definition from a string.
    * The schema must be defined with XML syntax. The compact syntax is not supported.
@@ -93,7 +90,7 @@ public:
    * @param contents The schema definition as a string.
    * @throws xmlpp::parse_error
    */
-  virtual void parse_memory(const Glib::ustring& contents);
+  void parse_memory(const Glib::ustring& contents) override;
 
   /** Parse a schema definition from a document.
    * If the validator already contains a schema, that schema is released
@@ -101,7 +98,7 @@ public:
    * @param document A preparsed document tree, containing the schema definition.
    * @throws xmlpp::parse_error
    */
-  virtual void parse_document(const Document* document);
+  void parse_document(const Document* document) override;
 
   /** Set a schema.
    * If the validator already contains a schema, that schema is released
@@ -123,7 +120,7 @@ public:
    *   do_something();
    * @endcode
    */
-  virtual operator BoolExpr() const;
+  explicit operator bool() const noexcept override;
 
   /** Get the schema.
    * @returns A pointer to the schema, or <tt>0</tt>.
@@ -140,7 +137,7 @@ public:
    * @throws xmlpp::internal_error
    * @throws xmlpp::validity_error
    */
-  virtual void validate(const Document* document);
+  void validate(const Document* document) override;
 
   /** Validate an XML file, using a previously parsed schema.
    * @param filename The URL of the XML file.
@@ -148,7 +145,7 @@ public:
    * @throws xmlpp::parse_error
    * @throws xmlpp::validity_error
    */
-  virtual void validate(const Glib::ustring& filename);
+  void validate(const Glib::ustring& filename) override;
 
 protected:
   void initialize_valid() override;
diff --git a/libxml++/validators/schemavalidatorbase.h b/libxml++/validators/schemavalidatorbase.h
index 85299fd..18a6a35 100644
--- a/libxml++/validators/schemavalidatorbase.h
+++ b/libxml++/validators/schemavalidatorbase.h
@@ -40,9 +40,6 @@ public:
   SchemaValidatorBase();
   ~SchemaValidatorBase() override;
 
-  //TODO: Remove virtuals when we can break ABI,
-  //or really put these in the base class.
-
   /** Parse a schema definition file.
    * If the validator already contains a schema, that schema is released
    * (deleted if the validator owns the schema).
@@ -67,11 +64,6 @@ public:
    */
   virtual void parse_document(const Document* document) = 0;
 
-  /** This typedef is just to make it more obvious that
-   * our operator const void* should be used like operator bool().
-   */
-  typedef const void* BoolExpr;
-
   /** Test whether a schema has been parsed.
    * For instance
    * @code
@@ -79,7 +71,7 @@ public:
    *   do_something();
    * @endcode
    */
-  virtual operator BoolExpr() const = 0;
+  explicit virtual operator bool() const noexcept = 0;
 
   /** Validate a document, using a previously parsed schema.
    * @param document Pointer to the document.
diff --git a/libxml++/validators/validator.h b/libxml++/validators/validator.h
index 82c94c8..e46f899 100644
--- a/libxml++/validators/validator.h
+++ b/libxml++/validators/validator.h
@@ -12,7 +12,7 @@
 #pragma warning (disable : 4786)
 #endif
 
-#include <libxml++/nodes/element.h>
+#include <libxml++/noncopyable.h>
 #include <libxml++/exceptions/validity_error.h>
 #include <libxml++/exceptions/internal_error.h>
 #include <exception> // std::exception_ptr
@@ -23,6 +23,8 @@ extern "C" {
 
 namespace xmlpp {
 
+class Document;
+
 /** Base class for XML validators.
  */
 class Validator : NonCopyable
@@ -31,6 +33,34 @@ public:
   Validator();
   ~Validator() override;
 
+  /** Parse a schema definition file or an external subset (DTD file).
+   * @param filename The URL of the schema or the DTD.
+   * @throws xmlpp::parse_error
+   */
+  virtual void parse_file(const Glib::ustring& filename) = 0;
+
+  /** Parse a schema definition or a DTD from a string.
+   * @param contents The schema definition or the DTD as a string.
+   * @throws xmlpp::parse_error
+   */
+  virtual void parse_memory(const Glib::ustring& contents) = 0;
+
+  /** Validate a document, using a previously parsed schema or DTD.
+   * @param document Pointer to the document.
+   * @throws xmlpp::internal_error
+   * @throws xmlpp::validity_error
+   */
+  virtual void validate(const Document* document) = 0;
+
+  /** Test whether a schema or a DTD has been parsed.
+   * For instance
+   * @code
+   * if (validator)
+   *   do_something();
+   * @endcode
+   */
+  explicit virtual operator bool() const noexcept = 0;
+
 protected:
   virtual void initialize_valid();
   virtual void release_underlying();
diff --git a/libxml++/validators/xsdvalidator.cc b/libxml++/validators/xsdvalidator.cc
index 674296e..0dd8a09 100644
--- a/libxml++/validators/xsdvalidator.cc
+++ b/libxml++/validators/xsdvalidator.cc
@@ -114,7 +114,7 @@ const XsdSchema* XsdValidator::get_schema() const
   return pimpl_->schema;
 }
 
-XsdValidator::operator const void*() const
+XsdValidator::operator bool() const noexcept
 {
   return reinterpret_cast<const void*>(pimpl_->schema && pimpl_->schema->cobj());
 }
diff --git a/libxml++/validators/xsdvalidator.h b/libxml++/validators/xsdvalidator.h
index bf65ecd..9f784bb 100644
--- a/libxml++/validators/xsdvalidator.h
+++ b/libxml++/validators/xsdvalidator.h
@@ -67,16 +67,13 @@ public:
 
   ~XsdValidator() override;
 
-  //TODO: Remove virtuals when we can break ABI,
-  //or really put these in the base class.
-
   /** Parse a schema definition file.
    * If the validator already contains a schema, that schema is released
    * (deleted if the validator owns the schema).
    * @param filename The URL of the schema.
    * @throws xmlpp::parse_error
    */
-  virtual void parse_file(const Glib::ustring& filename);
+  void parse_file(const Glib::ustring& filename) override;
 
   /** Parse a schema definition from a string.
    * If the validator already contains a schema, that schema is released
@@ -84,7 +81,7 @@ public:
    * @param contents The schema definition as a string.
    * @throws xmlpp::parse_error
    */
-  virtual void parse_memory(const Glib::ustring& contents);
+  void parse_memory(const Glib::ustring& contents) override;
 
   /** Parse a schema definition from a document.
    * If the validator already contains a schema, that schema is released
@@ -92,7 +89,7 @@ public:
    * @param document A preparsed document tree, containing the schema definition.
    * @throws xmlpp::parse_error
    */
-  virtual void parse_document(const Document* document);
+  void parse_document(const Document* document) override;
 
   /** Set a schema.
    * If the validator already contains a schema, that schema is released
@@ -114,7 +111,7 @@ public:
    *   do_something();
    * @endcode
    */
-  virtual operator BoolExpr() const;
+  explicit operator bool() const noexcept override;
 
   /** Get the schema.
    * @returns A pointer to the schema, or <tt>0</tt>.
@@ -131,14 +128,14 @@ public:
    * @throws xmlpp::internal_error
    * @throws xmlpp::validity_error
    */
-  virtual void validate(const Document* document);
+  void validate(const Document* document) override;
 
   /** Validate an XML file, using a previously parsed schema.
    * @param filename The URL of the XML file.
    * @throws xmlpp::internal_error
    * @throws xmlpp::validity_error
    */
-  virtual void validate(const Glib::ustring& filename);
+  void validate(const Glib::ustring& filename) override;
 
 protected:
   void initialize_valid() override;