isl_map_coalesce: avoid ignoring constraints redundant wrt implicit equalities

[isl.git] / interface / plain_cpp.cc

/*
 * Copyright 2016, 2017 Tobias Grosser. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *    1. Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *
 *    2. Redistributions in binary form must reproduce the above
 *       copyright notice, this list of conditions and the following
 *       disclaimer in the documentation and/or other materials provided
 *       with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY TOBIAS GROSSER ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL TOBIAS GROSSER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * The views and conclusions contained in the software and documentation
 * are those of the authors and should not be interpreted as
 * representing official policies, either expressed or implied, of
 * Tobias Grosser.
 */

#include <cstdarg>
#include <cstdio>
#include <iostream>
#include <map>
#include <memory>
#include <sstream>
#include <string>
#include <vector>

#include "plain_cpp.h"
#include "isl_config.h"

/* Print string formatted according to "fmt" to ostream "os".
 *
 * This osprintf method allows us to use printf style formatting constructs when
 * writing to an ostream.
 */
static void osprintf(ostream &os, const char *format, va_list arguments)
{
        va_list copy;
        char *string_pointer;
        size_t size;

        va_copy(copy, arguments);
        size = vsnprintf(NULL, 0, format, copy);
        string_pointer = new char[size + 1];
        va_end(copy);
        vsnprintf(string_pointer, size + 1, format, arguments);
        os << string_pointer;
        delete[] string_pointer;
}

/* Print string formatted according to "fmt" to ostream "os".
 *
 * This osprintf method allows us to use printf style formatting constructs when
 * writing to an ostream.
 */
static void osprintf(ostream &os, const char *format, ...)
{
        va_list arguments;

        va_start(arguments, format);
        osprintf(os, format, arguments);
        va_end(arguments);
}

/* Print string formatted according to "fmt" to ostream "os"
 * with the given indentation.
 *
 * This osprintf method allows us to use printf style formatting constructs when
 * writing to an ostream.
 */
static void osprintf(ostream &os, int indent, const char *format, ...)
{
        va_list arguments;

        osprintf(os, "%*s", indent, " ");
        va_start(arguments, format);
        osprintf(os, format, arguments);
        va_end(arguments);
}

/* Convert "l" to a string.
 */
static std::string to_string(long l)
{
        std::ostringstream strm;
        strm << l;
        return strm.str();
}

/* Construct a generator for plain C++ bindings.
 *
 * "checked" is set if C++ bindings should be generated
 * that rely on the user to check for error conditions.
 */
plain_cpp_generator::plain_cpp_generator(SourceManager &SM,
        set<RecordDecl *> &exported_types,
        set<FunctionDecl *> exported_functions, set<FunctionDecl *> functions,
        bool checked) :
                cpp_generator(SM, exported_types, exported_functions,
                        functions),
                checked(checked)
{
}

/* Generate a cpp interface based on the extracted types and functions.
 *
 * Print first a set of forward declarations for all isl wrapper
 * classes, then the declarations of the classes, and at the end all
 * implementations.
 *
 * If checked C++ bindings are being generated,
 * then wrap them in a namespace to avoid conflicts
 * with the default C++ bindings (with automatic checks using exceptions).
 */
void plain_cpp_generator::generate()
{
        ostream &os = cout;

        osprintf(os, "\n");
        osprintf(os, "namespace isl {\n\n");
        if (checked)
                osprintf(os, "namespace checked {\n\n");

        print_forward_declarations(os);
        osprintf(os, "\n");
        print_declarations(os);
        osprintf(os, "\n");
        print_implementations(os);

        if (checked)
                osprintf(os, "} // namespace checked\n");
        osprintf(os, "} // namespace isl\n");
}

/* Print forward declarations for all classes to "os".
*/
void plain_cpp_generator::print_forward_declarations(ostream &os)
{
        map<string, isl_class>::iterator ci;

        osprintf(os, "// forward declarations\n");

        for (ci = classes.begin(); ci != classes.end(); ++ci)
                print_class_forward_decl(os, ci->second);
}

/* Print all declarations to "os".
 */
void plain_cpp_generator::print_declarations(ostream &os)
{
        map<string, isl_class>::iterator ci;
        bool first = true;

        for (ci = classes.begin(); ci != classes.end(); ++ci) {
                if (first)
                        first = false;
                else
                        osprintf(os, "\n");

                print_class(os, ci->second);
        }
}

/* Print all implementations to "os".
 */
void plain_cpp_generator::print_implementations(ostream &os)
{
        map<string, isl_class>::iterator ci;
        bool first = true;

        for (ci = classes.begin(); ci != classes.end(); ++ci) {
                if (first)
                        first = false;
                else
                        osprintf(os, "\n");

                print_class_impl(os, ci->second);
        }
}

/* If the printed class is a subclass that is based on a type function,
 * then introduce a "type" field that holds the value of the type
 * corresponding to the subclass and make the fields of the class
 * accessible to the "isa" and "as" methods of the (immediate) superclass.
 * In particular, "isa" needs access to the type field itself,
 * while "as" needs access to the private constructor.
 * In case of the "isa" method, all instances are made friends
 * to avoid access right confusion.
 */
void plain_cpp_generator::decl_printer::print_subclass_type()
{
        std::string super;
        const char *cppname = cppstring.c_str();
        const char *supername;

        if (!clazz.is_type_subclass())
                return;

        super = type2cpp(clazz.superclass_name);
        supername = super.c_str();
        osprintf(os, "  template <class T>\n");
        osprintf(os, "  friend %s %s::isa() const;\n",
                generator.isl_bool2cpp().c_str(), supername);
        osprintf(os, "  friend %s %s::as<%s>() const;\n",
                cppname, supername, cppname);
        osprintf(os, "  static const auto type = %s;\n",
                clazz.subclass_name.c_str());
}

/* Print declarations for class "clazz" to "os".
 *
 * If "clazz" is a subclass based on a type function,
 * then it is made to inherit from the (immediate) superclass and
 * a "type" attribute is added for use in the "as" and "isa"
 * methods of the superclass.
 *
 * Conversely, if "clazz" is a superclass with a type function,
 * then declare those "as" and "isa" methods.
 *
 * The pointer to the isl object is only added for classes that
 * are not subclasses, since subclasses refer to the same isl object.
 */
void plain_cpp_generator::print_class(ostream &os, const isl_class &clazz)
{
        decl_printer printer(os, clazz, *this);
        const char *name = clazz.name.c_str();
        const char *cppname = printer.cppstring.c_str();

        osprintf(os, "// declarations for isl::%s\n", cppname);

        printer.print_class_factory();
        osprintf(os, "\n");
        osprintf(os, "class %s ", cppname);
        if (clazz.is_type_subclass())
                osprintf(os, ": public %s ",
                        type2cpp(clazz.superclass_name).c_str());
        osprintf(os, "{\n");
        printer.print_subclass_type();
        printer.print_class_factory("  friend ");
        osprintf(os, "\n");
        osprintf(os, "protected:\n");
        if (!clazz.is_type_subclass()) {
                osprintf(os, "  %s *ptr = nullptr;\n", name);
                osprintf(os, "\n");
        }
        printer.print_protected_constructors();
        osprintf(os, "\n");
        osprintf(os, "public:\n");
        printer.print_public_methods();

        osprintf(os, "};\n");
}

/* Print forward declaration of class "clazz" to "os".
 */
void plain_cpp_generator::print_class_forward_decl(ostream &os,
        const isl_class &clazz)
{
        std::string cppstring = type2cpp(clazz);
        const char *cppname = cppstring.c_str();

        osprintf(os, "class %s;\n", cppname);
}

/* Print global factory functions.
 *
 * Each class has two global factory functions:
 *
 *      set manage(__isl_take isl_set *ptr);
 *      set manage_copy(__isl_keep isl_set *ptr);
 *
 * A user can construct isl C++ objects from a raw pointer and indicate whether
 * they intend to take the ownership of the object or not through these global
 * factory functions. This ensures isl object creation is very explicit and
 * pointers are not converted by accident. Thanks to overloading, manage() and
 * manage_copy() can be called on any isl raw pointer and the corresponding
 * object is automatically created, without the user having to choose the right
 * isl object type.
 *
 * For a subclass based on a type function, no factory functions
 * are introduced because they share the C object type with
 * the superclass.
 */
void plain_cpp_generator::decl_printer::print_class_factory(
        const std::string &prefix)
{
        const char *name = clazz.name.c_str();
        const char *cppname = cppstring.c_str();

        if (clazz.is_type_subclass())
                return;

        os << prefix;
        osprintf(os, "inline %s manage(__isl_take %s *ptr);\n", cppname, name);
        os << prefix;
        osprintf(os, "inline %s manage_copy(__isl_keep %s *ptr);\n",
                cppname, name);
}

/* Print declarations of protected constructors.
 *
 * Each class has currently one protected constructor:
 *
 *      1) Constructor from a plain isl_* C pointer
 *
 * Example:
 *
 *      set(__isl_take isl_set *ptr);
 *
 * The raw pointer constructor is kept protected. Object creation is only
 * possible through manage() or manage_copy().
 */
void plain_cpp_generator::decl_printer::print_protected_constructors()
{
        const char *name = clazz.name.c_str();
        const char *cppname = cppstring.c_str();

        osprintf(os, "  inline explicit %s(__isl_take %s *ptr);\n", cppname,
                 name);
}

/* Print declarations of public constructors.
 *
 * Each class currently has two public constructors:
 *
 *      1) A default constructor
 *      2) A copy constructor
 *
 * Example:
 *
 *      set();
 *      set(const set &set);
 */
void plain_cpp_generator::decl_printer::print_public_constructors()
{
        const char *cppname = cppstring.c_str();
        osprintf(os, "  inline /* implicit */ %s();\n", cppname);

        osprintf(os, "  inline /* implicit */ %s(const %s &obj);\n",
                 cppname, cppname);
}

/* Print declarations for "method".
 */
void plain_cpp_generator::decl_printer::print_method(
        const ConversionMethod &method)
{
        print_full_method_header(method);
}

/* Print declarations for "method".
 */
void plain_cpp_generator::decl_printer::print_method(const Method &method)
{
        print_full_method_header(method);
}

/* Print a declaration for a constructor for the "id" class
 * that takes a user object.
 */
void plain_cpp_generator::decl_printer::print_id_constructor_user()
{
        print_id_constructor_user_header();
}

/* Print a declaration for an "id" method
 * for retrieving the user object associated to the identifier.
 * If "optional" is set, the method returns a std::optional user object.
 */
void plain_cpp_generator::decl_printer::print_id_user(bool optional)
{
        print_id_user_header(optional);
}

/* Print declarations of copy assignment operator.
 *
 * Each class has one assignment operator.
 *
 *      isl:set &set::operator=(set obj)
 *
 */
void plain_cpp_generator::decl_printer::print_copy_assignment()
{
        const char *cppname = cppstring.c_str();

        osprintf(os, "  inline %s &operator=(%s obj);\n", cppname, cppname);
}

/* Print declaration of destructor.
 *
 * No explicit destructor is needed for type based subclasses.
 */
void plain_cpp_generator::decl_printer::print_destructor()
{
        const char *cppname = cppstring.c_str();

        if (clazz.is_type_subclass())
                return;

        osprintf(os, "  inline ~%s();\n", cppname);
}

/* Print declaration of pointer functions.
 * Since type based subclasses share the pointer with their superclass,
 * they can also reuse these functions from the superclass.
 *
 * To obtain a raw pointer three functions are provided:
 *
 *      1) __isl_give isl_set *copy()
 *
 *        Returns a pointer to a _copy_ of the internal object
 *
 *      2) __isl_keep isl_set *get()
 *
 *        Returns a pointer to the internal object
 *
 *      3) __isl_give isl_set *release()
 *
 *        Returns a pointer to the internal object and resets the
 *        internal pointer to nullptr.
 *
 * We also provide functionality to explicitly check if a pointer is
 * currently managed by this object.
 *
 *      4) bool is_null()
 *
 *        Check if the current object is a null pointer.
 *
 * The functions get() and release() model the value_ptr proposed in
 * http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3339.pdf.
 * The copy() function is an extension to allow the user to explicitly
 * copy the underlying object.
 *
 * Also generate a declaration to delete copy() for r-values, for
 * r-values release() should be used to avoid unnecessary copies.
 */
void plain_cpp_generator::decl_printer::print_ptr()
{
        const char *name = clazz.name.c_str();

        if (clazz.is_type_subclass())
                return;

        osprintf(os, "  inline __isl_give %s *copy() const &;\n", name);
        osprintf(os, "  inline __isl_give %s *copy() && = delete;\n", name);
        osprintf(os, "  inline __isl_keep %s *get() const;\n", name);
        osprintf(os, "  inline __isl_give %s *release();\n", name);
        osprintf(os, "  inline bool is_null() const;\n");
}

/* Print a template declaration with given indentation
 * for the "isa_type" method that ensures it is only enabled
 * when called with a template argument
 * that represents a type that is equal to that
 * of the return type of the type function of "super".
 * In particular, "isa_type" gets called from "isa"
 * with as template argument the type of the "type" field
 * of the subclass.
 * The check ensures that this subclass is in fact a direct subclass
 * of "super".
 */
void plain_cpp_generator::decl_printer::print_isa_type_template(int indent,
        const isl_class &super)
{
        osprintf(os, indent,
                "template <typename T,\n");
        osprintf(os, indent,
                "        typename = typename std::enable_if<std::is_same<\n");
        osprintf(os, indent,
                "                const decltype(%s(NULL)),\n",
                super.fn_type->getNameAsString().c_str());
        osprintf(os, indent,
                "                const T>::value>::type>\n");
}

/* Print declarations for the "as" and "isa" methods, if the printed class
 * is a superclass with a type function.
 *
 * "isa" checks whether an object is of a given subclass type.
 * "isa_type" does the same, but gets passed the value of the type field
 * of the subclass as a function argument and the type of this field
 * as a template argument.
 * "as" tries to cast an object to a given subclass type, returning
 * an invalid object if the object is not of the given type.
 */
void plain_cpp_generator::decl_printer::print_downcast()
{
        if (!clazz.fn_type)
                return;

        osprintf(os, "private:\n");
        print_isa_type_template(2, clazz);
        osprintf(os, "  inline %s isa_type(T subtype) const;\n",
                generator.isl_bool2cpp().c_str());
        osprintf(os, "public:\n");
        osprintf(os, "  template <class T> inline %s isa() const;\n",
                generator.isl_bool2cpp().c_str());
        osprintf(os, "  template <class T> inline T as() const;\n");
}

/* Print the declaration of the ctx method.
 */
void plain_cpp_generator::decl_printer::print_ctx()
{
        std::string ns = generator.isl_namespace();

        osprintf(os, "  inline %sctx ctx() const;\n", ns.c_str());
}

/* Print a separator between groups of method declarations.
 */
void plain_cpp_generator::decl_printer::print_method_separator()
{
        os << "\n";
}

/* Add a space to the return type "type" if needed,
 * i.e., if it is not the type of a pointer.
 */
static string add_space_to_return_type(const string &type)
{
        if (type[type.size() - 1] == '*')
                return type;
        return type + " ";
}

/* Print the prototype of the static inline method that is used
 * as the C callback set by "method".
 */
void plain_cpp_generator::plain_printer::print_persistent_callback_prototype(
        FunctionDecl *method)
{
        string callback_name, rettype, c_args;
        ParmVarDecl *param = persistent_callback_arg(method);
        const FunctionProtoType *callback;
        QualType ptype;
        string classname;

        ptype = param->getType();
        callback = extract_prototype(ptype);

        rettype = callback->getReturnType().getAsString();
        rettype = add_space_to_return_type(rettype);
        callback_name = clazz.persistent_callback_name(method);
        c_args = generator.generate_callback_args(ptype, false);

        if (!declarations)
                classname = type2cpp(clazz) + "::";

        osprintf(os, "%s%s%s(%s)",
                 rettype.c_str(), classname.c_str(),
                 callback_name.c_str(), c_args.c_str());
}

/* Print the prototype of the method for setting the callback function
 * set by "method".
 */
void
plain_cpp_generator::plain_printer::print_persistent_callback_setter_prototype(
        FunctionDecl *method)
{
        string classname, callback_name, cpptype;
        ParmVarDecl *param = persistent_callback_arg(method);

        if (!declarations)
                classname = type2cpp(clazz) + "::";

        cpptype = generator.param2cpp(param->getOriginalType());
        callback_name = clazz.persistent_callback_name(method);
        osprintf(os, "void %sset_%s_data(const %s &%s)",
                classname.c_str(), callback_name.c_str(), cpptype.c_str(),
                param->getName().str().c_str());
}

/* Given a method "method" for setting a persistent callback,
 * print the fields that are needed for marshalling the callback.
 *
 * In particular, print
 * - the declaration of a data structure for storing the C++ callback function
 * - a shared pointer to such a data structure
 * - the declaration of a static inline method
 *   for use as the C callback function
 * - the declaration of a private method for setting the callback function
 */
void plain_cpp_generator::decl_printer::print_persistent_callback_data(
        FunctionDecl *method)
{
        string callback_name;
        ParmVarDecl *param = generator.persistent_callback_arg(method);

        callback_name = clazz.persistent_callback_name(method);
        print_callback_data_decl(param, callback_name);
        osprintf(os, ";\n");
        osprintf(os, "  std::shared_ptr<%s_data> %s_data;\n",
                callback_name.c_str(), callback_name.c_str());
        osprintf(os, "  static inline ");
        print_persistent_callback_prototype(method);
        osprintf(os, ";\n");
        osprintf(os, "  inline ");
        print_persistent_callback_setter_prototype(method);
        osprintf(os, ";\n");
}

/* Print declarations needed for the persistent callbacks of the class.
 *
 * In particular, if there are any persistent callbacks, then
 * print a private method for copying callback data from
 * one object to another,
 * private data for keeping track of the persistent callbacks and
 * public methods for setting the persistent callbacks.
 */
void plain_cpp_generator::decl_printer::print_persistent_callbacks()
{
        const char *cppname = cppstring.c_str();

        if (!clazz.has_persistent_callbacks())
                return;

        osprintf(os, "private:\n");
        osprintf(os, "  inline %s &copy_callbacks(const %s &obj);\n",
                cppname, cppname);
        for (const auto &callback : clazz.persistent_callbacks)
                print_persistent_callback_data(callback);

        osprintf(os, "public:\n");
        for (const auto &callback : clazz.persistent_callbacks)
                print_method(Method(clazz, callback));
}

/* Print a declaration for the "get" method "fd",
 * using a name that includes the "get_" prefix.
 */
void plain_cpp_generator::decl_printer::print_get_method(FunctionDecl *fd)
{
        string base = clazz.base_method_name(fd);

        print_method(Method(clazz, fd, base));
}

/* Print implementations for class "clazz" to "os".
 */
void plain_cpp_generator::print_class_impl(ostream &os, const isl_class &clazz)
{
        impl_printer printer(os, clazz, *this);
        const char *cppname = printer.cppstring.c_str();

        osprintf(os, "// implementations for isl::%s", cppname);

        printer.print_class_factory();
        printer.print_protected_constructors();
        printer.print_public_methods();
        printer.print_stream_insertion();
}

/* Print code for throwing an exception corresponding to the last error
 * that occurred on "saved_ctx".
 * This assumes that a valid isl::ctx is available in the "saved_ctx" variable,
 * e.g., through a prior call to print_save_ctx.
 */
static void print_throw_last_error(ostream &os)
{
        osprintf(os, "    exception::throw_last_error(saved_ctx);\n");
}

/* Print code with the given indentation
 * for throwing an exception_invalid with the given message.
 */
static void print_throw_invalid(ostream &os, int indent, const char *msg)
{
        osprintf(os, indent,
                "exception::throw_invalid(\"%s\", __FILE__, __LINE__);\n", msg);
}

/* Print code for throwing an exception on NULL input.
 */
static void print_throw_NULL_input(ostream &os)
{
        print_throw_invalid(os, 4, "NULL input");
}

/* Print code with the given indentation
 * for acting on an invalid error with message "msg".
 * In particular, throw an exception_invalid.
 * In the checked C++ bindings, isl_die is called instead with the code
 * in "checked_code".
 */
void plain_cpp_generator::print_invalid(ostream &os, int indent,
        const char *msg, const char *checked_code)
{
        if (checked)
                osprintf(os, indent,
                        "isl_die(ctx().get(), isl_error_invalid, "
                        "\"%s\", %s);\n", msg, checked_code);
        else
                print_throw_invalid(os, indent, msg);
}

/* Print an operator for inserting objects of the class
 * into an output stream.
 *
 * Unless checked C++ bindings are being generated,
 * the operator requires its argument to be non-NULL.
 * An exception is thrown if anything went wrong during the printing.
 * During this printing, isl is made not to print any error message
 * because the error message is included in the exception.
 *
 * If checked C++ bindings are being generated and anything went wrong,
 * then record this failure in the output stream.
 */
void plain_cpp_generator::impl_printer::print_stream_insertion()
{
        const char *name = clazz.name.c_str();
        const char *cppname = cppstring.c_str();

        if (!clazz.fn_to_str)
                return;

        osprintf(os, "\n");
        osprintf(os, "inline std::ostream &operator<<(std::ostream &os, ");
        osprintf(os, "const %s &obj)\n", cppname);
        osprintf(os, "{\n");
        print_check_ptr_start("obj.get()");
        osprintf(os, "  char *str = %s_to_str(obj.get());\n", name);
        print_check_ptr_end("str");
        if (generator.checked) {
                osprintf(os, "  if (!str) {\n");
                osprintf(os, "    os.setstate(std::ios_base::badbit);\n");
                osprintf(os, "    return os;\n");
                osprintf(os, "  }\n");
        }
        osprintf(os, "  os << str;\n");
        osprintf(os, "  free(str);\n");
        osprintf(os, "  return os;\n");
        osprintf(os, "}\n");
}

/* Print code that checks that "ptr" is not NULL at input.
 *
 * Omit the check if checked C++ bindings are being generated.
 */
void plain_cpp_generator::impl_printer::print_check_ptr(const char *ptr)
{
        if (generator.checked)
                return;

        osprintf(os, "  if (!%s)\n", ptr);
        print_throw_NULL_input(os);
}

/* Print code that checks that "ptr" is not NULL at input and
 * that saves a copy of the isl_ctx of "ptr" for a later check.
 *
 * Omit the check if checked C++ bindings are being generated.
 */
void plain_cpp_generator::impl_printer::print_check_ptr_start(const char *ptr)
{
        if (generator.checked)
                return;

        print_check_ptr(ptr);
        print_save_ctx(clazz.name + "_get_ctx(" + ptr + ")");
        print_on_error_continue();
}

/* Print code that checks that "ptr" is not NULL at the end.
 * A copy of the isl_ctx is expected to have been saved by
 * code generated by print_check_ptr_start.
 *
 * Omit the check if checked C++ bindings are being generated.
 */
void plain_cpp_generator::impl_printer::print_check_ptr_end(const char *ptr)
{
        if (generator.checked)
                return;

        osprintf(os, "  if (!%s)\n", ptr);
        print_throw_last_error(os);
}

/* Print implementation of global factory functions.
 *
 * Each class has two global factory functions:
 *
 *      set manage(__isl_take isl_set *ptr);
 *      set manage_copy(__isl_keep isl_set *ptr);
 *
 * Unless checked C++ bindings are being generated,
 * both functions require the argument to be non-NULL.
 * An exception is thrown if anything went wrong during the copying
 * in manage_copy.
 * During the copying, isl is made not to print any error message
 * because the error message is included in the exception.
 *
 * For a subclass based on a type function, no factory functions
 * are introduced because they share the C object type with
 * the superclass.
 */
void plain_cpp_generator::impl_printer::print_class_factory()
{
        const char *name = clazz.name.c_str();
        const char *cppname = cppstring.c_str();

        if (clazz.is_type_subclass())
                return;

        osprintf(os, "\n");
        osprintf(os, "%s manage(__isl_take %s *ptr) {\n", cppname, name);
        print_check_ptr("ptr");
        osprintf(os, "  return %s(ptr);\n", cppname);
        osprintf(os, "}\n");

        osprintf(os, "%s manage_copy(__isl_keep %s *ptr) {\n", cppname,
                name);
        print_check_ptr_start("ptr");
        osprintf(os, "  ptr = %s_copy(ptr);\n", name);
        print_check_ptr_end("ptr");
        osprintf(os, "  return %s(ptr);\n", cppname);
        osprintf(os, "}\n");
}

/* Print implementations of protected constructors.
 *
 * The pointer to the isl object is either initialized directly or
 * through the (immediate) superclass.
 */
void plain_cpp_generator::impl_printer::print_protected_constructors()
{
        const char *name = clazz.name.c_str();
        const char *cppname = cppstring.c_str();
        bool subclass = clazz.is_type_subclass();

        osprintf(os, "\n");
        osprintf(os, "%s::%s(__isl_take %s *ptr)\n", cppname, cppname, name);
        if (subclass)
                osprintf(os, "    : %s(ptr) {}\n",
                        type2cpp(clazz.superclass_name).c_str());
        else
                osprintf(os, "    : ptr(ptr) {}\n");
}

/* Print implementations of public constructors.
 *
 * The pointer to the isl object is either initialized directly or
 * through the (immediate) superclass.
 *
 * If the class has any persistent callbacks, then copy them
 * from the original object in the copy constructor.
 * If the class is a subclass, then the persistent callbacks
 * are assumed to be copied by the copy constructor of the superclass.
 *
 * Throw an exception from the copy constructor if anything went wrong
 * during the copying or if the input is NULL, if any copying is performed.
 * During the copying, isl is made not to print any error message
 * because the error message is included in the exception.
 * No exceptions are thrown if checked C++ bindings
 * are being generated,
 */
void plain_cpp_generator::impl_printer::print_public_constructors()
{
        std::string super;
        const char *cppname = cppstring.c_str();
        bool subclass = clazz.is_type_subclass();

        osprintf(os, "\n");
        if (subclass)
                super = type2cpp(clazz.superclass_name);
        osprintf(os, "%s::%s()\n", cppname, cppname);
        if (subclass)
                osprintf(os, "    : %s() {}\n\n", super.c_str());
        else
                osprintf(os, "    : ptr(nullptr) {}\n\n");
        osprintf(os, "%s::%s(const %s &obj)\n", cppname, cppname, cppname);
        if (subclass)
                osprintf(os, "    : %s(obj)\n", super.c_str());
        else
                osprintf(os, "    : ptr(nullptr)\n");
        osprintf(os, "{\n");
        if (!subclass) {
                print_check_ptr_start("obj.ptr");
                osprintf(os, "  ptr = obj.copy();\n");
                if (clazz.has_persistent_callbacks())
                        osprintf(os, "  copy_callbacks(obj);\n");
                print_check_ptr_end("ptr");
        }
        osprintf(os, "}\n");
}

/* Print definition for "method",
 * without any automatic type conversions.
 *
 * This method distinguishes three kinds of methods: member methods, static
 * methods, and constructors.
 *
 * Member methods and static methods return a newly managed
 * isl C++ object.
 *
 * Constructors create a new object from a given set of input parameters. They
 * do not return a value, but instead update the pointer stored inside the
 * newly created object.
 *
 * Unless checked C++ bindings are being generated,
 * the inputs of the method are first checked for being valid isl objects and
 * a copy of the associated isl::ctx is saved (if needed).
 * If any failure occurs, either during the check for the inputs or
 * during the isl function call, an exception is thrown.
 * During the function call, isl is made not to print any error message
 * because the error message is included in the exception.
 */
void plain_cpp_generator::impl_printer::print_method(const Method &method)
{
        string methodname = method.fd->getName().str();
        int num_params = method.c_num_params();

        osprintf(os, "\n");
        print_full_method_header(method);
        osprintf(os, "{\n");
        print_argument_validity_check(method);
        print_save_ctx(method);
        print_on_error_continue();

        for (const auto &callback : method.callbacks)
                print_callback_local(callback);

        osprintf(os, "  auto res = %s", methodname.c_str());

        method.print_fd_arg_list(os, 0, num_params, [&] (int i, int arg) {
                method.print_param_use(os, i);
        });
        osprintf(os, ";\n");

        print_exceptional_execution_check(method);
        if (method.kind == Method::Kind::constructor) {
                osprintf(os, "  ptr = res;\n");
        } else {
                print_method_return(method);
        }

        osprintf(os, "}\n");
}

/* Convert argument of type "src" to "dst", with a name specified by "dst".
 *
 * If "src" is the same as "dst", then no argument conversion is needed.
 *
 * Otherwise, call the conversion function
 * with as arguments the isl_ctx of the object and the argument name,
 * or simply the argument name if the source type is an isl type.
 * This means this isl_ctx should be available.
 */
void plain_cpp_generator::impl_printer::print_arg_conversion(ParmVarDecl *dst,
        ParmVarDecl *src)
{
        std::string name = dst->getName().str();
        QualType type = dst->getOriginalType();
        string cpptype = generator.param2cpp(type);

        if (dst == src)
                os << name;
        else if (is_isl_type(src->getOriginalType()))
                os << cpptype << "(" << name << ")";
        else
                os << cpptype << "(ctx(), " << name << ")";
}

/* Print a definition for "method",
 * where "this" or at least one of the argument types needs to be converted.
 *
 * "method" is assumed to be a member method.
 *
 * The generated method performs the required conversion(s) and
 * calls the method generated without conversions.
 *
 * Perform a conversion from the argument in the method declaration
 * (as specified by Method::get_param) to the argument of the C function,
 * if needed.
 * Such a conversion may require the isl_ctx to be available.
 * In order to be able to use this isl_ctx, the current object needs
 * to valid.  The validity of other arguments is checked
 * by the called method.
 */
void plain_cpp_generator::impl_printer::print_method(
        const ConversionMethod &method)
{
        if (method.kind != Method::Kind::member_method)
                die("Automatic conversion currently only supported "
                    "for object methods");

        osprintf(os, "\n");
        print_full_method_header(method);
        osprintf(os, "{\n");
        print_check_ptr("ptr");
        osprintf(os, "  return ");
        method.print_call(os, generator.isl_namespace());
        method.print_cpp_arg_list(os, [&] (int i, int arg) {
                ParmVarDecl *param = method.fd->getParamDecl(i);

                print_arg_conversion(param, method.get_param(i));
        });
        osprintf(os, ";\n");
        osprintf(os, "}\n");
}

/* Print a definition for a constructor for the "id" class
 * that takes a user object.
 *
 * The user object is taken as a std::any and copied into
 * a new std::any object on the heap.
 * A pointer to this heap object is stored in the isl_id and
 * is scheduled to be freed when the reference count of the isl_id
 * drops to zero.
 * If the allocation of the isl_id fails, then the heap object
 * will not be freed automatically, so it needs to be freed manually.
 *
 * Unless checked C++ bindings are being generated,
 * the ctx argument is copied into the save_ctx variable
 * for use by print_throw_last_error, which throws an exception
 * if the construction fails.
 * During the function call, isl is made not to print any error message
 * because the error message is included in the exception.
 */
void plain_cpp_generator::impl_printer::print_id_constructor_user()
{
        print_id_constructor_user_header();
        os << "{\n";
        if (!generator.checked) {
                print_save_ctx("ctx");
                print_on_error_continue();
        }
        os << "  std::any *p = new std::any(any);\n";
        os << "  auto res = isl_id_alloc(ctx.get(), str.c_str(), p);\n";
        os << "  res = isl_id_set_free_user(res, &ctx::free_user);\n";
        os << "  if (!res) {\n";
        os << "    delete p;\n";
        if (!generator.checked)
                print_throw_last_error(os);
        os << "  }\n";
        os << "  ptr = res;\n";
        os << "}\n";
}

/* Print a definition for an "id" method
 * for retrieving the user object associated to the identifier.
 * If "optional" is set, the method returns a std::optional user object.
 * The returned object is of a type specified by template parameter T.
 *
 * The isl_id needs to have been created by the constructor generated
 * by print_id_constructor_user.  That is, it needs to have a user pointer and
 * it needs to have its free_user callback set to &ctx::free_user.
 * The object stored in the std::any also needs to be of the required type.
 *
 * If "optional" is set, return a std::nullopt if any of the checks fail.
 * Otherwise, throw an exception_invalid (or call isl_die and
 * return a default T in the checked C++ bindings).
 */
void plain_cpp_generator::impl_printer::print_id_user(bool optional)
{
        auto fail = [&] (const char *msg) {
                if (optional)
                        os << "    return std::nullopt;\n";
                else
                        generator.print_invalid(os, 4, msg, "return T()");
        };
        os << "\n";
        print_id_user_header(optional);
        os << "{\n";
        print_check_ptr("ptr");
        os << "  std::any *p = (std::any *) isl_id_get_user(ptr);\n";
        os << "  if (!p)\n";
        fail("no user pointer");
        os << "  if (isl_id_get_free_user(ptr) != &ctx::free_user)\n";
        fail("user pointer not attached by C++ interface");
        os << "  T *res = std::any_cast<T>(p);\n";
        os << "  if (!res)\n";
        fail("user pointer not of given type");
        os << "  return *res;\n";
        os << "}\n";
}

/* Print implementation of copy assignment operator.
 *
 * If the class has any persistent callbacks, then copy them
 * from the original object.
 */
void plain_cpp_generator::impl_printer::print_copy_assignment()
{
        const char *name = clazz.name.c_str();
        const char *cppname = cppstring.c_str();

        osprintf(os, "\n");
        osprintf(os, "%s &%s::operator=(%s obj) {\n", cppname,
                 cppname, cppname);
        osprintf(os, "  std::swap(this->ptr, obj.ptr);\n", name);
        if (clazz.has_persistent_callbacks())
                osprintf(os, "  copy_callbacks(obj);\n");
        osprintf(os, "  return *this;\n");
        osprintf(os, "}\n");
}

/* Print implementation of destructor.
 *
 * No explicit destructor is needed for type based subclasses.
 */
void plain_cpp_generator::impl_printer::print_destructor()
{
        const char *name = clazz.name.c_str();
        const char *cppname = cppstring.c_str();

        if (clazz.is_type_subclass())
                return;

        osprintf(os, "\n");
        osprintf(os, "%s::~%s() {\n", cppname, cppname);
        osprintf(os, "  if (ptr)\n");
        osprintf(os, "    %s_free(ptr);\n", name);
        osprintf(os, "}\n");
}

/* Print a check that the persistent callback corresponding to "fd"
 * is not set, throwing an exception (or printing an error message
 * and returning nullptr) if it is set.
 */
void plain_cpp_generator::print_check_no_persistent_callback(ostream &os,
        const isl_class &clazz, FunctionDecl *fd)
{
        string callback_name = clazz.persistent_callback_name(fd);

        osprintf(os, "  if (%s_data)\n", callback_name.c_str());
        print_invalid(os, 4, "cannot release object with persistent callbacks",
                            "return nullptr");
}

/* Print implementation of ptr() functions.
 * Since type based subclasses share the pointer with their superclass,
 * they can also reuse these functions from the superclass.
 *
 * If an object has persistent callbacks set, then the underlying
 * C object pointer cannot be released because it references data
 * in the C++ object.
 */
void plain_cpp_generator::impl_printer::print_ptr()
{
        const char *name = clazz.name.c_str();
        const char *cppname = cppstring.c_str();
        set<FunctionDecl *>::const_iterator in;
        const set<FunctionDecl *> &callbacks = clazz.persistent_callbacks;

        if (clazz.is_type_subclass())
                return;

        osprintf(os, "\n");
        osprintf(os, "__isl_give %s *%s::copy() const & {\n", name, cppname);
        osprintf(os, "  return %s_copy(ptr);\n", name);
        osprintf(os, "}\n\n");
        osprintf(os, "__isl_keep %s *%s::get() const {\n", name, cppname);
        osprintf(os, "  return ptr;\n");
        osprintf(os, "}\n\n");
        osprintf(os, "__isl_give %s *%s::release() {\n", name, cppname);
        for (in = callbacks.begin(); in != callbacks.end(); ++in)
                generator.print_check_no_persistent_callback(os, clazz, *in);
        osprintf(os, "  %s *tmp = ptr;\n", name);
        osprintf(os, "  ptr = nullptr;\n");
        osprintf(os, "  return tmp;\n");
        osprintf(os, "}\n\n");
        osprintf(os, "bool %s::is_null() const {\n", cppname);
        osprintf(os, "  return ptr == nullptr;\n");
        osprintf(os, "}\n");
}

/* Print implementations for the "as" and "isa" methods, if the printed class
 * is a superclass with a type function.
 *
 * "isa" checks whether an object is of a given subclass type.
 * "isa_type" does the same, but gets passed the value of the type field
 * of the subclass as a function argument and the type of this field
 * as a template argument.
 * "as" casts an object to a given subclass type, erroring out
 * if the object is not of the given type.
 *
 * If the input is an invalid object, then these methods raise
 * an exception.
 * If checked bindings are being generated,
 * then an invalid boolean or object is returned instead.
 */
void plain_cpp_generator::impl_printer::print_downcast()
{
        const char *cppname = cppstring.c_str();

        if (!clazz.fn_type)
                return;

        osprintf(os, "\n");
        osprintf(os, "template <typename T, typename>\n");
        osprintf(os, "%s %s::isa_type(T subtype) const\n",
                generator.isl_bool2cpp().c_str(), cppname);
        osprintf(os, "{\n");
        osprintf(os, "  if (is_null())\n");
        if (generator.checked)
                osprintf(os, "    return boolean();\n");
        else
                print_throw_NULL_input(os);
        osprintf(os, "  return %s(get()) == subtype;\n",
                clazz.fn_type->getNameAsString().c_str());
        osprintf(os, "}\n");

        osprintf(os, "template <class T>\n");
        osprintf(os, "%s %s::isa() const\n",
                generator.isl_bool2cpp().c_str(), cppname);
        osprintf(os, "{\n");
        osprintf(os, "  return isa_type<decltype(T::type)>(T::type);\n");
        osprintf(os, "}\n");

        osprintf(os, "template <class T>\n");
        osprintf(os, "T %s::as() const\n", cppname);
        osprintf(os, "{\n");
        if (generator.checked)
                osprintf(os, " if (isa<T>().is_false())\n");
        else
                osprintf(os, " if (!isa<T>())\n");
        generator.print_invalid(os, 4, "not an object of the requested subtype",
                    "return T()");
        osprintf(os, "  return T(copy());\n");
        osprintf(os, "}\n");
}

/* Print the implementation of the ctx method.
 */
void plain_cpp_generator::impl_printer::print_ctx()
{
        const char *name = clazz.name.c_str();
        const char *cppname = cppstring.c_str();
        std::string ns = generator.isl_namespace();

        osprintf(os, "\n");
        osprintf(os, "%sctx %s::ctx() const {\n", ns.c_str(), cppname);
        osprintf(os, "  return %sctx(%s_get_ctx(ptr));\n", ns.c_str(), name);
        osprintf(os, "}\n");
}

/* Print a separator between groups of method definitions.
 *
 * No additional separator is required between method definitions.
 */
void plain_cpp_generator::impl_printer::print_method_separator()
{
}

/* Print the implementations of the methods needed for the persistent callbacks
 * of the class.
 */
void plain_cpp_generator::impl_printer::print_persistent_callbacks()
{
        const char *cppname = cppstring.c_str();
        string classname = type2cpp(clazz);

        if (!clazz.has_persistent_callbacks())
                return;

        osprintf(os, "\n");
        osprintf(os, "%s &%s::copy_callbacks(const %s &obj)\n",
                cppname, classname.c_str(), cppname);
        osprintf(os, "{\n");
        for (const auto &callback : clazz.persistent_callbacks) {
                string callback_name = clazz.persistent_callback_name(callback);

                osprintf(os, "  %s_data = obj.%s_data;\n",
                        callback_name.c_str(), callback_name.c_str());
        }
        osprintf(os, "  return *this;\n");
        osprintf(os, "}\n");

        for (const auto &callback : clazz.persistent_callbacks)
                print_set_persistent_callback(Method(clazz, callback));
}

/* Print a definition for the "get" method "fd" in class "clazz",
 * using a name that includes the "get_" prefix, to "os".
 *
 * This definition simply calls the variant without the "get_" prefix and
 * returns its result.
 * Note that static methods are not considered to be "get" methods.
 */
void plain_cpp_generator::impl_printer::print_get_method(FunctionDecl *fd)
{
        string get_name = clazz.base_method_name(fd);
        string name = clazz.method_name(fd);
        int num_params = fd->getNumParams();

        osprintf(os, "\n");
        print_full_method_header(Method(clazz, fd, get_name));
        osprintf(os, "{\n");
        osprintf(os, "  return %s(", name.c_str());
        for (int i = 1; i < num_params; ++i) {
                ParmVarDecl *param = fd->getParamDecl(i);

                if (i != 1)
                        osprintf(os, ", ");
                osprintf(os, "%s", param->getName().str().c_str());
        }
        osprintf(os, ");\n");
        osprintf(os, "}\n");
}

/* Print code that checks that all isl object arguments to "method" are valid
 * (not NULL) and throws an exception if they are not.
 *
 * If checked bindings are being generated,
 * then no such check is performed.
 */
void plain_cpp_generator::impl_printer::print_argument_validity_check(
        const Method &method)
{
        int n;
        bool first = true;

        if (generator.checked)
                return;

        n = method.num_params();
        for (int i = 0; i < n; ++i) {
                bool is_this;
                ParmVarDecl *param = method.fd->getParamDecl(i);
                string name = param->getName().str();
                const char *name_str = name.c_str();
                QualType type = param->getOriginalType();

                is_this = i == 0 && method.kind == Method::Kind::member_method;
                if (!is_this && (is_isl_ctx(type) || !is_isl_type(type)))
                        continue;

                if (first)
                        osprintf(os, "  if (");
                else
                        osprintf(os, " || ");

                if (is_this)
                        osprintf(os, "!ptr");
                else
                        osprintf(os, "%s.is_null()", name_str);

                first = false;
        }
        if (first)
                return;
        osprintf(os, ")\n");
        print_throw_NULL_input(os);
}

/* Print code for saving a copy of "ctx" in a "saved_ctx" variable.
 */
void plain_cpp_generator::impl_printer::print_save_ctx(const std::string &ctx)
{
        os << "  auto saved_ctx = " << ctx << ";\n";
}

/* Print code for saving a copy of the isl::ctx available at the start
 * of the method "method" in a "saved_ctx" variable,
 * for use in exception handling.
 *
 * If checked bindings are being generated,
 * then the "saved_ctx" variable is not needed.
 * If "method" is a member function, then obtain the isl_ctx from
 * the "this" object.
 * If the first argument of the method is an isl::ctx, then use that one.
 * Otherwise, save a copy of the isl::ctx associated to the first argument
 * of isl object type.
 */
void plain_cpp_generator::impl_printer::print_save_ctx(const Method &method)
{
        int n;
        ParmVarDecl *param = method.fd->getParamDecl(0);
        QualType type = param->getOriginalType();

        if (generator.checked)
                return;
        if (method.kind == Method::Kind::member_method)
                return print_save_ctx("ctx()");
        if (is_isl_ctx(type))
                return print_save_ctx(param->getName().str());
        n = method.num_params();
        for (int i = 0; i < n; ++i) {
                ParmVarDecl *param = method.fd->getParamDecl(i);
                QualType type = param->getOriginalType();

                if (!is_isl_type(type))
                        continue;
                print_save_ctx(param->getName().str() + ".ctx()");
                return;
        }
}

/* Print code to make isl not print an error message when an error occurs
 * within the current scope (if exceptions are available),
 * since the error message will be included in the exception.
 * If exceptions are not available, then exception::on_error
 * is set to ISL_ON_ERROR_ABORT and isl is therefore made to abort instead.
 *
 * If checked bindings are being generated,
 * then leave it to the user to decide what isl should do on error.
 * Otherwise, assume that a valid isl::ctx is available
 * in the "saved_ctx" variable,
 * e.g., through a prior call to print_save_ctx.
 */
void plain_cpp_generator::impl_printer::print_on_error_continue()
{
        if (generator.checked)
                return;
        osprintf(os, "  options_scoped_set_on_error saved_on_error(saved_ctx, "
                     "exception::on_error);\n");
}

/* Print code to "os" that checks whether any of the persistent callbacks
 * of the class of "method" is set and if it failed with an exception.
 * If so, the "eptr" in the corresponding data structure contains the exception
 * that was caught and that needs to be rethrown.
 * This field is cleared because the callback and its data may get reused.
 *
 * The check only needs to be generated for member methods since
 * an object is needed for any of the persistent callbacks to be set.
 */
static void print_persistent_callback_exceptional_execution_check(ostream &os,
        const Method &method)
{
        if (method.kind != Method::Kind::member_method)
                return;

        for (const auto &pcb : method.clazz.persistent_callbacks) {
                auto callback_name = method.clazz.persistent_callback_name(pcb);

                osprintf(os, "  if (%s_data && %s_data->eptr) {\n",
                        callback_name.c_str(), callback_name.c_str());
                osprintf(os, "    std::exception_ptr eptr = %s_data->eptr;\n",
                        callback_name.c_str());
                osprintf(os, "    %s_data->eptr = nullptr;\n",
                        callback_name.c_str());
                osprintf(os, "    std::rethrow_exception(eptr);\n");
                osprintf(os, "  }\n");
        }
}

/* Print code that checks whether the execution of the core of "method"
 * was successful.
 *
 * If checked bindings are being generated,
 * then no checks are performed.
 *
 * Otherwise, first check if any of the callbacks failed with
 * an exception.  If so, the "eptr" in the corresponding data structure
 * contains the exception that was caught and that needs to be rethrown.
 * Then check if the function call failed in any other way and throw
 * the appropriate exception.
 * In particular, if the return type is isl_stat, isl_bool or isl_size,
 * then a negative value indicates a failure.  If the return type
 * is an isl type, then a NULL value indicates a failure.
 * Assume print_save_ctx has made sure that a valid isl::ctx
 * is available in the "ctx" variable.
 */
void plain_cpp_generator::impl_printer::print_exceptional_execution_check(
        const Method &method)
{
        bool check_null, check_neg;
        QualType return_type = method.fd->getReturnType();

        if (generator.checked)
                return;

        print_persistent_callback_exceptional_execution_check(os, method);

        for (const auto &callback : method.callbacks) {
                std::string name;

                name = callback->getName().str();
                osprintf(os, "  if (%s_data.eptr)\n", name.c_str());
                osprintf(os, "    std::rethrow_exception(%s_data.eptr);\n",
                        name.c_str());
        }

        check_neg = is_isl_neg_error(return_type);
        check_null = is_isl_type(return_type);
        if (!check_null && !check_neg)
                return;

        if (check_neg)
                osprintf(os, "  if (res < 0)\n");
        else
                osprintf(os, "  if (!res)\n");
        print_throw_last_error(os);
}

/* Return a pointer to the appropriate type printer,
 * i.e., the regular type printer or the checked type printer
 * depending on the setting of this->checked.
 */
std::unique_ptr<cpp_type_printer> plain_cpp_generator::type_printer()
{
        cpp_type_printer *printer;

        if (checked)
                printer = new checked_cpp_type_printer();
        else
                printer = new cpp_type_printer();

        return std::unique_ptr<cpp_type_printer>(printer);
}

/* Return the C++ return type of the method "method".
 *
 * Use the appropriate type printer.
 */
std::string plain_cpp_generator::get_return_type(const Method &method)
{
        return type_printer()->return_type(method);
}

/* Given a method "method" for setting a persistent callback of its class,
 * print the implementations of the methods needed for that callback.
 *
 * In particular, print
 * - the implementation of a static inline method
 *   for use as the C callback function
 * - the definition of a private method for setting the callback function
 * - the public method for constructing a new object with the callback set.
 */
void plain_cpp_generator::impl_printer::print_set_persistent_callback(
        const Method &method)
{
        string fullname = method.fd->getName().str();
        ParmVarDecl *param = persistent_callback_arg(method.fd);
        string pname;
        string callback_name = clazz.persistent_callback_name(method.fd);

        osprintf(os, "\n");
        print_persistent_callback_prototype(method.fd);
        osprintf(os, "\n");
        osprintf(os, "{\n");
        print_callback_body(2, param, callback_name);
        osprintf(os, "}\n\n");

        pname = param->getName().str();
        print_persistent_callback_setter_prototype(method.fd);
        osprintf(os, "\n");
        osprintf(os, "{\n");
        print_check_ptr_start("ptr");
        osprintf(os, "  %s_data = std::make_shared<struct %s_data>();\n",
                callback_name.c_str(), callback_name.c_str());
        osprintf(os, "  %s_data->func = %s;\n",
                callback_name.c_str(), pname.c_str());
        osprintf(os, "  ptr = %s(ptr, &%s, %s_data.get());\n",
                fullname.c_str(), callback_name.c_str(), callback_name.c_str());
        print_check_ptr_end("ptr");
        osprintf(os, "}\n\n");

        print_full_method_header(method);
        osprintf(os, "{\n");
        osprintf(os, "  auto copy = *this;\n");
        osprintf(os, "  copy.set_%s_data(%s);\n",
                callback_name.c_str(), pname.c_str());
        osprintf(os, "  return copy;\n");
        osprintf(os, "}\n");
}

/* Print the return statement of the C++ method "method".
 *
 * The result of the corresponding isl function is returned as a new
 * object if the underlying isl function returns an isl_* ptr, as a bool
 * if the isl function returns an isl_bool, as void if the isl functions
 * returns an isl_stat,
 * as std::string if the isl function returns 'const char *', and as
 * unmodified return value otherwise.
 * If checked C++ bindings are being generated,
 * then an isl_bool return type is transformed into a boolean and
 * an isl_stat into a stat since no exceptions can be generated
 * on negative results from the isl function.
 * If the method returns a new instance of the same object type and
 * if the class has any persistent callbacks, then the data
 * for these callbacks are copied from the original to the new object.
 * If "clazz" is a subclass that is based on a type function and
 * if the return type corresponds to the superclass data type,
 * then it is replaced by the subclass data type.
 */
void plain_cpp_generator::impl_printer::print_method_return(
        const Method &method)
{
        QualType return_type = method.fd->getReturnType();
        string rettype_str = generator.get_return_type(method);
        bool returns_super = method.is_subclass_mutator();

        if (is_isl_type(return_type) ||
                    (generator.checked && is_isl_neg_error(return_type))) {
                osprintf(os, "  return manage(res)");
                if (is_mutator(clazz, method.fd) &&
                    clazz.has_persistent_callbacks())
                        osprintf(os, ".copy_callbacks(*this)");
                if (returns_super)
                        osprintf(os, ".as<%s>()", rettype_str.c_str());
                osprintf(os, ";\n");
        } else if (is_isl_stat(return_type)) {
                osprintf(os, "  return;\n");
        } else if (is_string(return_type)) {
                osprintf(os, "  std::string tmp(res);\n");
                if (gives(method.fd))
                        osprintf(os, "  free(res);\n");
                osprintf(os, "  return tmp;\n");
        } else {
                osprintf(os, "  return res;\n");
        }
}

/* Print the header for "method", including the terminating semicolon
 * in case of a declaration and a newline.
 *
 * Use the appropriate type printer to print argument and return types.
 */
void plain_cpp_generator::plain_printer::print_full_method_header(
        const Method &method)
{
        auto type_printer = generator.type_printer();

        print_method_header(method, *type_printer);

        if (declarations)
                osprintf(os, ";");
        osprintf(os, "\n");
}

/* Generate the list of argument types for a callback function of
 * type "type".  If "cpp" is set, then generate the C++ type list, otherwise
 * the C type list.
 *
 * Use the appropriate type printer.
 * For the plain C++ interface, the argument position is irrelevant,
 * so simply pass in -1.
 */
string plain_cpp_generator::generate_callback_args(QualType type, bool cpp)
{
        return type_printer()->generate_callback_args(-1, type, cpp);
}

/* Generate the full cpp type of a callback function of type "type".
 *
 * Use the appropriate type printer.
 * For the plain C++ interface, the argument position is irrelevant,
 * so simply pass in -1.
 */
string plain_cpp_generator::generate_callback_type(QualType type)
{
        return type_printer()->generate_callback_type(-1, type);
}

/* Print the call to the C++ callback function "call",
 * with the given indentation, wrapped
 * for use inside the lambda function that is used as the C callback function,
 * in the case where checked C++ bindings are being generated.
 *
 * In particular, print
 *
 *        auto ret = @call@;
 *        return ret.release();
 */
void plain_cpp_generator::impl_printer::print_wrapped_call_checked(int indent,
        const string &call)
{
        osprintf(os, indent, "auto ret = %s;\n", call.c_str());
        osprintf(os, indent, "return ret.release();\n");
}

/* Print the call to the C++ callback function "call",
 * with the given indentation and with return type "rtype", wrapped
 * for use inside the lambda function that is used as the C callback function.
 *
 * In particular, print
 *
 *        ISL_CPP_TRY {
 *          @call@;
 *          return isl_stat_ok;
 *        } ISL_CPP_CATCH_ALL {
 *          data->eptr = std::current_exception();
 *          return isl_stat_error;
 *        }
 * or
 *        ISL_CPP_TRY {
 *          auto ret = @call@;
 *          return ret ? isl_bool_true : isl_bool_false;
 *        } ISL_CPP_CATCH_ALL {
 *          data->eptr = std::current_exception();
 *          return isl_bool_error;
 *        }
 * or
 *        ISL_CPP_TRY {
 *          auto ret = @call@;
 *          return ret.release();
 *        } ISL_CPP_CATCH_ALL {
 *          data->eptr = std::current_exception();
 *          return NULL;
 *        }
 *
 * depending on the return type.
 *
 * where ISL_CPP_TRY is defined to "try" and ISL_CPP_CATCH_ALL to "catch (...)"
 * (if exceptions are available).
 *
 * If checked C++ bindings are being generated, then
 * the call is wrapped differently.
 */
void plain_cpp_generator::impl_printer::print_wrapped_call(int indent,
        const string &call, QualType rtype)
{
        if (generator.checked)
                return print_wrapped_call_checked(indent, call);

        osprintf(os, indent, "ISL_CPP_TRY {\n");
        if (is_isl_stat(rtype))
                osprintf(os, indent, "  %s;\n", call.c_str());
        else
                osprintf(os, indent, "  auto ret = %s;\n", call.c_str());
        if (is_isl_stat(rtype))
                osprintf(os, indent, "  return isl_stat_ok;\n");
        else if (is_isl_bool(rtype))
                osprintf(os, indent,
                        "  return ret ? isl_bool_true : isl_bool_false;\n");
        else
                osprintf(os, indent, "  return ret.release();\n");
        osprintf(os, indent, "} ISL_CPP_CATCH_ALL {\n");
        osprintf(os, indent, "  data->eptr = std::current_exception();\n");
        if (is_isl_stat(rtype))
                osprintf(os, indent, "  return isl_stat_error;\n");
        else if (is_isl_bool(rtype))
                osprintf(os, indent, "  return isl_bool_error;\n");
        else
                osprintf(os, indent, "  return NULL;\n");
        osprintf(os, indent, "}\n");
}

/* Print the declaration for a "prefix"_data data structure
 * that can be used for passing to a C callback function
 * containing a copy of the C++ callback function "param",
 * along with an std::exception_ptr that is used to store any
 * exceptions thrown in the C++ callback.
 *
 * If the C callback is of the form
 *
 *      isl_stat (*fn)(__isl_take isl_map *map, void *user)
 *
 * then the following declaration is printed:
 *
 *      struct <prefix>_data {
 *        std::function<stat(map)> func;
 *        std::exception_ptr eptr;
 *      }
 *
 * (without a newline or a semicolon).
 *
 * The std::exception_ptr object is not added to "prefix"_data
 * if checked C++ bindings are being generated.
 */
void plain_cpp_generator::plain_printer::print_callback_data_decl(
        ParmVarDecl *param,
        const string &prefix)
{
        string cpp_args;

        cpp_args = generator.generate_callback_type(param->getType());

        osprintf(os, "  struct %s_data {\n", prefix.c_str());
        osprintf(os, "    %s func;\n", cpp_args.c_str());
        if (!generator.checked)
                osprintf(os, "    std::exception_ptr eptr;\n");
        osprintf(os, "  }");
}

/* Given a group of methods with the same name,
 * should extra methods be added that take as arguments
 * those types that can be converted to the original argument type
 * through a unary constructor?
 *
 * Note that even if this method returns true,
 * the extra methods are only printed by the caller
 * if exactly one of the methods in the group was originally defined
 * in the printed class.
 * Signal that they should be printed if the group contains
 * both methods originally defined in the printed class and
 * methods that have been copied from an ancestor
 * by checking whether there are at least two methods in the group.
 */
bool plain_cpp_generator::plain_printer::want_descendent_overloads(
        const function_set &methods)
{
        return methods.size() > 1;
}

/* Print the header of the constructor for the "id" class
 * that takes a user object.
 *
 * The user object is taken as a std::any.
 */
void plain_cpp_generator::plain_printer::print_id_constructor_user_header()
{
        if (declarations)
                os << "  inline explicit ";
        else
                os << "id::";
        os << "id(" << generator.isl_namespace() << "ctx ctx, "
           << "const std::string &str, const std::any &any)";
        if (declarations)
                os << ";";
        os << "\n";
}

/* Print the header of the "id" method
 * for retrieving the user object associated to the identifier.
 * If "optional" is set, the method returns a std::optional user object.
 * The returned object is of a type specified by template parameter T.
 */
void plain_cpp_generator::plain_printer::print_id_user_header(bool optional)
{
        auto indent = declarations ? "  " : "";
        os << indent << "template <class T>\n";
        os << indent << (optional ? "std::optional<T> " : "T ");
        if (!declarations)
                os << "id::";
        os << (optional ? "try_" : "");
        os << "user() const";
        if (declarations)
                os << ";";
        os << "\n";
}

/* Perform printing by "fn" in a context that only gets compiled
 * by C++17 compilers.
 */
static void on_cplusplus17(ostream &os, const std::function<void(void)> &fn)
{
        os << "#if __cplusplus >= 201703L\n";
        fn();
        os << "#endif\n";
}

/* Print declarations or definitions of the special methods of the "id" class
 * that are not automatically derived from the C interface.
 *
 * In particular, print a constructor that takes a user pointer
 * as well as methods for retrieving this user pointer.
 *
 * These methods require C++17 features.
 */
void plain_cpp_generator::plain_printer::print_special_id()
{
        os << "\n";
        on_cplusplus17(os, [this] () {
                print_id_constructor_user();
                print_id_user(true);
                print_id_user(false);
        });
}

/* Print declarations or definitions of any special methods of this class
 * not automatically derived from the C interface.
 *
 * In particular, print special methods for the "id" class.
 */
void plain_cpp_generator::plain_printer::print_special()
{
        if (clazz.name == "isl_id")
                print_special_id();
}

/* Print declarations or definitions of the public methods.
 */
void plain_cpp_generator::plain_printer::print_public_methods()
{
        print_public_constructors();
        print_constructors();
        print_copy_assignment();
        print_destructor();
        print_ptr();
        print_downcast();
        print_ctx();
        print_method_separator();
        print_persistent_callbacks();
        print_methods();
        print_set_enums();
        print_special();
}

/* Print the body of C function callback with the given indentation
 * that can be use as an argument to "param" for marshalling
 * the corresponding C++ callback.
 * The data structure that contains the C++ callback is of type
 * "prefix"_data.
 *
 * For a callback of the form
 *
 *      isl_stat (*fn)(__isl_take isl_map *map, void *user)
 *
 * the following code is generated:
 *
 *        auto *data = static_cast<struct <prefix>_data *>(arg_1);
 *        ISL_CPP_TRY {
 *          stat ret = (data->func)(manage(arg_0));
 *          return isl_stat_ok;
 *        } ISL_CPP_CATCH_ALL {
 *          data->eptr = std::current_exception();
 *          return isl_stat_error;
 *        }
 *
 * If checked C++ bindings are being generated, then
 * generate the following code:
 *
 *        auto *data = static_cast<struct <prefix>_data *>(arg_1);
 *        stat ret = (data->func)(manage(arg_0));
 *        return isl_stat(ret);
 */
void plain_cpp_generator::impl_printer::print_callback_body(int indent,
        ParmVarDecl *param, const string &prefix)
{
        QualType ptype, rtype;
        string call, last_idx;
        const FunctionProtoType *callback;
        int num_params;

        ptype = param->getType();

        callback = extract_prototype(ptype);
        rtype = callback->getReturnType();
        num_params = callback->getNumArgs();

        last_idx = ::to_string(num_params - 1);

        call = "(data->func)(";
        for (long i = 0; i < num_params - 1; i++) {
                if (!generator.callback_takes_argument(param, i))
                        call += "manage_copy";
                else
                        call += "manage";
                call += "(arg_" + ::to_string(i) + ")";
                if (i != num_params - 2)
                        call += ", ";
        }
        call += ")";

        osprintf(os, indent,
                 "auto *data = static_cast<struct %s_data *>(arg_%s);\n",
                 prefix.c_str(), last_idx.c_str());
        print_wrapped_call(indent, call, rtype);
}

/* Print the local variables that are needed for a callback argument,
 * in particular, print a lambda function that wraps the callback and
 * a pointer to the actual C++ callback function.
 *
 * For a callback of the form
 *
 *      isl_stat (*fn)(__isl_take isl_map *map, void *user)
 *
 * the following lambda function is generated:
 *
 *      auto fn_lambda = [](isl_map *arg_0, void *arg_1) -> isl_stat {
 *        auto *data = static_cast<struct fn_data *>(arg_1);
 *        try {
 *          stat ret = (data->func)(manage(arg_0));
 *          return isl_stat_ok;
 *        } catch (...) {
 *          data->eptr = std::current_exception();
 *          return isl_stat_error;
 *        }
 *      };
 *
 * A copy of the std::function C++ callback function is stored in
 * a fn_data data structure for passing to the C callback function,
 * along with an std::exception_ptr that is used to store any
 * exceptions thrown in the C++ callback.
 *
 *      struct fn_data {
 *        std::function<stat(map)> func;
 *        std::exception_ptr eptr;
 *      } fn_data = { fn };
 *
 * This std::function object represents the actual user
 * callback function together with the locally captured state at the caller.
 *
 * The lambda function is expected to be used as a C callback function
 * where the lambda itself is provided as the function pointer and
 * where the user void pointer is a pointer to fn_data.
 * The std::function object is extracted from the pointer to fn_data
 * inside the lambda function.
 *
 * The std::exception_ptr object is not added to fn_data
 * if checked C++ bindings are being generated.
 * The body of the generated lambda function then is as follows:
 *
 *        stat ret = (data->func)(manage(arg_0));
 *        return isl_stat(ret);
 *
 * If the C callback does not take its arguments, then
 * manage_copy is used instead of manage.
 */
void plain_cpp_generator::impl_printer::print_callback_local(ParmVarDecl *param)
{
        string pname;
        QualType ptype, rtype;
        string c_args, cpp_args, rettype;
        const FunctionProtoType *callback;

        pname = param->getName().str();
        ptype = param->getType();

        c_args = generator.generate_callback_args(ptype, false);

        callback = extract_prototype(ptype);
        rtype = callback->getReturnType();
        rettype = rtype.getAsString();

        print_callback_data_decl(param, pname);
        osprintf(os, " %s_data = { %s };\n", pname.c_str(), pname.c_str());
        osprintf(os, "  auto %s_lambda = [](%s) -> %s {\n",
                 pname.c_str(), c_args.c_str(), rettype.c_str());
        print_callback_body(4, param, pname);
        osprintf(os, "  };\n");
}

/* Return the C++ counterpart to the isl_bool type.
 *
 * For the checked C++ bindings this is "boolean".
 */
std::string checked_cpp_type_printer::isl_bool() const
{
        return "boolean";
}

/* Return the C++ counterpart to the isl_bool type.
 *
 * Use the appropriate type printer.
 */
string plain_cpp_generator::isl_bool2cpp()
{
        return type_printer()->isl_bool();
}

/* Return the C++ counterpart to the isl_stat type.
 *
 * For the checked C++ bindings this is "stat".
 */
string checked_cpp_type_printer::isl_stat() const
{
        return "stat";
}

/* Return the C++ counterpart to the isl_size type.
 *
 * For the checked C++ bindings this is "class size".
 */
string checked_cpp_type_printer::isl_size() const
{
        return "class size";
}

/* Return the namespace of the generated C++ bindings.
 *
 * For the checked C++ bindings this is "isl::checked::".
 */
std::string checked_cpp_type_printer::isl_namespace() const
{
        return "isl::checked::";
}

/* Return the namespace of the generated C++ bindings.
 *
 * Use the appropriate type printer.
 */
string plain_cpp_generator::isl_namespace()
{
        return type_printer()->isl_namespace();
}

/* Translate parameter or return type "type" to its C++ name counterpart.
 *
 * Use the appropriate type printer.
 * For the plain C++ interface, the argument position is irrelevant,
 * so simply pass in -1.
 */
string plain_cpp_generator::param2cpp(QualType type)
{
        return type_printer()->param(-1, type);
}