lib/External/isl/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_constructors();
	printer.print_constructors();
	printer.print_copy_assignment();
	printer.print_destructor();
	printer.print_ptr();
	printer.print_downcast();
	printer.print_ctx();
	osprintf(os, "\n");
	printer.print_persistent_callbacks();
	printer.print_methods();
	printer.print_set_enums();

	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 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());
}

/* 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_public_constructors();
	printer.print_protected_constructors();
	printer.print_constructors();
	printer.print_copy_assignment();
	printer.print_destructor();
	printer.print_ptr();
	printer.print_downcast();
	printer.print_ctx();
	printer.print_persistent_callbacks();
	printer.print_methods();
	printer.print_set_enums();
	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);
	osprintf(os, "  auto saved_ctx = %s_get_ctx(%s);\n",
		clazz.name.c_str(), 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();

	if (method.callback)
		print_callback_local(method.callback);

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

	Method::print_arg_list(os, 0, num_params, [&] (int i) {
		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) {
		ParmVarDecl *param = method.fd->getParamDecl(i);

		print_arg_conversion(param, method.get_param(i));
	});
	osprintf(os, ";\n");
	osprintf(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 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 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) {
		osprintf(os, "  auto saved_ctx = ctx();\n");
		return;
	}
	if (is_isl_ctx(type)) {
		std::string name;

		name = param->getName().str();
		osprintf(os, "  auto saved_ctx = %s;\n", name.c_str());
		return;
	}
	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;
		osprintf(os, "  auto saved_ctx = %s.ctx();\n",
			param->getName().str().c_str());
		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);

	if (method.callback) {
		std::string name;

		name = method.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 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);
}