iverilog/tgt-vhdl/vhdl_element.hh

77 lines
2.5 KiB
C++

/*
* VHDL abstract syntax elements.
*
* Copyright (C) 2008 Nick Gasson (nick@nickg.me.uk)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef INC_VHDL_ELEMENT_HH
#define INC_VHDL_ELEMENT_HH
#include <iosfwd>
#include <list>
#include <string>
#include <new>
#include <vector>
typedef std::list<std::string> string_list_t;
// Any VHDL syntax element. Each element can also contain a comment.
//
// Memory management is handled specially for vhdl_element subclasses:
// The vast majority of vhdl_elements will be created during code generation
// and persist until after they have been printed, at which point *all*
// vhdl_element objects should be destroyed. To support this all allocations
// of vhdl_element subclasses call a special operator new which records
// the pointer allocated so we can ensure that it is disposed of when
// the code generator completes -- by free_all_objects.
//
// The two big advantages of this are that we don't have to worry about
// memory leaks of vhdl_element objects, and we can freely share pointers
// between different parts of the AST.
class vhdl_element {
public:
virtual ~vhdl_element() {}
void* operator new(size_t size);
void operator delete(void* ptr);
virtual void emit(std::ostream &of, int level=0) const = 0;
void print() const;
void set_comment(std::string comment);
static int free_all_objects();
static size_t total_allocated();
protected:
void emit_comment(std::ostream &of, int level,
bool end_of_line=false) const;
private:
std::string comment_;
static std::vector<vhdl_element*> allocated_;
static size_t total_alloc_;
};
typedef std::list<vhdl_element*> element_list_t;
int indent(int level);
void newline(std::ostream &of, int level);
std::string nl_string(int level);
void blank_line(std::ostream &of, int level);
#endif