78 lines
2.7 KiB
C
78 lines
2.7 KiB
C
#ifndef __symbols_H
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#define __symbols_H
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/*
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* Copyright (c) 2001-2010 Stephen Williams (steve@icarus.com)
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*
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* This source code is free software; you can redistribute it
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* and/or modify it in source code form under the terms of the GNU
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* General Public License as published by the Free Software
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* Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
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*/
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/*
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* The symbol_table_t is intended as a means to hold and quickly index
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* large symbol tables with small symbol values. That is, the value
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* should fit in a 32bit unsigned integer (not even necessarily a
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* pointer.)
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*
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* The key is an unstructured ASCII string, terminated by a
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* null. Items added to the table are not removed, unless the entire
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* table is deleted.
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*
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* The compiler uses symbol tables to help match up operands to
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* referenced objects in the source. The compiler knows by the context
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* that the symbol appears what kind of thing is referenced, and so
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* what symbol table to look in.
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*/
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# include "config.h"
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/*
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* This is the basic type of a symbol table. It is opaque. Don't even
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* try to look inside. The actual implementation is given in the
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* symbols.cc source file.
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*/
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typedef struct symbol_table_s *symbol_table_t;
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typedef struct symbol_value_s {
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union {
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unsigned long num;
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void*ptr;
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};
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} symbol_value_t;
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/*
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* Create a new symbol table or release an existing one. A new symbol
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* table has no keys and no values. As a symbol table is built up, it
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* consumes more and more memory. When the table is no longer needed,
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* the delete_symbol_table method will delete the table, including all
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* the space for the keys.
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*/
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extern symbol_table_t new_symbol_table(void);
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extern void delete_symbol_table(symbol_table_t tbl);
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/*
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* This method locates the value in the symbol table and sets its
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* value. If the key doesn't yet exist, create it.
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*/
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void sym_set_value(symbol_table_t tbl, const char*key, symbol_value_t val);
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/*
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* This method locates the value in the symbol table and returns
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* it. If the value does not exist, create it, initialize it with
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* zero and return the zero value.
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*/
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symbol_value_t sym_get_value(symbol_table_t tbl, const char*key);
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#endif
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