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Flex2
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sym.c
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C/C++ Source or Header
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1988-10-02
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6KB
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284 lines
/* sym - symbol table routines */
/*
* Copyright (c) 1987, the University of California
*
* The United States Government has rights in this work pursuant to
* contract no. DE-AC03-76SF00098 between the United States Department of
* Energy and the University of California.
*
* This program may be redistributed. Enhancements and derivative works
* may be created provided the new works, if made available to the general
* public, are made available for use by anyone.
*/
#include "flexdef.h"
struct hash_entry *ndtbl[NAME_TABLE_HASH_SIZE];
struct hash_entry *sctbl[START_COND_HASH_SIZE];
struct hash_entry *ccltab[CCL_HASH_SIZE];
struct hash_entry *findsym();
/* addsym - add symbol and definitions to symbol table
*
* synopsis
* char sym[], *str_def;
* int int_def;
* hash_table table;
* int table_size;
* 0 / -1 = addsym( sym, def, int_def, table, table_size );
*
* -1 is returned if the symbol already exists, and the change not made.
*/
int addsym( sym, str_def, int_def, table, table_size )
register char sym[];
char *str_def;
int int_def;
hash_table table;
int table_size;
{
int hash_val = hashfunct( sym, table_size );
register struct hash_entry *entry = table[hash_val];
register struct hash_entry *new_entry;
register struct hash_entry *successor;
char *malloc();
while ( entry )
{
if ( ! strcmp( sym, entry->name ) )
{ /* entry already exists */
return ( -1 );
}
entry = entry->next;
}
/* create new entry */
new_entry = (struct hash_entry *) malloc( sizeof( struct hash_entry ) );
if ( new_entry == NULL )
flexfatal( "symbol table memory allocation failed" );
if ( (successor = table[hash_val]) )
{
new_entry->next = successor;
successor->prev = new_entry;
}
else
new_entry->next = NULL;
new_entry->prev = NULL;
new_entry->name = sym;
new_entry->str_val = str_def;
new_entry->int_val = int_def;
table[hash_val] = new_entry;
return ( 0 );
}
/* cclinstal - save the text of a character class
*
* synopsis
* char ccltxt[];
* int cclnum;
* cclinstal( ccltxt, cclnum );
*/
cclinstal( ccltxt, cclnum )
char ccltxt[];
int cclnum;
{
/* we don't bother checking the return status because we are not called
* unless the symbol is new
*/
char *copy_string();
(void) addsym( copy_string( ccltxt ), (char *) 0, cclnum,
ccltab, CCL_HASH_SIZE );
}
/* ccllookup - lookup the number associated with character class text
*
* synopsis
* char ccltxt[];
* int ccllookup, cclval;
* cclval/0 = ccllookup( ccltxt );
*/
int ccllookup( ccltxt )
char ccltxt[];
{
return ( findsym( ccltxt, ccltab, CCL_HASH_SIZE )->int_val );
}
/* findsym - find symbol in symbol table
*
* synopsis
* char sym[];
* hash_table table;
* int table_size;
* struct hash_entry *entry, *findsym();
* entry = findsym( sym, table, table_size );
*/
struct hash_entry *findsym( sym, table, table_size )
register char sym[];
hash_table table;
int table_size;
{
register struct hash_entry *entry = table[hashfunct( sym, table_size )];
static struct hash_entry empty_entry =
{
(struct hash_entry *) 0, (struct hash_entry *) 0, NULL, NULL, 0,
} ;
while ( entry )
{
if ( ! strcmp( sym, entry->name ) )
return ( entry );
entry = entry->next;
}
return ( &empty_entry );
}
/* hashfunct - compute the hash value for "str" and hash size "hash_size"
*
* synopsis
* char str[];
* int hash_size, hash_val;
* hash_val = hashfunct( str, hash_size );
*/
int hashfunct( str, hash_size )
register char str[];
int hash_size;
{
register int hashval;
register int locstr;
hashval = 0;
locstr = 0;
while ( str[locstr] )
hashval = ((hashval << 1) + str[locstr++]) % hash_size;
return ( hashval );
}
/* ndinstal - install a name definition
*
* synopsis
* char nd[], def[];
* ndinstal( nd, def );
*/
ndinstal( nd, def )
char nd[], def[];
{
char *copy_string();
if ( addsym( copy_string( nd ), copy_string( def ), 0,
ndtbl, NAME_TABLE_HASH_SIZE ) )
synerr( "name defined twice" );
}
/* ndlookup - lookup a name definition
*
* synopsis
* char nd[], *def;
* char *ndlookup();
* def/NULL = ndlookup( nd );
*/
char *ndlookup( nd )
char nd[];
{
return ( findsym( nd, ndtbl, NAME_TABLE_HASH_SIZE )->str_val );
}
/* scinstal - make a start condition
*
* synopsis
* char str[];
* int xcluflg;
* scinstal( str, xcluflg );
*
* NOTE
* the start condition is Exclusive if xcluflg is true
*/
scinstal( str, xcluflg )
char str[];
int xcluflg;
{
char *copy_string();
/* bit of a hack. We know how the default start-condition is
* declared, and don't put out a define for it, because it
* would come out as "#define 0 1"
*/
/* actually, this is no longer the case. The default start-condition
* is now called "INITIAL". But we keep the following for the sake
* of future robustness.
*/
if ( strcmp( str, "0" ) )
printf( "#define %s %d\n", str, lastsc * 2 );
if ( ++lastsc >= current_max_scs )
{
current_max_scs += MAX_SCS_INCREMENT;
++num_reallocs;
scset = reallocate_integer_array( scset, current_max_scs );
scbol = reallocate_integer_array( scbol, current_max_scs );
scxclu = reallocate_integer_array( scxclu, current_max_scs );
actvsc = reallocate_integer_array( actvsc, current_max_scs );
}
if ( addsym( copy_string( str ), (char *) 0, lastsc,
sctbl, START_COND_HASH_SIZE ) )
lerrsf( "start condition %s declared twice", str );
scset[lastsc] = mkstate( SYM_EPSILON );
scbol[lastsc] = mkstate( SYM_EPSILON );
scxclu[lastsc] = xcluflg;
}
/* sclookup - lookup the number associated with a start condition
*
* synopsis
* char str[], scnum;
* int sclookup;
* scnum/0 = sclookup( str );
*/
int sclookup( str )
char str[];
{
return ( findsym( str, sctbl, START_COND_HASH_SIZE )->int_val );
}