audk/Tools/CCode/Source/Pccts/antlr/hash.c

222 lines
5.5 KiB
C

/*
* hash.c
*
* Manage hash tables.
*
* The following functions are visible:
*
* char *mystrdup(char *); Make space and copy string
* Entry **newHashTable(); Create and return initialized hash table
* Entry *hash_add(Entry **, char *, Entry *)
* Entry *hash_get(Entry **, char *)
*
* SOFTWARE RIGHTS
*
* We reserve no LEGAL rights to the Purdue Compiler Construction Tool
* Set (PCCTS) -- PCCTS is in the public domain. An individual or
* company may do whatever they wish with source code distributed with
* PCCTS or the code generated by PCCTS, including the incorporation of
* PCCTS, or its output, into commerical software.
*
* We encourage users to develop software with PCCTS. However, we do ask
* that credit is given to us for developing PCCTS. By "credit",
* we mean that if you incorporate our source code into one of your
* programs (commercial product, research project, or otherwise) that you
* acknowledge this fact somewhere in the documentation, research report,
* etc... If you like PCCTS and have developed a nice tool with the
* output, please mention that you developed it using PCCTS. In
* addition, we ask that this header remain intact in our source code.
* As long as these guidelines are kept, we expect to continue enhancing
* this system and expect to make other tools available as they are
* completed.
*
* ANTLR 1.33
* Terence Parr
* Parr Research Corporation
* with Purdue University and AHPCRC, University of Minnesota
* 1989-2001
*/
#include <stdio.h>
#include "pcctscfg.h"
#include "hash.h"
#ifdef __USE_PROTOS
#include <stdlib.h>
#else
#ifdef VAXC
#include <stdlib.h>
#else
#include <malloc.h>
#endif
#endif
#include <string.h>
#define StrSame 0
#define fatal(err) \
{fprintf(stderr, "%s(%d):", __FILE__, __LINE__); \
fprintf(stderr, " %s\n", err); exit(PCCTS_EXIT_FAILURE);}
#define require(expr, err) {if ( !(expr) ) fatal(err);}
static unsigned size = HashTableSize;
static char *strings = NULL;
static char *strp;
static unsigned strsize = StrTableSize;
/* create the hash table and string table for terminals (string table only once) */
Entry **
#ifdef __USE_PROTOS
newHashTable( void )
#else
newHashTable( )
#endif
{
Entry **table;
table = (Entry **) calloc(size, sizeof(Entry *));
require( table != NULL, "cannot allocate hash table");
if ( strings == NULL )
{
strings = (char *) calloc(strsize, sizeof(char));
require( strings != NULL, "cannot allocate string table");
strp = strings;
}
return table;
}
void
#ifdef __USE_PROTOS
killHashTable( Entry **table )
#else
killHashTable( table )
Entry **table;
#endif
{
/* for now, just free table, forget entries */
free( (char *) table ); /* MR10 cast */
}
/* Given a table, add 'rec' with key 'key' (add to front of list). return ptr to entry */
Entry *
#ifdef __USE_PROTOS
hash_add( Entry **table, char *key, Entry *rec )
#else
hash_add( table, key, rec )
Entry **table;
char *key;
Entry *rec;
#endif
{
unsigned h=0;
char *p=key;
require(table!=NULL && key!=NULL && rec!=NULL, "add: invalid addition");
Hash(p,h,size);
rec->next = table[h]; /* Add to singly-linked list */
table[h] = rec;
return rec;
}
/* Return ptr to 1st entry found in table under key (return NULL if none found) */
Entry *
#ifdef __USE_PROTOS
hash_get( Entry **table, char *key )
#else
hash_get( table, key )
Entry **table;
char *key;
#endif
{
unsigned h=0;
char *p=key;
Entry *q;
/* require(table!=NULL && key!=NULL, "get: invalid table and/or key");*/
if ( !(table!=NULL && key!=NULL) ) *((char *) 34) = 3;
Hash(p,h,size);
for (q = table[h]; q != NULL; q = q->next)
{
if ( strcmp(key, q->str) == StrSame ) return( q );
}
return( NULL );
}
#ifdef DEBUG_HASH
void
#ifdef __USE_PROTOS
hashStat( Entry **table )
#else
hashStat( table )
Entry **table;
#endif
{
static unsigned short count[20];
int i,n=0,low=0, hi=0;
Entry **p;
float avg=0.0;
for (i=0; i<20; i++) count[i] = 0;
for (p=table; p<&(table[size]); p++)
{
Entry *q = *p;
int len;
if ( q != NULL && low==0 ) low = p-table;
len = 0;
if ( q != NULL ) fprintf(stderr, "[%d]", p-table);
while ( q != NULL )
{
len++;
n++;
fprintf(stderr, " %s", q->str);
q = q->next;
if ( q == NULL ) fprintf(stderr, "\n");
}
count[len]++;
if ( *p != NULL ) hi = p-table;
}
fprintf(stderr, "Storing %d recs used %d hash positions out of %d\n",
n, size-count[0], size);
fprintf(stderr, "%f %% utilization\n",
((float)(size-count[0]))/((float)size));
for (i=0; i<20; i++)
{
if ( count[i] != 0 )
{
avg += (((float)(i*count[i]))/((float)n)) * i;
fprintf(stderr, "Bucket len %d == %d (%f %% of recs)\n",
i, count[i], ((float)(i*count[i]))/((float)n));
}
}
fprintf(stderr, "Avg bucket length %f\n", avg);
fprintf(stderr, "Range of hash function: %d..%d\n", low, hi);
}
#endif
/* Add a string to the string table and return a pointer to it.
* Bump the pointer into the string table to next avail position.
*/
char *
#ifdef __USE_PROTOS
mystrdup( char *s )
#else
mystrdup( s )
char *s;
#endif
{
char *start=strp;
require(s!=NULL, "mystrdup: NULL string");
while ( *s != '\0' )
{
require( strp <= &(strings[strsize-2]),
"string table overflow\nIncrease StrTableSize in hash.h and recompile hash.c\n");
*strp++ = *s++;
}
*strp++ = '\0';
return( start );
}