misc.c

C++版 词法分析、语法分析器

/* misc - miscellaneous flex routines */

/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Vern Paxson.
 * 
 * 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.
 *
 * Redistribution and use in source and binary forms are permitted provided
 * that: (1) source distributions retain this entire copyright notice and
 * comment, and (2) distributions including binaries display the following
 * acknowledgement:  ``This product includes software developed by the
 * University of California, Berkeley and its contributors'' in the
 * documentation or other materials provided with the distribution and in
 * all advertising materials mentioning features or use of this software.
 * Neither the name of the University nor the names of its contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#ifndef lint
static char rcsid[] =
    "@(#) $Header: c:\\program\040files\\development\\cvs\040repository/flex++/misc.c,v 1.1.1.1 2002/04/13 06:01:32 Bear Exp $ (LBL)";
#endif

#include <ctype.h>
#include "flexdef.h"


/* ANSI C does not guarantee that isascii() is defined */
#ifndef isascii
#define isascii(c) ((c) <= 0177)
#endif



/* declare functions that have forward references */

void dataflush PROTO(());
int otoi PROTO((Char []));



/* allocate_array - allocate memory for an integer array of the given size */

void *allocate_array( size, element_size )
int size, element_size;

    {
    register void *mem;

    /* on 16-bit int machines (e.g., 80286) we might be trying to
     * allocate more than a signed int can hold, and that won't
     * work.  Cheap test:
     */
    if ( element_size * size <= 0 )
        flexfatal( "request for < 1 byte in allocate_array()" );

    mem = (void *) malloc( (unsigned) (element_size * size) );

    if ( mem == NULL )
	flexfatal( "memory allocation failed in allocate_array()" );

    return ( mem );
    }


/* all_lower - true if a string is all lower-case
 *
 * synopsis:
 *    Char *str;
 *    int all_lower();
 *    true/false = all_lower( str );
 */

int all_lower( str )
register Char *str;

    {
    while ( *str )
	{
	if ( ! isascii( *str ) || ! islower( *str ) )
	    return ( 0 );
	++str;
	}

    return ( 1 );
    }


/* all_upper - true if a string is all upper-case
 *
 * synopsis:
 *    Char *str;
 *    int all_upper();
 *    true/false = all_upper( str );
 */

int all_upper( str )
register Char *str;

    {
    while ( *str )
	{
	if ( ! isascii( *str ) || ! isupper( (char) *str ) )
	    return ( 0 );
	++str;
	}

    return ( 1 );
    }


/* bubble - bubble sort an integer array in increasing order
 *
 * synopsis
 *   int v[n], n;
 *   bubble( v, n );
 *
 * description
 *   sorts the first n elements of array v and replaces them in
 *   increasing order.
 *
 * passed
 *   v - the array to be sorted
 *   n - the number of elements of 'v' to be sorted */

void bubble( v, n )
int v[], n;

    {
    register int i, j, k;

    for ( i = n; i > 1; --i )
	for ( j = 1; j < i; ++j )
	    if ( v[j] > v[j + 1] )	/* compare */
		{
		k = v[j];	/* exchange */
		v[j] = v[j + 1];
		v[j + 1] = k;
		}
    }


/* clower - replace upper-case letter to lower-case
 *
 * synopsis:
 *    Char clower();
 *    int c;
 *    c = clower( c );
 */

Char clower( c )
register int c;

    {
    return ( (isascii( c ) && isupper( c )) ? tolower( c ) : c );
    }


/* copy_string - returns a dynamically allocated copy of a string
 *
 * synopsis
 *    char *str, *copy, *copy_string();
 *    copy = copy_string( str );
 */

char *copy_string( str )
register char *str;

    {
    register char *c;
    char *copy;

    /* find length */
    for ( c = str; *c; ++c )
	;

    copy = malloc( (unsigned) ((c - str + 1) * sizeof( char )) );

    if ( copy == NULL )
	flexfatal( "dynamic memory failure in copy_string()" );

    for ( c = copy; (*c++ = *str++); )
	;

    return ( copy );
    }


/* copy_unsigned_string -
 *    returns a dynamically allocated copy of a (potentially) unsigned string
 *
 * synopsis
 *    Char *str, *copy, *copy_unsigned_string();
 *    copy = copy_unsigned_string( str );
 */

Char *copy_unsigned_string( str )
register Char *str;

    {
    register Char *c;
    Char *copy;

    /* find length */
    for ( c = str; *c; ++c )
	;

    copy = (Char *) malloc( (unsigned) ((c - str + 1) * sizeof( Char )) );

    if ( copy == NULL )
	flexfatal( "dynamic memory failure in copy_unsigned_string()" );

    for ( c = copy; (*c++ = *str++); )
	;

    return ( copy );
    }


/* cshell - shell sort a character array in increasing order
 *
 * synopsis
 *
 *   Char v[n];
 *   int n, special_case_0;
 *   cshell( v, n, special_case_0 );
 *
 * description
 *   does a shell sort of the first n elements of array v.
 *   If special_case_0 is true, then any element equal to 0
 *   is instead assumed to have infinite weight.
 *
 * passed
 *   v - array to be sorted
 *   n - number of elements of v to be sorted
 */

void cshell( v, n, special_case_0 )
Char v[];
int n, special_case_0;

    {
    int gap, i, j, jg;
    Char k;

    for ( gap = n / 2; gap > 0; gap = gap / 2 )
	for ( i = gap; i < n; ++i )
	    for ( j = i - gap; j >= 0; j = j - gap )
		{
		jg = j + gap;

		if ( special_case_0 )
		    {
		    if ( v[jg] == 0 )
			break;

		    else if ( v[j] != 0 && v[j] <= v[jg] )
			break;
		    }

		else if ( v[j] <= v[jg] )
		    break;

		k = v[j];
		v[j] = v[jg];
		v[jg] = k;
		}
    }


/* dataend - finish up a block of data declarations
 *
 * synopsis
 *    dataend();
 */

void dataend()

    {
    if ( datapos > 0 )
	dataflush();

    /* add terminator for initialization */
    puts( "    } ;\n" );

    dataline = 0;
    datapos = 0;
    }



/* dataflush - flush generated data statements
 *
 * synopsis
 *    dataflush();
 */

void dataflush()

    {
    putchar( '\n' );

    if ( ++dataline >= NUMDATALINES )
	{
	/* put out a blank line so that the table is grouped into
	 * large blocks that enable the user to find elements easily
	 */
	putchar( '\n' );
	dataline = 0;
	}

    /* reset the number of characters written on the current line */
    datapos = 0;
    }


/* flexerror - report an error message and terminate
 *
 * synopsis
 *    char msg[];
 *    flexerror( msg );
 */

void flexerror( msg )
char msg[];

    {
    fprintf( stderr, "%s: %s\n", program_name, msg );

    flexend( 1 );
    }


/* flexfatal - report a fatal error message and terminate
 *
 * synopsis
 *    char msg[];
 *    flexfatal( msg );
 */

void flexfatal( msg )
char msg[];

    {
    fprintf( stderr, "%s: fatal internal error, %s\n", program_name, msg );
    exit( 1 );
    }


/* flex_gettime - return current time
 *
 * synopsis
 *    char *flex_gettime(), *time_str;
 *    time_str = flex_gettime();
 *
 * note
 *    the routine name has the "flex_" prefix because of name clashes
 *    with Turbo-C
 */

/* include sys/types.h to use time_t and make lint happy */

#ifndef MS_DOS
#ifndef VMS
#include <sys/types.h>
#else
#include <types.h>
#endif
#endif

#ifdef MS_DOS
#include <time.h>
#endif

char *flex_gettime()

    {
    time_t t, time();
    char *result, *ctime(), *copy_string();

    t = time( (long *) 0 );

    result = copy_string( ctime( &t ) );

    /* get rid of trailing newline */
    result[24] = '\0';

    return ( result );
    }


/* lerrif - report an error message formatted with one integer argument
 *
 * synopsis
 *    char msg[];
 *    int arg;
 *    lerrif( msg, arg );
 */

void lerrif( msg, arg )
char msg[];
int arg;

    {
    char errmsg[MAXLINE];
    (void) sprintf( errmsg, msg, arg );
    flexerror( errmsg );
    }


/* lerrsf - report an error message formatted with one string argument
 *
 * synopsis
 *    char msg[], arg[];
 *    lerrsf( msg, arg );
 */

void lerrsf( msg, arg )
char msg[], arg[];

    {
    char errmsg[MAXLINE];

    (void) sprintf( errmsg, msg, arg );
    flexerror( errmsg );
    }


/* htoi - convert a hexadecimal digit string to an integer value
 *
 * synopsis:
 *    int val, htoi();
 *    Char str[];
 *    val = htoi( str );
 */

int htoi( str )
Char str[];

    {
    int result;

    (void) sscanf( (char *) str, "%x", &result );

    return ( result );
    }


/* is_hex_digit - returns true if a character is a valid hex digit, false
 *		  otherwise
 *
 * synopsis:
 *    int true_or_false, is_hex_digit();
 *    int ch;
 *    val = is_hex_digit( ch );
 */