source: trunk/essentials/sys-devel/flex/misc.c@ 3466

/* 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. */

/*  This file is part of flex. */

/*  Redistribution and use in source and binary forms, with or without */
/*  modification, are permitted provided that the following conditions */
/*  are met: */

/*  1. Redistributions of source code must retain the above copyright */
/*     notice, this list of conditions and the following disclaimer. */
/*  2. Redistributions in binary form must reproduce the above copyright */
/*     notice, this list of conditions and the following disclaimer in the */
/*     documentation and/or other materials provided with the distribution. */

/*  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. */

#include "flexdef.h"
#include "tables.h"

#define CMD_IF_TABLES_SER    "%if-tables-serialization"
#define CMD_TABLES_YYDMAP    "%tables-yydmap"
#define CMD_DEFINE_YYTABLES  "%define-yytables"
#define CMD_IF_CPP_ONLY      "%if-c++-only"
#define CMD_IF_C_ONLY        "%if-c-only"
#define CMD_IF_C_OR_CPP      "%if-c-or-c++"
#define CMD_NOT_FOR_HEADER   "%not-for-header"
#define CMD_OK_FOR_HEADER    "%ok-for-header"
#define CMD_PUSH             "%push"
#define CMD_POP              "%pop"
#define CMD_IF_REENTRANT     "%if-reentrant"
#define CMD_IF_NOT_REENTRANT "%if-not-reentrant"
#define CMD_IF_BISON_BRIDGE  "%if-bison-bridge"
#define CMD_IF_NOT_BISON_BRIDGE  "%if-not-bison-bridge"
#define CMD_ENDIF            "%endif"

/* we allow the skeleton to push and pop. */
struct sko_state {
    bool dc; /**< do_copy */
};
static struct sko_state *sko_stack=0;
static int sko_len=0,sko_sz=0;
static void sko_push(bool dc)
{
    if(!sko_stack){
        sko_sz = 1;
        sko_stack = (struct sko_state*)flex_alloc(sizeof(struct sko_state)*sko_sz);
        sko_len = 0;
    }
    if(sko_len >= sko_sz){
        sko_sz *= 2;
        sko_stack = (struct sko_state*)flex_realloc(sko_stack,sizeof(struct sko_state)*sko_sz);
    }
    
    /* initialize to zero and push */
    sko_stack[sko_len].dc = dc;
    sko_len++;
}
static void sko_peek(bool *dc)
{
    if(sko_len <= 0)
        flex_die("peek attempt when sko stack is empty");
    if(dc)
        *dc = sko_stack[sko_len-1].dc;
}
static void sko_pop(bool* dc)
{
    sko_peek(dc);
    sko_len--;
    if(sko_len < 0)
        flex_die("popped too many times in skeleton.");
}

/* Append "#define defname value\n" to the running buffer. */
void action_define (defname, value)
     const char *defname;
     int value;
{
        char    buf[MAXLINE];
        char   *cpy;

        if ((int) strlen (defname) > MAXLINE / 2) {
                format_pinpoint_message (_
                                         ("name \"%s\" ridiculously long"),
                                         defname);
                return;
        }

        sprintf (buf, "#define %s %d\n", defname, value);
        add_action (buf);

        /* track #defines so we can undef them when we're done. */
        cpy = copy_string (defname);
        buf_append (&defs_buf, &cpy, 1);
}


/** Append "m4_define([[defname]],[[value]])m4_dnl\n" to the running buffer.
 *  @param defname The macro name.
 *  @param value The macro value, can be NULL, which is the same as the empty string.
 */
void action_m4_define (const char *defname, const char * value)
{
        char    buf[MAXLINE];

    flexfatal ("DO NOT USE THIS FUNCTION!");

        if ((int) strlen (defname) > MAXLINE / 2) {
                format_pinpoint_message (_
                                         ("name \"%s\" ridiculously long"),
                                         defname);
                return;
        }

        sprintf (buf, "m4_define([[%s]],[[%s]])m4_dnl\n", defname, value?value:"");
        add_action (buf);
}

/* Append "new_text" to the running buffer. */
void add_action (new_text)
     char   *new_text;
{
        int     len = strlen (new_text);

        while (len + action_index >= action_size - 10 /* slop */ ) {
                int     new_size = action_size * 2;

                if (new_size <= 0)
                        /* Increase just a little, to try to avoid overflow
                         * on 16-bit machines.
                         */
                        action_size += action_size / 8;
                else
                        action_size = new_size;

                action_array =
                        reallocate_character_array (action_array,
                                                    action_size);
        }

        strcpy (&action_array[action_index], new_text);

        action_index += len;
}


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

void   *allocate_array (size, element_size)
     int size;
     size_t element_size;
{
        register void *mem;
        size_t  num_bytes = element_size * size;

        mem = flex_alloc (num_bytes);
        if (!mem)
                flexfatal (_
                           ("memory allocation failed in allocate_array()"));

        return mem;
}


/* all_lower - true if a string is all lower-case */

int all_lower (str)
     register char *str;
{
        while (*str) {
                if (!isascii ((Char) * str) || !islower (*str))
                        return 0;
                ++str;
        }

        return 1;
}


/* all_upper - true if a string is all upper-case */

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

        return 1;
}


/* bubble - bubble sort an integer array in increasing order
 *
 * synopsis
 *   int v[n], n;
 *   void 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;
                        }
}


/* check_char - checks a character to make sure it's within the range
 *              we're expecting.  If not, generates fatal error message
 *              and exits.
 */

void check_char (c)
     int c;
{
        if (c >= CSIZE)
                lerrsf (_("bad character '%s' detected in check_char()"),
                        readable_form (c));

        if (c >= csize)
                lerrsf (_
                        ("scanner requires -8 flag to use the character %s"),
                        readable_form (c));
}



/* clower - replace upper-case letter to lower-case */

Char clower (c)
     register int c;
{
        return (Char) ((isascii (c) && isupper (c)) ? tolower (c) : c);
}


/* copy_string - returns a dynamically allocated copy of a string */

char   *copy_string (str)
     register const char *str;
{
        register const char *c1;
        register char *c2;
        char   *copy;
        unsigned int size;

        /* find length */
        for (c1 = str; *c1; ++c1) ;

        size = (c1 - str + 1) * sizeof (char);

        copy = (char *) flex_alloc (size);

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

        for (c2 = copy; (*c2++ = *str++) != 0;) ;

        return copy;
}


/* copy_unsigned_string -
 *    returns a dynamically allocated copy of a (potentially) unsigned string
 */

Char   *copy_unsigned_string (str)
     register Char *str;
{
        register Char *c;
        Char   *copy;

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

        copy = allocate_Character_array (c - str + 1);

        for (c = copy; (*c++ = *str++) != 0;) ;

        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 */

void dataend ()
{
        /* short circuit any output */
        if (gentables) {

                if (datapos > 0)
                        dataflush ();

                /* add terminator for initialization; { for vi */
                outn ("    } ;\n");
        }
        dataline = 0;
        datapos = 0;
}


/* dataflush - flush generated data statements */

void dataflush ()
{
        /* short circuit any output */
        if (!gentables)
                return;

        outc ('\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.
                 */
                outc ('\n');
                dataline = 0;
        }

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


/* flexerror - report an error message and terminate */

void flexerror (msg)
     const char *msg;
{
        fprintf (stderr, "%s: %s\n", program_name, msg);
        flexend (1);
}


/* flexfatal - report a fatal error message and terminate */

void flexfatal (msg)
     const char *msg;
{
        fprintf (stderr, _("%s: fatal internal error, %s\n"),
                 program_name, msg);
        FLEX_EXIT (1);
}


/* htoi - convert a hexadecimal digit string to an integer value */

int htoi (str)
     Char str[];
{
        unsigned int result;

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

        return result;
}


/* lerrif - report an error message formatted with one integer argument */

void lerrif (msg, arg)
     const char *msg;
     int arg;
{
        char    errmsg[MAXLINE];

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


/* lerrsf - report an error message formatted with one string argument */

void lerrsf (msg, arg)
     const char *msg, arg[];
{
        char    errmsg[MAXLINE];

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


/* line_directive_out - spit out a "#line" statement */

void line_directive_out (output_file, do_infile)
     FILE   *output_file;
     int do_infile;
{
        char    directive[MAXLINE], filename[MAXLINE];
        char   *s1, *s2, *s3;
        static const char *line_fmt = "#line %d \"%s\"\n";

        if (!gen_line_dirs)
                return;

        s1 = do_infile ? infilename : "M4_YY_OUTFILE_NAME";

        if (do_infile && !s1)
        s1 = "<stdin>";
    
        s2 = filename;
        s3 = &filename[sizeof (filename) - 2];

        while (s2 < s3 && *s1) {
                if (*s1 == '\\')
                        /* Escape the '\' */
                        *s2++ = '\\';

                *s2++ = *s1++;
        }

        *s2 = '\0';

        if (do_infile)
                sprintf (directive, line_fmt, linenum, filename);
        else {
                if (output_file == stdout)
                        /* Account for the line directive itself. */
                        ++out_linenum;

                sprintf (directive, line_fmt, out_linenum, filename);
        }

        /* If output_file is nil then we should put the directive in
         * the accumulated actions.
         */
        if (output_file) {
                fputs (directive, output_file);
        }
        else
                add_action (directive);
}


/* mark_defs1 - mark the current position in the action array as
 *               representing where the user's section 1 definitions end
 *               and the prolog begins
 */
void mark_defs1 ()
{
        defs1_offset = 0;
        action_array[action_index++] = '\0';
        action_offset = prolog_offset = action_index;
        action_array[action_index] = '\0';
}


/* mark_prolog - mark the current position in the action array as
 *               representing the end of the action prolog
 */
void mark_prolog ()
{
        action_array[action_index++] = '\0';
        action_offset = action_index;
        action_array[action_index] = '\0';
}


/* mk2data - generate a data statement for a two-dimensional array
 *
 * Generates a data statement initializing the current 2-D array to "value".
 */
void mk2data (value)
     int value;
{
        /* short circuit any output */
        if (!gentables)
                return;

        if (datapos >= NUMDATAITEMS) {
                outc (',');
                dataflush ();
        }

        if (datapos == 0)
                /* Indent. */
                out ("    ");

        else
                outc (',');

        ++datapos;

        out_dec ("%5d", value);
}


/* mkdata - generate a data statement
 *
 * Generates a data statement initializing the current array element to
 * "value".
 */
void mkdata (value)
     int value;
{
        /* short circuit any output */
        if (!gentables)
                return;

        if (datapos >= NUMDATAITEMS) {
                outc (',');
                dataflush ();
        }

        if (datapos == 0)
                /* Indent. */
                out ("    ");
        else
                outc (',');

        ++datapos;

        out_dec ("%5d", value);
}


/* myctoi - return the integer represented by a string of digits */

int myctoi (array)
     const char *array;
{
        int     val = 0;

        (void) sscanf (array, "%d", &val);

        return val;
}


/* myesc - return character corresponding to escape sequence */

Char myesc (array)
     Char array[];
{
        Char    c, esc_char;

        switch (array[1]) {
        case 'b':
                return '\b';
        case 'f':
                return '\f';
        case 'n':
                return '\n';
        case 'r':
                return '\r';
        case 't':
                return '\t';

#if __STDC__
        case 'a':
                return '\a';
        case 'v':
                return '\v';
#else
        case 'a':
                return '\007';
        case 'v':
                return '\013';
#endif

        case '0':
        case '1':
        case '2':
        case '3':
        case '4':
        case '5':
        case '6':
        case '7':
                {               /* \<octal> */
                        int     sptr = 1;

                        while (isascii (array[sptr]) &&
                               isdigit (array[sptr]))
                                /* Don't increment inside loop control
                                 * because if isdigit() is a macro it might
                                 * expand into multiple increments ...
                                 */
                                ++sptr;

                        c = array[sptr];
                        array[sptr] = '\0';

                        esc_char = otoi (array + 1);

                        array[sptr] = c;

                        return esc_char;
                }

        case 'x':
                {               /* \x<hex> */
                        int     sptr = 2;

                        while (isascii (array[sptr]) &&
                               isxdigit ((char) array[sptr]))
                                /* Don't increment inside loop control
                                 * because if isdigit() is a macro it might
                                 * expand into multiple increments ...
                                 */
                                ++sptr;

                        c = array[sptr];
                        array[sptr] = '\0';

                        esc_char = htoi (array + 2);

                        array[sptr] = c;

                        return esc_char;
                }

        default:
                return array[1];
        }
}


/* otoi - convert an octal digit string to an integer value */

int otoi (str)
     Char str[];
{
        unsigned int result;

        (void) sscanf ((char *) str, "%o", &result);
        return result;
}


/* out - various flavors of outputing a (possibly formatted) string for the
 *       generated scanner, keeping track of the line count.
 */

void out (str)
     const char *str;
{
        fputs (str, stdout);
        out_line_count (str);
}

void out_dec (fmt, n)
     const char *fmt;
     int n;
{
        fprintf (stdout, fmt, n);
        out_line_count (fmt);
}

void out_dec2 (fmt, n1, n2)
     const char *fmt;
     int n1, n2;
{
        fprintf (stdout, fmt, n1, n2);
        out_line_count (fmt);
}

void out_hex (fmt, x)
     const char *fmt;
     unsigned int x;
{
        fprintf (stdout, fmt, x);
        out_line_count (fmt);
}

void out_line_count (str)
     const char *str;
{
        register int i;

        for (i = 0; str[i]; ++i)
                if (str[i] == '\n')
                        ++out_linenum;
}

void out_str (fmt, str)
     const char *fmt, str[];
{
        fprintf (stdout,fmt, str);
        out_line_count (fmt);
        out_line_count (str);
}

void out_str3 (fmt, s1, s2, s3)
     const char *fmt, s1[], s2[], s3[];
{
        fprintf (stdout,fmt, s1, s2, s3);
        out_line_count (fmt);
        out_line_count (s1);
        out_line_count (s2);
        out_line_count (s3);
}

void out_str_dec (fmt, str, n)
     const char *fmt, str[];
     int n;
{
        fprintf (stdout,fmt, str, n);
        out_line_count (fmt);
        out_line_count (str);
}

void outc (c)
     int c;
{
        fputc (c, stdout);

        if (c == '\n')
                ++out_linenum;
}

void outn (str)
     const char *str;
{
        fputs (str,stdout);
    fputc('\n',stdout);
        out_line_count (str);
        ++out_linenum;
}

/** Print "m4_define( [[def]], [[val]])m4_dnl\n".
 * @param def The m4 symbol to define.
 * @param val The definition; may be NULL.
 * @return buf
 */
void out_m4_define (const char* def, const char* val)
{
    const char * fmt = "m4_define( [[%s]], [[%s]])m4_dnl\n";
    fprintf(stdout, fmt, def, val?val:"");
}


/* readable_form - return the the human-readable form of a character
 *
 * The returned string is in static storage.
 */

char   *readable_form (c)
     register int c;
{
        static char rform[10];

        if ((c >= 0 && c < 32) || c >= 127) {
                switch (c) {
                case '\b':
                        return "\\b";
                case '\f':
                        return "\\f";
                case '\n':
                        return "\\n";
                case '\r':
                        return "\\r";
                case '\t':
                        return "\\t";

#if __STDC__
                case '\a':
                        return "\\a";
                case '\v':
                        return "\\v";
#endif

                default:
                        (void) sprintf (rform, "\\%.3o", (unsigned int) c);
                        return rform;
                }
        }

        else if (c == ' ')
                return "' '";

        else {
                rform[0] = c;
                rform[1] = '\0';

                return rform;
        }
}


/* reallocate_array - increase the size of a dynamic array */

void   *reallocate_array (array, size, element_size)
     void   *array;
     int size;
     size_t element_size;
{
        register void *new_array;
        size_t  num_bytes = element_size * size;

        new_array = flex_realloc (array, num_bytes);
        if (!new_array)
                flexfatal (_("attempt to increase array size failed"));

        return new_array;
}


/* skelout - write out one section of the skeleton file
 *
 * Description
 *    Copies skelfile or skel array to stdout until a line beginning with
 *    "%%" or EOF is found.
 */
void skelout ()
{
        char    buf_storage[MAXLINE];
        char   *buf = buf_storage;
        bool   do_copy = true;

    /* "reset" the state by clearing the buffer and pushing a '1' */
    if(sko_len > 0)
        sko_peek(&do_copy);
    sko_len = 0;
    sko_push(do_copy=true);


        /* Loop pulling lines either from the skelfile, if we're using
         * one, or from the skel[] array.
         */
        while (skelfile ?
               (fgets (buf, MAXLINE, skelfile) != NULL) :
               ((buf = (char *) skel[skel_ind++]) != 0)) {

                if (skelfile)
                        chomp (buf);

                /* copy from skel array */
                if (buf[0] == '%') {    /* control line */
                        /* print the control line as a comment. */
                        if (ddebug && buf[1] != '#') {
                                if (buf[strlen (buf) - 1] == '\\')
                                        out_str ("/* %s */\\\n", buf);
                                else
                                        out_str ("/* %s */\n", buf);
                        }

                        /* We've been accused of using cryptic markers in the skel.
                         * So we'll use emacs-style-hyphenated-commands.
             * We might consider a hash if this if-else-if-else
             * chain gets too large.
                         */
#define cmd_match(s) (strncmp(buf,(s),strlen(s))==0)

                        if (buf[1] == '%') {
                                /* %% is a break point for skelout() */
                                return;
                        }
            else if (cmd_match (CMD_PUSH)){
                sko_push(do_copy);
                if(ddebug){
                    out_str("/*(state = (%s) */",do_copy?"true":"false");
                }
                out_str("%s\n", buf[strlen (buf) - 1] =='\\' ? "\\" : "");
            }
            else if (cmd_match (CMD_POP)){
                sko_pop(&do_copy);
                if(ddebug){
                    out_str("/*(state = (%s) */",do_copy?"true":"false");
                }
                out_str("%s\n", buf[strlen (buf) - 1] =='\\' ? "\\" : "");
            }
            else if (cmd_match (CMD_IF_REENTRANT)){
                sko_push(do_copy);
                do_copy = reentrant && do_copy;
            }
            else if (cmd_match (CMD_IF_NOT_REENTRANT)){
                sko_push(do_copy);
                do_copy = !reentrant && do_copy;
            }
            else if (cmd_match(CMD_IF_BISON_BRIDGE)){
                sko_push(do_copy);
                do_copy = bison_bridge_lval && do_copy;
            }
            else if (cmd_match(CMD_IF_NOT_BISON_BRIDGE)){
                sko_push(do_copy);
                do_copy = !bison_bridge_lval && do_copy;
            }
            else if (cmd_match (CMD_ENDIF)){
                sko_pop(&do_copy);
            }
                        else if (cmd_match (CMD_IF_TABLES_SER)) {
                do_copy = do_copy && tablesext;
                        }
                        else if (cmd_match (CMD_TABLES_YYDMAP)) {
                                if (tablesext && yydmap_buf.elts)
                                        outn ((char *) (yydmap_buf.elts));
                        }
            else if (cmd_match (CMD_DEFINE_YYTABLES)) {
                out_str("#define YYTABLES_NAME \"%s\"\n",
                        tablesname?tablesname:"yytables");
            }
                        else if (cmd_match (CMD_IF_CPP_ONLY)) {
                                /* only for C++ */
                sko_push(do_copy);
                                do_copy = C_plus_plus;
                        }
                        else if (cmd_match (CMD_IF_C_ONLY)) {
                                /* %- only for C */
                sko_push(do_copy);
                                do_copy = !C_plus_plus;
                        }
                        else if (cmd_match (CMD_IF_C_OR_CPP)) {
                                /* %* for C and C++ */
                sko_push(do_copy);
                                do_copy = true;
                        }
                        else if (cmd_match (CMD_NOT_FOR_HEADER)) {
                                /* %c begin linkage-only (non-header) code. */
                                OUT_BEGIN_CODE ();
                        }
                        else if (cmd_match (CMD_OK_FOR_HEADER)) {
                                /* %e end linkage-only code. */
                                OUT_END_CODE ();
                        }
                        else if (buf[1] == '#') {
                                /* %# a comment in the skel. ignore. */
                        }
                        else {
                                flexfatal (_("bad line in skeleton file"));
                        }
                }

                else if (do_copy) 
            outn (buf);
        }                       /* end while */
}


/* transition_struct_out - output a yy_trans_info structure
 *
 * outputs the yy_trans_info structure with the two elements, element_v and
 * element_n.  Formats the output with spaces and carriage returns.
 */

void transition_struct_out (element_v, element_n)
     int element_v, element_n;
{

        /* short circuit any output */
        if (!gentables)
                return;

        out_dec2 (" {%4d,%4d },", element_v, element_n);

        datapos += TRANS_STRUCT_PRINT_LENGTH;

        if (datapos >= 79 - TRANS_STRUCT_PRINT_LENGTH) {
                outc ('\n');

                if (++dataline % 10 == 0)
                        outc ('\n');

                datapos = 0;
        }
}


/* The following is only needed when building flex's parser using certain
 * broken versions of bison.
 */
void   *yy_flex_xmalloc (size)
     int size;
{
        void   *result = flex_alloc ((size_t) size);

        if (!result)
                flexfatal (_
                           ("memory allocation failed in yy_flex_xmalloc()"));

        return result;
}


/* zero_out - set a region of memory to 0
 *
 * Sets region_ptr[0] through region_ptr[size_in_bytes - 1] to zero.
 */

void zero_out (region_ptr, size_in_bytes)
     char   *region_ptr;
     size_t size_in_bytes;
{
        register char *rp, *rp_end;

        rp = region_ptr;
        rp_end = region_ptr + size_in_bytes;

        while (rp < rp_end)
                *rp++ = 0;
}

/* Remove all '\n' and '\r' characters, if any, from the end of str.
 * str can be any null-terminated string, or NULL.
 * returns str. */
char   *chomp (str)
     char   *str;
{
        char   *p = str;

        if (!str || !*str)      /* s is null or empty string */
                return str;

        /* find end of string minus one */
        while (*p)
                ++p;
        --p;

        /* eat newlines */
        while (p >= str && (*p == '\r' || *p == '\n'))
                *p-- = 0;
        return str;
}