source: vendor/flex/2.5.33/buf.c

/* flex - tool to generate fast lexical analyzers */

/*  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"

/* Take note: The buffer object is sometimes used as a String buffer (one
 * continuous string), and sometimes used as a list of strings, usually line by
 * line.
 * 
 * The type is specified in buf_init by the elt_size. If the elt_size is
 * sizeof(char), then the buffer should be treated as string buffer. If the
 * elt_size is sizeof(char*), then the buffer should be treated as a list of
 * strings.
 *
 * Certain functions are only appropriate for one type or the other. 
 */

/* global buffers. */
struct Buf userdef_buf;         /**< for user #definitions triggered by cmd-line. */
struct Buf defs_buf;            /**< for #define's autogenerated. List of strings. */
struct Buf yydmap_buf;          /**< string buffer to hold yydmap elements */
struct Buf m4defs_buf;          /**< m4 definitions. List of strings. */
struct Buf top_buf;             /**< contains %top code. String buffer. */

struct Buf *buf_print_strings(struct Buf * buf, FILE* out)
{
    int i;

    if(!buf || !out)
        return buf;

    for (i=0; i < buf->nelts; i++){
        const char * s = ((char**)buf->elts)[i];
        if(s)
            fprintf(out, "%s", s);
    }
    return buf;
}

/* Append a "%s" formatted string to a string buffer */
struct Buf *buf_prints (struct Buf *buf, const char *fmt, const char *s)
{
        char   *t;

        t = flex_alloc (strlen (fmt) + strlen (s) + 1);
        sprintf (t, fmt, s);
        buf = buf_strappend (buf, t);
        flex_free (t);
        return buf;
}

/** Append a line directive to the string buffer.
 * @param buf A string buffer.
 * @param filename file name
 * @param lineno line number
 * @return buf
 */
struct Buf *buf_linedir (struct Buf *buf, const char* filename, int lineno)
{
    char   *t, *fmt = "#line %d \"%s\"\n";
    
    t = flex_alloc (strlen (fmt) + strlen (filename) + (int)(1 + log10(lineno>=0?lineno:-lineno)) + 1);
    sprintf (t, fmt, lineno, filename);
    buf = buf_strappend (buf, t);
    flex_free (t);
    return buf;
}


/** Append the contents of @a src to @a dest.
 * @param @a dest the destination buffer
 * @param @a dest the source buffer
 * @return @a dest
 */
struct Buf *buf_concat(struct Buf* dest, const struct Buf* src)
{
    buf_append(dest, src->elts, src->nelts);
    return dest;
}


/* Appends n characters in str to buf. */
struct Buf *buf_strnappend (buf, str, n)
     struct Buf *buf;
     const char *str;
     int n;
{
        buf_append (buf, str, n + 1);

        /* "undo" the '\0' character that buf_append() already copied. */
        buf->nelts--;

        return buf;
}

/* Appends characters in str to buf. */
struct Buf *buf_strappend (buf, str)
     struct Buf *buf;
     const char *str;
{
        return buf_strnappend (buf, str, strlen (str));
}

/* appends "#define str def\n" */
struct Buf *buf_strdefine (buf, str, def)
     struct Buf *buf;
     const char *str;
     const char *def;
{
        buf_strappend (buf, "#define ");
        buf_strappend (buf, " ");
        buf_strappend (buf, str);
        buf_strappend (buf, " ");
        buf_strappend (buf, def);
        buf_strappend (buf, "\n");
        return buf;
}

/** Pushes "m4_define( [[def]], [[val]])m4_dnl" to end of buffer.
 * @param buf A buffer as a list of strings.
 * @param def The m4 symbol to define.
 * @param val The definition; may be NULL.
 * @return buf
 */
struct Buf *buf_m4_define (struct Buf *buf, const char* def, const char* val)
{
    const char * fmt = "m4_define( [[%s]], [[%s]])m4_dnl\n";
    char * str;

    val = val?val:"";
    str = (char*)flex_alloc(strlen(fmt) + strlen(def) + strlen(val) + 2);

    sprintf(str, fmt, def, val);
    buf_append(buf, &str, 1);
    return buf;
}

/** Pushes "m4_undefine([[def]])m4_dnl" to end of buffer.
 * @param buf A buffer as a list of strings.
 * @param def The m4 symbol to undefine.
 * @return buf
 */
struct Buf *buf_m4_undefine (struct Buf *buf, const char* def)
{
    const char * fmt = "m4_undefine( [[%s]])m4_dnl\n";
    char * str;

    str = (char*)flex_alloc(strlen(fmt) + strlen(def) + 2);

    sprintf(str, fmt, def);
    buf_append(buf, &str, 1);
    return buf;
}

/* create buf with 0 elements, each of size elem_size. */
void buf_init (buf, elem_size)
     struct Buf *buf;
     size_t elem_size;
{
        buf->elts = (void *) 0;
        buf->nelts = 0;
        buf->elt_size = elem_size;
        buf->nmax = 0;
}

/* frees memory */
void buf_destroy (buf)
     struct Buf *buf;
{
        if (buf && buf->elts)
                flex_free (buf->elts);
        buf->elts = (void *) 0;
}


/* appends ptr[] to buf, grow if necessary.
 * n_elem is number of elements in ptr[], NOT bytes.
 * returns buf.
 * We grow by mod(512) boundaries.
 */

struct Buf *buf_append (buf, ptr, n_elem)
     struct Buf *buf;
     const void *ptr;
     int n_elem;
{
        int     n_alloc = 0;

        if (!ptr || n_elem == 0)
                return buf;

        /* May need to alloc more. */
        if (n_elem + buf->nelts > buf->nmax) {

                /* exact amount needed... */
                n_alloc = (n_elem + buf->nelts) * buf->elt_size;

                /* ...plus some extra */
                if (((n_alloc * buf->elt_size) % 512) != 0
                    && buf->elt_size < 512)
                        n_alloc +=
                                (512 -
                                 ((n_alloc * buf->elt_size) % 512)) /
                                buf->elt_size;

                if (!buf->elts)
                        buf->elts =
                                allocate_array (n_alloc, buf->elt_size);
                else
                        buf->elts =
                                reallocate_array (buf->elts, n_alloc,
                                                  buf->elt_size);

                buf->nmax = n_alloc;
        }

        memcpy ((char *) buf->elts + buf->nelts * buf->elt_size, ptr,
                n_elem * buf->elt_size);
        buf->nelts += n_elem;

        return buf;
}

/* vim:set tabstop=8 softtabstop=4 shiftwidth=4: */