xref: /freebsd-10.1-release/sys/contrib/ia64/libuwx/src/uwx_str.c

/*
 * Copyright (c) 2002,2003 Hewlett-Packard Company
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

#include "uwx_env.h"
#include "uwx_str.h"

#ifdef _KERNEL
#define	free(p)		/* nullified */
#define	malloc(sz)	NULL
#endif

/*
 *  uwx_str.c
 *
 *  This file contains the routines for maintaining a string
 *  pool for the unwind environment. We preallocate enough
 *  space for most purposes so that no memory allocation is
 *  necessary during a normal unwind. If we do need more,
 *  we use the allocate callback, if one is provided.
 *
 *  The string pool is reused with each call to step(),
 *  and is completely freed when the unwind environment is
 *  freed.
 */


int uwx_init_str_pool(struct uwx_env *env)
{
    if (env->allocate_cb == 0)
	env->string_pool = (struct uwx_str_pool *)
		malloc(sizeof(struct uwx_str_pool));
    else
	env->string_pool = (struct uwx_str_pool *)
		(*env->allocate_cb)(sizeof(struct uwx_str_pool));

    if (env->string_pool == 0)
	return UWX_ERR_NOMEM;

    env->string_pool->next = 0;
    env->string_pool->size = STRPOOLSIZE;
    env->string_pool->used = 0;

    return UWX_OK;
}

void uwx_free_str_pool(struct uwx_env *env)
{
    struct uwx_str_pool *pool;
    struct uwx_str_pool *next;

    for (pool = env->string_pool; pool != 0; pool = next) {
	next = pool->next;
	if (env->free_cb == 0)
	    free(pool);
	else
	    (*env->free_cb)(pool);
    }
}

char *uwx_alloc_str(struct uwx_env *env, char *str)
{
    int len;
    int size;
    struct uwx_str_pool *pool;
    struct uwx_str_pool *prev;
    char *p;

    len = strlen(str) + 1;
    prev = 0;
    for (pool = env->string_pool; pool != 0; pool = pool->next) {
	prev = pool;
	if (pool->size - pool->used >= len)
	    break;
    }
    if (pool == 0) {
	size = STRPOOLSIZE;
	if (len > size)
	    size = len;
	size += sizeof(struct uwx_str_pool) - STRPOOLSIZE;
	if (env->allocate_cb == 0)
	    pool = (struct uwx_str_pool *) malloc(size);
	else
	    pool = (struct uwx_str_pool *) (*env->allocate_cb)(size);
	if (env->string_pool == 0)
	    return 0;
	pool->next = 0;
	pool->size = size;
	pool->used = 0;
	prev->next = pool;
    }
    p = pool->pool + pool->used;
    strcpy(p, str);
    pool->used += len;
    return p;
}

void uwx_reset_str_pool(struct uwx_env *env)
{
    struct uwx_str_pool *pool;

    for (pool = env->string_pool; pool != 0; pool = pool->next)
	pool->used = 0;
}