curl/lib/curlx/strdup.c
Viktor Szakats 31a4f415af
build: tidy up and dedupe strdup functions
- de-dupe lib/src strdup/memdup functions into curlx.
- introduce `CURLX_STRDUP_LOW()` for mapping `strdup()`, and to do it at
  one place within the code, in `curl_setup.h`.
- tests/server: use `curlx_strdup()`. (Also to fix building without
  a system `strdup()`.)
- curlx/curlx.h: shorten and tidy up.
- adjust Windows build path to not need `HAVE_STRDUP`.
- build: stop detecting `HAVE_STRDUP` on Windows.

Closes #20497
2026-02-03 14:02:30 +01:00

137 lines
3.9 KiB
C

/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
* SPDX-License-Identifier: curl
*
***************************************************************************/
#include "../curl_setup.h"
#ifdef _WIN32
#include <wchar.h>
#endif
#include "strdup.h"
#ifdef _WIN32
/***************************************************************************
*
* curlx_wcsdup(source)
*
* Copies the 'source' wchar string to a newly allocated buffer (that is
* returned). Used by macro curlx_tcsdup().
*
* Returns the new pointer or NULL on failure.
*
***************************************************************************/
wchar_t *curlx_wcsdup(const wchar_t *src)
{
size_t length = wcslen(src);
if(length > (SIZE_MAX / sizeof(wchar_t)) - 1)
return (wchar_t *)NULL; /* integer overflow */
return (wchar_t *)curlx_memdup(src, (length + 1) * sizeof(wchar_t));
}
#elif !defined(HAVE_STRDUP)
char *curlx_strdup_low(const char *str)
{
size_t len;
char *newstr;
if(!str)
return NULL;
len = strlen(str) + 1;
newstr = curlx_malloc(len);
if(!newstr)
return NULL;
memcpy(newstr, str, len);
return newstr;
}
#endif
/***************************************************************************
*
* curlx_memdup(source, length)
*
* Copies the 'source' data to a newly allocated buffer (that is
* returned). Copies 'length' bytes.
*
* Returns the new pointer or NULL on failure.
*
***************************************************************************/
void *curlx_memdup(const void *src, size_t length)
{
void *buffer = curlx_malloc(length);
if(!buffer)
return NULL; /* fail */
memcpy(buffer, src, length);
return buffer;
}
/***************************************************************************
*
* curlx_memdup0(source, length)
*
* Copies the 'source' string to a newly allocated buffer (that is returned).
* Copies 'length' bytes then adds a null-terminator.
*
* Returns the new pointer or NULL on failure.
*
***************************************************************************/
void *curlx_memdup0(const char *src, size_t length)
{
char *buf = (length < SIZE_MAX) ? curlx_malloc(length + 1) : NULL;
if(!buf)
return NULL;
if(length) {
DEBUGASSERT(src); /* must never be NULL */
memcpy(buf, src, length);
}
buf[length] = 0;
return buf;
}
/***************************************************************************
*
* curlx_saferealloc(ptr, size)
*
* Does a normal curlx_realloc(), but will free the data pointer if the realloc
* fails. If 'size' is non-zero, it will free the data and return a failure.
*
* This convenience function is provided and used to help us avoid a common
* mistake pattern when we could pass in a zero, catch the NULL return and end
* up free'ing the memory twice.
*
* Returns the new pointer or NULL on failure.
*
***************************************************************************/
void *curlx_saferealloc(void *ptr, size_t size)
{
void *datap = curlx_realloc(ptr, size);
if(size && !datap)
/* only free 'ptr' if size was non-zero */
curlx_free(ptr);
return datap;
}