| /* Variable-sized buffer with on-stack default allocation. |
| Copyright (C) 2015-2018 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #ifndef _LIBC |
| # include <libc-config.h> |
| #endif |
| |
| #include <scratch_buffer.h> |
| #include <errno.h> |
| #include <limits.h> |
| |
| bool |
| __libc_scratch_buffer_set_array_size (struct scratch_buffer *buffer, |
| size_t nelem, size_t size) |
| { |
| size_t new_length = nelem * size; |
| |
| /* Avoid overflow check if both values are small. */ |
| if ((nelem | size) >> (sizeof (size_t) * CHAR_BIT / 2) != 0 |
| && nelem != 0 && size != new_length / nelem) |
| { |
| /* Overflow. Discard the old buffer, but it must remain valid |
| to free. */ |
| scratch_buffer_free (buffer); |
| scratch_buffer_init (buffer); |
| __set_errno (ENOMEM); |
| return false; |
| } |
| |
| if (new_length <= buffer->length) |
| return true; |
| |
| /* Discard old buffer. */ |
| scratch_buffer_free (buffer); |
| |
| char *new_ptr = malloc (new_length); |
| if (new_ptr == NULL) |
| { |
| /* Buffer must remain valid to free. */ |
| scratch_buffer_init (buffer); |
| return false; |
| } |
| |
| /* Install new heap-based buffer. */ |
| buffer->data = new_ptr; |
| buffer->length = new_length; |
| return true; |
| } |
| libc_hidden_def (__libc_scratch_buffer_set_array_size) |