From 91b6eb1140eda6bab324821ee3785e5d0ca155b8 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Fri, 2 Jun 2017 11:59:28 +0200 Subject: Add internal facility for dynamic array handling This is intended as a type-safe alternative to obstacks and hand-written realloc constructs. The implementation avoids writing function pointers to the heap. --- malloc/dynarray_finalize.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) create mode 100644 malloc/dynarray_finalize.c (limited to 'malloc/dynarray_finalize.c') diff --git a/malloc/dynarray_finalize.c b/malloc/dynarray_finalize.c new file mode 100644 index 0000000000..6dd8705382 --- /dev/null +++ b/malloc/dynarray_finalize.c @@ -0,0 +1,62 @@ +/* Copy the dynamically-allocated area to an explicitly-sized heap allocation. + Copyright (C) 2017 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 + . */ + +#include +#include +#include + +bool +__libc_dynarray_finalize (struct dynarray_header *list, + void *scratch, size_t element_size, + struct dynarray_finalize_result *result) +{ + if (__dynarray_error (list)) + /* The caller will reported the deferred error. */ + return false; + + size_t used = list->used; + + /* Empty list. */ + if (used == 0) + { + /* An empty list could still be backed by a heap-allocated + array. Free it if necessary. */ + if (list->array != scratch) + free (list->array); + *result = (struct dynarray_finalize_result) { NULL, 0 }; + return true; + } + + size_t allocation_size = used * element_size; + void *heap_array = malloc (allocation_size); + if (heap_array != NULL) + { + /* The new array takes ownership of the strings. */ + if (list->array != NULL) + memcpy (heap_array, list->array, allocation_size); + if (list->array != scratch) + free (list->array); + *result = (struct dynarray_finalize_result) + { .array = heap_array, .length = used }; + return true; + } + else + /* The caller will perform the freeing operation. */ + return false; +} +libc_hidden_def (__libc_dynarray_finalize) -- cgit v1.2.3-70-g09d2