Mercurial > gnulib
changeset 38788:4ab29e71a399
scratch_buffer: don’t use private glibc API
Suggested by Florian Weimer in:
http://lists.gnu.org/archive/html/bug-gnulib/2017-09/msg00004.html
* lib/scratch_buffer.h: Rename to lib/malloc/scratch_buffer.h.
* lib/scratch_buffer_grow.c: Rename to
lib/malloc/scratch_buffer_grow.c.
* lib/scratch_buffer_grow_preserve.c: Rename to
lib/malloc/scratch_buffer_grow_preserve.c.
* lib/scratch_buffer_set_array_size.c: Rename to
lib/malloc/scratch_buffer_set_array_size.c.
* lib/scratch_buffer.h: New file.
* modules/scratch_buffer (Files, Makefile.am):
Adjust to source-file renaming.
| author | Paul Eggert <eggert@cs.ucla.edu> |
|---|---|
| date | Sat, 02 Sep 2017 01:21:03 -0700 |
| parents | cb06f3f85d7e |
| children | e10a13f4a072 |
| files | ChangeLog lib/malloc/scratch_buffer.h lib/malloc/scratch_buffer_grow.c lib/malloc/scratch_buffer_grow_preserve.c lib/malloc/scratch_buffer_set_array_size.c lib/scratch_buffer.h lib/scratch_buffer_grow.c lib/scratch_buffer_grow_preserve.c lib/scratch_buffer_set_array_size.c modules/scratch_buffer |
| diffstat | 10 files changed, 349 insertions(+), 331 deletions(-) [+] |
line wrap: on
line diff
--- a/ChangeLog Fri Sep 01 15:41:45 2017 -0700 +++ b/ChangeLog Sat Sep 02 01:21:03 2017 -0700 @@ -1,3 +1,19 @@ +2017-09-02 Paul Eggert <eggert@cs.ucla.edu> + + scratch_buffer: don’t use private glibc API + Suggested by Florian Weimer in: + http://lists.gnu.org/archive/html/bug-gnulib/2017-09/msg00004.html + * lib/scratch_buffer.h: Rename to lib/malloc/scratch_buffer.h. + * lib/scratch_buffer_grow.c: Rename to + lib/malloc/scratch_buffer_grow.c. + * lib/scratch_buffer_grow_preserve.c: Rename to + lib/malloc/scratch_buffer_grow_preserve.c. + * lib/scratch_buffer_set_array_size.c: Rename to + lib/malloc/scratch_buffer_set_array_size.c. + * lib/scratch_buffer.h: New file. + * modules/scratch_buffer (Files, Makefile.am): + Adjust to source-file renaming. + 2017-09-01 Paul Eggert <eggert@cs.ucla.edu> glob: use scratch_buffer instead of extend_alloca
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/lib/malloc/scratch_buffer.h Sat Sep 02 01:21:03 2017 -0700 @@ -0,0 +1,135 @@ +/* Variable-sized buffer with on-stack default allocation. + Copyright (C) 2015-2017 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 + <http://www.gnu.org/licenses/>. */ + +#ifndef _SCRATCH_BUFFER_H +#define _SCRATCH_BUFFER_H + +/* Scratch buffers with a default stack allocation and fallback to + heap allocation. It is expected that this function is used in this + way: + + struct scratch_buffer tmpbuf; + scratch_buffer_init (&tmpbuf); + + while (!function_that_uses_buffer (tmpbuf.data, tmpbuf.length)) + if (!scratch_buffer_grow (&tmpbuf)) + return -1; + + scratch_buffer_free (&tmpbuf); + return 0; + + The allocation functions (scratch_buffer_grow, + scratch_buffer_grow_preserve, scratch_buffer_set_array_size) make + sure that the heap allocation, if any, is freed, so that the code + above does not have a memory leak. The buffer still remains in a + state that can be deallocated using scratch_buffer_free, so a loop + like this is valid as well: + + struct scratch_buffer tmpbuf; + scratch_buffer_init (&tmpbuf); + + while (!function_that_uses_buffer (tmpbuf.data, tmpbuf.length)) + if (!scratch_buffer_grow (&tmpbuf)) + break; + + scratch_buffer_free (&tmpbuf); + + scratch_buffer_grow and scratch_buffer_grow_preserve are guaranteed + to grow the buffer by at least 512 bytes. This means that when + using the scratch buffer as a backing store for a non-character + array whose element size, in bytes, is 512 or smaller, the scratch + buffer only has to grow once to make room for at least one more + element. +*/ + +#include <stdbool.h> +#include <stddef.h> +#include <stdlib.h> + +/* Scratch buffer. Must be initialized with scratch_buffer_init + before its use. */ +struct scratch_buffer { + void *data; /* Pointer to the beginning of the scratch area. */ + size_t length; /* Allocated space at the data pointer, in bytes. */ + max_align_t __space[(1023 + sizeof (max_align_t)) / sizeof (max_align_t)]; +}; + +/* Initializes *BUFFER so that BUFFER->data points to BUFFER->__space + and BUFFER->length reflects the available space. */ +static inline void +scratch_buffer_init (struct scratch_buffer *buffer) +{ + buffer->data = buffer->__space; + buffer->length = sizeof (buffer->__space); +} + +/* Deallocates *BUFFER (if it was heap-allocated). */ +static inline void +scratch_buffer_free (struct scratch_buffer *buffer) +{ + if (buffer->data != buffer->__space) + free (buffer->data); +} + +/* Grow *BUFFER by some arbitrary amount. The buffer contents is NOT + preserved. Return true on success, false on allocation failure (in + which case the old buffer is freed). On success, the new buffer is + larger than the previous size. On failure, *BUFFER is deallocated, + but remains in a free-able state, and errno is set. */ +bool __libc_scratch_buffer_grow (struct scratch_buffer *buffer); +libc_hidden_proto (__libc_scratch_buffer_grow) + +/* Alias for __libc_scratch_buffer_grow. */ +static __always_inline bool +scratch_buffer_grow (struct scratch_buffer *buffer) +{ + return __glibc_likely (__libc_scratch_buffer_grow (buffer)); +} + +/* Like __libc_scratch_buffer_grow, but preserve the old buffer + contents on success, as a prefix of the new buffer. */ +bool __libc_scratch_buffer_grow_preserve (struct scratch_buffer *buffer); +libc_hidden_proto (__libc_scratch_buffer_grow_preserve) + +/* Alias for __libc_scratch_buffer_grow_preserve. */ +static __always_inline bool +scratch_buffer_grow_preserve (struct scratch_buffer *buffer) +{ + return __glibc_likely (__libc_scratch_buffer_grow_preserve (buffer)); +} + +/* Grow *BUFFER so that it can store at least NELEM elements of SIZE + bytes. The buffer contents are NOT preserved. Both NELEM and SIZE + can be zero. Return true on success, false on allocation failure + (in which case the old buffer is freed, but *BUFFER remains in a + free-able state, and errno is set). It is unspecified whether this + function can reduce the array size. */ +bool __libc_scratch_buffer_set_array_size (struct scratch_buffer *buffer, + size_t nelem, size_t size); +libc_hidden_proto (__libc_scratch_buffer_set_array_size) + +/* Alias for __libc_scratch_set_array_size. */ +static __always_inline bool +scratch_buffer_set_array_size (struct scratch_buffer *buffer, + size_t nelem, size_t size) +{ + return __glibc_likely (__libc_scratch_buffer_set_array_size + (buffer, nelem, size)); +} + +#endif /* _SCRATCH_BUFFER_H */
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/lib/malloc/scratch_buffer_grow.c Sat Sep 02 01:21:03 2017 -0700 @@ -0,0 +1,56 @@ +/* Variable-sized buffer with on-stack default allocation. + Copyright (C) 2015-2017 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 + <http://www.gnu.org/licenses/>. */ + +#ifndef _LIBC +# include <libc-config.h> +#endif + +#include <scratch_buffer.h> +#include <errno.h> + +bool +__libc_scratch_buffer_grow (struct scratch_buffer *buffer) +{ + void *new_ptr; + size_t new_length = buffer->length * 2; + + /* Discard old buffer. */ + scratch_buffer_free (buffer); + + /* Check for overflow. */ + if (__glibc_likely (new_length >= buffer->length)) + new_ptr = malloc (new_length); + else + { + __set_errno (ENOMEM); + new_ptr = NULL; + } + + if (__glibc_unlikely (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_grow)
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/lib/malloc/scratch_buffer_grow_preserve.c Sat Sep 02 01:21:03 2017 -0700 @@ -0,0 +1,67 @@ +/* Variable-sized buffer with on-stack default allocation. + Copyright (C) 2015-2017 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 + <http://www.gnu.org/licenses/>. */ + +#ifndef _LIBC +# include <libc-config.h> +#endif + +#include <scratch_buffer.h> +#include <errno.h> +#include <string.h> + +bool +__libc_scratch_buffer_grow_preserve (struct scratch_buffer *buffer) +{ + size_t new_length = 2 * buffer->length; + void *new_ptr; + + if (buffer->data == buffer->__space) + { + /* Move buffer to the heap. No overflow is possible because + buffer->length describes a small buffer on the stack. */ + new_ptr = malloc (new_length); + if (new_ptr == NULL) + return false; + memcpy (new_ptr, buffer->__space, buffer->length); + } + else + { + /* Buffer was already on the heap. Check for overflow. */ + if (__glibc_likely (new_length >= buffer->length)) + new_ptr = realloc (buffer->data, new_length); + else + { + __set_errno (ENOMEM); + new_ptr = NULL; + } + + if (__glibc_unlikely (new_ptr == NULL)) + { + /* Deallocate, but buffer must remain valid to free. */ + free (buffer->data); + 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_grow_preserve)
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/lib/malloc/scratch_buffer_set_array_size.c Sat Sep 02 01:21:03 2017 -0700 @@ -0,0 +1,64 @@ +/* Variable-sized buffer with on-stack default allocation. + Copyright (C) 2015-2017 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 + <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)
--- a/lib/scratch_buffer.h Fri Sep 01 15:41:45 2017 -0700 +++ b/lib/scratch_buffer.h Sat Sep 02 01:21:03 2017 -0700 @@ -1,135 +1,4 @@ -/* Variable-sized buffer with on-stack default allocation. - Copyright (C) 2015-2017 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 - <http://www.gnu.org/licenses/>. */ - -#ifndef _SCRATCH_BUFFER_H -#define _SCRATCH_BUFFER_H - -/* Scratch buffers with a default stack allocation and fallback to - heap allocation. It is expected that this function is used in this - way: - - struct scratch_buffer tmpbuf; - scratch_buffer_init (&tmpbuf); - - while (!function_that_uses_buffer (tmpbuf.data, tmpbuf.length)) - if (!scratch_buffer_grow (&tmpbuf)) - return -1; - - scratch_buffer_free (&tmpbuf); - return 0; - - The allocation functions (scratch_buffer_grow, - scratch_buffer_grow_preserve, scratch_buffer_set_array_size) make - sure that the heap allocation, if any, is freed, so that the code - above does not have a memory leak. The buffer still remains in a - state that can be deallocated using scratch_buffer_free, so a loop - like this is valid as well: - - struct scratch_buffer tmpbuf; - scratch_buffer_init (&tmpbuf); - - while (!function_that_uses_buffer (tmpbuf.data, tmpbuf.length)) - if (!scratch_buffer_grow (&tmpbuf)) - break; - - scratch_buffer_free (&tmpbuf); - - scratch_buffer_grow and scratch_buffer_grow_preserve are guaranteed - to grow the buffer by at least 512 bytes. This means that when - using the scratch buffer as a backing store for a non-character - array whose element size, in bytes, is 512 or smaller, the scratch - buffer only has to grow once to make room for at least one more - element. -*/ - -#include <stdbool.h> -#include <stddef.h> -#include <stdlib.h> - -/* Scratch buffer. Must be initialized with scratch_buffer_init - before its use. */ -struct scratch_buffer { - void *data; /* Pointer to the beginning of the scratch area. */ - size_t length; /* Allocated space at the data pointer, in bytes. */ - max_align_t __space[(1023 + sizeof (max_align_t)) / sizeof (max_align_t)]; -}; - -/* Initializes *BUFFER so that BUFFER->data points to BUFFER->__space - and BUFFER->length reflects the available space. */ -static inline void -scratch_buffer_init (struct scratch_buffer *buffer) -{ - buffer->data = buffer->__space; - buffer->length = sizeof (buffer->__space); -} - -/* Deallocates *BUFFER (if it was heap-allocated). */ -static inline void -scratch_buffer_free (struct scratch_buffer *buffer) -{ - if (buffer->data != buffer->__space) - free (buffer->data); -} - -/* Grow *BUFFER by some arbitrary amount. The buffer contents is NOT - preserved. Return true on success, false on allocation failure (in - which case the old buffer is freed). On success, the new buffer is - larger than the previous size. On failure, *BUFFER is deallocated, - but remains in a free-able state, and errno is set. */ -bool __libc_scratch_buffer_grow (struct scratch_buffer *buffer); -libc_hidden_proto (__libc_scratch_buffer_grow) - -/* Alias for __libc_scratch_buffer_grow. */ -static __always_inline bool -scratch_buffer_grow (struct scratch_buffer *buffer) -{ - return __glibc_likely (__libc_scratch_buffer_grow (buffer)); -} - -/* Like __libc_scratch_buffer_grow, but preserve the old buffer - contents on success, as a prefix of the new buffer. */ -bool __libc_scratch_buffer_grow_preserve (struct scratch_buffer *buffer); -libc_hidden_proto (__libc_scratch_buffer_grow_preserve) - -/* Alias for __libc_scratch_buffer_grow_preserve. */ -static __always_inline bool -scratch_buffer_grow_preserve (struct scratch_buffer *buffer) -{ - return __glibc_likely (__libc_scratch_buffer_grow_preserve (buffer)); -} - -/* Grow *BUFFER so that it can store at least NELEM elements of SIZE - bytes. The buffer contents are NOT preserved. Both NELEM and SIZE - can be zero. Return true on success, false on allocation failure - (in which case the old buffer is freed, but *BUFFER remains in a - free-able state, and errno is set). It is unspecified whether this - function can reduce the array size. */ -bool __libc_scratch_buffer_set_array_size (struct scratch_buffer *buffer, - size_t nelem, size_t size); -libc_hidden_proto (__libc_scratch_buffer_set_array_size) - -/* Alias for __libc_scratch_set_array_size. */ -static __always_inline bool -scratch_buffer_set_array_size (struct scratch_buffer *buffer, - size_t nelem, size_t size) -{ - return __glibc_likely (__libc_scratch_buffer_set_array_size - (buffer, nelem, size)); -} - -#endif /* _SCRATCH_BUFFER_H */ +#define __libc_scratch_buffer_grow gl_scratch_buffer_grow +#define __libc_scratch_buffer_grow_preserve gl_scratch_buffer_grow_preserve +#define __libc_scratch_buffer_set_array_size gl_scratch_buffer_set_array_size +#include <malloc/scratch_buffer.h>
--- a/lib/scratch_buffer_grow.c Fri Sep 01 15:41:45 2017 -0700 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,56 +0,0 @@ -/* Variable-sized buffer with on-stack default allocation. - Copyright (C) 2015-2017 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 - <http://www.gnu.org/licenses/>. */ - -#ifndef _LIBC -# include <libc-config.h> -#endif - -#include <scratch_buffer.h> -#include <errno.h> - -bool -__libc_scratch_buffer_grow (struct scratch_buffer *buffer) -{ - void *new_ptr; - size_t new_length = buffer->length * 2; - - /* Discard old buffer. */ - scratch_buffer_free (buffer); - - /* Check for overflow. */ - if (__glibc_likely (new_length >= buffer->length)) - new_ptr = malloc (new_length); - else - { - __set_errno (ENOMEM); - new_ptr = NULL; - } - - if (__glibc_unlikely (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_grow)
--- a/lib/scratch_buffer_grow_preserve.c Fri Sep 01 15:41:45 2017 -0700 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,67 +0,0 @@ -/* Variable-sized buffer with on-stack default allocation. - Copyright (C) 2015-2017 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 - <http://www.gnu.org/licenses/>. */ - -#ifndef _LIBC -# include <libc-config.h> -#endif - -#include <scratch_buffer.h> -#include <errno.h> -#include <string.h> - -bool -__libc_scratch_buffer_grow_preserve (struct scratch_buffer *buffer) -{ - size_t new_length = 2 * buffer->length; - void *new_ptr; - - if (buffer->data == buffer->__space) - { - /* Move buffer to the heap. No overflow is possible because - buffer->length describes a small buffer on the stack. */ - new_ptr = malloc (new_length); - if (new_ptr == NULL) - return false; - memcpy (new_ptr, buffer->__space, buffer->length); - } - else - { - /* Buffer was already on the heap. Check for overflow. */ - if (__glibc_likely (new_length >= buffer->length)) - new_ptr = realloc (buffer->data, new_length); - else - { - __set_errno (ENOMEM); - new_ptr = NULL; - } - - if (__glibc_unlikely (new_ptr == NULL)) - { - /* Deallocate, but buffer must remain valid to free. */ - free (buffer->data); - 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_grow_preserve)
--- a/lib/scratch_buffer_set_array_size.c Fri Sep 01 15:41:45 2017 -0700 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,64 +0,0 @@ -/* Variable-sized buffer with on-stack default allocation. - Copyright (C) 2015-2017 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 - <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)
--- a/modules/scratch_buffer Fri Sep 01 15:41:45 2017 -0700 +++ b/modules/scratch_buffer Sat Sep 02 01:21:03 2017 -0700 @@ -3,9 +3,10 @@ Files: lib/scratch_buffer.h -lib/scratch_buffer_grow.c -lib/scratch_buffer_grow_preserve.c -lib/scratch_buffer_set_array_size.c +lib/malloc/scratch_buffer.h +lib/malloc/scratch_buffer_grow.c +lib/malloc/scratch_buffer_grow_preserve.c +lib/malloc/scratch_buffer_set_array_size.c Depends-on: libc-config @@ -13,14 +14,11 @@ stddef configure.ac: -AC_CHECK_FUNCS_ONCE([__libc_scratch_buffer_grow]) -if test "$ac_cv_func___libc_scratch_buffer_grow" != yes; then - AC_LIBOBJ([scratch_buffer_grow]) - AC_LIBOBJ([scratch_buffer_grow_preserve]) - AC_LIBOBJ([scratch_buffer_set_array_size]) -fi Makefile.am: +lib_SOURCES += malloc/scratch_buffer_grow.c \ + malloc/scratch_buffer_grow_preserve.c \ + malloc/scratch_buffer_set_array_size.c Include: <scratch_buffer.h>