From 29064d02c31b08ae41d41a93fd1439718373b196 Mon Sep 17 00:00:00 2001 From: Philipp Stephani Date: Thu, 24 Dec 2020 16:48:40 +0100 Subject: Update Gnulib. All changes in this commit are autogenerated by running admin/merge-gnulib. --- lib/malloc/scratch_buffer.h | 135 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 135 insertions(+) create mode 100644 lib/malloc/scratch_buffer.h (limited to 'lib/malloc/scratch_buffer.h') diff --git a/lib/malloc/scratch_buffer.h b/lib/malloc/scratch_buffer.h new file mode 100644 index 00000000000..b40478637c8 --- /dev/null +++ b/lib/malloc/scratch_buffer.h @@ -0,0 +1,135 @@ +/* Variable-sized buffer with on-stack default allocation. + Copyright (C) 2015-2020 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 General Public + License as published by the Free Software Foundation; either + version 3 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 + General Public License for more details. + + You should have received a copy of the GNU General Public + License along with the GNU C Library; if not, see + . */ + +#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 +#include +#include + +/* 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. */ + union { max_align_t __align; char __c[1024]; } __space; +}; + +/* 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.__c; + 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.__c) + 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 */ -- cgit v1.2.1 From ba05d005e5a81bc123ad8da928b1bccb6b160e7a Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Fri, 1 Jan 2021 01:13:56 -0800 Subject: Update copyright year to 2021 Run "TZ=UTC0 admin/update-copyright". --- lib/malloc/scratch_buffer.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib/malloc/scratch_buffer.h') diff --git a/lib/malloc/scratch_buffer.h b/lib/malloc/scratch_buffer.h index b40478637c8..6efca9ba3f4 100644 --- a/lib/malloc/scratch_buffer.h +++ b/lib/malloc/scratch_buffer.h @@ -1,5 +1,5 @@ /* Variable-sized buffer with on-stack default allocation. - Copyright (C) 2015-2020 Free Software Foundation, Inc. + Copyright (C) 2015-2021 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 -- cgit v1.2.1 From 1b59478f4cf442f5201500b0a9c66f4332fce640 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Fri, 1 Jan 2021 01:51:18 -0800 Subject: Update from Gnulib by running admin/merge-gnulib. --- lib/malloc/scratch_buffer.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'lib/malloc/scratch_buffer.h') diff --git a/lib/malloc/scratch_buffer.h b/lib/malloc/scratch_buffer.h index 6efca9ba3f4..26e306212d1 100644 --- a/lib/malloc/scratch_buffer.h +++ b/lib/malloc/scratch_buffer.h @@ -132,4 +132,20 @@ scratch_buffer_set_array_size (struct scratch_buffer *buffer, (buffer, nelem, size)); } +/* Return a copy of *BUFFER's first SIZE bytes as a heap-allocated block, + deallocating *BUFFER if it was heap-allocated. SIZE must be at + most *BUFFER's size. Return NULL (setting errno) on memory + exhaustion. */ +void *__libc_scratch_buffer_dupfree (struct scratch_buffer *buffer, + size_t size); +libc_hidden_proto (__libc_scratch_buffer_dupfree) + +/* Alias for __libc_scratch_dupfree. */ +static __always_inline void * +scratch_buffer_dupfree (struct scratch_buffer *buffer, size_t size) +{ + void *r = __libc_scratch_buffer_dupfree (buffer, size); + return __glibc_likely (r != NULL) ? r : NULL; +} + #endif /* _SCRATCH_BUFFER_H */ -- cgit v1.2.1 From 68a256c89270ef9e97bca6097967a9ed2b050f4a Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Mon, 4 Oct 2021 12:11:39 -0700 Subject: Update from Gnulib Make the following changes by hand, and run 'admin/merge-gnulib'. * .gitignore: Add lib/malloc/*.gl.h. * admin/merge-gnulib: Copy lib/af_alg.h and lib/save-cwd.h directly from Gnulib, without worrying about Gnulib modules, as these files are special cases. (AVOIDED_MODULES): Remove malloc-posix. * lib/malloc.c, lib/realloc.c, m4/malloc.m4, m4/realloc.m4: * m4/year2038.m4: New files, copied from Gnulib. * lib/malloca.c, lib/malloca.h: * m4/close-stream.m4, m4/glibc21.m4, m4/malloca.m4: Remove. These are either no longer present in Gnulib, or are no longer needed by modules that Emacs uses. * oldXMenu/AddPane.c, oldXmenu/Addsel.c: Include XmenuInt.h first; needed for new Gnulib. * src/xmenu.c: Call emacs_abort, not abort. --- lib/malloc/scratch_buffer.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'lib/malloc/scratch_buffer.h') diff --git a/lib/malloc/scratch_buffer.h b/lib/malloc/scratch_buffer.h index 26e306212d1..36d0bef4bb1 100644 --- a/lib/malloc/scratch_buffer.h +++ b/lib/malloc/scratch_buffer.h @@ -3,16 +3,16 @@ 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 General Public + modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either - version 3 of the License, or (at your option) any later version. + 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 - General Public License for more details. + Lesser General Public License for more details. - You should have received a copy of the GNU General Public + You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, see . */ -- cgit v1.2.1 From 19dcb237b5b02b36580294ab309124f346a66024 Mon Sep 17 00:00:00 2001 From: Eli Zaretskii Date: Sat, 1 Jan 2022 02:45:51 -0500 Subject: ; Add 2022 to copyright years. --- lib/malloc/scratch_buffer.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib/malloc/scratch_buffer.h') diff --git a/lib/malloc/scratch_buffer.h b/lib/malloc/scratch_buffer.h index 36d0bef4bb1..e4c5c8a85da 100644 --- a/lib/malloc/scratch_buffer.h +++ b/lib/malloc/scratch_buffer.h @@ -1,5 +1,5 @@ /* Variable-sized buffer with on-stack default allocation. - Copyright (C) 2015-2021 Free Software Foundation, Inc. + Copyright (C) 2015-2022 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 -- cgit v1.2.1