Mercurial > gnulib
view lib/i-ring.h @ 40212:8da9577294da
unistr/*, uniconv/*: Fix undefined behaviour.
Reported by Jeffrey Walton <noloader@gmail.com>.
* lib/unistr/u-cpy.h (FUNC): Don't invoke memcpy with a zero size.
* lib/unistr/u-cpy-alloc.h (FUNC): Likewise.
* lib/uniconv/u8-conv-from-enc.c (u8_conv_from_encoding): Likewise.
* lib/uniconv/u8-conv-to-enc.c (u8_conv_to_encoding): Likewise.
author | Bruno Haible <bruno@clisp.org> |
---|---|
date | Sat, 09 Mar 2019 00:01:47 +0100 |
parents | b06060465f09 |
children |
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/* definitions for a simple ring buffer Copyright (C) 2006, 2009-2019 Free Software Foundation, Inc. This program 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. This program 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 this program. If not, see <https://www.gnu.org/licenses/>. */ #include <stdbool.h> #include "verify.h" enum { I_RING_SIZE = 4 }; verify (1 <= I_RING_SIZE); /* When ir_empty is true, the ring is empty. Otherwise, ir_data[B..F] are defined, where B..F is the contiguous range of indices, modulo I_RING_SIZE, from back to front, inclusive. Undefined elements of ir_data are always set to ir_default_val. Popping from an empty ring aborts. Pushing onto a full ring returns the displaced value. An empty ring has F==B and ir_empty == true. A ring with one entry still has F==B, but now ir_empty == false. */ struct I_ring { int ir_data[I_RING_SIZE]; int ir_default_val; unsigned int ir_front; unsigned int ir_back; bool ir_empty; }; typedef struct I_ring I_ring; void i_ring_init (I_ring *ir, int ir_default_val); int i_ring_push (I_ring *ir, int val); int i_ring_pop (I_ring *ir); bool i_ring_empty (I_ring const *ir) _GL_ATTRIBUTE_PURE;