| #ifndef __ALT_ERRNO_H__ |
| #define __ALT_ERRNO_H__ |
| |
| /****************************************************************************** |
| * * |
| * License Agreement * |
| * * |
| * Copyright (c) 2004 Altera Corporation, San Jose, California, USA. * |
| * All rights reserved. * |
| * * |
| * Permission is hereby granted, free of charge, to any person obtaining a * |
| * copy of this software and associated documentation files (the "Software"), * |
| * to deal in the Software without restriction, including without limitation * |
| * the rights to use, copy, modify, merge, publish, distribute, sublicense, * |
| * and/or sell copies of the Software, and to permit persons to whom the * |
| * Software is furnished to do so, subject to the following conditions: * |
| * * |
| * The above copyright notice and this permission notice shall be included in * |
| * all copies or substantial portions of the Software. * |
| * * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * |
| * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER * |
| * DEALINGS IN THE SOFTWARE. * |
| * * |
| * * |
| * Altera does not recommend, suggest or require that this reference design * |
| * file be used in conjunction or combination with any other product. * |
| ******************************************************************************/ |
| |
| /****************************************************************************** |
| * * |
| * THIS IS A LIBRARY READ-ONLY SOURCE FILE. DO NOT EDIT. * |
| * * |
| ******************************************************************************/ |
| |
| /* |
| * errno is defined in <errno.h> so that it uses the thread local version |
| * stored in the location pointed to by "_impure_ptr". This means that the |
| * accesses to errno within the HAL library can cause the entirety of |
| * of the structure pointed to by "_impure_ptr" to be added to the |
| * users application. This can be undesirable in very small footprint systems. |
| * |
| * To avoid this happening, the HAL uses the macro ALT_ERRNO, defined below, |
| * to access errno, rather than accessing it directly. This macro will only |
| * use the thread local version if some other code has already caused it to be |
| * included into the system, otherwise it will use the global errno value. |
| * |
| * This causes a slight increases in code size where errno is accessed, but |
| * can lead to significant overall benefits in very small systems. The |
| * increase is inconsequential when compared to the size of the structure |
| * pointed to by _impure_ptr. |
| * |
| * Note that this macro accesses __errno() using an externally declared |
| * function pointer (alt_errno). This is done so that the function call uses the |
| * subroutine call instruction via a register rather than an immediate address. |
| * This is important in the case that the code has been linked for a high |
| * address, but __errno() is not being used. In this case the weak linkage |
| * would have resulted in the instruction: "call 0" which would fail to link. |
| */ |
| |
| extern int* (*alt_errno) (void); |
| |
| /* Must define this so that values such as EBADFD are defined in errno.h. */ |
| #define __LINUX_ERRNO_EXTENSIONS__ |
| |
| #include <errno.h> |
| |
| #include "alt_types.h" |
| |
| #undef errno |
| |
| extern int errno; |
| |
| static ALT_INLINE int* alt_get_errno(void) |
| { |
| return ((alt_errno) ? alt_errno() : &errno); |
| } |
| |
| #define ALT_ERRNO *alt_get_errno() |
| |
| #endif /* __ALT_ERRNO_H__ */ |