1 /* 2 3 Copyright 1995, 1998 The Open Group 4 5 Permission to use, copy, modify, distribute, and sell this software and its 6 documentation for any purpose is hereby granted without fee, provided that 7 the above copyright notice appear in all copies and that both that 8 copyright notice and this permission notice appear in supporting 9 documentation. 10 11 The above copyright notice and this permission notice shall be 12 included in all copies or substantial portions of the Software. 13 14 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 15 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 16 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 17 IN NO EVENT SHALL THE OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR 18 OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 19 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 20 OTHER DEALINGS IN THE SOFTWARE. 21 22 Except as contained in this notice, the name of The Open Group shall 23 not be used in advertising or otherwise to promote the sale, use or 24 other dealings in this Software without prior written authorization 25 from The Open Group. 26 27 */ 28 /* 29 * The purpose of this header is to define the macros ALLOCATE_LOCAL and 30 * DEALLOCATE_LOCAL appropriately for the platform being compiled on. 31 * These macros are used to make fast, function-local memory allocations. 32 * Their characteristics are as follows: 33 * 34 * void *ALLOCATE_LOCAL(int size) 35 * Returns a pointer to size bytes of memory, or NULL if the allocation 36 * failed. The memory must be freed with DEALLOCATE_LOCAL before the 37 * function that made the allocation returns. You should not ask for 38 * large blocks of memory with this function, since on many platforms 39 * the memory comes from the stack, which may have limited size. 40 * 41 * void DEALLOCATE_LOCAL(void *) 42 * Frees the memory allocated by ALLOCATE_LOCAL. Omission of this 43 * step may be harmless on some platforms, but will result in 44 * memory leaks or worse on others. 45 * 46 * Before including this file, you should define two macros, 47 * ALLOCATE_LOCAL_FALLBACK and DEALLOCATE_LOCAL_FALLBACK, that have the 48 * same characteristics as ALLOCATE_LOCAL and DEALLOCATE_LOCAL. The 49 * header uses the fallbacks if it doesn't know a "better" way to define 50 * ALLOCATE_LOCAL and DEALLOCATE_LOCAL. Typical usage would be: 51 * 52 * #define ALLOCATE_LOCAL_FALLBACK(_size) malloc(_size) 53 * #define DEALLOCATE_LOCAL_FALLBACK(_ptr) free(_ptr) 54 * #include "Xalloca.h" 55 */ 56 57 #ifndef XALLOCA_H 58 #define XALLOCA_H 1 59 60 #ifndef INCLUDE_ALLOCA_H 61 /* Need to add more here to match Imake *.cf's */ 62 # if defined(HAVE_ALLOCA_H) || defined(__SUNPRO_C) || defined(__SUNPRO_CC) 63 # define INCLUDE_ALLOCA_H 64 # endif 65 #endif 66 67 #ifdef INCLUDE_ALLOCA_H 68 # include <alloca.h> 69 #endif 70 71 #ifndef NO_ALLOCA 72 /* 73 * os-dependent definition of local allocation and deallocation 74 * If you want something other than (DE)ALLOCATE_LOCAL_FALLBACK 75 * for ALLOCATE/DEALLOCATE_LOCAL then you add that in here. 76 */ 77 78 79 # ifdef __GNUC__ 80 # ifndef alloca 81 # define alloca __builtin_alloca 82 # endif /* !alloca */ 83 # define ALLOCATE_LOCAL(size) alloca((int)(size)) 84 # else /* ! __GNUC__ */ 85 86 /* 87 * warning: old mips alloca (pre 2.10) is unusable, new one is built in 88 * Test is easy, the new one is named __builtin_alloca and comes 89 * from alloca.h which #defines alloca. 90 */ 91 # if defined(__sun) || defined(alloca) 92 /* 93 * Some System V boxes extract alloca.o from /lib/libPW.a; if you 94 * decide that you don't want to use alloca, you might want to fix it here. 95 */ 96 /* alloca might be a macro taking one arg (hi, Sun!), so give it one. */ 97 # if !defined(__cplusplus) 98 # define __Xnullarg /* as nothing */ 99 extern void *alloca(__Xnullarg); 100 # endif 101 # define ALLOCATE_LOCAL(size) alloca((int)(size)) 102 # endif /* who does alloca */ 103 # endif /* __GNUC__ */ 104 105 #endif /* NO_ALLOCA */ 106 107 #if !defined(ALLOCATE_LOCAL) 108 # if defined(ALLOCATE_LOCAL_FALLBACK) && defined(DEALLOCATE_LOCAL_FALLBACK) 109 # define ALLOCATE_LOCAL(_size) ALLOCATE_LOCAL_FALLBACK(_size) 110 # define DEALLOCATE_LOCAL(_ptr) DEALLOCATE_LOCAL_FALLBACK(_ptr) 111 # else /* no fallbacks supplied; error */ 112 # define ALLOCATE_LOCAL(_size) ALLOCATE_LOCAL_FALLBACK undefined! 113 # define DEALLOCATE_LOCAL(_ptr) DEALLOCATE_LOCAL_FALLBACK undefined! 114 # endif /* defined(ALLOCATE_LOCAL_FALLBACK && DEALLOCATE_LOCAL_FALLBACK) */ 115 #else 116 # if !defined(DEALLOCATE_LOCAL) 117 # define DEALLOCATE_LOCAL(_ptr) do {} while(0) 118 # endif 119 #endif /* defined(ALLOCATE_LOCAL) */ 120 121 #endif /* XALLOCA_H */ 122
