1 /* $XConsortium: Xalloca.h /main/6 1996/09/28 16:17:22 rws $ */ 2 3 /* 4 5 Copyright (c) 1995 X Consortium 6 7 Permission is hereby granted, free of charge, to any person obtaining 8 a copy of this software and associated documentation files (the 9 "Software"), to deal in the Software without restriction, including 10 without limitation the rights to use, copy, modify, merge, publish, 11 distribute, sublicense, and/or sell copies of the Software, and to 12 permit persons to whom the Software is furnished to do so, subject to 13 the following conditions: 14 15 The above copyright notice and this permission notice shall be 16 included in all copies or substantial portions of the Software. 17 18 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 19 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 20 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 21 IN NO EVENT SHALL THE X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR 22 OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 23 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 24 OTHER DEALINGS IN THE SOFTWARE. 25 26 Except as contained in this notice, the name of the X Consortium shall 27 not be used in advertising or otherwise to promote the sale, use or 28 other dealings in this Software without prior written authorization 29 from the X Consortium. 30 31 */ 32 33 /* 34 * The purpose of this header is to define the macros ALLOCATE_LOCAL and 35 * DEALLOCATE_LOCAL appropriately for the platform being compiled on. 36 * These macros are used to make fast, function-local memory allocations. 37 * Their characteristics are as follows: 38 * 39 * void *ALLOCATE_LOCAL(int size) 40 * Returns a pointer to size bytes of memory, or NULL if the allocation 41 * failed. The memory must be freed with DEALLOCATE_LOCAL before the 42 * function that made the allocation returns. You should not ask for 43 * large blocks of memory with this function, since on many platforms 44 * the memory comes from the stack, which may have limited size. 45 * 46 * void DEALLOCATE_LOCAL(void *) 47 * Frees the memory allocated by ALLOCATE_LOCAL. Omission of this 48 * step may be harmless on some platforms, but will result in 49 * memory leaks or worse on others. 50 * 51 * Before including this file, you should define two macros, 52 * ALLOCATE_LOCAL_FALLBACK and DEALLOCATE_LOCAL_FALLBACK, that have the 53 * same characteristics as ALLOCATE_LOCAL and DEALLOCATE_LOCAL. The 54 * header uses the fallbacks if it doesn't know a "better" way to define 55 * ALLOCATE_LOCAL and DEALLOCATE_LOCAL. Typical usage would be: 56 * 57 * #define ALLOCATE_LOCAL_FALLBACK(_size) malloc(_size) 58 * #define DEALLOCATE_LOCAL_FALLBACK(_ptr) free(_ptr) 59 * #include "Xalloca.h" 60 */ 61 62 #ifndef XALLOCA_H 63 #define XALLOCA_H 1 64 65 #ifdef INCLUDE_ALLOCA_H 66 # include <alloca.h> 67 #endif 68 69 #ifndef NO_ALLOCA 70 /* 71 * os-dependent definition of local allocation and deallocation 72 * If you want something other than (DE)ALLOCATE_LOCAL_FALLBACK 73 * for ALLOCATE/DEALLOCATE_LOCAL then you add that in here. 74 */ 75 # if defined(__HIGHC__) 76 # ifndef NCR 77 extern char *alloca(); 78 # if HCVERSION < 21003 79 # define ALLOCATE_LOCAL(size) alloca((int)(size)) 80 pragma on(alloca); 81 # else /* HCVERSION >= 21003 */ 82 # define ALLOCATE_LOCAL(size) _Alloca((int)(size)) 83 # endif /* HCVERSION < 21003 */ 84 # else /* NCR */ 85 # define ALLOCATE_LOCAL(size) alloca(size) 86 # endif 87 # define DEALLOCATE_LOCAL(ptr) /* as nothing */ 88 # endif /* defined(__HIGHC__) */ 89 90 91 # ifdef __GNUC__ 92 # ifndef alloca 93 # define alloca __builtin_alloca 94 # endif /* !alloca */ 95 # define ALLOCATE_LOCAL(size) alloca((int)(size)) 96 # define DEALLOCATE_LOCAL(ptr) /* as nothing */ 97 # else /* ! __GNUC__ */ 98 99 /* 100 * warning: old mips alloca (pre 2.10) is unusable, new one is built in 101 * Test is easy, the new one is named __builtin_alloca and comes 102 * from alloca.h which #defines alloca. 103 */ 104 # ifndef NCR 105 # if defined(vax) || defined(sun) || defined(apollo) || defined(stellar) || defined(USL) || defined(alloca) 106 /* 107 * Some System V boxes extract alloca.o from /lib/libPW.a; if you 108 * decide that you don't want to use alloca, you might want to fix it here. 109 */ 110 /* alloca might be a macro taking one arg (hi, Sun!), so give it one. */ 111 # ifndef __sgi /* IRIX 5/6 has definition */ 112 # define __Xnullarg /* as nothing */ 113 # ifndef X_NOT_STDC_ENV 114 extern void *alloca(__Xnullarg); 115 # else 116 extern char *alloca(__Xnullarg); 117 # endif 118 # endif /* __sgi */ 119 # define ALLOCATE_LOCAL(size) alloca((int)(size)) 120 # define DEALLOCATE_LOCAL(ptr) /* as nothing */ 121 # endif /* who does alloca */ 122 # endif /* NCR */ 123 # endif /* __GNUC__ */ 124 125 #endif /* NO_ALLOCA */ 126 127 #if !defined(ALLOCATE_LOCAL) 128 # if defined(ALLOCATE_LOCAL_FALLBACK) && defined(DEALLOCATE_LOCAL_FALLBACK) 129 # define ALLOCATE_LOCAL(_size) ALLOCATE_LOCAL_FALLBACK(_size) 130 # define DEALLOCATE_LOCAL(_ptr) DEALLOCATE_LOCAL_FALLBACK(_ptr) 131 # else /* no fallbacks supplied; error */ 132 # define ALLOCATE_LOCAL(_size) ALLOCATE_LOCAL_FALLBACK undefined! 133 # define DEALLOCATE_LOCAL(_ptr) DEALLOCATE_LOCAL_FALLBACK undefined! 134 # endif /* defined(ALLOCATE_LOCAL_FALLBACK && DEALLOCATE_LOCAL_FALLBACK) */ 135 #endif /* !defined(ALLOCATE_LOCAL) */ 136 137 #endif /* XALLOCA_H */ 138