1 /* $Xorg: Xalloca.h,v 1.4 2001/02/09 02:03:22 xorgcvs Exp $ */ 2 3 /* 4 5 Copyright 1995, 1998 The Open Group 6 7 Permission to use, copy, modify, distribute, and sell this software and its 8 documentation for any purpose is hereby granted without fee, provided that 9 the above copyright notice appear in all copies and that both that 10 copyright notice and this permission notice appear in supporting 11 documentation. 12 13 The above copyright notice and this permission notice shall be 14 included in all copies or substantial portions of the Software. 15 16 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 17 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 18 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 19 IN NO EVENT SHALL THE OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR 20 OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 21 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 22 OTHER DEALINGS IN THE SOFTWARE. 23 24 Except as contained in this notice, the name of The Open Group shall 25 not be used in advertising or otherwise to promote the sale, use or 26 other dealings in this Software without prior written authorization 27 from The Open Group. 28 29 */ 30 /* $XFree86: xc/include/Xalloca.h,v 3.10 2001/12/14 19:53:25 dawes Exp $ */ 31 32 /* 33 * The purpose of this header is to define the macros ALLOCATE_LOCAL and 34 * DEALLOCATE_LOCAL appropriately for the platform being compiled on. 35 * These macros are used to make fast, function-local memory allocations. 36 * Their characteristics are as follows: 37 * 38 * void *ALLOCATE_LOCAL(int size) 39 * Returns a pointer to size bytes of memory, or NULL if the allocation 40 * failed. The memory must be freed with DEALLOCATE_LOCAL before the 41 * function that made the allocation returns. You should not ask for 42 * large blocks of memory with this function, since on many platforms 43 * the memory comes from the stack, which may have limited size. 44 * 45 * void DEALLOCATE_LOCAL(void *) 46 * Frees the memory allocated by ALLOCATE_LOCAL. Omission of this 47 * step may be harmless on some platforms, but will result in 48 * memory leaks or worse on others. 49 * 50 * Before including this file, you should define two macros, 51 * ALLOCATE_LOCAL_FALLBACK and DEALLOCATE_LOCAL_FALLBACK, that have the 52 * same characteristics as ALLOCATE_LOCAL and DEALLOCATE_LOCAL. The 53 * header uses the fallbacks if it doesn't know a "better" way to define 54 * ALLOCATE_LOCAL and DEALLOCATE_LOCAL. Typical usage would be: 55 * 56 * #define ALLOCATE_LOCAL_FALLBACK(_size) malloc(_size) 57 * #define DEALLOCATE_LOCAL_FALLBACK(_ptr) free(_ptr) 58 * #include "Xalloca.h" 59 */ 60 61 #ifndef XALLOCA_H 62 #define XALLOCA_H 1 63 64 #ifndef INCLUDE_ALLOCA_H 65 # if defined(__SUNPRO_C) /* Need to add more here to match Imake *.cf's */ 66 # define INCLUDE_ALLOCA_H 67 # endif 68 #endif 69 70 #ifdef INCLUDE_ALLOCA_H 71 # include <alloca.h> 72 #endif 73 74 #ifndef NO_ALLOCA 75 /* 76 * os-dependent definition of local allocation and deallocation 77 * If you want something other than (DE)ALLOCATE_LOCAL_FALLBACK 78 * for ALLOCATE/DEALLOCATE_LOCAL then you add that in here. 79 */ 80 # if defined(__HIGHC__) 81 # ifndef NCR 82 extern char *alloca(); 83 # if HCVERSION < 21003 84 # define ALLOCATE_LOCAL(size) alloca((int)(size)) 85 pragma on(alloca); 86 # else /* HCVERSION >= 21003 */ 87 # define ALLOCATE_LOCAL(size) _Alloca((int)(size)) 88 # endif /* HCVERSION < 21003 */ 89 # else /* NCR */ 90 # define ALLOCATE_LOCAL(size) alloca(size) 91 # endif 92 # endif /* defined(__HIGHC__) */ 93 94 95 # ifdef __GNUC__ 96 # ifndef alloca 97 # define alloca __builtin_alloca 98 # endif /* !alloca */ 99 # define ALLOCATE_LOCAL(size) alloca((int)(size)) 100 # else /* ! __GNUC__ */ 101 102 /* 103 * warning: old mips alloca (pre 2.10) is unusable, new one is built in 104 * Test is easy, the new one is named __builtin_alloca and comes 105 * from alloca.h which #defines alloca. 106 */ 107 # ifndef NCR 108 # if defined(vax) || defined(sun) || defined(apollo) || defined(stellar) || defined(alloca) 109 /* 110 * Some System V boxes extract alloca.o from /lib/libPW.a; if you 111 * decide that you don't want to use alloca, you might want to fix it here. 112 */ 113 /* alloca might be a macro taking one arg (hi, Sun!), so give it one. */ 114 # ifndef __sgi /* IRIX 5/6 has definition */ 115 # ifndef __QNX__ 116 # define __Xnullarg /* as nothing */ 117 # ifndef X_NOT_STDC_ENV 118 extern void *alloca(__Xnullarg); 119 # else 120 extern char *alloca(__Xnullarg); 121 # endif 122 # endif /* __QNX__ */ 123 # endif /* __sgi */ 124 # define ALLOCATE_LOCAL(size) alloca((int)(size)) 125 # endif /* who does alloca */ 126 # endif /* NCR */ 127 # endif /* __GNUC__ */ 128 129 #endif /* NO_ALLOCA */ 130 131 #if !defined(ALLOCATE_LOCAL) 132 # if defined(ALLOCATE_LOCAL_FALLBACK) && defined(DEALLOCATE_LOCAL_FALLBACK) 133 # define ALLOCATE_LOCAL(_size) ALLOCATE_LOCAL_FALLBACK(_size) 134 # define DEALLOCATE_LOCAL(_ptr) DEALLOCATE_LOCAL_FALLBACK(_ptr) 135 # else /* no fallbacks supplied; error */ 136 # define ALLOCATE_LOCAL(_size) ALLOCATE_LOCAL_FALLBACK undefined! 137 # define DEALLOCATE_LOCAL(_ptr) DEALLOCATE_LOCAL_FALLBACK undefined! 138 # endif /* defined(ALLOCATE_LOCAL_FALLBACK && DEALLOCATE_LOCAL_FALLBACK) */ 139 #else 140 # if !defined(DEALLOCATE_LOCAL) 141 # define DEALLOCATE_LOCAL(_ptr) do {} while(0) 142 # endif 143 #endif /* defined(ALLOCATE_LOCAL) */ 144 145 #endif /* XALLOCA_H */ 146
