diff options
Diffstat (limited to 'generic/tclInt.h')
| -rw-r--r-- | generic/tclInt.h | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/generic/tclInt.h b/generic/tclInt.h index ff89229..9729ec7 100644 --- a/generic/tclInt.h +++ b/generic/tclInt.h @@ -12,7 +12,7 @@ * See the file "license.terms" for information on usage and redistribution * of this file, and for a DISCLAIMER OF ALL WARRANTIES. * - * RCS: @(#) $Id: tclInt.h,v 1.155 2004/04/30 20:06:43 dgp Exp $ + * RCS: @(#) $Id: tclInt.h,v 1.156 2004/05/03 19:59:18 msofer Exp $ */ #ifndef _TCLINT @@ -1410,6 +1410,24 @@ typedef struct Interp { #define UCHAR(c) ((unsigned char) (c)) +/* + * This macro is used to determine the offset needed to safely allocate any + * data structure in memory. Given a starting offset or size, it "rounds up" + * or "aligns" the offset to the next 8-byte boundary so that any data + * structure can be placed at the resulting offset without fear of an + * alignment error. + * + * WARNING!! DO NOT USE THIS MACRO TO ALIGN POINTERS: it will produce + * the wrong result on platforms that allocate addresses that are divisible + * by 4 or 2. Only use it for offsets or sizes. + * + * This macro is only used by tclCompile.c in the core (Bug 926445). It + * however not be made file static, as extensions that touch bytecodes + * (notably tbcload) require it. + */ + +#define TCL_ALIGN(x) (((int)(x) + 7) & ~7) + /* * The following enum values are used to specify the runtime platform |