diff options
Diffstat (limited to 'generic/tclCmdIL.c')
| -rw-r--r-- | generic/tclCmdIL.c | 53 |
1 files changed, 40 insertions, 13 deletions
diff --git a/generic/tclCmdIL.c b/generic/tclCmdIL.c index c7b5e19..ec8dd4c 100644 --- a/generic/tclCmdIL.c +++ b/generic/tclCmdIL.c @@ -15,7 +15,7 @@ * See the file "license.terms" for information on usage and redistribution * of this file, and for a DISCLAIMER OF ALL WARRANTIES. * - * RCS: @(#) $Id: tclCmdIL.c,v 1.55 2003/10/15 13:15:45 dkf Exp $ + * RCS: @(#) $Id: tclCmdIL.c,v 1.56 2003/11/01 01:20:33 dkf Exp $ */ #include "tclInt.h" @@ -2650,7 +2650,7 @@ Tcl_LrepeatObjCmd(dummy, interp, objc, objv) register int objc; /* Number of arguments. */ register Tcl_Obj *CONST objv[]; /* The argument objects. */ { - int elementCount, i, j, k, result; + int elementCount, i, result; Tcl_Obj **dataArray; /* @@ -2685,22 +2685,50 @@ Tcl_LrepeatObjCmd(dummy, interp, objc, objv) * elementCount times. Note that we don't bother with stack * allocation for this, as we expect this function to be used * mainly when stack allocation would be inappropriate anyway. + * First check to see if we'd overflow and try to allocate an + * object larger than our memory allocator allows. Note that this + * is actually a fairly small value when you're on a serious + * 64-bit machine, but that requires API changes to fix. * - * POSSIBLE FUTURE ENHANCEMENT: Build the resulting list object - * directly and avoid a copy. + * We allocate using attemptckalloc() because if we ask for + * something big but can't get it, we've still got a high chance + * of having a proper failover strategy. If *that* fails to get + * memory, panic() will happen just a few lines lower... */ - dataArray = (Tcl_Obj **) ckalloc(elementCount * objc * sizeof(Tcl_Obj)); + if (elementCount > INT_MAX/sizeof(Tcl_Obj *)/objc) { + Tcl_AppendResult(interp, "overflow of maximum list length", NULL); + return TCL_ERROR; + } + + dataArray = (Tcl_Obj **) + attemptckalloc(elementCount * objc * sizeof(Tcl_Obj *)); + + if (dataArray == NULL) { + Tcl_AppendResult(interp, "insufficient memory to create list", NULL); + return TCL_ERROR; + } /* - * Set the elements. Note that this ends up setting k to the - * total number of elements. + * Set the elements. Note that we handle the common degenerate + * case of a single value being repeated separately to permit the + * compiler as much room as possible to optimize a loop that might + * be run a very large number of times. */ - k = 0; - for (i=0 ; i<elementCount ; i++) { - for (j=0 ; j<objc ; j++) { - dataArray[k++] = objv[j]; + if (objc == 1) { + register Tcl_Obj *tmpPtr = objv[0]; + + for (i=0 ; i<elementCount ; i++) { + dataArray[i] = tmpPtr; + } + } else { + int j, k = 0; + + for (i=0 ; i<elementCount ; i++) { + for (j=0 ; j<objc ; j++) { + dataArray[k++] = objv[j]; + } } } @@ -2708,8 +2736,7 @@ Tcl_LrepeatObjCmd(dummy, interp, objc, objv) * Build the result list, clean up and return. */ - Tcl_SetObjResult(interp, Tcl_NewListObj(k, dataArray)); - ckfree((char*) dataArray); + Tcl_SetObjResult(interp, TclNewListObjDirect(elementCount*objc,dataArray)); return TCL_OK; } |