diff options
Diffstat (limited to 'generic/tclBasic.c')
| -rw-r--r-- | generic/tclBasic.c | 53 |
1 files changed, 52 insertions, 1 deletions
diff --git a/generic/tclBasic.c b/generic/tclBasic.c index 0376a0a..fa9eb6e 100644 --- a/generic/tclBasic.c +++ b/generic/tclBasic.c @@ -16,7 +16,7 @@ * See the file "license.terms" for information on usage and redistribution of * this file, and for a DISCLAIMER OF ALL WARRANTIES. * - * RCS: @(#) $Id: tclBasic.c,v 1.412 2009/12/06 18:12:26 msofer Exp $ + * RCS: @(#) $Id: tclBasic.c,v 1.413 2009/12/06 20:35:38 msofer Exp $ */ #include "tclInt.h" @@ -8180,6 +8180,57 @@ Tcl_NRCmdSwap( * FIXME NRE! */ +void +TclSpliceTailcall ( + Tcl_Interp *interp, + TEOV_callback *tailcallPtr) +{ + /* + * Find the splicing spot: right before the NRCommand of the thing + * being tailcalled. Note that we skip NRCommands marked in data[1] + * (used by command redirectors) + */ + + Interp *iPtr = (Interp *) interp; + TEOV_callback *runPtr; + ExecEnv *eePtr = NULL; + + + + restart: + for (runPtr = TOP_CB(interp); runPtr; runPtr = runPtr->nextPtr) { + if (((runPtr->procPtr) == NRCommand) && !runPtr->data[1]) { + break; + } + } + if (!runPtr) { + /* + * If we are tailcalling out of a coroutine, the splicing spot is + * in the caller's execEnv: go find it! + */ + + CoroutineData *corPtr = iPtr->execEnvPtr->corPtr; + if (corPtr) { + eePtr = iPtr->execEnvPtr; + iPtr->execEnvPtr = corPtr->callerEEPtr; + goto restart; + } + Tcl_Panic("Tailcall cannot find the right splicing spot: should not happen!"); + } + + tailcallPtr->nextPtr = runPtr->nextPtr; + runPtr->nextPtr = tailcallPtr; + + if (eePtr) { + /* + * Restore the right execEnv if it was swapped for tailcalling out + * of a coroutine. + */ + + iPtr->execEnvPtr = eePtr; + } +} + int TclNRTailcallObjCmd( ClientData clientData, |