Tcl Source Code

    ForeachInfo *infoPtr = NULL;/* Points to the structure describing this
				 * foreach command. Stored in a AuxData
				 * record in the ByteCode. */
    Tcl_Token *tokenPtr, *bodyTokenPtr;
    unsigned char *jumpPc;
    JumpFixup jumpFalseFixup;
    int jumpBackDist, jumpBackOffset, infoIndex, range;
    int numWords, numLists, numVars, loopIndex, tempVar, i, j, code = TCL_OK;
    int savedStackDepth = envPtr->currStackDepth;
    Tcl_Obj *varListObj = NULL;
    DefineLineInformation;	/* TIP #280 */

    /*
     * If the foreach command isn't in a procedure, don't compile it inline:
     * the payoff is too small.

    /*
     * Parse each var list into sequence of var names. Don't
     * compile the foreach inline if any var name needs substitutions or isn't
     * a scalar, or if any var list needs substitutions.
     */

    loopIndex = 0;
    varListObj = Tcl_NewObj();
    for (i = 0, tokenPtr = parsePtr->tokenPtr;
	    i < numWords-1;
	    i++, tokenPtr = TokenAfter(tokenPtr)) {
	ForeachVarList *varListPtr;

	if (i%2 != 1) {

	    code = TCL_ERROR;
	    goto done;
	}

	varListPtr = (ForeachVarList *) ckalloc((unsigned)
		sizeof(ForeachVarList) + numVars*sizeof(int));
	varListPtr->numVars = numVars;
	infoPtr->varLists[loopIndex] = varListPtr;
	infoPtr->numLists++;

	for (j = 0;  j < numVars;  j++) {
	    Tcl_Obj *varNameObj;
	    Tcl_Token token[2];
	    int varIndex, isSimple, isScalar;

		code = TCL_ERROR;
		goto done;
	    }
	    varListPtr->varIndexes[j] = varIndex;
	}

	Tcl_SetObjLength(varListObj, 0);
	loopIndex++;
    }

    /*
     * We will compile the foreach command. Reserve (numLists + 1) temporary
     * variables:
     *    - numLists temps to hold each value list
     *    - 1 temp for the loop counter (index of next element in each list)
     *
     * At this time we don't try to reuse temporaries; if there are two
     * nonoverlapping foreach loops, they don't share any temps.
     */

    tempVar = TclFindCompiledLocal(NULL, 0, 1, procPtr);
    infoPtr->firstValueTemp = tempVar;
    for (loopIndex = 1;  loopIndex < numLists;  loopIndex++) {
	TclFindCompiledLocal(NULL, 0, 1, procPtr);
    }
    infoPtr->loopCtTemp = TclFindCompiledLocal(NULL, 0, 1, procPtr);

    infoIndex = TclCreateAuxData(infoPtr, &tclForeachInfoType, envPtr);

    /*
     * Create an exception record to handle [break] and [continue].
     */

    range = DeclareExceptionRange(envPtr, LOOP_EXCEPTION_RANGE);

    /*
     * Evaluate then store each value list in the associated temporary.
     */

    loopIndex = 0;
    for (i = 0, tokenPtr = parsePtr->tokenPtr;
	    i < numWords-1;
	    i++, tokenPtr = TokenAfter(tokenPtr)) {
	if ((i%2 == 0) && (i > 0)) {
	    SetLineInformation (i);
	    CompileTokens(envPtr, tokenPtr, interp);
	    if (tempVar <= 255) {
		TclEmitInstInt1(INST_STORE_SCALAR1, tempVar, envPtr);
	    } else {
		TclEmitInstInt4(INST_STORE_SCALAR4, tempVar, envPtr);
	    }
	    TclEmitOpcode(INST_POP, envPtr);
	    loopIndex++; tempVar++;
	}
    }

    /*
     * Initialize the temporary var that holds the count of loop iterations.
     */