/* 
 * tclCompExpr.c --
 *
 *	This file contains the code to compile Tcl expressions.
 *
 * Copyright (c) 1997 Sun Microsystems, Inc.
 * Copyright (c) 1998-2000 by Scriptics Corporation.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: tclCompExpr.c,v 1.25 2004/10/08 15:39:52 dkf Exp $
 */

#include "tclInt.h"
#include "tclCompile.h"

/*
 * The stuff below is a bit of a hack so that this file can be used in

    ExprInfo *infoPtr;		/* Describes the compilation state for the
				 * expression being compiled. */
    CompileEnv *envPtr;		/* Holds resulting instructions. */
    Tcl_Token **endPtrPtr;	/* If successful, a pointer to the token
				 * just after the last token in the
				 * subexpression is stored here. */
{
    Tcl_Interp *interp = infoPtr->interp;
    Interp *iPtr = (Interp *) interp;
    MathFunc *mathFuncPtr;
    Tcl_HashEntry *hPtr;
    Tcl_Token *tokenPtr, *afterSubexprPtr;

    int code, i;

    /*
     * Look up the MathFunc record for the function.



     */

    code = TCL_OK;
    hPtr = Tcl_FindHashEntry(&iPtr->mathFuncTable, funcName);
    if (hPtr == NULL) {

	Tcl_AppendResult(interp, "unknown math function \"", funcName,
		"\"", (char *) NULL);
	code = TCL_ERROR;
	goto done;
    }
    mathFuncPtr = (MathFunc *) Tcl_GetHashValue(hPtr);

    /*
     * If not a builtin function, push an object with the function's name.
     */

    if (mathFuncPtr->builtinFuncIndex < 0) {
	TclEmitPush(TclRegisterNewLiteral(envPtr, funcName, -1), envPtr);
    }


    /*
     * Compile any arguments for the function.
     */


    tokenPtr = exprTokenPtr+2;
    afterSubexprPtr = exprTokenPtr + (exprTokenPtr->numComponents + 1);
    if (mathFuncPtr->numArgs > 0) {
	for (i = 0;  i < mathFuncPtr->numArgs;  i++) {
	    if (tokenPtr == afterSubexprPtr) {
		Tcl_SetObjResult(interp, Tcl_NewStringObj(
		        "too few arguments for math function", -1));
		code = TCL_ERROR;
		goto done;
	    }
	    code = CompileSubExpr(tokenPtr, infoPtr, envPtr);
	    if (code != TCL_OK) {
		goto done;

	    }
	    tokenPtr += (tokenPtr->numComponents + 1);
	}
	if (tokenPtr != afterSubexprPtr) {
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "too many arguments for math function", -1));
	    code = TCL_ERROR;
	    goto done;
	} 
    } else if (tokenPtr != afterSubexprPtr) {
	Tcl_SetObjResult(interp, Tcl_NewStringObj(
		"too many arguments for math function", -1));
	code = TCL_ERROR;
	goto done;
    }
    
    /*
     * Compile the call on the math function. Note that the "objc" argument
     * count for non-builtin functions is incremented by 1 to include the
     * function name itself.
     */

    if (mathFuncPtr->builtinFuncIndex >= 0) { /* a builtin function */
	/*
	 * Adjust the current stack depth by the number of arguments
	 * of the builtin function. This cannot be handled by the 
	 * TclEmitInstInt1 macro as the number of arguments is not
	 * passed as an operand.
	 */

	if (envPtr->maxStackDepth < envPtr->currStackDepth) {
	    envPtr->maxStackDepth = envPtr->currStackDepth;
	}
	TclEmitInstInt1(INST_CALL_BUILTIN_FUNC1,
	        mathFuncPtr->builtinFuncIndex, envPtr);
	envPtr->currStackDepth -= mathFuncPtr->numArgs;
    } else {
	TclEmitInstInt1(INST_CALL_FUNC1, (mathFuncPtr->numArgs+1), envPtr);
    }
    *endPtrPtr = afterSubexprPtr;

    done:

    return code;
}

/*
 *----------------------------------------------------------------------
 *
 * LogSyntaxError --
 *