/*
 * 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 1.14.2.10 2005/10/18 20:46:18 dgp Exp $
 */

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

/*
 * Boolean variable that controls whether expression compilation tracing is

static Tcl_HashTable opHashTable;

/*
 * Declarations for local procedures to this file:
 */

static int		CompileCondExpr _ANSI_ARGS_((
			    Tcl_Token *exprTokenPtr, ExprInfo *infoPtr,
			    CompileEnv *envPtr, Tcl_Token **endPtrPtr));
static int		CompileLandOrLorExpr _ANSI_ARGS_((
			    Tcl_Token *exprTokenPtr, int opIndex,
			    ExprInfo *infoPtr, CompileEnv *envPtr,
			    Tcl_Token **endPtrPtr));
static int		CompileMathFuncCall _ANSI_ARGS_((
			    Tcl_Token *exprTokenPtr, CONST char *funcName,
			    ExprInfo *infoPtr, CompileEnv *envPtr,
			    Tcl_Token **endPtrPtr));
static int		CompileSubExpr _ANSI_ARGS_((
			    Tcl_Token *exprTokenPtr, ExprInfo *infoPtr,
			    CompileEnv *envPtr));
static void		LogSyntaxError _ANSI_ARGS_((ExprInfo *infoPtr));

/*
 * Macro used to debug the execution of the expression compiler.
 */

#ifdef TCL_COMPILE_DEBUG
#define TRACE(exprBytes, exprLength, tokenBytes, tokenLength) \

 * Side effects:
 *	Adds instructions to envPtr to evaluate the expression at runtime.
 *
 *----------------------------------------------------------------------
 */

int
TclCompileExpr(interp, script, numBytes, envPtr)
    Tcl_Interp *interp;		/* Used for error reporting. */
    CONST char *script;		/* The source script to compile. */
    int numBytes;		/* Number of bytes in script. If < 0, the
				 * string consists of all bytes up to the
				 * first null character. */
    CompileEnv *envPtr;		/* Holds resulting instructions. */
{
    ExprInfo info;
    Tcl_Parse parse;
    Tcl_HashEntry *hPtr;
    int new, i, code;

    /*

 *	Cleans up the compilation environment. At the moment, just the table
 *	of expression operators is freed.
 *
 *----------------------------------------------------------------------
 */

void
TclFinalizeCompilation()
{
    Tcl_MutexLock(&opMutex);
    if (opTableInitialized) {
	Tcl_DeleteHashTable(&opHashTable);
	opTableInitialized = 0;
    }
    Tcl_MutexUnlock(&opMutex);

 * Side effects:
 *	Adds instructions to envPtr to evaluate the subexpression.
 *
 *----------------------------------------------------------------------
 */

static int
CompileSubExpr(exprTokenPtr, infoPtr, envPtr)
    Tcl_Token *exprTokenPtr;	/* Points to TCL_TOKEN_SUB_EXPR token to
				 * compile. */
    ExprInfo *infoPtr;		/* Describes the compilation state for the
				 * expression being compiled. */
    CompileEnv *envPtr;		/* Holds resulting instructions. */
{
    Tcl_Interp *interp = infoPtr->interp;
    Tcl_Token *tokenPtr, *endPtr, *afterSubexprPtr;
    OperatorDesc *opDescPtr;
    Tcl_HashEntry *hPtr;
    CONST char *operator;
    Tcl_DString opBuf;

	    objIndex = TclRegisterNewLiteral(envPtr, "", 0);
	}
	TclEmitPush(objIndex, envPtr);
	tokenPtr += 1;
	break;
 
    case TCL_TOKEN_BS:
	length = Tcl_UtfBackslash(tokenPtr->start, (int *) NULL, buffer);
	if (length > 0) {
	    objIndex = TclRegisterNewLiteral(envPtr, buffer, length);
	} else {
	    objIndex = TclRegisterNewLiteral(envPtr, "", 0);
	}
	TclEmitPush(objIndex, envPtr);
	tokenPtr += 1;

 * Side effects:
 *	Adds instructions to envPtr to evaluate the expression at runtime.
 *
 *----------------------------------------------------------------------
 */

static int
CompileLandOrLorExpr(exprTokenPtr, opIndex, infoPtr, envPtr, endPtrPtr)
    Tcl_Token *exprTokenPtr;	/* Points to TCL_TOKEN_SUB_EXPR token
				 * containing the "&&" or "||" operator. */
    int opIndex;		/* A code describing the expression operator:
				 * either OP_LAND or OP_LOR. */
    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. */
{
    JumpFixup shortCircuitFixup;/* Used to fix up the short circuit jump after
				 * the first subexpression. */
    JumpFixup shortCircuitFixup2;
				/* Used to fix up the second jump to the

 * Side effects:
 *	Adds instructions to envPtr to evaluate the expression at runtime.
 *
 *----------------------------------------------------------------------
 */

static int
CompileCondExpr(exprTokenPtr, infoPtr, envPtr, endPtrPtr)
    Tcl_Token *exprTokenPtr;	/* Points to TCL_TOKEN_SUB_EXPR token
				 * containing the "?" operator. */
    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. */
{
    JumpFixup jumpAroundThenFixup, jumpAroundElseFixup;
				/* Used to update or replace one-byte jumps
				 * around the then and else expressions when
				 * their target PCs are determined. */

 *	Adds instructions to envPtr to evaluate the math function at
 *	runtime.
 *
 *----------------------------------------------------------------------
 */

static int
CompileMathFuncCall(exprTokenPtr, funcName, infoPtr, envPtr, endPtrPtr)
    Tcl_Token *exprTokenPtr;	/* Points to TCL_TOKEN_SUB_EXPR token
				 * containing the math function call. */
    CONST char *funcName;	/* Name of the math function. */
    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_DString cmdName;
    int objIndex;
    Tcl_Token *tokenPtr, *afterSubexprPtr;
    int argCount;

 *	Sets the interpreter result to an error message describing the
 *	expression that was being compiled when the error occurred.
 *
 *----------------------------------------------------------------------
 */

static void
LogSyntaxError(infoPtr)
    ExprInfo *infoPtr;		/* Describes the compilation state for the
				 * expression being compiled. */
{
    Tcl_Obj *result =
	    Tcl_NewStringObj("syntax error in expression \"", -1);

    TclAppendLimitedToObj(result, infoPtr->expr,
	    (int)(infoPtr->lastChar - infoPtr->expr), 60, "");
    Tcl_AppendToObj(result, "\"", -1);
    Tcl_SetObjResult(infoPtr->interp, result);
}

/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * End:
 */