Tcl Source Code

static unsigned short emptyPage[256];

/*
 * Functions used only in this module.
 */

static int		BinaryProc(ClientData clientData,
			    const char *src, int srcLen, int flags,
			    Tcl_EncodingState *statePtr, char *dst, int dstLen,
			    int *srcReadPtr, int *dstWrotePtr,
			    int *dstCharsPtr);
static void		DupEncodingIntRep(Tcl_Obj *srcPtr, Tcl_Obj *dupPtr);
static void		EscapeFreeProc(ClientData clientData);
static int		EscapeFromUtfProc(ClientData clientData,
			    const char *src, int srcLen, int flags,
			    Tcl_EncodingState *statePtr, char *dst, int dstLen,
			    int *srcReadPtr, int *dstWrotePtr,
			    int *dstCharsPtr);

    /*
     * Create a few initial encodings. Note that the UTF-8 to UTF-8
     * translation is not a no-op, because it will turn a stream of improperly
     * formed UTF-8 into a properly formed stream.
     */

    type.encodingName	= "identity";
    type.toUtfProc	= BinaryProc;
    type.fromUtfProc	= BinaryProc;
    type.freeProc	= NULL;
    type.nullSize	= 1;
    type.clientData	= NULL;
    tclIdentityEncoding = Tcl_CreateEncoding(&type);

    type.encodingName	= "utf-8";
    type.toUtfProc	= UtfExtToUtfIntProc;
    type.fromUtfProc	= UtfIntToUtfExtProc;
    type.freeProc	= NULL;
    type.nullSize	= 1;
    type.clientData	= NULL;
    Tcl_CreateEncoding(&type);

    type.fromUtfProc    = EscapeFromUtfProc;
    type.freeProc	= EscapeFreeProc;
    type.nullSize	= 1;
    type.clientData	= dataPtr;

    return Tcl_CreateEncoding(&type);
}

/*
 *-------------------------------------------------------------------------
 *
 * BinaryProc --
 *
 *	The default conversion when no other conversion is specified. No
 *	translation is done; source bytes are copied directly to destination
 *	bytes.
 *
 * Results:
 *	Returns TCL_OK if conversion was successful.
 *
 * Side effects:
 *	None.
 *
 *-------------------------------------------------------------------------
 */

static int
BinaryProc(
    ClientData clientData,	/* Not used. */
    const char *src,		/* Source string (unknown encoding). */
    int srcLen,			/* Source string length in bytes. */
    int flags,			/* Conversion control flags. */
    Tcl_EncodingState *statePtr,/* Place for conversion routine to store state
				 * information used during a piecewise
				 * conversion. Contents of statePtr are
				 * initialized and/or reset by conversion
				 * routine under control of flags argument. */
    char *dst,			/* Output buffer in which converted string is
				 * stored. */
    int dstLen,			/* The maximum length of output buffer in
				 * bytes. */
    int *srcReadPtr,		/* Filled with the number of bytes from the
				 * source string that were converted. */
    int *dstWrotePtr,		/* Filled with the number of bytes that were
				 * stored in the output buffer as a result of
				 * the conversion. */
    int *dstCharsPtr)		/* Filled with the number of characters that
				 * correspond to the bytes stored in the
				 * output buffer. */
{
    int result;

    result = TCL_OK;
    dstLen -= TCL_UTF_MAX - 1;
    if (dstLen < 0) {
	dstLen = 0;
    }
    if ((flags & TCL_ENCODING_CHAR_LIMIT) && srcLen > *dstCharsPtr) {
	srcLen = *dstCharsPtr;
    }
    if (srcLen > dstLen) {
	srcLen = dstLen;
	result = TCL_CONVERT_NOSPACE;
    }

    *srcReadPtr = srcLen;
    *dstWrotePtr = srcLen;
    *dstCharsPtr = srcLen;
    memcpy(dst, src, (size_t) srcLen);
    return result;
}

/*
 *-------------------------------------------------------------------------
 *
 * UtfExtToUtfIntProc --
 *
 *	Convert from UTF-8 to UTF-8. While converting null-bytes from the