/* 

 * tclLoadDld.c --

 *

 *	This procedure provides a version of the TclLoadFile that

 *	works with the "dld_link" and "dld_get_func" library procedures

 *	for dynamic loading.  It has been tested on Linux 1.1.95 and

 *	dld-3.2.7.  This file probably isn't needed anymore, since it

 *	makes more sense to use "dl_open" etc.

 *

 * Copyright (c) 1995-1997 Sun Microsystems, Inc.

 *

 * See the file "license.terms" for information on usage and redistribution

 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.

 *

 * RCS: @(#) $Id: tclLoadDld.c,v 1.12 2002/10/10 12:25:53 vincentdarley Exp $

 */

#include "tclInt.h"

#include "dld.h"

/*

 * In some systems, like SunOS 4.1.3, the RTLD_NOW flag isn't defined

 * and this argument to dlopen must always be 1.

 */

#ifndef RTLD_NOW

#   define RTLD_NOW 1

#endif

/*

 *----------------------------------------------------------------------

 *

 * TclpDlopen --

 *

 *	Dynamically loads a binary code file into memory and returns

 *	a handle to the new code.

 *

 * Results:

 *	A standard Tcl completion code.  If an error occurs, an error

 *	message is left in the interp's result.

 *

 * Side effects:

 *	New code suddenly appears in memory.

 *

 *----------------------------------------------------------------------

 */

int

TclpDlopen(interp, pathPtr, loadHandle, unloadProcPtr)

    Tcl_Interp *interp;		/* Used for error reporting. */

    Tcl_Obj *pathPtr;		/* Name of the file containing the desired

				 * code (UTF-8). */

    Tcl_LoadHandle *loadHandle;	/* Filled with token for dynamically loaded

				 * file which will be passed back to 

				 * (*unloadProcPtr)() to unload the file. */

    Tcl_FSUnloadFileProc **unloadProcPtr;	

				/* Filled with address of Tcl_FSUnloadFileProc

				 * function which should be used for

				 * this file. */

{

    static int firstTime = 1;

    int returnCode;

    char *fileName;

    CONST char *native;

    /*

     *  The dld package needs to know the pathname to the tcl binary.

     *  If that's not known, return an error.

     */

    if (firstTime) {

	if (tclExecutableName == NULL) {

	    Tcl_SetResult(interp,

		    "don't know name of application binary file, so can't initialize dynamic loader",

		    TCL_STATIC);

	    return TCL_ERROR;

	}

	returnCode = dld_init(tclExecutableName);

	if (returnCode != 0) {

	    Tcl_AppendResult(interp,

		    "initialization failed for dynamic loader: ",

		    dld_strerror(returnCode), (char *) NULL);

	    return TCL_ERROR;

	}

	firstTime = 0;

    }

    fileName = Tcl_GetString(pathPtr);

    /* 

     * First try the full path the user gave us.  This is particularly

     * important if the cwd is inside a vfs, and we are trying to load

     * using a relative path.

     */

    native = Tcl_FSGetNativePath(pathPtr);

    returnCode = dld_link(native);

    if (returnCode != 0) {

	Tcl_DString ds;

	native = Tcl_UtfToExternalDString(NULL, fileName, -1, &ds);

	returnCode = dld_link(native);

	Tcl_DStringFree(&ds);

    }

    if (returnCode != 0) {

	Tcl_AppendResult(interp, "couldn't load file \"", 

			 fileName, "\": ", 

			 dld_strerror(returnCode), (char *) NULL);

	return TCL_ERROR;

    }

    *loadHandle = (Tcl_LoadHandle) strcpy(

	    (char *) ckalloc((unsigned) (strlen(fileName) + 1)), fileName);

    *unloadProcPtr = &TclpUnloadFile;

    return TCL_OK;

}

/*

 *----------------------------------------------------------------------

 *

 * TclpFindSymbol --

 *

 *	Looks up a symbol, by name, through a handle associated with

 *	a previously loaded piece of code (shared library).

 *

 * Results:

 *	Returns a pointer to the function associated with 'symbol' if

 *	it is found.  Otherwise returns NULL and may leave an error

 *	message in the interp's result.

 *

 *----------------------------------------------------------------------

 */

Tcl_PackageInitProc*

TclpFindSymbol(interp, loadHandle, symbol) 

    Tcl_Interp *interp;

    Tcl_LoadHandle loadHandle;

    CONST char *symbol;

{

    return (Tcl_PackageInitProc *) dld_get_func(symbol);

}

/*

 *----------------------------------------------------------------------

 *

 * TclpUnloadFile --

 *

 *	Unloads a dynamically loaded binary code file from memory.

 *	Code pointers in the formerly loaded file are no longer valid

 *	after calling this function.

 *

 * Results:

 *	None.

 *

 * Side effects:

 *	Code removed from memory.

 *

 *----------------------------------------------------------------------

 */

void

TclpUnloadFile(loadHandle)

    Tcl_LoadHandle loadHandle;	/* loadHandle returned by a previous call

				 * to TclpDlopen().  The loadHandle is 

				 * a token that represents the loaded 

				 * file. */

{

    char *fileName;

    handle = (char *) loadHandle;

    dld_unlink_by_file(handle, 0);

    ckfree(handle);

}

/*

 *----------------------------------------------------------------------

 *

 * TclGuessPackageName --

 *

 *	If the "load" command is invoked without providing a package

 *	name, this procedure is invoked to try to figure it out.

 *

 * Results:

 *	Always returns 0 to indicate that we couldn't figure out a

 *	package name;  generic code will then try to guess the package

 *	from the file name.  A return value of 1 would have meant that

 *	we figured out the package name and put it in bufPtr.

 *

 * Side effects:

 *	None.

 *

 *----------------------------------------------------------------------

 */

int

TclGuessPackageName(fileName, bufPtr)

    CONST char *fileName;	/* Name of file containing package (already

				 * translated to local form if needed). */

    Tcl_DString *bufPtr;	/* Initialized empty dstring.  Append

				 * package name to this if possible. */

{

    return 0;

}