/* 

  * 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;

 }