/* 
 * tclLoadNext.c --
 *
 *	This procedure provides a version of the TclLoadFile that
 *	works with NeXTs rld_* dynamic loading.  This file provided
 *	by Pedja Bogdanovich.
 *
 * 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: tclLoadNext.c,v 1.7 2002/01/09 19:09:28 kennykb Exp $
 */

#include "tclInt.h"
#include <mach-o/rld.h>
#include <streams/streams.h>

/*
 *----------------------------------------------------------------------
 *
 * TclpLoadFile --
 *
 *	Dynamically loads a binary code file into memory and returns
 *	the addresses of two procedures within that file, if they
 *	are defined.
 *
 * Results:
 *	A standard Tcl completion code.  If an error occurs, an error
 *	message is left in the interp's result.  *proc1Ptr and *proc2Ptr
 *	are filled in with the addresses of the symbols given by
 *	*sym1 and *sym2, or NULL if those symbols can't be found.
 *
 * Side effects:
 *	New code suddenly appears in memory.
 *
 *----------------------------------------------------------------------
 */

int
TclpLoadFile(interp, pathPtr, sym1, sym2, proc1Ptr, proc2Ptr, 
	     clientDataPtr, unloadProcPtr)
    Tcl_Interp *interp;		/* Used for error reporting. */
    Tcl_Obj *pathPtr;		/* Name of the file containing the desired
				 * code. */
    CONST char *sym1, *sym2;	/* Names of two procedures to look up in
				 * the file's symbol table. */
    Tcl_PackageInitProc **proc1Ptr, **proc2Ptr;
				/* Where to return the addresses corresponding
				 * to sym1 and sym2. */
    ClientData *clientDataPtr;	/* 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. */
{
  struct mach_header *header;
  char *data;
  int len, maxlen;
  char *files[]={fileName,NULL};
  NXStream *errorStream=NXOpenMemory(0,0,NX_READWRITE);
  char *fileName = Tcl_GetString(pathPtr);
  
  if(!rld_load(errorStream,&header,files,NULL)) {
    NXGetMemoryBuffer(errorStream,&data,&len,&maxlen);
    Tcl_AppendResult(interp,"couldn't load file \"",fileName,"\": ",data,NULL);
    NXCloseMemory(errorStream,NX_FREEBUFFER);
    return TCL_ERROR;
  }
  NXCloseMemory(errorStream,NX_FREEBUFFER);

  *proc1Ptr=NULL;
  if(sym1) {
    char sym[strlen(sym1)+2];
    sym[0]='_'; sym[1]=0; strcat(sym,sym1);
    rld_lookup(NULL,sym,(unsigned long *)proc1Ptr);
  }

  *proc2Ptr=NULL;
  if(sym2) {
    char sym[strlen(sym2)+2];
    sym[0]='_'; sym[1]=0; strcat(sym,sym2);
    rld_lookup(NULL,sym,(unsigned long *)proc2Ptr);
  }
  *clientDataPtr = NULL;
  *unloadProcPtr = &TclpUnloadFile;
  
  return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * 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:
 *	Does nothing.  Can anything be done?
 *
 *----------------------------------------------------------------------
 */

void
TclpUnloadFile(clientData)
    ClientData clientData;	/* ClientData returned by a previous call
				 * to TclpLoadFile().  The clientData is 
				 * a token that represents the loaded 
				 * file. */
{
}

/*
 *----------------------------------------------------------------------
 *
 * 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;
}