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Sourcecode: tcl8.3 version File versions  Download package

tclWinLoad.c

/* 
 * tclWinLoad.c --
 *
 *    This procedure provides a version of the TclLoadFile that
 *    works with the Windows "LoadLibrary" and "GetProcAddress"
 *    API for dynamic loading.
 *
 * 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: tclWinLoad.c,v 1.5.2.1 2001/04/03 22:54:39 hobbs Exp $
 */

#include "tclWinInt.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.
 *
 * Side effects:
 *    New code suddenly appears in memory.
 *
 *----------------------------------------------------------------------
 */

int
TclpLoadFile(interp, fileName, sym1, sym2, proc1Ptr, proc2Ptr, clientDataPtr)
    Tcl_Interp *interp;       /* Used for error reporting. */
    char *fileName;           /* Name of the file containing the desired
                         * code. */
    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 
                         * TclpUnloadFile() to unload the file. */
{
    HINSTANCE handle;
    TCHAR *nativeName;
    Tcl_DString ds;

    nativeName = Tcl_WinUtfToTChar(fileName, -1, &ds);
    handle = (*tclWinProcs->loadLibraryProc)(nativeName);
    Tcl_DStringFree(&ds);

    *clientDataPtr = (ClientData) handle;
    
    if (handle == NULL) {
      DWORD lastError = GetLastError();
#if 0
      /*
       * It would be ideal if the FormatMessage stuff worked better,
       * but unfortunately it doesn't seem to want to...
       */
      LPTSTR lpMsgBuf;
      char *buf;
      int size;
      size = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM |
            FORMAT_MESSAGE_ALLOCATE_BUFFER, NULL, lastError, 0,
            (LPTSTR) &lpMsgBuf, 0, NULL);
      buf = (char *) ckalloc((unsigned) TCL_INTEGER_SPACE + size + 1);
      sprintf(buf, "%d %s", lastError, (char *)lpMsgBuf);
#endif
      Tcl_AppendResult(interp, "couldn't load library \"",
            fileName, "\": ", (char *) NULL);
      /*
       * Check for possible DLL errors.  This doesn't work quite right,
       * because Windows seems to only return ERROR_MOD_NOT_FOUND for
       * just about any problem, but it's better than nothing.  It'd be
       * even better if there was a way to get what DLLs
       */
      switch (lastError) {
          case ERROR_MOD_NOT_FOUND:
          case ERROR_DLL_NOT_FOUND:
            Tcl_AppendResult(interp, "this library or a dependent library",
                  " could not be found in library path",
                  (char *) NULL);
            break;
          case ERROR_PROC_NOT_FOUND:
            Tcl_AppendResult(interp, "could not find specified procedure",
                  (char *) NULL);
            break;
          case ERROR_INVALID_DLL:
            Tcl_AppendResult(interp, "this library or a dependent library",
                  " is damaged", (char *) NULL);
            break;
          case ERROR_DLL_INIT_FAILED:
            Tcl_AppendResult(interp, "the library initialization",
                  " routine failed", (char *) NULL);
            break;
          default:
            TclWinConvertError(lastError);
            Tcl_AppendResult(interp, Tcl_PosixError(interp),
                  (char *) NULL);
      }
      return TCL_ERROR;
    }

    /*
     * For each symbol, check for both Symbol and _Symbol, since Borland
     * generates C symbols with a leading '_' by default.
     */

    *proc1Ptr = (Tcl_PackageInitProc *) GetProcAddress(handle, sym1);
    if (*proc1Ptr == NULL) {
      Tcl_DStringAppend(&ds, "_", 1);
      sym1 = Tcl_DStringAppend(&ds, sym1, -1);
      *proc1Ptr = (Tcl_PackageInitProc *) GetProcAddress(handle, sym1);
      Tcl_DStringFree(&ds);
    }
    
    *proc2Ptr = (Tcl_PackageInitProc *) GetProcAddress(handle, sym2);
    if (*proc2Ptr == NULL) {
      Tcl_DStringAppend(&ds, "_", 1);
      sym2 = Tcl_DStringAppend(&ds, sym2, -1);
      *proc2Ptr = (Tcl_PackageInitProc *) GetProcAddress(handle, sym2);
      Tcl_DStringFree(&ds);
    }
    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:
 *    Code removed from memory.
 *
 *----------------------------------------------------------------------
 */

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

    handle = (HINSTANCE) clientData;
    FreeLibrary(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)
    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;
}

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