Tcl Source Code

/*
 * tclLoad.c --
 *
 *	This file provides the generic portion (those that are the same on all
 *	platforms) of Tcl's dynamic loading facilities.
 *
 * Copyright © 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.
 */

#include "tclInt.h"


/*
 * The following structure describes a library that has been loaded either
 * dynamically (with the "load" command) or statically (as indicated by a call
 * to Tcl_StaticLibrary). All such libraries are linked together into a
 * single list for the process. Library are never unloaded, until the
 * application exits, when TclFinalizeLoad is called, and these structures are

				 * for end of list. */
} InterpLibrary;

/*
 * Prototypes for functions that are private to this file:
 */

static void	LoadCleanupProc(ClientData clientData,
		    Tcl_Interp *interp);
static int	UnloadLibrary(Tcl_Interp *interp, Tcl_Interp *target,
		    LoadedLibrary *library, int keepLibrary,
		    const char *fullFileName);


/*
 *----------------------------------------------------------------------
 *
 * Tcl_LoadObjCmd --
 *
 *	This function is invoked to process the "load" Tcl command. See the

    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    Tcl_Interp *target;		/* Which interpreter to unload from. */
    LoadedLibrary *libraryPtr, *defaultPtr;
    Tcl_DString pfx, tmp;

    InterpLibrary *ipFirstPtr, *ipPtr;
    int i, index, code, complain = 1, keepLibrary = 0;

    const char *fullFileName = "";
    const char *prefix;
    static const char *const options[] = {
	"-nocomplain", "-keeplibrary", "--", NULL
    };
    enum unloadOptionsEnum {
	UNLOAD_NOCOMPLAIN, UNLOAD_KEEPLIB, UNLOAD_LAST

		fullFileName));
	Tcl_SetErrorCode(interp, "TCL", "OPERATION", "UNLOAD", "NEVERLOADED",
		NULL);
	code = TCL_ERROR;
	goto done;
    }

    code = UnloadLibrary(interp, target, libraryPtr, keepLibrary, fullFileName);

  done:
    Tcl_DStringFree(&pfx);
    Tcl_DStringFree(&tmp);
    if (!complain && (code != TCL_OK)) {
	code = TCL_OK;
	Tcl_ResetResult(interp);
    }
    return code;
}

static int
UnloadLibrary(
	Tcl_Interp *interp,
	Tcl_Interp *target,
	LoadedLibrary *libraryPtr,
	int keepLibrary,
	const char *fullFileName
)
{
    int code;
    InterpLibrary *ipFirstPtr, *ipPtr;
    LoadedLibrary *defaultPtr;
    int trustedRefCount, safeRefCount;
    Tcl_LibraryUnloadProc *unloadProc;

    /*
     * Ensure that the DLL can be unloaded. If it is a trusted interpreter,
     * libraryPtr->unloadProc must not be NULL for the DLL to be unloadable. If
     * the interpreter is a safe one, libraryPtr->safeUnloadProc must be non-NULL.
     */

    if (Tcl_IsSafe(target)) {

	    Tcl_SetErrorCode(interp, "TCL", "OPERATION", "UNLOAD", "CANNOT",
		    NULL);
	    code = TCL_ERROR;
	    goto done;
	}
	unloadProc = libraryPtr->unloadProc;
    }




    /*
     * We are ready to unload the library. First, evaluate the unload
     * function. If this fails, we cannot proceed with unload. Also, we must
     * specify the proper flag to pass to the unload callback.
     * TCL_UNLOAD_DETACH_FROM_INTERPRETER is defined when the callback should
     * only remove itself from the interpreter; the library will be unloaded

			    ipPrevPtr = ipPtr, ipPtr = ipPtr->nextPtr) {
			if (ipPtr->libraryPtr == defaultPtr) {
			    ipPrevPtr->nextPtr = ipPtr->nextPtr;
			    break;
			}
		    }
		}
		Tcl_SetAssocData(target, "tclLoad", LoadCleanupProc, ipFirstPtr);

		ckfree(defaultPtr->fileName);
		ckfree(defaultPtr->prefix);
		ckfree(defaultPtr);
		ckfree(ipPtr);
		Tcl_MutexUnlock(&libraryMutex);
	    } else {
		code = TCL_ERROR;
	    }
	}
#else
	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		"file \"%s\" cannot be unloaded: unloading disabled",
		fullFileName));
	Tcl_SetErrorCode(interp, "TCL", "OPERATION", "UNLOAD", "DISABLED",
		NULL);
	code = TCL_ERROR;
#endif
    }

  done:






    return code;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_StaticLibrary --