275 lines
7.2 KiB
C
275 lines
7.2 KiB
C
/*
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* tclLoadDl.c --
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*
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* This procedure provides a version of the TclLoadFile that works with
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* the "dlopen" and "dlsym" library procedures for dynamic loading.
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*
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* Copyright (c) 1995-1997 Sun Microsystems, Inc.
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*
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* See the file "license.terms" for information on usage and redistribution
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* of this file, and for a DISCLAIMER OF ALL WARRANTIES.
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*/
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#include "tclInt.h"
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#ifdef NO_DLFCN_H
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# include "../compat/dlfcn.h"
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#else
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# include <dlfcn.h>
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#endif
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/*
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* In some systems, like SunOS 4.1.3, the RTLD_NOW flag isn't defined and this
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* argument to dlopen must always be 1. The RTLD_LOCAL flag doesn't exist on
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* some platforms; if it doesn't exist, set it to 0 so it has no effect.
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* See [Bug #3216070]
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*/
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#ifndef RTLD_NOW
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# define RTLD_NOW 1
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#endif
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#ifndef RTLD_LOCAL
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# define RTLD_LOCAL 0
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#endif
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/*
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* Static procedures defined within this file.
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*/
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static void * FindSymbol(Tcl_Interp *interp,
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Tcl_LoadHandle loadHandle, const char *symbol);
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static void UnloadFile(Tcl_LoadHandle loadHandle);
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/*
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*---------------------------------------------------------------------------
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*
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* TclpDlopen --
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*
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* Dynamically loads a binary code file into memory and returns a handle
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* to the new code.
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*
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* Results:
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* A standard Tcl completion code. If an error occurs, an error message
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* is left in the interp's result.
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*
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* Side effects:
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* New code suddenly appears in memory.
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*
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*---------------------------------------------------------------------------
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*/
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int
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TclpDlopen(
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Tcl_Interp *interp, /* Used for error reporting. */
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Tcl_Obj *pathPtr, /* Name of the file containing the desired
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* code (UTF-8). */
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Tcl_LoadHandle *loadHandle, /* Filled with token for dynamically loaded
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* file which will be passed back to
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* (*unloadProcPtr)() to unload the file. */
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Tcl_FSUnloadFileProc **unloadProcPtr,
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/* Filled with address of Tcl_FSUnloadFileProc
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* function which should be used for this
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* file. */
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int flags)
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{
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void *handle;
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Tcl_LoadHandle newHandle;
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const char *native;
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int dlopenflags = 0;
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/*
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* First try the full path the user gave us. This is particularly
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* important if the cwd is inside a vfs, and we are trying to load using a
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* relative path.
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*/
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native = Tcl_FSGetNativePath(pathPtr);
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/*
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* Use (RTLD_NOW|RTLD_LOCAL) as default, see [Bug #3216070]
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*/
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if (flags & TCL_LOAD_GLOBAL) {
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dlopenflags |= RTLD_GLOBAL;
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} else {
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dlopenflags |= RTLD_LOCAL;
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}
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if (flags & TCL_LOAD_LAZY) {
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dlopenflags |= RTLD_LAZY;
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} else {
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dlopenflags |= RTLD_NOW;
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}
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handle = dlopen(native, dlopenflags);
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if (handle == NULL) {
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/*
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* Let the OS loader examine the binary search path for whatever
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* string the user gave us which hopefully refers to a file on the
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* binary path.
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*/
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Tcl_DString ds;
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const char *fileName = Tcl_GetString(pathPtr);
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native = Tcl_UtfToExternalDString(NULL, fileName, -1, &ds);
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/*
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* Use (RTLD_NOW|RTLD_LOCAL) as default, see [Bug #3216070]
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*/
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handle = dlopen(native, dlopenflags);
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Tcl_DStringFree(&ds);
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}
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if (handle == NULL) {
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/*
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* Write the string to a variable first to work around a compiler bug
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* in the Sun Forte 6 compiler. [Bug 1503729]
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*/
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const char *errorStr = dlerror();
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if (interp) {
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Tcl_SetObjResult(interp, Tcl_ObjPrintf(
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"couldn't load file \"%s\": %s",
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Tcl_GetString(pathPtr), errorStr));
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}
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return TCL_ERROR;
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}
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newHandle = ckalloc(sizeof(*newHandle));
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newHandle->clientData = handle;
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newHandle->findSymbolProcPtr = &FindSymbol;
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newHandle->unloadFileProcPtr = &UnloadFile;
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*unloadProcPtr = &UnloadFile;
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*loadHandle = newHandle;
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return TCL_OK;
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}
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/*
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*----------------------------------------------------------------------
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*
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* FindSymbol --
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*
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* Looks up a symbol, by name, through a handle associated with a
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* previously loaded piece of code (shared library).
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*
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* Results:
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* Returns a pointer to the function associated with 'symbol' if it is
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* found. Otherwise returns NULL and may leave an error message in the
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* interp's result.
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*
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*----------------------------------------------------------------------
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*/
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static void *
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FindSymbol(
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Tcl_Interp *interp, /* Place to put error messages. */
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Tcl_LoadHandle loadHandle, /* Value from TcpDlopen(). */
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const char *symbol) /* Symbol to look up. */
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{
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const char *native; /* Name of the library to be loaded, in
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* system encoding */
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Tcl_DString newName, ds; /* Buffers for converting the name to
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* system encoding and prepending an
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* underscore*/
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void *handle = (void *) loadHandle->clientData;
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/* Native handle to the loaded library */
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void *proc; /* Address corresponding to the resolved
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* symbol */
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/*
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* Some platforms still add an underscore to the beginning of symbol
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* names. If we can't find a name without an underscore, try again with
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* the underscore.
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*/
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native = Tcl_UtfToExternalDString(NULL, symbol, -1, &ds);
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proc = dlsym(handle, native); /* INTL: Native. */
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if (proc == NULL) {
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Tcl_DStringInit(&newName);
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TclDStringAppendLiteral(&newName, "_");
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native = Tcl_DStringAppend(&newName, native, -1);
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proc = dlsym(handle, native); /* INTL: Native. */
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Tcl_DStringFree(&newName);
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}
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Tcl_DStringFree(&ds);
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if (proc == NULL) {
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const char *errorStr = dlerror();
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if (interp) {
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if (!errorStr) {
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errorStr = "unknown";
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}
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Tcl_SetObjResult(interp, Tcl_ObjPrintf(
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"cannot find symbol \"%s\": %s", symbol, errorStr));
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Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "LOAD_SYMBOL", symbol,
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NULL);
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}
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}
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return proc;
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}
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/*
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*----------------------------------------------------------------------
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*
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* UnloadFile --
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*
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* Unloads a dynamically loaded binary code file from memory. Code
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* pointers in the formerly loaded file are no longer valid after calling
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* this function.
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*
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* Results:
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* None.
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*
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* Side effects:
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* Code removed from memory.
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*
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*----------------------------------------------------------------------
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*/
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static void
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UnloadFile(
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Tcl_LoadHandle loadHandle) /* loadHandle returned by a previous call to
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* TclpDlopen(). The loadHandle is a token
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* that represents the loaded file. */
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{
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void *handle = loadHandle->clientData;
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dlclose(handle);
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ckfree(loadHandle);
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}
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/*
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*----------------------------------------------------------------------
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*
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* TclGuessPackageName --
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*
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* If the "load" command is invoked without providing a package name,
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* this procedure is invoked to try to figure it out.
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*
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* Results:
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* Always returns 0 to indicate that we couldn't figure out a package
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* name; generic code will then try to guess the package from the file
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* name. A return value of 1 would have meant that we figured out the
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* package name and put it in bufPtr.
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*
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* Side effects:
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* None.
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*
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*----------------------------------------------------------------------
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*/
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int
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TclGuessPackageName(
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const char *fileName, /* Name of file containing package (already
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* translated to local form if needed). */
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Tcl_DString *bufPtr) /* Initialized empty dstring. Append package
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* name to this if possible. */
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{
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return 0;
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}
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/*
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* Local Variables:
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* mode: c
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* c-basic-offset: 4
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* fill-column: 78
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* End:
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*/
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