#endif
#include "tclInt.h"
#ifdef __WIN32__
#   include "tclWinInt.h"
#endif
#include "tclFileSystem.h"

/*
 * struct FilesystemRecord --
 *
 * A filesystem record is used to keep track of each filesystem currently
 * registered with the core, in a linked list.
 */

typedef struct FilesystemRecord {
    ClientData clientData;	/* Client specific data for the new filesystem
				 * (can be NULL) */
    const Tcl_Filesystem *fsPtr;/* Pointer to filesystem dispatch table. */
    struct FilesystemRecord *nextPtr;
				/* The next filesystem registered to Tcl, or
				 * NULL if no more. */
    struct FilesystemRecord *prevPtr;
				/* The previous filesystem registered to Tcl,
				 * or NULL if no more. */
} FilesystemRecord;

/*
 * This structure holds per-thread private copy of the current directory
 * maintained by the global cwdPathPtr. This structure holds per-thread
 * private copies of some global data. This way we avoid most of the
 * synchronization calls which boosts performance, at cost of having to update
 * this information each time the corresponding epoch counter changes.
 */

typedef struct ThreadSpecificData {
    int initialized;
    int cwdPathEpoch;
    int filesystemEpoch;
    Tcl_Obj *cwdPathPtr;
    ClientData cwdClientData;
    FilesystemRecord *filesystemList;
    int claims;
} ThreadSpecificData;

/*
 * Prototypes for functions defined later in this file.
 */

static int		EvalFileCallback(ClientData data[],
			    Tcl_Interp *interp, int result);
static FilesystemRecord*FsGetFirstFilesystem(void);
static void		FsThrExitProc(ClientData cd);
static Tcl_Obj *	FsListMounts(Tcl_Obj *pathPtr, const char *pattern);
static void		FsAddMountsToGlobResult(Tcl_Obj *resultPtr,
			    Tcl_Obj *pathPtr, const char *pattern,
			    Tcl_GlobTypeData *types);
static void		FsUpdateCwd(Tcl_Obj *cwdObj, ClientData clientData);

static void		FsRecacheFilesystemList(void);
static void		Claim(void);
static void		Disclaim(void);

static void *		DivertFindSymbol(Tcl_Interp *interp,
			    Tcl_LoadHandle loadHandle, const char *symbol);
static void		DivertUnloadFile(Tcl_LoadHandle loadHandle);

/*
 * These form part of the native filesystem support. They are needed here
 * because we have a few native filesystem functions (which are the same for

 * We initialize the record so that it thinks one file uses it. This means it
 * will never be freed.
 */

static FilesystemRecord nativeFilesystemRecord = {
    NULL,
    &tclNativeFilesystem,

    NULL,
    NULL
};

/*
 * This is incremented each time we modify the linked list of filesystems. Any
 * time it changes, all cached filesystem representations are suspect and must
 * be freed. For multithreading builds, change of the filesystem epoch will
 * trigger cache cleanup in all threads.
 */

static int theFilesystemEpoch = 1;

/*
 * Stores the linked list of filesystems. A 1:1 copy of this list is also
 * maintained in the TSD for each thread. This is to avoid synchronization
 * issues.
 */

static FilesystemRecord *filesystemList = &nativeFilesystemRecord;
TCL_DECLARE_MUTEX(filesystemMutex)

/*
 * Used to implement Tcl_FSGetCwd in a file-system independent way.
 */

static Tcl_Obj *cwdPathPtr = NULL;
static int cwdPathEpoch = 0;
static ClientData cwdClientData = NULL;
TCL_DECLARE_MUTEX(cwdMutex)

static Tcl_ThreadDataKey fsDataKey;

/*
 * One of these structures is used each time we successfully load a file from
 * a file system by way of making a temporary copy of the file on the native
 * filesystem. We need to store both the actual unloadProc/clientData
 * combination which was used, and the original and modified filenames, so
 * that we can correctly undo the entire operation when we want to unload the

{
    Tcl_Obj *cwd = Tcl_FSGetCwd(interp);

    if (cwd == NULL) {
	return NULL;
    }
    Tcl_DStringInit(cwdPtr);
    TclDStringAppendObj(cwdPtr, cwd);
    Tcl_DecrRefCount(cwd);
    return Tcl_DStringValue(cwdPtr);
}

/* Obsolete */
int
Tcl_EvalFile(

    /*
     * Trash the filesystems cache.
     */

    fsRecPtr = tsdPtr->filesystemList;
    while (fsRecPtr != NULL) {
	tmpFsRecPtr = fsRecPtr->nextPtr;
	fsRecPtr->fsPtr = NULL;
	ckfree(fsRecPtr);

	fsRecPtr = tmpFsRecPtr;
    }
    tsdPtr->initialized = 0;
}

int
TclFSCwdIsNative(void)
{
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&fsDataKey);

    if (tsdPtr->cwdClientData != NULL) {
	return 1;
    } else {
	return 0;
    }
}

 *----------------------------------------------------------------------
 */

int
TclFSCwdPointerEquals(
    Tcl_Obj **pathPtrPtr)
{
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&fsDataKey);

    Tcl_MutexLock(&cwdMutex);
    if (tsdPtr->cwdPathPtr == NULL
	    || tsdPtr->cwdPathEpoch != cwdPathEpoch) {
	if (tsdPtr->cwdPathPtr != NULL) {
	    Tcl_DecrRefCount(tsdPtr->cwdPathPtr);
	}

	    return 1;
	} else {
	    return 0;
	}
    }
}


static void
FsRecacheFilesystemList(void)
{
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&fsDataKey);
    FilesystemRecord *fsRecPtr, *tmpFsRecPtr = NULL, *toFree = NULL, *list;

    /*
     * Trash the current cache.
     */

    fsRecPtr = tsdPtr->filesystemList;
    while (fsRecPtr != NULL) {
	tmpFsRecPtr = fsRecPtr->nextPtr;
	fsRecPtr->nextPtr = toFree;
	toFree = fsRecPtr;

	fsRecPtr = tmpFsRecPtr;
    }


    /*



     * Locate tail of the global filesystem list.
     */

    Tcl_MutexLock(&filesystemMutex);
    fsRecPtr = filesystemList;
    while (fsRecPtr != NULL) {
	tmpFsRecPtr = fsRecPtr;
	fsRecPtr = fsRecPtr->nextPtr;
    }

    /*
     * Refill the cache honouring the order.
     */

    list = NULL;
    fsRecPtr = tmpFsRecPtr;
    while (fsRecPtr != NULL) {
	tmpFsRecPtr = ckalloc(sizeof(FilesystemRecord));
	*tmpFsRecPtr = *fsRecPtr;
	tmpFsRecPtr->nextPtr = list;
	tmpFsRecPtr->prevPtr = NULL;

	list = tmpFsRecPtr;
	fsRecPtr = fsRecPtr->prevPtr;
    }
    tsdPtr->filesystemList = list;
    tsdPtr->filesystemEpoch = theFilesystemEpoch;
    Tcl_MutexUnlock(&filesystemMutex);

    while (toFree) {
	FilesystemRecord *next = toFree->nextPtr;
	toFree->fsPtr = NULL;
	ckfree(toFree);
	toFree = next;
    }

    /*
     * Make sure the above gets released on thread exit.
     */

    if (tsdPtr->initialized == 0) {
	Tcl_CreateThreadExitHandler(FsThrExitProc, tsdPtr);
	tsdPtr->initialized = 1;
    }
}


static FilesystemRecord *
FsGetFirstFilesystem(void)
{
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&fsDataKey);







    if (tsdPtr->filesystemList == NULL || ((tsdPtr->claims == 0)
	    && (tsdPtr->filesystemEpoch != theFilesystemEpoch))) {
	FsRecacheFilesystemList();

    }

    return tsdPtr->filesystemList;


}

/*
 * The epoch can be changed both by filesystems being added or removed and by
 * env(HOME) changing.
 */

int
TclFSEpochOk(
    int filesystemEpoch)
{
    return (filesystemEpoch == 0 || filesystemEpoch == theFilesystemEpoch);
}

static void
Claim()
{
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&fsDataKey);
    tsdPtr->claims++;
}

static void
Disclaim()
{
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&fsDataKey);
    tsdPtr->claims--;
}

int
TclFSEpoch()
{
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&fsDataKey);
    return tsdPtr->filesystemEpoch;
}


/*
 * If non-NULL, clientData is owned by us and must be freed later.
 */

static void
FsUpdateCwd(
    Tcl_Obj *cwdObj,
    ClientData clientData)
{
    int len;
    const char *str = NULL;
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&fsDataKey);

    if (cwdObj != NULL) {
	str = Tcl_GetStringFromObj(cwdObj, &len);
    }

    Tcl_MutexLock(&cwdMutex);
    if (cwdPathPtr != NULL) {

     * needed.
     */

    fsRecPtr = filesystemList;
    while (fsRecPtr != NULL) {
	FilesystemRecord *tmpFsRecPtr = fsRecPtr->nextPtr;



	/* The native filesystem is static, so we don't free it. */


	if (fsRecPtr != &nativeFilesystemRecord) {
	    ckfree(fsRecPtr);

	}
	fsRecPtr = tmpFsRecPtr;
    }
    theFilesystemEpoch++;
    filesystemList = NULL;

    /*
     * Now filesystemList is NULL. This means that any attempt to use the
     * filesystem is likely to fail.
     */

 *----------------------------------------------------------------------
 */

void
TclResetFilesystem(void)
{
    filesystemList = &nativeFilesystemRecord;
    theFilesystemEpoch++;





#ifdef __WIN32__
    /*
     * Cleans up the win32 API filesystem proc lookup table. This must happen
     * very late in finalization so that deleting of copied dlls can occur.
     */

    }

    newFilesystemPtr = ckalloc(sizeof(FilesystemRecord));

    newFilesystemPtr->clientData = clientData;
    newFilesystemPtr->fsPtr = fsPtr;








    /*
     * Is this lock and wait strictly speaking necessary? Since any iterators
     * out there will have grabbed a copy of the head of the list and be
     * iterating away from that, if we add a new element to the head of the
     * list, it can't possibly have any effect on any of their loops. In fact
     * it could be better not to wait, since we are adjusting the filesystem
     * epoch, any cached representations calculated by existing iterators are

    /*
     * Traverse the 'filesystemList' looking for the particular node whose
     * 'fsPtr' member matches 'fsPtr' and remove that one from the list.
     * Ensure that the "default" node cannot be removed.
     */

    fsRecPtr = filesystemList;
    while ((retVal == TCL_ERROR) && (fsRecPtr != &nativeFilesystemRecord)) {
	if (fsRecPtr->fsPtr == fsPtr) {
	    if (fsRecPtr->prevPtr) {
		fsRecPtr->prevPtr->nextPtr = fsRecPtr->nextPtr;
	    } else {
		filesystemList = fsRecPtr->nextPtr;
	    }
	    if (fsRecPtr->nextPtr) {
		fsRecPtr->nextPtr->prevPtr = fsRecPtr->prevPtr;
	    }

	    /*
	     * Increment the filesystem epoch counter, since existing paths
	     * might conceivably now belong to different filesystems. This
	     * should also ensure that paths which have cached the filesystem
	     * which is about to be deleted do not reference that filesystem
	     * (which would of course lead to memory exceptions).
	     */

	    theFilesystemEpoch++;



	    ckfree(fsRecPtr);


	    retVal = TCL_OK;
	} else {
	    fsRecPtr = fsRecPtr->nextPtr;
	}
    }

 *---------------------------------------------------------------------------
 */

int
TclFSNormalizeToUniquePath(
    Tcl_Interp *interp,		/* Used for error messages. */
    Tcl_Obj *pathPtr,		/* The path to normalize in place. */
    int startAt)		/* Start at this char-offset. */



{
    FilesystemRecord *fsRecPtr, *firstFsRecPtr;



    /*
     * Call each of the "normalise path" functions in succession. This is a
     * special case, in which if we have a native filesystem handler, we call
     * it first. This is because the root of Tcl's filesystem is always a
     * native filesystem (i.e. '/' on unix is native).
     */

    firstFsRecPtr = FsGetFirstFilesystem();

    Claim();
    for (fsRecPtr=firstFsRecPtr; fsRecPtr!=NULL; fsRecPtr=fsRecPtr->nextPtr) {
	if (fsRecPtr->fsPtr != &tclNativeFilesystem) {
	    continue;
	}

	/*
	 * TODO: Assume that we always find the native file system; it should

	/*
	 * We could add an efficiency check like this:
	 *		if (retVal == length-of(pathPtr)) {break;}
	 * but there's not much benefit.
	 */
    }
    Disclaim();

    return startAt;
}

/*
 *---------------------------------------------------------------------------
 *

 *----------------------------------------------------------------------
 */

Tcl_Obj *
Tcl_FSGetCwd(
    Tcl_Interp *interp)
{
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&fsDataKey);

    if (TclFSCwdPointerEquals(NULL)) {
	FilesystemRecord *fsRecPtr;
	Tcl_Obj *retVal = NULL;

	/*
	 * We've never been called before, try to find a cwd. Call each of the
	 * "Tcl_GetCwd" function in succession. A non-NULL return value
	 * indicates the particular function has succeeded.
	 */

	fsRecPtr = FsGetFirstFilesystem();
	Claim();
	for (; (retVal == NULL) && (fsRecPtr != NULL);
		fsRecPtr = fsRecPtr->nextPtr) {
	    ClientData retCd;
	    TclFSGetCwdProc2 *proc2;
	    if (fsRecPtr->fsPtr->getCwdProc == NULL) {
		continue;
	    }

		/*
		 * Looks like a new current directory.
		 */

		retVal = fsRecPtr->fsPtr->internalToNormalizedProc(retCd);
		Tcl_IncrRefCount(retVal);
		norm = TclFSNormalizeAbsolutePath(interp,retVal);
		if (norm != NULL) {
		    /*
		     * We found a cwd, which is now in our global storage. We
		     * must make a copy. Norm already has a refCount of 1.
		     *
		     * Threading issue: note that multiple threads at system
		     * startup could in principle call this function
		     * simultaneously. They will therefore each set the
		     * cwdPathPtr independently. That behaviour is a bit
		     * peculiar, but should be fine. Once we have a cwd, we'll
		     * always be in the 'else' branch below which is simpler.
		     */

		    FsUpdateCwd(norm, retCd);
		    Tcl_DecrRefCount(norm);
		} else {
		    fsRecPtr->fsPtr->freeInternalRepProc(retCd);
		}
		Tcl_DecrRefCount(retVal);
		retVal = NULL;
		Disclaim();
		goto cdDidNotChange;
	    } else if (interp != NULL) {
		Tcl_AppendResult(interp,
			"error getting working directory name: ",
			Tcl_PosixError(interp), NULL);
	    }
	}
	Disclaim();

	/*
	 * Now the 'cwd' may NOT be normalized, at least on some platforms.
	 * For the sake of efficiency, we want a completely normalized cwd at
	 * all times.
	 *
	 * Finally, if retVal is NULL, we do not have a cwd, which could be
	 * problematic.
	 */

	if (retVal != NULL) {
	    Tcl_Obj *norm = TclFSNormalizeAbsolutePath(interp, retVal);

	    if (norm != NULL) {
		/*
		 * We found a cwd, which is now in our global storage. We must
		 * make a copy. Norm already has a refCount of 1.
		 *
		 * Threading issue: note that multiple threads at system

	    goto cdDidNotChange;
	}

	/*
	 * Normalize the path.
	 */

	norm = TclFSNormalizeAbsolutePath(interp, retVal);

	/*
	 * Check whether cwd has changed from the value previously stored in
	 * cwdPathPtr. Really 'norm' shouldn't be NULL, but we are careful.
	 */

	if (norm == NULL) {

	     * again here. On Unix it might actually be true that we always
	     * have the correct form in the native rep in which case we could
	     * simply use:
	     *		cd = Tcl_FSGetNativePath(pathPtr);
	     * instead. This should be examined by someone on Unix.
	     */

	    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&fsDataKey);
	    ClientData cd;
	    ClientData oldcd = tsdPtr->cwdClientData;

	    /*
	     * Assumption we are using a filesystem version 2.
	     */

     * Call each of the "listVolumes" function in succession. A non-NULL
     * return value indicates the particular function has succeeded. We call
     * all the functions registered, since we want a list of all drives from
     * all filesystems.
     */

    fsRecPtr = FsGetFirstFilesystem();
    Claim();
    while (fsRecPtr != NULL) {
	if (fsRecPtr->fsPtr->listVolumesProc != NULL) {
	    Tcl_Obj *thisFsVolumes = fsRecPtr->fsPtr->listVolumesProc();

	    if (thisFsVolumes != NULL) {
		Tcl_ListObjAppendList(NULL, resultPtr, thisFsVolumes);
		Tcl_DecrRefCount(thisFsVolumes);
	    }
	}
	fsRecPtr = fsRecPtr->nextPtr;
    }
    Disclaim();

    return resultPtr;
}

/*
 *---------------------------------------------------------------------------
 *

     * Call each of the "matchInDirectory" functions in succession, with the
     * specific type information 'mountsOnly'. A non-NULL return value
     * indicates the particular function has succeeded. We call all the
     * functions registered, since we want a list from each filesystems.
     */

    fsRecPtr = FsGetFirstFilesystem();
    Claim();
    while (fsRecPtr != NULL) {
	if (fsRecPtr->fsPtr != &tclNativeFilesystem &&
		fsRecPtr->fsPtr->matchInDirectoryProc != NULL) {
	    if (resultPtr == NULL) {
		resultPtr = Tcl_NewObj();
	    }
	    fsRecPtr->fsPtr->matchInDirectoryProc(NULL, resultPtr, pathPtr,
		    pattern, &mountsOnly);
	}
	fsRecPtr = fsRecPtr->nextPtr;
    }
    Disclaim();

    return resultPtr;
}

/*
 *---------------------------------------------------------------------------
 *

     */

    if (lenPtr != NULL) {
	TclListObjLength(NULL, result, lenPtr);
    }
    return result;
}

























/*
 *----------------------------------------------------------------------
 *
 * TclGetPathType --
 *
 *	Helper function used by FSGetPathType.
 *

    /*
     * Call each of the "listVolumes" function in succession, checking whether
     * the given path is an absolute path on any of the volumes returned (this
     * is done by checking whether the path's prefix matches).
     */

    fsRecPtr = FsGetFirstFilesystem();
    Claim();
    while (fsRecPtr != NULL) {
	/*
	 * We want to skip the native filesystem in this loop because
	 * otherwise we won't necessarily pass all the Tcl testsuite - this is
	 * because some of the tests artificially change the current platform
	 * (between win, unix) but the list of volumes we get by calling
	 * fsRecPtr->fsPtr->listVolumesProc will reflect the current (real)

		    break;
		}
	    }
	}
	fsRecPtr = fsRecPtr->nextPtr;
    }
    Disclaim();
    return type;
}

/*
 *---------------------------------------------------------------------------
 *
 * Tcl_FSRenameFile --

     * Check if the filesystem has changed in some way since this object's
     * internal representation was calculated. Before doing that, assure we
     * have the most up-to-date copy of the master filesystem. This is
     * accomplished by the FsGetFirstFilesystem() call.
     */

    fsRecPtr = FsGetFirstFilesystem();
    Claim();

    if (TclFSEnsureEpochOk(pathPtr, &retVal) != TCL_OK) {
	Disclaim();
	return NULL;
    } else if (retVal != NULL) {
	/* TODO: Can this happen? */
	Disclaim();
	return retVal;
    }

    /*
     * Call each of the "pathInFilesystem" functions in succession. A
     * non-return value of -1 indicates the particular function has succeeded.
     */

	if (fsRecPtr->fsPtr->pathInFilesystemProc(pathPtr, &clientData)!=-1) {
	    /*
	     * We assume the type of pathPtr hasn't been changed by the above
	     * call to the pathInFilesystemProc.
	     */

	    TclFSSetPathDetails(pathPtr, fsRecPtr->fsPtr, clientData);
	    Disclaim();
	    return fsRecPtr->fsPtr;
	}
    }
    Disclaim();

    return NULL;
}

/*
 *---------------------------------------------------------------------------
 *