tclLoad.c from Gdb at Krugle
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/*
* tclLoad.c --
*
* This file provides the generic portion (those that are the same
* on all platforms) of Tcl's dynamic loading facilities.
*
* 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: tclLoad.c,v 1.8 2002/07/22 16:51:48 vincentdarley Exp $
*/
#include "tclInt.h"
/*
* The following structure describes a package that has been loaded
* either dynamically (with the "load" command) or statically (as
* indicated by a call to TclGetLoadedPackages). All such packages
* are linked together into a single list for the process. Packages
* are never unloaded, until the application exits, when
* TclFinalizeLoad is called, and these structures are freed.
*/
typedef struct LoadedPackage {
char *fileName; /* Name of the file from which the
* package was loaded. An empty string
* means the package is loaded statically.
* Malloc-ed. */
char *packageName; /* Name of package prefix for the package,
* properly capitalized (first letter UC,
* others LC), no "_", as in "Net".
* Malloc-ed. */
Tcl_LoadHandle loadHandle; /* Token for the loaded file which should be
* passed to (*unLoadProcPtr)() when the file
* is no longer needed. If fileName is NULL,
* then this field is irrelevant. */
Tcl_PackageInitProc *initProc;
/* Initialization procedure to call to
* incorporate this package into a trusted
* interpreter. */
Tcl_PackageInitProc *safeInitProc;
/* Initialization procedure to call to
* incorporate this package into a safe
* interpreter (one that will execute
* untrusted scripts). NULL means the
* package can't be used in unsafe
* interpreters. */
Tcl_FSUnloadFileProc *unLoadProcPtr;
/* Procedure to use to unload this package.
* If NULL, then we do not attempt to unload
* the package. If fileName is NULL, then
* this field is irrelevant. */
struct LoadedPackage *nextPtr;
/* Next in list of all packages loaded into
* this application process. NULL means
* end of list. */
} LoadedPackage;
/*
* TCL_THREADS
* There is a global list of packages that is anchored at firstPackagePtr.
* Access to this list is governed by a mutex.
*/
static LoadedPackage *firstPackagePtr = NULL;
/* First in list of all packages loaded into
* this process. */
TCL_DECLARE_MUTEX(packageMutex)
/*
* The following structure represents a particular package that has
* been incorporated into a particular interpreter (by calling its
* initialization procedure). There is a list of these structures for
* each interpreter, with an AssocData value (key "load") for the
* interpreter that points to the first package (if any).
*/
typedef struct InterpPackage {
LoadedPackage *pkgPtr; /* Points to detailed information about
* package. */
struct InterpPackage *nextPtr;
/* Next package in this interpreter, or
* NULL for end of list. */
} InterpPackage;
/*
* Prototypes for procedures that are private to this file:
*/
static void LoadCleanupProc _ANSI_ARGS_((ClientData clientData,
Tcl_Interp *interp));
/*
*----------------------------------------------------------------------
*
* Tcl_LoadObjCmd --
*
* This procedure is invoked to process the "load" Tcl command.
* See the user documentation for details on what it does.
*
* Results:
* A standard Tcl result.
*
* Side effects:
* See the user documentation.
*
*----------------------------------------------------------------------
*/
int
Tcl_LoadObjCmd(dummy, interp, objc, objv)
ClientData dummy; /* Not used. */
Tcl_Interp *interp; /* Current interpreter. */
int objc; /* Number of arguments. */
Tcl_Obj *CONST objv[]; /* Argument objects. */
{
Tcl_Interp *target;
LoadedPackage *pkgPtr, *defaultPtr;
Tcl_DString pkgName, tmp, initName, safeInitName;
Tcl_PackageInitProc *initProc, *safeInitProc;
InterpPackage *ipFirstPtr, *ipPtr;
int code, namesMatch, filesMatch;
char *p, *fullFileName, *packageName;
Tcl_LoadHandle loadHandle;
Tcl_FSUnloadFileProc *unLoadProcPtr = NULL;
Tcl_UniChar ch;
int offset;
if ((objc < 2) || (objc > 4)) {
Tcl_WrongNumArgs(interp, 1, objv, "fileName ?packageName? ?interp?");
return TCL_ERROR;
}
if (Tcl_FSConvertToPathType(interp, objv[1]) != TCL_OK) {
return TCL_ERROR;
}
fullFileName = Tcl_GetString(objv[1]);
Tcl_DStringInit(&pkgName);
Tcl_DStringInit(&initName);
Tcl_DStringInit(&safeInitName);
Tcl_DStringInit(&tmp);
packageName = NULL;
if (objc >= 3) {
packageName = Tcl_GetString(objv[2]);
if (packageName[0] == '\0') {
packageName = NULL;
}
}
if ((fullFileName[0] == 0) && (packageName == NULL)) {
Tcl_SetResult(interp,
"must specify either file name or package name",
TCL_STATIC);
code = TCL_ERROR;
goto done;
}
/*
* Figure out which interpreter we're going to load the package into.
*/
target = interp;
if (objc == 4) {
char *slaveIntName;
slaveIntName = Tcl_GetString(objv[3]);
target = Tcl_GetSlave(interp, slaveIntName);
if (target == NULL) {
return TCL_ERROR;
}
}
/*
* Scan through the packages that are currently loaded to see if the
* package we want is already loaded. We'll use a loaded package if
* it meets any of the following conditions:
* - Its name and file match the once we're looking for.
* - Its file matches, and we weren't given a name.
* - Its name matches, the file name was specified as empty, and there
* is only no statically loaded package with the same name.
*/
Tcl_MutexLock(&packageMutex);
defaultPtr = NULL;
for (pkgPtr = firstPackagePtr; pkgPtr != NULL; pkgPtr = pkgPtr->nextPtr) {
if (packageName == NULL) {
namesMatch = 0;
} else {
Tcl_DStringSetLength(&pkgName, 0);
Tcl_DStringAppend(&pkgName, packageName, -1);
Tcl_DStringSetLength(&tmp, 0);
Tcl_DStringAppend(&tmp, pkgPtr->packageName, -1);
Tcl_UtfToLower(Tcl_DStringValue(&pkgName));
Tcl_UtfToLower(Tcl_DStringValue(&tmp));
if (strcmp(Tcl_DStringValue(&tmp),
Tcl_DStringValue(&pkgName)) == 0) {
namesMatch = 1;
} else {
namesMatch = 0;
}
}
Tcl_DStringSetLength(&pkgName, 0);
filesMatch = (strcmp(pkgPtr->fileName, fullFileName) == 0);
if (filesMatch && (namesMatch || (packageName == NULL))) {
break;
}
if (namesMatch && (fullFileName[0] == 0)) {
defaultPtr = pkgPtr;
}
if (filesMatch && !namesMatch && (fullFileName[0] != 0)) {
/*
* Can't have two different packages loaded from the same
* file.
*/
Tcl_AppendResult(interp, "file \"", fullFileName,
"\" is already loaded for package \"",
pkgPtr->packageName, "\"", (char *) NULL);
code = TCL_ERROR;
Tcl_MutexUnlock(&packageMutex);
goto done;
}
}
Tcl_MutexUnlock(&packageMutex);
if (pkgPtr == NULL) {
pkgPtr = defaultPtr;
}
/*
* Scan through the list of packages already loaded in the target
* interpreter. If the package we want is already loaded there,
* then there's nothing for us to to.
*/
if (pkgPtr != NULL) {
ipFirstPtr = (InterpPackage *) Tcl_GetAssocData(target, "tclLoad",
(Tcl_InterpDeleteProc **) NULL);
for (ipPtr = ipFirstPtr; ipPtr != NULL; ipPtr = ipPtr->nextPtr) {
if (ipPtr->pkgPtr == pkgPtr) {
code = TCL_OK;
goto done;
}
}
}
if (pkgPtr == NULL) {
/*
* The desired file isn't currently loaded, so load it. It's an
* error if the desired package is a static one.
*/
if (fullFileName[0] == 0) {
Tcl_AppendResult(interp, "package \"", packageName,
"\" isn't loaded statically", (char *) NULL);
code = TCL_ERROR;
goto done;
}
/*
* Figure out the module name if it wasn't provided explicitly.
*/
if (packageName != NULL) {
Tcl_DStringAppend(&pkgName, packageName, -1);
} else {
int retc;
/*
* Threading note - this call used to be protected by a mutex.
*/
retc = TclGuessPackageName(fullFileName, &pkgName);
if (!retc) {
Tcl_Obj *splitPtr;
Tcl_Obj *pkgGuessPtr;
int pElements;
char *pkgGuess;
/*
* The platform-specific code couldn't figure out the
* module name. Make a guess by taking the last element
* of the file name, stripping off any leading "lib",
* and then using all of the alphabetic and underline
* characters that follow that.
*/
splitPtr = Tcl_FSSplitPath(objv[1], &pElements);
Tcl_ListObjIndex(NULL, splitPtr, pElements -1, &pkgGuessPtr);
pkgGuess = Tcl_GetString(pkgGuessPtr);
if ((pkgGuess[0] == 'l') && (pkgGuess[1] == 'i')
&& (pkgGuess[2] == 'b')) {
pkgGuess += 3;
}
for (p = pkgGuess; *p != 0; p += offset) {
offset = Tcl_UtfToUniChar(p, &ch);
if ((ch > 0x100)
|| !(isalpha(UCHAR(ch)) /* INTL: ISO only */
|| (UCHAR(ch) == '_'))) {
break;
}
}
if (p == pkgGuess) {
Tcl_DecrRefCount(splitPtr);
Tcl_AppendResult(interp,
"couldn't figure out package name for ",
fullFileName, (char *) NULL);
code = TCL_ERROR;
goto done;
}
Tcl_DStringAppend(&pkgName, pkgGuess, (p - pkgGuess));
Tcl_DecrRefCount(splitPtr);
}
}
/*
* Fix the capitalization in the package name so that the first
* character is in caps (or title case) but the others are all
* lower-case.
*/
Tcl_DStringSetLength(&pkgName,
Tcl_UtfToTitle(Tcl_DStringValue(&pkgName)));
/*
* Compute the names of the two initialization procedures,
* based on the package name.
*/
Tcl_DStringAppend(&initName, Tcl_DStringValue(&pkgName), -1);
Tcl_DStringAppend(&initName, "_Init", 5);
Tcl_DStringAppend(&safeInitName, Tcl_DStringValue(&pkgName), -1);
Tcl_DStringAppend(&safeInitName, "_SafeInit", 9);
/*
* Call platform-specific code to load the package and find the
* two initialization procedures.
*/
Tcl_MutexLock(&packageMutex);
code = Tcl_FSLoadFile(interp, objv[1], Tcl_DStringValue(&initName),
Tcl_DStringValue(&safeInitName), &initProc, &safeInitProc,
&loadHandle,&unLoadProcPtr);
Tcl_MutexUnlock(&packageMutex);
if (code != TCL_OK) {
goto done;
}
if (initProc == NULL) {
Tcl_AppendResult(interp, "couldn't find procedure ",
Tcl_DStringValue(&initName), (char *) NULL);
if (unLoadProcPtr != NULL) {
(*unLoadProcPtr)(loadHandle);
}
code = TCL_ERROR;
goto done;
}
/*
* Create a new record to describe this package.
*/
pkgPtr = (LoadedPackage *) ckalloc(sizeof(LoadedPackage));
pkgPtr->fileName = (char *) ckalloc((unsigned)
(strlen(fullFileName) + 1));
strcpy(pkgPtr->fileName, fullFileName);
pkgPtr->packageName = (char *) ckalloc((unsigned)
(Tcl_DStringLength(&pkgName) + 1));
strcpy(pkgPtr->packageName, Tcl_DStringValue(&pkgName));
pkgPtr->loadHandle = loadHandle;
pkgPtr->unLoadProcPtr = unLoadProcPtr;
pkgPtr->initProc = initProc;
pkgPtr->safeInitProc = safeInitProc;
Tcl_MutexLock(&packageMutex);
pkgPtr->nextPtr = firstPackagePtr;
firstPackagePtr = pkgPtr;
Tcl_MutexUnlock(&packageMutex);
}
/*
* Invoke the package's initialization procedure (either the
* normal one or the safe one, depending on whether or not the
* interpreter is safe).
*/
if (Tcl_IsSafe(target)) {
if (pkgPtr->safeInitProc != NULL) {
code = (*pkgPtr->safeInitProc)(target);
} else {
Tcl_AppendResult(interp,
"can't use package in a safe interpreter: ",
"no ", pkgPtr->packageName, "_SafeInit procedure",
(char *) NULL);
code = TCL_ERROR;
goto done;
}
} else {
code = (*pkgPtr->initProc)(target);
}
/*
* Record the fact that the package has been loaded in the
* target interpreter.
*/
if (code == TCL_OK) {
/*
* Refetch ipFirstPtr: loading the package may have introduced
* additional static packages at the head of the linked list!
*/
ipFirstPtr = (InterpPackage *) Tcl_GetAssocData(target, "tclLoad",
(Tcl_InterpDeleteProc **) NULL);
ipPtr = (InterpPackage *) ckalloc(sizeof(InterpPackage));
ipPtr->pkgPtr = pkgPtr;
ipPtr->nextPtr = ipFirstPtr;
Tcl_SetAssocData(target, "tclLoad", LoadCleanupProc,
(ClientData) ipPtr);
} else {
TclTransferResult(target, code, interp);
}
done:
Tcl_DStringFree(&pkgName);
Tcl_DStringFree(&initName);
Tcl_DStringFree(&safeInitName);
Tcl_DStringFree(&tmp);
return code;
}
/*
*----------------------------------------------------------------------
*
* Tcl_StaticPackage --
*
* This procedure is invoked to indicate that a particular
* package has been linked statically with an application.
*
* Results:
* None.
*
* Side effects:
* Once this procedure completes, the package becomes loadable
* via the "load" command with an empty file name.
*
*----------------------------------------------------------------------
*/
void
Tcl_StaticPackage(interp, pkgName, initProc, safeInitProc)
Tcl_Interp *interp; /* If not NULL, it means that the
* package has already been loaded
* into the given interpreter by
* calling the appropriate init proc. */
CONST char *pkgName; /* Name of package (must be properly
* capitalized: first letter upper
* case, others lower case). */
Tcl_PackageInitProc *initProc; /* Procedure to call to incorporate
* this package into a trusted
* interpreter. */
Tcl_PackageInitProc *safeInitProc; /* Procedure to call to incorporate
* this package into a safe interpreter
* (one that will execute untrusted
* scripts). NULL means the package
* can't be used in safe
* interpreters. */
{
LoadedPackage *pkgPtr;
InterpPackage *ipPtr, *ipFirstPtr;
/*
* Check to see if someone else has already reported this package as
* statically loaded. If this call is redundant then just return.
*/
Tcl_MutexLock(&packageMutex);
for (pkgPtr = firstPackagePtr; pkgPtr != NULL; pkgPtr = pkgPtr->nextPtr) {
if ((pkgPtr->initProc == initProc)
&& (pkgPtr->safeInitProc == safeInitProc)
&& (strcmp(pkgPtr->packageName, pkgName) == 0)) {
Tcl_MutexUnlock(&packageMutex);
return;
}
}
Tcl_MutexUnlock(&packageMutex);
pkgPtr = (LoadedPackage *) ckalloc(sizeof(LoadedPackage));
pkgPtr->fileName = (char *) ckalloc((unsigned) 1);
pkgPtr->fileName[0] = 0;
pkgPtr->packageName = (char *) ckalloc((unsigned)
(strlen(pkgName) + 1));
strcpy(pkgPtr->packageName, pkgName);
pkgPtr->loadHandle = NULL;
pkgPtr->initProc = initProc;
pkgPtr->safeInitProc = safeInitProc;
Tcl_MutexLock(&packageMutex);
pkgPtr->nextPtr = firstPackagePtr;
firstPackagePtr = pkgPtr;
Tcl_MutexUnlock(&packageMutex);
if (interp != NULL) {
ipFirstPtr = (InterpPackage *) Tcl_GetAssocData(interp, "tclLoad",
(Tcl_InterpDeleteProc **) NULL);
ipPtr = (InterpPackage *) ckalloc(sizeof(InterpPackage));
ipPtr->pkgPtr = pkgPtr;
ipPtr->nextPtr = ipFirstPtr;
Tcl_SetAssocData(interp, "tclLoad", LoadCleanupProc,
(ClientData) ipPtr);
}
}
/*
*----------------------------------------------------------------------
*
* TclGetLoadedPackages --
*
* This procedure returns information about all of the files
* that are loaded (either in a particular intepreter, or
* for all interpreters).
*
* Results:
* The return value is a standard Tcl completion code. If
* successful, a list of lists is placed in the interp's result.
* Each sublist corresponds to one loaded file; its first
* element is the name of the file (or an empty string for
* something that's statically loaded) and the second element
* is the name of the package in that file.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
int
TclGetLoadedPackages(interp, targetName)
Tcl_Interp *interp; /* Interpreter in which to return
* information or error message. */
char *targetName; /* Name of target interpreter or NULL.
* If NULL, return info about all interps;
* otherwise, just return info about this
* interpreter. */
{
Tcl_Interp *target;
LoadedPackage *pkgPtr;
InterpPackage *ipPtr;
char *prefix;
if (targetName == NULL) {
/*
* Return information about all of the available packages.
*/
prefix = "{";
Tcl_MutexLock(&packageMutex);
for (pkgPtr = firstPackagePtr; pkgPtr != NULL;
pkgPtr = pkgPtr->nextPtr) {
Tcl_AppendResult(interp, prefix, (char *) NULL);
Tcl_AppendElement(interp, pkgPtr->fileName);
Tcl_AppendElement(interp, pkgPtr->packageName);
Tcl_AppendResult(interp, "}", (char *) NULL);
prefix = " {";
}
Tcl_MutexUnlock(&packageMutex);
return TCL_OK;
}
/*
* Return information about only the packages that are loaded in
* a given interpreter.
*/
target = Tcl_GetSlave(interp, targetName);
if (target == NULL) {
return TCL_ERROR;
}
ipPtr = (InterpPackage *) Tcl_GetAssocData(target, "tclLoad",
(Tcl_InterpDeleteProc **) NULL);
prefix = "{";
for ( ; ipPtr != NULL; ipPtr = ipPtr->nextPtr) {
pkgPtr = ipPtr->pkgPtr;
Tcl_AppendResult(interp, prefix, (char *) NULL);
Tcl_AppendElement(interp, pkgPtr->fileName);
Tcl_AppendElement(interp, pkgPtr->packageName);
Tcl_AppendResult(interp, "}", (char *) NULL);
prefix = " {";
}
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* LoadCleanupProc --
*
* This procedure is called to delete all of the InterpPackage
* structures for an interpreter when the interpreter is deleted.
* It gets invoked via the Tcl AssocData mechanism.
*
* Results:
* None.
*
* Side effects:
* Storage for all of the InterpPackage procedures for interp
* get deleted.
*
*----------------------------------------------------------------------
*/
static void
LoadCleanupProc(clientData, interp)
ClientData clientData; /* Pointer to first InterpPackage structure
* for interp. */
Tcl_Interp *interp; /* Interpreter that is being deleted. */
{
InterpPackage *ipPtr, *nextPtr;
ipPtr = (InterpPackage *) clientData;
while (ipPtr != NULL) {
nextPtr = ipPtr->nextPtr;
ckfree((char *) ipPtr);
ipPtr = nextPtr;
}
}
/*
*----------------------------------------------------------------------
*
* TclFinalizeLoad --
*
* This procedure is invoked just before the application exits.
* It frees all of the LoadedPackage structures.
*
* Results:
* None.
*
* Side effects:
* Memory is freed.
*
*----------------------------------------------------------------------
*/
void
TclFinalizeLoad()
{
LoadedPackage *pkgPtr;
/*
* No synchronization here because there should just be
* one thread alive at this point. Logically,
* packageMutex should be grabbed at this point, but
* the Mutexes get finalized before the call to this routine.
* The only subsystem left alive at this point is the
* memory allocator.
*/
while (firstPackagePtr != NULL) {
pkgPtr = firstPackagePtr;
firstPackagePtr = pkgPtr->nextPtr;
#if defined(TCL_UNLOAD_DLLS) || defined(__WIN32__)
/*
* Some Unix dlls are poorly behaved - registering things like
* atexit calls that can't be unregistered. If you unload
* such dlls, you get a core on exit because it wants to
* call a function in the dll after it's been unloaded.
*/
if (pkgPtr->fileName[0] != '\0') {
Tcl_FSUnloadFileProc *unLoadProcPtr = pkgPtr->unLoadProcPtr;
if (unLoadProcPtr != NULL) {
(*unLoadProcPtr)(pkgPtr->loadHandle);
}
}
#endif
ckfree(pkgPtr->fileName);
ckfree(pkgPtr->packageName);
ckfree((char *) pkgPtr);
}
}
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