/*
* tclTrace.c --
*
* This file contains code to handle most trace management.
*
* Copyright (c) 1987-1993 The Regents of the University of California.
* Copyright (c) 1994-1997 Sun Microsystems, Inc.
* Copyright (c) 1998-2000 Scriptics Corporation.
* Copyright (c) 2002 ActiveState Corporation.
*
* See the file "license.terms" for information on usage and redistribution of
* this file, and for a DISCLAIMER OF ALL WARRANTIES.
*
* RCS: @(#) $Id: tclTrace.c,v 1.47.2.3 2010/08/19 10:04:15 dkf Exp $
*/
#include "tclInt.h"
/*
* Structures used to hold information about variable traces:
*/
typedef struct {
int flags; /* Operations for which Tcl command is to be
* invoked. */
size_t length; /* Number of non-NUL chars. in command. */
char command[4]; /* Space for Tcl command to invoke. Actual
* size will be as large as necessary to hold
* command. This field must be the last in the
* structure, so that it can be larger than 4
* bytes. */
} TraceVarInfo;
typedef struct {
VarTrace traceInfo;
TraceVarInfo traceCmdInfo;
} CombinedTraceVarInfo;
/*
* Structure used to hold information about command traces:
*/
typedef struct {
int flags; /* Operations for which Tcl command is to be
* invoked. */
size_t length; /* Number of non-NUL chars. in command. */
Tcl_Trace stepTrace; /* Used for execution traces, when tracing
* inside the given command */
int startLevel; /* Used for bookkeeping with step execution
* traces, store the level at which the step
* trace was invoked */
char *startCmd; /* Used for bookkeeping with step execution
* traces, store the command name which
* invoked step trace */
int curFlags; /* Trace flags for the current command */
int curCode; /* Return code for the current command */
int refCount; /* Used to ensure this structure is not
* deleted too early. Keeps track of how many
* pieces of code have a pointer to this
* structure. */
char command[4]; /* Space for Tcl command to invoke. Actual
* size will be as large as necessary to hold
* command. This field must be the last in the
* structure, so that it can be larger than 4
* bytes. */
} TraceCommandInfo;
/*
* Used by command execution traces. Note that we assume in the code that
* TCL_TRACE_ENTER_DURING_EXEC == 4 * TCL_TRACE_ENTER_EXEC and that
* TCL_TRACE_LEAVE_DURING_EXEC == 4 * TCL_TRACE_LEAVE_EXEC.
*
* TCL_TRACE_ENTER_DURING_EXEC - Trace each command inside the command
* currently being traced, before execution.
* TCL_TRACE_LEAVE_DURING_EXEC - Trace each command inside the command
* currently being traced, after execution.
* TCL_TRACE_ANY_EXEC - OR'd combination of all EXEC flags.
* TCL_TRACE_EXEC_IN_PROGRESS - The callback function on this trace is
* currently executing. Therefore we don't let
* further traces execute.
* TCL_TRACE_EXEC_DIRECT - This execution trace is triggered directly
* by the command being traced, not because of
* an internal trace.
* The flags 'TCL_TRACE_DESTROYED' and 'TCL_INTERP_DESTROYED' may also be used
* in command execution traces.
*/
#define TCL_TRACE_ENTER_DURING_EXEC 4
#define TCL_TRACE_LEAVE_DURING_EXEC 8
#define TCL_TRACE_ANY_EXEC 15
#define TCL_TRACE_EXEC_IN_PROGRESS 0x10
#define TCL_TRACE_EXEC_DIRECT 0x20
/*
* Forward declarations for functions defined in this file:
*/
typedef int (Tcl_TraceTypeObjCmd)(Tcl_Interp *interp, int optionIndex,
int objc, Tcl_Obj *const objv[]);
static Tcl_TraceTypeObjCmd TraceVariableObjCmd;
static Tcl_TraceTypeObjCmd TraceCommandObjCmd;
static Tcl_TraceTypeObjCmd TraceExecutionObjCmd;
/*
* Each subcommand has a number of 'types' to which it can apply. Currently
* 'execution', 'command' and 'variable' are the only types supported. These
* three arrays MUST be kept in sync! In the future we may provide an API to
* add to the list of supported trace types.
*/
static const char *traceTypeOptions[] = {
"execution", "command", "variable", NULL
};
static Tcl_TraceTypeObjCmd *traceSubCmds[] = {
TraceExecutionObjCmd,
TraceCommandObjCmd,
TraceVariableObjCmd,
};
/*
* Declarations for local functions to this file:
*/
static int CallTraceFunction(Tcl_Interp *interp, Trace *tracePtr,
Command *cmdPtr, const char *command, int numChars,
int objc, Tcl_Obj *const objv[]);
static char * TraceVarProc(ClientData clientData, Tcl_Interp *interp,
const char *name1, const char *name2, int flags);
static void TraceCommandProc(ClientData clientData,
Tcl_Interp *interp, const char *oldName,
const char *newName, int flags);
static Tcl_CmdObjTraceProc TraceExecutionProc;
static int StringTraceProc(ClientData clientData,
Tcl_Interp *interp, int level,
const char *command, Tcl_Command commandInfo,
int objc, Tcl_Obj *const objv[]);
static void StringTraceDeleteProc(ClientData clientData);
static void DisposeTraceResult(int flags, char *result);
static int TraceVarEx(Tcl_Interp *interp, const char *part1,
const char *part2, register VarTrace *tracePtr);
/*
* The following structure holds the client data for string-based
* trace procs
*/
typedef struct StringTraceData {
ClientData clientData; /* Client data from Tcl_CreateTrace */
Tcl_CmdTraceProc *proc; /* Trace function from Tcl_CreateTrace */
} StringTraceData;
/*
*----------------------------------------------------------------------
*
* Tcl_TraceObjCmd --
*
* This function is invoked to process the "trace" Tcl command. See the
* user documentation for details on what it does.
*
* Standard syntax as of Tcl 8.4 is:
* trace {add|info|remove} {command|variable} name ops cmd
*
* Results:
* A standard Tcl result.
*
* Side effects:
* See the user documentation.
*----------------------------------------------------------------------
*/
/* ARGSUSED */
int
Tcl_TraceObjCmd(
ClientData dummy, /* Not used. */
Tcl_Interp *interp, /* Current interpreter. */
int objc, /* Number of arguments. */
Tcl_Obj *const objv[]) /* Argument objects. */
{
int optionIndex;
char *name, *flagOps, *p;
/* Main sub commands to 'trace' */
static const char *traceOptions[] = {
"add", "info", "remove",
#ifndef TCL_REMOVE_OBSOLETE_TRACES
"variable", "vdelete", "vinfo",
#endif
NULL
};
/* 'OLD' options are pre-Tcl-8.4 style */
enum traceOptions {
TRACE_ADD, TRACE_INFO, TRACE_REMOVE,
#ifndef TCL_REMOVE_OBSOLETE_TRACES
TRACE_OLD_VARIABLE, TRACE_OLD_VDELETE, TRACE_OLD_VINFO
#endif
};
if (objc < 2) {
Tcl_WrongNumArgs(interp, 1, objv, "option ?arg arg ...?");
return TCL_ERROR;
}
if (Tcl_GetIndexFromObj(interp, objv[1], traceOptions,
"option", 0, &optionIndex) != TCL_OK) {
return TCL_ERROR;
}
switch ((enum traceOptions) optionIndex) {
case TRACE_ADD:
case TRACE_REMOVE: {
/*
* All sub commands of trace add/remove must take at least one more
* argument. Beyond that we let the subcommand itself control the
* argument structure.
*/
int typeIndex;
if (objc < 3) {
Tcl_WrongNumArgs(interp, 2, objv, "type ?arg arg ...?");
return TCL_ERROR;
}
if (Tcl_GetIndexFromObj(interp, objv[2], traceTypeOptions, "option",
0, &typeIndex) != TCL_OK) {
return TCL_ERROR;
}
return (traceSubCmds[typeIndex])(interp, optionIndex, objc, objv);
}
case TRACE_INFO: {
/*
* All sub commands of trace info must take exactly two more arguments
* which name the type of thing being traced and the name of the thing
* being traced.
*/
int typeIndex;
if (objc < 3) {
/*
* Delegate other complaints to the type-specific code which can
* give a better error message.
*/
Tcl_WrongNumArgs(interp, 2, objv, "type name");
return TCL_ERROR;
}
if (Tcl_GetIndexFromObj(interp, objv[2], traceTypeOptions, "option",
0, &typeIndex) != TCL_OK) {
return TCL_ERROR;
}
return (traceSubCmds[typeIndex])(interp, optionIndex, objc, objv);
break;
}
#ifndef TCL_REMOVE_OBSOLETE_TRACES
case TRACE_OLD_VARIABLE:
case TRACE_OLD_VDELETE: {
Tcl_Obj *copyObjv[6];
Tcl_Obj *opsList;
int code, numFlags;
if (objc != 5) {
Tcl_WrongNumArgs(interp, 2, objv, "name ops command");
return TCL_ERROR;
}
opsList = Tcl_NewObj();
Tcl_IncrRefCount(opsList);
flagOps = Tcl_GetStringFromObj(objv[3], &numFlags);
if (numFlags == 0) {
Tcl_DecrRefCount(opsList);
goto badVarOps;
}
for (p = flagOps; *p != 0; p++) {
Tcl_Obj *opObj;
if (*p == 'r') {
TclNewLiteralStringObj(opObj, "read");
} else if (*p == 'w') {
TclNewLiteralStringObj(opObj, "write");
} else if (*p == 'u') {
TclNewLiteralStringObj(opObj, "unset");
} else if (*p == 'a') {
TclNewLiteralStringObj(opObj, "array");
} else {
Tcl_DecrRefCount(opsList);
goto badVarOps;
}
Tcl_ListObjAppendElement(NULL, opsList, opObj);
}
copyObjv[0] = NULL;
memcpy(copyObjv+1, objv, objc*sizeof(Tcl_Obj *));
copyObjv[4] = opsList;
if (optionIndex == TRACE_OLD_VARIABLE) {
code = (traceSubCmds[2])(interp, TRACE_ADD, objc+1, copyObjv);
} else {
code = (traceSubCmds[2])(interp, TRACE_REMOVE, objc+1, copyObjv);
}
Tcl_DecrRefCount(opsList);
return code;
}
case TRACE_OLD_VINFO: {
ClientData clientData;
char ops[5];
Tcl_Obj *resultListPtr, *pairObjPtr, *elemObjPtr;
if (objc != 3) {
Tcl_WrongNumArgs(interp, 2, objv, "name");
return TCL_ERROR;
}
resultListPtr = Tcl_NewObj();
clientData = 0;
name = Tcl_GetString(objv[2]);
while ((clientData = Tcl_VarTraceInfo(interp, name, 0,
TraceVarProc, clientData)) != 0) {
TraceVarInfo *tvarPtr = (TraceVarInfo *) clientData;
pairObjPtr = Tcl_NewListObj(0, NULL);
p = ops;
if (tvarPtr->flags & TCL_TRACE_READS) {
*p = 'r';
p++;
}
if (tvarPtr->flags & TCL_TRACE_WRITES) {
*p = 'w';
p++;
}
if (tvarPtr->flags & TCL_TRACE_UNSETS) {
*p = 'u';
p++;
}
if (tvarPtr->flags & TCL_TRACE_ARRAY) {
*p = 'a';
p++;
}
*p = '\0';
/*
* Build a pair (2-item list) with the ops string as the first obj
* element and the tvarPtr->command string as the second obj
* element. Append the pair (as an element) to the end of the
* result object list.
*/
elemObjPtr = Tcl_NewStringObj(ops, -1);
Tcl_ListObjAppendElement(NULL, pairObjPtr, elemObjPtr);
elemObjPtr = Tcl_NewStringObj(tvarPtr->command, -1);
Tcl_ListObjAppendElement(NULL, pairObjPtr, elemObjPtr);
Tcl_ListObjAppendElement(interp, resultListPtr, pairObjPtr);
}
Tcl_SetObjResult(interp, resultListPtr);
break;
}
#endif /* TCL_REMOVE_OBSOLETE_TRACES */
}
return TCL_OK;
badVarOps:
Tcl_AppendResult(interp, "bad operations \"", flagOps,
"\": should be one or more of rwua", NULL);
return TCL_ERROR;
}
/*
*----------------------------------------------------------------------
*
* TraceExecutionObjCmd --
*
* Helper function for Tcl_TraceObjCmd; implements the [trace
* {add|remove|info} execution ...] subcommands. See the user
* documentation for details on what these do.
*
* Results:
* Standard Tcl result.
*
* Side effects:
* Depends on the operation (add, remove, or info) being performed; may
* add or remove command traces on a command.
*
*----------------------------------------------------------------------
*/
static int
TraceExecutionObjCmd(
Tcl_Interp *interp, /* Current interpreter. */
int optionIndex, /* Add, info or remove */
int objc, /* Number of arguments. */
Tcl_Obj *const objv[]) /* Argument objects. */
{
int commandLength, index;
char *name, *command;
size_t length;
enum traceOptions {
TRACE_ADD, TRACE_INFO, TRACE_REMOVE
};
static const char *opStrings[] = {
"enter", "leave", "enterstep", "leavestep", NULL
};
enum operations {
TRACE_EXEC_ENTER, TRACE_EXEC_LEAVE,
TRACE_EXEC_ENTER_STEP, TRACE_EXEC_LEAVE_STEP
};
switch ((enum traceOptions) optionIndex) {
case TRACE_ADD:
case TRACE_REMOVE: {
int flags = 0;
int i, listLen, result;
Tcl_Obj **elemPtrs;
if (objc != 6) {
Tcl_WrongNumArgs(interp, 3, objv, "name opList command");
return TCL_ERROR;
}
/*
* Make sure the ops argument is a list object; get its length and a
* pointer to its array of element pointers.
*/
result = Tcl_ListObjGetElements(interp, objv[4], &listLen, &elemPtrs);
if (result != TCL_OK) {
return result;
}
if (listLen == 0) {
Tcl_SetResult(interp, "bad operation list \"\": must be "
"one or more of enter, leave, enterstep, or leavestep",
TCL_STATIC);
return TCL_ERROR;
}
for (i = 0; i < listLen; i++) {
if (Tcl_GetIndexFromObj(interp, elemPtrs[i], opStrings,
"operation", TCL_EXACT, &index) != TCL_OK) {
return TCL_ERROR;
}
switch ((enum operations) index) {
case TRACE_EXEC_ENTER:
flags |= TCL_TRACE_ENTER_EXEC;
break;
case TRACE_EXEC_LEAVE:
flags |= TCL_TRACE_LEAVE_EXEC;
break;
case TRACE_EXEC_ENTER_STEP:
flags |= TCL_TRACE_ENTER_DURING_EXEC;
break;
case TRACE_EXEC_LEAVE_STEP:
flags |= TCL_TRACE_LEAVE_DURING_EXEC;
break;
}
}
command = Tcl_GetStringFromObj(objv[5], &commandLength);
length = (size_t) commandLength;
if ((enum traceOptions) optionIndex == TRACE_ADD) {
TraceCommandInfo *tcmdPtr;
tcmdPtr = (TraceCommandInfo *) ckalloc((unsigned)
(sizeof(TraceCommandInfo) - sizeof(tcmdPtr->command)
+ length + 1));
tcmdPtr->flags = flags;
tcmdPtr->stepTrace = NULL;
tcmdPtr->startLevel = 0;
tcmdPtr->startCmd = NULL;
tcmdPtr->length = length;
tcmdPtr->refCount = 1;
flags |= TCL_TRACE_DELETE;
if (flags & (TCL_TRACE_ENTER_DURING_EXEC |
TCL_TRACE_LEAVE_DURING_EXEC)) {
flags |= (TCL_TRACE_ENTER_EXEC | TCL_TRACE_LEAVE_EXEC);
}
memcpy(tcmdPtr->command, command, length+1);
name = Tcl_GetString(objv[3]);
if (Tcl_TraceCommand(interp, name, flags, TraceCommandProc,
(ClientData) tcmdPtr) != TCL_OK) {
ckfree((char *) tcmdPtr);
return TCL_ERROR;
}
} else {
/*
* Search through all of our traces on this command to see if
* there's one with the given command. If so, then delete the
* first one that matches.
*/
TraceCommandInfo *tcmdPtr;
ClientData clientData = NULL;
name = Tcl_GetString(objv[3]);
/*
* First ensure the name given is valid.
*/
if (Tcl_FindCommand(interp,name,NULL,TCL_LEAVE_ERR_MSG) == NULL) {
return TCL_ERROR;
}
while ((clientData = Tcl_CommandTraceInfo(interp, name, 0,
TraceCommandProc, clientData)) != NULL) {
tcmdPtr = (TraceCommandInfo *) clientData;
/*
* In checking the 'flags' field we must remove any extraneous
* flags which may have been temporarily added by various
* pieces of the trace mechanism.
*/
if ((tcmdPtr->length == length)
&& ((tcmdPtr->flags & (TCL_TRACE_ANY_EXEC |
TCL_TRACE_RENAME | TCL_TRACE_DELETE)) == flags)
&& (strncmp(command, tcmdPtr->command,
(size_t) length) == 0)) {
flags |= TCL_TRACE_DELETE;
if (flags & (TCL_TRACE_ENTER_DURING_EXEC |
TCL_TRACE_LEAVE_DURING_EXEC)) {
flags |= (TCL_TRACE_ENTER_EXEC | TCL_TRACE_LEAVE_EXEC);
}
Tcl_UntraceCommand(interp, name, flags,
TraceCommandProc, clientData);
if (tcmdPtr->stepTrace != NULL) {
/*
* We need to remove the interpreter-wide trace which
* we created to allow 'step' traces.
*/
Tcl_DeleteTrace(interp, tcmdPtr->stepTrace);
tcmdPtr->stepTrace = NULL;
if (tcmdPtr->startCmd != NULL) {
ckfree((char *) tcmdPtr->startCmd);
}
}
if (tcmdPtr->flags & TCL_TRACE_EXEC_IN_PROGRESS) {
/*
* Postpone deletion.
*/
tcmdPtr->flags = 0;
}
if ((--tcmdPtr->refCount) <= 0) {
ckfree((char *) tcmdPtr);
}
break;
}
}
}
break;
}
case TRACE_INFO: {
ClientData clientData;
Tcl_Obj *resultListPtr, *eachTraceObjPtr, *elemObjPtr;
if (objc != 4) {
Tcl_WrongNumArgs(interp, 3, objv, "name");
return TCL_ERROR;
}
clientData = NULL;
name = Tcl_GetString(objv[3]);
/*
* First ensure the name given is valid.
*/
if (Tcl_FindCommand(interp, name, NULL, TCL_LEAVE_ERR_MSG) == NULL) {
return TCL_ERROR;
}
resultListPtr = Tcl_NewListObj(0, NULL);
while ((clientData = Tcl_CommandTraceInfo(interp, name, 0,
TraceCommandProc, clientData)) != NULL) {
int numOps = 0;
Tcl_Obj *opObj;
TraceCommandInfo *tcmdPtr = (TraceCommandInfo *) clientData;
/*
* Build a list with the ops list as the first obj element and the
* tcmdPtr->command string as the second obj element. Append this
* list (as an element) to the end of the result object list.
*/
elemObjPtr = Tcl_NewListObj(0, NULL);
Tcl_IncrRefCount(elemObjPtr);
if (tcmdPtr->flags & TCL_TRACE_ENTER_EXEC) {
TclNewLiteralStringObj(opObj, "enter");
Tcl_ListObjAppendElement(NULL, elemObjPtr, opObj);
}
if (tcmdPtr->flags & TCL_TRACE_LEAVE_EXEC) {
TclNewLiteralStringObj(opObj, "leave");
Tcl_ListObjAppendElement(NULL, elemObjPtr, opObj);
}
if (tcmdPtr->flags & TCL_TRACE_ENTER_DURING_EXEC) {
TclNewLiteralStringObj(opObj, "enterstep");
Tcl_ListObjAppendElement(NULL, elemObjPtr, opObj);
}
if (tcmdPtr->flags & TCL_TRACE_LEAVE_DURING_EXEC) {
TclNewLiteralStringObj(opObj, "leavestep");
Tcl_ListObjAppendElement(NULL, elemObjPtr, opObj);
}
Tcl_ListObjLength(NULL, elemObjPtr, &numOps);
if (0 == numOps) {
Tcl_DecrRefCount(elemObjPtr);
continue;
}
eachTraceObjPtr = Tcl_NewListObj(0, NULL);
Tcl_ListObjAppendElement(NULL, eachTraceObjPtr, elemObjPtr);
Tcl_DecrRefCount(elemObjPtr);
elemObjPtr = NULL;
Tcl_ListObjAppendElement(NULL, eachTraceObjPtr,
Tcl_NewStringObj(tcmdPtr->command, -1));
Tcl_ListObjAppendElement(interp, resultListPtr, eachTraceObjPtr);
}
Tcl_SetObjResult(interp, resultListPtr);
break;
}
}
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* TraceCommandObjCmd --
*
* Helper function for Tcl_TraceObjCmd; implements the [trace
* {add|info|remove} command ...] subcommands. See the user documentation
* for details on what these do.
*
* Results:
* Standard Tcl result.
*
* Side effects:
* Depends on the operation (add, remove, or info) being performed; may
* add or remove command traces on a command.
*
*----------------------------------------------------------------------
*/
static int
TraceCommandObjCmd(
Tcl_Interp *interp, /* Current interpreter. */
int optionIndex, /* Add, info or remove */
int objc, /* Number of arguments. */
Tcl_Obj *const objv[]) /* Argument objects. */
{
int commandLength, index;
char *name, *command;
size_t length;
enum traceOptions { TRACE_ADD, TRACE_INFO, TRACE_REMOVE };
static const char *opStrings[] = { "delete", "rename", NULL };
enum operations { TRACE_CMD_DELETE, TRACE_CMD_RENAME };
switch ((enum traceOptions) optionIndex) {
case TRACE_ADD:
case TRACE_REMOVE: {
int flags = 0;
int i, listLen, result;
Tcl_Obj **elemPtrs;
if (objc != 6) {
Tcl_WrongNumArgs(interp, 3, objv, "name opList command");
return TCL_ERROR;
}
/*
* Make sure the ops argument is a list object; get its length and a
* pointer to its array of element pointers.
*/
result = Tcl_ListObjGetElements(interp, objv[4], &listLen, &elemPtrs);
if (result != TCL_OK) {
return result;
}
if (listLen == 0) {
Tcl_SetResult(interp, "bad operation list \"\": must be "
"one or more of delete or rename", TCL_STATIC);
return TCL_ERROR;
}
for (i = 0; i < listLen; i++) {
if (Tcl_GetIndexFromObj(interp, elemPtrs[i], opStrings,
"operation", TCL_EXACT, &index) != TCL_OK) {
return TCL_ERROR;
}
switch ((enum operations) index) {
case TRACE_CMD_RENAME:
flags |= TCL_TRACE_RENAME;
break;
case TRACE_CMD_DELETE:
flags |= TCL_TRACE_DELETE;
break;
}
}
command = Tcl_GetStringFromObj(objv[5], &commandLength);
length = (size_t) commandLength;
if ((enum traceOptions) optionIndex == TRACE_ADD) {
TraceCommandInfo *tcmdPtr;
tcmdPtr = (TraceCommandInfo *) ckalloc((unsigned)
(sizeof(TraceCommandInfo) - sizeof(tcmdPtr->command)
+ length + 1));
tcmdPtr->flags = flags;
tcmdPtr->stepTrace = NULL;
tcmdPtr->startLevel = 0;
tcmdPtr->startCmd = NULL;
tcmdPtr->length = length;
tcmdPtr->refCount = 1;
flags |= TCL_TRACE_DELETE;
memcpy(tcmdPtr->command, command, length+1);
name = Tcl_GetString(objv[3]);
if (Tcl_TraceCommand(interp, name, flags, TraceCommandProc,
(ClientData) tcmdPtr) != TCL_OK) {
ckfree((char *) tcmdPtr);
return TCL_ERROR;
}
} else {
/*
* Search through all of our traces on this command to see if
* there's one with the given command. If so, then delete the
* first one that matches.
*/
TraceCommandInfo *tcmdPtr;
ClientData clientData = NULL;
name = Tcl_GetString(objv[3]);
/*
* First ensure the name given is valid.
*/
if (Tcl_FindCommand(interp,name,NULL,TCL_LEAVE_ERR_MSG) == NULL) {
return TCL_ERROR;
}
while ((clientData = Tcl_CommandTraceInfo(interp, name, 0,
TraceCommandProc, clientData)) != NULL) {
tcmdPtr = (TraceCommandInfo *) clientData;
if ((tcmdPtr->length == length)
&& (tcmdPtr->flags == flags)
&& (strncmp(command, tcmdPtr->command,
(size_t) length) == 0)) {
Tcl_UntraceCommand(interp, name, flags | TCL_TRACE_DELETE,
TraceCommandProc, clientData);
tcmdPtr->flags |= TCL_TRACE_DESTROYED;
if ((--tcmdPtr->refCount) <= 0) {
ckfree((char *) tcmdPtr);
}
break;
}
}
}
break;
}
case TRACE_INFO: {
ClientData clientData;
Tcl_Obj *resultListPtr, *eachTraceObjPtr, *elemObjPtr;
if (objc != 4) {
Tcl_WrongNumArgs(interp, 3, objv, "name");
return TCL_ERROR;
}
clientData = NULL;
name = Tcl_GetString(objv[3]);
/*
* First ensure the name given is valid.
*/
if (Tcl_FindCommand(interp, name, NULL, TCL_LEAVE_ERR_MSG) == NULL) {
return TCL_ERROR;
}
resultListPtr = Tcl_NewListObj(0, NULL);
while ((clientData = Tcl_CommandTraceInfo(interp, name, 0,
TraceCommandProc, clientData)) != NULL) {
int numOps = 0;
Tcl_Obj *opObj;
TraceCommandInfo *tcmdPtr = (TraceCommandInfo *) clientData;
/*
* Build a list with the ops list as the first obj element and the
* tcmdPtr->command string as the second obj element. Append this
* list (as an element) to the end of the result object list.
*/
elemObjPtr = Tcl_NewListObj(0, NULL);
Tcl_IncrRefCount(elemObjPtr);
if (tcmdPtr->flags & TCL_TRACE_RENAME) {
TclNewLiteralStringObj(opObj, "rename");
Tcl_ListObjAppendElement(NULL, elemObjPtr, opObj);
}
if (tcmdPtr->flags & TCL_TRACE_DELETE) {
TclNewLiteralStringObj(opObj, "delete");
Tcl_ListObjAppendElement(NULL, elemObjPtr, opObj);
}
Tcl_ListObjLength(NULL, elemObjPtr, &numOps);
if (0 == numOps) {
Tcl_DecrRefCount(elemObjPtr);
continue;
}
eachTraceObjPtr = Tcl_NewListObj(0, NULL);
Tcl_ListObjAppendElement(NULL, eachTraceObjPtr, elemObjPtr);
Tcl_DecrRefCount(elemObjPtr);
elemObjPtr = Tcl_NewStringObj(tcmdPtr->command, -1);
Tcl_ListObjAppendElement(NULL, eachTraceObjPtr, elemObjPtr);
Tcl_ListObjAppendElement(interp, resultListPtr, eachTraceObjPtr);
}
Tcl_SetObjResult(interp, resultListPtr);
break;
}
}
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* TraceVariableObjCmd --
*
* Helper function for Tcl_TraceObjCmd; implements the [trace
* {add|info|remove} variable ...] subcommands. See the user
* documentation for details on what these do.
*
* Results:
* Standard Tcl result.
*
* Side effects:
* Depends on the operation (add, remove, or info) being performed; may
* add or remove variable traces on a variable.
*
*----------------------------------------------------------------------
*/
static int
TraceVariableObjCmd(
Tcl_Interp *interp, /* Current interpreter. */
int optionIndex, /* Add, info or remove */
int objc, /* Number of arguments. */
Tcl_Obj *const objv[]) /* Argument objects. */
{
int commandLength, index;
char *name, *command;
size_t length;
enum traceOptions { TRACE_ADD, TRACE_INFO, TRACE_REMOVE };
static const char *opStrings[] = {
"array", "read", "unset", "write", NULL
};
enum operations {
TRACE_VAR_ARRAY, TRACE_VAR_READ, TRACE_VAR_UNSET, TRACE_VAR_WRITE
};
switch ((enum traceOptions) optionIndex) {
case TRACE_ADD:
case TRACE_REMOVE: {
int flags = 0;
int i, listLen, result;
Tcl_Obj **elemPtrs;
if (objc != 6) {
Tcl_WrongNumArgs(interp, 3, objv, "name opList command");
return TCL_ERROR;
}
/*
* Make sure the ops argument is a list object; get its length and a
* pointer to its array of element pointers.
*/
result = Tcl_ListObjGetElements(interp, objv[4], &listLen, &elemPtrs);
if (result != TCL_OK) {
return result;
}
if (listLen == 0) {
Tcl_SetResult(interp, "bad operation list \"\": must be "
"one or more of array, read, unset, or write", TCL_STATIC);
return TCL_ERROR;
}
for (i = 0; i < listLen ; i++) {
if (Tcl_GetIndexFromObj(interp, elemPtrs[i], opStrings,
"operation", TCL_EXACT, &index) != TCL_OK) {
return TCL_ERROR;
}
switch ((enum operations) index) {
case TRACE_VAR_ARRAY:
flags |= TCL_TRACE_ARRAY;
break;
case TRACE_VAR_READ:
flags |= TCL_TRACE_READS;
break;
case TRACE_VAR_UNSET:
flags |= TCL_TRACE_UNSETS;
break;
case TRACE_VAR_WRITE:
flags |= TCL_TRACE_WRITES;
break;
}
}
command = Tcl_GetStringFromObj(objv[5], &commandLength);
length = (size_t) commandLength;
if ((enum traceOptions) optionIndex == TRACE_ADD) {
CombinedTraceVarInfo *ctvarPtr;
ctvarPtr = (CombinedTraceVarInfo *) ckalloc((unsigned)
(sizeof(CombinedTraceVarInfo) + length + 1
- sizeof(ctvarPtr->traceCmdInfo.command)));
ctvarPtr->traceCmdInfo.flags = flags;
if (objv[0] == NULL) {
ctvarPtr->traceCmdInfo.flags |= TCL_TRACE_OLD_STYLE;
}
ctvarPtr->traceCmdInfo.length = length;
flags |= TCL_TRACE_UNSETS | TCL_TRACE_RESULT_OBJECT;
memcpy(ctvarPtr->traceCmdInfo.command, command, length+1);
ctvarPtr->traceInfo.traceProc = TraceVarProc;
ctvarPtr->traceInfo.clientData = (ClientData)
&ctvarPtr->traceCmdInfo;
ctvarPtr->traceInfo.flags = flags;
name = Tcl_GetString(objv[3]);
if (TraceVarEx(interp,name,NULL,(VarTrace*)ctvarPtr) != TCL_OK) {
ckfree((char *) ctvarPtr);
return TCL_ERROR;
}
} else {
/*
* Search through all of our traces on this variable to see if
* there's one with the given command. If so, then delete the
* first one that matches.
*/
TraceVarInfo *tvarPtr;
ClientData clientData = 0;
name = Tcl_GetString(objv[3]);
while ((clientData = Tcl_VarTraceInfo(interp, name, 0,
TraceVarProc, clientData)) != 0) {
tvarPtr = (TraceVarInfo *) clientData;
if ((tvarPtr->length == length)
&& ((tvarPtr->flags & ~TCL_TRACE_OLD_STYLE)==flags)
&& (strncmp(command, tvarPtr->command,
(size_t) length) == 0)) {
Tcl_UntraceVar2(interp, name, NULL,
flags | TCL_TRACE_UNSETS | TCL_TRACE_RESULT_OBJECT,
TraceVarProc, clientData);
break;
}
}
}
break;
}
case TRACE_INFO: {
ClientData clientData;
Tcl_Obj *resultListPtr, *eachTraceObjPtr, *elemObjPtr;
if (objc != 4) {
Tcl_WrongNumArgs(interp, 3, objv, "name");
return TCL_ERROR;
}
resultListPtr = Tcl_NewObj();
clientData = 0;
name = Tcl_GetString(objv[3]);
while ((clientData = Tcl_VarTraceInfo(interp, name, 0, TraceVarProc,
clientData)) != 0) {
Tcl_Obj *opObj;
TraceVarInfo *tvarPtr = (TraceVarInfo *) clientData;
/*
* Build a list with the ops list as the first obj element and the
* tcmdPtr->command string as the second obj element. Append this
* list (as an element) to the end of the result object list.
*/
elemObjPtr = Tcl_NewListObj(0, NULL);
if (tvarPtr->flags & TCL_TRACE_ARRAY) {
TclNewLiteralStringObj(opObj, "array");
Tcl_ListObjAppendElement(NULL, elemObjPtr, opObj);
}
if (tvarPtr->flags & TCL_TRACE_READS) {
TclNewLiteralStringObj(opObj, "read");
Tcl_ListObjAppendElement(NULL, elemObjPtr, opObj);
}
if (tvarPtr->flags & TCL_TRACE_WRITES) {
TclNewLiteralStringObj(opObj, "write");
Tcl_ListObjAppendElement(NULL, elemObjPtr, opObj);
}
if (tvarPtr->flags & TCL_TRACE_UNSETS) {
TclNewLiteralStringObj(opObj, "unset");
Tcl_ListObjAppendElement(NULL, elemObjPtr, opObj);
}
eachTraceObjPtr = Tcl_NewListObj(0, NULL);
Tcl_ListObjAppendElement(NULL, eachTraceObjPtr, elemObjPtr);
elemObjPtr = Tcl_NewStringObj(tvarPtr->command, -1);
Tcl_ListObjAppendElement(NULL, eachTraceObjPtr, elemObjPtr);
Tcl_ListObjAppendElement(interp, resultListPtr,
eachTraceObjPtr);
}
Tcl_SetObjResult(interp, resultListPtr);
break;
}
}
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* Tcl_CommandTraceInfo --
*
* Return the clientData value associated with a trace on a command.
* This function can also be used to step through all of the traces on a
* particular command that have the same trace function.
*
* Results:
* The return value is the clientData value associated with a trace on
* the given command. Information will only be returned for a trace with
* proc as trace function. If the clientData argument is NULL then the
* first such trace is returned; otherwise, the next relevant one after
* the one given by clientData will be returned. If the command doesn't
* exist then an error message is left in the interpreter and NULL is
* returned. Also, if there are no (more) traces for the given command,
* NULL is returned.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
ClientData
Tcl_CommandTraceInfo(
Tcl_Interp *interp, /* Interpreter containing command. */
const char *cmdName, /* Name of command. */
int flags, /* OR-ed combo or TCL_GLOBAL_ONLY,
* TCL_NAMESPACE_ONLY (can be 0). */
Tcl_CommandTraceProc *proc, /* Function assocated with trace. */
ClientData prevClientData) /* If non-NULL, gives last value returned by
* this function, so this call will return the
* next trace after that one. If NULL, this
* call will return the first trace. */
{
Command *cmdPtr;
register CommandTrace *tracePtr;
cmdPtr = (Command *) Tcl_FindCommand(interp, cmdName, NULL,
TCL_LEAVE_ERR_MSG);
if (cmdPtr == NULL) {
return NULL;
}
/*
* Find the relevant trace, if any, and return its clientData.
*/
tracePtr = cmdPtr->tracePtr;
if (prevClientData != NULL) {
for (; tracePtr!=NULL ; tracePtr=tracePtr->nextPtr) {
if ((tracePtr->clientData == prevClientData)
&& (tracePtr->traceProc == proc)) {
tracePtr = tracePtr->nextPtr;
break;
}
}
}
for (; tracePtr!=NULL ; tracePtr=tracePtr->nextPtr) {
if (tracePtr->traceProc == proc) {
return tracePtr->clientData;
}
}
return NULL;
}
/*
*----------------------------------------------------------------------
*
* Tcl_TraceCommand --
*
* Arrange for rename/deletes to a command to cause a function to be
* invoked, which can monitor the operations.
*
* Also optionally arrange for execution of that command to cause a
* function to be invoked.
*
* Results:
* A standard Tcl return value.
*
* Side effects:
* A trace is set up on the command given by cmdName, such that future
* changes to the command will be intermediated by proc. See the manual
* entry for complete details on the calling sequence for proc.
*
*----------------------------------------------------------------------
*/
int
Tcl_TraceCommand(
Tcl_Interp *interp, /* Interpreter in which command is to be
* traced. */
const char *cmdName, /* Name of command. */
int flags, /* OR-ed collection of bits, including any of
* TCL_TRACE_RENAME, TCL_TRACE_DELETE, and any
* of the TRACE_*_EXEC flags */
Tcl_CommandTraceProc *proc, /* Function to call when specified ops are
* invoked upon cmdName. */
ClientData clientData) /* Arbitrary argument to pass to proc. */
{
Command *cmdPtr;
register CommandTrace *tracePtr;
cmdPtr = (Command *) Tcl_FindCommand(interp, cmdName, NULL,
TCL_LEAVE_ERR_MSG);
if (cmdPtr == NULL) {
return TCL_ERROR;
}
/*
* Set up trace information.
*/
tracePtr = (CommandTrace *) ckalloc(sizeof(CommandTrace));
tracePtr->traceProc = proc;
tracePtr->clientData = clientData;
tracePtr->flags = flags &
(TCL_TRACE_RENAME | TCL_TRACE_DELETE | TCL_TRACE_ANY_EXEC);
tracePtr->nextPtr = cmdPtr->tracePtr;
tracePtr->refCount = 1;
cmdPtr->tracePtr = tracePtr;
if (tracePtr->flags & TCL_TRACE_ANY_EXEC) {
cmdPtr->flags |= CMD_HAS_EXEC_TRACES;
}
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* Tcl_UntraceCommand --
*
* Remove a previously-created trace for a command.
*
* Results:
* None.
*
* Side effects:
* If there exists a trace for the command given by cmdName with the
* given flags, proc, and clientData, then that trace is removed.
*
*----------------------------------------------------------------------
*/
void
Tcl_UntraceCommand(
Tcl_Interp *interp, /* Interpreter containing command. */
const char *cmdName, /* Name of command. */
int flags, /* OR-ed collection of bits, including any of
* TCL_TRACE_RENAME, TCL_TRACE_DELETE, and any
* of the TRACE_*_EXEC flags */
Tcl_CommandTraceProc *proc, /* Function assocated with trace. */
ClientData clientData) /* Arbitrary argument to pass to proc. */
{
register CommandTrace *tracePtr;
CommandTrace *prevPtr;
Command *cmdPtr;
Interp *iPtr = (Interp *) interp;
ActiveCommandTrace *activePtr;
int hasExecTraces = 0;
cmdPtr = (Command *) Tcl_FindCommand(interp, cmdName, NULL,
TCL_LEAVE_ERR_MSG);
if (cmdPtr == NULL) {
return;
}
flags &= (TCL_TRACE_RENAME | TCL_TRACE_DELETE | TCL_TRACE_ANY_EXEC);
for (tracePtr = cmdPtr->tracePtr, prevPtr = NULL; ;
prevPtr = tracePtr, tracePtr = tracePtr->nextPtr) {
if (tracePtr == NULL) {
return;
}
if ((tracePtr->traceProc == proc)
&& ((tracePtr->flags & (TCL_TRACE_RENAME | TCL_TRACE_DELETE |
TCL_TRACE_ANY_EXEC)) == flags)
&& (tracePtr->clientData == clientData)) {
if (tracePtr->flags & TCL_TRACE_ANY_EXEC) {
hasExecTraces = 1;
}
break;
}
}
/*
* The code below makes it possible to delete traces while traces are
* active: it makes sure that the deleted trace won't be processed by
* CallCommandTraces.
*/
for (activePtr = iPtr->activeCmdTracePtr; activePtr != NULL;
activePtr = activePtr->nextPtr) {
if (activePtr->nextTracePtr == tracePtr) {
if (activePtr->reverseScan) {
activePtr->nextTracePtr = prevPtr;
} else {
activePtr->nextTracePtr = tracePtr->nextPtr;
}
}
}
if (prevPtr == NULL) {
cmdPtr->tracePtr = tracePtr->nextPtr;
} else {
prevPtr->nextPtr = tracePtr->nextPtr;
}
tracePtr->flags = 0;
if ((--tracePtr->refCount) <= 0) {
ckfree((char *) tracePtr);
}
if (hasExecTraces) {
for (tracePtr = cmdPtr->tracePtr, prevPtr = NULL; tracePtr != NULL ;
prevPtr = tracePtr, tracePtr = tracePtr->nextPtr) {
if (tracePtr->flags & TCL_TRACE_ANY_EXEC) {
return;
}
}
/*
* None of the remaining traces on this command are execution traces.
* We therefore remove this flag:
*/
cmdPtr->flags &= ~CMD_HAS_EXEC_TRACES;
}
}
/*
*----------------------------------------------------------------------
*
* TraceCommandProc --
*
* This function is called to handle command changes that have been
* traced using the "trace" command, when using the 'rename' or 'delete'
* options.
*
* Results:
* None.
*
* Side effects:
* Depends on the command associated with the trace.
*
*----------------------------------------------------------------------
*/
/* ARGSUSED */
static void
TraceCommandProc(
ClientData clientData, /* Information about the command trace. */
Tcl_Interp *interp, /* Interpreter containing command. */
const char *oldName, /* Name of command being changed. */
const char *newName, /* New name of command. Empty string or NULL
* means command is being deleted (renamed to
* ""). */
int flags) /* OR-ed bits giving operation and other
* information. */
{
TraceCommandInfo *tcmdPtr = (TraceCommandInfo *) clientData;
int code;
Tcl_DString cmd;
tcmdPtr->refCount++;
if ((tcmdPtr->flags & flags) && !Tcl_InterpDeleted(interp)
&& !Tcl_LimitExceeded(interp)) {
/*
* Generate a command to execute by appending list elements for the
* old and new command name and the operation.
*/
Tcl_DStringInit(&cmd);
Tcl_DStringAppend(&cmd, tcmdPtr->command, (int) tcmdPtr->length);
Tcl_DStringAppendElement(&cmd, oldName);
Tcl_DStringAppendElement(&cmd, (newName ? newName : ""));
if (flags & TCL_TRACE_RENAME) {
Tcl_DStringAppend(&cmd, " rename", 7);
} else if (flags & TCL_TRACE_DELETE) {
Tcl_DStringAppend(&cmd, " delete", 7);
}
/*
* Execute the command. We discard any object result the command
* returns.
*
* Add the TCL_TRACE_DESTROYED flag to tcmdPtr to indicate to other
* areas that this will be destroyed by us, otherwise a double-free
* might occur depending on what the eval does.
*/
if (flags & TCL_TRACE_DESTROYED) {
tcmdPtr->flags |= TCL_TRACE_DESTROYED;
}
code = Tcl_EvalEx(interp, Tcl_DStringValue(&cmd),
Tcl_DStringLength(&cmd), 0);
if (code != TCL_OK) {
/* We ignore errors in these traced commands */
/*** QUESTION: Use Tcl_BackgroundError(interp); instead? ***/
}
Tcl_DStringFree(&cmd);
}
/*
* We delete when the trace was destroyed or if this is a delete trace,
* because command deletes are unconditional, so the trace must go away.
*/
if (flags & (TCL_TRACE_DESTROYED | TCL_TRACE_DELETE)) {
int untraceFlags = tcmdPtr->flags;
Tcl_InterpState state;
if (tcmdPtr->stepTrace != NULL) {
Tcl_DeleteTrace(interp, tcmdPtr->stepTrace);
tcmdPtr->stepTrace = NULL;
if (tcmdPtr->startCmd != NULL) {
ckfree((char *) tcmdPtr->startCmd);
}
}
if (tcmdPtr->flags & TCL_TRACE_EXEC_IN_PROGRESS) {
/*
* Postpone deletion, until exec trace returns.
*/
tcmdPtr->flags = 0;
}
/*
* We need to construct the same flags for Tcl_UntraceCommand as were
* passed to Tcl_TraceCommand. Reproduce the processing of [trace add
* execution/command]. Be careful to keep this code in sync with that.
*/
if (untraceFlags & TCL_TRACE_ANY_EXEC) {
untraceFlags |= TCL_TRACE_DELETE;
if (untraceFlags & (TCL_TRACE_ENTER_DURING_EXEC
| TCL_TRACE_LEAVE_DURING_EXEC)) {
untraceFlags |= (TCL_TRACE_ENTER_EXEC | TCL_TRACE_LEAVE_EXEC);
}
} else if (untraceFlags & TCL_TRACE_RENAME) {
untraceFlags |= TCL_TRACE_DELETE;
}
/*
* Remove the trace since TCL_TRACE_DESTROYED tells us to, or the
* command we're tracing has just gone away. Then decrement the
* clientData refCount that was set up by trace creation.
*
* Note that we save the (return) state of the interpreter to prevent
* bizarre error messages.
*/
state = Tcl_SaveInterpState(interp, TCL_OK);
Tcl_UntraceCommand(interp, oldName, untraceFlags,
TraceCommandProc, clientData);
(void) Tcl_RestoreInterpState(interp, state);
tcmdPtr->refCount--;
}
if ((--tcmdPtr->refCount) <= 0) {
ckfree((char *) tcmdPtr);
}
}
/*
*----------------------------------------------------------------------
*
* TclCheckExecutionTraces --
*
* Checks on all current command execution traces, and invokes functions
* which have been registered. This function can be used by other code
* which performs execution to unify the tracing system, so that
* execution traces will function for that other code.
*
* For instance extensions like [incr Tcl] which use their own execution
* technique can make use of Tcl's tracing.
*
* This function is called by 'TclEvalObjvInternal'
*
* Results:
* The return value is a standard Tcl completion code such as TCL_OK or
* TCL_ERROR, etc.
*
* Side effects:
* Those side effects made by any trace functions called.
*
*----------------------------------------------------------------------
*/
int
TclCheckExecutionTraces(
Tcl_Interp *interp, /* The current interpreter. */
const char *command, /* Pointer to beginning of the current command
* string. */
int numChars, /* The number of characters in 'command' which
* are part of the command string. */
Command *cmdPtr, /* Points to command's Command struct. */
int code, /* The current result code. */
int traceFlags, /* Current tracing situation. */
int objc, /* Number of arguments for the command. */
Tcl_Obj *const objv[]) /* Pointers to Tcl_Obj of each argument. */
{
Interp *iPtr = (Interp *) interp;
CommandTrace *tracePtr, *lastTracePtr;
ActiveCommandTrace active;
int curLevel;
int traceCode = TCL_OK;
Tcl_InterpState state = NULL;
if (cmdPtr->tracePtr == NULL) {
return traceCode;
}
curLevel = iPtr->varFramePtr->level;
active.nextPtr = iPtr->activeCmdTracePtr;
iPtr->activeCmdTracePtr = &active;
active.cmdPtr = cmdPtr;
lastTracePtr = NULL;
for (tracePtr = cmdPtr->tracePtr;
(traceCode == TCL_OK) && (tracePtr != NULL);
tracePtr = active.nextTracePtr) {
if (traceFlags & TCL_TRACE_LEAVE_EXEC) {
/*
* Execute the trace command in order of creation for "leave".
*/
active.reverseScan = 1;
active.nextTracePtr = NULL;
tracePtr = cmdPtr->tracePtr;
while (tracePtr->nextPtr != lastTracePtr) {
active.nextTracePtr = tracePtr;
tracePtr = tracePtr->nextPtr;
}
} else {
active.reverseScan = 0;
active.nextTracePtr = tracePtr->nextPtr;
}
if (tracePtr->traceProc == TraceCommandProc) {
TraceCommandInfo *tcmdPtr = (TraceCommandInfo *)
tracePtr->clientData;
if (tcmdPtr->flags != 0) {
tcmdPtr->curFlags = traceFlags | TCL_TRACE_EXEC_DIRECT;
tcmdPtr->curCode = code;
tcmdPtr->refCount++;
if (state == NULL) {
state = Tcl_SaveInterpState(interp, code);
}
traceCode = TraceExecutionProc((ClientData) tcmdPtr, interp,
curLevel, command, (Tcl_Command) cmdPtr, objc, objv);
if ((--tcmdPtr->refCount) <= 0) {
ckfree((char *) tcmdPtr);
}
}
}
if (active.nextTracePtr) {
lastTracePtr = active.nextTracePtr->nextPtr;
}
}
iPtr->activeCmdTracePtr = active.nextPtr;
if (state) {
(void) Tcl_RestoreInterpState(interp, state);
}
return(traceCode);
}
/*
*----------------------------------------------------------------------
*
* TclCheckInterpTraces --
*
* Checks on all current traces, and invokes functions which have been
* registered. This function can be used by other code which performs
* execution to unify the tracing system. For instance extensions like
* [incr Tcl] which use their own execution technique can make use of
* Tcl's tracing.
*
* This function is called by 'TclEvalObjvInternal'
*
* Results:
* The return value is a standard Tcl completion code such as TCL_OK or
* TCL_ERROR, etc.
*
* Side effects:
* Those side effects made by any trace functions called.
*
*----------------------------------------------------------------------
*/
int
TclCheckInterpTraces(
Tcl_Interp *interp, /* The current interpreter. */
const char *command, /* Pointer to beginning of the current command
* string. */
int numChars, /* The number of characters in 'command' which
* are part of the command string. */
Command *cmdPtr, /* Points to command's Command struct. */
int code, /* The current result code. */
int traceFlags, /* Current tracing situation. */
int objc, /* Number of arguments for the command. */
Tcl_Obj *const objv[]) /* Pointers to Tcl_Obj of each argument. */
{
Interp *iPtr = (Interp *) interp;
Trace *tracePtr, *lastTracePtr;
ActiveInterpTrace active;
int curLevel;
int traceCode = TCL_OK;
Tcl_InterpState state = NULL;
if ((iPtr->tracePtr == NULL)
|| (iPtr->flags & INTERP_TRACE_IN_PROGRESS)) {
return(traceCode);
}
curLevel = iPtr->numLevels;
active.nextPtr = iPtr->activeInterpTracePtr;
iPtr->activeInterpTracePtr = &active;
lastTracePtr = NULL;
for (tracePtr = iPtr->tracePtr;
(traceCode == TCL_OK) && (tracePtr != NULL);
tracePtr = active.nextTracePtr) {
if (traceFlags & TCL_TRACE_ENTER_EXEC) {
/*
* Execute the trace command in reverse order of creation for
* "enterstep" operation. The order is changed for "enterstep"
* instead of for "leavestep" as was done in
* TclCheckExecutionTraces because for step traces,
* Tcl_CreateObjTrace creates one more linked list of traces which
* results in one more reversal of trace invocation.
*/
active.reverseScan = 1;
active.nextTracePtr = NULL;
tracePtr = iPtr->tracePtr;
while (tracePtr->nextPtr != lastTracePtr) {
active.nextTracePtr = tracePtr;
tracePtr = tracePtr->nextPtr;
}
if (active.nextTracePtr) {
lastTracePtr = active.nextTracePtr->nextPtr;
}
} else {
active.reverseScan = 0;
active.nextTracePtr = tracePtr->nextPtr;
}
if (tracePtr->level > 0 && curLevel > tracePtr->level) {
continue;
}
if (!(tracePtr->flags & TCL_TRACE_EXEC_IN_PROGRESS)) {
/*
* The proc invoked might delete the traced command which which
* might try to free tracePtr. We want to use tracePtr until the
* end of this if section, so we use Tcl_Preserve() and
* Tcl_Release() to be sure it is not freed while we still need
* it.
*/
Tcl_Preserve((ClientData) tracePtr);
tracePtr->flags |= TCL_TRACE_EXEC_IN_PROGRESS;
if (state == NULL) {
state = Tcl_SaveInterpState(interp, code);
}
if (tracePtr->flags &
(TCL_TRACE_ENTER_EXEC | TCL_TRACE_LEAVE_EXEC)) {
/*
* New style trace.
*/
if (tracePtr->flags & traceFlags) {
if (tracePtr->proc == TraceExecutionProc) {
TraceCommandInfo *tcmdPtr = (TraceCommandInfo *)
tracePtr->clientData;
tcmdPtr->curFlags = traceFlags;
tcmdPtr->curCode = code;
}
traceCode = (tracePtr->proc)(tracePtr->clientData,
interp, curLevel, command, (Tcl_Command) cmdPtr,
objc, objv);
}
} else {
/*
* Old-style trace.
*/
if (traceFlags & TCL_TRACE_ENTER_EXEC) {
/*
* Old-style interpreter-wide traces only trigger before
* the command is executed.
*/
traceCode = CallTraceFunction(interp, tracePtr, cmdPtr,
command, numChars, objc, objv);
}
}
tracePtr->flags &= ~TCL_TRACE_EXEC_IN_PROGRESS;
Tcl_Release((ClientData) tracePtr);
}
}
iPtr->activeInterpTracePtr = active.nextPtr;
if (state) {
if (traceCode == TCL_OK) {
(void) Tcl_RestoreInterpState(interp, state);
} else {
Tcl_DiscardInterpState(state);
}
}
return(traceCode);
}
/*
*----------------------------------------------------------------------
*
* CallTraceFunction --
*
* Invokes a trace function registered with an interpreter. These
* functions trace command execution. Currently this trace function is
* called with the address of the string-based Tcl_CmdProc for the
* command, not the Tcl_ObjCmdProc.
*
* Results:
* None.
*
* Side effects:
* Those side effects made by the trace function.
*
*----------------------------------------------------------------------
*/
static int
CallTraceFunction(
Tcl_Interp *interp, /* The current interpreter. */
register Trace *tracePtr, /* Describes the trace function to call. */
Command *cmdPtr, /* Points to command's Command struct. */
const char *command, /* Points to the first character of the
* command's source before substitutions. */
int numChars, /* The number of characters in the command's
* source. */
register int objc, /* Number of arguments for the command. */
Tcl_Obj *const objv[]) /* Pointers to Tcl_Obj of each argument. */
{
Interp *iPtr = (Interp *) interp;
char *commandCopy;
int traceCode;
/*
* Copy the command characters into a new string.
*/
commandCopy = TclStackAlloc(interp, (unsigned) (numChars + 1));
memcpy(commandCopy, command, (size_t) numChars);
commandCopy[numChars] = '\0';
/*
* Call the trace function then free allocated storage.
*/
traceCode = (tracePtr->proc)(tracePtr->clientData, (Tcl_Interp *) iPtr,
iPtr->numLevels, commandCopy, (Tcl_Command) cmdPtr, objc, objv);
TclStackFree(interp, commandCopy);
return traceCode;
}
/*
*----------------------------------------------------------------------
*
* CommandObjTraceDeleted --
*
* Ensure the trace is correctly deleted by decrementing its refCount and
* only deleting if no other references exist.
*
* Results:
* None.
*
* Side effects:
* May release memory.
*
*----------------------------------------------------------------------
*/
static void
CommandObjTraceDeleted(
ClientData clientData)
{
TraceCommandInfo *tcmdPtr = (TraceCommandInfo *) clientData;
if ((--tcmdPtr->refCount) <= 0) {
ckfree((char *) tcmdPtr);
}
}
/*
*----------------------------------------------------------------------
*
* TraceExecutionProc --
*
* This function is invoked whenever code relevant to a 'trace execution'
* command is executed. It is called in one of two ways in Tcl's core:
*
* (i) by the TclCheckExecutionTraces, when an execution trace has been
* triggered.
* (ii) by TclCheckInterpTraces, when a prior execution trace has created
* a trace of the internals of a procedure, passing in this function as
* the one to be called.
*
* Results:
* The return value is a standard Tcl completion code such as TCL_OK or
* TCL_ERROR, etc.
*
* Side effects:
* May invoke an arbitrary Tcl procedure, and may create or delete an
* interpreter-wide trace.
*
*----------------------------------------------------------------------
*/
static int
TraceExecutionProc(
ClientData clientData,
Tcl_Interp *interp,
int level,
const char *command,
Tcl_Command cmdInfo,
int objc,
struct Tcl_Obj *const objv[])
{
int call = 0;
Interp *iPtr = (Interp *) interp;
TraceCommandInfo *tcmdPtr = (TraceCommandInfo *) clientData;
int flags = tcmdPtr->curFlags;
int code = tcmdPtr->curCode;
int traceCode = TCL_OK;
if (tcmdPtr->flags & TCL_TRACE_EXEC_IN_PROGRESS) {
/*
* Inside any kind of execution trace callback, we do not allow any
* further execution trace callbacks to be called for the same trace.
*/
return traceCode;
}
if (!Tcl_InterpDeleted(interp) && !Tcl_LimitExceeded(interp)) {
/*
* Check whether the current call is going to eval arbitrary Tcl code
* with a generated trace, or whether we are only going to setup
* interpreter-wide traces to implement the 'step' traces. This latter
* situation can happen if we create a command trace without either
* before or after operations, but with either of the step operations.
*/
if (flags & TCL_TRACE_EXEC_DIRECT) {
call = flags & tcmdPtr->flags &
(TCL_TRACE_ENTER_EXEC | TCL_TRACE_LEAVE_EXEC);
} else {
call = 1;
}
/*
* First, if we have returned back to the level at which we created an
* interpreter trace for enterstep and/or leavestep execution traces,
* we remove it here.
*/
if ((flags & TCL_TRACE_LEAVE_EXEC) && (tcmdPtr->stepTrace != NULL)
&& (level == tcmdPtr->startLevel)
&& (strcmp(command, tcmdPtr->startCmd) == 0)) {
Tcl_DeleteTrace(interp, tcmdPtr->stepTrace);
tcmdPtr->stepTrace = NULL;
if (tcmdPtr->startCmd != NULL) {
ckfree((char *) tcmdPtr->startCmd);
}
}
/*
* Second, create the tcl callback, if required.
*/
if (call) {
Tcl_DString cmd;
Tcl_DString sub;
int i, saveInterpFlags;
Tcl_DStringInit(&cmd);
Tcl_DStringAppend(&cmd, tcmdPtr->command, (int)tcmdPtr->length);
/*
* Append command with arguments.
*/
Tcl_DStringInit(&sub);
for (i = 0; i < objc; i++) {
Tcl_DStringAppendElement(&sub, Tcl_GetString(objv[i]));
}
Tcl_DStringAppendElement(&cmd, Tcl_DStringValue(&sub));
Tcl_DStringFree(&sub);
if (flags & TCL_TRACE_ENTER_EXEC) {
/*
* Append trace operation.
*/
if (flags & TCL_TRACE_EXEC_DIRECT) {
Tcl_DStringAppendElement(&cmd, "enter");
} else {
Tcl_DStringAppendElement(&cmd, "enterstep");
}
} else if (flags & TCL_TRACE_LEAVE_EXEC) {
Tcl_Obj *resultCode;
char *resultCodeStr;
/*
* Append result code.
*/
resultCode = Tcl_NewIntObj(code);
resultCodeStr = Tcl_GetString(resultCode);
Tcl_DStringAppendElement(&cmd, resultCodeStr);
Tcl_DecrRefCount(resultCode);
/*
* Append result string.
*/
Tcl_DStringAppendElement(&cmd, Tcl_GetStringResult(interp));
/*
* Append trace operation.
*/
if (flags & TCL_TRACE_EXEC_DIRECT) {
Tcl_DStringAppendElement(&cmd, "leave");
} else {
Tcl_DStringAppendElement(&cmd, "leavestep");
}
} else {
Tcl_Panic("TraceExecutionProc: bad flag combination");
}
/*
* Execute the command. We discard any object result the command
* returns.
*/
saveInterpFlags = iPtr->flags;
iPtr->flags |= INTERP_TRACE_IN_PROGRESS;
tcmdPtr->flags |= TCL_TRACE_EXEC_IN_PROGRESS;
tcmdPtr->refCount++;
/*
* This line can have quite arbitrary side-effects, including
* deleting the trace, the command being traced, or even the
* interpreter.
*/
traceCode = Tcl_Eval(interp, Tcl_DStringValue(&cmd));
tcmdPtr->flags &= ~TCL_TRACE_EXEC_IN_PROGRESS;
/*
* Restore the interp tracing flag to prevent cmd traces from
* affecting interp traces.
*/
iPtr->flags = saveInterpFlags;
if (tcmdPtr->flags == 0) {
flags |= TCL_TRACE_DESTROYED;
}
Tcl_DStringFree(&cmd);
}
/*
* Third, if there are any step execution traces for this proc, we
* register an interpreter trace to invoke enterstep and/or leavestep
* traces. We also need to save the current stack level and the proc
* string in startLevel and startCmd so that we can delete this
* interpreter trace when it reaches the end of this proc.
*/
if ((flags & TCL_TRACE_ENTER_EXEC) && (tcmdPtr->stepTrace == NULL)
&& (tcmdPtr->flags & (TCL_TRACE_ENTER_DURING_EXEC |
TCL_TRACE_LEAVE_DURING_EXEC))) {
register unsigned len = strlen(command) + 1;
tcmdPtr->startLevel = level;
tcmdPtr->startCmd = ckalloc(len);
memcpy(tcmdPtr->startCmd, command, len);
tcmdPtr->refCount++;
tcmdPtr->stepTrace = Tcl_CreateObjTrace(interp, 0,
(tcmdPtr->flags & TCL_TRACE_ANY_EXEC) >> 2,
TraceExecutionProc, (ClientData)tcmdPtr,
CommandObjTraceDeleted);
}
}
if (flags & TCL_TRACE_DESTROYED) {
if (tcmdPtr->stepTrace != NULL) {
Tcl_DeleteTrace(interp, tcmdPtr->stepTrace);
tcmdPtr->stepTrace = NULL;
if (tcmdPtr->startCmd != NULL) {
ckfree(tcmdPtr->startCmd);
}
}
}
if (call) {
if ((--tcmdPtr->refCount) <= 0) {
ckfree((char *) tcmdPtr);
}
}
return traceCode;
}
/*
*----------------------------------------------------------------------
*
* TraceVarProc --
*
* This function is called to handle variable accesses that have been
* traced using the "trace" command.
*
* Results:
* Normally returns NULL. If the trace command returns an error, then
* this function returns an error string.
*
* Side effects:
* Depends on the command associated with the trace.
*
*----------------------------------------------------------------------
*/
/* ARGSUSED */
static char *
TraceVarProc(
ClientData clientData, /* Information about the variable trace. */
Tcl_Interp *interp, /* Interpreter containing variable. */
const char *name1, /* Name of variable or array. */
const char *name2, /* Name of element within array; NULL means
* scalar variable is being referenced. */
int flags) /* OR-ed bits giving operation and other
* information. */
{
TraceVarInfo *tvarPtr = (TraceVarInfo *) clientData;
char *result;
int code, destroy = 0;
Tcl_DString cmd;
/*
* We might call Tcl_Eval() below, and that might evaluate [trace vdelete]
* which might try to free tvarPtr. We want to use tvarPtr until the end
* of this function, so we use Tcl_Preserve() and Tcl_Release() to be sure
* it is not freed while we still need it.
*/
result = NULL;
if ((tvarPtr->flags & flags) && !Tcl_InterpDeleted(interp)
&& !Tcl_LimitExceeded(interp)) {
if (tvarPtr->length != (size_t) 0) {
/*
* Generate a command to execute by appending list elements for
* the two variable names and the operation.
*/
Tcl_DStringInit(&cmd);
Tcl_DStringAppend(&cmd, tvarPtr->command, (int) tvarPtr->length);
Tcl_DStringAppendElement(&cmd, name1);
Tcl_DStringAppendElement(&cmd, (name2 ? name2 : ""));
#ifndef TCL_REMOVE_OBSOLETE_TRACES
if (tvarPtr->flags & TCL_TRACE_OLD_STYLE) {
if (flags & TCL_TRACE_ARRAY) {
Tcl_DStringAppend(&cmd, " a", 2);
} else if (flags & TCL_TRACE_READS) {
Tcl_DStringAppend(&cmd, " r", 2);
} else if (flags & TCL_TRACE_WRITES) {
Tcl_DStringAppend(&cmd, " w", 2);
} else if (flags & TCL_TRACE_UNSETS) {
Tcl_DStringAppend(&cmd, " u", 2);
}
} else {
#endif
if (flags & TCL_TRACE_ARRAY) {
Tcl_DStringAppend(&cmd, " array", 6);
} else if (flags & TCL_TRACE_READS) {
Tcl_DStringAppend(&cmd, " read", 5);
} else if (flags & TCL_TRACE_WRITES) {
Tcl_DStringAppend(&cmd, " write", 6);
} else if (flags & TCL_TRACE_UNSETS) {
Tcl_DStringAppend(&cmd, " unset", 6);
}
#ifndef TCL_REMOVE_OBSOLETE_TRACES
}
#endif
/*
* Execute the command. We discard any object result the command
* returns.
*
* Add the TCL_TRACE_DESTROYED flag to tvarPtr to indicate to
* other areas that this will be destroyed by us, otherwise a
* double-free might occur depending on what the eval does.
*/
if ((flags & TCL_TRACE_DESTROYED)
&& !(tvarPtr->flags & TCL_TRACE_DESTROYED)) {
destroy = 1;
tvarPtr->flags |= TCL_TRACE_DESTROYED;
}
code = Tcl_EvalEx(interp, Tcl_DStringValue(&cmd),
Tcl_DStringLength(&cmd), 0);
if (code != TCL_OK) { /* copy error msg to result */
Tcl_Obj *errMsgObj = Tcl_GetObjResult(interp);
Tcl_IncrRefCount(errMsgObj);
result = (char *) errMsgObj;
}
Tcl_DStringFree(&cmd);
}
}
if (destroy && result != NULL) {
register Tcl_Obj *errMsgObj = (Tcl_Obj *) result;
Tcl_DecrRefCount(errMsgObj);
result = NULL;
}
return result;
}
/*
*----------------------------------------------------------------------
*
* Tcl_CreateObjTrace --
*
* Arrange for a function to be called to trace command execution.
*
* Results:
* The return value is a token for the trace, which may be passed to
* Tcl_DeleteTrace to eliminate the trace.
*
* Side effects:
* From now on, proc will be called just before a command function is
* called to execute a Tcl command. Calls to proc will have the following
* form:
*
* void proc(ClientData clientData,
* Tcl_Interp * interp,
* int level,
* const char * command,
* Tcl_Command commandInfo,
* int objc,
* Tcl_Obj *const objv[]);
*
* The 'clientData' and 'interp' arguments to 'proc' will be the same as
* the arguments to Tcl_CreateObjTrace. The 'level' argument gives the
* nesting depth of command interpretation within the interpreter. The
* 'command' argument is the ASCII text of the command being evaluated -
* before any substitutions are performed. The 'commandInfo' argument
* gives a handle to the command procedure that will be evaluated. The
* 'objc' and 'objv' parameters give the parameter vector that will be
* passed to the command procedure. Proc does not return a value.
*
* It is permissible for 'proc' to call Tcl_SetCommandTokenInfo to change
* the command procedure or client data for the command being evaluated,
* and these changes will take effect with the current evaluation.
*
* The 'level' argument specifies the maximum nesting level of calls to
* be traced. If the execution depth of the interpreter exceeds 'level',
* the trace callback is not executed.
*
* The 'flags' argument is either zero or the value,
* TCL_ALLOW_INLINE_COMPILATION. If the TCL_ALLOW_INLINE_COMPILATION flag
* is not present, the bytecode compiler will not generate inline code
* for Tcl's built-in commands. This behavior will have a significant
* impact on performance, but will ensure that all command evaluations
* are traced. If the TCL_ALLOW_INLINE_COMPILATION flag is present, the
* bytecode compiler will have its normal behavior of compiling in-line
* code for some of Tcl's built-in commands. In this case, the tracing
* will be imprecise - in-line code will not be traced - but run-time
* performance will be improved. The latter behavior is desired for many
* applications such as profiling of run time.
*
* When the trace is deleted, the 'delProc' function will be invoked,
* passing it the original client data.
*
*----------------------------------------------------------------------
*/
Tcl_Trace
Tcl_CreateObjTrace(
Tcl_Interp *interp, /* Tcl interpreter */
int level, /* Maximum nesting level */
int flags, /* Flags, see above */
Tcl_CmdObjTraceProc *proc, /* Trace callback */
ClientData clientData, /* Client data for the callback */
Tcl_CmdObjTraceDeleteProc *delProc)
/* Function to call when trace is deleted */
{
register Trace *tracePtr;
register Interp *iPtr = (Interp *) interp;
/*
* Test if this trace allows inline compilation of commands.
*/
if (!(flags & TCL_ALLOW_INLINE_COMPILATION)) {
if (iPtr->tracesForbiddingInline == 0) {
/*
* When the first trace forbidding inline compilation is created,
* invalidate existing compiled code for this interpreter and
* arrange (by setting the DONT_COMPILE_CMDS_INLINE flag) that
* when compiling new code, no commands will be compiled inline
* (i.e., into an inline sequence of instructions). We do this
* because commands that were compiled inline will never result in
* a command trace being called.
*/
iPtr->compileEpoch++;
iPtr->flags |= DONT_COMPILE_CMDS_INLINE;
}
iPtr->tracesForbiddingInline++;
}
tracePtr = (Trace *) ckalloc(sizeof(Trace));
tracePtr->level = level;
tracePtr->proc = proc;
tracePtr->clientData = clientData;
tracePtr->delProc = delProc;
tracePtr->nextPtr = iPtr->tracePtr;
tracePtr->flags = flags;
iPtr->tracePtr = tracePtr;
return (Tcl_Trace) tracePtr;
}
/*
*----------------------------------------------------------------------
*
* Tcl_CreateTrace --
*
* Arrange for a function to be called to trace command execution.
*
* Results:
* The return value is a token for the trace, which may be passed to
* Tcl_DeleteTrace to eliminate the trace.
*
* Side effects:
* From now on, proc will be called just before a command procedure is
* called to execute a Tcl command. Calls to proc will have the following
* form:
*
* void
* proc(clientData, interp, level, command, cmdProc, cmdClientData,
* argc, argv)
* ClientData clientData;
* Tcl_Interp *interp;
* int level;
* char *command;
* int (*cmdProc)();
* ClientData cmdClientData;
* int argc;
* char **argv;
* {
* }
*
* The clientData and interp arguments to proc will be the same as the
* corresponding arguments to this function. Level gives the nesting
* level of command interpretation for this interpreter (0 corresponds to
* top level). Command gives the ASCII text of the raw command, cmdProc
* and cmdClientData give the function that will be called to process the
* command and the ClientData value it will receive, and argc and argv
* give the arguments to the command, after any argument parsing and
* substitution. Proc does not return a value.
*
*----------------------------------------------------------------------
*/
Tcl_Trace
Tcl_CreateTrace(
Tcl_Interp *interp, /* Interpreter in which to create trace. */
int level, /* Only call proc for commands at nesting
* level<=argument level (1=>top level). */
Tcl_CmdTraceProc *proc, /* Function to call before executing each
* command. */
ClientData clientData) /* Arbitrary value word to pass to proc. */
{
StringTraceData *data = (StringTraceData *)
ckalloc(sizeof(StringTraceData));
data->clientData = clientData;
data->proc = proc;
return Tcl_CreateObjTrace(interp, level, 0, StringTraceProc,
(ClientData) data, StringTraceDeleteProc);
}
/*
*----------------------------------------------------------------------
*
* StringTraceProc --
*
* Invoke a string-based trace function from an object-based callback.
*
* Results:
* None.
*
* Side effects:
* Whatever the string-based trace function does.
*
*----------------------------------------------------------------------
*/
static int
StringTraceProc(
ClientData clientData,
Tcl_Interp *interp,
int level,
const char *command,
Tcl_Command commandInfo,
int objc,
Tcl_Obj *const *objv)
{
StringTraceData *data = (StringTraceData *) clientData;
Command *cmdPtr = (Command *) commandInfo;
const char **argv; /* Args to pass to string trace proc */
int i;
/*
* This is a bit messy because we have to emulate the old trace interface,
* which uses strings for everything.
*/
argv = (const char **) TclStackAlloc(interp,
(unsigned) ((objc + 1) * sizeof(const char *)));
for (i = 0; i < objc; i++) {
argv[i] = Tcl_GetString(objv[i]);
}
argv[objc] = 0;
/*
* Invoke the command function. Note that we cast away const-ness on two
* parameters for compatibility with legacy code; the code MUST NOT modify
* either command or argv.
*/
(data->proc)(data->clientData, interp, level, (char *) command,
cmdPtr->proc, cmdPtr->clientData, objc, argv);
TclStackFree(interp, (void *) argv);
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* StringTraceDeleteProc --
*
* Clean up memory when a string-based trace is deleted.
*
* Results:
* None.
*
* Side effects:
* Allocated memory is returned to the system.
*
*----------------------------------------------------------------------
*/
static void
StringTraceDeleteProc(
ClientData clientData)
{
ckfree((char *) clientData);
}
/*
*----------------------------------------------------------------------
*
* Tcl_DeleteTrace --
*
* Remove a trace.
*
* Results:
* None.
*
* Side effects:
* From now on there will be no more calls to the function given in
* trace.
*
*----------------------------------------------------------------------
*/
void
Tcl_DeleteTrace(
Tcl_Interp *interp, /* Interpreter that contains trace. */
Tcl_Trace trace) /* Token for trace (returned previously by
* Tcl_CreateTrace). */
{
Interp *iPtr = (Interp *) interp;
Trace *prevPtr, *tracePtr = (Trace *) trace;
register Trace **tracePtr2 = &(iPtr->tracePtr);
ActiveInterpTrace *activePtr;
/*
* Locate the trace entry in the interpreter's trace list, and remove it
* from the list.
*/
prevPtr = NULL;
while ((*tracePtr2) != NULL && (*tracePtr2) != tracePtr) {
prevPtr = *tracePtr2;
tracePtr2 = &((*tracePtr2)->nextPtr);
}
if (*tracePtr2 == NULL) {
return;
}
(*tracePtr2) = (*tracePtr2)->nextPtr;
/*
* The code below makes it possible to delete traces while traces are
* active: it makes sure that the deleted trace won't be processed by
* TclCheckInterpTraces.
*/
for (activePtr = iPtr->activeInterpTracePtr; activePtr != NULL;
activePtr = activePtr->nextPtr) {
if (activePtr->nextTracePtr == tracePtr) {
if (activePtr->reverseScan) {
activePtr->nextTracePtr = prevPtr;
} else {
activePtr->nextTracePtr = tracePtr->nextPtr;
}
}
}
/*
* If the trace forbids bytecode compilation, change the interpreter's
* state. If bytecode compilation is now permitted, flag the fact and
* advance the compilation epoch so that procs will be recompiled to take
* advantage of it.
*/
if (!(tracePtr->flags & TCL_ALLOW_INLINE_COMPILATION)) {
iPtr->tracesForbiddingInline--;
if (iPtr->tracesForbiddingInline == 0) {
iPtr->flags &= ~DONT_COMPILE_CMDS_INLINE;
iPtr->compileEpoch++;
}
}
/*
* Execute any delete callback.
*/
if (tracePtr->delProc != NULL) {
(tracePtr->delProc)(tracePtr->clientData);
}
/*
* Delete the trace object.
*/
Tcl_EventuallyFree((char *) tracePtr, TCL_DYNAMIC);
}
/*
*----------------------------------------------------------------------
*
* TclTraceVarExists --
*
* This is called from info exists. We need to trigger read and/or array
* traces because they may end up creating a variable that doesn't
* currently exist.
*
* Results:
* A pointer to the Var structure, or NULL.
*
* Side effects:
* May fill in error messages in the interp.
*
*----------------------------------------------------------------------
*/
Var *
TclVarTraceExists(
Tcl_Interp *interp, /* The interpreter */
const char *varName) /* The variable name */
{
Var *varPtr;
Var *arrayPtr;
/*
* The choice of "create" flag values is delicate here, and matches the
* semantics of GetVar. Things are still not perfect, however, because if
* you do "info exists x" you get a varPtr and therefore trigger traces.
* However, if you do "info exists x(i)", then you only get a varPtr if x
* is already known to be an array. Otherwise you get NULL, and no trace
* is triggered. This matches Tcl 7.6 semantics.
*/
varPtr = TclLookupVar(interp, varName, NULL, 0, "access",
/*createPart1*/ 0, /*createPart2*/ 1, &arrayPtr);
if (varPtr == NULL) {
return NULL;
}
if ((varPtr->flags & VAR_TRACED_READ)
|| (arrayPtr && (arrayPtr->flags & VAR_TRACED_READ))) {
TclCallVarTraces((Interp *)interp, arrayPtr, varPtr, varName, NULL,
TCL_TRACE_READS, /* leaveErrMsg */ 0);
}
/*
* If the variable doesn't exist anymore and no-one's using it, then free
* up the relevant structures and hash table entries.
*/
if (TclIsVarUndefined(varPtr)) {
TclCleanupVar(varPtr, arrayPtr);
return NULL;
}
return varPtr;
}
/*
*----------------------------------------------------------------------
*
* TclCallVarTraces --
*
* This function is invoked to find and invoke relevant trace functions
* associated with a particular operation on a variable. This function
* invokes traces both on the variable and on its containing array (where
* relevant).
*
* Results:
* Returns TCL_OK to indicate normal operation. Returns TCL_ERROR if
* invocation of a trace function indicated an error. When TCL_ERROR is
* returned and leaveErrMsg is true, then the errorInfo field of iPtr has
* information about the error placed in it.
*
* Side effects:
* Almost anything can happen, depending on trace; this function itself
* doesn't have any side effects.
*
*----------------------------------------------------------------------
*/
int
TclObjCallVarTraces(
Interp *iPtr, /* Interpreter containing variable. */
register Var *arrayPtr, /* Pointer to array variable that contains the
* variable, or NULL if the variable isn't an
* element of an array. */
Var *varPtr, /* Variable whose traces are to be invoked. */
Tcl_Obj *part1Ptr,
Tcl_Obj *part2Ptr, /* Variable's two-part name. */
int flags, /* Flags passed to trace functions: indicates
* what's happening to variable, plus maybe
* TCL_GLOBAL_ONLY or TCL_NAMESPACE_ONLY */
int leaveErrMsg, /* If true, and one of the traces indicates an
* error, then leave an error message and
* stack trace information in *iPTr. */
int index) /* Index into the local variable table of the
* variable, or -1. Only used when part1Ptr is
* NULL. */
{
char *part1, *part2;
if (!part1Ptr) {
part1Ptr = localName(iPtr->varFramePtr, index);
}
part1 = TclGetString(part1Ptr);
part2 = part2Ptr? TclGetString(part2Ptr) : NULL;
return TclCallVarTraces(iPtr, arrayPtr, varPtr, part1, part2, flags,
leaveErrMsg);
}
int
TclCallVarTraces(
Interp *iPtr, /* Interpreter containing variable. */
register Var *arrayPtr, /* Pointer to array variable that contains the
* variable, or NULL if the variable isn't an
* element of an array. */
Var *varPtr, /* Variable whose traces are to be invoked. */
const char *part1,
const char *part2, /* Variable's two-part name. */
int flags, /* Flags passed to trace functions: indicates
* what's happening to variable, plus maybe
* TCL_GLOBAL_ONLY or TCL_NAMESPACE_ONLY */
int leaveErrMsg) /* If true, and one of the traces indicates an
* error, then leave an error message and
* stack trace information in *iPTr. */
{
register VarTrace *tracePtr;
ActiveVarTrace active;
char *result;
const char *openParen, *p;
Tcl_DString nameCopy;
int copiedName;
int code = TCL_OK;
int disposeFlags = 0;
Tcl_InterpState state = NULL;
Tcl_HashEntry *hPtr;
int traceflags = flags & VAR_ALL_TRACES;
/*
* If there are already similar trace functions active for the variable,
* don't call them again.
*/
if (TclIsVarTraceActive(varPtr)) {
return code;
}
TclSetVarTraceActive(varPtr);
if (TclIsVarInHash(varPtr)) {
VarHashRefCount(varPtr)++;
}
if (arrayPtr && TclIsVarInHash(arrayPtr)) {
VarHashRefCount(arrayPtr)++;
}
/*
* If the variable name hasn't been parsed into array name and element, do
* it here. If there really is an array element, make a copy of the
* original name so that NULLs can be inserted into it to separate the
* names (can't modify the name string in place, because the string might
* get used by the callbacks we invoke).
*/
copiedName = 0;
if (part2 == NULL) {
for (p = part1; *p ; p++) {
if (*p == '(') {
openParen = p;
do {
p++;
} while (*p != '\0');
p--;
if (*p == ')') {
int offset = (openParen - part1);
char *newPart1;
Tcl_DStringInit(&nameCopy);
Tcl_DStringAppend(&nameCopy, part1, (p-part1));
newPart1 = Tcl_DStringValue(&nameCopy);
newPart1[offset] = 0;
part1 = newPart1;
part2 = newPart1 + offset + 1;
copiedName = 1;
}
break;
}
}
}
/*
* Ignore any caller-provided TCL_INTERP_DESTROYED flag. Only we can
* set it correctly.
*/
flags &= ~TCL_INTERP_DESTROYED;
/*
* Invoke traces on the array containing the variable, if relevant.
*/
result = NULL;
active.nextPtr = iPtr->activeVarTracePtr;
iPtr->activeVarTracePtr = &active;
Tcl_Preserve((ClientData) iPtr);
if (arrayPtr && !TclIsVarTraceActive(arrayPtr)
&& (arrayPtr->flags & traceflags)) {
hPtr = Tcl_FindHashEntry(&iPtr->varTraces, (char *) arrayPtr);
active.varPtr = arrayPtr;
for (tracePtr = (VarTrace *) Tcl_GetHashValue(hPtr);
tracePtr != NULL; tracePtr = active.nextTracePtr) {
active.nextTracePtr = tracePtr->nextPtr;
if (!(tracePtr->flags & flags)) {
continue;
}
Tcl_Preserve((ClientData) tracePtr);
if (state == NULL) {
state = Tcl_SaveInterpState((Tcl_Interp *)iPtr, code);
}
if (Tcl_InterpDeleted((Tcl_Interp *)iPtr)) {
flags |= TCL_INTERP_DESTROYED;
}
result = (*tracePtr->traceProc)(tracePtr->clientData,
(Tcl_Interp *) iPtr, part1, part2, flags);
if (result != NULL) {
if (flags & TCL_TRACE_UNSETS) {
/*
* Ignore errors in unset traces.
*/
DisposeTraceResult(tracePtr->flags, result);
} else {
disposeFlags = tracePtr->flags;
code = TCL_ERROR;
}
}
Tcl_Release((ClientData) tracePtr);
if (code == TCL_ERROR) {
goto done;
}
}
}
/*
* Invoke traces on the variable itself.
*/
if (flags & TCL_TRACE_UNSETS) {
flags |= TCL_TRACE_DESTROYED;
}
active.varPtr = varPtr;
if (varPtr->flags & traceflags) {
hPtr = Tcl_FindHashEntry(&iPtr->varTraces, (char *) varPtr);
for (tracePtr = (VarTrace *) Tcl_GetHashValue(hPtr);
tracePtr != NULL; tracePtr = active.nextTracePtr) {
active.nextTracePtr = tracePtr->nextPtr;
if (!(tracePtr->flags & flags)) {
continue;
}
Tcl_Preserve((ClientData) tracePtr);
if (state == NULL) {
state = Tcl_SaveInterpState((Tcl_Interp *)iPtr, code);
}
if (Tcl_InterpDeleted((Tcl_Interp *)iPtr)) {
flags |= TCL_INTERP_DESTROYED;
}
result = (*tracePtr->traceProc)(tracePtr->clientData,
(Tcl_Interp *) iPtr, part1, part2, flags);
if (result != NULL) {
if (flags & TCL_TRACE_UNSETS) {
/*
* Ignore errors in unset traces.
*/
DisposeTraceResult(tracePtr->flags, result);
} else {
disposeFlags = tracePtr->flags;
code = TCL_ERROR;
}
}
Tcl_Release((ClientData) tracePtr);
if (code == TCL_ERROR) {
goto done;
}
}
}
/*
* Restore the variable's flags, remove the record of our active traces,
* and then return.
*/
done:
if (code == TCL_ERROR) {
if (leaveErrMsg) {
const char *verb = "";
const char *type = "";
switch (flags&(TCL_TRACE_READS|TCL_TRACE_WRITES|TCL_TRACE_ARRAY)) {
case TCL_TRACE_READS:
verb = "read";
type = verb;
break;
case TCL_TRACE_WRITES:
verb = "set";
type = "write";
break;
case TCL_TRACE_ARRAY:
verb = "trace array";
type = "array";
break;
}
if (disposeFlags & TCL_TRACE_RESULT_OBJECT) {
Tcl_SetObjResult((Tcl_Interp *)iPtr, (Tcl_Obj *) result);
} else {
Tcl_SetResult((Tcl_Interp *)iPtr, result, TCL_STATIC);
}
Tcl_AddErrorInfo((Tcl_Interp *)iPtr, "");
Tcl_AppendObjToErrorInfo((Tcl_Interp *)iPtr, Tcl_ObjPrintf(
"\n (%s trace on \"%s%s%s%s\")", type, part1,
(part2 ? "(" : ""), (part2 ? part2 : ""),
(part2 ? ")" : "") ));
if (disposeFlags & TCL_TRACE_RESULT_OBJECT) {
TclVarErrMsg((Tcl_Interp *) iPtr, part1, part2, verb,
Tcl_GetString((Tcl_Obj *) result));
} else {
TclVarErrMsg((Tcl_Interp *) iPtr, part1, part2, verb, result);
}
iPtr->flags &= ~(ERR_ALREADY_LOGGED);
Tcl_DiscardInterpState(state);
} else {
(void) Tcl_RestoreInterpState((Tcl_Interp *)iPtr, state);
}
DisposeTraceResult(disposeFlags,result);
} else if (state) {
if (code == TCL_OK) {
code = Tcl_RestoreInterpState((Tcl_Interp *)iPtr, state);
} else {
Tcl_DiscardInterpState(state);
}
}
if (arrayPtr && TclIsVarInHash(arrayPtr)) {
VarHashRefCount(arrayPtr)--;
}
if (copiedName) {
Tcl_DStringFree(&nameCopy);
}
TclClearVarTraceActive(varPtr);
if (TclIsVarInHash(varPtr)) {
VarHashRefCount(varPtr)--;
}
iPtr->activeVarTracePtr = active.nextPtr;
Tcl_Release((ClientData) iPtr);
return code;
}
/*
*----------------------------------------------------------------------
*
* DisposeTraceResult--
*
* This function is called to dispose of the result returned from a trace
* function. The disposal method appropriate to the type of result is
* determined by flags.
*
* Results:
* None.
*
* Side effects:
* The memory allocated for the trace result may be freed.
*
*----------------------------------------------------------------------
*/
static void
DisposeTraceResult(
int flags, /* Indicates type of result to determine
* proper disposal method. */
char *result) /* The result returned from a trace function
* to be disposed. */
{
if (flags & TCL_TRACE_RESULT_DYNAMIC) {
ckfree(result);
} else if (flags & TCL_TRACE_RESULT_OBJECT) {
Tcl_DecrRefCount((Tcl_Obj *) result);
}
}
/*
*----------------------------------------------------------------------
*
* Tcl_UntraceVar --
*
* Remove a previously-created trace for a variable.
*
* Results:
* None.
*
* Side effects:
* If there exists a trace for the variable given by varName with the
* given flags, proc, and clientData, then that trace is removed.
*
*----------------------------------------------------------------------
*/
void
Tcl_UntraceVar(
Tcl_Interp *interp, /* Interpreter containing variable. */
const char *varName, /* Name of variable; may end with "(index)" to
* signify an array reference. */
int flags, /* OR-ed collection of bits describing current
* trace, including any of TCL_TRACE_READS,
* TCL_TRACE_WRITES, TCL_TRACE_UNSETS,
* TCL_GLOBAL_ONLY and TCL_NAMESPACE_ONLY. */
Tcl_VarTraceProc *proc, /* Function assocated with trace. */
ClientData clientData) /* Arbitrary argument to pass to proc. */
{
Tcl_UntraceVar2(interp, varName, NULL, flags, proc, clientData);
}
/*
*----------------------------------------------------------------------
*
* Tcl_UntraceVar2 --
*
* Remove a previously-created trace for a variable.
*
* Results:
* None.
*
* Side effects:
* If there exists a trace for the variable given by part1 and part2 with
* the given flags, proc, and clientData, then that trace is removed.
*
*----------------------------------------------------------------------
*/
void
Tcl_UntraceVar2(
Tcl_Interp *interp, /* Interpreter containing variable. */
const char *part1, /* Name of variable or array. */
const char *part2, /* Name of element within array; NULL means
* trace applies to scalar variable or array
* as-a-whole. */
int flags, /* OR-ed collection of bits describing current
* trace, including any of TCL_TRACE_READS,
* TCL_TRACE_WRITES, TCL_TRACE_UNSETS,
* TCL_GLOBAL_ONLY, and TCL_NAMESPACE_ONLY. */
Tcl_VarTraceProc *proc, /* Function assocated with trace. */
ClientData clientData) /* Arbitrary argument to pass to proc. */
{
register VarTrace *tracePtr;
VarTrace *prevPtr, *nextPtr;
Var *varPtr, *arrayPtr;
Interp *iPtr = (Interp *) interp;
ActiveVarTrace *activePtr;
int flagMask, allFlags = 0;
Tcl_HashEntry *hPtr;
/*
* Set up a mask to mask out the parts of the flags that we are not
* interested in now.
*/
flagMask = TCL_GLOBAL_ONLY | TCL_NAMESPACE_ONLY;
varPtr = TclLookupVar(interp, part1, part2, flags & flagMask, /*msg*/ NULL,
/*createPart1*/ 0, /*createPart2*/ 0, &arrayPtr);
if (varPtr == NULL || !(varPtr->flags & VAR_ALL_TRACES & flags)) {
return;
}
/*
* Set up a mask to mask out the parts of the flags that we are not
* interested in now.
*/
flagMask = TCL_TRACE_READS | TCL_TRACE_WRITES | TCL_TRACE_UNSETS |
TCL_TRACE_ARRAY | TCL_TRACE_RESULT_DYNAMIC | TCL_TRACE_RESULT_OBJECT;
#ifndef TCL_REMOVE_OBSOLETE_TRACES
flagMask |= TCL_TRACE_OLD_STYLE;
#endif
flags &= flagMask;
hPtr = Tcl_FindHashEntry(&iPtr->varTraces,
(char *) varPtr);
for (tracePtr = (VarTrace *) Tcl_GetHashValue(hPtr), prevPtr = NULL; ;
prevPtr = tracePtr, tracePtr = tracePtr->nextPtr) {
if (tracePtr == NULL) {
goto updateFlags;
}
if ((tracePtr->traceProc == proc) && (tracePtr->flags == flags)
&& (tracePtr->clientData == clientData)) {
break;
}
allFlags |= tracePtr->flags;
}
/*
* The code below makes it possible to delete traces while traces are
* active: it makes sure that the deleted trace won't be processed by
* TclCallVarTraces.
*/
for (activePtr = iPtr->activeVarTracePtr; activePtr != NULL;
activePtr = activePtr->nextPtr) {
if (activePtr->nextTracePtr == tracePtr) {
activePtr->nextTracePtr = tracePtr->nextPtr;
}
}
nextPtr = tracePtr->nextPtr;
if (prevPtr == NULL) {
if (nextPtr) {
Tcl_SetHashValue(hPtr, nextPtr);
} else {
Tcl_DeleteHashEntry(hPtr);
}
} else {
prevPtr->nextPtr = nextPtr;
}
tracePtr->nextPtr = NULL;
Tcl_EventuallyFree((ClientData) tracePtr, TCL_DYNAMIC);
for (tracePtr = nextPtr; tracePtr != NULL;
tracePtr = tracePtr->nextPtr) {
allFlags |= tracePtr->flags;
}
updateFlags:
varPtr->flags &= ~VAR_ALL_TRACES;
if (allFlags & VAR_ALL_TRACES) {
varPtr->flags |= (allFlags & VAR_ALL_TRACES);
} else if (TclIsVarUndefined(varPtr)) {
/*
* If this is the last trace on the variable, and the variable is
* unset and unused, then free up the variable.
*/
TclCleanupVar(varPtr, NULL);
}
}
/*
*----------------------------------------------------------------------
*
* Tcl_VarTraceInfo --
*
* Return the clientData value associated with a trace on a variable.
* This function can also be used to step through all of the traces on a
* particular variable that have the same trace function.
*
* Results:
* The return value is the clientData value associated with a trace on
* the given variable. Information will only be returned for a trace with
* proc as trace function. If the clientData argument is NULL then the
* first such trace is returned; otherwise, the next relevant one after
* the one given by clientData will be returned. If the variable doesn't
* exist, or if there are no (more) traces for it, then NULL is returned.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
ClientData
Tcl_VarTraceInfo(
Tcl_Interp *interp, /* Interpreter containing variable. */
const char *varName, /* Name of variable; may end with "(index)" to
* signify an array reference. */
int flags, /* OR-ed combo or TCL_GLOBAL_ONLY,
* TCL_NAMESPACE_ONLY (can be 0). */
Tcl_VarTraceProc *proc, /* Function assocated with trace. */
ClientData prevClientData) /* If non-NULL, gives last value returned by
* this function, so this call will return the
* next trace after that one. If NULL, this
* call will return the first trace. */
{
return Tcl_VarTraceInfo2(interp, varName, NULL, flags, proc,
prevClientData);
}
/*
*----------------------------------------------------------------------
*
* Tcl_VarTraceInfo2 --
*
* Same as Tcl_VarTraceInfo, except takes name in two pieces instead of
* one.
*
* Results:
* Same as Tcl_VarTraceInfo.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
ClientData
Tcl_VarTraceInfo2(
Tcl_Interp *interp, /* Interpreter containing variable. */
const char *part1, /* Name of variable or array. */
const char *part2, /* Name of element within array; NULL means
* trace applies to scalar variable or array
* as-a-whole. */
int flags, /* OR-ed combination of TCL_GLOBAL_ONLY,
* TCL_NAMESPACE_ONLY. */
Tcl_VarTraceProc *proc, /* Function assocated with trace. */
ClientData prevClientData) /* If non-NULL, gives last value returned by
* this function, so this call will return the
* next trace after that one. If NULL, this
* call will return the first trace. */
{
Interp *iPtr = (Interp *) interp;
register VarTrace *tracePtr;
Var *varPtr, *arrayPtr;
Tcl_HashEntry *hPtr;
varPtr = TclLookupVar(interp, part1, part2,
flags & (TCL_GLOBAL_ONLY|TCL_NAMESPACE_ONLY), /*msg*/ NULL,
/*createPart1*/ 0, /*createPart2*/ 0, &arrayPtr);
if (varPtr == NULL) {
return NULL;
}
/*
* Find the relevant trace, if any, and return its clientData.
*/
hPtr = Tcl_FindHashEntry(&iPtr->varTraces,
(char *) varPtr);
if (hPtr) {
tracePtr = Tcl_GetHashValue(hPtr);
if (prevClientData != NULL) {
for ( ; tracePtr != NULL; tracePtr = tracePtr->nextPtr) {
if ((tracePtr->clientData == prevClientData)
&& (tracePtr->traceProc == proc)) {
tracePtr = tracePtr->nextPtr;
break;
}
}
}
for (; tracePtr!=NULL ; tracePtr=tracePtr->nextPtr) {
if (tracePtr->traceProc == proc) {
return tracePtr->clientData;
}
}
}
return NULL;
}
/*
*----------------------------------------------------------------------
*
* Tcl_TraceVar --
*
* Arrange for reads and/or writes to a variable to cause a function to
* be invoked, which can monitor the operations and/or change their
* actions.
*
* Results:
* A standard Tcl return value.
*
* Side effects:
* A trace is set up on the variable given by varName, such that future
* references to the variable will be intermediated by proc. See the
* manual entry for complete details on the calling sequence for proc.
* The variable's flags are updated.
*
*----------------------------------------------------------------------
*/
int
Tcl_TraceVar(
Tcl_Interp *interp, /* Interpreter in which variable is to be
* traced. */
const char *varName, /* Name of variable; may end with "(index)" to
* signify an array reference. */
int flags, /* OR-ed collection of bits, including any of
* TCL_TRACE_READS, TCL_TRACE_WRITES,
* TCL_TRACE_UNSETS, TCL_GLOBAL_ONLY, and
* TCL_NAMESPACE_ONLY. */
Tcl_VarTraceProc *proc, /* Function to call when specified ops are
* invoked upon varName. */
ClientData clientData) /* Arbitrary argument to pass to proc. */
{
return Tcl_TraceVar2(interp, varName, NULL, flags, proc, clientData);
}
/*
*----------------------------------------------------------------------
*
* Tcl_TraceVar2 --
*
* Arrange for reads and/or writes to a variable to cause a function to
* be invoked, which can monitor the operations and/or change their
* actions.
*
* Results:
* A standard Tcl return value.
*
* Side effects:
* A trace is set up on the variable given by part1 and part2, such that
* future references to the variable will be intermediated by proc. See
* the manual entry for complete details on the calling sequence for
* proc. The variable's flags are updated.
*
*----------------------------------------------------------------------
*/
int
Tcl_TraceVar2(
Tcl_Interp *interp, /* Interpreter in which variable is to be
* traced. */
const char *part1, /* Name of scalar variable or array. */
const char *part2, /* Name of element within array; NULL means
* trace applies to scalar variable or array
* as-a-whole. */
int flags, /* OR-ed collection of bits, including any of
* TCL_TRACE_READS, TCL_TRACE_WRITES,
* TCL_TRACE_UNSETS, TCL_GLOBAL_ONLY, and
* TCL_NAMESPACE_ONLY. */
Tcl_VarTraceProc *proc, /* Function to call when specified ops are
* invoked upon varName. */
ClientData clientData) /* Arbitrary argument to pass to proc. */
{
register VarTrace *tracePtr;
int result;
tracePtr = (VarTrace *) ckalloc(sizeof(VarTrace));
tracePtr->traceProc = proc;
tracePtr->clientData = clientData;
tracePtr->flags = flags;
result = TraceVarEx(interp, part1, part2, tracePtr);
if (result != TCL_OK) {
ckfree((char *) tracePtr);
}
return result;
}
/*
*----------------------------------------------------------------------
*
* TraceVarEx --
*
* Arrange for reads and/or writes to a variable to cause a function to
* be invoked, which can monitor the operations and/or change their
* actions.
*
* Results:
* A standard Tcl return value.
*
* Side effects:
* A trace is set up on the variable given by part1 and part2, such that
* future references to the variable will be intermediated by the
* traceProc listed in tracePtr. See the manual entry for complete
* details on the calling sequence for proc.
*
*----------------------------------------------------------------------
*/
static int
TraceVarEx(
Tcl_Interp *interp, /* Interpreter in which variable is to be
* traced. */
const char *part1, /* Name of scalar variable or array. */
const char *part2, /* Name of element within array; NULL means
* trace applies to scalar variable or array
* as-a-whole. */
register VarTrace *tracePtr)/* Structure containing flags, traceProc and
* clientData fields. Others should be left
* blank. Will be ckfree()d (eventually) if
* this function returns TCL_OK, and up to
* caller to free if this function returns
* TCL_ERROR. */
{
Interp *iPtr = (Interp *) interp;
Var *varPtr, *arrayPtr;
int flagMask, isNew;
Tcl_HashEntry *hPtr;
/*
* We strip 'flags' down to just the parts which are relevant to
* TclLookupVar, to avoid conflicts between trace flags and internal
* namespace flags such as 'TCL_FIND_ONLY_NS'. This can now occur since we
* have trace flags with values 0x1000 and higher.
*/
flagMask = TCL_GLOBAL_ONLY | TCL_NAMESPACE_ONLY;
varPtr = TclLookupVar(interp, part1, part2,
(tracePtr->flags & flagMask) | TCL_LEAVE_ERR_MSG,
"trace", /*createPart1*/ 1, /*createPart2*/ 1, &arrayPtr);
if (varPtr == NULL) {
return TCL_ERROR;
}
/*
* Check for a nonsense flag combination. Note that this is a Tcl_Panic()
* because there should be no code path that ever sets both flags.
*/
if ((tracePtr->flags&TCL_TRACE_RESULT_DYNAMIC)
&& (tracePtr->flags&TCL_TRACE_RESULT_OBJECT)) {
Tcl_Panic("bad result flag combination");
}
/*
* Set up trace information.
*/
flagMask = TCL_TRACE_READS | TCL_TRACE_WRITES | TCL_TRACE_UNSETS |
TCL_TRACE_ARRAY | TCL_TRACE_RESULT_DYNAMIC | TCL_TRACE_RESULT_OBJECT;
#ifndef TCL_REMOVE_OBSOLETE_TRACES
flagMask |= TCL_TRACE_OLD_STYLE;
#endif
tracePtr->flags = tracePtr->flags & flagMask;
hPtr = Tcl_CreateHashEntry(&iPtr->varTraces, (char *) varPtr, &isNew);
if (isNew) {
tracePtr->nextPtr = NULL;
} else {
tracePtr->nextPtr = (VarTrace *) Tcl_GetHashValue(hPtr);
}
Tcl_SetHashValue(hPtr, (char *) tracePtr);
/*
* Mark the variable as traced so we know to call them.
*/
varPtr->flags |= (tracePtr->flags & VAR_ALL_TRACES);
return TCL_OK;
}
/*
* Local Variables:
* mode: c
* c-basic-offset: 4
* fill-column: 78
* End:
*/
|
