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Diffstat (limited to 'generic/tclVar.c')
| -rw-r--r-- | generic/tclVar.c | 4552 |
1 files changed, 4552 insertions, 0 deletions
diff --git a/generic/tclVar.c b/generic/tclVar.c new file mode 100644 index 0000000..f013e65 --- /dev/null +++ b/generic/tclVar.c @@ -0,0 +1,4552 @@ +/* + * tclVar.c -- + * + * This file contains routines that implement Tcl variables + * (both scalars and arrays). + * + * The implementation of arrays is modelled after an initial + * implementation by Mark Diekhans and Karl Lehenbauer. + * + * Copyright (c) 1987-1994 The Regents of the University of California. + * Copyright (c) 1994-1997 Sun Microsystems, Inc. + * + * See the file "license.terms" for information on usage and redistribution + * of this file, and for a DISCLAIMER OF ALL WARRANTIES. + * + * SCCS: @(#) tclVar.c 1.130 97/10/29 18:26:16 + */ + +#include "tclInt.h" +#include "tclPort.h" + +/* + * The strings below are used to indicate what went wrong when a + * variable access is denied. + */ + +static char *noSuchVar = "no such variable"; +static char *isArray = "variable is array"; +static char *needArray = "variable isn't array"; +static char *noSuchElement = "no such element in array"; +static char *danglingUpvar = "upvar refers to element in deleted array"; +static char *badNamespace = "parent namespace doesn't exist"; +static char *missingName = "missing variable name"; + +/* + * Forward references to procedures defined later in this file: + */ + +static char * CallTraces _ANSI_ARGS_((Interp *iPtr, Var *arrayPtr, + Var *varPtr, char *part1, char *part2, + int flags)); +static void CleanupVar _ANSI_ARGS_((Var *varPtr, + Var *arrayPtr)); +static void DeleteSearches _ANSI_ARGS_((Var *arrayVarPtr)); +static void DeleteArray _ANSI_ARGS_((Interp *iPtr, + char *arrayName, Var *varPtr, int flags)); +static int MakeUpvar _ANSI_ARGS_(( + Interp *iPtr, CallFrame *framePtr, + char *otherP1, char *otherP2, int otherFlags, + char *myName, int myFlags)); +static Var * NewVar _ANSI_ARGS_((void)); +static ArraySearch * ParseSearchId _ANSI_ARGS_((Tcl_Interp *interp, + Var *varPtr, char *varName, char *string)); +static void VarErrMsg _ANSI_ARGS_((Tcl_Interp *interp, + char *part1, char *part2, char *operation, + char *reason)); + +/* + *---------------------------------------------------------------------- + * + * TclLookupVar -- + * + * This procedure is used by virtually all of the variable code to + * locate a variable given its name(s). + * + * Results: + * The return value is a pointer to the variable structure indicated by + * part1 and part2, or NULL if the variable couldn't be found. If the + * variable is found, *arrayPtrPtr is filled in with the address of the + * variable structure for the array that contains the variable (or NULL + * if the variable is a scalar). If the variable can't be found and + * either createPart1 or createPart2 are 1, a new as-yet-undefined + * (VAR_UNDEFINED) variable structure is created, entered into a hash + * table, and returned. + * + * If the variable isn't found and creation wasn't specified, or some + * other error occurs, NULL is returned and an error message is left in + * interp->result if TCL_LEAVE_ERR_MSG is set in flags. (The result + * isn't put in interp->objResultPtr because this procedure is used + * by so many string-based routines.) + * + * Note: it's possible for the variable returned to be VAR_UNDEFINED + * even if createPart1 or createPart2 are 1 (these only cause the hash + * table entry or array to be created). For example, the variable might + * be a global that has been unset but is still referenced by a + * procedure, or a variable that has been unset but it only being kept + * in existence (if VAR_UNDEFINED) by a trace. + * + * Side effects: + * New hashtable entries may be created if createPart1 or createPart2 + * are 1. + * + *---------------------------------------------------------------------- + */ + +Var * +TclLookupVar(interp, part1, part2, flags, msg, createPart1, createPart2, + arrayPtrPtr) + Tcl_Interp *interp; /* Interpreter to use for lookup. */ + char *part1; /* If part2 isn't NULL, this is the name of + * an array. Otherwise, if the + * TCL_PARSE_PART1 flag bit is set this + * is a full variable name that could + * include a parenthesized array elemnt. If + * TCL_PARSE_PART1 isn't present, then + * this is the name of a scalar variable. */ + char *part2; /* Name of element within array, or NULL. */ + int flags; /* Only TCL_GLOBAL_ONLY, TCL_NAMESPACE_ONLY, + * TCL_LEAVE_ERR_MSG, and + * TCL_PARSE_PART1 bits matter. */ + char *msg; /* Verb to use in error messages, e.g. + * "read" or "set". Only needed if + * TCL_LEAVE_ERR_MSG is set in flags. */ + int createPart1; /* If 1, create hash table entry for part 1 + * of name, if it doesn't already exist. If + * 0, return error if it doesn't exist. */ + int createPart2; /* If 1, create hash table entry for part 2 + * of name, if it doesn't already exist. If + * 0, return error if it doesn't exist. */ + Var **arrayPtrPtr; /* If the name refers to an element of an + * array, *arrayPtrPtr gets filled in with + * address of array variable. Otherwise + * this is set to NULL. */ +{ + Interp *iPtr = (Interp *) interp; + CallFrame *varFramePtr = iPtr->varFramePtr; + /* Points to the procedure call frame whose + * variables are currently in use. Same as + * the current procedure's frame, if any, + * unless an "uplevel" is executing. */ + Tcl_HashTable *tablePtr; /* Points to the hashtable, if any, in which + * to look up the variable. */ + Tcl_Var var; /* Used to search for global names. */ + Var *varPtr; /* Points to the Var structure returned for + * the variable. */ + char *elName; /* Name of array element or NULL; may be + * same as part2, or may be openParen+1. */ + char *openParen, *closeParen; + /* If this procedure parses a name into + * array and index, these point to the + * parens around the index. Otherwise they + * are NULL. These are needed to restore + * the parens after parsing the name. */ + Namespace *varNsPtr, *dummy1Ptr, *dummy2Ptr; + Tcl_HashEntry *hPtr; + register char *p; + int new, i, result; + + varPtr = NULL; + *arrayPtrPtr = NULL; + openParen = closeParen = NULL; + varNsPtr = NULL; /* set non-NULL if a nonlocal variable */ + + /* + * If the name hasn't been parsed into array name and index yet, + * do it now. + */ + + elName = part2; + if (flags & TCL_PARSE_PART1) { + for (p = part1; ; p++) { + if (*p == 0) { + elName = NULL; + break; + } + if (*p == '(') { + openParen = p; + do { + p++; + } while (*p != '\0'); + p--; + if (*p == ')') { + closeParen = p; + *openParen = 0; + elName = openParen+1; + } else { + openParen = NULL; + elName = NULL; + } + break; + } + } + } + + /* + * Look up part1. Look it up as either a namespace variable or as a + * local variable in a procedure call frame (varFramePtr). + * Interpret part1 as a namespace variable if: + * 1) so requested by a TCL_GLOBAL_ONLY or TCL_NAMESPACE_ONLY flag, + * 2) there is no active frame (we're at the global :: scope), + * 3) the active frame was pushed to define the namespace context + * for a "namespace eval" or "namespace inscope" command, + * 4) the name has namespace qualifiers ("::"s). + * Otherwise, if part1 is a local variable, search first in the + * frame's array of compiler-allocated local variables, then in its + * hashtable for runtime-created local variables. + * + * If createPart1 and the variable isn't found, create the variable and, + * if necessary, create varFramePtr's local var hashtable. + */ + + if (((flags & (TCL_GLOBAL_ONLY | TCL_NAMESPACE_ONLY)) != 0) + || (varFramePtr == NULL) + || !varFramePtr->isProcCallFrame + || (strstr(part1, "::") != NULL)) { + char *tail; + + var = Tcl_FindNamespaceVar(interp, part1, (Tcl_Namespace *) NULL, + flags); + if (var != (Tcl_Var) NULL) { + varPtr = (Var *) var; + } + if (varPtr == NULL) { + if (flags & TCL_LEAVE_ERR_MSG) { + Tcl_ResetResult(interp); + } + if (createPart1) { /* var wasn't found so create it */ + result = TclGetNamespaceForQualName(interp, part1, + (Namespace *) NULL, flags, &varNsPtr, &dummy1Ptr, + &dummy2Ptr, &tail); + if (result != TCL_OK) { + if (flags & TCL_LEAVE_ERR_MSG) { + /* + * Move the interpreter's object result to the + * string result, then reset the object result. + * FAILS IF OBJECT RESULT'S STRING REP HAS NULLS. + */ + + Tcl_SetResult(interp, + TclGetStringFromObj(Tcl_GetObjResult(interp), + (int *) NULL), + TCL_VOLATILE); + } + goto done; + } + if (varNsPtr == NULL) { + if (flags & TCL_LEAVE_ERR_MSG) { + VarErrMsg(interp, part1, part2, msg, badNamespace); + } + goto done; + } + if (tail == NULL) { + if (flags & TCL_LEAVE_ERR_MSG) { + VarErrMsg(interp, part1, part2, msg, missingName); + } + goto done; + } + hPtr = Tcl_CreateHashEntry(&varNsPtr->varTable, tail, &new); + varPtr = NewVar(); + Tcl_SetHashValue(hPtr, varPtr); + varPtr->hPtr = hPtr; + varPtr->nsPtr = varNsPtr; + } else { /* var wasn't found and not to create it */ + if (flags & TCL_LEAVE_ERR_MSG) { + VarErrMsg(interp, part1, part2, msg, noSuchVar); + } + goto done; + } + } + } else { /* local var: look in frame varFramePtr */ + Proc *procPtr = varFramePtr->procPtr; + int localCt = procPtr->numCompiledLocals; + CompiledLocal *localPtr = procPtr->firstLocalPtr; + Var *localVarPtr = varFramePtr->compiledLocals; + int part1Len = strlen(part1); + + for (i = 0; i < localCt; i++) { + if (!localPtr->isTemp) { + char *localName = localVarPtr->name; + if ((part1[0] == localName[0]) + && (part1Len == localPtr->nameLength) + && (strcmp(part1, localName) == 0)) { + varPtr = localVarPtr; + break; + } + } + localVarPtr++; + localPtr = localPtr->nextPtr; + } + if (varPtr == NULL) { /* look in the frame's var hash table */ + tablePtr = varFramePtr->varTablePtr; + if (createPart1) { + if (tablePtr == NULL) { + tablePtr = (Tcl_HashTable *) + ckalloc(sizeof(Tcl_HashTable)); + Tcl_InitHashTable(tablePtr, TCL_STRING_KEYS); + varFramePtr->varTablePtr = tablePtr; + } + hPtr = Tcl_CreateHashEntry(tablePtr, part1, &new); + if (new) { + varPtr = NewVar(); + Tcl_SetHashValue(hPtr, varPtr); + varPtr->hPtr = hPtr; + varPtr->nsPtr = NULL; /* a local variable */ + } else { + varPtr = (Var *) Tcl_GetHashValue(hPtr); + } + } else { + hPtr = NULL; + if (tablePtr != NULL) { + hPtr = Tcl_FindHashEntry(tablePtr, part1); + } + if (hPtr == NULL) { + if (flags & TCL_LEAVE_ERR_MSG) { + VarErrMsg(interp, part1, part2, msg, noSuchVar); + } + goto done; + } + varPtr = (Var *) Tcl_GetHashValue(hPtr); + } + } + } + if (openParen != NULL) { + *openParen = '('; + openParen = NULL; + } + + /* + * If varPtr is a link variable, we have a reference to some variable + * that was created through an "upvar" or "global" command. Traverse + * through any links until we find the referenced variable. + */ + + while (TclIsVarLink(varPtr)) { + varPtr = varPtr->value.linkPtr; + } + + /* + * If we're not dealing with an array element, return varPtr. + */ + + if (elName == NULL) { + goto done; + } + + /* + * We're dealing with an array element. Make sure the variable is an + * array and look up the element (create the element if desired). + */ + + if (TclIsVarUndefined(varPtr) && !TclIsVarArrayElement(varPtr)) { + if (!createPart1) { + if (flags & TCL_LEAVE_ERR_MSG) { + VarErrMsg(interp, part1, part2, msg, noSuchVar); + } + varPtr = NULL; + goto done; + } + TclSetVarArray(varPtr); + TclClearVarUndefined(varPtr); + varPtr->value.tablePtr = + (Tcl_HashTable *) ckalloc(sizeof(Tcl_HashTable)); + Tcl_InitHashTable(varPtr->value.tablePtr, TCL_STRING_KEYS); + } else if (!TclIsVarArray(varPtr)) { + if (flags & TCL_LEAVE_ERR_MSG) { + VarErrMsg(interp, part1, part2, msg, needArray); + } + varPtr = NULL; + goto done; + } + *arrayPtrPtr = varPtr; + if (closeParen != NULL) { + *closeParen = 0; + } + if (createPart2) { + hPtr = Tcl_CreateHashEntry(varPtr->value.tablePtr, elName, &new); + if (closeParen != NULL) { + *closeParen = ')'; + } + if (new) { + if (varPtr->searchPtr != NULL) { + DeleteSearches(varPtr); + } + varPtr = NewVar(); + Tcl_SetHashValue(hPtr, varPtr); + varPtr->hPtr = hPtr; + varPtr->nsPtr = varNsPtr; + TclSetVarArrayElement(varPtr); + } + } else { + hPtr = Tcl_FindHashEntry(varPtr->value.tablePtr, elName); + if (closeParen != NULL) { + *closeParen = ')'; + } + if (hPtr == NULL) { + if (flags & TCL_LEAVE_ERR_MSG) { + VarErrMsg(interp, part1, part2, msg, noSuchElement); + } + varPtr = NULL; + goto done; + } + } + varPtr = (Var *) Tcl_GetHashValue(hPtr); + + done: + if (openParen != NULL) { + *openParen = '('; + } + return varPtr; +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_GetVar -- + * + * Return the value of a Tcl variable as a string. + * + * Results: + * The return value points to the current value of varName as a string. + * If the variable is not defined or can't be read because of a clash + * in array usage then a NULL pointer is returned and an error message + * is left in interp->result if the TCL_LEAVE_ERR_MSG flag is set. + * Note: the return value is only valid up until the next change to the + * variable; if you depend on the value lasting longer than that, then + * make yourself a private copy. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +char * +Tcl_GetVar(interp, varName, flags) + Tcl_Interp *interp; /* Command interpreter in which varName is + * to be looked up. */ + char *varName; /* Name of a variable in interp. */ + int flags; /* OR-ed combination of TCL_GLOBAL_ONLY, + * TCL_NAMESPACE_ONLY or TCL_LEAVE_ERR_MSG + * bits. */ +{ + return Tcl_GetVar2(interp, varName, (char *) NULL, + (flags | TCL_PARSE_PART1)); +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_GetVar2 -- + * + * Return the value of a Tcl variable as a string, given a two-part + * name consisting of array name and element within array. + * + * Results: + * The return value points to the current value of the variable given + * by part1 and part2 as a string. If the specified variable doesn't + * exist, or if there is a clash in array usage, then NULL is returned + * and a message will be left in interp->result if the + * TCL_LEAVE_ERR_MSG flag is set. Note: the return value is only valid + * up until the next change to the variable; if you depend on the value + * lasting longer than that, then make yourself a private copy. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +char * +Tcl_GetVar2(interp, part1, part2, flags) + Tcl_Interp *interp; /* Command interpreter in which variable is + * to be looked up. */ + char *part1; /* Name of an array (if part2 is non-NULL) + * or the name of a variable. */ + char *part2; /* If non-NULL, gives the name of an element + * in the array part1. */ + int flags; /* OR-ed combination of TCL_GLOBAL_ONLY, + * TCL_NAMESPACE_ONLY, TCL_LEAVE_ERR_MSG, + * and TCL_PARSE_PART1 bits. */ +{ + register Tcl_Obj *part1Ptr; + register Tcl_Obj *part2Ptr = NULL; + Tcl_Obj *objPtr; + int length; + + length = strlen(part1); + TclNewObj(part1Ptr); + TclInitStringRep(part1Ptr, part1, length); + Tcl_IncrRefCount(part1Ptr); + + if (part2 != NULL) { + length = strlen(part2); + TclNewObj(part2Ptr); + TclInitStringRep(part2Ptr, part2, length); + Tcl_IncrRefCount(part2Ptr); + } + + objPtr = Tcl_ObjGetVar2(interp, part1Ptr, part2Ptr, flags); + + TclDecrRefCount(part1Ptr); /* done with the part1 name object */ + if (part2Ptr != NULL) { + TclDecrRefCount(part2Ptr); /* and the part2 name object */ + } + + if (objPtr == NULL) { + /* + * Move the interpreter's object result to the string result, + * then reset the object result. + * FAILS IF OBJECT RESULT'S STRING REPRESENTATION CONTAINS NULLS. + */ + + Tcl_SetResult(interp, + TclGetStringFromObj(Tcl_GetObjResult(interp), (int *) NULL), + TCL_VOLATILE); + return NULL; + } + + /* + * THIS FAILS IF Tcl_ObjGetVar2's RESULT'S STRING REP HAS A NULL BYTE. + */ + + return TclGetStringFromObj(objPtr, (int *) NULL); +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_ObjGetVar2 -- + * + * Return the value of a Tcl variable as a Tcl object, given a + * two-part name consisting of array name and element within array. + * + * Results: + * The return value points to the current object value of the variable + * given by part1Ptr and part2Ptr. If the specified variable doesn't + * exist, or if there is a clash in array usage, then NULL is returned + * and a message will be left in the interpreter's result if the + * TCL_LEAVE_ERR_MSG flag is set. + * + * Side effects: + * The ref count for the returned object is _not_ incremented to + * reflect the returned reference; if you want to keep a reference to + * the object you must increment its ref count yourself. + * + *---------------------------------------------------------------------- + */ + +Tcl_Obj * +Tcl_ObjGetVar2(interp, part1Ptr, part2Ptr, flags) + Tcl_Interp *interp; /* Command interpreter in which variable is + * to be looked up. */ + register Tcl_Obj *part1Ptr; /* Points to an object holding the name of + * an array (if part2 is non-NULL) or the + * name of a variable. */ + register Tcl_Obj *part2Ptr; /* If non-null, points to an object holding + * the name of an element in the array + * part1Ptr. */ + int flags; /* OR-ed combination of TCL_GLOBAL_ONLY, + * TCL_LEAVE_ERR_MSG, and + * TCL_PARSE_PART1 bits. */ +{ + Interp *iPtr = (Interp *) interp; + register Var *varPtr; + Var *arrayPtr; + char *part1, *msg; + char *part2 = NULL; + + /* + * THIS FAILS IF A NAME OBJECT'S STRING REP HAS A NULL BYTE. + */ + + part1 = TclGetStringFromObj(part1Ptr, (int *) NULL); + if (part2Ptr != NULL) { + part2 = TclGetStringFromObj(part2Ptr, (int *) NULL); + } + varPtr = TclLookupVar(interp, part1, part2, flags, "read", + /*createPart1*/ 0, /*createPart2*/ 1, &arrayPtr); + if (varPtr == NULL) { + return NULL; + } + + /* + * Invoke any traces that have been set for the variable. + */ + + if ((varPtr->tracePtr != NULL) + || ((arrayPtr != NULL) && (arrayPtr->tracePtr != NULL))) { + msg = CallTraces(iPtr, arrayPtr, varPtr, part1, part2, + (flags & (TCL_NAMESPACE_ONLY|TCL_GLOBAL_ONLY|TCL_PARSE_PART1)) | TCL_TRACE_READS); + if (msg != NULL) { + if (flags & TCL_LEAVE_ERR_MSG) { + VarErrMsg(interp, part1, part2, "read", msg); + } + goto errorReturn; + } + } + + /* + * Return the element if it's an existing scalar variable. + */ + + if (TclIsVarScalar(varPtr) && !TclIsVarUndefined(varPtr)) { + return varPtr->value.objPtr; + } + + if (flags & TCL_LEAVE_ERR_MSG) { + if (TclIsVarUndefined(varPtr) && (arrayPtr != NULL) + && !TclIsVarUndefined(arrayPtr)) { + msg = noSuchElement; + } else if (TclIsVarArray(varPtr)) { + msg = isArray; + } else { + msg = noSuchVar; + } + VarErrMsg(interp, part1, part2, "read", msg); + } + + /* + * An error. If the variable doesn't exist anymore and no-one's using + * it, then free up the relevant structures and hash table entries. + */ + + errorReturn: + if (TclIsVarUndefined(varPtr)) { + CleanupVar(varPtr, arrayPtr); + } + return NULL; +} + +/* + *---------------------------------------------------------------------- + * + * TclGetIndexedScalar -- + * + * Return the Tcl object value of a local scalar variable in the active + * procedure, given its index in the procedure's array of compiler + * allocated local variables. + * + * Results: + * The return value points to the current object value of the variable + * given by localIndex. If the specified variable doesn't exist, or + * there is a clash in array usage, or an error occurs while executing + * variable traces, then NULL is returned and a message will be left in + * the interpreter's result if leaveErrorMsg is 1. + * + * Side effects: + * The ref count for the returned object is _not_ incremented to + * reflect the returned reference; if you want to keep a reference to + * the object you must increment its ref count yourself. + * + *---------------------------------------------------------------------- + */ + +Tcl_Obj * +TclGetIndexedScalar(interp, localIndex, leaveErrorMsg) + Tcl_Interp *interp; /* Command interpreter in which variable is + * to be looked up. */ + int localIndex; /* Index of variable in procedure's array + * of local variables. */ + int leaveErrorMsg; /* 1 if to leave an error message in + * interpreter's result on an error. + * Otherwise no error message is left. */ +{ + Interp *iPtr = (Interp *) interp; + CallFrame *varFramePtr = iPtr->varFramePtr; + /* Points to the procedure call frame whose + * variables are currently in use. Same as + * the current procedure's frame, if any, + * unless an "uplevel" is executing. */ + Var *compiledLocals = varFramePtr->compiledLocals; + Var *varPtr; /* Points to the variable's in-frame Var + * structure. */ + char *varName; /* Name of the local variable. */ + char *msg; + +#ifdef TCL_COMPILE_DEBUG + Proc *procPtr = varFramePtr->procPtr; + int localCt = procPtr->numCompiledLocals; + + if (compiledLocals == NULL) { + fprintf(stderr, "\nTclGetIndexedScalar: can't get local %i in frame 0x%x, no compiled locals\n", + localIndex, (unsigned int) varFramePtr); + panic("TclGetIndexedScalar: no compiled locals in frame 0x%x", + (unsigned int) varFramePtr); + } + if ((localIndex < 0) || (localIndex >= localCt)) { + fprintf(stderr, "\nTclGetIndexedScalar: can't get local %i in frame 0x%x with %i locals\n", + localIndex, (unsigned int) varFramePtr, localCt); + panic("TclGetIndexedScalar: bad local index %i in frame 0x%x", + localIndex, (unsigned int) varFramePtr); + } +#endif /* TCL_COMPILE_DEBUG */ + + varPtr = &(compiledLocals[localIndex]); + varName = varPtr->name; + + /* + * If varPtr is a link variable, we have a reference to some variable + * that was created through an "upvar" or "global" command, or we have a + * reference to a variable in an enclosing namespace. Traverse through + * any links until we find the referenced variable. + */ + + while (TclIsVarLink(varPtr)) { + varPtr = varPtr->value.linkPtr; + } + + /* + * Invoke any traces that have been set for the variable. + */ + + if (varPtr->tracePtr != NULL) { + msg = CallTraces(iPtr, /*arrayPtr*/ NULL, varPtr, varName, NULL, + TCL_TRACE_READS); + if (msg != NULL) { + if (leaveErrorMsg) { + VarErrMsg(interp, varName, NULL, "read", msg); + } + return NULL; + } + } + + /* + * Make sure we're dealing with a scalar variable and not an array, and + * that the variable exists (isn't undefined). + */ + + if (!TclIsVarScalar(varPtr) || TclIsVarUndefined(varPtr)) { + if (leaveErrorMsg) { + if (TclIsVarArray(varPtr)) { + msg = isArray; + } else { + msg = noSuchVar; + } + VarErrMsg(interp, varName, NULL, "read", msg); + } + return NULL; + } + return varPtr->value.objPtr; +} + +/* + *---------------------------------------------------------------------- + * + * TclGetElementOfIndexedArray -- + * + * Return the Tcl object value for an element in a local array + * variable. The element is named by the object elemPtr while the + * array is specified by its index in the active procedure's array + * of compiler allocated local variables. + * + * Results: + * The return value points to the current object value of the + * element. If the specified array or element doesn't exist, or there + * is a clash in array usage, or an error occurs while executing + * variable traces, then NULL is returned and a message will be left in + * the interpreter's result if leaveErrorMsg is 1. + * + * Side effects: + * The ref count for the returned object is _not_ incremented to + * reflect the returned reference; if you want to keep a reference to + * the object you must increment its ref count yourself. + * + *---------------------------------------------------------------------- + */ + +Tcl_Obj * +TclGetElementOfIndexedArray(interp, localIndex, elemPtr, leaveErrorMsg) + Tcl_Interp *interp; /* Command interpreter in which variable is + * to be looked up. */ + int localIndex; /* Index of array variable in procedure's + * array of local variables. */ + Tcl_Obj *elemPtr; /* Points to an object holding the name of + * an element to get in the array. */ + int leaveErrorMsg; /* 1 if to leave an error message in + * the interpreter's result on an error. + * Otherwise no error message is left. */ +{ + Interp *iPtr = (Interp *) interp; + CallFrame *varFramePtr = iPtr->varFramePtr; + /* Points to the procedure call frame whose + * variables are currently in use. Same as + * the current procedure's frame, if any, + * unless an "uplevel" is executing. */ + Var *compiledLocals = varFramePtr->compiledLocals; + Var *arrayPtr; /* Points to the array's in-frame Var + * structure. */ + char *arrayName; /* Name of the local array. */ + Tcl_HashEntry *hPtr; + Var *varPtr = NULL; /* Points to the element's Var structure + * that we return. Initialized to avoid + * compiler warning. */ + char *elem, *msg; + int new; + +#ifdef TCL_COMPILE_DEBUG + Proc *procPtr = varFramePtr->procPtr; + int localCt = procPtr->numCompiledLocals; + + if (compiledLocals == NULL) { + fprintf(stderr, "\nTclGetElementOfIndexedArray: can't get element of local %i in frame 0x%x, no compiled locals\n", + localIndex, (unsigned int) varFramePtr); + panic("TclGetIndexedScalar: no compiled locals in frame 0x%x", + (unsigned int) varFramePtr); + } + if ((localIndex < 0) || (localIndex >= localCt)) { + fprintf(stderr, "\nTclGetIndexedScalar: can't get element of local %i in frame 0x%x with %i locals\n", + localIndex, (unsigned int) varFramePtr, localCt); + panic("TclGetElementOfIndexedArray: bad local index %i in frame 0x%x", + localIndex, (unsigned int) varFramePtr); + } +#endif /* TCL_COMPILE_DEBUG */ + + /* + * THIS FAILS IF THE ELEMENT NAME OBJECT'S STRING REP HAS A NULL BYTE. + */ + + elem = Tcl_GetStringFromObj(elemPtr, (int *) NULL); + arrayPtr = &(compiledLocals[localIndex]); + arrayName = arrayPtr->name; + + /* + * If arrayPtr is a link variable, we have a reference to some variable + * that was created through an "upvar" or "global" command, or we have a + * reference to a variable in an enclosing namespace. Traverse through + * any links until we find the referenced variable. + */ + + while (TclIsVarLink(arrayPtr)) { + arrayPtr = arrayPtr->value.linkPtr; + } + + /* + * Make sure we're dealing with an array and that the array variable + * exists (isn't undefined). + */ + + if (!TclIsVarArray(arrayPtr) || TclIsVarUndefined(arrayPtr)) { + if (leaveErrorMsg) { + VarErrMsg(interp, arrayName, elem, "read", noSuchVar); + } + goto errorReturn; + } + + /* + * Look up the element. Note that we must create the element (but leave + * it marked undefined) if it does not already exist. This allows a + * trace to create new array elements "on the fly" that did not exist + * before. A trace is always passed a variable for the array element. If + * the trace does not define the variable, it will be deleted below (at + * errorReturn) and an error returned. + */ + + hPtr = Tcl_CreateHashEntry(arrayPtr->value.tablePtr, elem, &new); + if (new) { + if (arrayPtr->searchPtr != NULL) { + DeleteSearches(arrayPtr); + } + varPtr = NewVar(); + Tcl_SetHashValue(hPtr, varPtr); + varPtr->hPtr = hPtr; + varPtr->nsPtr = varFramePtr->nsPtr; + TclSetVarArrayElement(varPtr); + } else { + varPtr = (Var *) Tcl_GetHashValue(hPtr); + } + + /* + * Invoke any traces that have been set for the element variable. + */ + + if ((varPtr->tracePtr != NULL) + || ((arrayPtr != NULL) && (arrayPtr->tracePtr != NULL))) { + msg = CallTraces(iPtr, arrayPtr, varPtr, arrayName, elem, + TCL_TRACE_READS); + if (msg != NULL) { + if (leaveErrorMsg) { + VarErrMsg(interp, arrayName, elem, "read", msg); + } + goto errorReturn; + } + } + + /* + * Return the element if it's an existing scalar variable. + */ + + if (TclIsVarScalar(varPtr) && !TclIsVarUndefined(varPtr)) { + return varPtr->value.objPtr; + } + + if (leaveErrorMsg) { + if (TclIsVarArray(varPtr)) { + msg = isArray; + } else { + msg = noSuchVar; + } + VarErrMsg(interp, arrayName, elem, "read", msg); + } + + /* + * An error. If the variable doesn't exist anymore and no-one's using + * it, then free up the relevant structures and hash table entries. + */ + + errorReturn: + if ((varPtr != NULL) && TclIsVarUndefined(varPtr)) { + CleanupVar(varPtr, NULL); /* the array is not in a hashtable */ + } + return NULL; +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_SetCmd -- + * + * This procedure is invoked to process the "set" Tcl command. + * See the user documentation for details on what it does. + * + * Results: + * A standard Tcl result value. + * + * Side effects: + * A variable's value may be changed. + * + *---------------------------------------------------------------------- + */ + + /* ARGSUSED */ +int +Tcl_SetCmd(dummy, interp, argc, argv) + ClientData dummy; /* Not used. */ + register Tcl_Interp *interp; /* Current interpreter. */ + int argc; /* Number of arguments. */ + char **argv; /* Argument strings. */ +{ + if (argc == 2) { + char *value; + + value = Tcl_GetVar2(interp, argv[1], (char *) NULL, + TCL_LEAVE_ERR_MSG|TCL_PARSE_PART1); + if (value == NULL) { + return TCL_ERROR; + } + Tcl_SetResult(interp, value, TCL_VOLATILE); + return TCL_OK; + } else if (argc == 3) { + char *result; + + result = Tcl_SetVar2(interp, argv[1], (char *) NULL, argv[2], + TCL_LEAVE_ERR_MSG|TCL_PARSE_PART1); + if (result == NULL) { + return TCL_ERROR; + } + Tcl_SetResult(interp, result, TCL_VOLATILE); + return TCL_OK; + } else { + Tcl_AppendResult(interp, "wrong # args: should be \"", + argv[0], " varName ?newValue?\"", (char *) NULL); + return TCL_ERROR; + } +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_SetVar -- + * + * Change the value of a variable. + * + * Results: + * Returns a pointer to the malloc'ed string which is the character + * representation of the variable's new value. The caller must not + * modify this string. If the write operation was disallowed then NULL + * is returned; if the TCL_LEAVE_ERR_MSG flag is set, then an + * explanatory message will be left in interp->result. Note that the + * returned string may not be the same as newValue; this is because + * variable traces may modify the variable's value. + * + * Side effects: + * If varName is defined as a local or global variable in interp, + * its value is changed to newValue. If varName isn't currently + * defined, then a new global variable by that name is created. + * + *---------------------------------------------------------------------- + */ + +char * +Tcl_SetVar(interp, varName, newValue, flags) + Tcl_Interp *interp; /* Command interpreter in which varName is + * to be looked up. */ + char *varName; /* Name of a variable in interp. */ + char *newValue; /* New value for varName. */ + int flags; /* Various flags that tell how to set value: + * any of TCL_GLOBAL_ONLY, + * TCL_NAMESPACE_ONLY, TCL_APPEND_VALUE, + * TCL_LIST_ELEMENT, TCL_LEAVE_ERR_MSG. */ +{ + return Tcl_SetVar2(interp, varName, (char *) NULL, newValue, + (flags | TCL_PARSE_PART1)); +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_SetVar2 -- + * + * Given a two-part variable name, which may refer either to a + * scalar variable or an element of an array, change the value + * of the variable. If the named scalar or array or element + * doesn't exist then create one. + * + * Results: + * Returns a pointer to the malloc'ed string which is the character + * representation of the variable's new value. The caller must not + * modify this string. If the write operation was disallowed because an + * array was expected but not found (or vice versa), then NULL is + * returned; if the TCL_LEAVE_ERR_MSG flag is set, then an explanatory + * message will be left in interp->result. Note that the returned + * string may not be the same as newValue; this is because variable + * traces may modify the variable's value. + * + * Side effects: + * The value of the given variable is set. If either the array + * or the entry didn't exist then a new one is created. + * + *---------------------------------------------------------------------- + */ + +char * +Tcl_SetVar2(interp, part1, part2, newValue, flags) + Tcl_Interp *interp; /* Command interpreter in which variable is + * to be looked up. */ + char *part1; /* If part2 is NULL, this is name of scalar + * variable. Otherwise it is the name of + * an array. */ + char *part2; /* Name of an element within an array, or + * NULL. */ + char *newValue; /* New value for variable. */ + int flags; /* Various flags that tell how to set value: + * any of TCL_GLOBAL_ONLY, + * TCL_NAMESPACE_ONLY, TCL_APPEND_VALUE, + * TCL_LIST_ELEMENT, TCL_LEAVE_ERR_MSG, or + * TCL_PARSE_PART1. */ +{ + register Tcl_Obj *valuePtr; + register Tcl_Obj *part1Ptr; + register Tcl_Obj *part2Ptr = NULL; + Tcl_Obj *varValuePtr; + int length; + + /* + * Create an object holding the variable's new value and use + * Tcl_ObjSetVar2 to actually set the variable. + */ + + length = newValue ? strlen(newValue) : 0; + TclNewObj(valuePtr); + TclInitStringRep(valuePtr, newValue, length); + Tcl_IncrRefCount(valuePtr); + + length = strlen(part1) ; + TclNewObj(part1Ptr); + TclInitStringRep(part1Ptr, part1, length); + Tcl_IncrRefCount(part1Ptr); + + if (part2 != NULL) { + length = strlen(part2); + TclNewObj(part2Ptr); + TclInitStringRep(part2Ptr, part2, length); + Tcl_IncrRefCount(part2Ptr); + } + + varValuePtr = Tcl_ObjSetVar2(interp, part1Ptr, part2Ptr, valuePtr, + flags); + + TclDecrRefCount(part1Ptr); /* done with the part1 name object */ + if (part2Ptr != NULL) { + TclDecrRefCount(part2Ptr); /* and the part2 name object */ + } + Tcl_DecrRefCount(valuePtr); /* done with the object */ + + if (varValuePtr == NULL) { + /* + * Move the interpreter's object result to the string result, + * then reset the object result. + * FAILS IF OBJECT RESULT'S STRING REPRESENTATION CONTAINS NULLS. + */ + + Tcl_SetResult(interp, + TclGetStringFromObj(Tcl_GetObjResult(interp), (int *) NULL), + TCL_VOLATILE); + return NULL; + } + + /* + * THIS FAILS IF Tcl_ObjSetVar2's RESULT'S STRING REP HAS A NULL BYTE. + */ + + return TclGetStringFromObj(varValuePtr, (int *) NULL); +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_ObjSetVar2 -- + * + * Given a two-part variable name, which may refer either to a scalar + * variable or an element of an array, change the value of the variable + * to a new Tcl object value. If the named scalar or array or element + * doesn't exist then create one. + * + * Results: + * Returns a pointer to the Tcl_Obj holding the new value of the + * variable. If the write operation was disallowed because an array was + * expected but not found (or vice versa), then NULL is returned; if + * the TCL_LEAVE_ERR_MSG flag is set, then an explanatory message will + * be left in the interpreter's result. Note that the returned object + * may not be the same one referenced by newValuePtr; this is because + * variable traces may modify the variable's value. + * + * Side effects: + * The value of the given variable is set. If either the array or the + * entry didn't exist then a new variable is created. + * + * The reference count is decremented for any old value of the variable + * and incremented for its new value. If the new value for the variable + * is not the same one referenced by newValuePtr (perhaps as a result + * of a variable trace), then newValuePtr's ref count is left unchanged + * by Tcl_ObjSetVar2. newValuePtr's ref count is also left unchanged if + * we are appending it as a string value: that is, if "flags" includes + * TCL_APPEND_VALUE but not TCL_LIST_ELEMENT. + * + * The reference count for the returned object is _not_ incremented: if + * you want to keep a reference to the object you must increment its + * ref count yourself. + * + *---------------------------------------------------------------------- + */ + +Tcl_Obj * +Tcl_ObjSetVar2(interp, part1Ptr, part2Ptr, newValuePtr, flags) + Tcl_Interp *interp; /* Command interpreter in which variable is + * to be found. */ + register Tcl_Obj *part1Ptr; /* Points to an object holding the name of + * an array (if part2 is non-NULL) or the + * name of a variable. */ + register Tcl_Obj *part2Ptr; /* If non-null, points to an object holding + * the name of an element in the array + * part1Ptr. */ + Tcl_Obj *newValuePtr; /* New value for variable. */ + int flags; /* Various flags that tell how to set value: + * any of TCL_GLOBAL_ONLY, + * TCL_NAMESPACE_ONLY, TCL_APPEND_VALUE, + * TCL_LIST_ELEMENT, TCL_LEAVE_ERR_MSG, or + * TCL_PARSE_PART1. */ +{ + Interp *iPtr = (Interp *) interp; + register Var *varPtr; + Var *arrayPtr; + Tcl_Obj *oldValuePtr; + Tcl_Obj *resultPtr = NULL; + char *part1, *bytes; + char *part2 = NULL; + int length, result; + + /* + * THIS FAILS IF A NAME OBJECT'S STRING REP HAS A NULL BYTE. + */ + + part1 = TclGetStringFromObj(part1Ptr, (int *) NULL); + if (part2Ptr != NULL) { + part2 = TclGetStringFromObj(part2Ptr, (int *) NULL); + } + + varPtr = TclLookupVar(interp, part1, part2, flags, "set", + /*createPart1*/ 1, /*createPart2*/ 1, &arrayPtr); + if (varPtr == NULL) { + return NULL; + } + + /* + * If the variable is in a hashtable and its hPtr field is NULL, then we + * have an upvar to an array element where the array was deleted, + * leaving the element dangling at the end of the upvar. Generate an + * error (allowing the variable to be reset would screw up our storage + * allocation and is meaningless anyway). + */ + + if ((varPtr->flags & VAR_IN_HASHTABLE) && (varPtr->hPtr == NULL)) { + if (flags & TCL_LEAVE_ERR_MSG) { + VarErrMsg(interp, part1, part2, "set", danglingUpvar); + } + return NULL; + } + + /* + * It's an error to try to set an array variable itself. + */ + + if (TclIsVarArray(varPtr) && !TclIsVarUndefined(varPtr)) { + if (flags & TCL_LEAVE_ERR_MSG) { + VarErrMsg(interp, part1, part2, "set", isArray); + } + return NULL; + } + + /* + * At this point, if we were appending, we used to call read traces: we + * treated append as a read-modify-write. However, it seemed unlikely to + * us that a real program would be interested in such reads being done + * during a set operation. + */ + + /* + * Set the variable's new value. If appending, append the new value to + * the variable, either as a list element or as a string. Also, if + * appending, then if the variable's old value is unshared we can modify + * it directly, otherwise we must create a new copy to modify: this is + * "copy on write". + */ + + oldValuePtr = varPtr->value.objPtr; + if (flags & TCL_APPEND_VALUE) { + if (TclIsVarUndefined(varPtr) && (oldValuePtr != NULL)) { + Tcl_DecrRefCount(oldValuePtr); /* discard old value */ + varPtr->value.objPtr = NULL; + oldValuePtr = NULL; + } + if (flags & TCL_LIST_ELEMENT) { /* append list element */ + if (oldValuePtr == NULL) { + TclNewObj(oldValuePtr); + varPtr->value.objPtr = oldValuePtr; + Tcl_IncrRefCount(oldValuePtr); /* since var is reference */ + } else if (Tcl_IsShared(oldValuePtr)) { + varPtr->value.objPtr = Tcl_DuplicateObj(oldValuePtr); + Tcl_DecrRefCount(oldValuePtr); + oldValuePtr = varPtr->value.objPtr; + Tcl_IncrRefCount(oldValuePtr); /* since var is reference */ + } + result = Tcl_ListObjAppendElement(interp, oldValuePtr, + newValuePtr); + if (result != TCL_OK) { + return NULL; + } + } else { /* append string */ + /* + * We append newValuePtr's bytes but don't change its ref count. + */ + + bytes = Tcl_GetStringFromObj(newValuePtr, &length); + if (oldValuePtr == NULL) { + varPtr->value.objPtr = Tcl_NewStringObj(bytes, length); + Tcl_IncrRefCount(varPtr->value.objPtr); + } else { + if (Tcl_IsShared(oldValuePtr)) { /* append to copy */ + varPtr->value.objPtr = Tcl_DuplicateObj(oldValuePtr); + TclDecrRefCount(oldValuePtr); + oldValuePtr = varPtr->value.objPtr; + Tcl_IncrRefCount(oldValuePtr); /* since var is ref */ + } + Tcl_AppendToObj(oldValuePtr, bytes, length); + } + } + } else { + if (flags & TCL_LIST_ELEMENT) { /* set var to list element */ + int neededBytes, listFlags; + + /* + * We set the variable to the result of converting newValuePtr's + * string rep to a list element. We do not change newValuePtr's + * ref count. + */ + + if (oldValuePtr != NULL) { + Tcl_DecrRefCount(oldValuePtr); /* discard old value */ + } + bytes = Tcl_GetStringFromObj(newValuePtr, &length); + neededBytes = Tcl_ScanElement(bytes, &listFlags); + oldValuePtr = Tcl_NewObj(); + oldValuePtr->bytes = (char *) + ckalloc((unsigned) (neededBytes + 1)); + oldValuePtr->length = Tcl_ConvertElement(bytes, + oldValuePtr->bytes, listFlags); + varPtr->value.objPtr = oldValuePtr; + Tcl_IncrRefCount(varPtr->value.objPtr); + } else if (newValuePtr != oldValuePtr) { + varPtr->value.objPtr = newValuePtr; + Tcl_IncrRefCount(newValuePtr); /* var is another ref */ + if (oldValuePtr != NULL) { + TclDecrRefCount(oldValuePtr); /* discard old value */ + } + } + } + TclSetVarScalar(varPtr); + TclClearVarUndefined(varPtr); + if (arrayPtr != NULL) { + TclClearVarUndefined(arrayPtr); + } + + /* + * Invoke any write traces for the variable. + */ + + if ((varPtr->tracePtr != NULL) + || ((arrayPtr != NULL) && (arrayPtr->tracePtr != NULL))) { + char *msg = CallTraces(iPtr, arrayPtr, varPtr, part1, part2, + (flags & (TCL_GLOBAL_ONLY|TCL_NAMESPACE_ONLY|TCL_PARSE_PART1)) | TCL_TRACE_WRITES); + if (msg != NULL) { + if (flags & TCL_LEAVE_ERR_MSG) { + VarErrMsg(interp, part1, part2, "set", msg); + } + goto cleanup; + } + } + + /* + * Return the variable's value unless the variable was changed in some + * gross way by a trace (e.g. it was unset and then recreated as an + * array). + */ + + if (TclIsVarScalar(varPtr) && !TclIsVarUndefined(varPtr)) { + return varPtr->value.objPtr; + } + + /* + * A trace changed the value in some gross way. Return an empty string + * object. + */ + + resultPtr = iPtr->emptyObjPtr; + + /* + * If the variable doesn't exist anymore and no-one's using it, then + * free up the relevant structures and hash table entries. + */ + + cleanup: + if (TclIsVarUndefined(varPtr)) { + CleanupVar(varPtr, arrayPtr); + } + return resultPtr; +} + +/* + *---------------------------------------------------------------------- + * + * TclSetIndexedScalar -- + * + * Change the Tcl object value of a local scalar variable in the active + * procedure, given its compile-time allocated index in the procedure's + * array of local variables. + * + * Results: + * Returns a pointer to the Tcl_Obj holding the new value of the + * variable given by localIndex. If the specified variable doesn't + * exist, or there is a clash in array usage, or an error occurs while + * executing variable traces, then NULL is returned and a message will + * be left in the interpreter's result if leaveErrorMsg is 1. Note + * that the returned object may not be the same one referenced by + * newValuePtr; this is because variable traces may modify the + * variable's value. + * + * Side effects: + * The value of the given variable is set. The reference count is + * decremented for any old value of the variable and incremented for + * its new value. If as a result of a variable trace the new value for + * the variable is not the same one referenced by newValuePtr, then + * newValuePtr's ref count is left unchanged. The ref count for the + * returned object is _not_ incremented to reflect the returned + * reference; if you want to keep a reference to the object you must + * increment its ref count yourself. This procedure does not create + * new variables, but only sets those recognized at compile time. + * + *---------------------------------------------------------------------- + */ + +Tcl_Obj * +TclSetIndexedScalar(interp, localIndex, newValuePtr, leaveErrorMsg) + Tcl_Interp *interp; /* Command interpreter in which variable is + * to be found. */ + int localIndex; /* Index of variable in procedure's array + * of local variables. */ + Tcl_Obj *newValuePtr; /* New value for variable. */ + int leaveErrorMsg; /* 1 if to leave an error message in + * the interpreter's result on an error. + * Otherwise no error message is left. */ +{ + Interp *iPtr = (Interp *) interp; + CallFrame *varFramePtr = iPtr->varFramePtr; + /* Points to the procedure call frame whose + * variables are currently in use. Same as + * the current procedure's frame, if any, + * unless an "uplevel" is executing. */ + Var *compiledLocals = varFramePtr->compiledLocals; + register Var *varPtr; /* Points to the variable's in-frame Var + * structure. */ + char *varName; /* Name of the local variable. */ + Tcl_Obj *oldValuePtr; + Tcl_Obj *resultPtr = NULL; + +#ifdef TCL_COMPILE_DEBUG + Proc *procPtr = varFramePtr->procPtr; + int localCt = procPtr->numCompiledLocals; + + if (compiledLocals == NULL) { + fprintf(stderr, "\nTclSetIndexedScalar: can't set local %i in frame 0x%x, no compiled locals\n", + localIndex, (unsigned int) varFramePtr); + panic("TclSetIndexedScalar: no compiled locals in frame 0x%x", + (unsigned int) varFramePtr); + } + if ((localIndex < 0) || (localIndex >= localCt)) { + fprintf(stderr, "\nTclSetIndexedScalar: can't set local %i in frame 0x%x with %i locals\n", + localIndex, (unsigned int) varFramePtr, localCt); + panic("TclSetIndexedScalar: bad local index %i in frame 0x%x", + localIndex, (unsigned int) varFramePtr); + } +#endif /* TCL_COMPILE_DEBUG */ + + varPtr = &(compiledLocals[localIndex]); + varName = varPtr->name; + + /* + * If varPtr is a link variable, we have a reference to some variable + * that was created through an "upvar" or "global" command, or we have a + * reference to a variable in an enclosing namespace. Traverse through + * any links until we find the referenced variable. + */ + + while (TclIsVarLink(varPtr)) { + varPtr = varPtr->value.linkPtr; + } + + /* + * If the variable is in a hashtable and its hPtr field is NULL, then we + * have an upvar to an array element where the array was deleted, + * leaving the element dangling at the end of the upvar. Generate an + * error (allowing the variable to be reset would screw up our storage + * allocation and is meaningless anyway). + */ + + if ((varPtr->flags & VAR_IN_HASHTABLE) && (varPtr->hPtr == NULL)) { + if (leaveErrorMsg) { + VarErrMsg(interp, varName, NULL, "set", danglingUpvar); + } + return NULL; + } + + /* + * It's an error to try to set an array variable itself. + */ + + if (TclIsVarArray(varPtr) && !TclIsVarUndefined(varPtr)) { + if (leaveErrorMsg) { + VarErrMsg(interp, varName, NULL, "set", isArray); + } + return NULL; + } + + /* + * Set the variable's new value and discard its old value. We don't + * append with this "set" procedure so the old value isn't needed. + */ + + oldValuePtr = varPtr->value.objPtr; + if (newValuePtr != oldValuePtr) { /* set new value */ + varPtr->value.objPtr = newValuePtr; + Tcl_IncrRefCount(newValuePtr); /* var is another ref to obj */ + if (oldValuePtr != NULL) { + TclDecrRefCount(oldValuePtr); /* discard old value */ + } + } + TclSetVarScalar(varPtr); + TclClearVarUndefined(varPtr); + + /* + * Invoke any write traces for the variable. + */ + + if (varPtr->tracePtr != NULL) { + char *msg = CallTraces(iPtr, /*arrayPtr*/ NULL, varPtr, + varName, (char *) NULL, TCL_TRACE_WRITES); + if (msg != NULL) { + if (leaveErrorMsg) { + VarErrMsg(interp, varName, NULL, "set", msg); + } + goto cleanup; + } + } + + /* + * Return the variable's value unless the variable was changed in some + * gross way by a trace (e.g. it was unset and then recreated as an + * array). If it was changed is a gross way, just return an empty string + * object. + */ + + if (TclIsVarScalar(varPtr) && !TclIsVarUndefined(varPtr)) { + return varPtr->value.objPtr; + } + + resultPtr = Tcl_NewObj(); + + /* + * If the variable doesn't exist anymore and no-one's using it, then + * free up the relevant structures and hash table entries. + */ + + cleanup: + if (TclIsVarUndefined(varPtr)) { + CleanupVar(varPtr, NULL); + } + return resultPtr; +} + +/* + *---------------------------------------------------------------------- + * + * TclSetElementOfIndexedArray -- + * + * Change the Tcl object value of an element in a local array + * variable. The element is named by the object elemPtr while the array + * is specified by its index in the active procedure's array of + * compiler allocated local variables. + * + * Results: + * Returns a pointer to the Tcl_Obj holding the new value of the + * element. If the specified array or element doesn't exist, or there + * is a clash in array usage, or an error occurs while executing + * variable traces, then NULL is returned and a message will be left in + * the interpreter's result if leaveErrorMsg is 1. Note that the + * returned object may not be the same one referenced by newValuePtr; + * this is because variable traces may modify the variable's value. + * + * Side effects: + * The value of the given array element is set. The reference count is + * decremented for any old value of the element and incremented for its + * new value. If as a result of a variable trace the new value for the + * element is not the same one referenced by newValuePtr, then + * newValuePtr's ref count is left unchanged. The ref count for the + * returned object is _not_ incremented to reflect the returned + * reference; if you want to keep a reference to the object you must + * increment its ref count yourself. This procedure will not create new + * array variables, but only sets elements of those arrays recognized + * at compile time. However, if the entry doesn't exist then a new + * variable is created. + * + *---------------------------------------------------------------------- + */ + +Tcl_Obj * +TclSetElementOfIndexedArray(interp, localIndex, elemPtr, newValuePtr, + leaveErrorMsg) + Tcl_Interp *interp; /* Command interpreter in which the array is + * to be found. */ + int localIndex; /* Index of array variable in procedure's + * array of local variables. */ + Tcl_Obj *elemPtr; /* Points to an object holding the name of + * an element to set in the array. */ + Tcl_Obj *newValuePtr; /* New value for variable. */ + int leaveErrorMsg; /* 1 if to leave an error message in + * the interpreter's result on an error. + * Otherwise no error message is left. */ +{ + Interp *iPtr = (Interp *) interp; + CallFrame *varFramePtr = iPtr->varFramePtr; + /* Points to the procedure call frame whose + * variables are currently in use. Same as + * the current procedure's frame, if any, + * unless an "uplevel" is executing. */ + Var *compiledLocals = varFramePtr->compiledLocals; + Var *arrayPtr; /* Points to the array's in-frame Var + * structure. */ + char *arrayName; /* Name of the local array. */ + char *elem; + Tcl_HashEntry *hPtr; + Var *varPtr = NULL; /* Points to the element's Var structure + * that we return. */ + Tcl_Obj *resultPtr = NULL; + Tcl_Obj *oldValuePtr; + int new; + +#ifdef TCL_COMPILE_DEBUG + Proc *procPtr = varFramePtr->procPtr; + int localCt = procPtr->numCompiledLocals; + + if (compiledLocals == NULL) { + fprintf(stderr, "\nTclSetElementOfIndexedArray: can't set element of local %i in frame 0x%x, no compiled locals\n", + localIndex, (unsigned int) varFramePtr); + panic("TclSetIndexedScalar: no compiled locals in frame 0x%x", + (unsigned int) varFramePtr); + } + if ((localIndex < 0) || (localIndex >= localCt)) { + fprintf(stderr, "\nTclSetIndexedScalar: can't set elememt of local %i in frame 0x%x with %i locals\n", + localIndex, (unsigned int) varFramePtr, localCt); + panic("TclSetElementOfIndexedArray: bad local index %i in frame 0x%x", + localIndex, (unsigned int) varFramePtr); + } +#endif /* TCL_COMPILE_DEBUG */ + + /* + * THIS FAILS IF THE ELEMENT NAME OBJECT'S STRING REP HAS A NULL BYTE. + */ + + elem = Tcl_GetStringFromObj(elemPtr, (int *) NULL); + arrayPtr = &(compiledLocals[localIndex]); + arrayName = arrayPtr->name; + + /* + * If arrayPtr is a link variable, we have a reference to some variable + * that was created through an "upvar" or "global" command, or we have a + * reference to a variable in an enclosing namespace. Traverse through + * any links until we find the referenced variable. + */ + + while (TclIsVarLink(arrayPtr)) { + arrayPtr = arrayPtr->value.linkPtr; + } + + /* + * Make sure we're dealing with an array. + */ + + if (TclIsVarUndefined(arrayPtr) && !TclIsVarArrayElement(arrayPtr)) { + TclSetVarArray(arrayPtr); + arrayPtr->value.tablePtr = + (Tcl_HashTable *) ckalloc(sizeof(Tcl_HashTable)); + Tcl_InitHashTable(arrayPtr->value.tablePtr, TCL_STRING_KEYS); + TclClearVarUndefined(arrayPtr); + } else if (!TclIsVarArray(arrayPtr)) { + if (leaveErrorMsg) { + VarErrMsg(interp, arrayName, elem, "set", needArray); + } + goto errorReturn; + } + + /* + * Look up the element. + */ + + hPtr = Tcl_CreateHashEntry(arrayPtr->value.tablePtr, elem, &new); + if (new) { + if (arrayPtr->searchPtr != NULL) { + DeleteSearches(arrayPtr); + } + varPtr = NewVar(); + Tcl_SetHashValue(hPtr, varPtr); + varPtr->hPtr = hPtr; + varPtr->nsPtr = varFramePtr->nsPtr; + TclSetVarArrayElement(varPtr); + } + varPtr = (Var *) Tcl_GetHashValue(hPtr); + + /* + * It's an error to try to set an array variable itself. + */ + + if (TclIsVarArray(varPtr)) { + if (leaveErrorMsg) { + VarErrMsg(interp, arrayName, elem, "set", isArray); + } + goto errorReturn; + } + + /* + * Set the variable's new value and discard the old one. We don't + * append with this "set" procedure so the old value isn't needed. + */ + + oldValuePtr = varPtr->value.objPtr; + if (newValuePtr != oldValuePtr) { /* set new value */ + varPtr->value.objPtr = newValuePtr; + Tcl_IncrRefCount(newValuePtr); /* var is another ref to obj */ + if (oldValuePtr != NULL) { + TclDecrRefCount(oldValuePtr); /* discard old value */ + } + } + TclSetVarScalar(varPtr); + TclClearVarUndefined(varPtr); + + /* + * Invoke any write traces for the element variable. + */ + + if ((varPtr->tracePtr != NULL) + || ((arrayPtr != NULL) && (arrayPtr->tracePtr != NULL))) { + char *msg = CallTraces(iPtr, arrayPtr, varPtr, arrayName, elem, + TCL_TRACE_WRITES); + if (msg != NULL) { + if (leaveErrorMsg) { + VarErrMsg(interp, arrayName, elem, "set", msg); + } + goto errorReturn; + } + } + + /* + * Return the element's value unless it was changed in some gross way by + * a trace (e.g. it was unset and then recreated as an array). If it was + * changed is a gross way, just return an empty string object. + */ + + if (TclIsVarScalar(varPtr) && !TclIsVarUndefined(varPtr)) { + return varPtr->value.objPtr; + } + + resultPtr = Tcl_NewObj(); + + /* + * An error. If the variable doesn't exist anymore and no-one's using + * it, then free up the relevant structures and hash table entries. + */ + + errorReturn: + if (varPtr != NULL) { + if (TclIsVarUndefined(varPtr)) { + CleanupVar(varPtr, NULL); /* note: array isn't in hashtable */ + } + } + return resultPtr; +} + +/* + *---------------------------------------------------------------------- + * + * TclIncrVar2 -- + * + * Given a two-part variable name, which may refer either to a scalar + * variable or an element of an array, increment the Tcl object value + * of the variable by a specified amount. + * + * Results: + * Returns a pointer to the Tcl_Obj holding the new value of the + * variable. If the specified variable doesn't exist, or there is a + * clash in array usage, or an error occurs while executing variable + * traces, then NULL is returned and a message will be left in + * the interpreter's result. + * + * Side effects: + * The value of the given variable is incremented by the specified + * amount. If either the array or the entry didn't exist then a new + * variable is created. The ref count for the returned object is _not_ + * incremented to reflect the returned reference; if you want to keep a + * reference to the object you must increment its ref count yourself. + * + *---------------------------------------------------------------------- + */ + +Tcl_Obj * +TclIncrVar2(interp, part1Ptr, part2Ptr, incrAmount, part1NotParsed) + Tcl_Interp *interp; /* Command interpreter in which variable is + * to be found. */ + Tcl_Obj *part1Ptr; /* Points to an object holding the name of + * an array (if part2 is non-NULL) or the + * name of a variable. */ + Tcl_Obj *part2Ptr; /* If non-null, points to an object holding + * the name of an element in the array + * part1Ptr. */ + long incrAmount; /* Amount to be added to variable. */ + int part1NotParsed; /* 1 if part1 hasn't yet been parsed into + * an array name and index (if any). */ +{ + register Tcl_Obj *varValuePtr; + Tcl_Obj *resultPtr; + int createdNewObj; /* Set 1 if var's value object is shared + * so we must increment a copy (i.e. copy + * on write). */ + long i; + int flags, result; + + flags = TCL_LEAVE_ERR_MSG; + if (part1NotParsed) { + flags |= TCL_PARSE_PART1; + } + + varValuePtr = Tcl_ObjGetVar2(interp, part1Ptr, part2Ptr, flags); + if (varValuePtr == NULL) { + Tcl_AddObjErrorInfo(interp, + "\n (reading value of variable to increment)", -1); + return NULL; + } + + /* + * Increment the variable's value. If the object is unshared we can + * modify it directly, otherwise we must create a new copy to modify: + * this is "copy on write". Then free the variable's old string + * representation, if any, since it will no longer be valid. + */ + + createdNewObj = 0; + if (Tcl_IsShared(varValuePtr)) { + varValuePtr = Tcl_DuplicateObj(varValuePtr); + createdNewObj = 1; + } + result = Tcl_GetLongFromObj(interp, varValuePtr, &i); + if (result != TCL_OK) { + if (createdNewObj) { + Tcl_DecrRefCount(varValuePtr); /* free unneeded copy */ + } + return NULL; + } + Tcl_SetLongObj(varValuePtr, (i + incrAmount)); + + /* + * Store the variable's new value and run any write traces. + */ + + resultPtr = Tcl_ObjSetVar2(interp, part1Ptr, part2Ptr, varValuePtr, + flags); + if (resultPtr == NULL) { + return NULL; + } + return resultPtr; +} + +/* + *---------------------------------------------------------------------- + * + * TclIncrIndexedScalar -- + * + * Increments the Tcl object value of a local scalar variable in the + * active procedure, given its compile-time allocated index in the + * procedure's array of local variables. + * + * Results: + * Returns a pointer to the Tcl_Obj holding the new value of the + * variable given by localIndex. If the specified variable doesn't + * exist, or there is a clash in array usage, or an error occurs while + * executing variable traces, then NULL is returned and a message will + * be left in the interpreter's result. + * + * Side effects: + * The value of the given variable is incremented by the specified + * amount. The ref count for the returned object is _not_ incremented + * to reflect the returned reference; if you want to keep a reference + * to the object you must increment its ref count yourself. + * + *---------------------------------------------------------------------- + */ + +Tcl_Obj * +TclIncrIndexedScalar(interp, localIndex, incrAmount) + Tcl_Interp *interp; /* Command interpreter in which variable is + * to be found. */ + int localIndex; /* Index of variable in procedure's array + * of local variables. */ + long incrAmount; /* Amount to be added to variable. */ +{ + register Tcl_Obj *varValuePtr; + Tcl_Obj *resultPtr; + int createdNewObj; /* Set 1 if var's value object is shared + * so we must increment a copy (i.e. copy + * on write). */ + long i; + int result; + + varValuePtr = TclGetIndexedScalar(interp, localIndex, + /*leaveErrorMsg*/ 1); + if (varValuePtr == NULL) { + Tcl_AddObjErrorInfo(interp, + "\n (reading value of variable to increment)", -1); + return NULL; + } + + /* + * Reach into the object's representation to extract and increment the + * variable's value. If the object is unshared we can modify it + * directly, otherwise we must create a new copy to modify: this is + * "copy on write". Then free the variable's old string representation, + * if any, since it will no longer be valid. + */ + + createdNewObj = 0; + if (Tcl_IsShared(varValuePtr)) { + createdNewObj = 1; + varValuePtr = Tcl_DuplicateObj(varValuePtr); + } + result = Tcl_GetLongFromObj(interp, varValuePtr, &i); + if (result != TCL_OK) { + if (createdNewObj) { + Tcl_DecrRefCount(varValuePtr); /* free unneeded copy */ + } + return NULL; + } + Tcl_SetLongObj(varValuePtr, (i + incrAmount)); + + /* + * Store the variable's new value and run any write traces. + */ + + resultPtr = TclSetIndexedScalar(interp, localIndex, varValuePtr, + /*leaveErrorMsg*/ 1); + if (resultPtr == NULL) { + return NULL; + } + return resultPtr; +} + +/* + *---------------------------------------------------------------------- + * + * TclIncrElementOfIndexedArray -- + * + * Increments the Tcl object value of an element in a local array + * variable. The element is named by the object elemPtr while the array + * is specified by its index in the active procedure's array of + * compiler allocated local variables. + * + * Results: + * Returns a pointer to the Tcl_Obj holding the new value of the + * element. If the specified array or element doesn't exist, or there + * is a clash in array usage, or an error occurs while executing + * variable traces, then NULL is returned and a message will be left in + * the interpreter's result. + * + * Side effects: + * The value of the given array element is incremented by the specified + * amount. The ref count for the returned object is _not_ incremented + * to reflect the returned reference; if you want to keep a reference + * to the object you must increment its ref count yourself. If the + * entry doesn't exist then a new variable is created. + * + *---------------------------------------------------------------------- + */ + +Tcl_Obj * +TclIncrElementOfIndexedArray(interp, localIndex, elemPtr, incrAmount) + Tcl_Interp *interp; /* Command interpreter in which the array is + * to be found. */ + int localIndex; /* Index of array variable in procedure's + * array of local variables. */ + Tcl_Obj *elemPtr; /* Points to an object holding the name of + * an element to increment in the array. */ + long incrAmount; /* Amount to be added to variable. */ +{ + register Tcl_Obj *varValuePtr; + Tcl_Obj *resultPtr; + int createdNewObj; /* Set 1 if var's value object is shared + * so we must increment a copy (i.e. copy + * on write). */ + long i; + int result; + + varValuePtr = TclGetElementOfIndexedArray(interp, localIndex, elemPtr, + /*leaveErrorMsg*/ 1); + if (varValuePtr == NULL) { + Tcl_AddObjErrorInfo(interp, + "\n (reading value of variable to increment)", -1); + return NULL; + } + + /* + * Reach into the object's representation to extract and increment the + * variable's value. If the object is unshared we can modify it + * directly, otherwise we must create a new copy to modify: this is + * "copy on write". Then free the variable's old string representation, + * if any, since it will no longer be valid. + */ + + createdNewObj = 0; + if (Tcl_IsShared(varValuePtr)) { + createdNewObj = 1; + varValuePtr = Tcl_DuplicateObj(varValuePtr); + } + result = Tcl_GetLongFromObj(interp, varValuePtr, &i); + if (result != TCL_OK) { + if (createdNewObj) { + Tcl_DecrRefCount(varValuePtr); /* free unneeded copy */ + } + return NULL; + } + Tcl_SetLongObj(varValuePtr, (i + incrAmount)); + + /* + * Store the variable's new value and run any write traces. + */ + + resultPtr = TclSetElementOfIndexedArray(interp, localIndex, elemPtr, + varValuePtr, + /*leaveErrorMsg*/ 1); + if (resultPtr == NULL) { + return NULL; + } + return resultPtr; +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_UnsetVar -- + * + * Delete a variable, so that it may not be accessed anymore. + * + * Results: + * Returns TCL_OK if the variable was successfully deleted, TCL_ERROR + * if the variable can't be unset. In the event of an error, + * if the TCL_LEAVE_ERR_MSG flag is set then an error message + * is left in interp->result. + * + * Side effects: + * If varName is defined as a local or global variable in interp, + * it is deleted. + * + *---------------------------------------------------------------------- + */ + +int +Tcl_UnsetVar(interp, varName, flags) + Tcl_Interp *interp; /* Command interpreter in which varName is + * to be looked up. */ + char *varName; /* Name of a variable in interp. May be + * either a scalar name or an array name + * or an element in an array. */ + int flags; /* OR-ed combination of any of + * TCL_GLOBAL_ONLY, TCL_NAMESPACE_ONLY or + * TCL_LEAVE_ERR_MSG. */ +{ + return Tcl_UnsetVar2(interp, varName, (char *) NULL, + (flags | TCL_PARSE_PART1)); +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_UnsetVar2 -- + * + * Delete a variable, given a 2-part name. + * + * Results: + * Returns TCL_OK if the variable was successfully deleted, TCL_ERROR + * if the variable can't be unset. In the event of an error, + * if the TCL_LEAVE_ERR_MSG flag is set then an error message + * is left in interp->result. + * + * Side effects: + * If part1 and part2 indicate a local or global variable in interp, + * it is deleted. If part1 is an array name and part2 is NULL, then + * the whole array is deleted. + * + *---------------------------------------------------------------------- + */ + +int +Tcl_UnsetVar2(interp, part1, part2, flags) + Tcl_Interp *interp; /* Command interpreter in which varName is + * to be looked up. */ + char *part1; /* Name of variable or array. */ + char *part2; /* Name of element within array or NULL. */ + int flags; /* OR-ed combination of any of + * TCL_GLOBAL_ONLY, TCL_NAMESPACE_ONLY, + * TCL_LEAVE_ERR_MSG, or + * TCL_PARSE_PART1. */ +{ + Var dummyVar; + Var *varPtr, *dummyVarPtr; + Interp *iPtr = (Interp *) interp; + Var *arrayPtr; + ActiveVarTrace *activePtr; + Tcl_Obj *objPtr; + int result; + + varPtr = TclLookupVar(interp, part1, part2, flags, "unset", + /*createPart1*/ 0, /*createPart2*/ 0, &arrayPtr); + if (varPtr == NULL) { + return TCL_ERROR; + } + result = (TclIsVarUndefined(varPtr)? TCL_ERROR : TCL_OK); + + if ((arrayPtr != NULL) && (arrayPtr->searchPtr != NULL)) { + DeleteSearches(arrayPtr); + } + + /* + * The code below is tricky, because of the possibility that + * a trace procedure might try to access a variable being + * deleted. To handle this situation gracefully, do things + * in three steps: + * 1. Copy the contents of the variable to a dummy variable + * structure, and mark the original Var structure as undefined. + * 2. Invoke traces and clean up the variable, using the dummy copy. + * 3. If at the end of this the original variable is still + * undefined and has no outstanding references, then delete + * it (but it could have gotten recreated by a trace). + */ + + dummyVar = *varPtr; + TclSetVarUndefined(varPtr); + TclSetVarScalar(varPtr); + varPtr->value.objPtr = NULL; /* dummyVar points to any value object */ + varPtr->tracePtr = NULL; + varPtr->searchPtr = NULL; + + /* + * Call trace procedures for the variable being deleted. Then delete + * its traces. Be sure to abort any other traces for the variable + * that are still pending. Special tricks: + * 1. We need to increment varPtr's refCount around this: CallTraces + * will use dummyVar so it won't increment varPtr's refCount itself. + * 2. Turn off the VAR_TRACE_ACTIVE flag in dummyVar: we want to + * call unset traces even if other traces are pending. + */ + + if ((dummyVar.tracePtr != NULL) + || ((arrayPtr != NULL) && (arrayPtr->tracePtr != NULL))) { + varPtr->refCount++; + dummyVar.flags &= ~VAR_TRACE_ACTIVE; + (void) CallTraces(iPtr, arrayPtr, &dummyVar, part1, part2, + (flags & (TCL_GLOBAL_ONLY|TCL_NAMESPACE_ONLY|TCL_PARSE_PART1)) | TCL_TRACE_UNSETS); + while (dummyVar.tracePtr != NULL) { + VarTrace *tracePtr = dummyVar.tracePtr; + dummyVar.tracePtr = tracePtr->nextPtr; + ckfree((char *) tracePtr); + } + for (activePtr = iPtr->activeTracePtr; activePtr != NULL; + activePtr = activePtr->nextPtr) { + if (activePtr->varPtr == varPtr) { + activePtr->nextTracePtr = NULL; + } + } + varPtr->refCount--; + } + + /* + * If the variable is an array, delete all of its elements. This must be + * done after calling the traces on the array, above (that's the way + * traces are defined). If it is a scalar, "discard" its object + * (decrement the ref count of its object, if any). + */ + + dummyVarPtr = &dummyVar; + if (TclIsVarArray(dummyVarPtr) && !TclIsVarUndefined(dummyVarPtr)) { + DeleteArray(iPtr, part1, dummyVarPtr, + (flags & (TCL_GLOBAL_ONLY|TCL_NAMESPACE_ONLY)) | TCL_TRACE_UNSETS); + } + if (TclIsVarScalar(dummyVarPtr) + && (dummyVarPtr->value.objPtr != NULL)) { + objPtr = dummyVarPtr->value.objPtr; + TclDecrRefCount(objPtr); + dummyVarPtr->value.objPtr = NULL; + } + + /* + * If the variable was a namespace variable, decrement its reference + * count. We are in the process of destroying its namespace so that + * namespace will no longer "refer" to the variable. + */ + + if (varPtr->flags & VAR_NAMESPACE_VAR) { + varPtr->flags &= ~VAR_NAMESPACE_VAR; + varPtr->refCount--; + } + + /* + * It's an error to unset an undefined variable. + */ + + if (result != TCL_OK) { + if (flags & TCL_LEAVE_ERR_MSG) { + VarErrMsg(interp, part1, part2, "unset", + ((arrayPtr == NULL) ? noSuchVar : noSuchElement)); + } + } + + /* + * Finally, if the variable is truly not in use then free up its Var + * structure and remove it from its hash table, if any. The ref count of + * its value object, if any, was decremented above. + */ + + CleanupVar(varPtr, arrayPtr); + return result; +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_TraceVar -- + * + * Arrange for reads and/or writes to a variable to cause a + * procedure 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. + * + *---------------------------------------------------------------------- + */ + +int +Tcl_TraceVar(interp, varName, flags, proc, clientData) + Tcl_Interp *interp; /* Interpreter in which variable is + * to be traced. */ + 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; /* Procedure to call when specified ops are + * invoked upon varName. */ + ClientData clientData; /* Arbitrary argument to pass to proc. */ +{ + return Tcl_TraceVar2(interp, varName, (char *) NULL, + (flags | TCL_PARSE_PART1), proc, clientData); +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_TraceVar2 -- + * + * Arrange for reads and/or writes to a variable to cause a + * procedure 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. + * + *---------------------------------------------------------------------- + */ + +int +Tcl_TraceVar2(interp, part1, part2, flags, proc, clientData) + Tcl_Interp *interp; /* Interpreter in which variable is + * to be traced. */ + char *part1; /* Name of scalar variable or array. */ + 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, + * TCL_NAMESPACE_ONLY and + * TCL_PARSE_PART1. */ + Tcl_VarTraceProc *proc; /* Procedure to call when specified ops are + * invoked upon varName. */ + ClientData clientData; /* Arbitrary argument to pass to proc. */ +{ + Var *varPtr, *arrayPtr; + register VarTrace *tracePtr; + + varPtr = TclLookupVar(interp, part1, part2, (flags | TCL_LEAVE_ERR_MSG), + "trace", /*createPart1*/ 1, /*createPart2*/ 1, &arrayPtr); + if (varPtr == NULL) { + return TCL_ERROR; + } + + /* + * Set up trace information. + */ + + tracePtr = (VarTrace *) ckalloc(sizeof(VarTrace)); + tracePtr->traceProc = proc; + tracePtr->clientData = clientData; + tracePtr->flags = + flags & (TCL_TRACE_READS | TCL_TRACE_WRITES | TCL_TRACE_UNSETS); + tracePtr->nextPtr = varPtr->tracePtr; + varPtr->tracePtr = tracePtr; + return TCL_OK; +} + +/* + *---------------------------------------------------------------------- + * + * 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(interp, varName, flags, proc, clientData) + Tcl_Interp *interp; /* Interpreter containing variable. */ + 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; /* Procedure assocated with trace. */ + ClientData clientData; /* Arbitrary argument to pass to proc. */ +{ + Tcl_UntraceVar2(interp, varName, (char *) NULL, + (flags | TCL_PARSE_PART1), 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(interp, part1, part2, flags, proc, clientData) + Tcl_Interp *interp; /* Interpreter containing variable. */ + char *part1; /* Name of variable or array. */ + 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, + * TCL_NAMESPACE_ONLY and + * TCL_PARSE_PART1. */ + Tcl_VarTraceProc *proc; /* Procedure assocated with trace. */ + ClientData clientData; /* Arbitrary argument to pass to proc. */ +{ + register VarTrace *tracePtr; + VarTrace *prevPtr; + Var *varPtr, *arrayPtr; + Interp *iPtr = (Interp *) interp; + ActiveVarTrace *activePtr; + + varPtr = TclLookupVar(interp, part1, part2, + flags & (TCL_GLOBAL_ONLY|TCL_NAMESPACE_ONLY|TCL_PARSE_PART1), + /*msg*/ (char *) NULL, + /*createPart1*/ 0, /*createPart2*/ 0, &arrayPtr); + if (varPtr == NULL) { + return; + } + + flags &= (TCL_TRACE_READS | TCL_TRACE_WRITES | TCL_TRACE_UNSETS); + for (tracePtr = varPtr->tracePtr, prevPtr = NULL; ; + prevPtr = tracePtr, tracePtr = tracePtr->nextPtr) { + if (tracePtr == NULL) { + return; + } + if ((tracePtr->traceProc == proc) && (tracePtr->flags == flags) + && (tracePtr->clientData == clientData)) { + 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 CallTraces. + */ + + for (activePtr = iPtr->activeTracePtr; activePtr != NULL; + activePtr = activePtr->nextPtr) { + if (activePtr->nextTracePtr == tracePtr) { + activePtr->nextTracePtr = tracePtr->nextPtr; + } + } + if (prevPtr == NULL) { + varPtr->tracePtr = tracePtr->nextPtr; + } else { + prevPtr->nextPtr = tracePtr->nextPtr; + } + ckfree((char *) tracePtr); + + /* + * If this is the last trace on the variable, and the variable is + * unset and unused, then free up the variable. + */ + + if (TclIsVarUndefined(varPtr)) { + CleanupVar(varPtr, (Var *) NULL); + } +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_VarTraceInfo -- + * + * Return the clientData value associated with a trace on a + * variable. This procedure can also be used to step through + * all of the traces on a particular variable that have the + * same trace procedure. + * + * 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 procedure. 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(interp, varName, flags, proc, prevClientData) + Tcl_Interp *interp; /* Interpreter containing variable. */ + char *varName; /* Name of variable; may end with "(index)" + * to signify an array reference. */ + int flags; /* 0, TCL_GLOBAL_ONLY, or + * TCL_NAMESPACE_ONLY. */ + Tcl_VarTraceProc *proc; /* Procedure assocated with trace. */ + ClientData prevClientData; /* If non-NULL, gives last value returned + * by this procedure, 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, (char *) NULL, + (flags | TCL_PARSE_PART1), 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(interp, part1, part2, flags, proc, prevClientData) + Tcl_Interp *interp; /* Interpreter containing variable. */ + char *part1; /* Name of variable or array. */ + 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, and + * TCL_PARSE_PART1. */ + Tcl_VarTraceProc *proc; /* Procedure assocated with trace. */ + ClientData prevClientData; /* If non-NULL, gives last value returned + * by this procedure, so this call will + * return the next trace after that one. + * If NULL, this call will return the + * first trace. */ +{ + register VarTrace *tracePtr; + Var *varPtr, *arrayPtr; + + varPtr = TclLookupVar(interp, part1, part2, + flags & (TCL_GLOBAL_ONLY|TCL_NAMESPACE_ONLY|TCL_PARSE_PART1), + /*msg*/ (char *) NULL, + /*createPart1*/ 0, /*createPart2*/ 0, &arrayPtr); + if (varPtr == NULL) { + return NULL; + } + + /* + * Find the relevant trace, if any, and return its clientData. + */ + + tracePtr = varPtr->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_UnsetObjCmd -- + * + * This object-based procedure is invoked to process the "unset" Tcl + * command. See the user documentation for details on what it does. + * + * Results: + * A standard Tcl object result value. + * + * Side effects: + * See the user documentation. + * + *---------------------------------------------------------------------- + */ + + /* ARGSUSED */ +int +Tcl_UnsetObjCmd(dummy, interp, objc, objv) + ClientData dummy; /* Not used. */ + Tcl_Interp *interp; /* Current interpreter. */ + int objc; /* Number of arguments. */ + Tcl_Obj *CONST objv[]; /* Argument objects. */ +{ + register int i; + register char *name; + + if (objc < 2) { + Tcl_WrongNumArgs(interp, 1, objv, "varName ?varName ...?"); + return TCL_ERROR; + } + + for (i = 1; i < objc; i++) { + /* + * THIS FAILS IF A NAME OBJECT'S STRING REP HAS A NULL BYTE. + */ + + name = Tcl_GetStringFromObj(objv[i], (int *) NULL); + if (Tcl_UnsetVar2(interp, name, (char *) NULL, + (TCL_LEAVE_ERR_MSG | TCL_PARSE_PART1)) != TCL_OK) { + return TCL_ERROR; + } + } + return TCL_OK; +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_AppendObjCmd -- + * + * This object-based procedure is invoked to process the "append" + * Tcl command. See the user documentation for details on what it does. + * + * Results: + * A standard Tcl object result value. + * + * Side effects: + * A variable's value may be changed. + * + *---------------------------------------------------------------------- + */ + + /* ARGSUSED */ +int +Tcl_AppendObjCmd(dummy, interp, objc, objv) + ClientData dummy; /* Not used. */ + Tcl_Interp *interp; /* Current interpreter. */ + int objc; /* Number of arguments. */ + Tcl_Obj *CONST objv[]; /* Argument objects. */ +{ + register Tcl_Obj *varValuePtr = NULL; + /* Initialized to avoid compiler + * warning. */ + int i; + + if (objc < 2) { + Tcl_WrongNumArgs(interp, 1, objv, "varName ?value value ...?"); + return TCL_ERROR; + } + + if (objc == 2) { + varValuePtr = Tcl_ObjGetVar2(interp, objv[1], (Tcl_Obj *) NULL, + (TCL_LEAVE_ERR_MSG | TCL_PARSE_PART1)); + if (varValuePtr == NULL) { + return TCL_ERROR; + } + } else { + for (i = 2; i < objc; i++) { + varValuePtr = Tcl_ObjSetVar2(interp, objv[1], (Tcl_Obj *) NULL, + objv[i], + (TCL_APPEND_VALUE | TCL_LEAVE_ERR_MSG | TCL_PARSE_PART1)); + if (varValuePtr == NULL) { + return TCL_ERROR; + } + } + } + + Tcl_SetObjResult(interp, varValuePtr); + return TCL_OK; +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_LappendObjCmd -- + * + * This object-based procedure is invoked to process the "lappend" + * Tcl command. See the user documentation for details on what it does. + * + * Results: + * A standard Tcl object result value. + * + * Side effects: + * A variable's value may be changed. + * + *---------------------------------------------------------------------- + */ + + /* ARGSUSED */ +int +Tcl_LappendObjCmd(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_Obj *varValuePtr, *newValuePtr; + register List *listRepPtr; + register Tcl_Obj **elemPtrs; + int numElems, numRequired, createdNewObj, createVar, i, j; + + if (objc < 2) { + Tcl_WrongNumArgs(interp, 1, objv, "varName ?value value ...?"); + return TCL_ERROR; + } + + if (objc == 2) { + newValuePtr = Tcl_ObjGetVar2(interp, objv[1], (Tcl_Obj *) NULL, + (TCL_LEAVE_ERR_MSG | TCL_PARSE_PART1)); + if (newValuePtr == NULL) { + /* + * The variable doesn't exist yet. Just create it with an empty + * initial value. + */ + + Tcl_Obj *nullObjPtr = Tcl_NewObj(); + newValuePtr = Tcl_ObjSetVar2(interp, objv[1], NULL, + nullObjPtr, (TCL_LEAVE_ERR_MSG | TCL_PARSE_PART1)); + if (newValuePtr == NULL) { + Tcl_DecrRefCount(nullObjPtr); /* free unneeded object */ + return TCL_ERROR; + } + } + } else { + /* + * We have arguments to append. We used to call Tcl_ObjSetVar2 to + * append each argument one at a time to ensure that traces were run + * for each append step. We now append the arguments all at once + * because it's faster. Note that a read trace and a write trace for + * the variable will now each only be called once. Also, if the + * variable's old value is unshared we modify it directly, otherwise + * we create a new copy to modify: this is "copy on write". + */ + + createdNewObj = 0; + createVar = 1; + varValuePtr = Tcl_ObjGetVar2(interp, objv[1], (Tcl_Obj *) NULL, + TCL_PARSE_PART1); + if (varValuePtr == NULL) { + /* + * We couldn't read the old value: either the var doesn't yet + * exist or it's an array element. If it's new, we will try to + * create it with Tcl_ObjSetVar2 below. + */ + + char *name, *p; + int nameBytes, i; + + name = TclGetStringFromObj(objv[1], &nameBytes); + for (i = 0, p = name; i < nameBytes; i++, p++) { + if (*p == '(') { + p = (name + nameBytes-1); + if (*p == ')') { /* last char is ')' => array ref */ + createVar = 0; + } + break; + } + } + varValuePtr = Tcl_NewObj(); + createdNewObj = 1; + } else if (Tcl_IsShared(varValuePtr)) { + varValuePtr = Tcl_DuplicateObj(varValuePtr); + createdNewObj = 1; + } + + /* + * Convert the variable's old value to a list object if necessary. + */ + + if (varValuePtr->typePtr != &tclListType) { + int result = tclListType.setFromAnyProc(interp, varValuePtr); + if (result != TCL_OK) { + if (createdNewObj) { + Tcl_DecrRefCount(varValuePtr); /* free unneeded obj. */ + } + return result; + } + } + listRepPtr = (List *) varValuePtr->internalRep.otherValuePtr; + elemPtrs = listRepPtr->elements; + numElems = listRepPtr->elemCount; + + /* + * If there is no room in the current array of element pointers, + * allocate a new, larger array and copy the pointers to it. + */ + + numRequired = numElems + (objc-2); + if (numRequired > listRepPtr->maxElemCount) { + int newMax = (2 * numRequired); + Tcl_Obj **newElemPtrs = (Tcl_Obj **) + ckalloc((unsigned) (newMax * sizeof(Tcl_Obj *))); + + memcpy((VOID *) newElemPtrs, (VOID *) elemPtrs, + (size_t) (numElems * sizeof(Tcl_Obj *))); + listRepPtr->maxElemCount = newMax; + listRepPtr->elements = newElemPtrs; + ckfree((char *) elemPtrs); + elemPtrs = newElemPtrs; + } + + /* + * Insert the new elements at the end of the list. + */ + + for (i = 2, j = numElems; i < objc; i++, j++) { + elemPtrs[j] = objv[i]; + Tcl_IncrRefCount(objv[i]); + } + listRepPtr->elemCount = numRequired; + + /* + * Invalidate and free any old string representation since it no + * longer reflects the list's internal representation. + */ + + Tcl_InvalidateStringRep(varValuePtr); + + /* + * Now store the list object back into the variable. If there is an + * error setting the new value, decrement its ref count if it + * was new and we didn't create the variable. + */ + + newValuePtr = Tcl_ObjSetVar2(interp, objv[1], (Tcl_Obj *) NULL, + varValuePtr, (TCL_LEAVE_ERR_MSG | TCL_PARSE_PART1)); + if (newValuePtr == NULL) { + if (createdNewObj && !createVar) { + Tcl_DecrRefCount(varValuePtr); /* free unneeded obj */ + } + return TCL_ERROR; + } + } + + /* + * Set the interpreter's object result to refer to the variable's value + * object. + */ + + Tcl_SetObjResult(interp, newValuePtr); + return TCL_OK; +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_ArrayObjCmd -- + * + * This object-based procedure is invoked to process the "array" Tcl + * command. See the user documentation for details on what it does. + * + * Results: + * A standard Tcl result object. + * + * Side effects: + * See the user documentation. + * + *---------------------------------------------------------------------- + */ + + /* ARGSUSED */ +int +Tcl_ArrayObjCmd(dummy, interp, objc, objv) + ClientData dummy; /* Not used. */ + Tcl_Interp *interp; /* Current interpreter. */ + int objc; /* Number of arguments. */ + Tcl_Obj *CONST objv[]; /* Argument objects. */ +{ + static char *arrayOptions[] = {"anymore", "donesearch", "exists", + "get", "names", "nextelement", "set", "size", "startsearch", + (char *) NULL}; + Var *varPtr, *arrayPtr; + Tcl_HashEntry *hPtr; + Tcl_Obj *resultPtr = Tcl_GetObjResult(interp); + int notArray; + char *varName; + int index, result; + + + if (objc < 3) { + Tcl_WrongNumArgs(interp, 1, objv, "option arrayName ?arg ...?"); + return TCL_ERROR; + } + + if (Tcl_GetIndexFromObj(interp, objv[1], arrayOptions, "option", 0, &index) + != TCL_OK) { + return TCL_ERROR; + } + + /* + * Locate the array variable (and it better be an array). + * THIS FAILS IF A NAME OBJECT'S STRING REP HAS A NULL BYTE. + */ + + varName = TclGetStringFromObj(objv[2], (int *) NULL); + varPtr = TclLookupVar(interp, varName, (char *) NULL, /*flags*/ 0, + /*msg*/ 0, /*createPart1*/ 0, /*createPart2*/ 0, &arrayPtr); + + notArray = 0; + if ((varPtr == NULL) || !TclIsVarArray(varPtr) + || TclIsVarUndefined(varPtr)) { + notArray = 1; + } + + switch (index) { + case 0: { /* anymore */ + ArraySearch *searchPtr; + char *searchId; + + if (objc != 4) { + Tcl_WrongNumArgs(interp, 2, objv, + "arrayName searchId"); + return TCL_ERROR; + } + if (notArray) { + goto error; + } + searchId = Tcl_GetStringFromObj(objv[3], (int *) NULL); + searchPtr = ParseSearchId(interp, varPtr, varName, searchId); + if (searchPtr == NULL) { + return TCL_ERROR; + } + while (1) { + Var *varPtr2; + + if (searchPtr->nextEntry != NULL) { + varPtr2 = (Var *) Tcl_GetHashValue(searchPtr->nextEntry); + if (!TclIsVarUndefined(varPtr2)) { + break; + } + } + searchPtr->nextEntry = Tcl_NextHashEntry(&searchPtr->search); + if (searchPtr->nextEntry == NULL) { + Tcl_SetIntObj(resultPtr, 0); + return TCL_OK; + } + } + Tcl_SetIntObj(resultPtr, 1); + break; + } + case 1: { /* donesearch */ + ArraySearch *searchPtr, *prevPtr; + char *searchId; + + if (objc != 4) { + Tcl_WrongNumArgs(interp, 2, objv, + "arrayName searchId"); + return TCL_ERROR; + } + if (notArray) { + goto error; + } + searchId = Tcl_GetStringFromObj(objv[3], (int *) NULL); + searchPtr = ParseSearchId(interp, varPtr, varName, searchId); + if (searchPtr == NULL) { + return TCL_ERROR; + } + if (varPtr->searchPtr == searchPtr) { + varPtr->searchPtr = searchPtr->nextPtr; + } else { + for (prevPtr = varPtr->searchPtr; ; + prevPtr = prevPtr->nextPtr) { + if (prevPtr->nextPtr == searchPtr) { + prevPtr->nextPtr = searchPtr->nextPtr; + break; + } + } + } + ckfree((char *) searchPtr); + break; + } + case 2: { /* exists */ + if (objc != 3) { + Tcl_WrongNumArgs(interp, 2, objv, "arrayName"); + return TCL_ERROR; + } + Tcl_SetIntObj(resultPtr, !notArray); + break; + } + case 3: { /*get*/ + Tcl_HashSearch search; + Var *varPtr2; + char *pattern = NULL; + char *name; + Tcl_Obj *namePtr, *valuePtr; + + if ((objc != 3) && (objc != 4)) { + Tcl_WrongNumArgs(interp, 2, objv, "arrayName ?pattern?"); + return TCL_ERROR; + } + if (notArray) { + return TCL_OK; + } + if (objc == 4) { + pattern = Tcl_GetStringFromObj(objv[3], (int *) NULL); + } + for (hPtr = Tcl_FirstHashEntry(varPtr->value.tablePtr, &search); + hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) { + varPtr2 = (Var *) Tcl_GetHashValue(hPtr); + if (TclIsVarUndefined(varPtr2)) { + continue; + } + name = Tcl_GetHashKey(varPtr->value.tablePtr, hPtr); + if ((objc == 4) && !Tcl_StringMatch(name, pattern)) { + continue; /* element name doesn't match pattern */ + } + + namePtr = Tcl_NewStringObj(name, -1); + result = Tcl_ListObjAppendElement(interp, resultPtr, + namePtr); + if (result != TCL_OK) { + Tcl_DecrRefCount(namePtr); /* free unneeded name obj */ + return result; + } + + valuePtr = Tcl_ObjGetVar2(interp, objv[2], namePtr, + TCL_LEAVE_ERR_MSG); + if (valuePtr == NULL) { + Tcl_DecrRefCount(namePtr); /* free unneeded name obj */ + return result; + } + result = Tcl_ListObjAppendElement(interp, resultPtr, + valuePtr); + if (result != TCL_OK) { + Tcl_DecrRefCount(namePtr); /* free unneeded name obj */ + return result; + } + } + break; + } + case 4: { /* names */ + Tcl_HashSearch search; + Var *varPtr2; + char *pattern = NULL; + char *name; + Tcl_Obj *namePtr; + + if ((objc != 3) && (objc != 4)) { + Tcl_WrongNumArgs(interp, 2, objv, "arrayName ?pattern?"); + return TCL_ERROR; + } + if (notArray) { + return TCL_OK; + } + if (objc == 4) { + pattern = Tcl_GetStringFromObj(objv[3], (int *) NULL); + } + for (hPtr = Tcl_FirstHashEntry(varPtr->value.tablePtr, &search); + hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) { + varPtr2 = (Var *) Tcl_GetHashValue(hPtr); + if (TclIsVarUndefined(varPtr2)) { + continue; + } + name = Tcl_GetHashKey(varPtr->value.tablePtr, hPtr); + if ((objc == 4) && !Tcl_StringMatch(name, pattern)) { + continue; /* element name doesn't match pattern */ + } + + namePtr = Tcl_NewStringObj(name, -1); + result = Tcl_ListObjAppendElement(interp, resultPtr, namePtr); + if (result != TCL_OK) { + Tcl_DecrRefCount(namePtr); /* free unneeded name object */ + return result; + } + } + break; + } + case 5: { /*nextelement*/ + ArraySearch *searchPtr; + char *searchId; + Tcl_HashEntry *hPtr; + + if (objc != 4) { + Tcl_WrongNumArgs(interp, 2, objv, + "arrayName searchId"); + return TCL_ERROR; + } + if (notArray) { + goto error; + } + searchId = Tcl_GetStringFromObj(objv[3], (int *) NULL); + searchPtr = ParseSearchId(interp, varPtr, varName, searchId); + if (searchPtr == NULL) { + return TCL_ERROR; + } + while (1) { + Var *varPtr2; + + hPtr = searchPtr->nextEntry; + if (hPtr == NULL) { + hPtr = Tcl_NextHashEntry(&searchPtr->search); + if (hPtr == NULL) { + return TCL_OK; + } + } else { + searchPtr->nextEntry = NULL; + } + varPtr2 = (Var *) Tcl_GetHashValue(hPtr); + if (!TclIsVarUndefined(varPtr2)) { + break; + } + } + Tcl_SetStringObj(resultPtr, + Tcl_GetHashKey(varPtr->value.tablePtr, hPtr), -1); + break; + } + case 6: { /*set*/ + Tcl_Obj **elemPtrs; + int listLen, i, result; + + if (objc != 4) { + Tcl_WrongNumArgs(interp, 2, objv, "arrayName list"); + return TCL_ERROR; + } + result = Tcl_ListObjGetElements(interp, objv[3], &listLen, + &elemPtrs); + if (result != TCL_OK) { + return result; + } + if (listLen & 1) { + Tcl_ResetResult(interp); + Tcl_AppendToObj(Tcl_GetObjResult(interp), + "list must have an even number of elements", -1); + return TCL_ERROR; + } + if (listLen > 0) { + for (i = 0; i < listLen; i += 2) { + if (Tcl_ObjSetVar2(interp, objv[2], elemPtrs[i], + elemPtrs[i+1], TCL_LEAVE_ERR_MSG) == NULL) { + result = TCL_ERROR; + break; + } + } + } else if (varPtr == NULL) { + /* + * The list is empty and the array variable doesn't + * exist yet: create the variable with an empty array + * as the value. + */ + + Tcl_Obj *namePtr, *valuePtr; + + namePtr = Tcl_NewStringObj("tempElem", -1); + valuePtr = Tcl_NewObj(); + if (Tcl_ObjSetVar2(interp, objv[2], namePtr, valuePtr, + /* flags*/ 0) == NULL) { + Tcl_DecrRefCount(namePtr); + Tcl_DecrRefCount(valuePtr); + return TCL_ERROR; + } + result = Tcl_UnsetVar2(interp, varName, "tempElem", + TCL_LEAVE_ERR_MSG); + if (result != TCL_OK) { + Tcl_DecrRefCount(namePtr); + Tcl_DecrRefCount(valuePtr); + return result; + } + } + return result; + } + case 7: { /*size*/ + Tcl_HashSearch search; + Var *varPtr2; + int size; + + if (objc != 3) { + Tcl_WrongNumArgs(interp, 2, objv, "arrayName"); + return TCL_ERROR; + } + size = 0; + if (!notArray) { + for (hPtr = Tcl_FirstHashEntry(varPtr->value.tablePtr, + &search); + hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) { + varPtr2 = (Var *) Tcl_GetHashValue(hPtr); + if (TclIsVarUndefined(varPtr2)) { + continue; + } + size++; + } + } + Tcl_SetIntObj(resultPtr, size); + break; + } + case 8: { /*startsearch*/ + ArraySearch *searchPtr; + + if (objc != 3) { + Tcl_WrongNumArgs(interp, 2, objv, "arrayName"); + return TCL_ERROR; + } + if (notArray) { + goto error; + } + searchPtr = (ArraySearch *) ckalloc(sizeof(ArraySearch)); + if (varPtr->searchPtr == NULL) { + searchPtr->id = 1; + Tcl_AppendStringsToObj(resultPtr, "s-1-", varName, + (char *) NULL); + } else { + char string[20]; + + searchPtr->id = varPtr->searchPtr->id + 1; + TclFormatInt(string, searchPtr->id); + Tcl_AppendStringsToObj(resultPtr, "s-", string, "-", varName, + (char *) NULL); + } + searchPtr->varPtr = varPtr; + searchPtr->nextEntry = Tcl_FirstHashEntry(varPtr->value.tablePtr, + &searchPtr->search); + searchPtr->nextPtr = varPtr->searchPtr; + varPtr->searchPtr = searchPtr; + break; + } + } + return TCL_OK; + + error: + Tcl_AppendStringsToObj(resultPtr, "\"", varName, "\" isn't an array", + (char *) NULL); + return TCL_ERROR; +} + +/* + *---------------------------------------------------------------------- + * + * MakeUpvar -- + * + * This procedure does all of the work of the "global" and "upvar" + * commands. + * + * Results: + * A standard Tcl completion code. If an error occurs then an + * error message is left in iPtr->result. + * + * Side effects: + * The variable given by myName is linked to the variable in framePtr + * given by otherP1 and otherP2, so that references to myName are + * redirected to the other variable like a symbolic link. + * + *---------------------------------------------------------------------- + */ + +static int +MakeUpvar(iPtr, framePtr, otherP1, otherP2, otherFlags, myName, myFlags) + Interp *iPtr; /* Interpreter containing variables. Used + * for error messages, too. */ + CallFrame *framePtr; /* Call frame containing "other" variable. + * NULL means use global :: context. */ + char *otherP1, *otherP2; /* Two-part name of variable in framePtr. */ + int otherFlags; /* 0, TCL_GLOBAL_ONLY or TCL_NAMESPACE_ONLY: + * indicates scope of "other" variable. */ + char *myName; /* Name of variable which will refer to + * otherP1/otherP2. Must be a scalar. */ + int myFlags; /* 0, TCL_GLOBAL_ONLY or TCL_NAMESPACE_ONLY: + * indicates scope of myName. */ +{ + Tcl_HashEntry *hPtr; + Var *otherPtr, *varPtr, *arrayPtr; + CallFrame *varFramePtr; + CallFrame *savedFramePtr = NULL; /* Init. to avoid compiler warning. */ + Tcl_HashTable *tablePtr; + Namespace *nsPtr, *altNsPtr, *dummyNsPtr; + char *tail; + int new, result; + + /* + * Find "other" in "framePtr". If not looking up other in just the + * current namespace, temporarily replace the current var frame + * pointer in the interpreter in order to use TclLookupVar. + */ + + if (!(otherFlags & TCL_NAMESPACE_ONLY)) { + savedFramePtr = iPtr->varFramePtr; + iPtr->varFramePtr = framePtr; + } + otherPtr = TclLookupVar((Tcl_Interp *) iPtr, otherP1, otherP2, + (otherFlags | TCL_LEAVE_ERR_MSG), "access", + /*createPart1*/ 1, /*createPart2*/ 1, &arrayPtr); + if (!(otherFlags & TCL_NAMESPACE_ONLY)) { + iPtr->varFramePtr = savedFramePtr; + } + if (otherPtr == NULL) { + return TCL_ERROR; + } + + /* + * Now create a hashtable entry for "myName". Create it as either a + * namespace variable or as a local variable in a procedure call + * frame. Interpret myName as a namespace variable if: + * 1) so requested by a TCL_GLOBAL_ONLY or TCL_NAMESPACE_ONLY flag, + * 2) there is no active frame (we're at the global :: scope), + * 3) the active frame was pushed to define the namespace context + * for a "namespace eval" or "namespace inscope" command, + * 4) the name has namespace qualifiers ("::"s). + * If creating myName in the active procedure, look first in the + * frame's array of compiler-allocated local variables, then in its + * hashtable for runtime-created local variables. Create that + * procedure's local variable hashtable if necessary. + */ + + varFramePtr = iPtr->varFramePtr; + if ((myFlags & (TCL_GLOBAL_ONLY | TCL_NAMESPACE_ONLY)) + || (varFramePtr == NULL) + || !varFramePtr->isProcCallFrame + || (strstr(myName, "::") != NULL)) { + result = TclGetNamespaceForQualName((Tcl_Interp *) iPtr, myName, + (Namespace *) NULL, (myFlags | TCL_LEAVE_ERR_MSG), + &nsPtr, &altNsPtr, &dummyNsPtr, &tail); + if (result != TCL_OK) { + return result; + } + if (nsPtr == NULL) { + nsPtr = altNsPtr; + } + if (nsPtr == NULL) { + Tcl_AppendResult((Tcl_Interp *) iPtr, "bad variable name \"", + myName, "\": unknown namespace", (char *) NULL); + return TCL_ERROR; + } + + /* + * Check that we are not trying to create a namespace var linked to + * a local variable in a procedure. If we allowed this, the local + * variable in the shorter-lived procedure frame could go away + * leaving the namespace var's reference invalid. + */ + + if (otherPtr->nsPtr == NULL) { + Tcl_AppendResult((Tcl_Interp *) iPtr, "bad variable name \"", + myName, "\": upvar won't create namespace variable that refers to procedure variable", + (char *) NULL); + return TCL_ERROR; + } + + hPtr = Tcl_CreateHashEntry(&nsPtr->varTable, tail, &new); + if (new) { + varPtr = NewVar(); + Tcl_SetHashValue(hPtr, varPtr); + varPtr->hPtr = hPtr; + varPtr->nsPtr = nsPtr; + } else { + varPtr = (Var *) Tcl_GetHashValue(hPtr); + } + } else { /* look in the call frame */ + Proc *procPtr = varFramePtr->procPtr; + int localCt = procPtr->numCompiledLocals; + CompiledLocal *localPtr = procPtr->firstLocalPtr; + Var *localVarPtr = varFramePtr->compiledLocals; + int nameLen = strlen(myName); + int i; + + varPtr = NULL; + for (i = 0; i < localCt; i++) { + if (!localPtr->isTemp) { + char *localName = localVarPtr->name; + if ((myName[0] == localName[0]) + && (nameLen == localPtr->nameLength) + && (strcmp(myName, localName) == 0)) { + varPtr = localVarPtr; + new = 0; + break; + } + } + localVarPtr++; + localPtr = localPtr->nextPtr; + } + if (varPtr == NULL) { /* look in frame's local var hashtable */ + tablePtr = varFramePtr->varTablePtr; + if (tablePtr == NULL) { + tablePtr = (Tcl_HashTable *) ckalloc(sizeof(Tcl_HashTable)); + Tcl_InitHashTable(tablePtr, TCL_STRING_KEYS); + varFramePtr->varTablePtr = tablePtr; + } + hPtr = Tcl_CreateHashEntry(tablePtr, myName, &new); + if (new) { + varPtr = NewVar(); + Tcl_SetHashValue(hPtr, varPtr); + varPtr->hPtr = hPtr; + varPtr->nsPtr = varFramePtr->nsPtr; + } else { + varPtr = (Var *) Tcl_GetHashValue(hPtr); + } + } + } + + if (!new) { + /* + * The variable already exists. Make sure this variable "varPtr" + * isn't the same as "otherPtr" (avoid circular links). Also, if + * it's not an upvar then it's an error. If it is an upvar, then + * just disconnect it from the thing it currently refers to. + */ + + if (varPtr == otherPtr) { + Tcl_SetResult((Tcl_Interp *) iPtr, + "can't upvar from variable to itself", TCL_STATIC); + return TCL_ERROR; + } + if (TclIsVarLink(varPtr)) { + Var *linkPtr = varPtr->value.linkPtr; + if (linkPtr == otherPtr) { + return TCL_OK; + } + linkPtr->refCount--; + if (TclIsVarUndefined(linkPtr)) { + CleanupVar(linkPtr, (Var *) NULL); + } + } else if (!TclIsVarUndefined(varPtr)) { + Tcl_AppendResult((Tcl_Interp *) iPtr, "variable \"", myName, + "\" already exists", (char *) NULL); + return TCL_ERROR; + } else if (varPtr->tracePtr != NULL) { + Tcl_AppendResult((Tcl_Interp *) iPtr, "variable \"", myName, + "\" has traces: can't use for upvar", (char *) NULL); + return TCL_ERROR; + } + } + TclSetVarLink(varPtr); + TclClearVarUndefined(varPtr); + varPtr->value.linkPtr = otherPtr; + otherPtr->refCount++; + return TCL_OK; +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_UpVar -- + * + * This procedure links one variable to another, just like + * the "upvar" command. + * + * Results: + * A standard Tcl completion code. If an error occurs then + * an error message is left in interp->result. + * + * Side effects: + * The variable in frameName whose name is given by varName becomes + * accessible under the name localName, so that references to + * localName are redirected to the other variable like a symbolic + * link. + * + *---------------------------------------------------------------------- + */ + +int +Tcl_UpVar(interp, frameName, varName, localName, flags) + Tcl_Interp *interp; /* Command interpreter in which varName is + * to be looked up. */ + char *frameName; /* Name of the frame containing the source + * variable, such as "1" or "#0". */ + char *varName; /* Name of a variable in interp to link to. + * May be either a scalar name or an + * element in an array. */ + char *localName; /* Name of link variable. */ + int flags; /* 0, TCL_GLOBAL_ONLY or TCL_NAMESPACE_ONLY: + * indicates scope of localName. */ +{ + int result; + CallFrame *framePtr; + register char *p; + + result = TclGetFrame(interp, frameName, &framePtr); + if (result == -1) { + return TCL_ERROR; + } + + /* + * Figure out whether varName is an array reference, then call + * MakeUpvar to do all the real work. + */ + + for (p = varName; *p != '\0'; p++) { + if (*p == '(') { + char *openParen = p; + do { + p++; + } while (*p != '\0'); + p--; + if (*p != ')') { + goto scalar; + } + *openParen = '\0'; + *p = '\0'; + result = MakeUpvar((Interp *) interp, framePtr, varName, + openParen+1, 0, localName, flags); + *openParen = '('; + *p = ')'; + return result; + } + } + + scalar: + return MakeUpvar((Interp *) interp, framePtr, varName, (char *) NULL, + 0, localName, flags); +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_UpVar2 -- + * + * This procedure links one variable to another, just like + * the "upvar" command. + * + * Results: + * A standard Tcl completion code. If an error occurs then + * an error message is left in interp->result. + * + * Side effects: + * The variable in frameName whose name is given by part1 and + * part2 becomes accessible under the name localName, so that + * references to localName are redirected to the other variable + * like a symbolic link. + * + *---------------------------------------------------------------------- + */ + +int +Tcl_UpVar2(interp, frameName, part1, part2, localName, flags) + Tcl_Interp *interp; /* Interpreter containing variables. Used + * for error messages too. */ + char *frameName; /* Name of the frame containing the source + * variable, such as "1" or "#0". */ + char *part1, *part2; /* Two parts of source variable name to + * link to. */ + char *localName; /* Name of link variable. */ + int flags; /* 0, TCL_GLOBAL_ONLY or TCL_NAMESPACE_ONLY: + * indicates scope of localName. */ +{ + int result; + CallFrame *framePtr; + + result = TclGetFrame(interp, frameName, &framePtr); + if (result == -1) { + return TCL_ERROR; + } + return MakeUpvar((Interp *) interp, framePtr, part1, part2, 0, + localName, flags); +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_GetVariableFullName -- + * + * Given a Tcl_Var token returned by Tcl_FindNamespaceVar, this + * procedure appends to an object the namespace variable's full + * name, qualified by a sequence of parent namespace names. + * + * Results: + * None. + * + * Side effects: + * The variable's fully-qualified name is appended to the string + * representation of objPtr. + * + *---------------------------------------------------------------------- + */ + +void +Tcl_GetVariableFullName(interp, variable, objPtr) + Tcl_Interp *interp; /* Interpreter containing the variable. */ + Tcl_Var variable; /* Token for the variable returned by a + * previous call to Tcl_FindNamespaceVar. */ + Tcl_Obj *objPtr; /* Points to the object onto which the + * variable's full name is appended. */ +{ + Interp *iPtr = (Interp *) interp; + register Var *varPtr = (Var *) variable; + char *name; + + /* + * Add the full name of the containing namespace (if any), followed by + * the "::" separator, then the variable name. + */ + + if (varPtr != NULL) { + if (!TclIsVarArrayElement(varPtr)) { + if (varPtr->nsPtr != NULL) { + Tcl_AppendToObj(objPtr, varPtr->nsPtr->fullName, -1); + if (varPtr->nsPtr != iPtr->globalNsPtr) { + Tcl_AppendToObj(objPtr, "::", 2); + } + } + if (varPtr->name != NULL) { + Tcl_AppendToObj(objPtr, varPtr->name, -1); + } else if (varPtr->hPtr != NULL) { + name = Tcl_GetHashKey(varPtr->hPtr->tablePtr, varPtr->hPtr); + Tcl_AppendToObj(objPtr, name, -1); + } + } + } +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_GlobalObjCmd -- + * + * This object-based procedure is invoked to process the "global" Tcl + * command. See the user documentation for details on what it does. + * + * Results: + * A standard Tcl object result value. + * + * Side effects: + * See the user documentation. + * + *---------------------------------------------------------------------- + */ + +int +Tcl_GlobalObjCmd(dummy, interp, objc, objv) + ClientData dummy; /* Not used. */ + Tcl_Interp *interp; /* Current interpreter. */ + int objc; /* Number of arguments. */ + Tcl_Obj *CONST objv[]; /* Argument objects. */ +{ + Interp *iPtr = (Interp *) interp; + register Tcl_Obj *objPtr; + char *varName; + register char *tail; + int result, i; + + if (objc < 2) { + Tcl_WrongNumArgs(interp, 1, objv, "varName ?varName ...?"); + return TCL_ERROR; + } + + /* + * If we are not executing inside a Tcl procedure, just return. + */ + + if ((iPtr->varFramePtr == NULL) + || !iPtr->varFramePtr->isProcCallFrame) { + return TCL_OK; + } + + for (i = 1; i < objc; i++) { + /* + * Make a local variable linked to its counterpart in the global :: + * namespace. + */ + + objPtr = objv[i]; + varName = Tcl_GetStringFromObj(objPtr, (int *) NULL); + + /* + * The variable name might have a scope qualifier, but the name for + * the local "link" variable must be the simple name at the tail. + */ + + for (tail = varName; *tail != '\0'; tail++) { + /* empty body */ + } + while ((tail > varName) && ((*tail != ':') || (*(tail-1) != ':'))) { + tail--; + } + if (*tail == ':') { + tail++; + } + + /* + * Link to the variable "varName" in the global :: namespace. + */ + + result = MakeUpvar(iPtr, (CallFrame *) NULL, + varName, (char *) NULL, /*otherFlags*/ TCL_GLOBAL_ONLY, + /*myName*/ tail, /*myFlags*/ 0); + if (result != TCL_OK) { + return result; + } + } + return TCL_OK; +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_VariableObjCmd -- + * + * Invoked to implement the "variable" command that creates one or more + * global variables. Handles the following syntax: + * + * variable ?name value...? name ?value? + * + * One or more variables can be created. The variables are initialized + * with the specified values. The value for the last variable is + * optional. + * + * If the variable does not exist, it is created and given the optional + * value. If it already exists, it is simply set to the optional + * value. Normally, "name" is an unqualified name, so it is created in + * the current namespace. If it includes namespace qualifiers, it can + * be created in another namespace. + * + * If the variable command is executed inside a Tcl procedure, it + * creates a local variable linked to the newly-created namespace + * variable. + * + * Results: + * Returns TCL_OK if the variable is found or created. Returns + * TCL_ERROR if anything goes wrong. + * + * Side effects: + * If anything goes wrong, this procedure returns an error message + * as the result in the interpreter's result object. + * + *---------------------------------------------------------------------- + */ + +int +Tcl_VariableObjCmd(dummy, interp, objc, objv) + ClientData dummy; /* Not used. */ + Tcl_Interp *interp; /* Current interpreter. */ + int objc; /* Number of arguments. */ + Tcl_Obj *CONST objv[]; /* Argument objects. */ +{ + Interp *iPtr = (Interp *) interp; + char *varName, *tail; + Var *varPtr, *arrayPtr; + Tcl_Obj *varValuePtr; + int i, result; + + for (i = 1; i < objc; i = i+2) { + /* + * Look up each variable in the current namespace context, creating + * it if necessary. + */ + + varName = Tcl_GetStringFromObj(objv[i], (int *) NULL); + varPtr = TclLookupVar(interp, varName, (char *) NULL, + (TCL_NAMESPACE_ONLY | TCL_LEAVE_ERR_MSG), "define", + /*createPart1*/ 1, /*createPart2*/ 0, &arrayPtr); + if (varPtr == NULL) { + return TCL_ERROR; + } + + /* + * Mark the variable as a namespace variable and increment its + * reference count so that it will persist until its namespace is + * destroyed or until the variable is unset. + */ + + if (!(varPtr->flags & VAR_NAMESPACE_VAR)) { + varPtr->flags |= VAR_NAMESPACE_VAR; + varPtr->refCount++; + } + + /* + * If a value was specified, set the variable to that value. + * Otherwise, if the variable is new, leave it undefined. + * (If the variable already exists and no value was specified, + * leave its value unchanged; just create the local link if + * we're in a Tcl procedure). + */ + + if (i+1 < objc) { /* a value was specified */ + varValuePtr = Tcl_ObjSetVar2(interp, objv[i], (Tcl_Obj *) NULL, + objv[i+1], (TCL_NAMESPACE_ONLY | TCL_LEAVE_ERR_MSG)); + if (varValuePtr == NULL) { + return TCL_ERROR; + } + } + + /* + * If we are executing inside a Tcl procedure, create a local + * variable linked to the new namespace variable "varName". + */ + + if ((iPtr->varFramePtr != NULL) + && iPtr->varFramePtr->isProcCallFrame) { + /* + * varName might have a scope qualifier, but the name for the + * local "link" variable must be the simple name at the tail. + */ + + for (tail = varName; *tail != '\0'; tail++) { + /* empty body */ + } + while ((tail > varName) + && ((*tail != ':') || (*(tail-1) != ':'))) { + tail--; + } + if (*tail == ':') { + tail++; + } + + /* + * Create a local link "tail" to the variable "varName" in the + * current namespace. + */ + + result = MakeUpvar(iPtr, (CallFrame *) NULL, + /*otherP1*/ varName, /*otherP2*/ (char *) NULL, + /*otherFlags*/ TCL_NAMESPACE_ONLY, + /*myName*/ tail, /*myFlags*/ 0); + if (result != TCL_OK) { + return result; + } + } + } + return TCL_OK; +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_UpvarObjCmd -- + * + * This object-based procedure is invoked to process the "upvar" + * Tcl command. See the user documentation for details on what it does. + * + * Results: + * A standard Tcl object result value. + * + * Side effects: + * See the user documentation. + * + *---------------------------------------------------------------------- + */ + + /* ARGSUSED */ +int +Tcl_UpvarObjCmd(dummy, interp, objc, objv) + ClientData dummy; /* Not used. */ + Tcl_Interp *interp; /* Current interpreter. */ + int objc; /* Number of arguments. */ + Tcl_Obj *CONST objv[]; /* Argument objects. */ +{ + register Interp *iPtr = (Interp *) interp; + CallFrame *framePtr; + char *frameSpec, *otherVarName, *myVarName; + register char *p; + int result; + + if (objc < 3) { + upvarSyntax: + Tcl_WrongNumArgs(interp, 1, objv, + "?level? otherVar localVar ?otherVar localVar ...?"); + return TCL_ERROR; + } + + /* + * Find the call frame containing each of the "other variables" to be + * linked to. FAILS IF objv[1]'s STRING REP CONTAINS NULLS. + */ + + frameSpec = Tcl_GetStringFromObj(objv[1], (int *) NULL); + result = TclGetFrame(interp, frameSpec, &framePtr); + if (result == -1) { + return TCL_ERROR; + } + objc -= result+1; + if ((objc & 1) != 0) { + goto upvarSyntax; + } + objv += result+1; + + /* + * Iterate over each (other variable, local variable) pair. + * Divide the other variable name into two parts, then call + * MakeUpvar to do all the work of linking it to the local variable. + */ + + for ( ; objc > 0; objc -= 2, objv += 2) { + myVarName = Tcl_GetStringFromObj(objv[1], (int *) NULL); + otherVarName = Tcl_GetStringFromObj(objv[0], (int *) NULL); + for (p = otherVarName; *p != 0; p++) { + if (*p == '(') { + char *openParen = p; + + do { + p++; + } while (*p != '\0'); + p--; + if (*p != ')') { + goto scalar; + } + *openParen = '\0'; + *p = '\0'; + result = MakeUpvar(iPtr, framePtr, + otherVarName, openParen+1, /*otherFlags*/ 0, + myVarName, /*flags*/ 0); + *openParen = '('; + *p = ')'; + goto checkResult; + } + } + scalar: + result = MakeUpvar(iPtr, framePtr, otherVarName, (char *) NULL, 0, + myVarName, /*flags*/ 0); + + checkResult: + if (result != TCL_OK) { + return TCL_ERROR; + } + } + return TCL_OK; +} + +/* + *---------------------------------------------------------------------- + * + * CallTraces -- + * + * This procedure is invoked to find and invoke relevant + * trace procedures associated with a particular operation on + * a variable. This procedure invokes traces both on the + * variable and on its containing array (where relevant). + * + * Results: + * The return value is NULL if no trace procedures were invoked, or + * if all the invoked trace procedures returned successfully. + * The return value is non-NULL if a trace procedure returned an + * error (in this case no more trace procedures were invoked after + * the error was returned). In this case the return value is a + * pointer to a static string describing the error. + * + * Side effects: + * Almost anything can happen, depending on trace; this procedure + * itself doesn't have any side effects. + * + *---------------------------------------------------------------------- + */ + +static char * +CallTraces(iPtr, arrayPtr, varPtr, part1, part2, flags) + 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. */ + char *part1, *part2; /* Variable's two-part name. */ + int flags; /* Flags passed to trace procedures: + * indicates what's happening to variable, + * plus other stuff like TCL_GLOBAL_ONLY, + * TCL_NAMESPACE_ONLY, and + * TCL_INTERP_DESTROYED. May also contain + * TCL_PARSE_PART1, which should not be + * passed through to callbacks. */ +{ + register VarTrace *tracePtr; + ActiveVarTrace active; + char *result, *openParen, *p; + Tcl_DString nameCopy; + int copiedName; + + /* + * If there are already similar trace procedures active for the + * variable, don't call them again. + */ + + if (varPtr->flags & VAR_TRACE_ACTIVE) { + return NULL; + } + varPtr->flags |= VAR_TRACE_ACTIVE; + varPtr->refCount++; + + /* + * 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 (flags & TCL_PARSE_PART1) { + for (p = part1; ; p++) { + if (*p == 0) { + break; + } + if (*p == '(') { + openParen = p; + do { + p++; + } while (*p != '\0'); + p--; + if (*p == ')') { + Tcl_DStringInit(&nameCopy); + Tcl_DStringAppend(&nameCopy, part1, (p-part1)); + part2 = Tcl_DStringValue(&nameCopy) + + (openParen + 1 - part1); + part2[-1] = 0; + part1 = Tcl_DStringValue(&nameCopy); + copiedName = 1; + } + break; + } + } + } + flags &= ~TCL_PARSE_PART1; + + /* + * Invoke traces on the array containing the variable, if relevant. + */ + + result = NULL; + active.nextPtr = iPtr->activeTracePtr; + iPtr->activeTracePtr = &active; + if (arrayPtr != NULL) { + arrayPtr->refCount++; + active.varPtr = arrayPtr; + for (tracePtr = arrayPtr->tracePtr; tracePtr != NULL; + tracePtr = active.nextTracePtr) { + active.nextTracePtr = tracePtr->nextPtr; + if (!(tracePtr->flags & flags)) { + continue; + } + result = (*tracePtr->traceProc)(tracePtr->clientData, + (Tcl_Interp *) iPtr, part1, part2, flags); + if (result != NULL) { + if (flags & TCL_TRACE_UNSETS) { + result = NULL; + } else { + goto done; + } + } + } + } + + /* + * Invoke traces on the variable itself. + */ + + if (flags & TCL_TRACE_UNSETS) { + flags |= TCL_TRACE_DESTROYED; + } + active.varPtr = varPtr; + for (tracePtr = varPtr->tracePtr; tracePtr != NULL; + tracePtr = active.nextTracePtr) { + active.nextTracePtr = tracePtr->nextPtr; + if (!(tracePtr->flags & flags)) { + continue; + } + result = (*tracePtr->traceProc)(tracePtr->clientData, + (Tcl_Interp *) iPtr, part1, part2, flags); + if (result != NULL) { + if (flags & TCL_TRACE_UNSETS) { + result = NULL; + } else { + goto done; + } + } + } + + /* + * Restore the variable's flags, remove the record of our active + * traces, and then return. + */ + + done: + if (arrayPtr != NULL) { + arrayPtr->refCount--; + } + if (copiedName) { + Tcl_DStringFree(&nameCopy); + } + varPtr->flags &= ~VAR_TRACE_ACTIVE; + varPtr->refCount--; + iPtr->activeTracePtr = active.nextPtr; + return result; +} + +/* + *---------------------------------------------------------------------- + * + * NewVar -- + * + * Create a new heap-allocated variable that will eventually be + * entered into a hashtable. + * + * Results: + * The return value is a pointer to the new variable structure. It is + * marked as a scalar variable (and not a link or array variable). Its + * value initially is NULL. The variable is not part of any hash table + * yet. Since it will be in a hashtable and not in a call frame, its + * name field is set NULL. It is initially marked as undefined. + * + * Side effects: + * Storage gets allocated. + * + *---------------------------------------------------------------------- + */ + +static Var * +NewVar() +{ + register Var *varPtr; + + varPtr = (Var *) ckalloc(sizeof(Var)); + varPtr->value.objPtr = NULL; + varPtr->name = NULL; + varPtr->nsPtr = NULL; + varPtr->hPtr = NULL; + varPtr->refCount = 0; + varPtr->tracePtr = NULL; + varPtr->searchPtr = NULL; + varPtr->flags = (VAR_SCALAR | VAR_UNDEFINED | VAR_IN_HASHTABLE); + return varPtr; +} + +/* + *---------------------------------------------------------------------- + * + * ParseSearchId -- + * + * This procedure translates from a string to a pointer to an + * active array search (if there is one that matches the string). + * + * Results: + * The return value is a pointer to the array search indicated + * by string, or NULL if there isn't one. If NULL is returned, + * interp->result contains an error message. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +static ArraySearch * +ParseSearchId(interp, varPtr, varName, string) + Tcl_Interp *interp; /* Interpreter containing variable. */ + Var *varPtr; /* Array variable search is for. */ + char *varName; /* Name of array variable that search is + * supposed to be for. */ + char *string; /* String containing id of search. Must have + * form "search-num-var" where "num" is a + * decimal number and "var" is a variable + * name. */ +{ + char *end; + int id; + ArraySearch *searchPtr; + + /* + * Parse the id into the three parts separated by dashes. + */ + + if ((string[0] != 's') || (string[1] != '-')) { + syntax: + Tcl_AppendResult(interp, "illegal search identifier \"", string, + "\"", (char *) NULL); + return NULL; + } + id = strtoul(string+2, &end, 10); + if ((end == (string+2)) || (*end != '-')) { + goto syntax; + } + if (strcmp(end+1, varName) != 0) { + Tcl_AppendResult(interp, "search identifier \"", string, + "\" isn't for variable \"", varName, "\"", (char *) NULL); + return NULL; + } + + /* + * Search through the list of active searches on the interpreter + * to see if the desired one exists. + */ + + for (searchPtr = varPtr->searchPtr; searchPtr != NULL; + searchPtr = searchPtr->nextPtr) { + if (searchPtr->id == id) { + return searchPtr; + } + } + Tcl_AppendResult(interp, "couldn't find search \"", string, "\"", + (char *) NULL); + return NULL; +} + +/* + *---------------------------------------------------------------------- + * + * DeleteSearches -- + * + * This procedure is called to free up all of the searches + * associated with an array variable. + * + * Results: + * None. + * + * Side effects: + * Memory is released to the storage allocator. + * + *---------------------------------------------------------------------- + */ + +static void +DeleteSearches(arrayVarPtr) + register Var *arrayVarPtr; /* Variable whose searches are + * to be deleted. */ +{ + ArraySearch *searchPtr; + + while (arrayVarPtr->searchPtr != NULL) { + searchPtr = arrayVarPtr->searchPtr; + arrayVarPtr->searchPtr = searchPtr->nextPtr; + ckfree((char *) searchPtr); + } +} + +/* + *---------------------------------------------------------------------- + * + * TclDeleteVars -- + * + * This procedure is called to recycle all the storage space + * associated with a table of variables. For this procedure + * to work correctly, it must not be possible for any of the + * variables in the table to be accessed from Tcl commands + * (e.g. from trace procedures). + * + * Results: + * None. + * + * Side effects: + * Variables are deleted and trace procedures are invoked, if + * any are declared. + * + *---------------------------------------------------------------------- + */ + +void +TclDeleteVars(iPtr, tablePtr) + Interp *iPtr; /* Interpreter to which variables belong. */ + Tcl_HashTable *tablePtr; /* Hash table containing variables to + * delete. */ +{ + Tcl_Interp *interp = (Tcl_Interp *) iPtr; + Tcl_HashSearch search; + Tcl_HashEntry *hPtr; + register Var *varPtr; + Var *linkPtr; + int flags; + ActiveVarTrace *activePtr; + Tcl_Obj *objPtr; + Namespace *currNsPtr = (Namespace *) Tcl_GetCurrentNamespace(interp); + + /* + * Determine what flags to pass to the trace callback procedures. + */ + + flags = TCL_TRACE_UNSETS; + if (tablePtr == &iPtr->globalNsPtr->varTable) { + flags |= (TCL_INTERP_DESTROYED | TCL_GLOBAL_ONLY); + } else if (tablePtr == &currNsPtr->varTable) { + flags |= TCL_NAMESPACE_ONLY; + } + + for (hPtr = Tcl_FirstHashEntry(tablePtr, &search); hPtr != NULL; + hPtr = Tcl_NextHashEntry(&search)) { + varPtr = (Var *) Tcl_GetHashValue(hPtr); + + /* + * For global/upvar variables referenced in procedures, decrement + * the reference count on the variable referred to, and free + * the referenced variable if it's no longer needed. Don't delete + * the hash entry for the other variable if it's in the same table + * as us: this will happen automatically later on. + */ + + if (TclIsVarLink(varPtr)) { + linkPtr = varPtr->value.linkPtr; + linkPtr->refCount--; + if ((linkPtr->refCount == 0) && TclIsVarUndefined(linkPtr) + && (linkPtr->tracePtr == NULL) + && (linkPtr->flags & VAR_IN_HASHTABLE)) { + if (linkPtr->hPtr == NULL) { + ckfree((char *) linkPtr); + } else if (linkPtr->hPtr->tablePtr != tablePtr) { + Tcl_DeleteHashEntry(linkPtr->hPtr); + ckfree((char *) linkPtr); + } + } + } + + /* + * Invoke traces on the variable that is being deleted, then + * free up the variable's space (no need to free the hash entry + * here, unless we're dealing with a global variable: the + * hash entries will be deleted automatically when the whole + * table is deleted). Note that we give CallTraces the variable's + * fully-qualified name so that any called trace procedures can + * refer to these variables being deleted. + */ + + if (varPtr->tracePtr != NULL) { + objPtr = Tcl_NewObj(); + Tcl_IncrRefCount(objPtr); /* until done with traces */ + Tcl_GetVariableFullName(interp, (Tcl_Var) varPtr, objPtr); + (void) CallTraces(iPtr, (Var *) NULL, varPtr, + Tcl_GetStringFromObj(objPtr, (int *) NULL), + (char *) NULL, flags); + Tcl_DecrRefCount(objPtr); /* free no longer needed obj */ + + while (varPtr->tracePtr != NULL) { + VarTrace *tracePtr = varPtr->tracePtr; + varPtr->tracePtr = tracePtr->nextPtr; + ckfree((char *) tracePtr); + } + for (activePtr = iPtr->activeTracePtr; activePtr != NULL; + activePtr = activePtr->nextPtr) { + if (activePtr->varPtr == varPtr) { + activePtr->nextTracePtr = NULL; + } + } + } + + if (TclIsVarArray(varPtr)) { + DeleteArray(iPtr, Tcl_GetHashKey(tablePtr, hPtr), varPtr, + flags); + } + if (TclIsVarScalar(varPtr) && (varPtr->value.objPtr != NULL)) { + objPtr = varPtr->value.objPtr; + TclDecrRefCount(objPtr); + varPtr->value.objPtr = NULL; + } + varPtr->hPtr = NULL; + varPtr->tracePtr = NULL; + TclSetVarUndefined(varPtr); + TclSetVarScalar(varPtr); + + /* + * If the variable was a namespace variable, decrement its + * reference count. We are in the process of destroying its + * namespace so that namespace will no longer "refer" to the + * variable. + */ + + if (varPtr->flags & VAR_NAMESPACE_VAR) { + varPtr->flags &= ~VAR_NAMESPACE_VAR; + varPtr->refCount--; + } + + /* + * Recycle the variable's memory space if there aren't any upvar's + * pointing to it. If there are upvars to this variable, then the + * variable will get freed when the last upvar goes away. + */ + + if (varPtr->refCount == 0) { + ckfree((char *) varPtr); /* this Var must be VAR_IN_HASHTABLE */ + } + } + Tcl_DeleteHashTable(tablePtr); +} + +/* + *---------------------------------------------------------------------- + * + * TclDeleteCompiledLocalVars -- + * + * This procedure is called to recycle storage space associated with + * the compiler-allocated array of local variables in a procedure call + * frame. This procedure resembles TclDeleteVars above except that each + * variable is stored in a call frame and not a hash table. For this + * procedure to work correctly, it must not be possible for any of the + * variable in the table to be accessed from Tcl commands (e.g. from + * trace procedures). + * + * Results: + * None. + * + * Side effects: + * Variables are deleted and trace procedures are invoked, if + * any are declared. + * + *---------------------------------------------------------------------- + */ + +void +TclDeleteCompiledLocalVars(iPtr, framePtr) + Interp *iPtr; /* Interpreter to which variables belong. */ + CallFrame *framePtr; /* Procedure call frame containing + * compiler-assigned local variables to + * delete. */ +{ + register Var *varPtr; + int flags; /* Flags passed to trace procedures. */ + Var *linkPtr; + ActiveVarTrace *activePtr; + int numLocals, i; + + flags = TCL_TRACE_UNSETS; + numLocals = framePtr->numCompiledLocals; + varPtr = framePtr->compiledLocals; + for (i = 0; i < numLocals; i++) { + /* + * For global/upvar variables referenced in procedures, decrement + * the reference count on the variable referred to, and free + * the referenced variable if it's no longer needed. Don't delete + * the hash entry for the other variable if it's in the same table + * as us: this will happen automatically later on. + */ + + if (TclIsVarLink(varPtr)) { + linkPtr = varPtr->value.linkPtr; + linkPtr->refCount--; + if ((linkPtr->refCount == 0) && TclIsVarUndefined(linkPtr) + && (linkPtr->tracePtr == NULL) + && (linkPtr->flags & VAR_IN_HASHTABLE)) { + if (linkPtr->hPtr == NULL) { + ckfree((char *) linkPtr); + } else { + Tcl_DeleteHashEntry(linkPtr->hPtr); + ckfree((char *) linkPtr); + } + } + } + + /* + * Invoke traces on the variable that is being deleted. Then delete + * the variable's trace records. + */ + + if (varPtr->tracePtr != NULL) { + (void) CallTraces(iPtr, (Var *) NULL, varPtr, + varPtr->name, (char *) NULL, flags); + while (varPtr->tracePtr != NULL) { + VarTrace *tracePtr = varPtr->tracePtr; + varPtr->tracePtr = tracePtr->nextPtr; + ckfree((char *) tracePtr); + } + for (activePtr = iPtr->activeTracePtr; activePtr != NULL; + activePtr = activePtr->nextPtr) { + if (activePtr->varPtr == varPtr) { + activePtr->nextTracePtr = NULL; + } + } + } + + /* + * Now if the variable is an array, delete its element hash table. + * Otherwise, if it's a scalar variable, decrement the ref count + * of its value. + */ + + if (TclIsVarArray(varPtr) && (varPtr->value.tablePtr != NULL)) { + DeleteArray(iPtr, varPtr->name, varPtr, flags); + } + if (TclIsVarScalar(varPtr) && (varPtr->value.objPtr != NULL)) { + TclDecrRefCount(varPtr->value.objPtr); + varPtr->value.objPtr = NULL; + } + varPtr->hPtr = NULL; + varPtr->tracePtr = NULL; + TclSetVarUndefined(varPtr); + TclSetVarScalar(varPtr); + varPtr++; + } +} + +/* + *---------------------------------------------------------------------- + * + * DeleteArray -- + * + * This procedure is called to free up everything in an array + * variable. It's the caller's responsibility to make sure + * that the array is no longer accessible before this procedure + * is called. + * + * Results: + * None. + * + * Side effects: + * All storage associated with varPtr's array elements is deleted + * (including the array's hash table). Deletion trace procedures for + * array elements are invoked, then deleted. Any pending traces for + * array elements are also deleted. + * + *---------------------------------------------------------------------- + */ + +static void +DeleteArray(iPtr, arrayName, varPtr, flags) + Interp *iPtr; /* Interpreter containing array. */ + char *arrayName; /* Name of array (used for trace + * callbacks). */ + Var *varPtr; /* Pointer to variable structure. */ + int flags; /* Flags to pass to CallTraces: + * TCL_TRACE_UNSETS and sometimes + * TCL_INTERP_DESTROYED, + * TCL_NAMESPACE_ONLY, or + * TCL_GLOBAL_ONLY. */ +{ + Tcl_HashSearch search; + register Tcl_HashEntry *hPtr; + register Var *elPtr; + ActiveVarTrace *activePtr; + Tcl_Obj *objPtr; + + DeleteSearches(varPtr); + for (hPtr = Tcl_FirstHashEntry(varPtr->value.tablePtr, &search); + hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) { + elPtr = (Var *) Tcl_GetHashValue(hPtr); + if (TclIsVarScalar(elPtr) && (elPtr->value.objPtr != NULL)) { + objPtr = elPtr->value.objPtr; + TclDecrRefCount(objPtr); + elPtr->value.objPtr = NULL; + } + elPtr->hPtr = NULL; + if (elPtr->tracePtr != NULL) { + elPtr->flags &= ~VAR_TRACE_ACTIVE; + (void) CallTraces(iPtr, (Var *) NULL, elPtr, arrayName, + Tcl_GetHashKey(varPtr->value.tablePtr, hPtr), flags); + while (elPtr->tracePtr != NULL) { + VarTrace *tracePtr = elPtr->tracePtr; + elPtr->tracePtr = tracePtr->nextPtr; + ckfree((char *) tracePtr); + } + for (activePtr = iPtr->activeTracePtr; activePtr != NULL; + activePtr = activePtr->nextPtr) { + if (activePtr->varPtr == elPtr) { + activePtr->nextTracePtr = NULL; + } + } + } + TclSetVarUndefined(elPtr); + TclSetVarScalar(elPtr); + if (elPtr->refCount == 0) { + ckfree((char *) elPtr); /* element Vars are VAR_IN_HASHTABLE */ + } + } + Tcl_DeleteHashTable(varPtr->value.tablePtr); + ckfree((char *) varPtr->value.tablePtr); +} + +/* + *---------------------------------------------------------------------- + * + * CleanupVar -- + * + * This procedure is called when it looks like it may be OK to free up + * a variable's storage. If the variable is in a hashtable, its Var + * structure and hash table entry will be freed along with those of its + * containing array, if any. This procedure is called, for example, + * when a trace on a variable deletes a variable. + * + * Results: + * None. + * + * Side effects: + * If the variable (or its containing array) really is dead and in a + * hashtable, then its Var structure, and possibly its hash table + * entry, is freed up. + * + *---------------------------------------------------------------------- + */ + +static void +CleanupVar(varPtr, arrayPtr) + Var *varPtr; /* Pointer to variable that may be a + * candidate for being expunged. */ + Var *arrayPtr; /* Array that contains the variable, or + * NULL if this variable isn't an array + * element. */ +{ + if (TclIsVarUndefined(varPtr) && (varPtr->refCount == 0) + && (varPtr->tracePtr == NULL) + && (varPtr->flags & VAR_IN_HASHTABLE)) { + if (varPtr->hPtr != NULL) { + Tcl_DeleteHashEntry(varPtr->hPtr); + } + ckfree((char *) varPtr); + } + if (arrayPtr != NULL) { + if (TclIsVarUndefined(arrayPtr) && (arrayPtr->refCount == 0) + && (arrayPtr->tracePtr == NULL) + && (arrayPtr->flags & VAR_IN_HASHTABLE)) { + if (arrayPtr->hPtr != NULL) { + Tcl_DeleteHashEntry(arrayPtr->hPtr); + } + ckfree((char *) arrayPtr); + } + } +} +/* + *---------------------------------------------------------------------- + * + * VarErrMsg -- + * + * Generate a reasonable error message describing why a variable + * operation failed. + * + * Results: + * None. + * + * Side effects: + * Interp->result is reset to hold a message identifying the + * variable given by part1 and part2 and describing why the + * variable operation failed. + * + *---------------------------------------------------------------------- + */ + +static void +VarErrMsg(interp, part1, part2, operation, reason) + Tcl_Interp *interp; /* Interpreter in which to record message. */ + char *part1, *part2; /* Variable's two-part name. */ + char *operation; /* String describing operation that failed, + * e.g. "read", "set", or "unset". */ + char *reason; /* String describing why operation failed. */ +{ + Tcl_ResetResult(interp); + Tcl_AppendResult(interp, "can't ", operation, " \"", part1, + (char *) NULL); + if (part2 != NULL) { + Tcl_AppendResult(interp, "(", part2, ")", (char *) NULL); + } + Tcl_AppendResult(interp, "\": ", reason, (char *) NULL); +} |