diff options
Diffstat (limited to 'generic/tclVar.c')
| -rw-r--r-- | generic/tclVar.c | 483 |
1 files changed, 432 insertions, 51 deletions
diff --git a/generic/tclVar.c b/generic/tclVar.c index ca92803..cafa6a3 100644 --- a/generic/tclVar.c +++ b/generic/tclVar.c @@ -165,6 +165,18 @@ typedef struct ArraySearch { } ArraySearch; /* + * TIP #508: [array default] + * + * The following structure extends the regular TclVarHashTable used by array + * variables to store their optional default value. + */ + +typedef struct ArrayVarHashTable { + TclVarHashTable table; + Tcl_Obj *defaultObj; +} ArrayVarHashTable; + +/* * Forward references to functions defined later in this file: */ @@ -198,6 +210,16 @@ static void UnsetVarStruct(Var *varPtr, Var *arrayPtr, Tcl_Obj *part2Ptr, int flags, int index); /* + * TIP #508: [array default] + */ + +static int ArrayDefaultCmd(ClientData clientData, + Tcl_Interp *interp, int objc, + Tcl_Obj *const objv[]); +static void DeleteArrayVar(Var *arrayPtr); +static void SetArrayDefault(Var *arrayPtr, Tcl_Obj *defaultObj); + +/* * Functions defined in this file that may be exported in the future for use * by the bytecode compiler and engine or to the public interface. */ @@ -236,7 +258,6 @@ static const Tcl_ObjType tclParsedVarNameType = { "parsedVarName", FreeParsedVarName, DupParsedVarName, NULL, NULL }; - Var * TclVarHashCreateVar( @@ -1019,8 +1040,6 @@ TclLookupArrayElement( { int isNew; Var *varPtr; - TclVarHashTable *tablePtr; - Namespace *nsPtr; /* * We're dealing with an array element. Make sure the variable is an array @@ -1053,16 +1072,7 @@ TclLookupArrayElement( return NULL; } - TclSetVarArray(arrayPtr); - tablePtr = ckalloc(sizeof(TclVarHashTable)); - arrayPtr->value.tablePtr = tablePtr; - - if (TclIsVarInHash(arrayPtr) && TclGetVarNsPtr(arrayPtr)) { - nsPtr = TclGetVarNsPtr(arrayPtr); - } else { - nsPtr = NULL; - } - TclInitVarHashTable(arrayPtr->value.tablePtr, nsPtr); + TclInitArrayVar(arrayPtr); } else if (!TclIsVarArray(arrayPtr)) { if (flags & TCL_LEAVE_ERR_MSG) { TclObjVarErrMsg(interp, arrayNamePtr, elNamePtr, msg, needArray, @@ -1412,6 +1422,28 @@ TclPtrGetVarIdx( return varPtr->value.objPtr; } + /* + * Return the array default value if any. + */ + + if (arrayPtr && TclIsVarArray(arrayPtr) && TclGetArrayDefault(arrayPtr)) { + return TclGetArrayDefault(arrayPtr); + } + if (TclIsVarArrayElement(varPtr) && !arrayPtr) { + /* + * UGLY! Peek inside the implementation of things. This lets us get + * the default of an array even when we've been [upvar]ed to just an + * element of the array. + */ + + ArrayVarHashTable *avhtPtr = (ArrayVarHashTable *) + ((VarInHash *) varPtr)->entry.tablePtr; + + if (avhtPtr->defaultObj) { + return avhtPtr->defaultObj; + } + } + if (flags & TCL_LEAVE_ERR_MSG) { if (TclIsVarUndefined(varPtr) && arrayPtr && !TclIsVarUndefined(arrayPtr)) { @@ -1772,6 +1804,130 @@ TclPtrSetVar( /* *---------------------------------------------------------------------- * + * ListAppendInVar, StringAppendInVar -- + * + * Support functions for TclPtrSetVarIdx that implement various types of + * appending operations. + * + * Results: + * ListAppendInVar returns a Tcl result code (from the core list append + * operation). StringAppendInVar has no return value. + * + * Side effects: + * The variable or element of the array is updated. This may make the + * variable/element exist. Reference counts of values may be updated. + * + *---------------------------------------------------------------------- + */ + +static inline int +ListAppendInVar( + Tcl_Interp *interp, + Var *varPtr, + Var *arrayPtr, + Tcl_Obj *oldValuePtr, + Tcl_Obj *newValuePtr) +{ + if (oldValuePtr == NULL) { + /* + * No previous value. Check for defaults if there's an array we can + * ask this of. + */ + + if (arrayPtr) { + Tcl_Obj *defValuePtr = TclGetArrayDefault(arrayPtr); + + if (defValuePtr) { + oldValuePtr = Tcl_DuplicateObj(defValuePtr); + } + } + + if (oldValuePtr == NULL) { + /* + * No default. [lappend] semantics say this is like being an empty + * string. + */ + + TclNewObj(oldValuePtr); + } + varPtr->value.objPtr = oldValuePtr; + Tcl_IncrRefCount(oldValuePtr); /* Since var is referenced. */ + } else if (Tcl_IsShared(oldValuePtr)) { + varPtr->value.objPtr = Tcl_DuplicateObj(oldValuePtr); + TclDecrRefCount(oldValuePtr); + oldValuePtr = varPtr->value.objPtr; + Tcl_IncrRefCount(oldValuePtr); /* Since var is referenced. */ + } + + return Tcl_ListObjAppendElement(interp, oldValuePtr, newValuePtr); +} + +static inline void +StringAppendInVar( + Var *varPtr, + Var *arrayPtr, + Tcl_Obj *oldValuePtr, + Tcl_Obj *newValuePtr) +{ + /* + * If there was no previous value, either we use the array's default (if + * this is an array with a default at all) or we treat this as a simple + * set. + */ + + if (oldValuePtr == NULL) { + if (arrayPtr) { + Tcl_Obj *defValuePtr = TclGetArrayDefault(arrayPtr); + + if (defValuePtr) { + /* + * This is *almost* the same as the shared path below, except + * that the original value reference in defValuePtr is not + * decremented. + */ + + Tcl_Obj *valuePtr = Tcl_DuplicateObj(defValuePtr); + + varPtr->value.objPtr = valuePtr; + TclContinuationsCopy(valuePtr, defValuePtr); + Tcl_IncrRefCount(valuePtr); + Tcl_AppendObjToObj(valuePtr, newValuePtr); + if (newValuePtr->refCount == 0) { + Tcl_DecrRefCount(newValuePtr); + } + return; + } + } + varPtr->value.objPtr = newValuePtr; + Tcl_IncrRefCount(newValuePtr); + return; + } + + /* + * We append newValuePtr's bytes but don't change its ref count. Unless + * the reference is shared, when we have to duplicate in order to be safe + * to modify at all. + */ + + if (Tcl_IsShared(oldValuePtr)) { /* Append to copy. */ + varPtr->value.objPtr = Tcl_DuplicateObj(oldValuePtr); + + TclContinuationsCopy(varPtr->value.objPtr, oldValuePtr); + + TclDecrRefCount(oldValuePtr); + oldValuePtr = varPtr->value.objPtr; + Tcl_IncrRefCount(oldValuePtr); /* Since var is ref */ + } + + Tcl_AppendObjToObj(oldValuePtr, newValuePtr); + if (newValuePtr->refCount == 0) { + Tcl_DecrRefCount(newValuePtr); + } +} + +/* + *---------------------------------------------------------------------- + * * TclPtrSetVarIdx -- * * This function is the same as Tcl_SetVar2Ex above, except that it @@ -1884,44 +2040,13 @@ TclPtrSetVarIdx( } if (flags & (TCL_APPEND_VALUE|TCL_LIST_ELEMENT)) { if (flags & TCL_LIST_ELEMENT) { /* Append list element. */ - if (oldValuePtr == NULL) { - TclNewObj(oldValuePtr); - varPtr->value.objPtr = oldValuePtr; - Tcl_IncrRefCount(oldValuePtr); /* Since var is referenced. */ - } else if (Tcl_IsShared(oldValuePtr)) { - varPtr->value.objPtr = Tcl_DuplicateObj(oldValuePtr); - TclDecrRefCount(oldValuePtr); - oldValuePtr = varPtr->value.objPtr; - Tcl_IncrRefCount(oldValuePtr); /* Since var is referenced. */ - } - result = Tcl_ListObjAppendElement(interp, oldValuePtr, + result = ListAppendInVar(interp, varPtr, arrayPtr, oldValuePtr, newValuePtr); if (result != TCL_OK) { goto earlyError; } } else { /* Append string. */ - /* - * We append newValuePtr's bytes but don't change its ref count. - */ - - if (oldValuePtr == NULL) { - varPtr->value.objPtr = newValuePtr; - Tcl_IncrRefCount(newValuePtr); - } else { - if (Tcl_IsShared(oldValuePtr)) { /* Append to copy. */ - varPtr->value.objPtr = Tcl_DuplicateObj(oldValuePtr); - - TclContinuationsCopy(varPtr->value.objPtr, oldValuePtr); - - TclDecrRefCount(oldValuePtr); - oldValuePtr = varPtr->value.objPtr; - Tcl_IncrRefCount(oldValuePtr); /* Since var is ref */ - } - Tcl_AppendObjToObj(oldValuePtr, newValuePtr); - if (newValuePtr->refCount == 0) { - Tcl_DecrRefCount(newValuePtr); - } - } + StringAppendInVar(varPtr, arrayPtr, oldValuePtr, newValuePtr); } } else if (newValuePtr != oldValuePtr) { /* @@ -4078,9 +4203,7 @@ ArraySetCmd( return TCL_ERROR; } } - TclSetVarArray(varPtr); - varPtr->value.tablePtr = ckalloc(sizeof(TclVarHashTable)); - TclInitVarHashTable(varPtr->value.tablePtr, TclGetVarNsPtr(varPtr)); + TclInitArrayVar(varPtr); return TCL_OK; } @@ -4360,6 +4483,7 @@ TclInitArrayCmd( { static const EnsembleImplMap arrayImplMap[] = { {"anymore", ArrayAnyMoreCmd, TclCompileBasic2ArgCmd, NULL, NULL, 0}, + {"default", ArrayDefaultCmd, TclCompileBasic2Or3ArgCmd, NULL, NULL, 0}, {"donesearch", ArrayDoneSearchCmd, TclCompileBasic2ArgCmd, NULL, NULL, 0}, {"exists", ArrayExistsCmd, TclCompileArrayExistsCmd, NULL, NULL, 0}, {"for", ArrayForObjCmd, TclCompileBasic3ArgCmd, ArrayForNRCmd, NULL, 0}, @@ -5550,8 +5674,7 @@ DeleteArray( TclClearVarNamespaceVar(elPtr); } - VarHashDeleteTable(varPtr->value.tablePtr); - ckfree(varPtr->value.tablePtr); + DeleteArrayVar(varPtr); } /* @@ -6467,6 +6590,264 @@ CompareVarKeys( return ((l1 == l2) && !memcmp(p1, p2, l1)); } +/*---------------------------------------------------------------------- + * + * ArrayDefaultCmd -- + * + * This function implements the 'array default' Tcl command. + * Refer to the user documentation for details on what it does. + * + * Results: + * Returns a standard Tcl result. + * + * Side effects: + * See the user documentation. + * + *---------------------------------------------------------------------- + */ + + /* ARGSUSED */ +static int +ArrayDefaultCmd( + ClientData clientData, /* Not used. */ + Tcl_Interp *interp, /* Current interpreter. */ + int objc, /* Number of arguments. */ + Tcl_Obj *const objv[]) /* Argument objects. */ +{ + static const char *const options[] = { + "get", "set", "exists", "unset", NULL + }; + enum options { OPT_GET, OPT_SET, OPT_EXISTS, OPT_UNSET }; + Tcl_Obj *arrayNameObj, *defaultValueObj; + Var *varPtr, *arrayPtr; + int isArray, option; + + /* + * Parse arguments. + */ + + if (objc != 3 && objc != 4) { + Tcl_WrongNumArgs(interp, 1, objv, "option arrayName ?value?"); + return TCL_ERROR; + } + if (Tcl_GetIndexFromObj(interp, objv[1], options, "option", + 0, &option) != TCL_OK) { + return TCL_ERROR; + } + + arrayNameObj = objv[2]; + + if (TCL_ERROR == LocateArray(interp, arrayNameObj, &varPtr, &isArray)) { + return TCL_ERROR; + } + + switch (option) { + case OPT_GET: + if (objc != 3) { + Tcl_WrongNumArgs(interp, 2, objv, "arrayName"); + return TCL_ERROR; + } + if (!varPtr || TclIsVarUndefined(varPtr) || !isArray) { + return NotArrayError(interp, arrayNameObj); + } + + defaultValueObj = TclGetArrayDefault(varPtr); + if (!defaultValueObj) { + /* Array default must exist. */ + Tcl_SetObjResult(interp, Tcl_NewStringObj( + "array has no default value", -1)); + Tcl_SetErrorCode(interp, "TCL", "READ", "ARRAY", "DEFAULT", NULL); + return TCL_ERROR; + } + Tcl_SetObjResult(interp, defaultValueObj); + return TCL_OK; + + case OPT_SET: + if (objc != 4) { + Tcl_WrongNumArgs(interp, 2, objv, "arrayName value"); + return TCL_ERROR; + } + + /* + * Attempt to create array if needed. + */ + varPtr = TclObjLookupVarEx(interp, arrayNameObj, NULL, + /*flags*/ TCL_LEAVE_ERR_MSG, /*msg*/ "array default set", + /*createPart1*/ 1, /*createPart2*/ 1, &arrayPtr); + if (varPtr == NULL) { + return TCL_ERROR; + } + if (arrayPtr) { + /* + * Not a valid array name. + */ + + CleanupVar(varPtr, arrayPtr); + TclObjVarErrMsg(interp, arrayNameObj, NULL, "array default set", + needArray, -1); + Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "VARNAME", + TclGetString(arrayNameObj), NULL); + return TCL_ERROR; + } + if (!TclIsVarArray(varPtr) && !TclIsVarUndefined(varPtr)) { + /* + * Not an array. + */ + + TclObjVarErrMsg(interp, arrayNameObj, NULL, "array default set", + needArray, -1); + Tcl_SetErrorCode(interp, "TCL", "WRITE", "ARRAY", NULL); + return TCL_ERROR; + } + + if (!TclIsVarArray(varPtr)) { + TclInitArrayVar(varPtr); + } + defaultValueObj = objv[3]; + SetArrayDefault(varPtr, defaultValueObj); + return TCL_OK; + + case OPT_EXISTS: + if (objc != 3) { + Tcl_WrongNumArgs(interp, 2, objv, "arrayName"); + return TCL_ERROR; + } + + /* + * Undefined variables (whether or not they have storage allocated) do + * not have defaults, and this is not an error case. + */ + + if (!varPtr || TclIsVarUndefined(varPtr)) { + Tcl_SetObjResult(interp, Tcl_NewBooleanObj(0)); + } else if (!isArray) { + return NotArrayError(interp, arrayNameObj); + } else { + defaultValueObj = TclGetArrayDefault(varPtr); + Tcl_SetObjResult(interp, Tcl_NewBooleanObj(!!defaultValueObj)); + } + return TCL_OK; + + case OPT_UNSET: + if (objc != 3) { + Tcl_WrongNumArgs(interp, 2, objv, "arrayName"); + return TCL_ERROR; + } + + if (varPtr && !TclIsVarUndefined(varPtr)) { + if (!isArray) { + return NotArrayError(interp, arrayNameObj); + } + SetArrayDefault(varPtr, NULL); + } + return TCL_OK; + } + + /* Unreached */ + return TCL_ERROR; +} + +/* + * Initialize array variable. + */ + +void +TclInitArrayVar( + Var *arrayPtr) +{ + ArrayVarHashTable *tablePtr = ckalloc(sizeof(ArrayVarHashTable)); + + /* + * Mark the variable as an array. + */ + + TclSetVarArray(arrayPtr); + + /* + * Regular TclVarHashTable initialization. + */ + + arrayPtr->value.tablePtr = (TclVarHashTable *) tablePtr; + TclInitVarHashTable(arrayPtr->value.tablePtr, TclGetVarNsPtr(arrayPtr)); + + /* + * Default value initialization. + */ + + tablePtr->defaultObj = NULL; +} + +/* + * Cleanup array variable. + */ + +static void +DeleteArrayVar( + Var *arrayPtr) +{ + ArrayVarHashTable *tablePtr = (ArrayVarHashTable *) + arrayPtr->value.tablePtr; + + /* + * Default value cleanup. + */ + + SetArrayDefault(arrayPtr, NULL); + + /* + * Regular TclVarHashTable cleanup. + */ + + VarHashDeleteTable(arrayPtr->value.tablePtr); + ckfree(tablePtr); +} + +/* + * Get array default value if any. + */ + +Tcl_Obj * +TclGetArrayDefault( + Var *arrayPtr) +{ + ArrayVarHashTable *tablePtr = (ArrayVarHashTable *) + arrayPtr->value.tablePtr; + + return tablePtr->defaultObj; +} + +/* + * Set/replace/unset array default value. + */ + +static void +SetArrayDefault( + Var *arrayPtr, + Tcl_Obj *defaultObj) +{ + ArrayVarHashTable *tablePtr = (ArrayVarHashTable *) + arrayPtr->value.tablePtr; + + /* + * Increment/decrement refcount twice to ensure that the object is shared, + * so that it doesn't get modified accidentally by the folling code: + * + * array default set v 1 + * lappend v(a) 2; # returns a new object {1 2} + * set v(b); # returns the original default object "1" + */ + + if (tablePtr->defaultObj) { + Tcl_DecrRefCount(tablePtr->defaultObj); + Tcl_DecrRefCount(tablePtr->defaultObj); + } + tablePtr->defaultObj = defaultObj; + if (tablePtr->defaultObj) { + Tcl_IncrRefCount(tablePtr->defaultObj); + Tcl_IncrRefCount(tablePtr->defaultObj); + } +} + /* * Local Variables: * mode: c |