From 2226bec6cf911febed6c3ab9e80527ca71ba4be4 Mon Sep 17 00:00:00 2001 From: dgp Date: Fri, 14 Dec 2012 17:47:55 +0000 Subject: Various bits of cleanup, efficiencies, and comment documentation in tclVar.c --- generic/tclVar.c | 111 +++++++++++++++++++++++++++---------------------------- 1 file changed, 54 insertions(+), 57 deletions(-) diff --git a/generic/tclVar.c b/generic/tclVar.c index aaf1cb9..7622675 100644 --- a/generic/tclVar.c +++ b/generic/tclVar.c @@ -47,6 +47,13 @@ static inline void CleanupVar(Var *varPtr, Var *arrayPtr); #define VarHashGetValue(hPtr) \ ((Var *) ((char *)hPtr - TclOffset(VarInHash, entry))) +/* + * NOTE: VarHashCreateVar increments the recount of its key argument. + * All callers that will call Tcl_DecrRefCount on that argument must + * call Tcl_IncrRefCount on it before passing it in. This requirement + * can bubble up to callers of callers .... etc. + */ + static inline Var * VarHashCreateVar( TclVarHashTable *tablePtr, @@ -381,11 +388,12 @@ TclLookupVar( * address of array variable. Otherwise this * is set to NULL. */ { - Tcl_Obj *part1Ptr; Var *varPtr; + Tcl_Obj *part1Ptr = Tcl_NewStringObj(part1, -1); - part1Ptr = Tcl_NewStringObj(part1, -1); - Tcl_IncrRefCount(part1Ptr); + if (createPart1) { + Tcl_IncrRefCount(part1Ptr); + } varPtr = TclObjLookupVar(interp, part1Ptr, part2, flags, msg, createPart1, createPart2, arrayPtrPtr); @@ -430,6 +438,8 @@ TclLookupVar( * are 1. The object part1Ptr is converted to one of localVarNameType, * tclNsVarNameType or tclParsedVarNameType and caches as much of the * lookup as it can. + * When createPart1 is 1, callers must IncrRefCount part1Ptr if they + * plan to DecrRefCount it. * *---------------------------------------------------------------------- */ @@ -458,14 +468,11 @@ TclObjLookupVar( * address of array variable. Otherwise this * is set to NULL. */ { - Tcl_Obj *part2Ptr; + Tcl_Obj *part2Ptr = NULL; Var *resPtr; if (part2) { part2Ptr = Tcl_NewStringObj(part2, -1); - Tcl_IncrRefCount(part2Ptr); - } else { - part2Ptr = NULL; } resPtr = TclObjLookupVarEx(interp, part1Ptr, part2Ptr, @@ -840,6 +847,7 @@ TclObjLookupVarEx( * * Side effects: * A new hashtable entry may be created if create is 1. + * Callers must Incr varNamePtr if they plan to Decr it if create is 1. * *---------------------------------------------------------------------- */ @@ -1277,15 +1285,10 @@ Tcl_GetVar2Ex( int flags) /* OR-ed combination of TCL_GLOBAL_ONLY, and * TCL_LEAVE_ERR_MSG bits. */ { - Tcl_Obj *part1Ptr, *part2Ptr, *resPtr; + Tcl_Obj *resPtr, *part2Ptr = NULL, *part1Ptr = Tcl_NewStringObj(part1, -1); - part1Ptr = Tcl_NewStringObj(part1, -1); - Tcl_IncrRefCount(part1Ptr); if (part2) { part2Ptr = Tcl_NewStringObj(part2, -1); - Tcl_IncrRefCount(part2Ptr); - } else { - part2Ptr = NULL; } resPtr = Tcl_ObjGetVar2(interp, part1Ptr, part2Ptr, flags); @@ -1566,18 +1569,8 @@ Tcl_SetVar2( * TCL_APPEND_VALUE, TCL_LIST_ELEMENT, or * TCL_LEAVE_ERR_MSG. */ { - register Tcl_Obj *valuePtr; - Tcl_Obj *varValuePtr; - - /* - * Create an object holding the variable's new value and use Tcl_SetVar2Ex - * to actually set the variable. - */ - - valuePtr = Tcl_NewStringObj(newValue, -1); - Tcl_IncrRefCount(valuePtr); - varValuePtr = Tcl_SetVar2Ex(interp, part1, part2, valuePtr, flags); - Tcl_DecrRefCount(valuePtr); + Tcl_Obj *varValuePtr = Tcl_SetVar2Ex(interp, part1, part2, + Tcl_NewStringObj(newValue, -1), flags); if (varValuePtr == NULL) { return NULL; @@ -1637,15 +1630,12 @@ Tcl_SetVar2Ex( * TCL_APPEND_VALUE, TCL_LIST_ELEMENT or * TCL_LEAVE_ERR_MSG. */ { - Tcl_Obj *part1Ptr, *part2Ptr, *resPtr; + Tcl_Obj *resPtr, *part2Ptr = NULL, *part1Ptr = Tcl_NewStringObj(part1, -1); - part1Ptr = Tcl_NewStringObj(part1, -1); Tcl_IncrRefCount(part1Ptr); if (part2) { part2Ptr = Tcl_NewStringObj(part2, -1); Tcl_IncrRefCount(part2Ptr); - } else { - part2Ptr = NULL; } resPtr = Tcl_ObjSetVar2(interp, part1Ptr, part2Ptr, newValuePtr, flags); @@ -1678,6 +1668,7 @@ Tcl_SetVar2Ex( * 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. + * Callers must Incr part1Ptr if they plan to Decr it. * *---------------------------------------------------------------------- */ @@ -1965,6 +1956,7 @@ TclPtrSetVar( * 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. + * Callers must Incr part1Ptr if they plan to Decr it. * *---------------------------------------------------------------------- */ @@ -2047,8 +2039,7 @@ TclPtrIncrObjVar( * variable, or -1. Only used when part1Ptr is * NULL. */ { - register Tcl_Obj *varValuePtr, *newValuePtr = NULL; - int duplicated, code; + register Tcl_Obj *varValuePtr; if (TclIsVarInHash(varPtr)) { VarHashRefCount(varPtr)++; @@ -2062,19 +2053,33 @@ TclPtrIncrObjVar( varValuePtr = Tcl_NewIntObj(0); } if (Tcl_IsShared(varValuePtr)) { - duplicated = 1; + /* Copy on write */ varValuePtr = Tcl_DuplicateObj(varValuePtr); + + if (TCL_OK == TclIncrObj(interp, varValuePtr, incrPtr)) { + return TclPtrSetVar(interp, varPtr, arrayPtr, part1Ptr, part2Ptr, + varValuePtr, flags, index); + } else { + Tcl_DecrRefCount(varValuePtr); + return NULL; + } } else { - duplicated = 0; - } - code = TclIncrObj(interp, varValuePtr, incrPtr); - if (code == TCL_OK) { - newValuePtr = TclPtrSetVar(interp, varPtr, arrayPtr, part1Ptr, - part2Ptr, varValuePtr, flags, index); - } else if (duplicated) { - Tcl_DecrRefCount(varValuePtr); + /* Unshared - can Incr in place */ + if (TCL_OK == TclIncrObj(interp, varValuePtr, incrPtr)) { + + /* + * This seems dumb to write the incremeted value into the var + * after we just adjusted the value in place, but the spec for + * [incr] requires that write traces fire, and making this call + * is the way to make that happen. + */ + + return TclPtrSetVar(interp, varPtr, arrayPtr, part1Ptr, part2Ptr, + varValuePtr, flags, index); + } else { + return NULL; + } } - return newValuePtr; } /* @@ -2143,13 +2148,10 @@ Tcl_UnsetVar2( * TCL_LEAVE_ERR_MSG. */ { int result; - Tcl_Obj *part1Ptr, *part2Ptr = NULL; + Tcl_Obj *part2Ptr = NULL, *part1Ptr = Tcl_NewStringObj(part1, -1); - part1Ptr = Tcl_NewStringObj(part1, -1); - Tcl_IncrRefCount(part1Ptr); if (part2) { part2Ptr = Tcl_NewStringObj(part2, -1); - Tcl_IncrRefCount(part2Ptr); } /* @@ -3318,6 +3320,7 @@ Tcl_ArrayObjCmd( * * Side effects: * A variable will be created if one does not already exist. + * Callers must Incr arrayNameObj if they pland to Decr it. * *---------------------------------------------------------------------- */ @@ -3485,6 +3488,8 @@ TclArraySet( * 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. + * Callers must Incr myNamePtr if they plan to Decr it. + * Callers must Incr otherP1Ptr if they plan to Decr it. * *---------------------------------------------------------------------- */ @@ -3592,14 +3597,12 @@ TclPtrMakeUpvar( int index) /* If the variable to be linked is an indexed * scalar, this is its index. Otherwise, -1 */ { - Tcl_Obj *myNamePtr; + Tcl_Obj *myNamePtr = NULL; int result; if (myName) { myNamePtr = Tcl_NewStringObj(myName, -1); Tcl_IncrRefCount(myNamePtr); - } else { - myNamePtr = NULL; } result = TclPtrObjMakeUpvar(interp, otherPtr, myNamePtr, myFlags, index); if (myNamePtr) { @@ -3608,6 +3611,8 @@ TclPtrMakeUpvar( return result; } +/* Callers must Incr myNamePtr if they plan to Decr it. */ + int TclPtrObjMakeUpvar( Tcl_Interp *interp, /* Interpreter containing variables. Used for @@ -4425,7 +4430,6 @@ TclDeleteNamespaceVars( for (varPtr = VarHashFirstVar(tablePtr, &search); varPtr != NULL; varPtr = VarHashFirstVar(tablePtr, &search)) { Tcl_Obj *objPtr = Tcl_NewObj(); - Tcl_IncrRefCount(objPtr); VarHashRefCount(varPtr)++; /* Make sure we get to remove from * hash. */ @@ -4689,15 +4693,10 @@ TclVarErrMsg( * e.g. "read", "set", or "unset". */ const char *reason) /* String describing why operation failed. */ { - Tcl_Obj *part1Ptr = NULL, *part2Ptr = NULL; + Tcl_Obj *part2Ptr = NULL, *part1Ptr = Tcl_NewStringObj(part1, -1); - part1Ptr = Tcl_NewStringObj(part1, -1); - Tcl_IncrRefCount(part1Ptr); if (part2) { part2Ptr = Tcl_NewStringObj(part2, -1); - Tcl_IncrRefCount(part2Ptr); - } else { - part2 = NULL; } TclObjVarErrMsg(interp, part1Ptr, part2Ptr, operation, reason, -1); @@ -4965,7 +4964,6 @@ Tcl_FindNamespaceVar( Tcl_Obj *namePtr = Tcl_NewStringObj(name, -1); Tcl_Var var; - Tcl_IncrRefCount(namePtr); var = ObjFindNamespaceVar(interp, namePtr, contextNsPtr, flags); Tcl_DecrRefCount(namePtr); return var; @@ -5060,7 +5058,6 @@ ObjFindNamespaceVar( varPtr = NULL; if (simpleName != name) { simpleNamePtr = Tcl_NewStringObj(simpleName, -1); - Tcl_IncrRefCount(simpleNamePtr); } else { simpleNamePtr = namePtr; } -- cgit v0.12