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authormig <mig>2013-01-13 23:15:10 (GMT)
committermig <mig>2013-01-13 23:15:10 (GMT)
commitd64b6707b4b91c88d56b0147c0237411f47caa39 (patch)
tree90a09cfd344eac5623521d4cf3a4d91385da414f /generic/tclVar.c
parent7d3155c6e360cfbc4c9d6e98244622435eb470b9 (diff)
parent2226bec6cf911febed6c3ab9e80527ca71ba4be4 (diff)
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Various bits of cleanup, efficiencies, and comment documentation in tclVar.c (from mig-review)
Diffstat (limited to 'generic/tclVar.c')
-rw-r--r--generic/tclVar.c111
1 files 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;
}