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authordkf <donal.k.fellows@manchester.ac.uk>2013-09-27 10:29:43 (GMT)
committerdkf <donal.k.fellows@manchester.ac.uk>2013-09-27 10:29:43 (GMT)
commita5a2f896bb91053061b5a83f09cb0778c3b53e3b (patch)
tree16ec0b14f5357ad7601ebefaf5c1e71465d39eba /generic
parent790f8f7114d0cc7b44cbaddc66e36c877c9c55b6 (diff)
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[219226]: Rewrote how ::env is synchronized to the environment so it no longer
smashes the array or its elements flat, This affects traces on env, links to env, and iterations over env: it makes them work as naïvely expected.
Diffstat (limited to 'generic')
-rw-r--r--generic/tclEnv.c81
-rw-r--r--generic/tclInt.h2
-rw-r--r--generic/tclVar.c47
3 files changed, 114 insertions, 16 deletions
diff --git a/generic/tclEnv.c b/generic/tclEnv.c
index b5ae6ea..6a21947 100644
--- a/generic/tclEnv.c
+++ b/generic/tclEnv.c
@@ -76,36 +76,56 @@ TclSetupEnv(
Tcl_Interp *interp) /* Interpreter whose "env" array is to be
* managed. */
{
+ Var *varPtr, *arrayPtr;
+ Tcl_Obj *varNamePtr;
Tcl_DString envString;
- char *p1, *p2;
- int i;
+ Tcl_HashTable namesHash;
+ Tcl_HashEntry *hPtr;
+ Tcl_HashSearch search;
/*
* Synchronize the values in the environ array with the contents of the
* Tcl "env" variable. To do this:
- * 1) Remove the trace that fires when the "env" var is unset.
- * 2) Unset the "env" variable.
- * 3) If there are no environ variables, create an empty "env" array.
- * Otherwise populate the array with current values.
- * 4) Add a trace that synchronizes the "env" array.
+ * 1) Remove the trace that fires when the "env" var is updated.
+ * 2) Find the existing contents of the "env", storing in a hash table.
+ * 3) Create/update elements for each environ variable, removing
+ * elements from the hash table as we go.
+ * 4) Remove the elements for each remaining entry in the hash table,
+ * which must have existed before yet have no analog in the environ
+ * variable.
+ * 5) Add a trace that synchronizes the "env" array.
*/
Tcl_UntraceVar2(interp, "env", NULL,
TCL_GLOBAL_ONLY | TCL_TRACE_WRITES | TCL_TRACE_UNSETS |
TCL_TRACE_READS | TCL_TRACE_ARRAY, EnvTraceProc, NULL);
- Tcl_UnsetVar2(interp, "env", NULL, TCL_GLOBAL_ONLY);
+ /*
+ * Find out what elements are currently in the global env array.
+ */
- if (environ[0] == NULL) {
- Tcl_Obj *varNamePtr;
+ TclNewLiteralStringObj(varNamePtr, "env");
+ Tcl_IncrRefCount(varNamePtr);
+ Tcl_InitObjHashTable(&namesHash);
+ varPtr = TclObjLookupVarEx(interp, varNamePtr, NULL, TCL_GLOBAL_ONLY,
+ /*msg*/ 0, /*createPart1*/ 0, /*createPart2*/ 0, &arrayPtr);
+ TclFindArrayPtrElements(varPtr, &namesHash);
+
+ /*
+ * Go through the environment array and transfer its values into Tcl. At
+ * the same time, remove those elements we add/update from the hash table
+ * of existing elements, so that after this part processes, that table
+ * will hold just the parts to remove.
+ */
+
+ if (environ[0] != NULL) {
+ int i;
- TclNewLiteralStringObj(varNamePtr, "env");
- Tcl_IncrRefCount(varNamePtr);
- TclArraySet(interp, varNamePtr, NULL);
- Tcl_DecrRefCount(varNamePtr);
- } else {
Tcl_MutexLock(&envMutex);
for (i = 0; environ[i] != NULL; i++) {
+ Tcl_Obj *obj1, *obj2;
+ char *p1, *p2;
+
p1 = Tcl_ExternalToUtfDString(NULL, environ[i], -1, &envString);
p2 = strchr(p1, '=');
if (p2 == NULL) {
@@ -119,12 +139,41 @@ TclSetupEnv(
}
p2++;
p2[-1] = '\0';
- Tcl_SetVar2(interp, "env", p1, p2, TCL_GLOBAL_ONLY);
+ obj1 = Tcl_NewStringObj(p1, -1);
+ obj2 = Tcl_NewStringObj(p2, -1);
Tcl_DStringFree(&envString);
+
+ Tcl_IncrRefCount(obj1);
+ Tcl_IncrRefCount(obj2);
+ Tcl_ObjSetVar2(interp, varNamePtr, obj1, obj2, TCL_GLOBAL_ONLY);
+ hPtr = Tcl_FindHashEntry(&namesHash, obj1);
+ if (hPtr != NULL) {
+ Tcl_DeleteHashEntry(hPtr);
+ }
+ Tcl_DecrRefCount(obj1);
+ Tcl_DecrRefCount(obj2);
}
Tcl_MutexUnlock(&envMutex);
}
+ /*
+ * Delete those elements that existed in the array but which had no
+ * counterparts in the environment array.
+ */
+
+ for (hPtr=Tcl_FirstHashEntry(&namesHash, &search); hPtr!=NULL;
+ hPtr=Tcl_NextHashEntry(&search)) {
+ Tcl_Obj *elemName = Tcl_GetHashValue(hPtr);
+
+ TclObjUnsetVar2(interp, varNamePtr, elemName, TCL_GLOBAL_ONLY);
+ }
+ Tcl_DeleteHashTable(&namesHash);
+ Tcl_DecrRefCount(varNamePtr);
+
+ /*
+ * Re-establish the trace.
+ */
+
Tcl_TraceVar2(interp, "env", NULL,
TCL_GLOBAL_ONLY | TCL_TRACE_WRITES | TCL_TRACE_UNSETS |
TCL_TRACE_READS | TCL_TRACE_ARRAY, EnvTraceProc, NULL);
diff --git a/generic/tclInt.h b/generic/tclInt.h
index 380284f..feea6dd 100644
--- a/generic/tclInt.h
+++ b/generic/tclInt.h
@@ -3857,6 +3857,8 @@ MODULE_SCOPE int TclPtrUnsetVar(Tcl_Interp *interp, Var *varPtr,
Tcl_Obj *part2Ptr, const int flags,
int index);
MODULE_SCOPE void TclInvalidateNsPath(Namespace *nsPtr);
+MODULE_SCOPE void TclFindArrayPtrElements(Var *arrayPtr,
+ Tcl_HashTable *tablePtr);
/*
* The new extended interface to the variable traces.
diff --git a/generic/tclVar.c b/generic/tclVar.c
index af1a563..4694cd8 100644
--- a/generic/tclVar.c
+++ b/generic/tclVar.c
@@ -3850,6 +3850,53 @@ ArrayNamesCmd(
/*
*----------------------------------------------------------------------
*
+ * TclFindArrayPtrElements --
+ *
+ * Fill out a hash table (which *must* use Tcl_Obj* keys) with an entry
+ * for each existing element of the given array. The provided hash table
+ * is assumed to be initially empty.
+ *
+ * Result:
+ * none
+ *
+ * Side effects:
+ * The keys of the array gain an extra reference. The supplied hash table
+ * has elements added to it.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+TclFindArrayPtrElements(
+ Var *arrayPtr,
+ Tcl_HashTable *tablePtr)
+{
+ Var *varPtr;
+ Tcl_HashSearch search;
+
+ if ((arrayPtr == NULL) || !TclIsVarArray(arrayPtr)
+ || TclIsVarUndefined(arrayPtr)) {
+ return;
+ }
+
+ for (varPtr=VarHashFirstVar(arrayPtr->value.tablePtr, &search);
+ varPtr!=NULL ; varPtr=VarHashNextVar(&search)) {
+ Tcl_HashEntry *hPtr;
+ Tcl_Obj *nameObj;
+ int dummy;
+
+ if (TclIsVarUndefined(varPtr)) {
+ continue;
+ }
+ nameObj = VarHashGetKey(varPtr);
+ hPtr = Tcl_CreateHashEntry(tablePtr, (char *) nameObj, &dummy);
+ Tcl_SetHashValue(hPtr, nameObj);
+ }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
* ArraySetCmd --
*
* This object-based function is invoked to process the "array set" Tcl