* generic/tclInt.h:

	* generic/tclExecute.c: Tcl-stack reform, [Patch 1701202]

1 files changed, 18 insertions, 8 deletions

diff --git a/generic/tclInt.h b/generic/tclInt.h
index ec0fd19..b9c8f3a 100644
--- a/generic/tclInt.h
+++ b/generic/tclInt.h
@@ -12,7 +12,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclInt.h,v 1.311 2007/05/30 18:12:58 dgp Exp $
+ * RCS: @(#) $Id: tclInt.h,v 1.312 2007/06/05 17:50:56 msofer Exp $
  */
 
 #ifndef _TCLINT
@@ -1183,20 +1183,30 @@ typedef int (CompileHookProc) (Tcl_Interp *interp,
 	struct CompileEnv *compEnvPtr, ClientData clientData);
 
 /*
+ * The data structure for a (linked list of) execution stacks.
+ */
+
+typedef struct ExecStack {
+    struct ExecStack *prevPtr;
+    struct ExecStack *nextPtr;
+    Tcl_Obj **markerPtr;
+    Tcl_Obj **endPtr;
+    Tcl_Obj **tosPtr;
+    Tcl_Obj *stackWords[1];
+} ExecStack;
+
+
+/*
  * The data structure defining the execution environment for ByteCode's.
  * There is one ExecEnv structure per Tcl interpreter. It holds the evaluation
  * stack that holds command operands and results. The stack grows towards
- * increasing addresses. The "stackTop" member is cached by TclExecuteByteCode
- * in a local variable: it must be set before calling TclExecuteByteCode and
- * will be restored by TclExecuteByteCode before it returns.
+ * increasing addresses. The member stackPtr points to the stackItems of the
+ * currently active execution stack.
  */
 
 typedef struct ExecEnv {
-    Tcl_Obj **stackPtr;		/* Points to the first item in the evaluation
+    ExecStack *execStackPtr;	/* Points to the first item in the evaluation
 				 * stack on the heap. */
-    Tcl_Obj **tosPtr;		/* Points to current top of stack;
-				 * (stackPtr-1) when the stack is empty. */
-    Tcl_Obj **endPtr;		/* Points to last usable item in stack. */
     Tcl_Obj *constants[2];	/* Pointers to constant "0" and "1" objs. */
 } ExecEnv;