* doc/interp.n: [3081184] TIP #378.

	* doc/tclvars.n: Performance fix for TIP #280.
	* generic/tclBasic.c:
	* generic/tclExecute.c:
	* generic/tclInt.h:
	* generic/tclInterp.c:
	* tests/info.test:
	* tests/interp.test:

4 files changed, 137 insertions, 17 deletions

diff --git a/generic/tclBasic.c b/generic/tclBasic.c
index fa63953..7fae8b3 100644
--- a/generic/tclBasic.c
+++ b/generic/tclBasic.c
@@ -16,7 +16,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclBasic.c,v 1.468 2010/10/20 20:52:26 ferrieux Exp $
+ * RCS: @(#) $Id: tclBasic.c,v 1.469 2010/11/15 21:34:54 andreas_kupries Exp $
  */
 
 #include "tclInt.h"
@@ -596,6 +596,15 @@ Tcl_CreateInterp(void)
     iPtr->resultSpace[0] = 0;
     iPtr->threadId = Tcl_GetCurrentThread();
 
+    /* TIP #378 */
+#ifdef TCL_INTERP_DEBUG_FRAME
+    iPtr->flags |= INTERP_DEBUG_FRAME;
+#else
+    if (getenv("TCL_INTERP_DEBUG_FRAME") != NULL) {
+        iPtr->flags |= INTERP_DEBUG_FRAME;
+    }
+#endif
+
     /*
      * Initialise the tables for variable traces and searches *before*
      * creating the global ns - so that the trace on errorInfo can be
diff --git a/generic/tclExecute.c b/generic/tclExecute.c
index a8b408e..884c7d5 100644
--- a/generic/tclExecute.c
+++ b/generic/tclExecute.c
@@ -14,7 +14,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclExecute.c,v 1.509 2010/10/20 20:52:28 ferrieux Exp $
+ * RCS: @(#) $Id: tclExecute.c,v 1.510 2010/11/15 21:34:54 andreas_kupries Exp $
  */
 
 #include "tclInt.h"
@@ -2120,7 +2120,9 @@ TEBCresume(
 	NRE_ASSERT(iPtr->cmdFramePtr == bcFramePtr);
 	NRE_ASSERT(TOP_CB(interp)->procPtr == TEBCreturn);
 	iPtr->cmdFramePtr = bcFramePtr->nextPtr;
-	TclArgumentBCRelease((Tcl_Interp *) iPtr, bcFramePtr);
+	if (iPtr->flags & INTERP_DEBUG_FRAME) {
+	    TclArgumentBCRelease((Tcl_Interp *) iPtr, bcFramePtr);
+	}
 	if (codePtr->flags & TCL_BYTECODE_RECOMPILE) {
 	    iPtr->flags |= ERR_ALREADY_LOGGED;
 	    codePtr->flags &= ~TCL_BYTECODE_RECOMPILE;
@@ -2797,8 +2799,10 @@ TEBCresume(
 	bcFramePtr->data.tebc.pc = (char *) pc;
 	iPtr->cmdFramePtr = bcFramePtr;
 
-	TclArgumentBCEnter((Tcl_Interp *) iPtr, objv, objc,
-		codePtr, bcFramePtr, pc - codePtr->codeStart);
+	if (iPtr->flags & INTERP_DEBUG_FRAME) {
+	    TclArgumentBCEnter((Tcl_Interp *) iPtr, objv, objc,
+		    codePtr, bcFramePtr, pc - codePtr->codeStart);
+	}
 
 	DECACHE_STACK_INFO();
 
diff --git a/generic/tclInt.h b/generic/tclInt.h
index c4ab6b3..218c40b 100644
--- a/generic/tclInt.h
+++ b/generic/tclInt.h
@@ -15,7 +15,7 @@
  * 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 1.485 2010/10/20 20:52:28 ferrieux Exp $
+ * RCS: @(#) $Id: tclInt.h,v 1.486 2010/11/15 21:34:54 andreas_kupries Exp $
  */
 
 #ifndef _TCLINT
@@ -2253,6 +2253,9 @@ typedef struct InterpList {
  * SAFE_INTERP:		Non zero means that the current interp is a safe
  *			interp (i.e. it has only the safe commands installed,
  *			less priviledge than a regular interp).
+ * INTERP_DEBUG_FRAME:	Used for switching on various extra interpreter
+ *			debug/info mechanisms (e.g. info frame eval/uplevel
+ *			tracing) which are performance intensive.
  * INTERP_TRACE_IN_PROGRESS: Non-zero means that an interp trace is currently
  *			active; so no further trace callbacks should be
  *			invoked.
@@ -2278,6 +2281,7 @@ typedef struct InterpList {
 
 #define DELETED				     1
 #define ERR_ALREADY_LOGGED		     4
+#define INTERP_DEBUG_FRAME		  0x10
 #define DONT_COMPILE_CMDS_INLINE	  0x20
 #define RAND_SEED_INITIALIZED		  0x40
 #define SAFE_INTERP			  0x80
diff --git a/generic/tclInterp.c b/generic/tclInterp.c
index e22133a..6ccde87 100644
--- a/generic/tclInterp.c
+++ b/generic/tclInterp.c
@@ -10,7 +10,7 @@
  * See the file "license.terms" for information on usage and redistribution
  * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclInterp.c,v 1.113 2010/08/22 18:53:26 nijtmans Exp $
+ * RCS: @(#) $Id: tclInterp.c,v 1.114 2010/11/15 21:34:54 andreas_kupries Exp $
  */
 
 #include "tclInt.h"
@@ -210,6 +210,9 @@ static int		SlaveBgerror(Tcl_Interp *interp,
 			    Tcl_Obj *const objv[]);
 static Tcl_Interp *	SlaveCreate(Tcl_Interp *interp, Tcl_Obj *pathPtr,
 			    int safe);
+static int		SlaveDebugCmd(Tcl_Interp *interp,
+			    Tcl_Interp *slaveInterp,
+			    int objc, Tcl_Obj *const objv[]);
 static int		SlaveEval(Tcl_Interp *interp, Tcl_Interp *slaveInterp,
 			    int objc, Tcl_Obj *const objv[]);
 static int		SlaveExpose(Tcl_Interp *interp,
@@ -561,16 +564,18 @@ Tcl_InterpObjCmd(
     int index;
     static const char *const options[] = {
 	"alias",	"aliases",	"bgerror",	"cancel",
-	"create",	"delete",	"eval",		"exists",
-	"expose",	"hide",		"hidden",	"issafe",
+	"create",	"debug",	"delete",
+	"eval",		"exists",	"expose",
+	"hide",		"hidden",	"issafe",
 	"invokehidden",	"limit",	"marktrusted",	"recursionlimit",
 	"slaves",	"share",	"target",	"transfer",
 	NULL
     };
     enum option {
 	OPT_ALIAS,	OPT_ALIASES,	OPT_BGERROR,	OPT_CANCEL,
-	OPT_CREATE,	OPT_DELETE,	OPT_EVAL,	OPT_EXISTS,
-	OPT_EXPOSE,	OPT_HIDE,	OPT_HIDDEN,	OPT_ISSAFE,
+	OPT_CREATE,	OPT_DEBUG,	OPT_DELETE,
+	OPT_EVAL,	OPT_EXISTS,	OPT_EXPOSE,
+	OPT_HIDE,	OPT_HIDDEN,	OPT_ISSAFE,
 	OPT_INVOKEHID,	OPT_LIMIT,	OPT_MARKTRUSTED,OPT_RECLIMIT,
 	OPT_SLAVES,	OPT_SHARE,	OPT_TARGET,	OPT_TRANSFER
     };
@@ -784,6 +789,23 @@ Tcl_InterpObjCmd(
 	Tcl_SetObjResult(interp, slavePtr);
 	return TCL_OK;
     }
+    case OPT_DEBUG: {
+	/* TIP #378 */
+	Tcl_Interp *slaveInterp;
+
+	/*
+	 * Currently only -frame supported, otherwise ?-option ?value??
+	 */
+	if (objc < 3 || objc > 5) {
+	    Tcl_WrongNumArgs(interp, 2, objv, "path ?-frame ?bool??");
+	    return TCL_ERROR;
+	}
+	slaveInterp = GetInterp(interp, objv[2]);
+	if (slaveInterp == NULL) {
+	    return TCL_ERROR;
+	}
+	return SlaveDebugCmd(interp, slaveInterp, objc - 3, objv + 3);
+    }
     case OPT_DELETE: {
 	int i;
 	InterpInfo *iiPtr;
@@ -2376,14 +2398,16 @@ SlaveObjCmd(
     Tcl_Interp *slaveInterp = clientData;
     int index;
     static const char *const options[] = {
-	"alias",	"aliases",	"bgerror",	"eval",
-	"expose",	"hide",		"hidden",	"issafe",
-	"invokehidden",	"limit",	"marktrusted",	"recursionlimit", NULL
+	"alias",	"aliases",	"bgerror",	"debug",
+	"eval",		"expose",	"hide",		"hidden",
+	"issafe",	"invokehidden",	"limit",	"marktrusted",
+	"recursionlimit", NULL
     };
     enum options {
-	OPT_ALIAS,	OPT_ALIASES,	OPT_BGERROR,	OPT_EVAL,
-	OPT_EXPOSE,	OPT_HIDE,	OPT_HIDDEN,	OPT_ISSAFE,
-	OPT_INVOKEHIDDEN, OPT_LIMIT,	OPT_MARKTRUSTED, OPT_RECLIMIT
+	OPT_ALIAS,	OPT_ALIASES,	OPT_BGERROR,	OPT_DEBUG,
+	OPT_EVAL,	OPT_EXPOSE,	OPT_HIDE,	OPT_HIDDEN,
+	OPT_ISSAFE,	OPT_INVOKEHIDDEN, OPT_LIMIT,	OPT_MARKTRUSTED,
+	OPT_RECLIMIT
     };
 
     if (slaveInterp == NULL) {
@@ -2428,6 +2452,16 @@ SlaveObjCmd(
 	    return TCL_ERROR;
 	}
 	return SlaveBgerror(interp, slaveInterp, objc - 2, objv + 2);
+    case OPT_DEBUG:
+	/*
+	 * TIP #378
+	 * Currently only -frame supported, otherwise ?-option ?value? ...?
+	 */
+	if (objc > 4) {
+	    Tcl_WrongNumArgs(interp, 2, objv, "?-frame ?bool??");
+	    return TCL_ERROR;
+	}
+	return SlaveDebugCmd(interp, slaveInterp, objc - 2, objv + 2);
     case OPT_EVAL:
 	if (objc < 3) {
 	    Tcl_WrongNumArgs(interp, 2, objv, "arg ?arg ...?");
@@ -2591,6 +2625,75 @@ SlaveObjCmdDeleteProc(
 /*
  *----------------------------------------------------------------------
  *
+ * SlaveDebugCmd -- TIP #378
+ *
+ *	Helper function to handle 'debug' command in a slave interpreter.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	May modify INTERP_DEBUG_FRAME flag in the slave.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static int
+SlaveDebugCmd(
+    Tcl_Interp *interp,		/* Interp for error return. */
+    Tcl_Interp *slaveInterp,	/* The slave interpreter in which command
+				 * will be evaluated. */
+    int objc,			/* Number of arguments. */
+    Tcl_Obj *const objv[])	/* Argument objects. */
+{
+    static const char *const debugTypes[] = {
+	"-frame", NULL
+    };
+    enum DebugTypes {
+	DEBUG_TYPE_FRAME
+    };
+    int debugType;
+    Interp *iPtr;
+    Tcl_Obj *resultPtr;
+
+    iPtr = (Interp *) slaveInterp;
+    if (objc == 0) {
+	resultPtr = Tcl_NewObj();
+	Tcl_ListObjAppendElement(NULL, resultPtr,
+		Tcl_NewStringObj("-frame", -1));
+	Tcl_ListObjAppendElement(NULL, resultPtr,
+		Tcl_NewBooleanObj(iPtr->flags & INTERP_DEBUG_FRAME));
+	Tcl_SetObjResult(interp, resultPtr);
+    } else {
+	if (Tcl_GetIndexFromObj(interp, objv[0], debugTypes,
+			"debug option", 0, &debugType) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+	if (debugType == DEBUG_TYPE_FRAME) {
+	    if (objc == 2) { /* set */
+		if (Tcl_GetBooleanFromObj(interp, objv[1], &debugType)
+			!= TCL_OK) {
+		    return TCL_ERROR;
+		}
+		/*
+		 * Quietly ignore attempts to disable interp debugging.
+		 * This is a one-way switch as frame debug info is maintained
+		 * in a stack that must be consistent once turned on.
+		 */
+		if (debugType) {
+		    iPtr->flags |= INTERP_DEBUG_FRAME;
+		}
+	    }
+	    Tcl_SetObjResult(interp,
+		    Tcl_NewBooleanObj(iPtr->flags & INTERP_DEBUG_FRAME));
+	}
+    }
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
  * SlaveEval --
  *
  *	Helper function to evaluate a command in a slave interpreter.