The value TCL_LOCATION_EVAL_LIST in the type field of a CmdFrame appears to

exist only for the sake of taking great pains to make sure that pure list
values remain pure list values.

The value of pure list values is no longer what it once was. For a long long
time now, any canonical list values have been equally good.

7 files changed, 59 insertions, 97 deletions

diff --git a/generic/tclBasic.c b/generic/tclBasic.c
index 82affb0..baa2f2c 100644
--- a/generic/tclBasic.c
+++ b/generic/tclBasic.c
@@ -128,7 +128,7 @@ static Tcl_ObjCmdProc	ExprSrandFunc;
 static Tcl_ObjCmdProc	ExprUnaryFunc;
 static Tcl_ObjCmdProc	ExprWideFunc;
 static Tcl_Obj *	GetCommandSource(Interp *iPtr, int objc,
-			    Tcl_Obj *const objv[], int lookup);
+			    Tcl_Obj *const objv[]);
 static void		MathFuncWrongNumArgs(Tcl_Interp *interp, int expected,
 			    int actual, Tcl_Obj *const *objv);
 static Tcl_NRPostProc	NRCoroutineCallerCallback;
@@ -3374,8 +3374,7 @@ static Tcl_Obj *
 GetCommandSource(
     Interp *iPtr,
     int objc,
-    Tcl_Obj *const objv[],
-    int lookup)
+    Tcl_Obj *const objv[])
 {
     Tcl_Obj *objPtr, *obj2Ptr;
     CmdFrame *cfPtr = iPtr->cmdFramePtr;
@@ -3383,20 +3382,17 @@ GetCommandSource(
     int numChars;
 
     objPtr = Tcl_NewListObj(objc, objv);
-    if (lookup && cfPtr && (cfPtr->numLevels == iPtr->numLevels-1)) {
+    if (cfPtr && (cfPtr->numLevels == iPtr->numLevels-1)) {
 	switch (cfPtr->type) {
 	case TCL_LOCATION_EVAL:
 	case TCL_LOCATION_SOURCE:
-	    command = cfPtr->cmd.str.cmd;
-	    numChars = cfPtr->cmd.str.len;
+	    command = cfPtr->cmd;
+	    numChars = cfPtr->len;
 	    break;
 	case TCL_LOCATION_BC:
 	case TCL_LOCATION_PREBC:
 	    command = TclGetSrcInfoForCmd(iPtr, &numChars);
 	    break;
-	case TCL_LOCATION_EVAL_LIST:
-	    /* Got it already */
-	    break;
 	}
 	if (command) {
 	    obj2Ptr = Tcl_NewStringObj(command, numChars);
@@ -4692,7 +4688,7 @@ TEOV_RunEnterTraces(
     int length;
     Tcl_Obj *commandPtr;
 
-    commandPtr = GetCommandSource(iPtr, objc, objv, 1);
+    commandPtr = GetCommandSource(iPtr, objc, objv);
     command = Tcl_GetStringFromObj(commandPtr, &length);
 
     /*
@@ -5250,12 +5246,12 @@ TclEvalEx(
 	     * have been executed.
 	     */
 
-	    eeFramePtr->cmd.str.cmd = parsePtr->commandStart;
-	    eeFramePtr->cmd.str.len = parsePtr->commandSize;
+	    eeFramePtr->cmd = parsePtr->commandStart;
+	    eeFramePtr->len = parsePtr->commandSize;
 
 	    if (parsePtr->term ==
 		    parsePtr->commandStart + parsePtr->commandSize - 1) {
-		eeFramePtr->cmd.str.len--;
+		eeFramePtr->len--;
 	    }
 
 	    eeFramePtr->nline = objectsUsed;
@@ -5974,13 +5970,12 @@ TclNREvalObjEx(
      */
 
     if (TclListObjIsCanonical(objPtr)) {
-	Tcl_Obj *listPtr = objPtr;
 	CmdFrame *eoFramePtr = NULL;
 	int objc;
-	Tcl_Obj **objv;
+	Tcl_Obj *listPtr, **objv;
 
 	/*
-	 * Pure List Optimization (no string representation). In this case, we
+	 * Canonical List Optimization:  In this case, we
 	 * can safely use Tcl_EvalObjv instead and get an appreciable
 	 * improvement in execution speed. This is because it allows us to
 	 * avoid a setFromAny step that would just pack everything into a
@@ -5988,11 +5983,6 @@ TclNREvalObjEx(
 	 *
 	 * This also preserves any associations between list elements and
 	 * location information for such elements.
-	 *
-	 * This restriction has been relaxed a bit by storing in lists whether
-	 * they are "canonical" or not (a canonical list being one that is
-	 * either pure or that has its string rep derived by
-	 * UpdateStringOfList from the internal rep).
 	 */
 
 	/*
@@ -6001,6 +5991,7 @@ TclNREvalObjEx(
 	 * we always make a copy. The callback takes care od the refCounts for
 	 * both listPtr and objPtr.
 	 *
+	 * TODO: Create a test to demo this need, or eliminate it.
 	 * FIXME OPT: preserve just the internal rep?
 	 */
 
@@ -6030,14 +6021,14 @@ TclNREvalObjEx(
 	    eoFramePtr->nline = 0;
 	    eoFramePtr->line = NULL;
 
-	    eoFramePtr->type = TCL_LOCATION_EVAL_LIST;
+	    eoFramePtr->type = TCL_LOCATION_EVAL;
 	    eoFramePtr->level = (iPtr->cmdFramePtr == NULL?
 		    1 : iPtr->cmdFramePtr->level + 1);
 	    eoFramePtr->numLevels = iPtr->numLevels;
 	    eoFramePtr->framePtr = iPtr->framePtr;
 	    eoFramePtr->nextPtr = iPtr->cmdFramePtr;
 
-	    eoFramePtr->cmd.listPtr = listPtr;
+	    eoFramePtr->cmd = Tcl_GetStringFromObj(listPtr, &(eoFramePtr->len));
 	    eoFramePtr->data.eval.path = NULL;
 
 	    iPtr->cmdFramePtr = eoFramePtr;
diff --git a/generic/tclCmdIL.c b/generic/tclCmdIL.c
index 0e33392..180d814 100644
--- a/generic/tclCmdIL.c
+++ b/generic/tclCmdIL.c
@@ -1302,28 +1302,12 @@ TclInfoFrame(
 	 */
 
 	ADD_PAIR("type", Tcl_NewStringObj(typeString[framePtr->type], -1));
-	ADD_PAIR("line", Tcl_NewIntObj(framePtr->line[0]));
-	ADD_PAIR("cmd", Tcl_NewStringObj(framePtr->cmd.str.cmd,
-		framePtr->cmd.str.len));
-	break;
-
-    case TCL_LOCATION_EVAL_LIST:
-	/*
-	 * List optimized evaluation. Type, line, cmd, the latter through
-	 * listPtr, possibly a frame.
-	 */
-
-	ADD_PAIR("type", Tcl_NewStringObj(typeString[framePtr->type], -1));
-	ADD_PAIR("line", Tcl_NewIntObj(1));
-
-	/*
-	 * We put a duplicate of the command list obj into the result to
-	 * ensure that the 'pure List'-property of the command itself is not
-	 * destroyed. Otherwise the query here would disable the list
-	 * optimization path in Tcl_EvalObjEx.
-	 */
-
-	ADD_PAIR("cmd", Tcl_DuplicateObj(framePtr->cmd.listPtr));
+	if (framePtr->line) {
+	    ADD_PAIR("line", Tcl_NewIntObj(framePtr->line[0]));
+	} else {
+	    ADD_PAIR("line", Tcl_NewIntObj(1));
+	}
+	ADD_PAIR("cmd", Tcl_NewStringObj(framePtr->cmd, framePtr->len));
 	break;
 
     case TCL_LOCATION_PREBC:
@@ -1371,8 +1355,7 @@ TclInfoFrame(
 	    Tcl_DecrRefCount(fPtr->data.eval.path);
 	}
 
-	ADD_PAIR("cmd",
-		Tcl_NewStringObj(fPtr->cmd.str.cmd, fPtr->cmd.str.len));
+	ADD_PAIR("cmd", Tcl_NewStringObj(fPtr->cmd, fPtr->len));
 	TclStackFree(interp, fPtr);
 	break;
     }
@@ -1391,8 +1374,7 @@ TclInfoFrame(
 	 * the result list object.
 	 */
 
-	ADD_PAIR("cmd", Tcl_NewStringObj(framePtr->cmd.str.cmd,
-		framePtr->cmd.str.len));
+	ADD_PAIR("cmd", Tcl_NewStringObj(framePtr->cmd, framePtr->len));
 	break;
 
     case TCL_LOCATION_PROC:
diff --git a/generic/tclCompile.c b/generic/tclCompile.c
index 772ce22..618b6fa 100644
--- a/generic/tclCompile.c
+++ b/generic/tclCompile.c
@@ -1375,7 +1375,7 @@ TclInitCompileEnv(
     envPtr->extCmdMapPtr->nuloc = 0;
     envPtr->extCmdMapPtr->path = NULL;
 
-    if ((invoker == NULL) || (invoker->type == TCL_LOCATION_EVAL_LIST)) {
+    if (invoker == NULL) {
 	/*
 	 * Initialize the compiler for relative counting in case of a
 	 * dynamic context.
diff --git a/generic/tclExecute.c b/generic/tclExecute.c
index f8ed667..11e9920 100644
--- a/generic/tclExecute.c
+++ b/generic/tclExecute.c
@@ -2006,8 +2006,8 @@ TclNRExecuteByteCode(
     bcFramePtr->litarg = NULL;
     bcFramePtr->data.tebc.codePtr = codePtr;
     bcFramePtr->data.tebc.pc = NULL;
-    bcFramePtr->cmd.str.cmd = NULL;
-    bcFramePtr->cmd.str.len = 0;
+    bcFramePtr->cmd = NULL;
+    bcFramePtr->len = 0;
 
 #ifdef TCL_COMPILE_STATS
     iPtr->stats.numExecutions++;
@@ -8774,13 +8774,13 @@ TclGetSrcInfoForPc(
 {
     ByteCode *codePtr = (ByteCode *) cfPtr->data.tebc.codePtr;
 
-    if (cfPtr->cmd.str.cmd == NULL) {
-	cfPtr->cmd.str.cmd = GetSrcInfoForPc(
+    if (cfPtr->cmd == NULL) {
+	cfPtr->cmd = GetSrcInfoForPc(
 		(unsigned char *) cfPtr->data.tebc.pc, codePtr,
-		&cfPtr->cmd.str.len, NULL, NULL);
+		&cfPtr->len, NULL, NULL);
     }
 
-    if (cfPtr->cmd.str.cmd != NULL) {
+    if (cfPtr->cmd != NULL) {
 	/*
 	 * We now have the command. We can get the srcOffset back and from
 	 * there find the list of word locations for this command.
@@ -8797,7 +8797,7 @@ TclGetSrcInfoForPc(
 	    return;
 	}
 
-	srcOffset = cfPtr->cmd.str.cmd - codePtr->source;
+	srcOffset = cfPtr->cmd - codePtr->source;
 	eclPtr = Tcl_GetHashValue(hePtr);
 
 	for (i=0; i < eclPtr->nuloc; i++) {
diff --git a/generic/tclInt.h b/generic/tclInt.h
index da09366..cd4ab7d 100644
--- a/generic/tclInt.h
+++ b/generic/tclInt.h
@@ -1175,29 +1175,27 @@ typedef struct CmdFrame {
      *
      * EXECUTION CONTEXTS and usage of CmdFrame
      *
-     * Field	  TEBC		  EvalEx	  EvalObjEx
-     * =======	  ====		  ======	  =========
-     * level	  yes		  yes		  yes
-     * type	  BC/PREBC	  SRC/EVAL	  EVAL_LIST
-     * line0	  yes		  yes		  yes
-     * framePtr	  yes		  yes		  yes
-     * =======	  ====		  ======	  =========
+     * Field	  TEBC		  EvalEx
+     * =======	  ====		  ======
+     * level	  yes		  yes	
+     * type	  BC/PREBC	  SRC/EVAL
+     * line0	  yes		  yes	
+     * framePtr	  yes		  yes	
+     * =======	  ====		  ======
      *
-     * =======	  ====		  ======	  ========= union data
-     * line1	  -		  yes		  -
-     * line3	  -		  yes		  -
-     * path	  -		  yes		  -
-     * -------	  ----		  ------	  ---------
-     * codePtr	  yes		  -		  -
-     * pc	  yes		  -		  -
-     * =======	  ====		  ======	  =========
+     * =======	  ====		  ========= union data
+     * line1	  -		  yes	
+     * line3	  -		  yes	
+     * path	  -		  yes	
+     * -------	  ----		  ------
+     * codePtr	  yes		  -	
+     * pc	  yes		  -	
+     * =======	  ====		  ======
      *
-     * =======	  ====		  ======	  ========= | union cmd
-     * listPtr	  -		  -		  yes	    |
-     * -------	  ----		  ------	  --------- |
-     * cmd	  yes		  yes		  -	    |
-     * cmdlen	  yes		  yes		  -	    |
-     * -------	  ----		  ------	  --------- |
+     * =======	  ====		  ========= union cmd
+     * str.cmd	  yes		  yes	
+     * str.len	  yes		  yes	
+     * -------	  ----		  ------	
      */
 
     union {
@@ -1210,13 +1208,8 @@ typedef struct CmdFrame {
 	    const char *pc;	/* ... and instruction pointer. */
 	} tebc;
     } data;
-    union {
-	struct {
-	    const char *cmd;	/* The executed command, if possible... */
-	    int len;		/* ... and its length. */
-	} str;
-	Tcl_Obj *listPtr;	/* Tcl_EvalObjEx, cmd list. */
-    } cmd;
+    const char *cmd;		/* The executed command, if possible... */
+    int len;			/* ... and its length. */
     int numLevels;		/* Value of interp's numLevels when the frame
 				 * was pushed. */
     const struct CFWordBC *litarg;
@@ -1282,8 +1275,6 @@ typedef struct ContLineLoc {
  * location data referenced via the 'baseLocPtr'.
  *
  * TCL_LOCATION_EVAL	  : Frame is for a script evaluated by EvalEx.
- * TCL_LOCATION_EVAL_LIST : Frame is for a script evaluated by the list
- *			    optimization path of EvalObjEx.
  * TCL_LOCATION_BC	  : Frame is for bytecode.
  * TCL_LOCATION_PREBC	  : Frame is for precompiled bytecode.
  * TCL_LOCATION_SOURCE	  : Frame is for a script evaluated by EvalEx, from a
@@ -1295,8 +1286,6 @@ typedef struct ContLineLoc {
  */
 
 #define TCL_LOCATION_EVAL	(0) /* Location in a dynamic eval script. */
-#define TCL_LOCATION_EVAL_LIST	(1) /* Location in a dynamic eval script,
-				     * list-path. */
 #define TCL_LOCATION_BC		(2) /* Location in byte code. */
 #define TCL_LOCATION_PREBC	(3) /* Location in precompiled byte code, no
 				     * location. */
diff --git a/generic/tclOOMethod.c b/generic/tclOOMethod.c
index 98b4078..b91fdfd 100644
--- a/generic/tclOOMethod.c
+++ b/generic/tclOOMethod.c
@@ -513,8 +513,8 @@ TclOOMakeProcInstanceMethod(
 		cfPtr->data.eval.path = context.data.eval.path;
 		Tcl_IncrRefCount(cfPtr->data.eval.path);
 
-		cfPtr->cmd.str.cmd = NULL;
-		cfPtr->cmd.str.len = 0;
+		cfPtr->cmd = NULL;
+		cfPtr->len = 0;
 
 		hPtr = Tcl_CreateHashEntry(iPtr->linePBodyPtr,
 			(char *) procPtr, &isNew);
@@ -626,8 +626,8 @@ TclOOMakeProcMethod(
 		cfPtr->data.eval.path = context.data.eval.path;
 		Tcl_IncrRefCount(cfPtr->data.eval.path);
 
-		cfPtr->cmd.str.cmd = NULL;
-		cfPtr->cmd.str.len = 0;
+		cfPtr->cmd = NULL;
+		cfPtr->len = 0;
 
 		hPtr = Tcl_CreateHashEntry(iPtr->linePBodyPtr,
 			(char *) procPtr, &isNew);
diff --git a/generic/tclProc.c b/generic/tclProc.c
index 18985a1..1314719 100644
--- a/generic/tclProc.c
+++ b/generic/tclProc.c
@@ -271,8 +271,8 @@ Tcl_ProcObjCmd(
 		cfPtr->data.eval.path = contextPtr->data.eval.path;
 		Tcl_IncrRefCount(cfPtr->data.eval.path);
 
-		cfPtr->cmd.str.cmd = NULL;
-		cfPtr->cmd.str.len = 0;
+		cfPtr->cmd = NULL;
+		cfPtr->len = 0;
 
 		hePtr = Tcl_CreateHashEntry(iPtr->linePBodyPtr,
 			procPtr, &isNew);
@@ -2595,8 +2595,8 @@ SetLambdaFromAny(
 		cfPtr->data.eval.path = contextPtr->data.eval.path;
 		Tcl_IncrRefCount(cfPtr->data.eval.path);
 
-		cfPtr->cmd.str.cmd = NULL;
-		cfPtr->cmd.str.len = 0;
+		cfPtr->cmd = NULL;
+		cfPtr->len = 0;
 	    }
 
 	    /*