merge trunk

17 files changed, 172 insertions, 83 deletions

diff --git a/doc/Tcl.n b/doc/Tcl.n
index 8b17f93..c7fa9f6 100644
--- a/doc/Tcl.n
+++ b/doc/Tcl.n
@@ -108,8 +108,8 @@ Variable substitution may take any of the following forms:
 \fIName\fR is the name of a scalar variable;  the name is a sequence
 of one or more characters that are a letter, digit, underscore,
 or namespace separators (two or more colons).
-Letters and digits are \fIonly\fR the standard ASCII ones (\fB0\fR\-\fB9\fR,
-\fBA\fR\-\fBZ\fR and \fBa\fR\-\fBz\fR).
+Letters and digits are \fIonly\fR the standard ASCII ones (\fB0\fR\(en\fB9\fR,
+\fBA\fR\(en\fBZ\fR and \fBa\fR\(en\fBz\fR).
 .TP 15
 \fB$\fIname\fB(\fIindex\fB)\fR
 .
@@ -117,8 +117,8 @@ Letters and digits are \fIonly\fR the standard ASCII ones (\fB0\fR\-\fB9\fR,
 the name of an element within that array.
 \fIName\fR must contain only letters, digits, underscores, and
 namespace separators, and may be an empty string.
-Letters and digits are \fIonly\fR the standard ASCII ones (\fB0\fR\-\fB9\fR,
-\fBA\fR\-\fBZ\fR and \fBa\fR\-\fBz\fR).
+Letters and digits are \fIonly\fR the standard ASCII ones (\fB0\fR\(en\fB9\fR,
+\fBA\fR\(en\fBZ\fR and \fBa\fR\(en\fBz\fR).
 Command substitutions, variable substitutions, and backslash
 substitutions are performed on the characters of \fIindex\fR.
 .TP 15
@@ -158,25 +158,25 @@ handled specially, along with the value that replaces each sequence.
 .RS
 .TP 7
 \e\fBa\fR
-Audible alert (bell) (0x7).
+Audible alert (bell) (Unicode U+000007).
 .TP 7
 \e\fBb\fR
-Backspace (0x8).
+Backspace (Unicode U+000008).
 .TP 7
 \e\fBf\fR
-Form feed (0xc).
+Form feed (Unicode U+00000C).
 .TP 7
 \e\fBn\fR
-Newline (0xa).
+Newline (Unicode U+00000A).
 .TP 7
 \e\fBr\fR
-Carriage-return (0xd).
+Carriage-return (Unicode U+00000D).
 .TP 7
 \e\fBt\fR
-Tab (0x9).
+Tab (Unicode U+000009).
 .TP 7
 \e\fBv\fR
-Vertical tab (0xb).
+Vertical tab (Unicode U+00000B).
 .TP 7
 \e\fB<newline>\fIwhiteSpace\fR
 .
@@ -194,8 +194,9 @@ Backslash
 \e\fIooo\fR 
 .
 The digits \fIooo\fR (one, two, or three of them) give a eight-bit octal 
-value for the Unicode character that will be inserted, in the range \fI000\fR
-- \fI377\fR.  The parser will stop just before this range overflows, or when
+value for the Unicode character that will be inserted, in the range
+\fI000\fR\(en\fI377\fR (i.e., the range U+000000\(enU+0000FF).
+The parser will stop just before this range overflows, or when
 the maximum of three digits is reached.  The upper bits of the Unicode
 character will be 0.
 .TP 7
@@ -203,23 +204,27 @@ character will be 0.
 .
 The hexadecimal digits \fIhh\fR (one or two of them) give an eight-bit
 hexadecimal value for the Unicode character that will be inserted.  The upper
-bits of the Unicode character will be 0.
+bits of the Unicode character will be 0 (i.e., the character will be in the
+range U+000000\(enU+0000FF).
 .TP 7
 \e\fBu\fIhhhh\fR 
 .
 The hexadecimal digits \fIhhhh\fR (one, two, three, or four of them) give a
 sixteen-bit hexadecimal value for the Unicode character that will be
-inserted.  The upper bits of the Unicode character will be 0.
+inserted.  The upper bits of the Unicode character will be 0 (i.e., the
+character will be in the range U+000000\(enU+00FFFF).
 .TP 7
 \e\fBU\fIhhhhhhhh\fR 
 .
 The hexadecimal digits \fIhhhhhhhh\fR (one up to eight of them) give a
 twenty-one-bit hexadecimal value for the Unicode character that will be
-inserted, in the range U+0000..U+10FFFF.  The parser will stop just
+inserted, in the range U+000000\(enU+10FFFF.  The parser will stop just
 before this range overflows, or when the maximum of eight digits
 is reached.  The upper bits of the Unicode character will be 0.
+.RS
 .PP
-The range U+010000..U+10FFFD is reserved for the future.
+The range U+010000\(enU+10FFFD is reserved for the future.
+.RE
 .PP
 Backslash substitution is not performed on words enclosed in braces,
 except for backslash-newline as described above.
diff --git a/generic/tclBasic.c b/generic/tclBasic.c
index 8d77cc5..7c02706 100644
--- a/generic/tclBasic.c
+++ b/generic/tclBasic.c
@@ -526,6 +526,9 @@ Tcl_CreateInterp(void)
     iPtr->hiddenCmdTablePtr = NULL;
     iPtr->interpInfo = NULL;
 
+    TCL_CT_ASSERT(sizeof(iPtr->extra) <= sizeof(Tcl_HashTable));
+    iPtr->extra.optimizer = TclOptimizeBytecode;
+
     iPtr->numLevels = 0;
     iPtr->maxNestingDepth = MAX_NESTING_DEPTH;
     iPtr->framePtr = NULL;	/* Initialise as soon as :: is available */
diff --git a/generic/tclCmdIL.c b/generic/tclCmdIL.c
index fa4ead4..41c1eb6 100644
--- a/generic/tclCmdIL.c
+++ b/generic/tclCmdIL.c
@@ -1147,41 +1147,38 @@ InfoFrameCmd(
     Tcl_Obj *const objv[])	/* Argument objects. */
 {
     Interp *iPtr = (Interp *) interp;
-    int level, topLevel, code = TCL_OK;
-    CmdFrame *runPtr, *framePtr;
+    int level, code = TCL_OK;
+    CmdFrame *framePtr, **cmdFramePtrPtr = &iPtr->cmdFramePtr;
     CoroutineData *corPtr = iPtr->execEnvPtr->corPtr;
+    int topLevel = 0;
 
     if (objc > 2) {
 	Tcl_WrongNumArgs(interp, 1, objv, "?number?");
 	return TCL_ERROR;
     }
 
-    topLevel = ((iPtr->cmdFramePtr == NULL)
-	    ? 0
-	    : iPtr->cmdFramePtr->level);
-
-    if (corPtr) {
-	/*
-	 * A coroutine: must fix the level computations AND the cmdFrame chain,
-	 * which is interrupted at the base.
-	 */
-
-	CmdFrame *lastPtr = NULL;
-
-	runPtr = iPtr->cmdFramePtr;
+    while (corPtr) {
+	while (*cmdFramePtrPtr) {
+	    topLevel++;
+	    cmdFramePtrPtr = &((*cmdFramePtrPtr)->nextPtr);
+	}
+	if (corPtr->caller.cmdFramePtr) {
+	    *cmdFramePtrPtr = corPtr->caller.cmdFramePtr;
+	}
+	corPtr = corPtr->callerEEPtr->corPtr;
+    }
+    topLevel += (*cmdFramePtrPtr)->level;
 
-	/* TODO - deal with overflow */
-	topLevel += corPtr->caller.cmdFramePtr->level;
-	while (runPtr) {
-	    runPtr->level += corPtr->caller.cmdFramePtr->level;
-	    lastPtr = runPtr;
-	    runPtr = runPtr->nextPtr;
+    if (topLevel != iPtr->cmdFramePtr->level) {
+	framePtr = iPtr->cmdFramePtr;
+	while (framePtr) {
+	    framePtr->level = topLevel--;
+	    framePtr = framePtr->nextPtr;
 	}
-	if (lastPtr) {
-	    lastPtr->nextPtr = corPtr->caller.cmdFramePtr;
-	} else {
-	    iPtr->cmdFramePtr = corPtr->caller.cmdFramePtr;
+	if (topLevel) {
+	    Tcl_Panic("Broken frame level calculation");
 	}
+	topLevel = iPtr->cmdFramePtr->level;
     }
 
     if (objc == 1) {
@@ -1231,20 +1228,27 @@ InfoFrameCmd(
     Tcl_SetObjResult(interp, TclInfoFrame(interp, framePtr));
 
   done:
-    if (corPtr) {
+    cmdFramePtrPtr = &iPtr->cmdFramePtr;
+    corPtr = iPtr->execEnvPtr->corPtr;
+    while (corPtr) {
+	CmdFrame *endPtr = corPtr->caller.cmdFramePtr;
+
+	if (endPtr) {
+	    if (*cmdFramePtrPtr == endPtr) {
+		*cmdFramePtrPtr = NULL;
+	    } else {
+		CmdFrame *runPtr = *cmdFramePtrPtr;
 
-	if (iPtr->cmdFramePtr == corPtr->caller.cmdFramePtr) {
-	    iPtr->cmdFramePtr = NULL;
-	} else {
-	    runPtr = iPtr->cmdFramePtr;
-	    while (runPtr->nextPtr != corPtr->caller.cmdFramePtr) {
-	    	runPtr->level -= corPtr->caller.cmdFramePtr->level;
-		runPtr = runPtr->nextPtr;
+		while (runPtr->nextPtr != endPtr) {
+		    runPtr->level -= endPtr->level;
+		    runPtr = runPtr->nextPtr;
+		}
+		runPtr->level = 1;
+		runPtr->nextPtr = NULL;
 	    }
-	    runPtr->level = 1;
-	    runPtr->nextPtr = NULL;
+	    cmdFramePtrPtr = &corPtr->caller.cmdFramePtr;
 	}
-
+	corPtr = corPtr->callerEEPtr->corPtr;
     }
     return code;
 }
diff --git a/generic/tclCompCmds.c b/generic/tclCompCmds.c
index d027f1c..51ac9ed 100644
--- a/generic/tclCompCmds.c
+++ b/generic/tclCompCmds.c
@@ -496,17 +496,14 @@ TclCompileBreakCmd(
 
 	TclCleanupStackForBreakContinue(envPtr, auxPtr);
 	TclAddLoopBreakFixup(envPtr, auxPtr);
-	TclAdjustStackDepth(1, envPtr);
     } else {
 	/*
 	 * Emit a real break.
 	 */
 
-	PushStringLiteral(envPtr, "");
-	TclEmitOpcode(INST_DUP, envPtr);
-	TclEmitInstInt4(INST_RETURN_IMM, TCL_BREAK, envPtr);
-	TclEmitInt4(0, envPtr);
+	TclEmitOpcode(INST_BREAK, envPtr);
     }
+    TclAdjustStackDepth(1, envPtr);
 
     return TCL_OK;
 }
@@ -540,9 +537,10 @@ TclCompileCatchCmd(
 {
     JumpFixup jumpFixup;
     Tcl_Token *cmdTokenPtr, *resultNameTokenPtr, *optsNameTokenPtr;
-    int resultIndex, optsIndex, range;
+    int resultIndex, optsIndex, range, dropScript = 0;
     DefineLineInformation;	/* TIP #280 */
-
+    int depth = TclGetStackDepth(envPtr);
+    
     /*
      * If syntax does not match what we expect for [catch], do not compile.
      * Let runtime checks determine if syntax has changed.
@@ -615,16 +613,19 @@ TclCompileCatchCmd(
 	TclEmitOpcode(		INST_DUP,			envPtr);
 	TclEmitInvoke(envPtr,	INST_EVAL_STK);
 	/* drop the script */
+	dropScript = 1;
 	TclEmitInstInt4(	INST_REVERSE, 2,		envPtr);
 	TclEmitOpcode(		INST_POP,			envPtr);
     }
     ExceptionRangeEnds(envPtr, range);
 
+    
     /*
      * Emit the "no errors" epilogue: push "0" (TCL_OK) as the catch result,
      * and jump around the "error case" code.
      */
 
+    TclCheckStackDepth(depth+1, envPtr);
     PushStringLiteral(envPtr, "0");
     TclEmitForwardJump(envPtr, TCL_UNCONDITIONAL_JUMP, &jumpFixup);
 
@@ -633,8 +634,14 @@ TclCompileCatchCmd(
      * return code.
      */
 
-    TclAdjustStackDepth(-2, envPtr);
     ExceptionRangeTarget(envPtr, range, catchOffset);
+    TclSetStackDepth(depth + dropScript, envPtr);
+    
+    if (dropScript) {
+	TclEmitOpcode(		INST_POP,			envPtr);
+    }
+
+
     /* Stack at this point is empty */
     TclEmitOpcode(		INST_PUSH_RESULT,		envPtr);
     TclEmitOpcode(		INST_PUSH_RETURN_CODE,		envPtr);
@@ -683,6 +690,7 @@ TclCompileCatchCmd(
     }
     TclEmitOpcode(	INST_POP,			envPtr);
 
+    TclCheckStackDepth(depth+1, envPtr);
     return TCL_OK;
 }
 
@@ -824,17 +832,14 @@ TclCompileContinueCmd(
 
 	TclCleanupStackForBreakContinue(envPtr, auxPtr);
 	TclAddLoopContinueFixup(envPtr, auxPtr);
-	TclAdjustStackDepth(1, envPtr);
     } else {
 	/*
 	 * Emit a real continue.
 	 */
 
-	PushStringLiteral(envPtr, "");
-	TclEmitOpcode(INST_DUP, envPtr);
-	TclEmitInstInt4(INST_RETURN_IMM, TCL_CONTINUE, envPtr);
-	TclEmitInt4(0, envPtr);
+	TclEmitOpcode(INST_CONTINUE, envPtr);
     }
+    TclAdjustStackDepth(1, envPtr);
 
     return TCL_OK;
 }
@@ -2370,6 +2375,7 @@ TclCompileForCmd(
 
     SetLineInformation(2);
     TclCompileExprWords(interp, testTokenPtr, 1, envPtr);
+    TclClearNumConversion(envPtr);
 
     jumpDist = CurrentOffset(envPtr) - bodyCodeOffset;
     if (jumpDist > 127) {
diff --git a/generic/tclCompCmdsGR.c b/generic/tclCompCmdsGR.c
index 50fb8e9..fc54620 100644
--- a/generic/tclCompCmdsGR.c
+++ b/generic/tclCompCmdsGR.c
@@ -281,6 +281,7 @@ TclCompileIfCmd(
 		SetLineInformation(wordIdx);
 		Tcl_ResetResult(interp);
 		TclCompileExprWords(interp, testTokenPtr, 1, envPtr);
+		TclClearNumConversion(envPtr);
 		if (jumpFalseFixupArray.next >= jumpFalseFixupArray.end) {
 		    TclExpandJumpFixupArray(&jumpFalseFixupArray);
 		}
@@ -530,6 +531,7 @@ TclCompileIncrCmd(
 	} else {
 	    SetLineInformation(2);
 	    CompileTokens(envPtr, incrTokenPtr, interp);
+	    TclClearNumConversion(envPtr);
 	}
     } else {			/* No incr amount given so use 1. */
 	haveImmValue = 1;
diff --git a/generic/tclCompCmdsSZ.c b/generic/tclCompCmdsSZ.c
index e7b3ddc..110476e 100644
--- a/generic/tclCompCmdsSZ.c
+++ b/generic/tclCompCmdsSZ.c
@@ -3383,6 +3383,7 @@ TclCompileWhileCmd(
 	}
 	SetLineInformation(1);
 	TclCompileExprWords(interp, testTokenPtr, 1, envPtr);
+	TclClearNumConversion(envPtr);
 
 	jumpDist = CurrentOffset(envPtr) - bodyCodeOffset;
 	if (jumpDist > 127) {
diff --git a/generic/tclCompile.c b/generic/tclCompile.c
index 14d9451..db97c45 100644
--- a/generic/tclCompile.c
+++ b/generic/tclCompile.c
@@ -816,7 +816,9 @@ TclSetByteCodeFromAny(
      * instruction generator boundaries.
      */
 
-    TclOptimizeBytecode(&compEnv);
+    if (iPtr->extra.optimizer) {
+	(iPtr->extra.optimizer)(&compEnv);
+    }
 
     /*
      * Invoke the compilation hook procedure if one exists.
@@ -1771,7 +1773,7 @@ TclCompileInvocation(
     int numWords,
     CompileEnv *envPtr)
 {
-    int wordIdx = 0;
+    int wordIdx = 0, depth = TclGetStackDepth(envPtr);
     DefineLineInformation;
 
     if (cmdObj) {
@@ -1804,6 +1806,7 @@ TclCompileInvocation(
     } else {
 	TclEmitInvoke(envPtr, INST_INVOKE_STK4, wordIdx);
     }
+    TclCheckStackDepth(depth+1, envPtr);
 }
 
 static void
@@ -1816,7 +1819,8 @@ CompileExpanded(
 {
     int wordIdx = 0;
     DefineLineInformation;
-
+    int depth = TclGetStackDepth(envPtr);
+    
     StartExpanding(envPtr);
     if (cmdObj) {
 	CompileCmdLiteral(interp, cmdObj, envPtr);
@@ -1862,6 +1866,7 @@ CompileExpanded(
      */
 
     TclEmitInvoke(envPtr, INST_INVOKE_EXPANDED, wordIdx);
+    TclCheckStackDepth(depth+1, envPtr);
 }
 
 static int 
@@ -1873,6 +1878,7 @@ CompileCmdCompileProc(
 {
     int unwind = 0, incrOffset = -1;
     DefineLineInformation;
+    int depth = TclGetStackDepth(envPtr);
 
     /*
      * Emit of the INST_START_CMD instruction is controlled by the value of
@@ -1920,6 +1926,7 @@ CompileCmdCompileProc(
 		TclStoreInt4AtPtr(envPtr->codeNext - startPtr, startPtr + 1);
 	    }
 	}
+	TclCheckStackDepth(depth+1, envPtr);
 	return TCL_OK;
     }
 
@@ -1962,7 +1969,8 @@ CompileCommandTokens(
     int *clNext = envPtr->clNext;
     int cmdIdx = envPtr->numCommands;
     int startCodeOffset = envPtr->codeNext - envPtr->codeStart;
-
+    int depth = TclGetStackDepth(envPtr);
+    
     assert (parsePtr->numWords > 0);
 
     /* Pre-Compile */
@@ -2053,6 +2061,7 @@ CompileCommandTokens(
     eclPtr->loc[wlineat].line = wlines;
     eclPtr->loc[wlineat].next = NULL;
 
+    TclCheckStackDepth(depth, envPtr);
     return cmdIdx;
 }
 
@@ -2072,6 +2081,7 @@ TclCompileScript(
 				 * Initial value of -1 indicates this routine
 				 * has not yet generated any bytecode. */
     const char *p = script;	/* Where we are in our compile. */
+    int depth = TclGetStackDepth(envPtr);
 
     if (envPtr->iPtr == NULL) {
 	Tcl_Panic("TclCompileScript() called on uninitialized CompileEnv");
@@ -2183,6 +2193,7 @@ TclCompileScript(
 	envPtr->codeNext--;
 	envPtr->currStackDepth++;
     }
+    TclCheckStackDepth(depth+1, envPtr);
 }
 
 /*
@@ -2293,6 +2304,7 @@ TclCompileTokens(
 #define NUM_STATIC_POS 20
     int isLiteral, maxNumCL, numCL;
     int *clPosition = NULL;
+    int depth = TclGetStackDepth(envPtr);
 
     /*
      * For the handling of continuation lines in literals we first check if
@@ -2470,6 +2482,7 @@ TclCompileTokens(
     if (maxNumCL) {
 	ckfree(clPosition);
     }
+    TclCheckStackDepth(depth+1, envPtr);
 }
 
 /*
@@ -3985,7 +3998,8 @@ TclEmitInvoke(
     ExceptionAux *auxBreakPtr, *auxContinuePtr;
     int arg1, arg2, wordCount = 0, expandCount = 0;
     int loopRange = 0, breakRange = 0, continueRange = 0;
-
+    int cleanup, depth = TclGetStackDepth(envPtr);
+    
     /*
      * Parse the arguments.
      */
@@ -3993,30 +4007,31 @@ TclEmitInvoke(
     va_start(argList, opcode);
     switch (opcode) {
     case INST_INVOKE_STK1:
-	wordCount = arg1 = va_arg(argList, int);
+	wordCount = arg1 = cleanup = va_arg(argList, int);
 	arg2 = 0;
 	break;
     case INST_INVOKE_STK4:
-	wordCount = arg1 = va_arg(argList, int);
+	wordCount = arg1 = cleanup = va_arg(argList, int);
 	arg2 = 0;
 	break;
     case INST_INVOKE_REPLACE:
 	arg1 = va_arg(argList, int);
 	arg2 = va_arg(argList, int);
 	wordCount = arg1 + arg2 - 1;
+	cleanup = arg1 + 1;
 	break;
     default:
 	Tcl_Panic("unexpected opcode");
     case INST_EVAL_STK:
-	wordCount = 1;
+	wordCount = cleanup = 1;
 	arg1 = arg2 = 0;
 	break;
     case INST_RETURN_STK:
-	wordCount = 2;
+	wordCount = cleanup = 2;
 	arg1 = arg2 = 0;
 	break;
     case INST_INVOKE_EXPANDED:
-	wordCount = arg1 = va_arg(argList, int);
+	wordCount = arg1 = cleanup = va_arg(argList, int);
 	arg2 = 0;
 	expandCount = 1;
 	break;
@@ -4119,6 +4134,7 @@ TclEmitInvoke(
 	    ExceptionRangeTarget(envPtr, loopRange, breakOffset);
 	    TclCleanupStackForBreakContinue(envPtr, auxBreakPtr);
 	    TclAddLoopBreakFixup(envPtr, auxBreakPtr);
+	    TclAdjustStackDepth(1, envPtr);
 
 	    envPtr->currStackDepth = savedStackDepth;
 	    envPtr->expandCount = savedExpandCount;
@@ -4130,6 +4146,7 @@ TclEmitInvoke(
 	    ExceptionRangeTarget(envPtr, loopRange, continueOffset);
 	    TclCleanupStackForBreakContinue(envPtr, auxContinuePtr);
 	    TclAddLoopContinueFixup(envPtr, auxContinuePtr);
+	    TclAdjustStackDepth(1, envPtr);
 
 	    envPtr->currStackDepth = savedStackDepth;
 	    envPtr->expandCount = savedExpandCount;
@@ -4138,6 +4155,7 @@ TclEmitInvoke(
 	TclFinalizeLoopExceptionRange(envPtr, loopRange);
 	TclFixupForwardJumpToHere(envPtr, &nonTrapFixup, 127);
     }
+    TclCheckStackDepth(depth+1-cleanup, envPtr);
 }
 
 /*
diff --git a/generic/tclCompile.h b/generic/tclCompile.h
index b2a4b52..6226f7f 100644
--- a/generic/tclCompile.h
+++ b/generic/tclCompile.h
@@ -1074,7 +1074,7 @@ MODULE_SCOPE void	TclFinalizeLoopExceptionRange(CompileEnv *envPtr,
 MODULE_SCOPE char *	TclLiteralStats(LiteralTable *tablePtr);
 MODULE_SCOPE int	TclLog2(int value);
 #endif
-MODULE_SCOPE void	TclOptimizeBytecode(CompileEnv *envPtr);
+MODULE_SCOPE void	TclOptimizeBytecode(void *envPtr);
 #ifdef TCL_COMPILE_DEBUG
 MODULE_SCOPE void	TclPrintByteCodeObj(Tcl_Interp *interp,
 			    Tcl_Obj *objPtr);
@@ -1089,8 +1089,6 @@ MODULE_SCOPE void	TclPushVarName(Tcl_Interp *interp,
 			    Tcl_Token *varTokenPtr, CompileEnv *envPtr,
 			    int flags, int *localIndexPtr,
 			    int *isScalarPtr);
-MODULE_SCOPE int	TclRegisterLiteral(CompileEnv *envPtr,
-			    char *bytes, int length, int flags);
 MODULE_SCOPE void	TclReleaseLiteral(Tcl_Interp *interp, Tcl_Obj *objPtr);
 MODULE_SCOPE void	TclInvalidateCmdLiteral(Tcl_Interp *interp, 
 			    const char *name, Namespace *nsPtr);
@@ -1181,6 +1179,21 @@ MODULE_SCOPE Tcl_Obj	*TclNewInstNameObj(unsigned char inst);
 	(envPtr)->currStackDepth += (delta);				\
     } while (0)
 
+#define TclGetStackDepth(envPtr)		\
+    ((envPtr)->currStackDepth)
+
+#define TclSetStackDepth(depth, envPtr)		\
+    (envPtr)->currStackDepth = (depth)
+
+#define TclCheckStackDepth(depth, envPtr)				\
+    do {								\
+	int dd = (depth);						\
+	if (dd != (envPtr)->currStackDepth) {				\
+	    Tcl_Panic("bad stack depth computations: is %i, should be %i", \
+		    (envPtr)->currStackDepth, dd);		\
+	}								\
+    } while (0)
+
 /*
  * Macro used to update the stack requirements. It is called by the macros
  * TclEmitOpCode, TclEmitInst1 and TclEmitInst4.
@@ -1321,6 +1334,18 @@ MODULE_SCOPE Tcl_Obj	*TclNewInstNameObj(unsigned char inst);
     } while (0)
 
 /*
+ * If the expr compiler finished with TRY_CONVERT, macro to remove it when the
+ * job is done by the following instruction.
+ */
+
+#define TclClearNumConversion(envPtr) \
+    do {								\
+	if (*(envPtr->codeNext - 1) == INST_TRY_CVT_TO_NUMERIC) {	\
+	    envPtr->codeNext--;						\
+	}								\
+    } while (0)
+
+/*
  * Macros to update a (signed or unsigned) integer starting at a pointer. The
  * two variants depend on the number of bytes. The ANSI C "prototypes" for
  * these macros are:
diff --git a/generic/tclInt.decls b/generic/tclInt.decls
index f0e907f..9f7b106 100644
--- a/generic/tclInt.decls
+++ b/generic/tclInt.decls
@@ -1006,6 +1006,12 @@ declare 249 {
 declare 250 {
     void TclSetSlaveCancelFlags(Tcl_Interp *interp, int flags, int force)
 }
+
+# Allow extensions for optimization
+declare 251 {
+    int TclRegisterLiteral(void *envPtr,
+	    char *bytes, int length, int flags)
+}
 
 ##############################################################################
 
diff --git a/generic/tclInt.h b/generic/tclInt.h
index ad17415..1ad32df 100644
--- a/generic/tclInt.h
+++ b/generic/tclInt.h
@@ -1809,7 +1809,14 @@ typedef struct Interp {
     ClientData interpInfo;	/* Information used by tclInterp.c to keep
 				 * track of master/slave interps on a
 				 * per-interp basis. */
-    Tcl_HashTable unused2;	/* No longer used (was mathFuncTable) */
+    union {
+	void (*optimizer)(void *envPtr);
+	Tcl_HashTable unused2;	/* No longer used (was mathFuncTable). The
+				 * unused space in interp was repurposed for
+				 * pluggable bytecode optimizers. The core
+				 * contains one optimizer, which can be
+				 * selectively overriden by extensions. */
+    } extra;
 
     /*
      * Information related to procedures and variables. See tclProc.c and
diff --git a/generic/tclIntDecls.h b/generic/tclIntDecls.h
index 47c6afd..f95f999 100644
--- a/generic/tclIntDecls.h
+++ b/generic/tclIntDecls.h
@@ -614,6 +614,9 @@ EXTERN char *		TclDoubleDigits(double dv, int ndigits, int flags,
 /* 250 */
 EXTERN void		TclSetSlaveCancelFlags(Tcl_Interp *interp, int flags,
 				int force);
+/* 251 */
+EXTERN int		TclRegisterLiteral(void *envPtr, char *bytes,
+				int length, int flags);
 
 typedef struct TclIntStubs {
     int magic;
@@ -870,6 +873,7 @@ typedef struct TclIntStubs {
     int (*tclCopyChannel) (Tcl_Interp *interp, Tcl_Channel inChan, Tcl_Channel outChan, Tcl_WideInt toRead, Tcl_Obj *cmdPtr); /* 248 */
     char * (*tclDoubleDigits) (double dv, int ndigits, int flags, int *decpt, int *signum, char **endPtr); /* 249 */
     void (*tclSetSlaveCancelFlags) (Tcl_Interp *interp, int flags, int force); /* 250 */
+    int (*tclRegisterLiteral) (void *envPtr, char *bytes, int length, int flags); /* 251 */
 } TclIntStubs;
 
 extern const TclIntStubs *tclIntStubsPtr;
@@ -1299,6 +1303,8 @@ extern const TclIntStubs *tclIntStubsPtr;
 	(tclIntStubsPtr->tclDoubleDigits) /* 249 */
 #define TclSetSlaveCancelFlags \
 	(tclIntStubsPtr->tclSetSlaveCancelFlags) /* 250 */
+#define TclRegisterLiteral \
+	(tclIntStubsPtr->tclRegisterLiteral) /* 251 */
 
 #endif /* defined(USE_TCL_STUBS) */
 
diff --git a/generic/tclLiteral.c b/generic/tclLiteral.c
index 11da6f8..2b0cc7e 100644
--- a/generic/tclLiteral.c
+++ b/generic/tclLiteral.c
@@ -358,7 +358,7 @@ TclFetchLiteral(
 
 int
 TclRegisterLiteral(
-    CompileEnv *envPtr,		/* Points to the CompileEnv in whose object
+    void *ePtr,		/* Points to the CompileEnv in whose object
 				 * array an object is found or created. */
     register char *bytes,	/* Points to string for which to find or
 				 * create an object in CompileEnv's object
@@ -372,6 +372,7 @@ TclRegisterLiteral(
 				 * the literal should not be shared accross
 				 * namespaces. */
 {
+    CompileEnv *envPtr = ePtr;
     Interp *iPtr = envPtr->iPtr;
     LiteralTable *localTablePtr = &envPtr->localLitTable;
     LiteralEntry *globalPtr, *localPtr;
diff --git a/generic/tclOptimize.c b/generic/tclOptimize.c
index 3196b83..827d89d 100644
--- a/generic/tclOptimize.c
+++ b/generic/tclOptimize.c
@@ -427,7 +427,7 @@ AdvanceJumps(
 
 void
 TclOptimizeBytecode(
-    CompileEnv *envPtr)
+    void *envPtr)
 {
     ConvertZeroEffectToNOP(envPtr);
     AdvanceJumps(envPtr);
diff --git a/generic/tclStubInit.c b/generic/tclStubInit.c
index 3f1c27b..e1918ef 100644
--- a/generic/tclStubInit.c
+++ b/generic/tclStubInit.c
@@ -551,6 +551,7 @@ static const TclIntStubs tclIntStubs = {
     TclCopyChannel, /* 248 */
     TclDoubleDigits, /* 249 */
     TclSetSlaveCancelFlags, /* 250 */
+    TclRegisterLiteral, /* 251 */
 };
 
 static const TclIntPlatStubs tclIntPlatStubs = {
diff --git a/tests/coroutine.test b/tests/coroutine.test
index 03c63ad..a360fd5 100644
--- a/tests/coroutine.test
+++ b/tests/coroutine.test
@@ -342,6 +342,9 @@ test coroutine-3.6 {info frame, bug #2910094} -setup {
     rename stack {}
     rename a {}
 } -result {}
+test coroutine-3.7 {bug 0b874c344d} {
+    dict get [coroutine X coroutine Y info frame 0] cmd
+} {coroutine X coroutine Y info frame 0}
 
 test coroutine-4.1 {bug #2093188} -setup {
     proc foo {} {
diff --git a/tools/man2help2.tcl b/tools/man2help2.tcl
index fe4e7ad..9c8f503 100644
--- a/tools/man2help2.tcl
+++ b/tools/man2help2.tcl
@@ -717,7 +717,7 @@ proc char {name} {
 	    textSetup
 	    puts -nonewline $file "\\'d7 "
 	}
-	{\(em} {
+	{\(em} - {\(en} {
 	    textSetup
 	    puts -nonewline $file "-"
 	}
diff --git a/tools/tcltk-man2html-utils.tcl b/tools/tcltk-man2html-utils.tcl
index bdd0079..8fd1245 100644
--- a/tools/tcltk-man2html-utils.tcl
+++ b/tools/tcltk-man2html-utils.tcl
@@ -142,6 +142,7 @@ proc process-text {text} {
 	    {\(+-}	"&#177;" \
 	    {\(co}	"&copy;" \
 	    {\(em}	"&#8212;" \
+	    {\(en}	"&#8211;" \
 	    {\(fm}	"&#8242;" \
 	    {\(mu}	"&#215;" \
 	    {\(mi}	"&#8722;" \