merge main working branch

1 files changed, 3146 insertions, 0 deletions

diff --git a/generic/tclCompCmdsGR.c b/generic/tclCompCmdsGR.c
new file mode 100644
index 0000000..b8a7e0f
--- /dev/null
+++ b/generic/tclCompCmdsGR.c
@@ -0,0 +1,3146 @@
+/*
+ * tclCompCmdsGR.c --
+ *
+ *	This file contains compilation procedures that compile various Tcl
+ *	commands (beginning with the letters 'g' through 'r') into a sequence
+ *	of instructions ("bytecodes").
+ *
+ * Copyright (c) 1997-1998 Sun Microsystems, Inc.
+ * Copyright (c) 2001 by Kevin B. Kenny.  All rights reserved.
+ * Copyright (c) 2002 ActiveState Corporation.
+ * Copyright (c) 2004-2013 by Donal K. Fellows.
+ *
+ * See the file "license.terms" for information on usage and redistribution of
+ * this file, and for a DISCLAIMER OF ALL WARRANTIES.
+ */
+
+#include "tclInt.h"
+#include "tclCompile.h"
+#include <assert.h>
+
+/*
+ * Prototypes for procedures defined later in this file:
+ */
+
+static void		CompileReturnInternal(CompileEnv *envPtr,
+			    unsigned char op, int code, int level,
+			    Tcl_Obj *returnOpts);
+static int		IndexTailVarIfKnown(Tcl_Interp *interp,
+			    Tcl_Token *varTokenPtr, CompileEnv *envPtr);
+
+#define INDEX_END	(-2)
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * GetIndexFromToken --
+ *
+ *	Parse a token and get the encoded version of the index (as understood
+ *	by TEBC), assuming it is at all knowable at compile time. Only handles
+ *	indices that are integers or 'end' or 'end-integer'.
+ *
+ * Returns:
+ *	TCL_OK if parsing succeeded, and TCL_ERROR if it failed.
+ *
+ * Side effects:
+ *	Sets *index to the index value if successful.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static inline int
+GetIndexFromToken(
+    Tcl_Token *tokenPtr,
+    int *index)
+{
+    Tcl_Obj *tmpObj = Tcl_NewObj();
+    int result, idx;
+
+    if (!TclWordKnownAtCompileTime(tokenPtr, tmpObj)) {
+	Tcl_DecrRefCount(tmpObj);
+	return TCL_ERROR;
+    }
+
+    result = TclGetIntFromObj(NULL, tmpObj, &idx);
+    if (result == TCL_OK) {
+	if (idx < 0) {
+	    result = TCL_ERROR;
+	}
+    } else {
+	result = TclGetIntForIndexM(NULL, tmpObj, INDEX_END, &idx);
+	if (result == TCL_OK && idx > INDEX_END) {
+	    result = TCL_ERROR;
+	}
+    }
+    Tcl_DecrRefCount(tmpObj);
+
+    if (result == TCL_OK) {
+	*index = idx;
+    }
+
+    return result;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclCompileGlobalCmd --
+ *
+ *	Procedure called to compile the "global" command.
+ *
+ * Results:
+ *	Returns TCL_OK for a successful compile. Returns TCL_ERROR to defer
+ *	evaluation to runtime.
+ *
+ * Side effects:
+ *	Instructions are added to envPtr to execute the "global" command at
+ *	runtime.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclCompileGlobalCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    Tcl_Token *varTokenPtr;
+    int localIndex, numWords, i;
+    DefineLineInformation;	/* TIP #280 */
+
+    /* TODO: Consider support for compiling expanded args. */
+    numWords = parsePtr->numWords;
+    if (numWords < 2) {
+	return TCL_ERROR;
+    }
+
+    /*
+     * 'global' has no effect outside of proc bodies; handle that at runtime
+     */
+
+    if (envPtr->procPtr == NULL) {
+	return TCL_ERROR;
+    }
+
+    /*
+     * Push the namespace
+     */
+
+    PushStringLiteral(envPtr, "::");
+
+    /*
+     * Loop over the variables.
+     */
+
+    varTokenPtr = TokenAfter(parsePtr->tokenPtr);
+    for (i=1; i<numWords; varTokenPtr = TokenAfter(varTokenPtr),i++) {
+	localIndex = IndexTailVarIfKnown(interp, varTokenPtr, envPtr);
+
+	if (localIndex < 0) {
+	    return TCL_ERROR;
+	}
+
+	/* TODO: Consider what value can pass throug the 
+	 * IndexTailVarIfKnown() screen.  Full CompileWord()
+	 * likely does not apply here.  Push known value instead. */
+	CompileWord(envPtr, varTokenPtr, interp, i);
+	TclEmitInstInt4(	INST_NSUPVAR, localIndex,	envPtr);
+    }
+
+    /*
+     * Pop the namespace, and set the result to empty
+     */
+
+    TclEmitOpcode(		INST_POP,			envPtr);
+    PushStringLiteral(envPtr, "");
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclCompileIfCmd --
+ *
+ *	Procedure called to compile the "if" command.
+ *
+ * Results:
+ *	Returns TCL_OK for a successful compile. Returns TCL_ERROR to defer
+ *	evaluation to runtime.
+ *
+ * Side effects:
+ *	Instructions are added to envPtr to execute the "if" command at
+ *	runtime.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclCompileIfCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    JumpFixupArray jumpFalseFixupArray;
+				/* Used to fix the ifFalse jump after each
+				 * test when its target PC is determined. */
+    JumpFixupArray jumpEndFixupArray;
+				/* Used to fix the jump after each "then" body
+				 * to the end of the "if" when that PC is
+				 * determined. */
+    Tcl_Token *tokenPtr, *testTokenPtr;
+    int jumpIndex = 0;		/* Avoid compiler warning. */
+    int jumpFalseDist, numWords, wordIdx, numBytes, j, code;
+    const char *word;
+    int realCond = 1;		/* Set to 0 for static conditions:
+				 * "if 0 {..}" */
+    int boolVal;		/* Value of static condition. */
+    int compileScripts = 1;
+    DefineLineInformation;	/* TIP #280 */
+
+    /*
+     * Only compile the "if" command if all arguments are simple words, in
+     * order to insure correct substitution [Bug 219166]
+     */
+
+    tokenPtr = parsePtr->tokenPtr;
+    wordIdx = 0;
+    numWords = parsePtr->numWords;
+
+    for (wordIdx = 0; wordIdx < numWords; wordIdx++) {
+	if (tokenPtr->type != TCL_TOKEN_SIMPLE_WORD) {
+	    return TCL_ERROR;
+	}
+	tokenPtr = TokenAfter(tokenPtr);
+    }
+
+    TclInitJumpFixupArray(&jumpFalseFixupArray);
+    TclInitJumpFixupArray(&jumpEndFixupArray);
+    code = TCL_OK;
+
+    /*
+     * Each iteration of this loop compiles one "if expr ?then? body" or
+     * "elseif expr ?then? body" clause.
+     */
+
+    tokenPtr = parsePtr->tokenPtr;
+    wordIdx = 0;
+    while (wordIdx < numWords) {
+	/*
+	 * Stop looping if the token isn't "if" or "elseif".
+	 */
+
+	word = tokenPtr[1].start;
+	numBytes = tokenPtr[1].size;
+	if ((tokenPtr == parsePtr->tokenPtr)
+		|| ((numBytes == 6) && (strncmp(word, "elseif", 6) == 0))) {
+	    tokenPtr = TokenAfter(tokenPtr);
+	    wordIdx++;
+	} else {
+	    break;
+	}
+	if (wordIdx >= numWords) {
+	    code = TCL_ERROR;
+	    goto done;
+	}
+
+	/*
+	 * Compile the test expression then emit the conditional jump around
+	 * the "then" part.
+	 */
+
+	testTokenPtr = tokenPtr;
+
+	if (realCond) {
+	    /*
+	     * Find out if the condition is a constant.
+	     */
+
+	    Tcl_Obj *boolObj = Tcl_NewStringObj(testTokenPtr[1].start,
+		    testTokenPtr[1].size);
+
+	    Tcl_IncrRefCount(boolObj);
+	    code = Tcl_GetBooleanFromObj(NULL, boolObj, &boolVal);
+	    TclDecrRefCount(boolObj);
+	    if (code == TCL_OK) {
+		/*
+		 * A static condition.
+		 */
+
+		realCond = 0;
+		if (!boolVal) {
+		    compileScripts = 0;
+		}
+	    } else {
+		SetLineInformation(wordIdx);
+		Tcl_ResetResult(interp);
+		TclCompileExprWords(interp, testTokenPtr, 1, envPtr);
+		TclClearNumConversion(envPtr);
+		if (jumpFalseFixupArray.next >= jumpFalseFixupArray.end) {
+		    TclExpandJumpFixupArray(&jumpFalseFixupArray);
+		}
+		jumpIndex = jumpFalseFixupArray.next;
+		jumpFalseFixupArray.next++;
+		TclEmitForwardJump(envPtr, TCL_FALSE_JUMP,
+			jumpFalseFixupArray.fixup+jumpIndex);
+	    }
+	    code = TCL_OK;
+	}
+
+	/*
+	 * Skip over the optional "then" before the then clause.
+	 */
+
+	tokenPtr = TokenAfter(testTokenPtr);
+	wordIdx++;
+	if (wordIdx >= numWords) {
+	    code = TCL_ERROR;
+	    goto done;
+	}
+	if (tokenPtr->type == TCL_TOKEN_SIMPLE_WORD) {
+	    word = tokenPtr[1].start;
+	    numBytes = tokenPtr[1].size;
+	    if ((numBytes == 4) && (strncmp(word, "then", 4) == 0)) {
+		tokenPtr = TokenAfter(tokenPtr);
+		wordIdx++;
+		if (wordIdx >= numWords) {
+		    code = TCL_ERROR;
+		    goto done;
+		}
+	    }
+	}
+
+	/*
+	 * Compile the "then" command body.
+	 */
+
+	if (compileScripts) {
+	    BODY(tokenPtr, wordIdx);
+	}
+
+	if (realCond) {
+	    /*
+	     * Jump to the end of the "if" command. Both jumpFalseFixupArray
+	     * and jumpEndFixupArray are indexed by "jumpIndex".
+	     */
+
+	    if (jumpEndFixupArray.next >= jumpEndFixupArray.end) {
+		TclExpandJumpFixupArray(&jumpEndFixupArray);
+	    }
+	    jumpEndFixupArray.next++;
+	    TclEmitForwardJump(envPtr, TCL_UNCONDITIONAL_JUMP,
+		    jumpEndFixupArray.fixup+jumpIndex);
+
+	    /*
+	     * Fix the target of the jumpFalse after the test. Generate a 4
+	     * byte jump if the distance is > 120 bytes. This is conservative,
+	     * and ensures that we won't have to replace this jump if we later
+	     * also need to replace the proceeding jump to the end of the "if"
+	     * with a 4 byte jump.
+	     */
+
+	    TclAdjustStackDepth(-1, envPtr);
+	    if (TclFixupForwardJumpToHere(envPtr,
+		    jumpFalseFixupArray.fixup+jumpIndex, 120)) {
+		/*
+		 * Adjust the code offset for the proceeding jump to the end
+		 * of the "if" command.
+		 */
+
+		jumpEndFixupArray.fixup[jumpIndex].codeOffset += 3;
+	    }
+	} else if (boolVal) {
+	    /*
+	     * We were processing an "if 1 {...}"; stop compiling scripts.
+	     */
+
+	    compileScripts = 0;
+	} else {
+	    /*
+	     * We were processing an "if 0 {...}"; reset so that the rest
+	     * (elseif, else) is compiled correctly.
+	     */
+
+	    realCond = 1;
+	    compileScripts = 1;
+	}
+
+	tokenPtr = TokenAfter(tokenPtr);
+	wordIdx++;
+    }
+
+    /*
+     * Check for the optional else clause. Do not compile anything if this was
+     * an "if 1 {...}" case.
+     */
+
+    if ((wordIdx < numWords) && (tokenPtr->type == TCL_TOKEN_SIMPLE_WORD)) {
+	/*
+	 * There is an else clause. Skip over the optional "else" word.
+	 */
+
+	word = tokenPtr[1].start;
+	numBytes = tokenPtr[1].size;
+	if ((numBytes == 4) && (strncmp(word, "else", 4) == 0)) {
+	    tokenPtr = TokenAfter(tokenPtr);
+	    wordIdx++;
+	    if (wordIdx >= numWords) {
+		code = TCL_ERROR;
+		goto done;
+	    }
+	}
+
+	if (compileScripts) {
+	    /*
+	     * Compile the else command body.
+	     */
+
+	    BODY(tokenPtr, wordIdx);
+	}
+
+	/*
+	 * Make sure there are no words after the else clause.
+	 */
+
+	wordIdx++;
+	if (wordIdx < numWords) {
+	    code = TCL_ERROR;
+	    goto done;
+	}
+    } else {
+	/*
+	 * No else clause: the "if" command's result is an empty string.
+	 */
+
+	if (compileScripts) {
+	    PushStringLiteral(envPtr, "");
+	}
+    }
+
+    /*
+     * Fix the unconditional jumps to the end of the "if" command.
+     */
+
+    for (j = jumpEndFixupArray.next;  j > 0;  j--) {
+	jumpIndex = (j - 1);	/* i.e. process the closest jump first. */
+	if (TclFixupForwardJumpToHere(envPtr,
+		jumpEndFixupArray.fixup+jumpIndex, 127)) {
+	    /*
+	     * Adjust the immediately preceeding "ifFalse" jump. We moved it's
+	     * target (just after this jump) down three bytes.
+	     */
+
+	    unsigned char *ifFalsePc = envPtr->codeStart
+		    + jumpFalseFixupArray.fixup[jumpIndex].codeOffset;
+	    unsigned char opCode = *ifFalsePc;
+
+	    if (opCode == INST_JUMP_FALSE1) {
+		jumpFalseDist = TclGetInt1AtPtr(ifFalsePc + 1);
+		jumpFalseDist += 3;
+		TclStoreInt1AtPtr(jumpFalseDist, (ifFalsePc + 1));
+	    } else if (opCode == INST_JUMP_FALSE4) {
+		jumpFalseDist = TclGetInt4AtPtr(ifFalsePc + 1);
+		jumpFalseDist += 3;
+		TclStoreInt4AtPtr(jumpFalseDist, (ifFalsePc + 1));
+	    } else {
+		Tcl_Panic("TclCompileIfCmd: unexpected opcode \"%d\" updating ifFalse jump", (int) opCode);
+	    }
+	}
+    }
+
+    /*
+     * Free the jumpFixupArray array if malloc'ed storage was used.
+     */
+
+  done:
+    TclFreeJumpFixupArray(&jumpFalseFixupArray);
+    TclFreeJumpFixupArray(&jumpEndFixupArray);
+    return code;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclCompileIncrCmd --
+ *
+ *	Procedure called to compile the "incr" command.
+ *
+ * Results:
+ *	Returns TCL_OK for a successful compile. Returns TCL_ERROR to defer
+ *	evaluation to runtime.
+ *
+ * Side effects:
+ *	Instructions are added to envPtr to execute the "incr" command at
+ *	runtime.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclCompileIncrCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    Tcl_Token *varTokenPtr, *incrTokenPtr;
+    int isScalar, localIndex, haveImmValue, immValue;
+    DefineLineInformation;	/* TIP #280 */
+
+    if ((parsePtr->numWords != 2) && (parsePtr->numWords != 3)) {
+	return TCL_ERROR;
+    }
+
+    varTokenPtr = TokenAfter(parsePtr->tokenPtr);
+
+    PushVarNameWord(interp, varTokenPtr, envPtr, TCL_NO_LARGE_INDEX,
+	    &localIndex, &isScalar, 1);
+
+    /*
+     * If an increment is given, push it, but see first if it's a small
+     * integer.
+     */
+
+    haveImmValue = 0;
+    immValue = 1;
+    if (parsePtr->numWords == 3) {
+	incrTokenPtr = TokenAfter(varTokenPtr);
+	if (incrTokenPtr->type == TCL_TOKEN_SIMPLE_WORD) {
+	    const char *word = incrTokenPtr[1].start;
+	    int numBytes = incrTokenPtr[1].size;
+	    int code;
+	    Tcl_Obj *intObj = Tcl_NewStringObj(word, numBytes);
+
+	    Tcl_IncrRefCount(intObj);
+	    code = TclGetIntFromObj(NULL, intObj, &immValue);
+	    TclDecrRefCount(intObj);
+	    if ((code == TCL_OK) && (-127 <= immValue) && (immValue <= 127)) {
+		haveImmValue = 1;
+	    }
+	    if (!haveImmValue) {
+		PushLiteral(envPtr, word, numBytes);
+	    }
+	} else {
+	    SetLineInformation(2);
+	    CompileTokens(envPtr, incrTokenPtr, interp);
+	    TclClearNumConversion(envPtr);
+	}
+    } else {			/* No incr amount given so use 1. */
+	haveImmValue = 1;
+    }
+
+    /*
+     * Emit the instruction to increment the variable.
+     */
+
+    if (isScalar) {	/* Simple scalar variable. */
+	if (localIndex >= 0) {
+	    if (haveImmValue) {
+		TclEmitInstInt1(INST_INCR_SCALAR1_IMM, localIndex, envPtr);
+		TclEmitInt1(immValue, envPtr);
+	    } else {
+		TclEmitInstInt1(INST_INCR_SCALAR1, localIndex,	envPtr);
+	    }
+	} else {
+	    if (haveImmValue) {
+		TclEmitInstInt1(INST_INCR_STK_IMM, immValue, envPtr);
+	    } else {
+		TclEmitOpcode(	INST_INCR_STK,		envPtr);
+	    }
+	}
+    } else {			/* Simple array variable. */
+	if (localIndex >= 0) {
+	    if (haveImmValue) {
+		TclEmitInstInt1(INST_INCR_ARRAY1_IMM, localIndex, envPtr);
+		TclEmitInt1(immValue, envPtr);
+	    } else {
+		TclEmitInstInt1(INST_INCR_ARRAY1, localIndex,	envPtr);
+	    }
+	} else {
+	    if (haveImmValue) {
+		TclEmitInstInt1(INST_INCR_ARRAY_STK_IMM, immValue, envPtr);
+	    } else {
+		TclEmitOpcode(	INST_INCR_ARRAY_STK,		envPtr);
+	    }
+	}
+    }
+
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclCompileInfo*Cmd --
+ *
+ *	Procedures called to compile "info" subcommands.
+ *
+ * Results:
+ *	Returns TCL_OK for a successful compile. Returns TCL_ERROR to defer
+ *	evaluation to runtime.
+ *
+ * Side effects:
+ *	Instructions are added to envPtr to execute the "info" subcommand at
+ *	runtime.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclCompileInfoCommandsCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)
+{
+    DefineLineInformation;	/* TIP #280 */
+    Tcl_Token *tokenPtr;
+    Tcl_Obj *objPtr;
+    char *bytes;
+
+    /*
+     * We require one compile-time known argument for the case we can compile.
+     */
+
+    if (parsePtr->numWords == 1) {
+	return TclCompileBasic0ArgCmd(interp, parsePtr, cmdPtr, envPtr);
+    } else if (parsePtr->numWords != 2) {
+	return TCL_ERROR;
+    }
+    tokenPtr = TokenAfter(parsePtr->tokenPtr);
+    objPtr = Tcl_NewObj();
+    Tcl_IncrRefCount(objPtr);
+    if (!TclWordKnownAtCompileTime(tokenPtr, objPtr)) {
+	goto notCompilable;
+    }
+    bytes = Tcl_GetString(objPtr);
+
+    /*
+     * We require that the argument start with "::" and not have any of "*\[?"
+     * in it. (Theoretically, we should look in only the final component, but
+     * the difference is so slight given current naming practices.)
+     */
+
+    if (bytes[0] != ':' || bytes[1] != ':' || !TclMatchIsTrivial(bytes)) {
+	goto notCompilable;
+    }
+    Tcl_DecrRefCount(objPtr);
+
+    /*
+     * Confirmed as a literal that will not frighten the horses. Compile. Note
+     * that the result needs to be list-ified.
+     */
+
+    /* TODO: Just push the known value */
+    CompileWord(envPtr, tokenPtr,		interp, 1);
+    TclEmitOpcode(	INST_RESOLVE_COMMAND,	envPtr);
+    TclEmitOpcode(	INST_DUP,		envPtr);
+    TclEmitOpcode(	INST_STR_LEN,		envPtr);
+    TclEmitInstInt1(	INST_JUMP_FALSE1, 7,	envPtr);
+    TclEmitInstInt4(	INST_LIST, 1,		envPtr);
+    return TCL_OK;
+
+  notCompilable:
+    Tcl_DecrRefCount(objPtr);
+    return TclCompileBasic1ArgCmd(interp, parsePtr, cmdPtr, envPtr);
+}
+
+int
+TclCompileInfoCoroutineCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    /*
+     * Only compile [info coroutine] without arguments.
+     */
+
+    if (parsePtr->numWords != 1) {
+	return TCL_ERROR;
+    }
+
+    /*
+     * Not much to do; we compile to a single instruction...
+     */
+
+    TclEmitOpcode(		INST_COROUTINE_NAME,		envPtr);
+    return TCL_OK;
+}
+
+int
+TclCompileInfoExistsCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    Tcl_Token *tokenPtr;
+    int isScalar, localIndex;
+    DefineLineInformation;	/* TIP #280 */
+
+    if (parsePtr->numWords != 2) {
+	return TCL_ERROR;
+    }
+
+    /*
+     * Decide if we can use a frame slot for the var/array name or if we need
+     * to emit code to compute and push the name at runtime. We use a frame
+     * slot (entry in the array of local vars) if we are compiling a procedure
+     * body and if the name is simple text that does not include namespace
+     * qualifiers.
+     */
+
+    tokenPtr = TokenAfter(parsePtr->tokenPtr);
+    PushVarNameWord(interp, tokenPtr, envPtr, 0, &localIndex, &isScalar, 1);
+
+    /*
+     * Emit instruction to check the variable for existence.
+     */
+
+    if (isScalar) {
+	if (localIndex < 0) {
+	    TclEmitOpcode(	INST_EXIST_STK,			envPtr);
+	} else {
+	    TclEmitInstInt4(	INST_EXIST_SCALAR, localIndex,	envPtr);
+	}
+    } else {
+	if (localIndex < 0) {
+	    TclEmitOpcode(	INST_EXIST_ARRAY_STK,		envPtr);
+	} else {
+	    TclEmitInstInt4(	INST_EXIST_ARRAY, localIndex,	envPtr);
+	}
+    }
+
+    return TCL_OK;
+}
+
+int
+TclCompileInfoLevelCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    /*
+     * Only compile [info level] without arguments or with a single argument.
+     */
+
+    if (parsePtr->numWords == 1) {
+	/*
+	 * Not much to do; we compile to a single instruction...
+	 */
+
+	TclEmitOpcode(		INST_INFO_LEVEL_NUM,		envPtr);
+    } else if (parsePtr->numWords != 2) {
+	return TCL_ERROR;
+    } else {
+	DefineLineInformation;	/* TIP #280 */
+
+	/*
+	 * Compile the argument, then add the instruction to convert it into a
+	 * list of arguments.
+	 */
+
+	CompileWord(envPtr, TokenAfter(parsePtr->tokenPtr), interp, 1);
+	TclEmitOpcode(		INST_INFO_LEVEL_ARGS,		envPtr);
+    }
+    return TCL_OK;
+}
+
+int
+TclCompileInfoObjectClassCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)
+{
+    DefineLineInformation;	/* TIP #280 */
+    Tcl_Token *tokenPtr = TokenAfter(parsePtr->tokenPtr);
+
+    if (parsePtr->numWords != 2) {
+	return TCL_ERROR;
+    }
+    CompileWord(envPtr,		tokenPtr,		interp, 1);
+    TclEmitOpcode(		INST_TCLOO_CLASS,	envPtr);
+    return TCL_OK;
+}
+
+int
+TclCompileInfoObjectIsACmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)
+{
+    DefineLineInformation;	/* TIP #280 */
+    Tcl_Token *tokenPtr = TokenAfter(parsePtr->tokenPtr);
+
+    /*
+     * We only handle [info object isa object <somevalue>]. The first three
+     * words are compressed to a single token by the ensemble compilation
+     * engine.
+     */
+
+    if (parsePtr->numWords != 3) {
+	return TCL_ERROR;
+    }
+    if (tokenPtr->type != TCL_TOKEN_SIMPLE_WORD || tokenPtr[1].size < 1
+	    || strncmp(tokenPtr[1].start, "object", tokenPtr[1].size)) {
+	return TCL_ERROR;
+    }
+    tokenPtr = TokenAfter(tokenPtr);
+
+    /*
+     * Issue the code.
+     */
+
+    CompileWord(envPtr,		tokenPtr,		interp, 2);
+    TclEmitOpcode(		INST_TCLOO_IS_OBJECT,	envPtr);
+    return TCL_OK;
+}
+
+int
+TclCompileInfoObjectNamespaceCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)
+{
+    DefineLineInformation;	/* TIP #280 */
+    Tcl_Token *tokenPtr = TokenAfter(parsePtr->tokenPtr);
+
+    if (parsePtr->numWords != 2) {
+	return TCL_ERROR;
+    }
+    CompileWord(envPtr,		tokenPtr,		interp, 1);
+    TclEmitOpcode(		INST_TCLOO_NS,		envPtr);
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclCompileLappendCmd --
+ *
+ *	Procedure called to compile the "lappend" command.
+ *
+ * Results:
+ *	Returns TCL_OK for a successful compile. Returns TCL_ERROR to defer
+ *	evaluation to runtime.
+ *
+ * Side effects:
+ *	Instructions are added to envPtr to execute the "lappend" command at
+ *	runtime.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclCompileLappendCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    Tcl_Token *varTokenPtr, *valueTokenPtr;
+    int isScalar, localIndex, numWords, i, fwd, offsetFwd;
+    DefineLineInformation;	/* TIP #280 */
+
+    /*
+     * If we're not in a procedure, don't compile.
+     */
+
+    if (envPtr->procPtr == NULL) {
+	return TCL_ERROR;
+    }
+
+    /* TODO: Consider support for compiling expanded args. */
+    numWords = parsePtr->numWords;
+    if (numWords == 1) {
+	return TCL_ERROR;
+    }
+    if (numWords != 3) {
+	/*
+	 * LAPPEND instructions currently only handle one value, but we can
+	 * handle some multi-value cases by stringing them together.
+	 */
+
+	goto lappendMultiple;
+    }
+
+    /*
+     * Decide if we can use a frame slot for the var/array name or if we
+     * need to emit code to compute and push the name at runtime. We use a
+     * frame slot (entry in the array of local vars) if we are compiling a
+     * procedure body and if the name is simple text that does not include
+     * namespace qualifiers.
+     */
+
+    varTokenPtr = TokenAfter(parsePtr->tokenPtr);
+
+    PushVarNameWord(interp, varTokenPtr, envPtr, 0,
+	    &localIndex, &isScalar, 1);
+
+    /*
+     * If we are doing an assignment, push the new value. In the no values
+     * case, create an empty object.
+     */
+
+    if (numWords > 2) {
+	Tcl_Token *valueTokenPtr = TokenAfter(varTokenPtr);
+
+	CompileWord(envPtr, valueTokenPtr, interp, 2);
+    }
+
+    /*
+     * Emit instructions to set/get the variable.
+     */
+
+    /*
+     * The *_STK opcodes should be refactored to make better use of existing
+     * LOAD/STORE instructions.
+     */
+
+    if (isScalar) {
+	if (localIndex < 0) {
+	    TclEmitOpcode(	INST_LAPPEND_STK,		envPtr);
+	} else {
+	    Emit14Inst(		INST_LAPPEND_SCALAR, localIndex, envPtr);
+	}
+    } else {
+	if (localIndex < 0) {
+	    TclEmitOpcode(	INST_LAPPEND_ARRAY_STK,		envPtr);
+	} else {
+	    Emit14Inst(		INST_LAPPEND_ARRAY, localIndex,	envPtr);
+	}
+    }
+
+    return TCL_OK;
+
+  lappendMultiple:
+    /*
+     * Can only handle the case where we are appending to a local scalar when
+     * there are multiple values to append.  Fortunately, this is common.
+     */
+
+    if (envPtr->procPtr == NULL) {
+	return TCL_ERROR;
+    }
+    varTokenPtr = TokenAfter(parsePtr->tokenPtr);
+    PushVarNameWord(interp, varTokenPtr, envPtr, TCL_NO_ELEMENT,
+	    &localIndex, &isScalar, 1);
+    if (!isScalar || localIndex < 0) {
+	return TCL_ERROR;
+    }
+
+    /*
+     * Definitely appending to a local scalar; generate the words and append
+     * them.
+     */
+
+    valueTokenPtr = TokenAfter(varTokenPtr);
+    for (i = 2 ; i < numWords ; i++) {
+	CompileWord(envPtr, valueTokenPtr, interp, i);
+	valueTokenPtr = TokenAfter(valueTokenPtr);
+    }
+    TclEmitInstInt4(	  INST_LIST, numWords-2,		envPtr);
+    TclEmitInstInt4(	  INST_EXIST_SCALAR, localIndex,	envPtr);
+    offsetFwd = CurrentOffset(envPtr);
+    TclEmitInstInt1(	  INST_JUMP_FALSE1, 0,			envPtr);
+    Emit14Inst(		  INST_LOAD_SCALAR, localIndex,		envPtr);
+    TclEmitInstInt4(	  INST_REVERSE, 2,			envPtr);
+    TclEmitOpcode(	  INST_LIST_CONCAT,			envPtr);
+    fwd = CurrentOffset(envPtr) - offsetFwd;
+    TclStoreInt1AtPtr(fwd, envPtr->codeStart+offsetFwd+1);
+    Emit14Inst(		  INST_STORE_SCALAR, localIndex,	envPtr);
+
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclCompileLassignCmd --
+ *
+ *	Procedure called to compile the "lassign" command.
+ *
+ * Results:
+ *	Returns TCL_OK for a successful compile. Returns TCL_ERROR to defer
+ *	evaluation to runtime.
+ *
+ * Side effects:
+ *	Instructions are added to envPtr to execute the "lassign" command at
+ *	runtime.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclCompileLassignCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    Tcl_Token *tokenPtr;
+    int isScalar, localIndex, numWords, idx;
+    DefineLineInformation;	/* TIP #280 */
+
+    numWords = parsePtr->numWords;
+
+    /*
+     * Check for command syntax error, but we'll punt that to runtime.
+     */
+
+    if (numWords < 3) {
+	return TCL_ERROR;
+    }
+
+    /*
+     * Generate code to push list being taken apart by [lassign].
+     */
+
+    tokenPtr = TokenAfter(parsePtr->tokenPtr);
+    CompileWord(envPtr, tokenPtr, interp, 1);
+
+    /*
+     * Generate code to assign values from the list to variables.
+     */
+
+    for (idx=0 ; idx<numWords-2 ; idx++) {
+	tokenPtr = TokenAfter(tokenPtr);
+
+	/*
+	 * Generate the next variable name.
+	 */
+
+	PushVarNameWord(interp, tokenPtr, envPtr, 0, &localIndex,
+		&isScalar, idx+2);
+
+	/*
+	 * Emit instructions to get the idx'th item out of the list value on
+	 * the stack and assign it to the variable.
+	 */
+
+	if (isScalar) {
+	    if (localIndex >= 0) {
+		TclEmitOpcode(	INST_DUP,			envPtr);
+		TclEmitInstInt4(INST_LIST_INDEX_IMM, idx,	envPtr);
+		Emit14Inst(	INST_STORE_SCALAR, localIndex,	envPtr);
+		TclEmitOpcode(	INST_POP,			envPtr);
+	    } else {
+		TclEmitInstInt4(INST_OVER, 1,			envPtr);
+		TclEmitInstInt4(INST_LIST_INDEX_IMM, idx,	envPtr);
+		TclEmitOpcode(	INST_STORE_STK,			envPtr);
+		TclEmitOpcode(	INST_POP,			envPtr);
+	    }
+	} else {
+	    if (localIndex >= 0) {
+		TclEmitInstInt4(INST_OVER, 1,			envPtr);
+		TclEmitInstInt4(INST_LIST_INDEX_IMM, idx,	envPtr);
+		Emit14Inst(	INST_STORE_ARRAY, localIndex,	envPtr);
+		TclEmitOpcode(	INST_POP,			envPtr);
+	    } else {
+		TclEmitInstInt4(INST_OVER, 2,			envPtr);
+		TclEmitInstInt4(INST_LIST_INDEX_IMM, idx,	envPtr);
+		TclEmitOpcode(	INST_STORE_ARRAY_STK,		envPtr);
+		TclEmitOpcode(	INST_POP,			envPtr);
+	    }
+	}
+    }
+
+    /*
+     * Generate code to leave the rest of the list on the stack.
+     */
+
+    TclEmitInstInt4(		INST_LIST_RANGE_IMM, idx,	envPtr);
+    TclEmitInt4(			INDEX_END,		envPtr);
+
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclCompileLindexCmd --
+ *
+ *	Procedure called to compile the "lindex" command.
+ *
+ * Results:
+ *	Returns TCL_OK for a successful compile. Returns TCL_ERROR to defer
+ *	evaluation to runtime.
+ *
+ * Side effects:
+ *	Instructions are added to envPtr to execute the "lindex" command at
+ *	runtime.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclCompileLindexCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    Tcl_Token *idxTokenPtr, *valTokenPtr;
+    int i, idx, numWords = parsePtr->numWords;
+    DefineLineInformation;	/* TIP #280 */
+
+    /*
+     * Quit if too few args.
+     */
+
+    /* TODO: Consider support for compiling expanded args. */
+    if (numWords <= 1) {
+	return TCL_ERROR;
+    }
+
+    valTokenPtr = TokenAfter(parsePtr->tokenPtr);
+    if (numWords != 3) {
+	goto emitComplexLindex;
+    }
+
+    idxTokenPtr = TokenAfter(valTokenPtr);
+    if (GetIndexFromToken(idxTokenPtr, &idx) == TCL_OK) {
+	/*
+	 * All checks have been completed, and we have exactly one of these
+	 * constructs:
+	 *	 lindex <arbitraryValue> <posInt>
+	 *	 lindex <arbitraryValue> end-<posInt>
+	 * This is best compiled as a push of the arbitrary value followed by
+	 * an "immediate lindex" which is the most efficient variety.
+	 */
+
+	CompileWord(envPtr, valTokenPtr, interp, 1);
+	TclEmitInstInt4(	INST_LIST_INDEX_IMM, idx,	envPtr);
+	return TCL_OK;
+    }
+
+    /*
+     * If the value was not known at compile time, the conversion failed or
+     * the value was negative, we just keep on going with the more complex
+     * compilation.
+     */
+
+    /*
+     * Push the operands onto the stack.
+     */
+
+  emitComplexLindex:
+    for (i=1 ; i<numWords ; i++) {
+	CompileWord(envPtr, valTokenPtr, interp, i);
+	valTokenPtr = TokenAfter(valTokenPtr);
+    }
+
+    /*
+     * Emit INST_LIST_INDEX if objc==3, or INST_LIST_INDEX_MULTI if there are
+     * multiple index args.
+     */
+
+    if (numWords == 3) {
+	TclEmitOpcode(		INST_LIST_INDEX,		envPtr);
+    } else {
+	TclEmitInstInt4(	INST_LIST_INDEX_MULTI, numWords-1, envPtr);
+    }
+
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclCompileListCmd --
+ *
+ *	Procedure called to compile the "list" command.
+ *
+ * Results:
+ *	Returns TCL_OK for a successful compile. Returns TCL_ERROR to defer
+ *	evaluation to runtime.
+ *
+ * Side effects:
+ *	Instructions are added to envPtr to execute the "list" command at
+ *	runtime.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclCompileListCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    DefineLineInformation;	/* TIP #280 */
+    Tcl_Token *valueTokenPtr;
+    int i, numWords, concat, build;
+    Tcl_Obj *listObj, *objPtr;
+
+    if (parsePtr->numWords == 1) {
+	/*
+	 * [list] without arguments just pushes an empty object.
+	 */
+
+	PushStringLiteral(envPtr, "");
+	return TCL_OK;
+    }
+
+    /*
+     * Test if all arguments are compile-time known. If they are, we can
+     * implement with a simple push.
+     */
+
+    numWords = parsePtr->numWords;
+    valueTokenPtr = TokenAfter(parsePtr->tokenPtr);
+    listObj = Tcl_NewObj();
+    for (i = 1; i < numWords && listObj != NULL; i++) {
+	objPtr = Tcl_NewObj();
+	if (TclWordKnownAtCompileTime(valueTokenPtr, objPtr)) {
+	    (void) Tcl_ListObjAppendElement(NULL, listObj, objPtr);
+	} else {
+	    Tcl_DecrRefCount(objPtr);
+	    Tcl_DecrRefCount(listObj);
+	    listObj = NULL;
+	}
+	valueTokenPtr = TokenAfter(valueTokenPtr);
+    }
+    if (listObj != NULL) {
+	int len;
+	const char *bytes = Tcl_GetStringFromObj(listObj, &len);
+
+	PushLiteral(envPtr, bytes, len);
+	Tcl_DecrRefCount(listObj);
+	if (len > 0) {
+	    /*
+	     * Force list interpretation!
+	     */
+
+	    TclEmitOpcode(	INST_DUP,		envPtr);
+	    TclEmitOpcode(	INST_LIST_LENGTH,	envPtr);
+	    TclEmitOpcode(	INST_POP,		envPtr);
+	}
+	return TCL_OK;
+    }
+
+    /*
+     * Push the all values onto the stack.
+     */
+
+    numWords = parsePtr->numWords;
+    valueTokenPtr = TokenAfter(parsePtr->tokenPtr);
+    concat = build = 0;
+    for (i = 1; i < numWords; i++) {
+	if (valueTokenPtr->type == TCL_TOKEN_EXPAND_WORD && build > 0) {
+	    TclEmitInstInt4(	INST_LIST, build,	envPtr);
+	    if (concat) {
+		TclEmitOpcode(	INST_LIST_CONCAT,	envPtr);
+	    }
+	    build = 0;
+	    concat = 1;
+	}
+	CompileWord(envPtr, valueTokenPtr, interp, i);
+	if (valueTokenPtr->type == TCL_TOKEN_EXPAND_WORD) {
+	    if (concat) {
+		TclEmitOpcode(	INST_LIST_CONCAT,	envPtr);
+	    } else {
+		concat = 1;
+	    }
+	} else {
+	    build++;
+	}
+	valueTokenPtr = TokenAfter(valueTokenPtr);
+    }
+    if (build > 0) {
+	TclEmitInstInt4(	INST_LIST, build,	envPtr);
+	if (concat) {
+	    TclEmitOpcode(	INST_LIST_CONCAT,	envPtr);
+	}
+    }
+
+    /*
+     * If there was just one expanded word, we must ensure that it is a list
+     * at this point. We use an [lrange ... 0 end] for this (instead of
+     * [llength], as with literals) as we must drop any string representation
+     * that might be hanging around.
+     */
+
+    if (concat && numWords == 2) {
+	TclEmitInstInt4(	INST_LIST_RANGE_IMM, 0,	envPtr);
+	TclEmitInt4(			INDEX_END,	envPtr);
+    }
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclCompileLlengthCmd --
+ *
+ *	Procedure called to compile the "llength" command.
+ *
+ * Results:
+ *	Returns TCL_OK for a successful compile. Returns TCL_ERROR to defer
+ *	evaluation to runtime.
+ *
+ * Side effects:
+ *	Instructions are added to envPtr to execute the "llength" command at
+ *	runtime.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclCompileLlengthCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    Tcl_Token *varTokenPtr;
+    DefineLineInformation;	/* TIP #280 */
+
+    if (parsePtr->numWords != 2) {
+	return TCL_ERROR;
+    }
+    varTokenPtr = TokenAfter(parsePtr->tokenPtr);
+
+    CompileWord(envPtr, varTokenPtr, interp, 1);
+    TclEmitOpcode(		INST_LIST_LENGTH,		envPtr);
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclCompileLrangeCmd --
+ *
+ *	How to compile the "lrange" command. We only bother because we needed
+ *	the opcode anyway for "lassign".
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclCompileLrangeCmd(
+    Tcl_Interp *interp,		/* Tcl interpreter for context. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the
+				 * command. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds the resulting instructions. */
+{
+    Tcl_Token *tokenPtr, *listTokenPtr;
+    DefineLineInformation;	/* TIP #280 */
+    int idx1, idx2;
+
+    if (parsePtr->numWords != 4) {
+	return TCL_ERROR;
+    }
+    listTokenPtr = TokenAfter(parsePtr->tokenPtr);
+
+    /*
+     * Parse the indices. Will only compile if both are constants and not an
+     * _integer_ less than zero (since we reserve negative indices here for
+     * end-relative indexing) or an end-based index greater than 'end' itself.
+     */
+
+    tokenPtr = TokenAfter(listTokenPtr);
+    if (GetIndexFromToken(tokenPtr, &idx1) != TCL_OK) {
+	return TCL_ERROR;
+    }
+
+    tokenPtr = TokenAfter(tokenPtr);
+    if (GetIndexFromToken(tokenPtr, &idx2) != TCL_OK) {
+	return TCL_ERROR;
+    }
+
+    /*
+     * Issue instructions. It's not safe to skip doing the LIST_RANGE, as
+     * we've not proved that the 'list' argument is really a list. Not that it
+     * is worth trying to do that given current knowledge.
+     */
+
+    CompileWord(envPtr, listTokenPtr, interp, 1);
+    TclEmitInstInt4(		INST_LIST_RANGE_IMM, idx1,	envPtr);
+    TclEmitInt4(		idx2,				envPtr);
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclCompileLinsertCmd --
+ *
+ *	How to compile the "linsert" command. We only bother with the case
+ *	where the index is constant.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclCompileLinsertCmd(
+    Tcl_Interp *interp,		/* Tcl interpreter for context. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the
+				 * command. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds the resulting instructions. */
+{
+    Tcl_Token *tokenPtr, *listTokenPtr;
+    DefineLineInformation;	/* TIP #280 */
+    int idx, i;
+
+    if (parsePtr->numWords < 3) {
+	return TCL_ERROR;
+    }
+    listTokenPtr = TokenAfter(parsePtr->tokenPtr);
+
+    /*
+     * Parse the index. Will only compile if it is constant and not an
+     * _integer_ less than zero (since we reserve negative indices here for
+     * end-relative indexing) or an end-based index greater than 'end' itself.
+     */
+
+    tokenPtr = TokenAfter(listTokenPtr);
+    if (GetIndexFromToken(tokenPtr, &idx) != TCL_OK) {
+	return TCL_ERROR;
+    }
+
+    /*
+     * There are four main cases. If there are no values to insert, this is
+     * just a confirm-listiness check. If the index is '0', this is a prepend.
+     * If the index is 'end' (== INDEX_END), this is an append. Otherwise,
+     * this is a splice (== split, insert values as list, concat-3).
+     */
+
+    CompileWord(envPtr, listTokenPtr, interp, 1);
+    if (parsePtr->numWords == 3) {
+	TclEmitInstInt4(	INST_LIST_RANGE_IMM, 0,		envPtr);
+	TclEmitInt4(			INDEX_END,		envPtr);
+	return TCL_OK;
+    }
+
+    for (i=3 ; i<parsePtr->numWords ; i++) {
+	tokenPtr = TokenAfter(tokenPtr);
+	CompileWord(envPtr, tokenPtr, interp, i);
+    }
+    TclEmitInstInt4(		INST_LIST, i-3,			envPtr);
+
+    if (idx == 0 /*start*/) {
+	TclEmitInstInt4(	INST_REVERSE, 2,		envPtr);
+	TclEmitOpcode(		INST_LIST_CONCAT,		envPtr);
+    } else if (idx == INDEX_END /*end*/) {
+	TclEmitOpcode(		INST_LIST_CONCAT,		envPtr);
+    } else {
+	if (idx < 0) {
+	    idx++;
+	}
+	TclEmitInstInt4(	INST_OVER, 1,			envPtr);
+	TclEmitInstInt4(	INST_LIST_RANGE_IMM, 0,		envPtr);
+	TclEmitInt4(			idx-1,			envPtr);
+	TclEmitInstInt4(	INST_REVERSE, 3,		envPtr);
+	TclEmitInstInt4(	INST_LIST_RANGE_IMM, idx,	envPtr);
+	TclEmitInt4(			INDEX_END,		envPtr);
+	TclEmitOpcode(		INST_LIST_CONCAT,		envPtr);
+	TclEmitOpcode(		INST_LIST_CONCAT,		envPtr);
+    }
+
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclCompileLreplaceCmd --
+ *
+ *	How to compile the "lreplace" command. We only bother with the case
+ *	where the indices are constant.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclCompileLreplaceCmd(
+    Tcl_Interp *interp,		/* Tcl interpreter for context. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the
+				 * command. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds the resulting instructions. */
+{
+    Tcl_Token *tokenPtr, *listTokenPtr;
+    DefineLineInformation;	/* TIP #280 */
+    Tcl_Obj *tmpObj;
+    int idx1, idx2, i, offset;
+
+    if (parsePtr->numWords < 4) {
+	return TCL_ERROR;
+    }
+    listTokenPtr = TokenAfter(parsePtr->tokenPtr);
+
+    /*
+     * Parse the indices. Will only compile if both are constants and not an
+     * _integer_ less than zero (since we reserve negative indices here for
+     * end-relative indexing) or an end-based index greater than 'end' itself.
+     */
+
+    tokenPtr = TokenAfter(listTokenPtr);
+    if (GetIndexFromToken(tokenPtr, &idx1) != TCL_OK) {
+	return TCL_ERROR;
+    }
+
+    tokenPtr = TokenAfter(tokenPtr);
+    if (GetIndexFromToken(tokenPtr, &idx2) != TCL_OK) {
+	return TCL_ERROR;
+    }
+
+    /*
+     * Work out what this [lreplace] is actually doing.
+     */
+
+    tmpObj = NULL;
+    CompileWord(envPtr, listTokenPtr, interp, 1);
+    if (parsePtr->numWords == 4) {
+	if (idx1 == 0) {
+	    if (idx2 == INDEX_END) {
+		goto dropAll;
+	    }
+	    idx1 = idx2 + 1;
+	    idx2 = INDEX_END;
+	    goto dropEnd;
+	} else if (idx2 == INDEX_END) {
+	    idx2 = idx1 - 1;
+	    idx1 = 0;
+	    goto dropEnd;
+	} else {
+	    if (idx1 > 0) {
+		tmpObj = Tcl_NewIntObj(idx1);
+		Tcl_IncrRefCount(tmpObj);
+	    }
+	    goto dropRange;
+	}
+    }
+
+    tokenPtr = TokenAfter(tokenPtr);
+    for (i=4 ; i<parsePtr->numWords ; i++) {
+	CompileWord(envPtr, tokenPtr, interp, i);
+	tokenPtr = TokenAfter(tokenPtr);
+    }
+    TclEmitInstInt4(		INST_LIST, i - 4,		envPtr);
+    TclEmitInstInt4(		INST_REVERSE, 2,		envPtr);
+    if (idx1 == 0) {
+	if (idx2 == INDEX_END) {
+	    goto replaceAll;
+	}
+	idx1 = idx2 + 1;
+	idx2 = INDEX_END;
+	goto replaceHead;
+    } else if (idx2 == INDEX_END) {
+	idx2 = idx1 - 1;
+	idx1 = 0;
+	goto replaceTail;
+    } else {
+	if (idx1 > 0 && idx2 > 0 && idx2 < idx1) {
+	    idx2 = idx1 - 1;
+	} else if (idx1 < 0 && idx2 < 0 && idx2 < idx1) {
+	    idx2 = idx1 - 1;
+	}
+	if (idx1 > 0) {
+	    tmpObj = Tcl_NewIntObj(idx1);
+	    Tcl_IncrRefCount(tmpObj);
+	}
+	goto replaceRange;
+    }
+
+    /*
+     * Issue instructions to perform the operations relating to configurations
+     * that just drop. The only argument pushed on the stack is the list to
+     * operate on.
+     */
+
+  dropAll:
+    TclEmitOpcode(		INST_LIST_LENGTH,		envPtr);
+    TclEmitOpcode(		INST_POP,			envPtr);
+    PushStringLiteral(envPtr,	"");
+    goto done;
+
+  dropEnd:
+    TclEmitInstInt4(		INST_LIST_RANGE_IMM, idx1,	envPtr);
+    TclEmitInt4(			idx2,			envPtr);
+    goto done;
+
+  dropRange:
+    if (tmpObj != NULL) {
+	TclEmitOpcode(		INST_DUP,			envPtr);
+	TclEmitOpcode(		INST_LIST_LENGTH,		envPtr);
+	TclEmitPush(TclAddLiteralObj(envPtr, tmpObj, NULL),	envPtr);
+	TclEmitOpcode(		INST_GT,			envPtr);
+	offset = CurrentOffset(envPtr);
+	TclEmitInstInt1(	INST_JUMP_TRUE1, 0,		envPtr);
+	TclEmitPush(TclAddLiteralObj(envPtr, Tcl_ObjPrintf(
+		"list doesn't contain element %d", idx1), NULL), envPtr);
+	CompileReturnInternal(envPtr, INST_RETURN_IMM, TCL_ERROR, 0,
+		Tcl_ObjPrintf("-errorcode {TCL OPERATION LREPLACE BADIDX}"));
+	TclStoreInt1AtPtr(CurrentOffset(envPtr) - offset,
+		envPtr->codeStart + offset + 1);
+	TclAdjustStackDepth(-1, envPtr);
+    }
+    TclEmitOpcode(		INST_DUP,			envPtr);
+    TclEmitInstInt4(		INST_LIST_RANGE_IMM, 0,		envPtr);
+    TclEmitInt4(			idx1 - 1,		envPtr);
+    TclEmitInstInt4(		INST_REVERSE, 2,		envPtr);
+    TclEmitInstInt4(		INST_LIST_RANGE_IMM, idx2 + 1,	envPtr);
+    TclEmitInt4(			INDEX_END,		envPtr);
+    TclEmitOpcode(		INST_LIST_CONCAT,		envPtr);
+    goto done;
+
+    /*
+     * Issue instructions to perform the operations relating to configurations
+     * that do real replacement. All arguments are pushed and assembled into a
+     * pair: the list of values to replace with, and the list to do the
+     * surgery on.
+     */
+
+  replaceAll:
+    TclEmitOpcode(		INST_LIST_LENGTH,		envPtr);
+    TclEmitOpcode(		INST_POP,			envPtr);
+    goto done;
+
+  replaceHead:
+    TclEmitInstInt4(		INST_LIST_RANGE_IMM, idx1,	envPtr);
+    TclEmitInt4(			idx2,			envPtr);
+    TclEmitOpcode(		INST_LIST_CONCAT,		envPtr);
+    goto done;
+
+  replaceTail:
+    TclEmitInstInt4(		INST_LIST_RANGE_IMM, idx1,	envPtr);
+    TclEmitInt4(			idx2,			envPtr);
+    TclEmitInstInt4(		INST_REVERSE, 2,		envPtr);
+    TclEmitOpcode(		INST_LIST_CONCAT,		envPtr);
+    goto done;
+
+  replaceRange:
+    if (tmpObj != NULL) {
+	TclEmitOpcode(		INST_DUP,			envPtr);
+	TclEmitOpcode(		INST_LIST_LENGTH,		envPtr);
+	TclEmitPush(TclAddLiteralObj(envPtr, tmpObj, NULL),	envPtr);
+	TclEmitOpcode(		INST_GT,			envPtr);
+	offset = CurrentOffset(envPtr);
+	TclEmitInstInt1(	INST_JUMP_TRUE1, 0,		envPtr);
+	TclEmitPush(TclAddLiteralObj(envPtr, Tcl_ObjPrintf(
+		"list doesn't contain element %d", idx1), NULL), envPtr);
+	CompileReturnInternal(envPtr, INST_RETURN_IMM, TCL_ERROR, 0,
+		Tcl_ObjPrintf("-errorcode {TCL OPERATION LREPLACE BADIDX}"));
+	TclStoreInt1AtPtr(CurrentOffset(envPtr) - offset,
+		envPtr->codeStart + offset + 1);
+	TclAdjustStackDepth(-1, envPtr);
+    }
+    TclEmitOpcode(		INST_DUP,			envPtr);
+    TclEmitInstInt4(		INST_LIST_RANGE_IMM, 0,		envPtr);
+    TclEmitInt4(			idx1 - 1,		envPtr);
+    TclEmitInstInt4(		INST_REVERSE, 2,		envPtr);
+    TclEmitInstInt4(		INST_LIST_RANGE_IMM, idx2 + 1,	envPtr);
+    TclEmitInt4(			INDEX_END,		envPtr);
+    TclEmitInstInt4(		INST_REVERSE, 3,		envPtr);
+    TclEmitOpcode(		INST_LIST_CONCAT,		envPtr);
+    TclEmitInstInt4(		INST_REVERSE, 2,		envPtr);
+    TclEmitOpcode(		INST_LIST_CONCAT,		envPtr);
+    goto done;
+
+    /*
+     * Clean up the allocated memory.
+     */
+
+  done:
+    if (tmpObj != NULL) {
+	Tcl_DecrRefCount(tmpObj);
+    }
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclCompileLsetCmd --
+ *
+ *	Procedure called to compile the "lset" command.
+ *
+ * Results:
+ *	Returns TCL_OK for a successful compile. Returns TCL_ERROR to defer
+ *	evaluation to runtime.
+ *
+ * Side effects:
+ *	Instructions are added to envPtr to execute the "lset" command at
+ *	runtime.
+ *
+ * The general template for execution of the "lset" command is:
+ *	(1) Instructions to push the variable name, unless the variable is
+ *	    local to the stack frame.
+ *	(2) If the variable is an array element, instructions to push the
+ *	    array element name.
+ *	(3) Instructions to push each of zero or more "index" arguments to the
+ *	    stack, followed with the "newValue" element.
+ *	(4) Instructions to duplicate the variable name and/or array element
+ *	    name onto the top of the stack, if either was pushed at steps (1)
+ *	    and (2).
+ *	(5) The appropriate INST_LOAD_* instruction to place the original
+ *	    value of the list variable at top of stack.
+ *	(6) At this point, the stack contains:
+ *		varName? arrayElementName? index1 index2 ... newValue oldList
+ *	    The compiler emits one of INST_LSET_FLAT or INST_LSET_LIST
+ *	    according as whether there is exactly one index element (LIST) or
+ *	    either zero or else two or more (FLAT). This instruction removes
+ *	    everything from the stack except for the two names and pushes the
+ *	    new value of the variable.
+ *	(7) Finally, INST_STORE_* stores the new value in the variable and
+ *	    cleans up the stack.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclCompileLsetCmd(
+    Tcl_Interp *interp,		/* Tcl interpreter for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the
+				 * command. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds the resulting instructions. */
+{
+    int tempDepth;		/* Depth used for emitting one part of the
+				 * code burst. */
+    Tcl_Token *varTokenPtr;	/* Pointer to the Tcl_Token representing the
+				 * parse of the variable name. */
+    int localIndex;		/* Index of var in local var table. */
+    int isScalar;		/* Flag == 1 if scalar, 0 if array. */
+    int i;
+    DefineLineInformation;	/* TIP #280 */
+
+    /*
+     * Check argument count.
+     */
+
+    /* TODO: Consider support for compiling expanded args. */
+    if (parsePtr->numWords < 3) {
+	/*
+	 * Fail at run time, not in compilation.
+	 */
+
+	return TCL_ERROR;
+    }
+
+    /*
+     * Decide if we can use a frame slot for the var/array name or if we need
+     * to emit code to compute and push the name at runtime. We use a frame
+     * slot (entry in the array of local vars) if we are compiling a procedure
+     * body and if the name is simple text that does not include namespace
+     * qualifiers.
+     */
+
+    varTokenPtr = TokenAfter(parsePtr->tokenPtr);
+    PushVarNameWord(interp, varTokenPtr, envPtr, 0,
+	    &localIndex, &isScalar, 1);
+
+    /*
+     * Push the "index" args and the new element value.
+     */
+
+    for (i=2 ; i<parsePtr->numWords ; ++i) {
+	varTokenPtr = TokenAfter(varTokenPtr);
+	CompileWord(envPtr, varTokenPtr, interp, i);
+    }
+
+    /*
+     * Duplicate the variable name if it's been pushed.
+     */
+
+    if (localIndex < 0) {
+	if (isScalar) {
+	    tempDepth = parsePtr->numWords - 2;
+	} else {
+	    tempDepth = parsePtr->numWords - 1;
+	}
+	TclEmitInstInt4(	INST_OVER, tempDepth,		envPtr);
+    }
+
+    /*
+     * Duplicate an array index if one's been pushed.
+     */
+
+    if (!isScalar) {
+	if (localIndex < 0) {
+	    tempDepth = parsePtr->numWords - 1;
+	} else {
+	    tempDepth = parsePtr->numWords - 2;
+	}
+	TclEmitInstInt4(	INST_OVER, tempDepth,		envPtr);
+    }
+
+    /*
+     * Emit code to load the variable's value.
+     */
+
+    if (isScalar) {
+	if (localIndex < 0) {
+	    TclEmitOpcode(	INST_LOAD_STK,			envPtr);
+	} else {
+	    Emit14Inst(		INST_LOAD_SCALAR, localIndex,	envPtr);
+	}
+    } else {
+	if (localIndex < 0) {
+	    TclEmitOpcode(	INST_LOAD_ARRAY_STK,		envPtr);
+	} else {
+	    Emit14Inst(		INST_LOAD_ARRAY, localIndex,	envPtr);
+	}
+    }
+
+    /*
+     * Emit the correct variety of 'lset' instruction.
+     */
+
+    if (parsePtr->numWords == 4) {
+	TclEmitOpcode(		INST_LSET_LIST,			envPtr);
+    } else {
+	TclEmitInstInt4(	INST_LSET_FLAT, parsePtr->numWords-1, envPtr);
+    }
+
+    /*
+     * Emit code to put the value back in the variable.
+     */
+
+    if (isScalar) {
+	if (localIndex < 0) {
+	    TclEmitOpcode(	INST_STORE_STK,			envPtr);
+	} else {
+	    Emit14Inst(		INST_STORE_SCALAR, localIndex,	envPtr);
+	}
+    } else {
+	if (localIndex < 0) {
+	    TclEmitOpcode(	INST_STORE_ARRAY_STK,		envPtr);
+	} else {
+	    Emit14Inst(		INST_STORE_ARRAY, localIndex,	envPtr);
+	}
+    }
+
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclCompileNamespace*Cmd --
+ *
+ *	Procedures called to compile the "namespace" command; currently, only
+ *	the subcommands "namespace current" and "namespace upvar" are compiled
+ *	to bytecodes, and the latter only inside a procedure(-like) context.
+ *
+ * Results:
+ *	Returns TCL_OK for a successful compile. Returns TCL_ERROR to defer
+ *	evaluation to runtime.
+ *
+ * Side effects:
+ *	Instructions are added to envPtr to execute the "namespace upvar"
+ *	command at runtime.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclCompileNamespaceCurrentCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    /*
+     * Only compile [namespace current] without arguments.
+     */
+
+    if (parsePtr->numWords != 1) {
+	return TCL_ERROR;
+    }
+
+    /*
+     * Not much to do; we compile to a single instruction...
+     */
+
+    TclEmitOpcode(		INST_NS_CURRENT,		envPtr);
+    return TCL_OK;
+}
+
+int
+TclCompileNamespaceCodeCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    Tcl_Token *tokenPtr;
+    DefineLineInformation;	/* TIP #280 */
+
+    if (parsePtr->numWords != 2) {
+	return TCL_ERROR;
+    }
+    tokenPtr = TokenAfter(parsePtr->tokenPtr);
+
+    /*
+     * The specification of [namespace code] is rather shocking, in that it is
+     * supposed to check if the argument is itself the result of [namespace
+     * code] and not apply itself in that case. Which is excessively cautious,
+     * but what the test suite checks for.
+     */
+
+    if (tokenPtr->type != TCL_TOKEN_SIMPLE_WORD || (tokenPtr[1].size > 20
+	    && strncmp(tokenPtr[1].start, "::namespace inscope ", 20) == 0)) {
+	/*
+	 * Technically, we could just pass a literal '::namespace inscope '
+	 * term through, but that's something which really shouldn't be
+	 * occurring as something that the user writes so we'll just punt it.
+	 */
+
+	return TCL_ERROR;
+    }
+
+    /*
+     * Now we can compile using the same strategy as [namespace code]'s normal
+     * implementation does internally. Note that we can't bind the namespace
+     * name directly here, because TclOO plays complex games with namespaces;
+     * the value needs to be determined at runtime for safety.
+     */
+
+    PushStringLiteral(envPtr,		"::namespace");
+    PushStringLiteral(envPtr,		"inscope");
+    TclEmitOpcode(		INST_NS_CURRENT,	envPtr);
+    CompileWord(envPtr,		tokenPtr,		interp, 1);
+    TclEmitInstInt4(		INST_LIST, 4,		envPtr);
+    return TCL_OK;
+}
+
+int
+TclCompileNamespaceOriginCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    Tcl_Token *tokenPtr;
+    DefineLineInformation;	/* TIP #280 */
+
+    if (parsePtr->numWords != 2) {
+	return TCL_ERROR;
+    }
+    tokenPtr = TokenAfter(parsePtr->tokenPtr);
+
+    CompileWord(envPtr,	tokenPtr,			interp, 1);
+    TclEmitOpcode(	INST_ORIGIN_COMMAND,		envPtr);
+    return TCL_OK;
+}
+
+int
+TclCompileNamespaceQualifiersCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    Tcl_Token *tokenPtr = TokenAfter(parsePtr->tokenPtr);
+    DefineLineInformation;	/* TIP #280 */
+    int off;
+
+    if (parsePtr->numWords != 2) {
+	return TCL_ERROR;
+    }
+
+    CompileWord(envPtr, tokenPtr, interp, 1);
+    PushStringLiteral(envPtr, "0");
+    PushStringLiteral(envPtr, "::");
+    TclEmitInstInt4(	INST_OVER, 2,			envPtr);
+    TclEmitOpcode(	INST_STR_FIND_LAST,		envPtr);
+    off = CurrentOffset(envPtr);
+    PushStringLiteral(envPtr, "1");
+    TclEmitOpcode(	INST_SUB,			envPtr);
+    TclEmitInstInt4(	INST_OVER, 2,			envPtr);
+    TclEmitInstInt4(	INST_OVER, 1,			envPtr);
+    TclEmitOpcode(	INST_STR_INDEX,			envPtr);
+    PushStringLiteral(envPtr, ":");
+    TclEmitOpcode(	INST_STR_EQ,			envPtr);
+    off = off - CurrentOffset(envPtr);
+    TclEmitInstInt1(	INST_JUMP_TRUE1, off,		envPtr);
+    TclEmitOpcode(	INST_STR_RANGE,			envPtr);
+    return TCL_OK;
+}
+
+int
+TclCompileNamespaceTailCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    Tcl_Token *tokenPtr = TokenAfter(parsePtr->tokenPtr);
+    DefineLineInformation;	/* TIP #280 */
+    JumpFixup jumpFixup;
+
+    if (parsePtr->numWords != 2) {
+	return TCL_ERROR;
+    }
+
+    /*
+     * Take care; only add 2 to found index if the string was actually found.
+     */
+
+    CompileWord(envPtr, tokenPtr, interp, 1);
+    PushStringLiteral(envPtr, "::");
+    TclEmitInstInt4(	INST_OVER, 1,			envPtr);
+    TclEmitOpcode(	INST_STR_FIND_LAST,		envPtr);
+    TclEmitOpcode(	INST_DUP,			envPtr);
+    PushStringLiteral(envPtr, "0");
+    TclEmitOpcode(	INST_GE,			envPtr);
+    TclEmitForwardJump(envPtr, TCL_FALSE_JUMP, &jumpFixup);
+    PushStringLiteral(envPtr, "2");
+    TclEmitOpcode(	INST_ADD,			envPtr);
+    TclFixupForwardJumpToHere(envPtr, &jumpFixup, 127);
+    PushStringLiteral(envPtr, "end");
+    TclEmitOpcode(	INST_STR_RANGE,			envPtr);
+    return TCL_OK;
+}
+
+int
+TclCompileNamespaceUpvarCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    Tcl_Token *tokenPtr, *otherTokenPtr, *localTokenPtr;
+    int isScalar, localIndex, numWords, i;
+    DefineLineInformation;	/* TIP #280 */
+
+    if (envPtr->procPtr == NULL) {
+	return TCL_ERROR;
+    }
+
+    /*
+     * Only compile [namespace upvar ...]: needs an even number of args, >=4
+     */
+
+    numWords = parsePtr->numWords;
+    if ((numWords % 2) || (numWords < 4)) {
+	return TCL_ERROR;
+    }
+
+    /*
+     * Push the namespace
+     */
+
+    tokenPtr = TokenAfter(parsePtr->tokenPtr);
+    CompileWord(envPtr, tokenPtr, interp, 1);
+
+    /*
+     * Loop over the (otherVar, thisVar) pairs. If any of the thisVar is not a
+     * local variable, return an error so that the non-compiled command will
+     * be called at runtime.
+     */
+
+    localTokenPtr = tokenPtr;
+    for (i=2; i<numWords; i+=2) {
+	otherTokenPtr = TokenAfter(localTokenPtr);
+	localTokenPtr = TokenAfter(otherTokenPtr);
+
+	CompileWord(envPtr, otherTokenPtr, interp, i);
+	PushVarNameWord(interp, localTokenPtr, envPtr, 0,
+		&localIndex, &isScalar, i+1);
+
+	if ((localIndex < 0) || !isScalar) {
+	    return TCL_ERROR;
+	}
+	TclEmitInstInt4(	INST_NSUPVAR, localIndex,	envPtr);
+    }
+
+    /*
+     * Pop the namespace, and set the result to empty
+     */
+
+    TclEmitOpcode(		INST_POP,			envPtr);
+    PushStringLiteral(envPtr, "");
+    return TCL_OK;
+}
+
+int
+TclCompileNamespaceWhichCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    DefineLineInformation;	/* TIP #280 */
+    Tcl_Token *tokenPtr, *opt;
+    int idx;
+
+    if (parsePtr->numWords < 2 || parsePtr->numWords > 3) {
+	return TCL_ERROR;
+    }
+    tokenPtr = TokenAfter(parsePtr->tokenPtr);
+    idx = 1;
+
+    /*
+     * If there's an option, check that it's "-command". We don't handle
+     * "-variable" (currently) and anything else is an error.
+     */
+
+    if (parsePtr->numWords == 3) {
+	if (tokenPtr->type != TCL_TOKEN_SIMPLE_WORD) {
+	    return TCL_ERROR;
+	}
+	opt = tokenPtr + 1;
+	if (opt->size < 2 || opt->size > 8
+		|| strncmp(opt->start, "-command", opt->size) != 0) {
+	    return TCL_ERROR;
+	}
+	tokenPtr = TokenAfter(tokenPtr);
+	idx++;
+    }
+
+    /*
+     * Issue the bytecode.
+     */
+
+    CompileWord(envPtr,		tokenPtr,		interp, idx);
+    TclEmitOpcode(		INST_RESOLVE_COMMAND,	envPtr);
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclCompileRegexpCmd --
+ *
+ *	Procedure called to compile the "regexp" command.
+ *
+ * Results:
+ *	Returns TCL_OK for a successful compile. Returns TCL_ERROR to defer
+ *	evaluation to runtime.
+ *
+ * Side effects:
+ *	Instructions are added to envPtr to execute the "regexp" command at
+ *	runtime.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclCompileRegexpCmd(
+    Tcl_Interp *interp,		/* Tcl interpreter for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the
+				 * command. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds the resulting instructions. */
+{
+    Tcl_Token *varTokenPtr;	/* Pointer to the Tcl_Token representing the
+				 * parse of the RE or string. */
+    int i, len, nocase, exact, sawLast, simple;
+    const char *str;
+    DefineLineInformation;	/* TIP #280 */
+
+    /*
+     * We are only interested in compiling simple regexp cases. Currently
+     * supported compile cases are:
+     *   regexp ?-nocase? ?--? staticString $var
+     *   regexp ?-nocase? ?--? {^staticString$} $var
+     */
+
+    if (parsePtr->numWords < 3) {
+	return TCL_ERROR;
+    }
+
+    simple = 0;
+    nocase = 0;
+    sawLast = 0;
+    varTokenPtr = parsePtr->tokenPtr;
+
+    /*
+     * We only look for -nocase and -- as options. Everything else gets pushed
+     * to runtime execution. This is different than regexp's runtime option
+     * handling, but satisfies our stricter needs.
+     */
+
+    for (i = 1; i < parsePtr->numWords - 2; i++) {
+	varTokenPtr = TokenAfter(varTokenPtr);
+	if (varTokenPtr->type != TCL_TOKEN_SIMPLE_WORD) {
+	    /*
+	     * Not a simple string, so punt to runtime.
+	     */
+
+	    return TCL_ERROR;
+	}
+	str = varTokenPtr[1].start;
+	len = varTokenPtr[1].size;
+	if ((len == 2) && (str[0] == '-') && (str[1] == '-')) {
+	    sawLast++;
+	    i++;
+	    break;
+	} else if ((len > 1) && (strncmp(str,"-nocase",(unsigned)len) == 0)) {
+	    nocase = 1;
+	} else {
+	    /*
+	     * Not an option we recognize.
+	     */
+
+	    return TCL_ERROR;
+	}
+    }
+
+    if ((parsePtr->numWords - i) != 2) {
+	/*
+	 * We don't support capturing to variables.
+	 */
+
+	return TCL_ERROR;
+    }
+
+    /*
+     * Get the regexp string. If it is not a simple string or can't be
+     * converted to a glob pattern, push the word for the INST_REGEXP.
+     * Keep changes here in sync with TclCompileSwitchCmd Switch_Regexp.
+     */
+
+    varTokenPtr = TokenAfter(varTokenPtr);
+
+    if (varTokenPtr->type == TCL_TOKEN_SIMPLE_WORD) {
+	Tcl_DString ds;
+
+	str = varTokenPtr[1].start;
+	len = varTokenPtr[1].size;
+
+	/*
+	 * If it has a '-', it could be an incorrectly formed regexp command.
+	 */
+
+	if ((*str == '-') && !sawLast) {
+	    return TCL_ERROR;
+	}
+
+	if (len == 0) {
+	    /*
+	     * The semantics of regexp are always match on re == "".
+	     */
+
+	    PushStringLiteral(envPtr, "1");
+	    return TCL_OK;
+	}
+
+	/*
+	 * Attempt to convert pattern to glob.  If successful, push the
+	 * converted pattern as a literal.
+	 */
+
+	if (TclReToGlob(NULL, varTokenPtr[1].start, len, &ds, &exact)
+		== TCL_OK) {
+	    simple = 1;
+	    PushLiteral(envPtr, Tcl_DStringValue(&ds),Tcl_DStringLength(&ds));
+	    Tcl_DStringFree(&ds);
+	}
+    }
+
+    if (!simple) {
+	CompileWord(envPtr, varTokenPtr, interp, parsePtr->numWords-2);
+    }
+
+    /*
+     * Push the string arg.
+     */
+
+    varTokenPtr = TokenAfter(varTokenPtr);
+    CompileWord(envPtr, varTokenPtr, interp, parsePtr->numWords-1);
+
+    if (simple) {
+	if (exact && !nocase) {
+	    TclEmitOpcode(	INST_STR_EQ,			envPtr);
+	} else {
+	    TclEmitInstInt1(	INST_STR_MATCH, nocase,		envPtr);
+	}
+    } else {
+	/*
+	 * Pass correct RE compile flags.  We use only Int1 (8-bit), but
+	 * that handles all the flags we want to pass.
+	 * Don't use TCL_REG_NOSUB as we may have backrefs.
+	 */
+
+	int cflags = TCL_REG_ADVANCED | (nocase ? TCL_REG_NOCASE : 0);
+
+	TclEmitInstInt1(	INST_REGEXP, cflags,		envPtr);
+    }
+
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclCompileRegsubCmd --
+ *
+ *	Procedure called to compile the "regsub" command.
+ *
+ * Results:
+ *	Returns TCL_OK for a successful compile. Returns TCL_ERROR to defer
+ *	evaluation to runtime.
+ *
+ * Side effects:
+ *	Instructions are added to envPtr to execute the "regsub" command at
+ *	runtime.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclCompileRegsubCmd(
+    Tcl_Interp *interp,		/* Tcl interpreter for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the
+				 * command. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds the resulting instructions. */
+{
+    /*
+     * We only compile the case with [regsub -all] where the pattern is both
+     * known at compile time and simple (i.e., no RE metacharacters). That is,
+     * the pattern must be translatable into a glob like "*foo*" with no other
+     * glob metacharacters inside it; there must be some "foo" in there too.
+     * The substitution string must also be known at compile time and free of
+     * metacharacters ("\digit" and "&"). Finally, there must not be a
+     * variable mentioned in the [regsub] to write the result back to (because
+     * we can't get the count of substitutions that would be the result in
+     * that case). The key is that these are the conditions under which a
+     * [string map] could be used instead, in particular a [string map] of the
+     * form we can compile to bytecode.
+     *
+     * In short, we look for:
+     *
+     *   regsub -all [--] simpleRE string simpleReplacement
+     *
+     * The only optional part is the "--", and no other options are handled.
+     */
+
+    DefineLineInformation;	/* TIP #280 */
+    Tcl_Token *tokenPtr, *stringTokenPtr;
+    Tcl_Obj *patternObj = NULL, *replacementObj = NULL;
+    Tcl_DString pattern;
+    const char *bytes;
+    int len, exact, result = TCL_ERROR;
+
+    if (parsePtr->numWords < 5 || parsePtr->numWords > 6) {
+	return TCL_ERROR;
+    }
+
+    /*
+     * Parse the "-all", which must be the first argument (other options not
+     * supported, non-"-all" substitution we can't compile).
+     */
+
+    tokenPtr = TokenAfter(parsePtr->tokenPtr);
+    if (tokenPtr->type != TCL_TOKEN_SIMPLE_WORD || tokenPtr[1].size != 4
+	    || strncmp(tokenPtr[1].start, "-all", 4)) {
+	return TCL_ERROR;
+    }
+
+    /*
+     * Get the pattern into patternObj, checking for "--" in the process.
+     */
+
+    Tcl_DStringInit(&pattern);
+    tokenPtr = TokenAfter(tokenPtr);
+    patternObj = Tcl_NewObj();
+    if (!TclWordKnownAtCompileTime(tokenPtr, patternObj)) {
+	goto done;
+    }
+    if (Tcl_GetString(patternObj)[0] == '-') {
+	if (strcmp(Tcl_GetString(patternObj), "--") != 0
+		|| parsePtr->numWords == 5) {
+	    goto done;
+	}
+	tokenPtr = TokenAfter(tokenPtr);
+	Tcl_DecrRefCount(patternObj);
+	patternObj = Tcl_NewObj();
+	if (!TclWordKnownAtCompileTime(tokenPtr, patternObj)) {
+	    goto done;
+	}
+    } else if (parsePtr->numWords == 6) {
+	goto done;
+    }
+
+    /*
+     * Identify the code which produces the string to apply the substitution
+     * to (stringTokenPtr), and the replacement string (into replacementObj).
+     */
+
+    stringTokenPtr = TokenAfter(tokenPtr);
+    tokenPtr = TokenAfter(stringTokenPtr);
+    replacementObj = Tcl_NewObj();
+    if (!TclWordKnownAtCompileTime(tokenPtr, replacementObj)) {
+	goto done;
+    }
+
+    /*
+     * Next, higher-level checks. Is the RE a very simple glob? Is the
+     * replacement "simple"?
+     */
+
+    bytes = Tcl_GetStringFromObj(patternObj, &len);
+    if (TclReToGlob(NULL, bytes, len, &pattern, &exact) != TCL_OK || exact) {
+	goto done;
+    }
+    bytes = Tcl_DStringValue(&pattern);
+    if (*bytes++ != '*') {
+	goto done;
+    }
+    while (1) {
+	switch (*bytes) {
+	case '*':
+	    if (bytes[1] == '\0') {
+		/*
+		 * OK, we've proved there are no metacharacters except for the
+		 * '*' at each end.
+		 */
+
+		len = Tcl_DStringLength(&pattern) - 2;
+		if (len > 0) {
+		    goto isSimpleGlob;
+		}
+
+		/*
+		 * The pattern is "**"! I believe that should be impossible,
+		 * but we definitely can't handle that at all.
+		 */
+	    }
+	case '\0': case '?': case '[': case '\\':
+	    goto done;
+	}
+	bytes++;
+    }
+  isSimpleGlob:
+    for (bytes = Tcl_GetString(replacementObj); *bytes; bytes++) {
+	switch (*bytes) {
+	case '\\': case '&':
+	    goto done;
+	}
+    }
+
+    /*
+     * Proved the simplicity constraints! Time to issue the code.
+     */
+
+    result = TCL_OK;
+    bytes = Tcl_DStringValue(&pattern) + 1;
+    PushLiteral(envPtr,	bytes, len);
+    bytes = Tcl_GetStringFromObj(replacementObj, &len);
+    PushLiteral(envPtr,	bytes, len);
+    CompileWord(envPtr,	stringTokenPtr, interp, parsePtr->numWords-2);
+    TclEmitOpcode(	INST_STR_MAP,	envPtr);
+
+  done:
+    Tcl_DStringFree(&pattern);
+    if (patternObj) {
+	Tcl_DecrRefCount(patternObj);
+    }
+    if (replacementObj) {
+	Tcl_DecrRefCount(replacementObj);
+    }
+    return result;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclCompileReturnCmd --
+ *
+ *	Procedure called to compile the "return" command.
+ *
+ * Results:
+ *	Returns TCL_OK for a successful compile. Returns TCL_ERROR to defer
+ *	evaluation to runtime.
+ *
+ * Side effects:
+ *	Instructions are added to envPtr to execute the "return" command at
+ *	runtime.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclCompileReturnCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    /*
+     * General syntax: [return ?-option value ...? ?result?]
+     * An even number of words means an explicit result argument is present.
+     */
+    int level, code, objc, size, status = TCL_OK;
+    int numWords = parsePtr->numWords;
+    int explicitResult = (0 == (numWords % 2));
+    int numOptionWords = numWords - 1 - explicitResult;
+    Tcl_Obj *returnOpts, **objv;
+    Tcl_Token *wordTokenPtr = TokenAfter(parsePtr->tokenPtr);
+    DefineLineInformation;	/* TIP #280 */
+
+    /*
+     * Check for special case which can always be compiled:
+     *	    return -options <opts> <msg>
+     * Unlike the normal [return] compilation, this version does everything at
+     * runtime so it can handle arbitrary words and not just literals. Note
+     * that if INST_RETURN_STK wasn't already needed for something else
+     * ('finally' clause processing) this piece of code would not be present.
+     */
+
+    if ((numWords == 4) && (wordTokenPtr->type == TCL_TOKEN_SIMPLE_WORD)
+	    && (wordTokenPtr[1].size == 8)
+	    && (strncmp(wordTokenPtr[1].start, "-options", 8) == 0)) {
+	Tcl_Token *optsTokenPtr = TokenAfter(wordTokenPtr);
+	Tcl_Token *msgTokenPtr = TokenAfter(optsTokenPtr);
+
+	CompileWord(envPtr, optsTokenPtr, interp, 2);
+	CompileWord(envPtr, msgTokenPtr,  interp, 3);
+	TclEmitInvoke(envPtr, INST_RETURN_STK);
+	return TCL_OK;
+    }
+
+    /*
+     * Allocate some working space.
+     */
+
+    objv = TclStackAlloc(interp, numOptionWords * sizeof(Tcl_Obj *));
+
+    /*
+     * Scan through the return options. If any are unknown at compile time,
+     * there is no value in bytecompiling. Save the option values known in an
+     * objv array for merging into a return options dictionary.
+     *
+     * TODO: There is potential for improvement if all option keys are known
+     * at compile time and all option values relating to '-code' and '-level'
+     * are known at compile time.
+     */
+
+    for (objc = 0; objc < numOptionWords; objc++) {
+	objv[objc] = Tcl_NewObj();
+	Tcl_IncrRefCount(objv[objc]);
+	if (!TclWordKnownAtCompileTime(wordTokenPtr, objv[objc])) {
+	    /*
+	     * Non-literal, so punt to run-time assembly of the dictionary.
+	     */
+
+	    for (; objc>=0 ; objc--) {
+		TclDecrRefCount(objv[objc]);
+	    }
+	    TclStackFree(interp, objv);
+	    goto issueRuntimeReturn;
+	}
+	wordTokenPtr = TokenAfter(wordTokenPtr);
+    }
+    status = TclMergeReturnOptions(interp, objc, objv,
+	    &returnOpts, &code, &level);
+    while (--objc >= 0) {
+	TclDecrRefCount(objv[objc]);
+    }
+    TclStackFree(interp, objv);
+    if (TCL_ERROR == status) {
+	/*
+	 * Something was bogus in the return options. Clear the error message,
+	 * and report back to the compiler that this must be interpreted at
+	 * runtime.
+	 */
+
+	Tcl_ResetResult(interp);
+	return TCL_ERROR;
+    }
+
+    /*
+     * All options are known at compile time, so we're going to bytecompile.
+     * Emit instructions to push the result on the stack.
+     */
+
+    if (explicitResult) {
+	 CompileWord(envPtr, wordTokenPtr, interp, numWords-1);
+    } else {
+	/*
+	 * No explict result argument, so default result is empty string.
+	 */
+
+	PushStringLiteral(envPtr, "");
+    }
+
+    /*
+     * Check for optimization: When [return] is in a proc, and there's no
+     * enclosing [catch], and there are no return options, then the INST_DONE
+     * instruction is equivalent, and may be more efficient.
+     */
+
+    if (numOptionWords == 0 && envPtr->procPtr != NULL) {
+	/*
+	 * We have default return options and we're in a proc ...
+	 */
+
+	int index = envPtr->exceptArrayNext - 1;
+	int enclosingCatch = 0;
+
+	while (index >= 0) {
+	    ExceptionRange range = envPtr->exceptArrayPtr[index];
+
+	    if ((range.type == CATCH_EXCEPTION_RANGE)
+		    && (range.catchOffset == -1)) {
+		enclosingCatch = 1;
+		break;
+	    }
+	    index--;
+	}
+	if (!enclosingCatch) {
+	    /*
+	     * ... and there is no enclosing catch. Issue the maximally
+	     * efficient exit instruction.
+	     */
+
+	    Tcl_DecrRefCount(returnOpts);
+	    TclEmitOpcode(INST_DONE, envPtr);
+	    TclAdjustStackDepth(1, envPtr);
+	    return TCL_OK;
+	}
+    }
+
+    /* Optimize [return -level 0 $x]. */
+    Tcl_DictObjSize(NULL, returnOpts, &size);
+    if (size == 0 && level == 0 && code == TCL_OK) {
+	Tcl_DecrRefCount(returnOpts);
+	return TCL_OK;
+    }
+
+    /*
+     * Could not use the optimization, so we push the return options dict, and
+     * emit the INST_RETURN_IMM instruction with code and level as operands.
+     */
+
+    CompileReturnInternal(envPtr, INST_RETURN_IMM, code, level, returnOpts);
+    return TCL_OK;
+
+  issueRuntimeReturn:
+    /*
+     * Assemble the option dictionary (as a list as that's good enough).
+     */
+
+    wordTokenPtr = TokenAfter(parsePtr->tokenPtr);
+    for (objc=1 ; objc<=numOptionWords ; objc++) {
+	CompileWord(envPtr, wordTokenPtr, interp, objc);
+	wordTokenPtr = TokenAfter(wordTokenPtr);
+    }
+    TclEmitInstInt4(INST_LIST, numOptionWords, envPtr);
+
+    /*
+     * Push the result.
+     */
+
+    if (explicitResult) {
+	CompileWord(envPtr, wordTokenPtr, interp, numWords-1);
+    } else {
+	PushStringLiteral(envPtr, "");
+    }
+
+    /*
+     * Issue the RETURN itself.
+     */
+
+    TclEmitInvoke(envPtr, INST_RETURN_STK);
+    return TCL_OK;
+}
+
+static void
+CompileReturnInternal(
+    CompileEnv *envPtr,
+    unsigned char op,
+    int code,
+    int level,
+    Tcl_Obj *returnOpts)
+{
+    if (level == 0 && (code == TCL_BREAK || code == TCL_CONTINUE)) {
+	ExceptionRange *rangePtr;
+	ExceptionAux *exceptAux;
+
+	rangePtr = TclGetInnermostExceptionRange(envPtr, code, &exceptAux);
+	if (rangePtr && rangePtr->type == LOOP_EXCEPTION_RANGE) {
+	    TclCleanupStackForBreakContinue(envPtr, exceptAux);
+	    if (code == TCL_BREAK) {
+		TclAddLoopBreakFixup(envPtr, exceptAux);
+	    } else {
+		TclAddLoopContinueFixup(envPtr, exceptAux);
+	    }
+	    Tcl_DecrRefCount(returnOpts);
+	    return;
+	}
+    }
+
+    TclEmitPush(TclAddLiteralObj(envPtr, returnOpts, NULL), envPtr);
+    TclEmitInstInt4(op, code, envPtr);
+    TclEmitInt4(level, envPtr);
+}
+
+void
+TclCompileSyntaxError(
+    Tcl_Interp *interp,
+    CompileEnv *envPtr)
+{
+    Tcl_Obj *msg = Tcl_GetObjResult(interp);
+    int numBytes;
+    const char *bytes = TclGetStringFromObj(msg, &numBytes);
+
+    TclErrorStackResetIf(interp, bytes, numBytes);
+    TclEmitPush(TclRegisterNewLiteral(envPtr, bytes, numBytes), envPtr);
+    CompileReturnInternal(envPtr, INST_SYNTAX, TCL_ERROR, 0,
+	    TclNoErrorStack(interp, Tcl_GetReturnOptions(interp, TCL_ERROR)));
+    Tcl_ResetResult(interp);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclCompileUpvarCmd --
+ *
+ *	Procedure called to compile the "upvar" command.
+ *
+ * Results:
+ *	Returns TCL_OK for a successful compile. Returns TCL_ERROR to defer
+ *	evaluation to runtime.
+ *
+ * Side effects:
+ *	Instructions are added to envPtr to execute the "upvar" command at
+ *	runtime.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclCompileUpvarCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    Tcl_Token *tokenPtr, *otherTokenPtr, *localTokenPtr;
+    int isScalar, localIndex, numWords, i;
+    DefineLineInformation;	/* TIP #280 */
+    Tcl_Obj *objPtr;
+
+    if (envPtr->procPtr == NULL) {
+	return TCL_ERROR;
+    }
+
+    numWords = parsePtr->numWords;
+    if (numWords < 3) {
+	return TCL_ERROR;
+    }
+
+    /*
+     * Push the frame index if it is known at compile time
+     */
+
+    objPtr = Tcl_NewObj();
+    tokenPtr = TokenAfter(parsePtr->tokenPtr);
+    if (TclWordKnownAtCompileTime(tokenPtr, objPtr)) {
+	CallFrame *framePtr;
+	const Tcl_ObjType *newTypePtr, *typePtr = objPtr->typePtr;
+
+	/*
+	 * Attempt to convert to a level reference. Note that TclObjGetFrame
+	 * only changes the obj type when a conversion was successful.
+	 */
+
+	TclObjGetFrame(interp, objPtr, &framePtr);
+	newTypePtr = objPtr->typePtr;
+	Tcl_DecrRefCount(objPtr);
+
+	if (newTypePtr != typePtr) {
+	    if (numWords%2) {
+		return TCL_ERROR;
+	    }
+	    /* TODO: Push the known value instead? */
+	    CompileWord(envPtr, tokenPtr, interp, 1);
+	    otherTokenPtr = TokenAfter(tokenPtr);
+	    i = 2;
+	} else {
+	    if (!(numWords%2)) {
+		return TCL_ERROR;
+	    }
+	    PushStringLiteral(envPtr, "1");
+	    otherTokenPtr = tokenPtr;
+	    i = 1;
+	}
+    } else {
+	Tcl_DecrRefCount(objPtr);
+	return TCL_ERROR;
+    }
+
+    /*
+     * Loop over the (otherVar, thisVar) pairs. If any of the thisVar is not a
+     * local variable, return an error so that the non-compiled command will
+     * be called at runtime.
+     */
+
+    for (; i<numWords; i+=2, otherTokenPtr = TokenAfter(localTokenPtr)) {
+	localTokenPtr = TokenAfter(otherTokenPtr);
+
+	CompileWord(envPtr, otherTokenPtr, interp, i);
+	PushVarNameWord(interp, localTokenPtr, envPtr, 0,
+		&localIndex, &isScalar, i+1);
+
+	if ((localIndex < 0) || !isScalar) {
+	    return TCL_ERROR;
+	}
+	TclEmitInstInt4(	INST_UPVAR, localIndex,		envPtr);
+    }
+
+    /*
+     * Pop the frame index, and set the result to empty
+     */
+
+    TclEmitOpcode(		INST_POP,			envPtr);
+    PushStringLiteral(envPtr, "");
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclCompileVariableCmd --
+ *
+ *	Procedure called to compile the "variable" command.
+ *
+ * Results:
+ *	Returns TCL_OK for a successful compile. Returns TCL_ERROR to defer
+ *	evaluation to runtime.
+ *
+ * Side effects:
+ *	Instructions are added to envPtr to execute the "variable" command at
+ *	runtime.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclCompileVariableCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    Tcl_Token *varTokenPtr, *valueTokenPtr;
+    int localIndex, numWords, i;
+    DefineLineInformation;	/* TIP #280 */
+
+    numWords = parsePtr->numWords;
+    if (numWords < 2) {
+	return TCL_ERROR;
+    }
+
+    /*
+     * Bail out if not compiling a proc body
+     */
+
+    if (envPtr->procPtr == NULL) {
+	return TCL_ERROR;
+    }
+
+    /*
+     * Loop over the (var, value) pairs.
+     */
+
+    valueTokenPtr = parsePtr->tokenPtr;
+    for (i=1; i<numWords; i+=2) {
+	varTokenPtr = TokenAfter(valueTokenPtr);
+	valueTokenPtr = TokenAfter(varTokenPtr);
+
+	localIndex = IndexTailVarIfKnown(interp, varTokenPtr, envPtr);
+
+	if (localIndex < 0) {
+	    return TCL_ERROR;
+	}
+
+	/* TODO: Consider what value can pass throug the 
+	 * IndexTailVarIfKnown() screen.  Full CompileWord()
+	 * likely does not apply here.  Push known value instead. */
+	CompileWord(envPtr, varTokenPtr, interp, i);
+	TclEmitInstInt4(	INST_VARIABLE, localIndex,	envPtr);
+
+	if (i+1 < numWords) {
+	    /*
+	     * A value has been given: set the variable, pop the value
+	     */
+
+	    CompileWord(envPtr, valueTokenPtr, interp, i+1);
+	    Emit14Inst(		INST_STORE_SCALAR, localIndex,	envPtr);
+	    TclEmitOpcode(	INST_POP,			envPtr);
+	}
+    }
+
+    /*
+     * Set the result to empty
+     */
+
+    PushStringLiteral(envPtr, "");
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * IndexTailVarIfKnown --
+ *
+ *	Procedure used in compiling [global] and [variable] commands. It
+ *	inspects the variable name described by varTokenPtr and, if the tail
+ *	is known at compile time, defines a corresponding local variable.
+ *
+ * Results:
+ *	Returns the variable's index in the table of compiled locals if the
+ *	tail is known at compile time, or -1 otherwise.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+static int
+IndexTailVarIfKnown(
+    Tcl_Interp *interp,
+    Tcl_Token *varTokenPtr,	/* Token representing the variable name */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    Tcl_Obj *tailPtr;
+    const char *tailName, *p;
+    int len, n = varTokenPtr->numComponents;
+    Tcl_Token *lastTokenPtr;
+    int full, localIndex;
+
+    /*
+     * Determine if the tail is (a) known at compile time, and (b) not an
+     * array element. Should any of these fail, return an error so that the
+     * non-compiled command will be called at runtime.
+     *
+     * In order for the tail to be known at compile time, the last token in
+     * the word has to be constant and contain "::" if it is not the only one.
+     */
+
+    if (!EnvHasLVT(envPtr)) {
+	return -1;
+    }
+
+    TclNewObj(tailPtr);
+    if (TclWordKnownAtCompileTime(varTokenPtr, tailPtr)) {
+	full = 1;
+	lastTokenPtr = varTokenPtr;
+    } else {
+	full = 0;
+	lastTokenPtr = varTokenPtr + n;
+	if (!TclWordKnownAtCompileTime(lastTokenPtr, tailPtr)) {
+	    Tcl_DecrRefCount(tailPtr);
+	    return -1;
+	}
+    }
+
+    tailName = TclGetStringFromObj(tailPtr, &len);
+
+    if (len) {
+	if (*(tailName+len-1) == ')') {
+	    /*
+	     * Possible array: bail out
+	     */
+
+	    Tcl_DecrRefCount(tailPtr);
+	    return -1;
+	}
+
+	/*
+	 * Get the tail: immediately after the last '::'
+	 */
+
+	for (p = tailName + len -1; p > tailName; p--) {
+	    if ((*p == ':') && (*(p-1) == ':')) {
+		p++;
+		break;
+	    }
+	}
+	if (!full && (p == tailName)) {
+	    /*
+	     * No :: in the last component.
+	     */
+
+	    Tcl_DecrRefCount(tailPtr);
+	    return -1;
+	}
+	len -= p - tailName;
+	tailName = p;
+    }
+
+    localIndex = TclFindCompiledLocal(tailName, len, 1, envPtr);
+    Tcl_DecrRefCount(tailPtr);
+    return localIndex;
+}
+
+/*
+ * ----------------------------------------------------------------------
+ *
+ * TclCompileObjectNextCmd, TclCompileObjectSelfCmd --
+ *
+ *	Compilations of the TclOO utility commands [next] and [self].
+ *
+ * ----------------------------------------------------------------------
+ */
+
+int
+TclCompileObjectNextCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    DefineLineInformation;	/* TIP #280 */
+    Tcl_Token *tokenPtr = parsePtr->tokenPtr;
+    int i;
+
+    if (parsePtr->numWords > 255) {
+	return TCL_ERROR;
+    }
+
+    for (i=0 ; i<parsePtr->numWords ; i++) {
+	CompileWord(envPtr, tokenPtr, interp, i);
+	tokenPtr = TokenAfter(tokenPtr);
+    }
+    TclEmitInstInt1(	INST_TCLOO_NEXT, i,		envPtr);
+    return TCL_OK;
+}
+
+int
+TclCompileObjectSelfCmd(
+    Tcl_Interp *interp,		/* Used for error reporting. */
+    Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
+				 * created by Tcl_ParseCommand. */
+    Command *cmdPtr,		/* Points to defintion of command being
+				 * compiled. */
+    CompileEnv *envPtr)		/* Holds resulting instructions. */
+{
+    /*
+     * We only handle [self] and [self object] (which is the same operation).
+     * These are the only very common operations on [self] for which
+     * bytecoding is at all reasonable.
+     */
+
+    if (parsePtr->numWords == 1) {
+	goto compileSelfObject;
+    } else if (parsePtr->numWords == 2) {
+	Tcl_Token *tokenPtr = TokenAfter(parsePtr->tokenPtr), *subcmd;
+
+	if (tokenPtr->type != TCL_TOKEN_SIMPLE_WORD || tokenPtr[1].size==0) {
+	    return TCL_ERROR;
+	}
+
+	subcmd = tokenPtr + 1;
+	if (strncmp(subcmd->start, "object", subcmd->size) == 0) {
+	    goto compileSelfObject;
+	} else if (strncmp(subcmd->start, "namespace", subcmd->size) == 0) {
+	    goto compileSelfNamespace;
+	}
+    }
+
+    /*
+     * Can't compile; handle with runtime call.
+     */
+
+    return TCL_ERROR;
+
+  compileSelfObject:
+
+    /*
+     * This delegates the entire problem to a single opcode.
+     */
+
+    TclEmitOpcode(		INST_TCLOO_SELF,		envPtr);
+    return TCL_OK;
+
+  compileSelfNamespace:
+
+    /*
+     * This is formally only correct with TclOO methods as they are currently
+     * implemented; it assumes that the current namespace is invariably when a
+     * TclOO context is present is the object's namespace, and that's
+     * technically only something that's a matter of current policy. But it
+     * avoids creating another opcode, so that's all good!
+     */
+
+    TclEmitOpcode(		INST_TCLOO_SELF,		envPtr);
+    TclEmitOpcode(		INST_POP,			envPtr);
+    TclEmitOpcode(		INST_NS_CURRENT,		envPtr);
+    return TCL_OK;
+}
+
+/*
+ * Local Variables:
+ * mode: c
+ * c-basic-offset: 4
+ * fill-column: 78
+ * End:
+ */