tclAssembly.c 131 KB
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/*
 * tclAssembly.c --
 *
 *	Assembler for Tcl bytecodes.
 *
 * This file contains the procedures that convert Tcl Assembly Language (TAL)
 * to a sequence of bytecode instructions for the Tcl execution engine.
 *
 * Copyright (c) 2010 by Ozgur Dogan Ugurlu.
 * Copyright (c) 2010 by Kevin B. Kenny.
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
 */

/*-
 *- THINGS TO DO:
 *- More instructions:
 *-   done - alternate exit point (affects stack and exception range checking)
 *-   break and continue - if exception ranges can be sorted out.
 *-   foreach_start4, foreach_step4
 *-   returnImm, returnStk
 *-   expandStart, expandStkTop, invokeExpanded, expandDrop
 *-   dictFirst, dictNext, dictDone
 *-   dictUpdateStart, dictUpdateEnd
 *-   jumpTable testing
 *-   syntax (?)
 *-   returnCodeBranch
 *-   tclooNext, tclooNextClass
 */

#include "tclInt.h"
#include "tclCompile.h"
#include "tclOOInt.h"

/*
 * Structure that represents a range of instructions in the bytecode.
 */

typedef struct CodeRange {
    int startOffset;		/* Start offset in the bytecode array */
    int endOffset;		/* End offset in the bytecode array */
} CodeRange;

/*
 * State identified for a basic block's catch context.
 */

typedef enum BasicBlockCatchState {
    BBCS_UNKNOWN = 0,		/* Catch context has not yet been identified */
    BBCS_NONE,			/* Block is outside of any catch */
    BBCS_INCATCH,		/* Block is within a catch context */
    BBCS_CAUGHT 		/* Block is within a catch context and
				 * may be executed after an exception fires */
} BasicBlockCatchState;

/*
 * Structure that defines a basic block - a linear sequence of bytecode
 * instructions with no jumps in or out (including not changing the
 * state of any exception range).
 */

typedef struct BasicBlock {
    int originalStartOffset;	/* Instruction offset before JUMP1s were
				 * substituted with JUMP4's */
    int startOffset;		/* Instruction offset of the start of the
				 * block */
    int startLine;		/* Line number in the input script of the
				 * instruction at the start of the block */
    int jumpOffset;		/* Bytecode offset of the 'jump' instruction
				 * that ends the block, or -1 if there is no
				 * jump. */
    int jumpLine;		/* Line number in the input script of the
				 * 'jump' instruction that ends the block, or
				 * -1 if there is no jump */
    struct BasicBlock* prevPtr;	/* Immediate predecessor of this block */
    struct BasicBlock* predecessor;
				/* Predecessor of this block in the spanning
				 * tree */
    struct BasicBlock* successor1;
				/* BasicBlock structure of the following
				 * block: NULL at the end of the bytecode
				 * sequence. */
    Tcl_Obj* jumpTarget;	/* Jump target label if the jump target is
				 * unresolved */
    int initialStackDepth;	/* Absolute stack depth on entry */
    int minStackDepth;		/* Low-water relative stack depth */
    int maxStackDepth;		/* High-water relative stack depth */
    int finalStackDepth;	/* Relative stack depth on exit */
    enum BasicBlockCatchState catchState;
				/* State of the block for 'catch' analysis */
    int catchDepth;		/* Number of nested catches in which the basic
				 * block appears */
    struct BasicBlock* enclosingCatch;
				/* BasicBlock structure of the last startCatch
				 * executed on a path to this block, or NULL
				 * if there is no enclosing catch */
    int foreignExceptionBase;	/* Base index of foreign exceptions */
    int foreignExceptionCount;	/* Count of foreign exceptions */
    ExceptionRange* foreignExceptions;
				/* ExceptionRange structures for exception
				 * ranges belonging to embedded scripts and
				 * expressions in this block */
    JumptableInfo* jtPtr;	/* Jump table at the end of this basic block */
    int flags;			/* Boolean flags */
} BasicBlock;

/*
 * Flags that pertain to a basic block.
 */

enum BasicBlockFlags {
    BB_VISITED = (1 << 0),	/* Block has been visited in the current
				 * traversal */
    BB_FALLTHRU = (1 << 1),	/* Control may pass from this block to a
				 * successor */
    BB_JUMP1 = (1 << 2),	/* Basic block ends with a 1-byte-offset jump
				 * and may need expansion */
    BB_JUMPTABLE = (1 << 3),	/* Basic block ends with a jump table */
    BB_BEGINCATCH = (1 << 4),	/* Block ends with a 'beginCatch' instruction,
				 * marking it as the start of a 'catch'
				 * sequence. The 'jumpTarget' is the exception
				 * exit from the catch block. */
    BB_ENDCATCH = (1 << 5)	/* Block ends with an 'endCatch' instruction,
				 * unwinding the catch from the exception
				 * stack. */
};

/*
 * Source instruction type recognized by the assembler.
 */

typedef enum TalInstType {
    ASSEM_1BYTE,		/* Fixed arity, 1-byte instruction */
    ASSEM_BEGIN_CATCH,		/* Begin catch: one 4-byte jump offset to be
				 * converted to appropriate exception
				 * ranges */
    ASSEM_BOOL,			/* One Boolean operand */
    ASSEM_BOOL_LVT4,		/* One Boolean, one 4-byte LVT ref. */
    ASSEM_CLOCK_READ,		/* 1-byte unsigned-integer case number, in the
				 * range 0-3 */
    ASSEM_CONCAT1,		/* 1-byte unsigned-integer operand count, must
				 * be strictly positive, consumes N, produces
				 * 1 */
    ASSEM_DICT_GET,		/* 'dict get' and related - consumes N+1
				 * operands, produces 1, N > 0 */
    ASSEM_DICT_SET,		/* specifies key count and LVT index, consumes
				 * N+1 operands, produces 1, N > 0 */
    ASSEM_DICT_UNSET,		/* specifies key count and LVT index, consumes
				 * N operands, produces 1, N > 0 */
    ASSEM_END_CATCH,		/* End catch. No args. Exception range popped
				 * from stack and stack pointer restored. */
    ASSEM_EVAL,			/* 'eval' - evaluate a constant script (by
				 * compiling it in line with the assembly
				 * code! I love Tcl!) */
    ASSEM_INDEX,		/* 4 byte operand, integer or end-integer */
    ASSEM_INVOKE,		/* 1- or 4-byte operand count, must be
				 * strictly positive, consumes N, produces
				 * 1. */
    ASSEM_JUMP,			/* Jump instructions */
    ASSEM_JUMP4,		/* Jump instructions forcing a 4-byte offset */
    ASSEM_JUMPTABLE,		/* Jumptable (switch -exact) */
    ASSEM_LABEL,		/* The assembly directive that defines a
				 * label */
    ASSEM_LINDEX_MULTI,		/* 4-byte operand count, must be strictly
				 * positive, consumes N, produces 1 */
    ASSEM_LIST,			/* 4-byte operand count, must be nonnegative,
				 * consumses N, produces 1 */
    ASSEM_LSET_FLAT,		/* 4-byte operand count, must be >= 3,
				 * consumes N, produces 1 */
    ASSEM_LVT,			/* One operand that references a local
				 * variable */
    ASSEM_LVT1,			/* One 1-byte operand that references a local
				 * variable */
    ASSEM_LVT1_SINT1,		/* One 1-byte operand that references a local
				 * variable, one signed-integer 1-byte
				 * operand */
    ASSEM_LVT4,			/* One 4-byte operand that references a local
				 * variable */
    ASSEM_OVER,			/* OVER: 4-byte operand count, consumes N+1,
				 * produces N+2 */
    ASSEM_PUSH,			/* one literal operand */
    ASSEM_REGEXP,		/* One Boolean operand, but weird mapping to
				 * call flags */
    ASSEM_REVERSE,		/* REVERSE: 4-byte operand count, consumes N,
				 * produces N */
    ASSEM_SINT1,		/* One 1-byte signed-integer operand
				 * (INCR_STK_IMM) */
    ASSEM_SINT4_LVT4		/* Signed 4-byte integer operand followed by
				 * LVT entry.  Fixed arity */
} TalInstType;

/*
 * Description of an instruction recognized by the assembler.
 */

typedef struct TalInstDesc {
    const char *name;		/* Name of instruction. */
    TalInstType instType;	/* The type of instruction */
    int tclInstCode;		/* Instruction code. For instructions having
				 * 1- and 4-byte variables, tclInstCode is
				 * ((1byte)<<8) || (4byte) */
    int operandsConsumed;	/* Number of operands consumed by the
				 * operation, or INT_MIN if the operation is
				 * variadic */
    int operandsProduced;	/* Number of operands produced by the
				 * operation. If negative, the operation has a
				 * net stack effect of -1-operandsProduced */
} TalInstDesc;

/*
 * Structure that holds the state of the assembler while generating code.
 */

typedef struct AssemblyEnv {
    CompileEnv* envPtr;		/* Compilation environment being used for code
				 * generation */
    Tcl_Parse* parsePtr;	/* Parse of the current line of source */
    Tcl_HashTable labelHash;	/* Hash table whose keys are labels and whose
				 * values are 'label' objects storing the code
				 * offsets of the labels. */
    int cmdLine;		/* Current line number within the assembly
				 * code */
    int* clNext;		/* Invisible continuation line for
				 * [info frame] */
    BasicBlock* head_bb;	/* First basic block in the code */
    BasicBlock* curr_bb;	/* Current basic block */
    int maxDepth;		/* Maximum stack depth encountered */
    int curCatchDepth;		/* Current depth of catches */
    int maxCatchDepth;		/* Maximum depth of catches encountered */
    int flags;			/* Compilation flags (TCL_EVAL_DIRECT) */
} AssemblyEnv;

/*
 * Static functions defined in this file.
 */

static void		AddBasicBlockRangeToErrorInfo(AssemblyEnv*,
			    BasicBlock*);
static BasicBlock *	AllocBB(AssemblyEnv*);
static int		AssembleOneLine(AssemblyEnv* envPtr);
static void		BBAdjustStackDepth(BasicBlock* bbPtr, int consumed,
			    int produced);
static void		BBUpdateStackReqs(BasicBlock* bbPtr, int tblIdx,
			    int count);
static void		BBEmitInstInt1(AssemblyEnv* assemEnvPtr, int tblIdx,
			    int opnd, int count);
static void		BBEmitInstInt4(AssemblyEnv* assemEnvPtr, int tblIdx,
			    int opnd, int count);
static void		BBEmitInst1or4(AssemblyEnv* assemEnvPtr, int tblIdx,
			    int param, int count);
static void		BBEmitOpcode(AssemblyEnv* assemEnvPtr, int tblIdx,
			    int count);
static int		BuildExceptionRanges(AssemblyEnv* assemEnvPtr);
static int		CalculateJumpRelocations(AssemblyEnv*, int*);
static int		CheckForUnclosedCatches(AssemblyEnv*);
static int		CheckForThrowInWrongContext(AssemblyEnv*);
static int		CheckNonThrowingBlock(AssemblyEnv*, BasicBlock*);
static int		BytecodeMightThrow(unsigned char);
static int		CheckJumpTableLabels(AssemblyEnv*, BasicBlock*);
static int		CheckNamespaceQualifiers(Tcl_Interp*, const char*,
			    int);
static int		CheckNonNegative(Tcl_Interp*, int);
static int		CheckOneByte(Tcl_Interp*, int);
static int		CheckSignedOneByte(Tcl_Interp*, int);
static int		CheckStack(AssemblyEnv*);
static int		CheckStrictlyPositive(Tcl_Interp*, int);
static ByteCode *	CompileAssembleObj(Tcl_Interp *interp,
			    Tcl_Obj *objPtr);
static void		CompileEmbeddedScript(AssemblyEnv*, Tcl_Token*,
			    const TalInstDesc*);
static int		DefineLabel(AssemblyEnv* envPtr, const char* label);
static void		DeleteMirrorJumpTable(JumptableInfo* jtPtr);
static void		DupAssembleCodeInternalRep(Tcl_Obj* src,
			    Tcl_Obj* dest);
static void		FillInJumpOffsets(AssemblyEnv*);
static int		CreateMirrorJumpTable(AssemblyEnv* assemEnvPtr,
			    Tcl_Obj* jumpTable);
static int		FindLocalVar(AssemblyEnv* envPtr,
			    Tcl_Token** tokenPtrPtr);
static int		FinishAssembly(AssemblyEnv*);
static void		FreeAssembleCodeInternalRep(Tcl_Obj *objPtr);
static void		FreeAssemblyEnv(AssemblyEnv*);
static int		GetBooleanOperand(AssemblyEnv*, Tcl_Token**, int*);
static int		GetListIndexOperand(AssemblyEnv*, Tcl_Token**, int*);
static int		GetIntegerOperand(AssemblyEnv*, Tcl_Token**, int*);
static int		GetNextOperand(AssemblyEnv*, Tcl_Token**, Tcl_Obj**);
static void		LookForFreshCatches(BasicBlock*, BasicBlock**);
static void		MoveCodeForJumps(AssemblyEnv*, int);
static void		MoveExceptionRangesToBasicBlock(AssemblyEnv*, int,
			    int);
static AssemblyEnv*	NewAssemblyEnv(CompileEnv*, int);
static int		ProcessCatches(AssemblyEnv*);
static int		ProcessCatchesInBasicBlock(AssemblyEnv*, BasicBlock*,
			    BasicBlock*, enum BasicBlockCatchState, int);
static void		ResetVisitedBasicBlocks(AssemblyEnv*);
static void		ResolveJumpTableTargets(AssemblyEnv*, BasicBlock*);
static void		ReportUndefinedLabel(AssemblyEnv*, BasicBlock*,
			    Tcl_Obj*);
static void		RestoreEmbeddedExceptionRanges(AssemblyEnv*);
static int		StackCheckBasicBlock(AssemblyEnv*, BasicBlock *,
			    BasicBlock *, int);
static BasicBlock*	StartBasicBlock(AssemblyEnv*, int fallthrough,
			    Tcl_Obj* jumpLabel);
/* static int		AdvanceIp(const unsigned char *pc); */
static int		StackCheckBasicBlock(AssemblyEnv*, BasicBlock *,
			    BasicBlock *, int);
static int		StackCheckExit(AssemblyEnv*);
static void		StackFreshCatches(AssemblyEnv*, BasicBlock*, int,
			    BasicBlock**, int*);
static void		SyncStackDepth(AssemblyEnv*);
static int		TclAssembleCode(CompileEnv* envPtr, const char* code,
			    int codeLen, int flags);
static void		UnstackExpiredCatches(CompileEnv*, BasicBlock*, int,
			    BasicBlock**, int*);

/*
 * Tcl_ObjType that describes bytecode emitted by the assembler.
 */

static const Tcl_ObjType assembleCodeType = {
    "assemblecode",
    FreeAssembleCodeInternalRep, /* freeIntRepProc */
    DupAssembleCodeInternalRep,	 /* dupIntRepProc */
    NULL,			 /* updateStringProc */
    NULL			 /* setFromAnyProc */
};

/*
 * Source instructions recognized in the Tcl Assembly Language (TAL)
 */

static const TalInstDesc TalInstructionTable[] = {
    /* PUSH must be first, see the code near the end of TclAssembleCode */
    {"push",		ASSEM_PUSH,	(INST_PUSH1<<8
					 | INST_PUSH4),		0,	1},

    {"add",		ASSEM_1BYTE,	INST_ADD,		2,	1},
    {"append",		ASSEM_LVT,	(INST_APPEND_SCALAR1<<8
					 | INST_APPEND_SCALAR4),1,	1},
    {"appendArray",	ASSEM_LVT,	(INST_APPEND_ARRAY1<<8
					 | INST_APPEND_ARRAY4),	2,	1},
    {"appendArrayStk",	ASSEM_1BYTE,	INST_APPEND_ARRAY_STK,	3,	1},
    {"appendStk",	ASSEM_1BYTE,	INST_APPEND_STK,	2,	1},
    {"arrayExistsImm",	ASSEM_LVT4,	INST_ARRAY_EXISTS_IMM,	0,	1},
    {"arrayExistsStk",	ASSEM_1BYTE,	INST_ARRAY_EXISTS_STK,	1,	1},
    {"arrayMakeImm",	ASSEM_LVT4,	INST_ARRAY_MAKE_IMM,	0,	0},
    {"arrayMakeStk",	ASSEM_1BYTE,	INST_ARRAY_MAKE_STK,	1,	0},
    {"beginCatch",	ASSEM_BEGIN_CATCH,
					INST_BEGIN_CATCH4,	0,	0},
    {"bitand",		ASSEM_1BYTE,	INST_BITAND,		2,	1},
    {"bitnot",		ASSEM_1BYTE,	INST_BITNOT,		1,	1},
    {"bitor",		ASSEM_1BYTE,	INST_BITOR,		2,	1},
    {"bitxor",		ASSEM_1BYTE,	INST_BITXOR,		2,	1},
    {"clockRead",	ASSEM_CLOCK_READ, INST_CLOCK_READ,	0,	1},
    {"concat",		ASSEM_CONCAT1,	INST_STR_CONCAT1,	INT_MIN,1},
    {"concatStk",	ASSEM_LIST,	INST_CONCAT_STK,	INT_MIN,1},
    {"coroName",	ASSEM_1BYTE,	INST_COROUTINE_NAME,	0,	1},
    {"currentNamespace",ASSEM_1BYTE,	INST_NS_CURRENT,	0,	1},
    {"dictAppend",	ASSEM_LVT4,	INST_DICT_APPEND,	2,	1},
    {"dictExists",	ASSEM_DICT_GET, INST_DICT_EXISTS,	INT_MIN,1},
    {"dictExpand",	ASSEM_1BYTE,	INST_DICT_EXPAND,	3,	1},
    {"dictGet",		ASSEM_DICT_GET, INST_DICT_GET,		INT_MIN,1},
    {"dictIncrImm",	ASSEM_SINT4_LVT4,
					INST_DICT_INCR_IMM,	1,	1},
    {"dictLappend",	ASSEM_LVT4,	INST_DICT_LAPPEND,	2,	1},
    {"dictRecombineStk",ASSEM_1BYTE,	INST_DICT_RECOMBINE_STK,3,	0},
    {"dictRecombineImm",ASSEM_LVT4,	INST_DICT_RECOMBINE_IMM,2,	0},
    {"dictSet",		ASSEM_DICT_SET, INST_DICT_SET,		INT_MIN,1},
    {"dictUnset",	ASSEM_DICT_UNSET,
					INST_DICT_UNSET,	INT_MIN,1},
    {"div",		ASSEM_1BYTE,	INST_DIV,		2,	1},
    {"dup",		ASSEM_1BYTE,	INST_DUP,		1,	2},
    {"endCatch",	ASSEM_END_CATCH,INST_END_CATCH,		0,	0},
    {"eq",		ASSEM_1BYTE,	INST_EQ,		2,	1},
    {"eval",		ASSEM_EVAL,	INST_EVAL_STK,		1,	1},
    {"evalStk",		ASSEM_1BYTE,	INST_EVAL_STK,		1,	1},
    {"exist",		ASSEM_LVT4,	INST_EXIST_SCALAR,	0,	1},
    {"existArray",	ASSEM_LVT4,	INST_EXIST_ARRAY,	1,	1},
    {"existArrayStk",	ASSEM_1BYTE,	INST_EXIST_ARRAY_STK,	2,	1},
    {"existStk",	ASSEM_1BYTE,	INST_EXIST_STK,		1,	1},
    {"expon",		ASSEM_1BYTE,	INST_EXPON,		2,	1},
    {"expr",		ASSEM_EVAL,	INST_EXPR_STK,		1,	1},
    {"exprStk",		ASSEM_1BYTE,	INST_EXPR_STK,		1,	1},
    {"ge",		ASSEM_1BYTE,	INST_GE,		2,	1},
    {"gt",		ASSEM_1BYTE,	INST_GT,		2,	1},
    {"incr",		ASSEM_LVT1,	INST_INCR_SCALAR1,	1,	1},
    {"incrArray",	ASSEM_LVT1,	INST_INCR_ARRAY1,	2,	1},
    {"incrArrayImm",	ASSEM_LVT1_SINT1,
					INST_INCR_ARRAY1_IMM,	1,	1},
    {"incrArrayStk",	ASSEM_1BYTE,	INST_INCR_ARRAY_STK,	3,	1},
    {"incrArrayStkImm", ASSEM_SINT1,	INST_INCR_ARRAY_STK_IMM,2,	1},
    {"incrImm",		ASSEM_LVT1_SINT1,
					INST_INCR_SCALAR1_IMM,	0,	1},
    {"incrStk",		ASSEM_1BYTE,	INST_INCR_STK,		2,	1},
    {"incrStkImm",	ASSEM_SINT1,	INST_INCR_STK_IMM,	1,	1},
    {"infoLevelArgs",	ASSEM_1BYTE,	INST_INFO_LEVEL_ARGS,	1,	1},
    {"infoLevelNumber",	ASSEM_1BYTE,	INST_INFO_LEVEL_NUM,	0,	1},
    {"invokeStk",	ASSEM_INVOKE,	(INST_INVOKE_STK1 << 8
					 | INST_INVOKE_STK4),	INT_MIN,1},
    {"jump",		ASSEM_JUMP,	INST_JUMP1,		0,	0},
    {"jump4",		ASSEM_JUMP4,	INST_JUMP4,		0,	0},
    {"jumpFalse",	ASSEM_JUMP,	INST_JUMP_FALSE1,	1,	0},
    {"jumpFalse4",	ASSEM_JUMP4,	INST_JUMP_FALSE4,	1,	0},
    {"jumpTable",	ASSEM_JUMPTABLE,INST_JUMP_TABLE,	1,	0},
    {"jumpTrue",	ASSEM_JUMP,	INST_JUMP_TRUE1,	1,	0},
    {"jumpTrue4",	ASSEM_JUMP4,	INST_JUMP_TRUE4,	1,	0},
    {"label",		ASSEM_LABEL,	0,			0,	0},
    {"land",		ASSEM_1BYTE,	INST_LAND,		2,	1},
    {"lappend",		ASSEM_LVT,	(INST_LAPPEND_SCALAR1<<8
					 | INST_LAPPEND_SCALAR4),
								1,	1},
    {"lappendArray",	ASSEM_LVT,	(INST_LAPPEND_ARRAY1<<8
					 | INST_LAPPEND_ARRAY4),2,	1},
    {"lappendArrayStk", ASSEM_1BYTE,	INST_LAPPEND_ARRAY_STK,	3,	1},
    {"lappendList",	ASSEM_LVT4,	INST_LAPPEND_LIST,	1,	1},
    {"lappendListArray",ASSEM_LVT4,	INST_LAPPEND_LIST_ARRAY,2,	1},
    {"lappendListArrayStk", ASSEM_1BYTE,INST_LAPPEND_LIST_ARRAY_STK, 3,	1},
    {"lappendListStk",	ASSEM_1BYTE,	INST_LAPPEND_LIST_STK,	2,	1},
    {"lappendStk",	ASSEM_1BYTE,	INST_LAPPEND_STK,	2,	1},
    {"le",		ASSEM_1BYTE,	INST_LE,		2,	1},
    {"lindexMulti",	ASSEM_LINDEX_MULTI,
					INST_LIST_INDEX_MULTI,	INT_MIN,1},
    {"list",		ASSEM_LIST,	INST_LIST,		INT_MIN,1},
    {"listConcat",	ASSEM_1BYTE,	INST_LIST_CONCAT,	2,	1},
    {"listIn",		ASSEM_1BYTE,	INST_LIST_IN,		2,	1},
    {"listIndex",	ASSEM_1BYTE,	INST_LIST_INDEX,	2,	1},
    {"listIndexImm",	ASSEM_INDEX,	INST_LIST_INDEX_IMM,	1,	1},
    {"listLength",	ASSEM_1BYTE,	INST_LIST_LENGTH,	1,	1},
    {"listNotIn",	ASSEM_1BYTE,	INST_LIST_NOT_IN,	2,	1},
    {"load",		ASSEM_LVT,	(INST_LOAD_SCALAR1 << 8
					 | INST_LOAD_SCALAR4),	0,	1},
    {"loadArray",	ASSEM_LVT,	(INST_LOAD_ARRAY1<<8
					 | INST_LOAD_ARRAY4),	1,	1},
    {"loadArrayStk",	ASSEM_1BYTE,	INST_LOAD_ARRAY_STK,	2,	1},
    {"loadStk",		ASSEM_1BYTE,	INST_LOAD_STK,		1,	1},
    {"lor",		ASSEM_1BYTE,	INST_LOR,		2,	1},
    {"lsetFlat",	ASSEM_LSET_FLAT,INST_LSET_FLAT,		INT_MIN,1},
    {"lsetList",	ASSEM_1BYTE,	INST_LSET_LIST,		3,	1},
    {"lshift",		ASSEM_1BYTE,	INST_LSHIFT,		2,	1},
    {"lt",		ASSEM_1BYTE,	INST_LT,		2,	1},
    {"mod",		ASSEM_1BYTE,	INST_MOD,		2,	1},
    {"mult",		ASSEM_1BYTE,	INST_MULT,		2,	1},
    {"neq",		ASSEM_1BYTE,	INST_NEQ,		2,	1},
    {"nop",		ASSEM_1BYTE,	INST_NOP,		0,	0},
    {"not",		ASSEM_1BYTE,	INST_LNOT,		1,	1},
    {"nsupvar",		ASSEM_LVT4,	INST_NSUPVAR,		2,	1},
    {"numericType",	ASSEM_1BYTE,	INST_NUM_TYPE,		1,	1},
    {"originCmd",	ASSEM_1BYTE,	INST_ORIGIN_COMMAND,	1,	1},
    {"over",		ASSEM_OVER,	INST_OVER,		INT_MIN,-1-1},
    {"pop",		ASSEM_1BYTE,	INST_POP,		1,	0},
    {"pushReturnCode",	ASSEM_1BYTE,	INST_PUSH_RETURN_CODE,	0,	1},
    {"pushReturnOpts",	ASSEM_1BYTE,	INST_PUSH_RETURN_OPTIONS,
								0,	1},
    {"pushResult",	ASSEM_1BYTE,	INST_PUSH_RESULT,	0,	1},
    {"regexp",		ASSEM_REGEXP,	INST_REGEXP,		2,	1},
    {"resolveCmd",	ASSEM_1BYTE,	INST_RESOLVE_COMMAND,	1,	1},
    {"reverse",		ASSEM_REVERSE,	INST_REVERSE,		INT_MIN,-1-0},
    {"rshift",		ASSEM_1BYTE,	INST_RSHIFT,		2,	1},
    {"store",		ASSEM_LVT,	(INST_STORE_SCALAR1<<8
					 | INST_STORE_SCALAR4),	1,	1},
    {"storeArray",	ASSEM_LVT,	(INST_STORE_ARRAY1<<8
					 | INST_STORE_ARRAY4),	2,	1},
    {"storeArrayStk",	ASSEM_1BYTE,	INST_STORE_ARRAY_STK,	3,	1},
    {"storeStk",	ASSEM_1BYTE,	INST_STORE_STK,		2,	1},
    {"strcaseLower",	ASSEM_1BYTE,	INST_STR_LOWER,		1,	1},
    {"strcaseTitle",	ASSEM_1BYTE,	INST_STR_TITLE,		1,	1},
    {"strcaseUpper",	ASSEM_1BYTE,	INST_STR_UPPER,		1,	1},
    {"strcmp",		ASSEM_1BYTE,	INST_STR_CMP,		2,	1},
    {"strcat",		ASSEM_CONCAT1,	INST_STR_CONCAT1,	INT_MIN,1},
    {"streq",		ASSEM_1BYTE,	INST_STR_EQ,		2,	1},
    {"strfind",		ASSEM_1BYTE,	INST_STR_FIND,		2,	1},
    {"strindex",	ASSEM_1BYTE,	INST_STR_INDEX,		2,	1},
    {"strlen",		ASSEM_1BYTE,	INST_STR_LEN,		1,	1},
    {"strmap",		ASSEM_1BYTE,	INST_STR_MAP,		3,	1},
    {"strmatch",	ASSEM_BOOL,	INST_STR_MATCH,		2,	1},
    {"strneq",		ASSEM_1BYTE,	INST_STR_NEQ,		2,	1},
    {"strrange",	ASSEM_1BYTE,	INST_STR_RANGE,		3,	1},
    {"strreplace",	ASSEM_1BYTE,	INST_STR_REPLACE,	4,	1},
    {"strrfind",	ASSEM_1BYTE,	INST_STR_FIND_LAST,	2,	1},
    {"strtrim",		ASSEM_1BYTE,	INST_STR_TRIM,		2,	1},
    {"strtrimLeft",	ASSEM_1BYTE,	INST_STR_TRIM_LEFT,	2,	1},
    {"strtrimRight",	ASSEM_1BYTE,	INST_STR_TRIM_RIGHT,	2,	1},
    {"sub",		ASSEM_1BYTE,	INST_SUB,		2,	1},
    {"tclooClass",	ASSEM_1BYTE,	INST_TCLOO_CLASS,	1,	1},
    {"tclooIsObject",	ASSEM_1BYTE,	INST_TCLOO_IS_OBJECT,	1,	1},
    {"tclooNamespace",	ASSEM_1BYTE,	INST_TCLOO_NS,		1,	1},
    {"tclooSelf",	ASSEM_1BYTE,	INST_TCLOO_SELF,	0,	1},
    {"tryCvtToBoolean",	ASSEM_1BYTE,	INST_TRY_CVT_TO_BOOLEAN,1,	2},
    {"tryCvtToNumeric",	ASSEM_1BYTE,	INST_TRY_CVT_TO_NUMERIC,1,	1},
    {"uminus",		ASSEM_1BYTE,	INST_UMINUS,		1,	1},
    {"unset",		ASSEM_BOOL_LVT4,INST_UNSET_SCALAR,	0,	0},
    {"unsetArray",	ASSEM_BOOL_LVT4,INST_UNSET_ARRAY,	1,	0},
    {"unsetArrayStk",	ASSEM_BOOL,	INST_UNSET_ARRAY_STK,	2,	0},
    {"unsetStk",	ASSEM_BOOL,	INST_UNSET_STK,		1,	0},
    {"uplus",		ASSEM_1BYTE,	INST_UPLUS,		1,	1},
    {"upvar",		ASSEM_LVT4,	INST_UPVAR,		2,	1},
    {"variable",	ASSEM_LVT4,	INST_VARIABLE,		1,	0},
    {"verifyDict",	ASSEM_1BYTE,	INST_DICT_VERIFY,	1,	0},
    {"yield",		ASSEM_1BYTE,	INST_YIELD,		1,	1},
    {NULL,		0,		0,			0,	0}
};

/*
 * List of instructions that cannot throw an exception under any
 * circumstances.  These instructions are the ones that are permissible after
 * an exception is caught but before the corresponding exception range is
 * popped from the stack.
 * The instructions must be in ascending order by numeric operation code.
 */

static const unsigned char NonThrowingByteCodes[] = {
    INST_PUSH1, INST_PUSH4, INST_POP, INST_DUP,			/* 1-4 */
    INST_JUMP1, INST_JUMP4,					/* 34-35 */
    INST_END_CATCH, INST_PUSH_RESULT, INST_PUSH_RETURN_CODE,	/* 70-72 */
    INST_LIST,							/* 79 */
    INST_OVER,							/* 95 */
    INST_PUSH_RETURN_OPTIONS,					/* 108 */
    INST_REVERSE,						/* 126 */
    INST_NOP,							/* 132 */
    INST_STR_MAP,						/* 143 */
    INST_STR_FIND,						/* 144 */
    INST_COROUTINE_NAME,					/* 149 */
    INST_NS_CURRENT,						/* 151 */
    INST_INFO_LEVEL_NUM,					/* 152 */
    INST_RESOLVE_COMMAND,					/* 154 */
    INST_STR_TRIM, INST_STR_TRIM_LEFT, INST_STR_TRIM_RIGHT,	/* 166-168 */
    INST_CONCAT_STK,						/* 169 */
    INST_STR_UPPER, INST_STR_LOWER, INST_STR_TITLE,		/* 170-172 */
    INST_NUM_TYPE						/* 180 */
};

/*
 * Helper macros.
 */

#if defined(TCL_DEBUG_ASSEMBLY) && defined(__GNUC__) && __GNUC__ > 2
#define DEBUG_PRINT(...)	fprintf(stderr, ##__VA_ARGS__);fflush(stderr)
#elif defined(__GNUC__) && __GNUC__ > 2
#define DEBUG_PRINT(...)	/* nothing */
#else
#define DEBUG_PRINT		/* nothing */
#endif

/*
 *-----------------------------------------------------------------------------
 *
 * BBAdjustStackDepth --
 *
 *	When an opcode is emitted, adjusts the stack information in the basic
 *	block to reflect the number of operands produced and consumed.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Updates minimum, maximum and final stack requirements in the basic
 *	block.
 *
 *-----------------------------------------------------------------------------
 */

static void
BBAdjustStackDepth(
    BasicBlock *bbPtr,		/* Structure describing the basic block */
    int consumed,		/* Count of operands consumed by the
				 * operation */
    int produced)		/* Count of operands produced by the
				 * operation */
{
    int depth = bbPtr->finalStackDepth;

    depth -= consumed;
    if (depth < bbPtr->minStackDepth) {
	bbPtr->minStackDepth = depth;
    }
    depth += produced;
    if (depth > bbPtr->maxStackDepth) {
	bbPtr->maxStackDepth = depth;
    }
    bbPtr->finalStackDepth = depth;
}

/*
 *-----------------------------------------------------------------------------
 *
 * BBUpdateStackReqs --
 *
 *	Updates the stack requirements of a basic block, given the opcode
 *	being emitted and an operand count.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Updates min, max and final stack requirements in the basic block.
 *
 * Notes:
 *	This function must not be called for instructions such as REVERSE and
 *	OVER that are variadic but do not consume all their operands. Instead,
 *	BBAdjustStackDepth should be called directly.
 *
 *	count should be provided only for variadic operations. For operations
 *	with known arity, count should be 0.
 *
 *-----------------------------------------------------------------------------
 */

static void
BBUpdateStackReqs(
    BasicBlock* bbPtr,		/* Structure describing the basic block */
    int tblIdx,			/* Index in TalInstructionTable of the
				 * operation being assembled */
    int count)			/* Count of operands for variadic insts */
{
    int consumed = TalInstructionTable[tblIdx].operandsConsumed;
    int produced = TalInstructionTable[tblIdx].operandsProduced;

    if (consumed == INT_MIN) {
	/*
	 * The instruction is variadic; it consumes 'count' operands.
	 */

	consumed = count;
    }
    if (produced < 0) {
	/*
	 * The instruction leaves some of its variadic operands on the stack,
	 * with net stack effect of '-1-produced'
	 */

	produced = consumed - produced - 1;
    }
    BBAdjustStackDepth(bbPtr, consumed, produced);
}

/*
 *-----------------------------------------------------------------------------
 *
 * BBEmitOpcode, BBEmitInstInt1, BBEmitInstInt4 --
 *
 *	Emit the opcode part of an instruction, or the entirety of an
 *	instruction with a 1- or 4-byte operand, and adjust stack
 *	requirements.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Stores instruction and operand in the operand stream, and adjusts the
 *	stack.
 *
 *-----------------------------------------------------------------------------
 */

static void
BBEmitOpcode(
    AssemblyEnv* assemEnvPtr,	/* Assembly environment */
    int tblIdx,			/* Table index in TalInstructionTable of op */
    int count)			/* Operand count for variadic ops */
{
    CompileEnv* envPtr = assemEnvPtr->envPtr;
				/* Compilation environment */
    BasicBlock* bbPtr = assemEnvPtr->curr_bb;
				/* Current basic block */
    int op = TalInstructionTable[tblIdx].tclInstCode & 0xff;

    /*
     * If this is the first instruction in a basic block, record its line
     * number.
     */

    if (bbPtr->startOffset == envPtr->codeNext - envPtr->codeStart) {
	bbPtr->startLine = assemEnvPtr->cmdLine;
    }

    TclEmitInt1(op, envPtr);
    TclUpdateAtCmdStart(op, envPtr);
    BBUpdateStackReqs(bbPtr, tblIdx, count);
}

static void
BBEmitInstInt1(
    AssemblyEnv* assemEnvPtr,	/* Assembly environment */
    int tblIdx,			/* Index in TalInstructionTable of op */
    int opnd,			/* 1-byte operand */
    int count)			/* Operand count for variadic ops */
{
    BBEmitOpcode(assemEnvPtr, tblIdx, count);
    TclEmitInt1(opnd, assemEnvPtr->envPtr);
}

static void
BBEmitInstInt4(
    AssemblyEnv* assemEnvPtr,	/* Assembly environment */
    int tblIdx,			/* Index in TalInstructionTable of op */
    int opnd,			/* 4-byte operand */
    int count)			/* Operand count for variadic ops */
{
    BBEmitOpcode(assemEnvPtr, tblIdx, count);
    TclEmitInt4(opnd, assemEnvPtr->envPtr);
}

/*
 *-----------------------------------------------------------------------------
 *
 * BBEmitInst1or4 --
 *
 *	Emits a 1- or 4-byte operation according to the magnitude of the
 *	operand.
 *
 *-----------------------------------------------------------------------------
 */

static void
BBEmitInst1or4(
    AssemblyEnv* assemEnvPtr,	/* Assembly environment */
    int tblIdx,			/* Index in TalInstructionTable of op */
    int param,			/* Variable-length parameter */
    int count)			/* Arity if variadic */
{
    CompileEnv* envPtr = assemEnvPtr->envPtr;
				/* Compilation environment */
    BasicBlock* bbPtr = assemEnvPtr->curr_bb;
				/* Current basic block */
    int op = TalInstructionTable[tblIdx].tclInstCode;

    if (param <= 0xff) {
	op >>= 8;
    } else {
	op &= 0xff;
    }
    TclEmitInt1(op, envPtr);
    if (param <= 0xff) {
	TclEmitInt1(param, envPtr);
    } else {
	TclEmitInt4(param, envPtr);
    }
    TclUpdateAtCmdStart(op, envPtr);
    BBUpdateStackReqs(bbPtr, tblIdx, count);
}

/*
 *-----------------------------------------------------------------------------
 *
 * Tcl_AssembleObjCmd, TclNRAssembleObjCmd --
 *
 *	Direct evaluation path for tcl::unsupported::assemble
 *
 * Results:
 *	Returns a standard Tcl result.
 *
 * Side effects:
 *	Assembles the code in objv[1], and executes it, so side effects
 *	include whatever the code does.
 *
 *-----------------------------------------------------------------------------
 */

int
Tcl_AssembleObjCmd(
    ClientData dummy,		/* Not used. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    /*
     * Boilerplate - make sure that there is an NRE trampoline on the C stack
     * because there needs to be one in place to execute bytecode.
     */

    return Tcl_NRCallObjProc(interp, TclNRAssembleObjCmd, dummy, objc, objv);
}

int
TclNRAssembleObjCmd(
    ClientData dummy,		/* Not used. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    ByteCode *codePtr;		/* Pointer to the bytecode to execute */
    Tcl_Obj* backtrace;		/* Object where extra error information is
				 * constructed. */

    if (objc != 2) {
	Tcl_WrongNumArgs(interp, 1, objv, "bytecodeList");
	return TCL_ERROR;
    }

    /*
     * Assemble the source to bytecode.
     */

    codePtr = CompileAssembleObj(interp, objv[1]);

    /*
     * On failure, report error line.
     */

    if (codePtr == NULL) {
	Tcl_AddErrorInfo(interp, "\n    (\"");
	Tcl_AppendObjToErrorInfo(interp, objv[0]);
	Tcl_AddErrorInfo(interp, "\" body, line ");
	backtrace = Tcl_NewIntObj(Tcl_GetErrorLine(interp));
	Tcl_AppendObjToErrorInfo(interp, backtrace);
	Tcl_AddErrorInfo(interp, ")");
	return TCL_ERROR;
    }

    /*
     * Use NRE to evaluate the bytecode from the trampoline.
     */

    return TclNRExecuteByteCode(interp, codePtr);
}

/*
 *-----------------------------------------------------------------------------
 *
 * CompileAssembleObj --
 *
 *	Sets up and assembles Tcl bytecode for the direct-execution path in
 *	the Tcl bytecode assembler.
 *
 * Results:
 *	Returns a pointer to the assembled code. Returns NULL if the assembly
 *	fails for any reason, with an appropriate error message in the
 *	interpreter.
 *
 *-----------------------------------------------------------------------------
 */

static ByteCode *
CompileAssembleObj(
    Tcl_Interp *interp,		/* Tcl interpreter */
    Tcl_Obj *objPtr)		/* Source code to assemble */
{
    Interp *iPtr = (Interp *) interp;
				/* Internals of the interpreter */
    CompileEnv compEnv;		/* Compilation environment structure */
    register ByteCode *codePtr = NULL;
				/* Bytecode resulting from the assembly */
    Namespace* namespacePtr;	/* Namespace in which variable and command
				 * names in the bytecode resolve */
    int status;			/* Status return from Tcl_AssembleCode */
    const char* source;		/* String representation of the source code */
    int sourceLen;		/* Length of the source code in bytes */


    /*
     * Get the expression ByteCode from the object. If it exists, make sure it
     * is valid in the current context.
     */

    if (objPtr->typePtr == &assembleCodeType) {
	namespacePtr = iPtr->varFramePtr->nsPtr;
	codePtr = objPtr->internalRep.twoPtrValue.ptr1;
	if (((Interp *) *codePtr->interpHandle == iPtr)
		&& (codePtr->compileEpoch == iPtr->compileEpoch)
		&& (codePtr->nsPtr == namespacePtr)
		&& (codePtr->nsEpoch == namespacePtr->resolverEpoch)
		&& (codePtr->localCachePtr
			== iPtr->varFramePtr->localCachePtr)) {
	    return codePtr;
	}

	/*
	 * Not valid, so free it and regenerate.
	 */

872
	TclFreeIntRep(objPtr);
873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896
    }

    /*
     * Set up the compilation environment, and assemble the code.
     */

    source = TclGetStringFromObj(objPtr, &sourceLen);
    TclInitCompileEnv(interp, &compEnv, source, sourceLen, NULL, 0);
    status = TclAssembleCode(&compEnv, source, sourceLen, TCL_EVAL_DIRECT);
    if (status != TCL_OK) {
	/*
	 * Assembly failed. Clean up and report the error.
	 */
	TclFreeCompileEnv(&compEnv);
	return NULL;
    }

    /*
     * Add a "done" instruction as the last instruction and change the object
     * into a ByteCode object. Ownership of the literal objects and aux data
     * items is given to the ByteCode object.
     */

    TclEmitOpcode(INST_DONE, &compEnv);
897
    codePtr = TclInitByteCodeObj(objPtr, &assembleCodeType, &compEnv);
898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304
    TclFreeCompileEnv(&compEnv);

    /*
     * Record the local variable context to which the bytecode pertains
     */

    if (iPtr->varFramePtr->localCachePtr) {
	codePtr->localCachePtr = iPtr->varFramePtr->localCachePtr;
	codePtr->localCachePtr->refCount++;
    }

    /*
     * Report on what the assembler did.
     */

#ifdef TCL_COMPILE_DEBUG
    if (tclTraceCompile >= 2) {
	TclPrintByteCodeObj(interp, objPtr);
	fflush(stdout);
    }
#endif /* TCL_COMPILE_DEBUG */

    return codePtr;
}

/*
 *-----------------------------------------------------------------------------
 *
 * TclCompileAssembleCmd --
 *
 *	Compilation procedure for the '::tcl::unsupported::assemble' command.
 *
 * Results:
 *	Returns a standard Tcl result.
 *
 * Side effects:
 *	Puts the result of assembling the code into the bytecode stream in
 *	'compileEnv'.
 *
 * This procedure makes sure that the command has a single arg, which is
 * constant. If that condition is met, the procedure calls TclAssembleCode to
 * produce bytecode for the given assembly code, and returns any error
 * resulting from the assembly.
 *
 *-----------------------------------------------------------------------------
 */

int
TclCompileAssembleCmd(
    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;	/* Token in the input script */

    int numCommands = envPtr->numCommands;
    int offset = envPtr->codeNext - envPtr->codeStart;
    int depth = envPtr->currStackDepth;

    /*
     * Make sure that the command has a single arg that is a simple word.
     */

    if (parsePtr->numWords != 2) {
	return TCL_ERROR;
    }
    tokenPtr = TokenAfter(parsePtr->tokenPtr);
    if (tokenPtr->type != TCL_TOKEN_SIMPLE_WORD) {
	return TCL_ERROR;
    }

    /*
     * Compile the code and convert any error from the compilation into
     * bytecode reporting the error;
     */

    if (TCL_ERROR == TclAssembleCode(envPtr, tokenPtr[1].start,
	    tokenPtr[1].size, TCL_EVAL_DIRECT)) {

	Tcl_AppendObjToErrorInfo(interp, Tcl_ObjPrintf(
		"\n    (\"%.*s\" body, line %d)",
		parsePtr->tokenPtr->size, parsePtr->tokenPtr->start,
		Tcl_GetErrorLine(interp)));
	envPtr->numCommands = numCommands;
	envPtr->codeNext = envPtr->codeStart + offset;
	envPtr->currStackDepth = depth;
	TclCompileSyntaxError(interp, envPtr);
    }
    return TCL_OK;
}

/*
 *-----------------------------------------------------------------------------
 *
 * TclAssembleCode --
 *
 *	Take a list of instructions in a Tcl_Obj, and assemble them to Tcl
 *	bytecodes
 *
 * Results:
 *	Returns TCL_OK on success, TCL_ERROR on failure.  If 'flags' includes
 *	TCL_EVAL_DIRECT, places an error message in the interpreter result.
 *
 * Side effects:
 *	Adds byte codes to the compile environment, and updates the
 *	environment's stack depth.
 *
 *-----------------------------------------------------------------------------
 */

static int
TclAssembleCode(
    CompileEnv *envPtr,		/* Compilation environment that is to receive
				 * the generated bytecode */
    const char* codePtr,	/* Assembly-language code to be processed */
    int codeLen,		/* Length of the code */
    int flags)			/* OR'ed combination of flags */
{
    Tcl_Interp* interp = (Tcl_Interp*) envPtr->iPtr;
				/* Tcl interpreter */
    /*
     * Walk through the assembly script using the Tcl parser.  Each 'command'
     * will be an instruction or assembly directive.
     */

    const char* instPtr = codePtr;
				/* Where to start looking for a line of code */
    const char* nextPtr;	/* Pointer to the end of the line of code */
    int bytesLeft = codeLen;	/* Number of bytes of source code remaining to
				 * be parsed */
    int status;			/* Tcl status return */
    AssemblyEnv* assemEnvPtr = NewAssemblyEnv(envPtr, flags);
    Tcl_Parse* parsePtr = assemEnvPtr->parsePtr;

    do {
	/*
	 * Parse out one command line from the assembly script.
	 */

	status = Tcl_ParseCommand(interp, instPtr, bytesLeft, 0, parsePtr);

	/*
	 * Report errors in the parse.
	 */

	if (status != TCL_OK) {
	    if (flags & TCL_EVAL_DIRECT) {
		Tcl_LogCommandInfo(interp, codePtr, parsePtr->commandStart,
			parsePtr->term + 1 - parsePtr->commandStart);
	    }
	    FreeAssemblyEnv(assemEnvPtr);
	    return TCL_ERROR;
	}

	/*
	 * Advance the pointers around any leading commentary.
	 */

	TclAdvanceLines(&assemEnvPtr->cmdLine, instPtr,
		parsePtr->commandStart);
	TclAdvanceContinuations(&assemEnvPtr->cmdLine, &assemEnvPtr->clNext,
		parsePtr->commandStart - envPtr->source);

	/*
	 * Process the line of code.
	 */

	if (parsePtr->numWords > 0) {
	    int instLen = parsePtr->commandSize;
		    /* Length in bytes of the current command */

	    if (parsePtr->term == parsePtr->commandStart + instLen - 1) {
		--instLen;
	    }

	    /*
	     * If tracing, show each line assembled as it happens.
	     */

#ifdef TCL_COMPILE_DEBUG
	    if ((tclTraceCompile >= 2) && (envPtr->procPtr == NULL)) {
		printf("  %4ld Assembling: ",
			(long)(envPtr->codeNext - envPtr->codeStart));
		TclPrintSource(stdout, parsePtr->commandStart,
			TclMin(instLen, 55));
		printf("\n");
	    }
#endif
	    if (AssembleOneLine(assemEnvPtr) != TCL_OK) {
		if (flags & TCL_EVAL_DIRECT) {
		    Tcl_LogCommandInfo(interp, codePtr,
			    parsePtr->commandStart, instLen);
		}
		Tcl_FreeParse(parsePtr);
		FreeAssemblyEnv(assemEnvPtr);
		return TCL_ERROR;
	    }
	}

	/*
	 * Advance to the next line of code.
	 */

	nextPtr = parsePtr->commandStart + parsePtr->commandSize;
	bytesLeft -= (nextPtr - instPtr);
	instPtr = nextPtr;
	TclAdvanceLines(&assemEnvPtr->cmdLine, parsePtr->commandStart,
		instPtr);
	TclAdvanceContinuations(&assemEnvPtr->cmdLine, &assemEnvPtr->clNext,
		instPtr - envPtr->source);
	Tcl_FreeParse(parsePtr);
    } while (bytesLeft > 0);

    /*
     * Done with parsing the code.
     */

    status = FinishAssembly(assemEnvPtr);
    FreeAssemblyEnv(assemEnvPtr);
    return status;
}

/*
 *-----------------------------------------------------------------------------
 *
 * NewAssemblyEnv --
 *
 *	Creates an environment for the assembler to run in.
 *
 * Results:
 *	Allocates, initialises and returns an assembler environment
 *
 *-----------------------------------------------------------------------------
 */

static AssemblyEnv*
NewAssemblyEnv(
    CompileEnv* envPtr,		/* Compilation environment being used for code
				 * generation*/
    int flags)			/* Compilation flags (TCL_EVAL_DIRECT) */
{
    Tcl_Interp* interp = (Tcl_Interp*) envPtr->iPtr;
				/* Tcl interpreter */
    AssemblyEnv* assemEnvPtr = TclStackAlloc(interp, sizeof(AssemblyEnv));
				/* Assembler environment under construction */
    Tcl_Parse* parsePtr = TclStackAlloc(interp, sizeof(Tcl_Parse));
				/* Parse of one line of assembly code */

    assemEnvPtr->envPtr = envPtr;
    assemEnvPtr->parsePtr = parsePtr;
    assemEnvPtr->cmdLine = 1;
    assemEnvPtr->clNext = envPtr->clNext;

    /*
     * Make the hashtables that store symbol resolution.
     */

    Tcl_InitHashTable(&assemEnvPtr->labelHash, TCL_STRING_KEYS);

    /*
     * Start the first basic block.
     */

    assemEnvPtr->curr_bb = NULL;
    assemEnvPtr->head_bb = AllocBB(assemEnvPtr);
    assemEnvPtr->curr_bb = assemEnvPtr->head_bb;
    assemEnvPtr->head_bb->startLine = 1;

    /*
     * Stash compilation flags.
     */

    assemEnvPtr->flags = flags;
    return assemEnvPtr;
}

/*
 *-----------------------------------------------------------------------------
 *
 * FreeAssemblyEnv --
 *
 *	Cleans up the assembler environment when assembly is complete.
 *
 *-----------------------------------------------------------------------------
 */

static void
FreeAssemblyEnv(
    AssemblyEnv* assemEnvPtr)	/* Environment to free */
{
    CompileEnv* envPtr = assemEnvPtr->envPtr;
				/* Compilation environment being used for code
				 * generation */
    Tcl_Interp* interp = (Tcl_Interp*) envPtr->iPtr;
				/* Tcl interpreter */
    BasicBlock* thisBB;		/* Pointer to a basic block being deleted */
    BasicBlock* nextBB;		/* Pointer to a deleted basic block's
				 * successor */

    /*
     * Free all the basic block structures.
     */

    for (thisBB = assemEnvPtr->head_bb; thisBB != NULL; thisBB = nextBB) {
	if (thisBB->jumpTarget != NULL) {
	    Tcl_DecrRefCount(thisBB->jumpTarget);
	}
	if (thisBB->foreignExceptions != NULL) {
	    ckfree(thisBB->foreignExceptions);
	}
	nextBB = thisBB->successor1;
	if (thisBB->jtPtr != NULL) {
	    DeleteMirrorJumpTable(thisBB->jtPtr);
	    thisBB->jtPtr = NULL;
	}
	ckfree(thisBB);
    }

    /*
     * Dispose what's left.
     */

    Tcl_DeleteHashTable(&assemEnvPtr->labelHash);
    TclStackFree(interp, assemEnvPtr->parsePtr);
    TclStackFree(interp, assemEnvPtr);
}

/*
 *-----------------------------------------------------------------------------
 *
 * AssembleOneLine --
 *
 *	Assembles a single command from an assembly language source.
 *
 * Results:
 *	Returns TCL_ERROR with an appropriate error message if the assembly
 *	fails. Returns TCL_OK if the assembly succeeds. Updates the assembly
 *	environment with the state of the assembly.
 *
 *-----------------------------------------------------------------------------
 */

static int
AssembleOneLine(
    AssemblyEnv* assemEnvPtr)	/* State of the assembly */
{
    CompileEnv* envPtr = assemEnvPtr->envPtr;
				/* Compilation environment being used for code
				 * gen */
    Tcl_Interp* interp = (Tcl_Interp*) envPtr->iPtr;
				/* Tcl interpreter */
    Tcl_Parse* parsePtr = assemEnvPtr->parsePtr;
				/* Parse of the line of code */
    Tcl_Token* tokenPtr;	/* Current token within the line of code */
    Tcl_Obj* instNameObj;	/* Name of the instruction */
    int tblIdx;			/* Index in TalInstructionTable of the
				 * instruction */
    enum TalInstType instType;	/* Type of the instruction */
    Tcl_Obj* operand1Obj = NULL;
				/* First operand to the instruction */
    const char* operand1;	/* String rep of the operand */
    int operand1Len;		/* String length of the operand */
    int opnd;			/* Integer representation of an operand */
    int litIndex;		/* Literal pool index of a constant */
    int localVar;		/* LVT index of a local variable */
    int flags;			/* Flags for a basic block */
    JumptableInfo* jtPtr;	/* Pointer to a jumptable */
    int infoIndex;		/* Index of the jumptable in auxdata */
    int status = TCL_ERROR;	/* Return value from this function */

    /*
     * Make sure that the instruction name is known at compile time.
     */

    tokenPtr = parsePtr->tokenPtr;
    if (GetNextOperand(assemEnvPtr, &tokenPtr, &instNameObj) != TCL_OK) {
	return TCL_ERROR;
    }

    /*
     * Look up the instruction name.
     */

    if (Tcl_GetIndexFromObjStruct(interp, instNameObj,
	    &TalInstructionTable[0].name, sizeof(TalInstDesc), "instruction",
	    TCL_EXACT, &tblIdx) != TCL_OK) {
	goto cleanup;
    }

    /*
     * Vector on the type of instruction being processed.
     */

    instType = TalInstructionTable[tblIdx].instType;
    switch (instType) {

    case ASSEM_PUSH:
	if (parsePtr->numWords != 2) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "value");
	    goto cleanup;
	}
	if (GetNextOperand(assemEnvPtr, &tokenPtr, &operand1Obj) != TCL_OK) {
	    goto cleanup;
	}
1305 1306
	operand1 = TclGetStringFromObj(operand1Obj, &operand1Len);
	litIndex = TclRegisterLiteral(envPtr, operand1, operand1Len, 0);
1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470
	BBEmitInst1or4(assemEnvPtr, tblIdx, litIndex, 0);
	break;

    case ASSEM_1BYTE:
	if (parsePtr->numWords != 1) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "");
	    goto cleanup;
	}
	BBEmitOpcode(assemEnvPtr, tblIdx, 0);
	break;

    case ASSEM_BEGIN_CATCH:
	/*
	 * Emit the BEGIN_CATCH instruction with the code offset of the
	 * exception branch target instead of the exception range index. The
	 * correct index will be generated and inserted later, when catches
	 * are being resolved.
	 */

	if (parsePtr->numWords != 2) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "label");
	    goto cleanup;
	}
	if (GetNextOperand(assemEnvPtr, &tokenPtr, &operand1Obj) != TCL_OK) {
	    goto cleanup;
	}
	assemEnvPtr->curr_bb->jumpLine = assemEnvPtr->cmdLine;
	assemEnvPtr->curr_bb->jumpOffset = envPtr->codeNext-envPtr->codeStart;
	BBEmitInstInt4(assemEnvPtr, tblIdx, 0, 0);
	assemEnvPtr->curr_bb->flags |= BB_BEGINCATCH;
	StartBasicBlock(assemEnvPtr, BB_FALLTHRU, operand1Obj);
	break;

    case ASSEM_BOOL:
	if (parsePtr->numWords != 2) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "boolean");
	    goto cleanup;
	}
	if (GetBooleanOperand(assemEnvPtr, &tokenPtr, &opnd) != TCL_OK) {
	    goto cleanup;
	}
	BBEmitInstInt1(assemEnvPtr, tblIdx, opnd, 0);
	break;

    case ASSEM_BOOL_LVT4:
	if (parsePtr->numWords != 3) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "boolean varName");
	    goto cleanup;
	}
	if (GetBooleanOperand(assemEnvPtr, &tokenPtr, &opnd) != TCL_OK) {
	    goto cleanup;
	}
	localVar = FindLocalVar(assemEnvPtr, &tokenPtr);
	if (localVar < 0) {
	    goto cleanup;
	}
	BBEmitInstInt1(assemEnvPtr, tblIdx, opnd, 0);
	TclEmitInt4(localVar, envPtr);
	break;

    case ASSEM_CLOCK_READ:
	if (parsePtr->numWords != 2) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "imm8");
	    goto cleanup;
	}
	if (GetIntegerOperand(assemEnvPtr, &tokenPtr, &opnd) != TCL_OK) {
	    goto cleanup;
	}
	if (opnd < 0 || opnd > 3) {
	    Tcl_SetObjResult(interp,
			     Tcl_NewStringObj("operand must be [0..3]", -1));
	    Tcl_SetErrorCode(interp, "TCL", "ASSEM", "OPERAND<0,>3", NULL);
	    goto cleanup;
	}
	BBEmitInstInt1(assemEnvPtr, tblIdx, opnd, opnd);
	break;

    case ASSEM_CONCAT1:
	if (parsePtr->numWords != 2) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "imm8");
	    goto cleanup;
	}
	if (GetIntegerOperand(assemEnvPtr, &tokenPtr, &opnd) != TCL_OK
		|| CheckOneByte(interp, opnd) != TCL_OK
		|| CheckStrictlyPositive(interp, opnd) != TCL_OK) {
	    goto cleanup;
	}
	BBEmitInstInt1(assemEnvPtr, tblIdx, opnd, opnd);
	break;

    case ASSEM_DICT_GET:
	if (parsePtr->numWords != 2) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "count");
	    goto cleanup;
	}
	if (GetIntegerOperand(assemEnvPtr, &tokenPtr, &opnd) != TCL_OK
		|| CheckStrictlyPositive(interp, opnd) != TCL_OK) {
	    goto cleanup;
	}
	BBEmitInstInt4(assemEnvPtr, tblIdx, opnd, opnd+1);
	break;

    case ASSEM_DICT_SET:
	if (parsePtr->numWords != 3) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "count varName");
	    goto cleanup;
	}
	if (GetIntegerOperand(assemEnvPtr, &tokenPtr, &opnd) != TCL_OK
		|| CheckStrictlyPositive(interp, opnd) != TCL_OK) {
	    goto cleanup;
	}
	localVar = FindLocalVar(assemEnvPtr, &tokenPtr);
	if (localVar < 0) {
	    goto cleanup;
	}
	BBEmitInstInt4(assemEnvPtr, tblIdx, opnd, opnd+1);
	TclEmitInt4(localVar, envPtr);
	break;

    case ASSEM_DICT_UNSET:
	if (parsePtr->numWords != 3) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "count varName");
	    goto cleanup;
	}
	if (GetIntegerOperand(assemEnvPtr, &tokenPtr, &opnd) != TCL_OK
		|| CheckStrictlyPositive(interp, opnd) != TCL_OK) {
	    goto cleanup;
	}
	localVar = FindLocalVar(assemEnvPtr, &tokenPtr);
	if (localVar < 0) {
	    goto cleanup;
	}
	BBEmitInstInt4(assemEnvPtr, tblIdx, opnd, opnd);
	TclEmitInt4(localVar, envPtr);
	break;

    case ASSEM_END_CATCH:
	if (parsePtr->numWords != 1) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "");
	    goto cleanup;
	}
	assemEnvPtr->curr_bb->flags |= BB_ENDCATCH;
	BBEmitOpcode(assemEnvPtr, tblIdx, 0);
	StartBasicBlock(assemEnvPtr, BB_FALLTHRU, NULL);
	break;

    case ASSEM_EVAL:
	/* TODO - Refactor this stuff into a subroutine that takes the inst
	 * code, the message ("script" or "expression") and an evaluator
	 * callback that calls TclCompileScript or TclCompileExpr. */

	if (parsePtr->numWords != 2) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj,
		    ((TalInstructionTable[tblIdx].tclInstCode
		    == INST_EVAL_STK) ? "script" : "expression"));
	    goto cleanup;
	}
	if (tokenPtr->type == TCL_TOKEN_SIMPLE_WORD) {
	    CompileEmbeddedScript(assemEnvPtr, tokenPtr+1,
		    TalInstructionTable+tblIdx);
	} else if (GetNextOperand(assemEnvPtr, &tokenPtr,
		&operand1Obj) != TCL_OK) {
	    goto cleanup;
	} else {
1471 1472
	    operand1 = TclGetStringFromObj(operand1Obj, &operand1Len);
	    litIndex = TclRegisterLiteral(envPtr, operand1, operand1Len, 0);
1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565

	    /*
	     * Assumes that PUSH is the first slot!
	     */

	    BBEmitInst1or4(assemEnvPtr, 0, litIndex, 0);
	    BBEmitOpcode(assemEnvPtr, tblIdx, 0);
	}
	break;

    case ASSEM_INVOKE:
	if (parsePtr->numWords != 2) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "count");
	    goto cleanup;
	}
	if (GetIntegerOperand(assemEnvPtr, &tokenPtr, &opnd) != TCL_OK
		|| CheckStrictlyPositive(interp, opnd) != TCL_OK) {
	    goto cleanup;
	}

	BBEmitInst1or4(assemEnvPtr, tblIdx, opnd, opnd);
	break;

    case ASSEM_JUMP:
    case ASSEM_JUMP4:
	if (parsePtr->numWords != 2) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "label");
	    goto cleanup;
	}
	if (GetNextOperand(assemEnvPtr, &tokenPtr, &operand1Obj) != TCL_OK) {
	    goto cleanup;
	}
	assemEnvPtr->curr_bb->jumpOffset = envPtr->codeNext-envPtr->codeStart;
	if (instType == ASSEM_JUMP) {
	    flags = BB_JUMP1;
	    BBEmitInstInt1(assemEnvPtr, tblIdx, 0, 0);
	} else {
	    flags = 0;
	    BBEmitInstInt4(assemEnvPtr, tblIdx, 0, 0);
	}

	/*
	 * Start a new basic block at the instruction following the jump.
	 */

	assemEnvPtr->curr_bb->jumpLine = assemEnvPtr->cmdLine;
	if (TalInstructionTable[tblIdx].operandsConsumed != 0) {
	    flags |= BB_FALLTHRU;
	}
	StartBasicBlock(assemEnvPtr, flags, operand1Obj);
	break;

    case ASSEM_JUMPTABLE:
	if (parsePtr->numWords != 2) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "table");
	    goto cleanup;
	}
	if (GetNextOperand(assemEnvPtr, &tokenPtr, &operand1Obj) != TCL_OK) {
	    goto cleanup;
	}

	jtPtr = ckalloc(sizeof(JumptableInfo));

	Tcl_InitHashTable(&jtPtr->hashTable, TCL_STRING_KEYS);
	assemEnvPtr->curr_bb->jumpLine = assemEnvPtr->cmdLine;
	assemEnvPtr->curr_bb->jumpOffset = envPtr->codeNext-envPtr->codeStart;
	DEBUG_PRINT("bb %p jumpLine %d jumpOffset %d\n",
		assemEnvPtr->curr_bb, assemEnvPtr->cmdLine,
		envPtr->codeNext - envPtr->codeStart);

	infoIndex = TclCreateAuxData(jtPtr, &tclJumptableInfoType, envPtr);
	DEBUG_PRINT("auxdata index=%d\n", infoIndex);

	BBEmitInstInt4(assemEnvPtr, tblIdx, infoIndex, 0);
	if (CreateMirrorJumpTable(assemEnvPtr, operand1Obj) != TCL_OK) {
	    goto cleanup;
	}
	StartBasicBlock(assemEnvPtr, BB_JUMPTABLE|BB_FALLTHRU, NULL);
	break;

    case ASSEM_LABEL:
	if (parsePtr->numWords != 2) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "name");
	    goto cleanup;
	}
	if (GetNextOperand(assemEnvPtr, &tokenPtr, &operand1Obj) != TCL_OK) {
	    goto cleanup;
	}

	/*
	 * Add the (label_name, address) pair to the hash table.
	 */

1566
	if (DefineLabel(assemEnvPtr, TclGetString(operand1Obj)) != TCL_OK) {
1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744
	    goto cleanup;
	}
	break;

    case ASSEM_LINDEX_MULTI:
	if (parsePtr->numWords != 2) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "count");
	    goto cleanup;
	}
	if (GetIntegerOperand(assemEnvPtr, &tokenPtr, &opnd) != TCL_OK
		|| CheckStrictlyPositive(interp, opnd) != TCL_OK) {
	    goto cleanup;
	}
	BBEmitInstInt4(assemEnvPtr, tblIdx, opnd, opnd);
	break;

    case ASSEM_LIST:
	if (parsePtr->numWords != 2) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "count");
	    goto cleanup;
	}
	if (GetIntegerOperand(assemEnvPtr, &tokenPtr, &opnd) != TCL_OK
		|| CheckNonNegative(interp, opnd) != TCL_OK) {
	    goto cleanup;
	}
	BBEmitInstInt4(assemEnvPtr, tblIdx, opnd, opnd);
	break;

    case ASSEM_INDEX:
	if (parsePtr->numWords != 2) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "count");
	    goto cleanup;
	}
	if (GetListIndexOperand(assemEnvPtr, &tokenPtr, &opnd) != TCL_OK) {
	    goto cleanup;
	}
	BBEmitInstInt4(assemEnvPtr, tblIdx, opnd, opnd);
	break;

    case ASSEM_LSET_FLAT:
	if (parsePtr->numWords != 2) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "count");
	    goto cleanup;
	}
	if (GetIntegerOperand(assemEnvPtr, &tokenPtr, &opnd) != TCL_OK) {
	    goto cleanup;
	}
	if (opnd < 2) {
	    if (assemEnvPtr->flags & TCL_EVAL_DIRECT) {
		Tcl_SetObjResult(interp,
			Tcl_NewStringObj("operand must be >=2", -1));
		Tcl_SetErrorCode(interp, "TCL", "ASSEM", "OPERAND>=2", NULL);
	    }
	    goto cleanup;
	}
	BBEmitInstInt4(assemEnvPtr, tblIdx, opnd, opnd);
	break;

    case ASSEM_LVT:
	if (parsePtr->numWords != 2) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "varname");
	    goto cleanup;
	}
	localVar = FindLocalVar(assemEnvPtr, &tokenPtr);
	if (localVar < 0) {
	    goto cleanup;
	}
	BBEmitInst1or4(assemEnvPtr, tblIdx, localVar, 0);
	break;

    case ASSEM_LVT1:
	if (parsePtr->numWords != 2) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "varname");
	    goto cleanup;
	}
	localVar = FindLocalVar(assemEnvPtr, &tokenPtr);
	if (localVar < 0 || CheckOneByte(interp, localVar)) {
	    goto cleanup;
	}
	BBEmitInstInt1(assemEnvPtr, tblIdx, localVar, 0);
	break;

    case ASSEM_LVT1_SINT1:
	if (parsePtr->numWords != 3) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "varName imm8");
	    goto cleanup;
	}
	localVar = FindLocalVar(assemEnvPtr, &tokenPtr);
	if (localVar < 0 || CheckOneByte(interp, localVar)
		|| GetIntegerOperand(assemEnvPtr, &tokenPtr, &opnd) != TCL_OK
		|| CheckSignedOneByte(interp, opnd)) {
	    goto cleanup;
	}
	BBEmitInstInt1(assemEnvPtr, tblIdx, localVar, 0);
	TclEmitInt1(opnd, envPtr);
	break;

    case ASSEM_LVT4:
	if (parsePtr->numWords != 2) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "varname");
	    goto cleanup;
	}
	localVar = FindLocalVar(assemEnvPtr, &tokenPtr);
	if (localVar < 0) {
	    goto cleanup;
	}
	BBEmitInstInt4(assemEnvPtr, tblIdx, localVar, 0);
	break;

    case ASSEM_OVER:
	if (parsePtr->numWords != 2) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "count");
	    goto cleanup;
	}
	if (GetIntegerOperand(assemEnvPtr, &tokenPtr, &opnd) != TCL_OK
		|| CheckNonNegative(interp, opnd) != TCL_OK) {
	    goto cleanup;
	}
	BBEmitInstInt4(assemEnvPtr, tblIdx, opnd, opnd+1);
	break;

    case ASSEM_REGEXP:
	if (parsePtr->numWords != 2) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "boolean");
	    goto cleanup;
	}
	if (GetBooleanOperand(assemEnvPtr, &tokenPtr, &opnd) != TCL_OK) {
	    goto cleanup;
	}
	{
	    int flags = TCL_REG_ADVANCED | (opnd ? TCL_REG_NOCASE : 0);

	    BBEmitInstInt1(assemEnvPtr, tblIdx, flags, 0);
	}
	break;

    case ASSEM_REVERSE:
	if (parsePtr->numWords != 2) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "count");
	    goto cleanup;
	}
	if (GetIntegerOperand(assemEnvPtr, &tokenPtr, &opnd) != TCL_OK
		|| CheckNonNegative(interp, opnd) != TCL_OK) {
	    goto cleanup;
	}
	BBEmitInstInt4(assemEnvPtr, tblIdx, opnd, opnd);
	break;

    case ASSEM_SINT1:
	if (parsePtr->numWords != 2) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "imm8");
	    goto cleanup;
	}
	if (GetIntegerOperand(assemEnvPtr, &tokenPtr, &opnd) != TCL_OK
		|| CheckSignedOneByte(interp, opnd) != TCL_OK) {
	    goto cleanup;
	}
	BBEmitInstInt1(assemEnvPtr, tblIdx, opnd, 0);
	break;

    case ASSEM_SINT4_LVT4:
	if (parsePtr->numWords != 3) {
	    Tcl_WrongNumArgs(interp, 1, &instNameObj, "count varName");
	    goto cleanup;
	}
	if (GetIntegerOperand(assemEnvPtr, &tokenPtr, &opnd) != TCL_OK) {
	    goto cleanup;
	}
	localVar = FindLocalVar(assemEnvPtr, &tokenPtr);
	if (localVar < 0) {
	    goto cleanup;
	}
	BBEmitInstInt4(assemEnvPtr, tblIdx, opnd, 0);
	TclEmitInt4(localVar, envPtr);
	break;

    default:
	Tcl_Panic("Instruction \"%s\" could not be found, can't happen\n",
1745
		TclGetString(instNameObj));
1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
    }

    status = TCL_OK;
 cleanup:
    Tcl_DecrRefCount(instNameObj);
    if (operand1Obj) {
	Tcl_DecrRefCount(operand1Obj);
    }
    return status;
}

/*
 *-----------------------------------------------------------------------------
 *
 * CompileEmbeddedScript --
 *
 *	Compile an embedded 'eval' or 'expr' that appears in assembly code.
 *
 * This procedure is called when the 'eval' or 'expr' assembly directive is
 * encountered, and the argument to the directive is a simple word that
 * requires no substitution. The appropriate compiler (TclCompileScript or
 * TclCompileExpr) is invoked recursively, and emits bytecode.
 *
 * Before the compiler is invoked, the compilation environment's stack
 * consumption is reset to zero. Upon return from the compilation, the net
 * stack effect of the compilation is in the compiler env, and this stack
 * effect is posted to the assembler environment. The compile environment's
 * stack consumption is then restored to what it was before (which is actually
 * the state of the stack on entry to the block of assembly code).
 *
 * Any exception ranges pushed by the compilation are copied to the basic
 * block and removed from the compiler environment. They will be rebuilt at
 * the end of assembly, when the exception stack depth is actually known.
 *
 *-----------------------------------------------------------------------------
 */

static void
CompileEmbeddedScript(
    AssemblyEnv* assemEnvPtr,	/* Assembly environment */
    Tcl_Token* tokenPtr,	/* Tcl_Token containing the script */
    const TalInstDesc* instPtr)	/* Instruction that determines whether
				 * the script is 'expr' or 'eval' */
{
    CompileEnv* envPtr = assemEnvPtr->envPtr;
				/* Compilation environment */
    Tcl_Interp* interp = (Tcl_Interp*) envPtr->iPtr;
				/* Tcl interpreter */

    /*
     * The expression or script is not only known at compile time, but
     * actually a "simple word". It can be compiled inline by invoking the
     * compiler recursively.
     *
     * Save away the stack depth and reset it before compiling the script.
     * We'll record the stack usage of the script in the BasicBlock, and
     * accumulate it together with the stack usage of the enclosing assembly
     * code.
     */

    int savedStackDepth = envPtr->currStackDepth;
    int savedMaxStackDepth = envPtr->maxStackDepth;
    int savedCodeIndex = envPtr->codeNext - envPtr->codeStart;
    int savedExceptArrayNext = envPtr->exceptArrayNext;

    envPtr->currStackDepth = 0;
    envPtr->maxStackDepth = 0;

    StartBasicBlock(assemEnvPtr, BB_FALLTHRU, NULL);
    switch(instPtr->tclInstCode) {
    case INST_EVAL_STK:
	TclCompileScript(interp, tokenPtr->start, tokenPtr->size, envPtr);
	break;
    case INST_EXPR_STK:
	TclCompileExpr(interp, tokenPtr->start, tokenPtr->size, envPtr, 1);
	break;
    default:
	Tcl_Panic("no ASSEM_EVAL case for %s (%d), can't happen",
		instPtr->name, instPtr->tclInstCode);
    }

    /*
     * Roll up the stack usage of the embedded block into the assembler
     * environment.
     */

    SyncStackDepth(assemEnvPtr);
    envPtr->currStackDepth = savedStackDepth;
    envPtr->maxStackDepth = savedMaxStackDepth;

    /*
     * Save any exception ranges that were pushed by the compiler; they will
     * need to be fixed up once the stack depth is known.
     */

    MoveExceptionRangesToBasicBlock(assemEnvPtr, savedCodeIndex,
	    savedExceptArrayNext);

    /*
     * Flush the current basic block.
     */

    StartBasicBlock(assemEnvPtr, BB_FALLTHRU, NULL);
}

/*
 *-----------------------------------------------------------------------------
 *
 * SyncStackDepth --
 *
 *	Copies the stack depth from the compile environment to a basic block.
 *
 * Side effects:
 *	Current and max stack depth in the current basic block are adjusted.
 *
 * This procedure is called on return from invoking the compiler for the
 * 'eval' and 'expr' operations. It adjusts the stack depth of the current
 * basic block to reflect the stack required by the just-compiled code.
 *
 *-----------------------------------------------------------------------------
 */

static void
SyncStackDepth(
    AssemblyEnv* assemEnvPtr)	/* Assembly environment */
{
    CompileEnv* envPtr = assemEnvPtr->envPtr;
				/* Compilation environment */
    BasicBlock* curr_bb = assemEnvPtr->curr_bb;
				/* Current basic block */
    int maxStackDepth = curr_bb->finalStackDepth + envPtr->maxStackDepth;
				/* Max stack depth in the basic block */

    if (maxStackDepth > curr_bb->maxStackDepth) {
	curr_bb->maxStackDepth = maxStackDepth;
    }
    curr_bb->finalStackDepth += envPtr->currStackDepth;
}

/*
 *-----------------------------------------------------------------------------
 *
 * MoveExceptionRangesToBasicBlock --
 *
 *	Removes exception ranges that were created by compiling an embedded
 *	script from the CompileEnv, and stores them in the BasicBlock. They
 *	will be reinstalled, at the correct stack depth, after control flow
 *	analysis is complete on the assembly code.
 *
 *-----------------------------------------------------------------------------
 */

static void
MoveExceptionRangesToBasicBlock(
    AssemblyEnv* assemEnvPtr,	/* Assembly environment */
    int savedCodeIndex,		/* Start of the embedded code */
    int savedExceptArrayNext)	/* Saved index of the end of the exception
				 * range array */
{
    CompileEnv* envPtr = assemEnvPtr->envPtr;
				/* Compilation environment */
    BasicBlock* curr_bb = assemEnvPtr->curr_bb;
				/* Current basic block */
    int exceptionCount = envPtr->exceptArrayNext - savedExceptArrayNext;
				/* Number of ranges that must be moved */
    int i;

    if (exceptionCount == 0) {
	/* Nothing to do */
	return;
    }

    /*
     * Save the exception ranges in the basic block. They will be re-added at
     * the conclusion of assembly; at this time, the INST_BEGIN_CATCH
     * instructions in the block will be adjusted from whatever range indices
     * they have [savedExceptArrayNext .. envPtr->exceptArrayNext) to the
     * indices that the exceptions acquire. The saved exception ranges are
     * converted to a relative nesting depth. The depth will be recomputed
     * once flow analysis has determined the actual stack depth of the block.
     */

    DEBUG_PRINT("basic block %p has %d exceptions starting at %d\n",
	    curr_bb, exceptionCount, savedExceptArrayNext);
    curr_bb->foreignExceptionBase = savedExceptArrayNext;
    curr_bb->foreignExceptionCount = exceptionCount;
    curr_bb->foreignExceptions =
	    ckalloc(exceptionCount * sizeof(ExceptionRange));
    memcpy(curr_bb->foreignExceptions,
	    envPtr->exceptArrayPtr + savedExceptArrayNext,
	    exceptionCount * sizeof(ExceptionRange));
    for (i = 0; i < exceptionCount; ++i) {
	curr_bb->foreignExceptions[i].nestingLevel -= envPtr->exceptDepth;
    }
    envPtr->exceptArrayNext = savedExceptArrayNext;
}

/*
 *-----------------------------------------------------------------------------
 *
 * CreateMirrorJumpTable --
 *
 *	Makes a jump table with comparison values and assembly code labels.
 *
 * Results:
 *	Returns a standard Tcl status, with an error message in the
 *	interpreter on error.
 *
 * Side effects:
 *	Initializes the jump table pointer in the current basic block to a
 *	JumptableInfo. The keys in the JumptableInfo are the comparison
 *	strings. The values, instead of being jump displacements, are
 *	Tcl_Obj's with the code labels.
 */

static int
CreateMirrorJumpTable(
    AssemblyEnv* assemEnvPtr,	/* Assembly environment */
    Tcl_Obj* jumps)		/* List of alternating keywords and labels */
{
    int objc;			/* Number of elements in the 'jumps' list */
    Tcl_Obj** objv;		/* Pointers to the elements in the list */
    CompileEnv* envPtr = assemEnvPtr->envPtr;
				/* Compilation environment */
    Tcl_Interp* interp = (Tcl_Interp*) envPtr->iPtr;
				/* Tcl interpreter */
    BasicBlock* bbPtr = assemEnvPtr->curr_bb;
				/* Current basic block */
    JumptableInfo* jtPtr;
    Tcl_HashTable* jtHashPtr;	/* Hashtable in the JumptableInfo */
    Tcl_HashEntry* hashEntry;	/* Entry for a key in the hashtable */
    int isNew;			/* Flag==1 if the key is not yet in the
				 * table. */
    int i;

    if (Tcl_ListObjGetElements(interp, jumps, &objc, &objv) != TCL_OK) {
	return TCL_ERROR;
    }
    if (objc % 2 != 0) {
	if (assemEnvPtr->flags & TCL_EVAL_DIRECT) {
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "jump table must have an even number of list elements",
		    -1));
	    Tcl_SetErrorCode(interp, "TCL", "ASSEM", "BADJUMPTABLE", NULL);
	}
	return TCL_ERROR;
    }

    /*
     * Allocate the jumptable.
     */

    jtPtr = ckalloc(sizeof(JumptableInfo));
    jtHashPtr = &jtPtr->hashTable;
    Tcl_InitHashTable(jtHashPtr, TCL_STRING_KEYS);

    /*
     * Fill the keys and labels into the table.
     */

    DEBUG_PRINT("jump table {\n");
    for (i = 0; i < objc; i+=2) {
2008 2009 2010
	DEBUG_PRINT("  %s -> %s\n", TclGetString(objv[i]),
		TclGetString(objv[i+1]));
	hashEntry = Tcl_CreateHashEntry(jtHashPtr, TclGetString(objv[i]),
2011 2012 2013 2014 2015
		&isNew);
	if (!isNew) {
	    if (assemEnvPtr->flags & TCL_EVAL_DIRECT) {
		Tcl_SetObjResult(interp, Tcl_ObjPrintf(
			"duplicate entry in jump table for \"%s\"",
2016
			TclGetString(objv[i])));
2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310
		Tcl_SetErrorCode(interp, "TCL", "ASSEM", "DUPJUMPTABLEENTRY");
		DeleteMirrorJumpTable(jtPtr);
		return TCL_ERROR;
	    }
	}
	Tcl_SetHashValue(hashEntry, objv[i+1]);
	Tcl_IncrRefCount(objv[i+1]);
    }
    DEBUG_PRINT("}\n");

    /*
     * Put the mirror jumptable in the basic block struct.
     */

    bbPtr->jtPtr = jtPtr;
    return TCL_OK;
}

/*
 *-----------------------------------------------------------------------------
 *
 * DeleteMirrorJumpTable --
 *
 *	Cleans up a jump table when the basic block is deleted.
 *
 *-----------------------------------------------------------------------------
 */

static void
DeleteMirrorJumpTable(
    JumptableInfo* jtPtr)
{
    Tcl_HashTable* jtHashPtr = &jtPtr->hashTable;
				/* Hash table pointer */
    Tcl_HashSearch search;	/* Hash search control */
    Tcl_HashEntry* entry;	/* Hash table entry containing a jump label */
    Tcl_Obj* label;		/* Jump label from the hash table */

    for (entry = Tcl_FirstHashEntry(jtHashPtr, &search);
	    entry != NULL;
	    entry = Tcl_NextHashEntry(&search)) {
	label = Tcl_GetHashValue(entry);
	Tcl_DecrRefCount(label);
	Tcl_SetHashValue(entry, NULL);
    }
    Tcl_DeleteHashTable(jtHashPtr);
    ckfree(jtPtr);
}

/*
 *-----------------------------------------------------------------------------
 *
 * GetNextOperand --
 *
 *	Retrieves the next operand in sequence from an assembly instruction,
 *	and makes sure that its value is known at compile time.
 *
 * Results:
 *	If successful, returns TCL_OK and leaves a Tcl_Obj with the operand
 *	text in *operandObjPtr. In case of failure, returns TCL_ERROR and
 *	leaves *operandObjPtr untouched.
 *
 * Side effects:
 *	Advances *tokenPtrPtr around the token just processed.
 *
 *-----------------------------------------------------------------------------
 */

static int
GetNextOperand(
    AssemblyEnv* assemEnvPtr,	/* Assembly environment */
    Tcl_Token** tokenPtrPtr,	/* INPUT/OUTPUT: Pointer to the token holding
				 * the operand */
    Tcl_Obj** operandObjPtr)	/* OUTPUT: Tcl object holding the operand text
				 * with \-substitutions done. */
{
    Tcl_Interp* interp = (Tcl_Interp*) assemEnvPtr->envPtr->iPtr;
    Tcl_Obj* operandObj = Tcl_NewObj();

    if (!TclWordKnownAtCompileTime(*tokenPtrPtr, operandObj)) {
	Tcl_DecrRefCount(operandObj);
	if (assemEnvPtr->flags & TCL_EVAL_DIRECT) {
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "assembly code may not contain substitutions", -1));
	    Tcl_SetErrorCode(interp, "TCL", "ASSEM", "NOSUBST", NULL);
	}
	return TCL_ERROR;
    }
    *tokenPtrPtr = TokenAfter(*tokenPtrPtr);
    Tcl_IncrRefCount(operandObj);
    *operandObjPtr = operandObj;
    return TCL_OK;
}

/*
 *-----------------------------------------------------------------------------
 *
 * GetBooleanOperand --
 *
 *	Retrieves a Boolean operand from the input stream and advances
 *	the token pointer.
 *
 * Results:
 *	Returns a standard Tcl result (with an error message in the
 *	interpreter on failure).
 *
 * Side effects:
 *	Stores the Boolean value in (*result) and advances (*tokenPtrPtr)
 *	to the next token.
 *
 *-----------------------------------------------------------------------------
 */

static int
GetBooleanOperand(
    AssemblyEnv* assemEnvPtr,	/* Assembly environment */
    Tcl_Token** tokenPtrPtr,	/* Current token from the parser */
    int* result)		/* OUTPUT: Integer extracted from the token */
{
    CompileEnv* envPtr = assemEnvPtr->envPtr;
				/* Compilation environment */
    Tcl_Interp* interp = (Tcl_Interp*) envPtr->iPtr;
				/* Tcl interpreter */
    Tcl_Token* tokenPtr = *tokenPtrPtr;
				/* INOUT: Pointer to the next token in the
				 * source code */
    Tcl_Obj* intObj;		/* Integer from the source code */
    int status;			/* Tcl status return */

    /*
     * Extract the next token as a string.
     */

    if (GetNextOperand(assemEnvPtr, tokenPtrPtr, &intObj) != TCL_OK) {
	return TCL_ERROR;
    }

    /*
     * Convert to an integer, advance to the next token and return.
     */

    status = Tcl_GetBooleanFromObj(interp, intObj, result);
    Tcl_DecrRefCount(intObj);
    *tokenPtrPtr = TokenAfter(tokenPtr);
    return status;
}

/*
 *-----------------------------------------------------------------------------
 *
 * GetIntegerOperand --
 *
 *	Retrieves an integer operand from the input stream and advances the
 *	token pointer.
 *
 * Results:
 *	Returns a standard Tcl result (with an error message in the
 *	interpreter on failure).
 *
 * Side effects:
 *	Stores the integer value in (*result) and advances (*tokenPtrPtr) to
 *	the next token.
 *
 *-----------------------------------------------------------------------------
 */

static int
GetIntegerOperand(
    AssemblyEnv* assemEnvPtr,	/* Assembly environment */
    Tcl_Token** tokenPtrPtr,	/* Current token from the parser */
    int* result)		/* OUTPUT: Integer extracted from the token */
{
    CompileEnv* envPtr = assemEnvPtr->envPtr;
				/* Compilation environment */
    Tcl_Interp* interp = (Tcl_Interp*) envPtr->iPtr;
				/* Tcl interpreter */
    Tcl_Token* tokenPtr = *tokenPtrPtr;
				/* INOUT: Pointer to the next token in the
				 * source code */
    Tcl_Obj* intObj;		/* Integer from the source code */
    int status;			/* Tcl status return */

    /*
     * Extract the next token as a string.
     */

    if (GetNextOperand(assemEnvPtr, tokenPtrPtr, &intObj) != TCL_OK) {
	return TCL_ERROR;
    }

    /*
     * Convert to an integer, advance to the next token and return.
     */

    status = Tcl_GetIntFromObj(interp, intObj, result);
    Tcl_DecrRefCount(intObj);
    *tokenPtrPtr = TokenAfter(tokenPtr);
    return status;
}

/*
 *-----------------------------------------------------------------------------
 *
 * GetListIndexOperand --
 *
 *	Gets the value of an operand intended to serve as a list index.
 *
 * Results:
 *	Returns a standard Tcl result: TCL_OK if the parse is successful and
 *	TCL_ERROR (with an appropriate error message) if the parse fails.
 *
 * Side effects:
 *	Stores the list index at '*index'. Values between -1 and 0x7fffffff
 *	have their natural meaning; values between -2 and -0x80000000
 *	represent 'end-2-N'.
 *
 *-----------------------------------------------------------------------------
 */

static int
GetListIndexOperand(
    AssemblyEnv* assemEnvPtr,	/* Assembly environment */
    Tcl_Token** tokenPtrPtr,	/* Current token from the parser */
    int* result)		/* OUTPUT: Integer extracted from the token */
{
    CompileEnv* envPtr = assemEnvPtr->envPtr;
				/* Compilation environment */
    Tcl_Interp* interp = (Tcl_Interp*) envPtr->iPtr;
				/* Tcl interpreter */
    Tcl_Token* tokenPtr = *tokenPtrPtr;
				/* INOUT: Pointer to the next token in the
				 * source code */
    Tcl_Obj* intObj;		/* Integer from the source code */
    int status;			/* Tcl status return */

    /*
     * Extract the next token as a string.
     */

    if (GetNextOperand(assemEnvPtr, tokenPtrPtr, &intObj) != TCL_OK) {
	return TCL_ERROR;
    }

    /*
     * Convert to an integer, advance to the next token and return.
     */

    status = TclGetIntForIndex(interp, intObj, -2, result);
    Tcl_DecrRefCount(intObj);
    *tokenPtrPtr = TokenAfter(tokenPtr);
    return status;
}

/*
 *-----------------------------------------------------------------------------
 *
 * FindLocalVar --
 *
 *	Gets the name of a local variable from the input stream and advances
 *	the token pointer.
 *
 * Results:
 *	Returns the LVT index of the local variable.  Returns -1 if the
 *	variable is non-local, not known at compile time, or cannot be
 *	installed in the LVT (leaving an error message in the interpreter
 *	result if necessary).
 *
 * Side effects:
 *	Advances the token pointer.  May define a new LVT slot if the variable
 *	has not yet been seen and the execution context allows for it.
 *
 *-----------------------------------------------------------------------------
 */

static int
FindLocalVar(
    AssemblyEnv* assemEnvPtr,	/* Assembly environment */
    Tcl_Token** tokenPtrPtr)
{
    CompileEnv* envPtr = assemEnvPtr->envPtr;
				/* Compilation environment */
    Tcl_Interp* interp = (Tcl_Interp*) envPtr->iPtr;
				/* Tcl interpreter */
    Tcl_Token* tokenPtr = *tokenPtrPtr;
				/* INOUT: Pointer to the next token in the
				 * source code. */
    Tcl_Obj* varNameObj;	/* Name of the variable */
    const char* varNameStr;
    int varNameLen;
    int localVar;		/* Index of the variable in the LVT */

    if (GetNextOperand(assemEnvPtr, tokenPtrPtr, &varNameObj) != TCL_OK) {
	return -1;
    }
2311
    varNameStr = TclGetStringFromObj(varNameObj, &varNameLen);
2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823
    if (CheckNamespaceQualifiers(interp, varNameStr, varNameLen)) {
	Tcl_DecrRefCount(varNameObj);
	return -1;
    }
    localVar = TclFindCompiledLocal(varNameStr, varNameLen, 1, envPtr);
    Tcl_DecrRefCount(varNameObj);
    if (localVar == -1) {
	if (assemEnvPtr->flags & TCL_EVAL_DIRECT) {
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "cannot use this instruction to create a variable"
		    " in a non-proc context", -1));
	    Tcl_SetErrorCode(interp, "TCL", "ASSEM", "LVT", NULL);
	}
	return -1;
    }
    *tokenPtrPtr = TokenAfter(tokenPtr);
    return localVar;
}

/*
 *-----------------------------------------------------------------------------
 *
 * CheckNamespaceQualifiers --
 *
 *	Verify that a variable name has no namespace qualifiers before
 *	attempting to install it in the LVT.
 *
 * Results:
 *	On success, returns TCL_OK. On failure, returns TCL_ERROR and stores
 *	an error message in the interpreter result.
 *
 *-----------------------------------------------------------------------------
 */

static int
CheckNamespaceQualifiers(
    Tcl_Interp* interp,		/* Tcl interpreter for error reporting */
    const char* name,		/* Variable name to check */
    int nameLen)		/* Length of the variable */
{
    const char* p;

    for (p = name; p+2 < name+nameLen;  p++) {
	if ((*p == ':') && (p[1] == ':')) {
	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		    "variable \"%s\" is not local", name));
	    Tcl_SetErrorCode(interp, "TCL", "ASSEM", "NONLOCAL", name, NULL);
	    return TCL_ERROR;
	}
    }
    return TCL_OK;
}

/*
 *-----------------------------------------------------------------------------
 *
 * CheckOneByte --
 *
 *	Verify that a constant fits in a single byte in the instruction
 *	stream.
 *
 * Results:
 *	On success, returns TCL_OK. On failure, returns TCL_ERROR and stores
 *	an error message in the interpreter result.
 *
 * This code is here primarily to verify that instructions like INCR_SCALAR1
 * are possible on a given local variable. The fact that there is no
 * INCR_SCALAR4 is puzzling.
 *
 *-----------------------------------------------------------------------------
 */

static int
CheckOneByte(
    Tcl_Interp* interp,		/* Tcl interpreter for error reporting */
    int value)			/* Value to check */
{
    Tcl_Obj* result;		/* Error message */

    if (value < 0 || value > 0xff) {
	result = Tcl_NewStringObj("operand does not fit in one byte", -1);
	Tcl_SetObjResult(interp, result);
	Tcl_SetErrorCode(interp, "TCL", "ASSEM", "1BYTE", NULL);
	return TCL_ERROR;
    }
    return TCL_OK;
}

/*
 *-----------------------------------------------------------------------------
 *
 * CheckSignedOneByte --
 *
 *	Verify that a constant fits in a single signed byte in the instruction
 *	stream.
 *
 * Results:
 *	On success, returns TCL_OK. On failure, returns TCL_ERROR and stores
 *	an error message in the interpreter result.
 *
 * This code is here primarily to verify that instructions like INCR_SCALAR1
 * are possible on a given local variable. The fact that there is no
 * INCR_SCALAR4 is puzzling.
 *
 *-----------------------------------------------------------------------------
 */

static int
CheckSignedOneByte(
    Tcl_Interp* interp,		/* Tcl interpreter for error reporting */
    int value)			/* Value to check */
{
    Tcl_Obj* result;		/* Error message */

    if (value > 0x7f || value < -0x80) {
	result = Tcl_NewStringObj("operand does not fit in one byte", -1);
	Tcl_SetObjResult(interp, result);
	Tcl_SetErrorCode(interp, "TCL", "ASSEM", "1BYTE", NULL);
	return TCL_ERROR;
    }
    return TCL_OK;
}

/*
 *-----------------------------------------------------------------------------
 *
 * CheckNonNegative --
 *
 *	Verify that a constant is nonnegative
 *
 * Results:
 *	On success, returns TCL_OK. On failure, returns TCL_ERROR and stores
 *	an error message in the interpreter result.
 *
 * This code is here primarily to verify that instructions like INCR_INVOKE
 * are consuming a positive number of operands
 *
 *-----------------------------------------------------------------------------
 */

static int
CheckNonNegative(
    Tcl_Interp* interp,		/* Tcl interpreter for error reporting */
    int value)			/* Value to check */
{
    Tcl_Obj* result;		/* Error message */

    if (value < 0) {
	result = Tcl_NewStringObj("operand must be nonnegative", -1);
	Tcl_SetObjResult(interp, result);
	Tcl_SetErrorCode(interp, "TCL", "ASSEM", "NONNEGATIVE", NULL);
	return TCL_ERROR;
    }
    return TCL_OK;
}

/*
 *-----------------------------------------------------------------------------
 *
 * CheckStrictlyPositive --
 *
 *	Verify that a constant is positive
 *
 * Results:
 *	On success, returns TCL_OK. On failure, returns TCL_ERROR and
 *	stores an error message in the interpreter result.
 *
 * This code is here primarily to verify that instructions like INCR_INVOKE
 * are consuming a positive number of operands
 *
 *-----------------------------------------------------------------------------
 */

static int
CheckStrictlyPositive(
    Tcl_Interp* interp,		/* Tcl interpreter for error reporting */
    int value)			/* Value to check */
{
    Tcl_Obj* result;		/* Error message */

    if (value <= 0) {
	result = Tcl_NewStringObj("operand must be positive", -1);
	Tcl_SetObjResult(interp, result);
	Tcl_SetErrorCode(interp, "TCL", "ASSEM", "POSITIVE", NULL);
	return TCL_ERROR;
    }
    return TCL_OK;
}

/*
 *-----------------------------------------------------------------------------
 *
 * DefineLabel --
 *
 *	Defines a label appearing in the assembly sequence.
 *
 * Results:
 *	Returns a standard Tcl result. Returns TCL_OK and an empty result if
 *	the definition succeeds; returns TCL_ERROR and an appropriate message
 *	if a duplicate definition is found.
 *
 *-----------------------------------------------------------------------------
 */

static int
DefineLabel(
    AssemblyEnv* assemEnvPtr,	/* Assembly environment */
    const char* labelName)	/* Label being defined */
{
    CompileEnv* envPtr = assemEnvPtr->envPtr;
				/* Compilation environment */
    Tcl_Interp* interp = (Tcl_Interp*) envPtr->iPtr;
				/* Tcl interpreter */
    Tcl_HashEntry* entry;	/* Label's entry in the symbol table */
    int isNew;			/* Flag == 1 iff the label was previously
				 * undefined */

    /* TODO - This can now be simplified! */

    StartBasicBlock(assemEnvPtr, BB_FALLTHRU, NULL);

    /*
     * Look up the newly-defined label in the symbol table.
     */

    entry = Tcl_CreateHashEntry(&assemEnvPtr->labelHash, labelName, &isNew);
    if (!isNew) {
	/*
	 * This is a duplicate label.
	 */

	if (assemEnvPtr->flags & TCL_EVAL_DIRECT) {
	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		    "duplicate definition of label \"%s\"", labelName));
	    Tcl_SetErrorCode(interp, "TCL", "ASSEM", "DUPLABEL", labelName,
		    NULL);
	}
	return TCL_ERROR;
    }

    /*
     * This is the first appearance of the label in the code.
     */

    Tcl_SetHashValue(entry, assemEnvPtr->curr_bb);
    return TCL_OK;
}

/*
 *-----------------------------------------------------------------------------
 *
 * StartBasicBlock --
 *
 *	Starts a new basic block when a label or jump is encountered.
 *
 * Results:
 *	Returns a pointer to the BasicBlock structure of the new
 *	basic block.
 *
 *-----------------------------------------------------------------------------
 */

static BasicBlock*
StartBasicBlock(
    AssemblyEnv* assemEnvPtr,	/* Assembly environment */
    int flags,			/* Flags to apply to the basic block being
				 * closed, if there is one. */
    Tcl_Obj* jumpLabel)		/* Label of the location that the block jumps
				 * to, or NULL if the block does not jump */
{
    CompileEnv* envPtr = assemEnvPtr->envPtr;
				/* Compilation environment */
    BasicBlock* newBB;		/* BasicBlock structure for the new block */
    BasicBlock* currBB = assemEnvPtr->curr_bb;

    /*
     * Coalesce zero-length blocks.
     */

    if (currBB->startOffset == envPtr->codeNext - envPtr->codeStart) {
	currBB->startLine = assemEnvPtr->cmdLine;
	return currBB;
    }

    /*
     * Make the new basic block.
     */

    newBB = AllocBB(assemEnvPtr);

    /*
     * Record the jump target if there is one.
     */

    currBB->jumpTarget = jumpLabel;
    if (jumpLabel != NULL) {
	Tcl_IncrRefCount(currBB->jumpTarget);
    }

    /*
     * Record the fallthrough if there is one.
     */

    currBB->flags |= flags;

    /*
     * Record the successor block.
     */

    currBB->successor1 = newBB;
    assemEnvPtr->curr_bb = newBB;
    return newBB;
}

/*
 *-----------------------------------------------------------------------------
 *
 * AllocBB --
 *
 *	Allocates a new basic block
 *
 * Results:
 *	Returns a pointer to the newly allocated block, which is initialized
 *	to contain no code and begin at the current instruction pointer.
 *
 *-----------------------------------------------------------------------------
 */

static BasicBlock *
AllocBB(
    AssemblyEnv* assemEnvPtr)	/* Assembly environment */
{
    CompileEnv* envPtr = assemEnvPtr->envPtr;
    BasicBlock *bb = ckalloc(sizeof(BasicBlock));

    bb->originalStartOffset =
	    bb->startOffset = envPtr->codeNext - envPtr->codeStart;
    bb->startLine = assemEnvPtr->cmdLine + 1;
    bb->jumpOffset = -1;
    bb->jumpLine = -1;
    bb->prevPtr = assemEnvPtr->curr_bb;
    bb->predecessor = NULL;
    bb->successor1 = NULL;
    bb->jumpTarget = NULL;
    bb->initialStackDepth = 0;
    bb->minStackDepth = 0;
    bb->maxStackDepth = 0;
    bb->finalStackDepth = 0;
    bb->catchDepth = 0;
    bb->enclosingCatch = NULL;
    bb->foreignExceptionBase = -1;
    bb->foreignExceptionCount = 0;
    bb->foreignExceptions = NULL;
    bb->jtPtr = NULL;
    bb->flags = 0;

    return bb;
}

/*
 *-----------------------------------------------------------------------------
 *
 * FinishAssembly --
 *
 *	Postprocessing after all bytecode has been generated for a block of
 *	assembly code.
 *
 * Results:
 *	Returns a standard Tcl result, with an error message left in the
 *	interpreter if appropriate.
 *
 * Side effects:
 *	The program is checked to see if any undefined labels remain.  The
 *	initial stack depth of all the basic blocks in the flow graph is
 *	calculated and saved.  The stack balance on exit is computed, checked
 *	and saved.
 *
 *-----------------------------------------------------------------------------
 */

static int
FinishAssembly(
    AssemblyEnv* assemEnvPtr)	/* Assembly environment */
{
    int mustMove;		/* Amount by which the code needs to be grown
				 * because of expanding jumps */

    /*
     * Resolve the targets of all jumps and determine whether code needs to be
     * moved around.
     */

    if (CalculateJumpRelocations(assemEnvPtr, &mustMove)) {
	return TCL_ERROR;
    }

    /*
     * Move the code if necessary.
     */

    if (mustMove) {
	MoveCodeForJumps(assemEnvPtr, mustMove);
    }

    /*
     * Resolve jump target labels to bytecode offsets.
     */

    FillInJumpOffsets(assemEnvPtr);

    /*
     * Label each basic block with its catch context. Quit on inconsistency.
     */

    if (ProcessCatches(assemEnvPtr) != TCL_OK) {
	return TCL_ERROR;
    }

    /*
     * Make sure that no block accessible from a catch's error exit that hasn't
     * popped the exception stack can throw an exception.
     */

    if (CheckForThrowInWrongContext(assemEnvPtr) != TCL_OK) {
	return TCL_ERROR;
    }

    /*
     * Compute stack balance throughout the program.
     */

    if (CheckStack(assemEnvPtr) != TCL_OK) {
	return TCL_ERROR;
    }

    /*
     * TODO - Check for unreachable code. Or maybe not; unreachable code is
     * Mostly Harmless.
     */

    return TCL_OK;
}

/*
 *-----------------------------------------------------------------------------
 *
 * CalculateJumpRelocations --
 *
 *	Calculate any movement that has to be done in the assembly code to
 *	expand JUMP1 instructions to JUMP4 (because they jump more than a
 *	1-byte range).
 *
 * Results:
 *	Returns a standard Tcl result, with an appropriate error message if
 *	anything fails.
 *
 * Side effects:
 *	Sets the 'startOffset' pointer in every basic block to the new origin
 *	of the block, and turns off JUMP1 flags on instructions that must be
 *	expanded (and adjusts them to the corresponding JUMP4's).  Does *not*
 *	store the jump offsets at this point.
 *
 *	Sets *mustMove to 1 if and only if at least one instruction changed
 *	size so the code must be moved.
 *
 *	As a side effect, also checks for undefined labels and reports them.
 *
 *-----------------------------------------------------------------------------
 */

static int
CalculateJumpRelocations(
    AssemblyEnv* assemEnvPtr,	/* Assembly environment */
    int* mustMove)		/* OUTPUT: Number of bytes that have been
				 * added to the code */
{
    CompileEnv* envPtr = assemEnvPtr->envPtr;
				/* Compilation environment */
    BasicBlock* bbPtr;		/* Pointer to a basic block being checked */
    Tcl_HashEntry* entry;	/* Exit label's entry in the symbol table */
    BasicBlock* jumpTarget;	/* Basic block where the jump goes */
    int motion;			/* Amount by which the code has expanded */
    int offset;			/* Offset in the bytecode from a jump
				 * instruction to its target */
    unsigned opcode;		/* Opcode in the bytecode being adjusted */

    /*
     * Iterate through basic blocks as long as a change results in code
     * expansion.
     */

    *mustMove = 0;
    do {
	motion = 0;
	for (bbPtr = assemEnvPtr->head_bb;
		bbPtr != NULL;
		bbPtr = bbPtr->successor1) {
	    /*
	     * Advance the basic block start offset by however many bytes we
	     * have inserted in the code up to this point
	     */

	    bbPtr->startOffset += motion;

	    /*
	     * If the basic block references a label (and hence performs a
	     * jump), find the location of the label. Report an error if the
	     * label is missing.
	     */

	    if (bbPtr->jumpTarget != NULL) {
		entry = Tcl_FindHashEntry(&assemEnvPtr->labelHash,
2824
			TclGetString(bbPtr->jumpTarget));
2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904
		if (entry == NULL) {
		    ReportUndefinedLabel(assemEnvPtr, bbPtr,
			    bbPtr->jumpTarget);
		    return TCL_ERROR;
		}

		/*
		 * If the instruction is a JUMP1, turn it into a JUMP4 if its
		 * target is out of range.
		 */

		jumpTarget = Tcl_GetHashValue(entry);
		if (bbPtr->flags & BB_JUMP1) {
		    offset = jumpTarget->startOffset
			    - (bbPtr->jumpOffset + motion);
		    if (offset < -0x80 || offset > 0x7f) {
			opcode = TclGetUInt1AtPtr(envPtr->codeStart
				+ bbPtr->jumpOffset);
			++opcode;
			TclStoreInt1AtPtr(opcode,
				envPtr->codeStart + bbPtr->jumpOffset);
			motion += 3;
			bbPtr->flags &= ~BB_JUMP1;
		    }
		}
	    }

	    /*
	     * If the basic block references a jump table, that doesn't affect
	     * the code locations, but resolve the labels now, and store basic
	     * block pointers in the jumptable hash.
	     */

	    if (bbPtr->flags & BB_JUMPTABLE) {
		if (CheckJumpTableLabels(assemEnvPtr, bbPtr) != TCL_OK) {
		    return TCL_ERROR;
		}
	    }
	}
	*mustMove += motion;
    } while (motion != 0);

    return TCL_OK;
}

/*
 *-----------------------------------------------------------------------------
 *
 * CheckJumpTableLabels --
 *
 *	Make sure that all the labels in a jump table are defined.
 *
 * Results:
 *	Returns TCL_OK if they are, TCL_ERROR if they aren't.
 *
 *-----------------------------------------------------------------------------
 */

static int
CheckJumpTableLabels(
    AssemblyEnv* assemEnvPtr,	/* Assembly environment */
    BasicBlock* bbPtr)		/* Basic block that ends in a jump table */
{
    Tcl_HashTable* symHash = &bbPtr->jtPtr->hashTable;
				/* Hash table with the symbols */
    Tcl_HashSearch search;	/* Hash table iterator */
    Tcl_HashEntry* symEntryPtr;	/* Hash entry for the symbols */
    Tcl_Obj* symbolObj;		/* Jump target */
    Tcl_HashEntry* valEntryPtr;	/* Hash entry for the resolutions */

    /*
     * Look up every jump target in the jump hash.
     */

    DEBUG_PRINT("check jump table labels %p {\n", bbPtr);
    for (symEntryPtr = Tcl_FirstHashEntry(symHash, &search);
	    symEntryPtr != NULL;
	    symEntryPtr = Tcl_NextHashEntry(&search)) {
	symbolObj = Tcl_GetHashValue(symEntryPtr);
	valEntryPtr = Tcl_FindHashEntry(&assemEnvPtr->labelHash,
2905
		TclGetString(symbolObj));
2906 2907
	DEBUG_PRINT("  %s -> %s (%d)\n",
		(char*) Tcl_GetHashKey(symHash, symEntryPtr),
2908
		TclGetString(symbolObj), (valEntryPtr != NULL));
2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945
	if (valEntryPtr == NULL) {
	    ReportUndefinedLabel(assemEnvPtr, bbPtr, symbolObj);
	    return TCL_ERROR;
	}
    }
    DEBUG_PRINT("}\n");
    return TCL_OK;
}

/*
 *-----------------------------------------------------------------------------
 *
 * ReportUndefinedLabel --
 *
 *	Report that a basic block refers to an undefined jump label
 *
 * Side effects:
 *	Stores an error message, error code, and line number information in
 *	the assembler's Tcl interpreter.
 *
 *-----------------------------------------------------------------------------
 */

static void
ReportUndefinedLabel(
    AssemblyEnv* assemEnvPtr,	/* Assembly environment */
    BasicBlock* bbPtr,		/* Basic block that contains the undefined
				 * label */
    Tcl_Obj* jumpTarget)	/* Label of a jump target */
{
    CompileEnv* envPtr = assemEnvPtr->envPtr;
				/* Compilation environment */
    Tcl_Interp* interp = (Tcl_Interp*) envPtr->iPtr;
				/* Tcl interpreter */

    if (assemEnvPtr->flags & TCL_EVAL_DIRECT) {
	Tcl_SetObjResult(interp, Tcl_ObjPrintf(
2946
		"undefined label \"%s\"", TclGetString(jumpTarget)));
2947
	Tcl_SetErrorCode(interp, "TCL", "ASSEM", "NOLABEL",
2948
		TclGetString(jumpTarget), NULL);
2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030
	Tcl_SetErrorLine(interp, bbPtr->jumpLine);
    }
}

/*
 *-----------------------------------------------------------------------------
 *
 * MoveCodeForJumps --
 *
 *	Move bytecodes in memory to accommodate JUMP1 instructions that have
 *	expanded to become JUMP4's.
 *
 *-----------------------------------------------------------------------------
 */

static void
MoveCodeForJumps(
    AssemblyEnv* assemEnvPtr,	/* Assembler environment */
    int mustMove)		/* Number of bytes of added code */
{
    CompileEnv* envPtr = assemEnvPtr->envPtr;
				/* Compilation environment */
    BasicBlock* bbPtr;		/* Pointer to a basic block being checked */
    int topOffset;		/* Bytecode offset of the following basic
				 * block before code motion */

    /*
     * Make sure that there is enough space in the bytecode array to
     * accommodate the expanded code.
     */

    while (envPtr->codeEnd < envPtr->codeNext + mustMove) {
	TclExpandCodeArray(envPtr);
    }

    /*
     * Iterate through the bytecodes in reverse order, and move them upward to
     * their new homes.
     */

    topOffset = envPtr->codeNext - envPtr->codeStart;
    for (bbPtr = assemEnvPtr->curr_bb; bbPtr != NULL; bbPtr = bbPtr->prevPtr) {
	DEBUG_PRINT("move code from %d to %d\n",
		bbPtr->originalStartOffset, bbPtr->startOffset);
	memmove(envPtr->codeStart + bbPtr->startOffset,
		envPtr->codeStart + bbPtr->originalStartOffset,
		topOffset - bbPtr->originalStartOffset);
	topOffset = bbPtr->originalStartOffset;
	bbPtr->jumpOffset += (bbPtr->startOffset - bbPtr->originalStartOffset);
    }
    envPtr->codeNext += mustMove;
}

/*
 *-----------------------------------------------------------------------------
 *
 * FillInJumpOffsets --
 *
 *	Fill in the final offsets of all jump instructions once bytecode
 *	locations have been completely determined.
 *
 *-----------------------------------------------------------------------------
 */

static void
FillInJumpOffsets(
    AssemblyEnv* assemEnvPtr)	/* Assembly environment */
{
    CompileEnv* envPtr = assemEnvPtr->envPtr;
				/* Compilation environment */
    BasicBlock* bbPtr;		/* Pointer to a basic block being checked */
    Tcl_HashEntry* entry;	/* Hashtable entry for a jump target label */
    BasicBlock* jumpTarget;	/* Basic block where a jump goes */
    int fromOffset;		/* Bytecode location of a jump instruction */
    int targetOffset;		/* Bytecode location of a jump instruction's
				 * target */

    for (bbPtr = assemEnvPtr->head_bb;
	    bbPtr != NULL;
	    bbPtr = bbPtr->successor1) {
	if (bbPtr->jumpTarget != NULL) {
	    entry = Tcl_FindHashEntry(&assemEnvPtr->labelHash,
3031
		    TclGetString(bbPtr->jumpTarget));
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	    jumpTarget = Tcl_GetHashValue(entry);
	    fromOffset = bbPtr->jumpOffset;
	    targetOffset = jumpTarget->startOffset;
	    if (bbPtr->flags & BB_JUMP1) {
		TclStoreInt1AtPtr(targetOffset - fromOffset,
			envPtr->codeStart + fromOffset + 1);
	    } else {
		TclStoreInt4AtPtr(targetOffset - fromOffset,
			envPtr->codeStart + fromOffset + 1);
	    }
	}
	if (bbPtr->flags & BB_JUMPTABLE) {
	    ResolveJumpTableTargets(assemEnvPtr, bbPtr);
	}
    }
}

/*
 *-----------------------------------------------------------------------------
 *
 * ResolveJumpTableTargets --
 *
 *	Puts bytecode addresses for the targets of a jumptable into the
 *	table
 *
 * Results:
 *	Returns TCL_OK if they are, TCL_ERROR if they aren't.
 *
 *-----------------------------------------------------------------------------
 */

static void
ResolveJumpTableTargets(
    AssemblyEnv* assemEnvPtr,	/* Assembly environment */
    BasicBlock* bbPtr)		/* Basic block that ends in a jump table */
{
    CompileEnv* envPtr = assemEnvPtr->envPtr;
				/* Compilation environment */
    Tcl_HashTable* symHash = &bbPtr->jtPtr->hashTable;
				/* Hash table with the symbols */
    Tcl_HashSearch search;	/* Hash table iterator */
    Tcl_HashEntry* symEntryPtr;	/* Hash entry for the symbols */
    Tcl_Obj* symbolObj;		/* Jump target */
    Tcl_HashEntry* valEntryPtr;	/* Hash entry for the resolutions */
    int auxDataIndex;		/* Index of the auxdata */
    JumptableInfo* realJumpTablePtr;
				/* Jump table in the actual code */
    Tcl_HashTable* realJumpHashPtr;
				/* Jump table hash in the actual code */
    Tcl_HashEntry* realJumpEntryPtr;
				/* Entry in the jump table hash in
				 * the actual code */
    BasicBlock* jumpTargetBBPtr;
				/* Basic block that the jump proceeds to */
    int junk;

    auxDataIndex = TclGetInt4AtPtr(envPtr->codeStart + bbPtr->jumpOffset + 1);
    DEBUG_PRINT("bbPtr = %p jumpOffset = %d auxDataIndex = %d\n",
	    bbPtr, bbPtr->jumpOffset, auxDataIndex);
    realJumpTablePtr = TclFetchAuxData(envPtr, auxDataIndex);
    realJumpHashPtr = &realJumpTablePtr->hashTable;

    /*
     * Look up every jump target in the jump hash.
     */

    DEBUG_PRINT("resolve jump table {\n");
    for (symEntryPtr = Tcl_FirstHashEntry(symHash, &search);
	    symEntryPtr != NULL;
	    symEntryPtr = Tcl_NextHashEntry(&search)) {
	symbolObj = Tcl_GetHashValue(symEntryPtr);
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	DEBUG_PRINT("     symbol %s\n", TclGetString(symbolObj));
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	valEntryPtr = Tcl_FindHashEntry(&assemEnvPtr->labelHash,
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		TclGetString(symbolObj));
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	jumpTargetBBPtr = Tcl_GetHashValue(valEntryPtr);

	realJumpEntryPtr = Tcl_CreateHashEntry(realJumpHashPtr,
		Tcl_GetHashKey(symHash, symEntryPtr), &junk);
	DEBUG_PRINT("  %s -> %s -> bb %p (pc %d)    hash entry %p\n",
		(char*) Tcl_GetHashKey(symHash, symEntryPtr),
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		TclGetString(symbolObj), jumpTargetBBPtr,
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