interpret.c

nedit 是一款linux下的开发源码的功能强大的编辑器

static const char CVSID[] = "$Id: interpret.c,v 1.33.2.1 2003/10/20 16:38:57 tringali Exp $";
/*******************************************************************************
*									       *
* interpret.c -- Nirvana Editor macro interpreter			       *
*									       *
* Copyright (C) 1999 Mark Edel						       *
*									       *
* This is free software; you can redistribute it and/or modify it under the    *
* terms of the GNU General Public License as published by the Free Software    *
* Foundation; either version 2 of the License, or (at your option) any later   *
* version.							               *
* 									       *
* This software is distributed in the hope that it will be useful, but WITHOUT *
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or        *
* FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License        *
* for more details.							       *
* 									       *
* You should have received a copy of the GNU General Public License along with *
* software; if not, write to the Free Software Foundation, Inc., 59 Temple     *
* Place, Suite 330, Boston, MA  02111-1307 USA		                       *
*									       *
* Nirvana Text Editor	    						       *
* April, 1997								       *
*									       *
* Written by Mark Edel							       *
*									       *
*******************************************************************************/

#ifdef HAVE_CONFIG_H
#include "../config.h"
#endif

#include "interpret.h"
#include "textBuf.h"
#include "nedit.h"
#include "menu.h"
#include "text.h"
#include "rbTree.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <limits.h>
#include <ctype.h>
#include <errno.h>
#ifdef VMS
#include "../util/VMSparam.h"
#else
#ifndef __MVS__
#include <sys/param.h>
#endif
#endif /*VMS*/

#include <X11/Intrinsic.h>
#include <Xm/Xm.h>

#ifdef HAVE_DEBUG_H
#include "../debug.h"
#endif

#define PROGRAM_SIZE  4096	/* Maximum program size */
#define MAX_ERR_MSG_LEN 256	/* Max. length for error messages */
#define LOOP_STACK_SIZE 200	/* (Approx.) Number of break/continue stmts
    	    	    	    	   allowed per program */
#define INSTRUCTION_LIMIT 100 	/* Number of instructions the interpreter is
    	    	    	    	   allowed to execute before preempting and
    	    	    	    	   returning to allow other things to run */

/* Temporary markers placed in a branch address location to designate
   which loop address (break or continue) the location needs */
#define NEEDS_BREAK (Inst)1
#define NEEDS_CONTINUE (Inst)2

#define N_ARGS_ARG_SYM -1   	/* special arg number meaning $n_args value */

enum opStatusCodes {STAT_OK=2, STAT_DONE, STAT_ERROR, STAT_PREEMPT};

static void addLoopAddr(Inst *addr);
static void saveContext(RestartData *context);
static void restoreContext(RestartData *context);
static int returnNoVal(void);
static int returnVal(void);
static int returnValOrNone(int valOnStack);
static int pushSymVal(void);
static int pushArraySymVal(void);
static int dupStack(void);
static int add(void);
static int subtract(void);
static int multiply(void);
static int divide(void);
static int modulo(void);
static int negate(void);
static int increment(void);
static int decrement(void);
static int gt(void);
static int lt(void);
static int ge(void);
static int le(void);
static int eq(void);
static int ne(void);
static int bitAnd(void);
static int bitOr(void);
static int and(void);
static int or(void);
static int not(void);
static int power(void);
static int concat(void);
static int assign(void);
static int callSubroutine(void);
static int fetchRetVal(void);
static int branch(void);
static int branchTrue(void);
static int branchFalse(void);
static int branchNever(void);
static int arrayRef(void);
static int arrayAssign(void);
static int arrayRefAndAssignSetup(void);
static int beginArrayIter(void);
static int arrayIter(void);
static int inArray(void);
static int deleteArrayElement(void);
static void freeSymbolTable(Symbol *symTab);
static int errCheck(const char *s);
static int execError(const char *s1, const char *s2);
static rbTreeNode *arrayEmptyAllocator(void);
static rbTreeNode *arrayAllocateNode(rbTreeNode *src);
static int arrayEntryCopyToNode(rbTreeNode *dst, rbTreeNode *src);
static int arrayEntryCompare(rbTreeNode *left, rbTreeNode *right);
static void arrayDisposeNode(rbTreeNode *src);
static SparseArrayEntry *allocateSparseArrayEntry(void);

/*#define DEBUG_ASSEMBLY*/
/*#define DEBUG_STACK*/

#if defined(DEBUG_ASSEMBLY) || defined(DEBUG_STACK)
#define DEBUG_DISASSEMBLER
static void disasm(Inst *inst, int nInstr);
#endif /* #if defined(DEBUG_ASSEMBLY) || defined(DEBUG_STACK) */

#ifdef DEBUG_ASSEMBLY   /* for disassembly */
#define DISASM(i, n)    disasm(i, n)
#else /* #ifndef DEBUG_ASSEMBLY */
#define DISASM(i, n)
#endif /* #ifndef DEBUG_ASSEMBLY */

#ifdef DEBUG_STACK      /* for run-time instruction and stack trace */
static void stackdump(int n, int extra);
#define STACKDUMP(n, x) stackdump(n, x)
#define DISASM_RT(i, n) disasm(i, n)
#else /* #ifndef DEBUG_STACK */
#define STACKDUMP(n, x)
#define DISASM_RT(i, n)
#endif /* #ifndef DEBUG_STACK */

/* Global symbols and function definitions */
static Symbol *GlobalSymList = NULL;

/* List of all memory allocated for strings */
static char *AllocatedStrings = NULL;

typedef struct {
    SparseArrayEntry 	data; /* LEAVE this as top entry */
    int inUse;              /* we use pointers to the data to refer to the entire struct */
    struct SparseArrayEntryWrapper *next;
} SparseArrayEntryWrapper;

static SparseArrayEntryWrapper *AllocatedSparseArrayEntries = NULL; 

/* Message strings used in macros (so they don't get repeated every time
   the macros are used */
static const char *StackOverflowMsg = "macro stack overflow";
static const char *StackUnderflowMsg = "macro stack underflow";
static const char *StringToNumberMsg = "string could not be converted to number";

/* Temporary global data for use while accumulating programs */
static Symbol *LocalSymList = NULL;	 /* symbols local to the program */
static Inst Prog[PROGRAM_SIZE]; 	 /* the program */
static Inst *ProgP;			 /* next free spot for code gen. */
static Inst *LoopStack[LOOP_STACK_SIZE]; /* addresses of break, cont stmts */
static Inst **LoopStackPtr = LoopStack;  /*  to fill at the end of a loop */

/* Global data for the interpreter */
static DataValue *Stack;	    /* the stack */
static DataValue *StackP;	    /* next free spot on stack */
static DataValue *FrameP;   	    /* frame pointer (start of local variables
    	    	    	    	       for the current subroutine invocation) */
static Inst *PC;		    /* program counter during execution */
static char *ErrMsg;		    /* global for returning error messages
    	    	    	    	       from executing functions */
static WindowInfo
	*InitiatingWindow = NULL;   /* window from which macro was run */
static WindowInfo *FocusWindow;	    /* window on which macro commands operate */
static int PreemptRequest;  	    /* passes preemption requests from called
    	    	    	    	       routines back up to the interpreter */

/* Array for mapping operations to functions for performing the operations
   Must correspond to the enum called "operations" in interpret.h */
static int (*OpFns[N_OPS])() = {returnNoVal, returnVal, pushSymVal, dupStack,
    add, subtract, multiply, divide, modulo, negate, increment, decrement,
    gt, lt, ge, le, eq, ne, bitAnd, bitOr, and, or, not, power, concat,
    assign, callSubroutine, fetchRetVal, branch, branchTrue, branchFalse,
    branchNever, arrayRef, arrayAssign, beginArrayIter, arrayIter, inArray,
    deleteArrayElement, pushArraySymVal,
    arrayRefAndAssignSetup};

/*
** Initialize macro language global variables.  Must be called before
** any macros are even parsed, because the parser uses action routine
** symbols to comprehend hyphenated names.
*/
void InitMacroGlobals(void)
{
    XtActionsRec *actions;
    int i, nActions;
    static char argName[3] = "$x";
    static DataValue dv = {NO_TAG, {0}};

    /* Add action routines from NEdit menus and text widget */
    actions = GetMenuActions(&nActions);
    for (i=0; i<nActions; i++) {
    	dv.val.xtproc = actions[i].proc;
    	InstallSymbol(actions[i].string, ACTION_ROUTINE_SYM, dv);
    }
    actions = TextGetActions(&nActions);
    for (i=0; i<nActions; i++) {
    	dv.val.xtproc = actions[i].proc;
    	InstallSymbol(actions[i].string, ACTION_ROUTINE_SYM, dv);
    }
    
    /* Add subroutine argument symbols ($1, $2, ..., $9) */
    for (i=0; i<9; i++) {
	argName[1] = '1' + i;
	dv.val.n = i;
	InstallSymbol(argName, ARG_SYM, dv);
    }
    
    /* Add special symbol $n_args */
    dv.val.n = N_ARGS_ARG_SYM;
    InstallSymbol("$n_args", ARG_SYM, dv);
}

/*
** To build a program for the interpreter, call BeginCreatingProgram, to
** begin accumulating the program, followed by calls to AddOp, AddSym,
** and InstallSymbol to add symbols and operations.  When the new program
** is finished, collect the results with FinishCreatingProgram.  This returns
** a self contained program that can be run with ExecuteMacro.
*/

/*
** Start collecting instructions for a program. Clears the program
** and the symbol table.
*/
void BeginCreatingProgram(void)
{ 
    LocalSymList = NULL;
    ProgP = Prog;
    LoopStackPtr = LoopStack;
}

/*
** Finish up the program under construction, and return it (code and
** symbol table) as a package that ExecuteMacro can execute.  This
** program must be freed with FreeProgram.
*/
Program *FinishCreatingProgram(void)
{
    Program *newProg;
    int progLen, fpOffset = 0;
    Symbol *s;
    
    newProg = (Program *)XtMalloc(sizeof(Program));
    progLen = ((char *)ProgP) - ((char *)Prog);
    newProg->code = (Inst *)XtMalloc(progLen);
    memcpy(newProg->code, Prog, progLen);
    newProg->localSymList = LocalSymList;
    LocalSymList = NULL;
    
    /* Local variables' values are stored on the stack.  Here we assign
       frame pointer offsets to them. */
    for (s = newProg->localSymList; s != NULL; s = s->next)
	s->value.val.n = fpOffset++;
    
    DISASM(newProg->code, ProgP - Prog);
    
    return newProg;
}

void FreeProgram(Program *prog)
{
    freeSymbolTable(prog->localSymList);
    XtFree((char *)prog->code);
    XtFree((char *)prog);    
}

/*
** Add an operator (instruction) to the end of the current program
*/
int AddOp(int op, char **msg)
{
    if (ProgP >= &Prog[PROGRAM_SIZE]) {
	*msg = "macro too large";
	return 0;
    }
    *ProgP++ = OpFns[op];
    return 1;
}

/*
** Add a symbol operand to the current program
*/
int AddSym(Symbol *sym, char **msg)
{
    if (ProgP >= &Prog[PROGRAM_SIZE]) {
	*msg = "macro too large";
	return 0;
    }
    *ProgP++ = (Inst)sym;
    return 1;
}

/*
** Add an immediate value operand to the current program
*/
int AddImmediate(void *value, char **msg)
{
    if (ProgP >= &Prog[PROGRAM_SIZE]) {
	*msg = "macro too large";
	return 0;
    }
    *ProgP++ = (Inst)value;
    return 1;
}

/*
** Add a branch offset operand to the current program
*/
int AddBranchOffset(Inst *to, char **msg)
{
    if (ProgP >= &Prog[PROGRAM_SIZE]) {
	*msg = "macro too large";
	return 0;
    }
    *ProgP = (Inst)(to - ProgP);
    ProgP++;
    
    return 1;
}

/*
** Return the address at which the next instruction will be stored
*/
Inst *GetPC(void)
{
    return ProgP;
}

/*
** Swap the positions of two contiguous blocks of code.  The first block
** running between locations start and boundary, and the second between
** boundary and end.
*/
void SwapCode(Inst *start, Inst *boundary, Inst *end)
{
#define reverseCode(L, H) \
    do { register Inst t, *l = L, *h = H - 1; \
         while (l < h) { t = *h; *h-- = *l; *l++ = t; } } while (0)
    /* double-reverse method: reverse elements of both parts then whole lot */
    /* eg abcdefABCD -1-> edcbaABCD -2-> edcbaDCBA -3-> DCBAedcba */
    reverseCode(start, boundary);   /* 1 */
    reverseCode(boundary, end);     /* 2 */
    reverseCode(start, end);        /* 3 */
}

/*
** Maintain a stack to save addresses of branch operations for break and
** continue statements, so they can be filled in once the information
** on where to branch is known.
**
** Call StartLoopAddrList at the beginning of a loop, AddBreakAddr or
** AddContinueAddr to register the address at which to store the branch
** address for a break or continue statement, and FillLoopAddrs to fill
** in all the addresses and return to the level of the enclosing loop.
*/
void StartLoopAddrList(void)
{
    addLoopAddr(NULL);
}

int AddBreakAddr(Inst *addr)
{
    if (LoopStackPtr == LoopStack) return 1;
    addLoopAddr(addr);
    *addr = NEEDS_BREAK;
    return 0;
}

int AddContinueAddr(Inst *addr)
{   
    if (LoopStackPtr == LoopStack) return 1;
    addLoopAddr(addr);
    *addr = NEEDS_CONTINUE;
    return 0;
}

static void addLoopAddr(Inst *addr)
{
    if (LoopStackPtr > &LoopStack[LOOP_STACK_SIZE-1]) {
    	fprintf(stderr, "NEdit: loop stack overflow in macro parser");
    	return;
    }
    *LoopStackPtr++ = addr;
}

void FillLoopAddrs(Inst *breakAddr, Inst *continueAddr)
{
    while (True) {
    	LoopStackPtr--;
    	if (LoopStackPtr < LoopStack) {
    	    fprintf(stderr, "NEdit: internal error (lsu) in macro parser\n");
    	    return;
    	}
    	if (*LoopStackPtr == NULL)
    	    break;
    	if (**LoopStackPtr == NEEDS_BREAK)
    	    **(Inst ***)LoopStackPtr = (Inst *)(breakAddr - *LoopStackPtr);
    	else if (**LoopStackPtr == NEEDS_CONTINUE)
    	    **(Inst ***)LoopStackPtr = (Inst *)(continueAddr - *LoopStackPtr);
    	else
    	    fprintf(stderr, "NEdit: internal error (uat) in macro parser\n");
    }
}

/*
** Execute a compiled macro, "prog", using the arguments in the array
** "args".  Returns one of MACRO_DONE, MACRO_PREEMPT, or MACRO_ERROR.
** if MACRO_DONE is returned, the macro completed, and the returned value
** (if any) can be read from "result".  If MACRO_PREEMPT is returned, the
** macro exceeded its alotted time-slice and scheduled...
*/
int ExecuteMacro(WindowInfo *window, Program *prog, int nArgs, DataValue *args,
    	DataValue *result, RestartData **continuation, char **msg)
{
    RestartData *context;
    static DataValue noValue = {NO_TAG, {0}};
    Symbol *s;
    int i;
    
    /* Create an execution context (a stack, a stack pointer, a frame pointer,
       and a program counter) which will retain the program state across
       preemption and resumption of execution */
    context = (RestartData *)XtMalloc(sizeof(RestartData));
    context->stack = (DataValue *)XtMalloc(sizeof(DataValue) * STACK_SIZE);
    *continuation = context;
    context->stackP = context->stack;
    context->pc = prog->code;
    context->runWindow = window;
    context->focusWindow = window;

    /* Push arguments and call information onto the stack */
    for (i=0; i<nArgs; i++)
    	*(context->stackP++) = args[i];