lemon.c

一个小型的嵌入式数据库

  errmsgsize = strlen(errmsg);
  /* Remove trailing '\n's from the error message. */
  while( errmsgsize>0 && errmsg[errmsgsize-1]=='\n' ){
     errmsg[--errmsgsize] = 0;
  }

  /* Print the error message */
  base = 0;
  while( errmsg[base]!=0 ){
    end = restart = findbreak(&errmsg[base],0,availablewidth);
    restart += base;
    while( errmsg[restart]==' ' ) restart++;
    fprintf(stdout,"%s%.*s\n",prefix,end,&errmsg[base]);
    base = restart;
  }
}
/**************** From the file "main.c" ************************************/
/*
** Main program file for the LEMON parser generator.
*/

/* Report an out-of-memory condition and abort.  This function
** is used mostly by the "MemoryCheck" macro in struct.h
*/
void memory_error(){
  fprintf(stderr,"Out of memory.  Aborting...\n");
  exit(1);
}

static int nDefine = 0;      /* Number of -D options on the command line */
static char **azDefine = 0;  /* Name of the -D macros */

/* This routine is called with the argument to each -D command-line option.
** Add the macro defined to the azDefine array.
*/
static void handle_D_option(char *z){
  char **paz;
  nDefine++;
  azDefine = realloc(azDefine, sizeof(azDefine[0])*nDefine);
  if( azDefine==0 ){
    fprintf(stderr,"out of memory\n");
    exit(1);
  }
  paz = &azDefine[nDefine-1];
  *paz = malloc( strlen(z)+1 );
  if( *paz==0 ){
    fprintf(stderr,"out of memory\n");
    exit(1);
  }
  strcpy(*paz, z);
  for(z=*paz; *z && *z!='='; z++){}
  *z = 0;
}


/* The main program.  Parse the command line and do it... */
int main(argc,argv)
int argc;
char **argv;
{
  static int version = 0;
  static int rpflag = 0;
  static int basisflag = 0;
  static int compress = 0;
  static int quiet = 0;
  static int statistics = 0;
  static int mhflag = 0;
  static struct s_options options[] = {
    {OPT_FLAG, "b", (char*)&basisflag, "Print only the basis in report."},
    {OPT_FLAG, "c", (char*)&compress, "Don't compress the action table."},
    {OPT_FSTR, "D", (char*)handle_D_option, "Define an %ifdef macro."},
    {OPT_FLAG, "g", (char*)&rpflag, "Print grammar without actions."},
    {OPT_FLAG, "m", (char*)&mhflag, "Output a makeheaders compatible file"},
    {OPT_FLAG, "q", (char*)&quiet, "(Quiet) Don't print the report file."},
    {OPT_FLAG, "s", (char*)&statistics,
                                   "Print parser stats to standard output."},
    {OPT_FLAG, "x", (char*)&version, "Print the version number."},
    {OPT_FLAG,0,0,0}
  };
  int i;
  struct lemon lem;

  OptInit(argv,options,stderr);
  if( version ){
     printf("Lemon version 1.0\n");
     exit(0); 
  }
  if( OptNArgs()!=1 ){
    fprintf(stderr,"Exactly one filename argument is required.\n");
    exit(1);
  }
  lem.errorcnt = 0;

  /* Initialize the machine */
  Strsafe_init();
  Symbol_init();
  State_init();
  lem.argv0 = argv[0];
  lem.filename = OptArg(0);
  lem.basisflag = basisflag;
  lem.has_fallback = 0;
  lem.nconflict = 0;
  lem.name = lem.include = lem.arg = lem.tokentype = lem.start = 0;
  lem.vartype = 0;
  lem.stacksize = 0;
  lem.error = lem.overflow = lem.failure = lem.accept = lem.tokendest =
     lem.tokenprefix = lem.outname = lem.extracode = 0;
  lem.vardest = 0;
  lem.tablesize = 0;
  Symbol_new("$");
  lem.errsym = Symbol_new("error");

  /* Parse the input file */
  Parse(&lem);
  if( lem.errorcnt ) exit(lem.errorcnt);
  if( lem.rule==0 ){
    fprintf(stderr,"Empty grammar.\n");
    exit(1);
  }

  /* Count and index the symbols of the grammar */
  lem.nsymbol = Symbol_count();
  Symbol_new("{default}");
  lem.symbols = Symbol_arrayof();
  for(i=0; i<=lem.nsymbol; i++) lem.symbols[i]->index = i;
  qsort(lem.symbols,lem.nsymbol+1,sizeof(struct symbol*),
        (int(*)())Symbolcmpp);
  for(i=0; i<=lem.nsymbol; i++) lem.symbols[i]->index = i;
  for(i=1; isupper(lem.symbols[i]->name[0]); i++);
  lem.nterminal = i;

  /* Generate a reprint of the grammar, if requested on the command line */
  if( rpflag ){
    Reprint(&lem);
  }else{
    /* Initialize the size for all follow and first sets */
    SetSize(lem.nterminal);

    /* Find the precedence for every production rule (that has one) */
    FindRulePrecedences(&lem);

    /* Compute the lambda-nonterminals and the first-sets for every
    ** nonterminal */
    FindFirstSets(&lem);

    /* Compute all LR(0) states.  Also record follow-set propagation
    ** links so that the follow-set can be computed later */
    lem.nstate = 0;
    FindStates(&lem);
    lem.sorted = State_arrayof();

    /* Tie up loose ends on the propagation links */
    FindLinks(&lem);

    /* Compute the follow set of every reducible configuration */
    FindFollowSets(&lem);

    /* Compute the action tables */
    FindActions(&lem);

    /* Compress the action tables */
    if( compress==0 ) CompressTables(&lem);

    /* Generate a report of the parser generated.  (the "y.output" file) */
    if( !quiet ) ReportOutput(&lem);

    /* Generate the source code for the parser */
    ReportTable(&lem, mhflag);

    /* Produce a header file for use by the scanner.  (This step is
    ** omitted if the "-m" option is used because makeheaders will
    ** generate the file for us.) */
    if( !mhflag ) ReportHeader(&lem);
  }
  if( statistics ){
    printf("Parser statistics: %d terminals, %d nonterminals, %d rules\n",
      lem.nterminal, lem.nsymbol - lem.nterminal, lem.nrule);
    printf("                   %d states, %d parser table entries, %d conflicts\n",
      lem.nstate, lem.tablesize, lem.nconflict);
  }
  if( lem.nconflict ){
    fprintf(stderr,"%d parsing conflicts.\n",lem.nconflict);
  }
  exit(lem.errorcnt + lem.nconflict);
  return (lem.errorcnt + lem.nconflict);
}
/******************** From the file "msort.c" *******************************/
/*
** A generic merge-sort program.
**
** USAGE:
** Let "ptr" be a pointer to some structure which is at the head of
** a null-terminated list.  Then to sort the list call:
**
**     ptr = msort(ptr,&(ptr->next),cmpfnc);
**
** In the above, "cmpfnc" is a pointer to a function which compares
** two instances of the structure and returns an integer, as in
** strcmp.  The second argument is a pointer to the pointer to the
** second element of the linked list.  This address is used to compute
** the offset to the "next" field within the structure.  The offset to
** the "next" field must be constant for all structures in the list.
**
** The function returns a new pointer which is the head of the list
** after sorting.
**
** ALGORITHM:
** Merge-sort.
*/

/*
** Return a pointer to the next structure in the linked list.
*/
#define NEXT(A) (*(char**)(((unsigned long)A)+offset))

/*
** Inputs:
**   a:       A sorted, null-terminated linked list.  (May be null).
**   b:       A sorted, null-terminated linked list.  (May be null).
**   cmp:     A pointer to the comparison function.
**   offset:  Offset in the structure to the "next" field.
**
** Return Value:
**   A pointer to the head of a sorted list containing the elements
**   of both a and b.
**
** Side effects:
**   The "next" pointers for elements in the lists a and b are
**   changed.
*/
static char *merge(a,b,cmp,offset)
char *a;
char *b;
int (*cmp)();
int offset;
{
  char *ptr, *head;

  if( a==0 ){
    head = b;
  }else if( b==0 ){
    head = a;
  }else{
    if( (*cmp)(a,b)<0 ){
      ptr = a;
      a = NEXT(a);
    }else{
      ptr = b;
      b = NEXT(b);
    }
    head = ptr;
    while( a && b ){
      if( (*cmp)(a,b)<0 ){
        NEXT(ptr) = a;
        ptr = a;
        a = NEXT(a);
      }else{
        NEXT(ptr) = b;
        ptr = b;
        b = NEXT(b);
      }
    }
    if( a ) NEXT(ptr) = a;
    else    NEXT(ptr) = b;
  }
  return head;
}

/*
** Inputs:
**   list:      Pointer to a singly-linked list of structures.
**   next:      Pointer to pointer to the second element of the list.
**   cmp:       A comparison function.
**
** Return Value:
**   A pointer to the head of a sorted list containing the elements
**   orginally in list.
**
** Side effects:
**   The "next" pointers for elements in list are changed.
*/
#define LISTSIZE 30
char *msort(list,next,cmp)
char *list;
char **next;
int (*cmp)();
{
  unsigned long offset;
  char *ep;
  char *set[LISTSIZE];
  int i;
  offset = (unsigned long)next - (unsigned long)list;
  for(i=0; i<LISTSIZE; i++) set[i] = 0;
  while( list ){
    ep = list;
    list = NEXT(list);
    NEXT(ep) = 0;
    for(i=0; i<LISTSIZE-1 && set[i]!=0; i++){
      ep = merge(ep,set[i],cmp,offset);
      set[i] = 0;
    }
    set[i] = ep;
  }
  ep = 0;
  for(i=0; i<LISTSIZE; i++) if( set[i] ) ep = merge(ep,set[i],cmp,offset);
  return ep;
}
/************************ From the file "option.c" **************************/
static char **argv;
static struct s_options *op;
static FILE *errstream;

#define ISOPT(X) ((X)[0]=='-'||(X)[0]=='+'||strchr((X),'=')!=0)

/*
** Print the command line with a carrot pointing to the k-th character
** of the n-th field.
*/
static void errline(n,k,err)
int n;
int k;
FILE *err;
{
  int spcnt, i;
  if( argv[0] ) fprintf(err,"%s",argv[0]);
  spcnt = strlen(argv[0]) + 1;
  for(i=1; i<n && argv[i]; i++){
    fprintf(err," %s",argv[i]);
    spcnt += strlen(argv[i])+1;
  }
  spcnt += k;
  for(; argv[i]; i++) fprintf(err," %s",argv[i]);
  if( spcnt<20 ){
    fprintf(err,"\n%*s^-- here\n",spcnt,"");
  }else{
    fprintf(err,"\n%*shere --^\n",spcnt-7,"");
  }
}

/*
** Return the index of the N-th non-switch argument.  Return -1
** if N is out of range.
*/
static int argindex(n)
int n;
{
  int i;
  int dashdash = 0;
  if( argv!=0 && *argv!=0 ){
    for(i=1; argv[i]; i++){
      if( dashdash || !ISOPT(argv[i]) ){
        if( n==0 ) return i;
        n--;
      }
      if( strcmp(argv[i],"--")==0 ) dashdash = 1;
    }
  }
  return -1;
}

static char emsg[] = "Command line syntax error: ";

/*
** Process a flag command line argument.
*/
static int handleflags(i,err)
int i;
FILE *err;
{
  int v;
  int errcnt = 0;
  int j;
  for(j=0; op[j].label; j++){
    if( strncmp(&argv[i][1],op[j].label,strlen(op[j].label))==0 ) break;
  }
  v = argv[i][0]=='-' ? 1 : 0;
  if( op[j].label==0 ){
    if( err ){
      fprintf(err,"%sundefined option.\n",emsg);
      errline(i,1,err);
    }
    errcnt++;
  }else if( op[j].type==OPT_FLAG ){
    *((int*)op[j].arg) = v;
  }else if( op[j].type==OPT_FFLAG ){
    (*(void(*)())(op[j].arg))(v);
  }else if( op[j].type==OPT_FSTR ){
    (*(void(*)())(op[j].arg))(&argv[i][2]);
  }else{
    if( err ){
      fprintf(err,"%smissing argument on switch.\n",emsg);
      errline(i,1,err);
    }
    errcnt++;
  }
  return errcnt;
}

/*
** Process a command line switch which has an argument.
*/
static int handleswitch(i,err)
int i;
FILE *err;
{
  int lv = 0;
  double dv = 0.0;
  char *sv = 0, *end;
  char *cp;
  int j;
  int errcnt = 0;
  cp = strchr(argv[i],'=');
  *cp = 0;
  for(j=0; op[j].label; j++){
    if( strcmp(argv[i],op[j].label)==0 ) break;
  }
  *cp = '=';
  if( op[j].label==0 ){
    if( err ){
      fprintf(err,"%sundefined option.\n",emsg);
      errline(i,0,err);
    }
    errcnt++;
  }else{
    cp++;
    switch( op[j].type ){
      case OPT_FLAG:
      case OPT_FFLAG: