/examples/kegogi/lemon.c

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/*
** This file contains all sources (including headers) to the LEMON
** LALR(1) parser generator.  The sources have been combined into a
** single file to make it easy to include LEMON in the source tree
** and Makefile of another program.
**
** The author of this program disclaims copyright.
*/
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#include <assert.h>

#ifndef __WIN32__
#   if defined(_WIN32) || defined(WIN32)
#	define __WIN32__
#   endif
#endif

#ifdef __WIN32__
extern int access();
#else
#include <unistd.h>
#endif

/* #define PRIVATE static */
#define PRIVATE

#ifdef TEST
#define MAXRHS 5       /* Set low to exercise exception code */
#else
#define MAXRHS 1000
#endif

static char *msort(char*,char**,int(*)(const char*,const char*));

/*
** Compilers are getting increasingly pedantic about type conversions
** as C evolves ever closer to Ada....  To work around the latest problems
** we have to define the following variant of strlen().
*/
#define lemonStrlen(X)   ((int)strlen(X))

static struct action *Action_new(void);
static struct action *Action_sort(struct action *);

/********** From the file "build.h" ************************************/
void FindRulePrecedences();
void FindFirstSets();
void FindStates();
void FindLinks();
void FindFollowSets();
void FindActions();

/********* From the file "configlist.h" *********************************/
void Configlist_init(/* void */);
struct config *Configlist_add(/* struct rule *, int */);
struct config *Configlist_addbasis(/* struct rule *, int */);
void Configlist_closure(/* void */);
void Configlist_sort(/* void */);
void Configlist_sortbasis(/* void */);
struct config *Configlist_return(/* void */);
struct config *Configlist_basis(/* void */);
void Configlist_eat(/* struct config * */);
void Configlist_reset(/* void */);

/********* From the file "error.h" ***************************************/
void ErrorMsg(const char *, int,const char *, ...);

/****** From the file "option.h" ******************************************/
struct s_options {
  enum { OPT_FLAG=1,  OPT_INT,  OPT_DBL,  OPT_STR,
         OPT_FFLAG, OPT_FINT, OPT_FDBL, OPT_FSTR} type;
  char *label;
  char *arg;
  char *message;
};
int    OptInit(/* char**,struct s_options*,FILE* */);
int    OptNArgs(/* void */);
char  *OptArg(/* int */);
void   OptErr(/* int */);
void   OptPrint(/* void */);

/******** From the file "parse.h" *****************************************/
void Parse(/* struct lemon *lemp */);

/********* From the file "plink.h" ***************************************/
struct plink *Plink_new(/* void */);
void Plink_add(/* struct plink **, struct config * */);
void Plink_copy(/* struct plink **, struct plink * */);
void Plink_delete(/* struct plink * */);

/********** From the file "report.h" *************************************/
void Reprint(/* struct lemon * */);
void ReportOutput(/* struct lemon * */);
void ReportTable(/* struct lemon * */);
void ReportHeader(/* struct lemon * */);
void CompressTables(/* struct lemon * */);
void ResortStates(/* struct lemon * */);

/********** From the file "set.h" ****************************************/
void  SetSize(/* int N */);             /* All sets will be of size N */
char *SetNew(/* void */);               /* A new set for element 0..N */
void  SetFree(/* char* */);             /* Deallocate a set */

int SetAdd(/* char*,int */);            /* Add element to a set */
int SetUnion(/* char *A,char *B */);    /* A <- A U B, thru element N */

#define SetFind(X,Y) (X[Y])       /* True if Y is in set X */

/********** From the file "struct.h" *************************************/
/*
** Principal data structures for the LEMON parser generator.
*/

typedef enum {LEMON_FALSE=0, LEMON_TRUE} Boolean;

/* Symbols (terminals and nonterminals) of the grammar are stored
** in the following: */
struct symbol {
  char *name;              /* Name of the symbol */
  int index;               /* Index number for this symbol */
  enum {
    TERMINAL,
    NONTERMINAL,
    MULTITERMINAL
  } type;                  /* Symbols are all either TERMINALS or NTs */
  struct rule *rule;       /* Linked list of rules of this (if an NT) */
  struct symbol *fallback; /* fallback token in case this token doesn't parse */
  int prec;                /* Precedence if defined (-1 otherwise) */
  enum e_assoc {
    LEFT,
    RIGHT,
    NONE,
    UNK
  } assoc;                 /* Associativity if precedence is defined */
  char *firstset;          /* First-set for all rules of this symbol */
  Boolean lambda;          /* True if NT and can generate an empty string */
  int useCnt;              /* Number of times used */
  char *destructor;        /* Code which executes whenever this symbol is
                           ** popped from the stack during error processing */
  int destLineno;          /* Line number for start of destructor */
  char *datatype;          /* The data type of information held by this
                           ** object. Only used if type==NONTERMINAL */
  int dtnum;               /* The data type number.  In the parser, the value
                           ** stack is a union.  The .yy%d element of this
                           ** union is the correct data type for this object */
  /* The following fields are used by MULTITERMINALs only */
  int nsubsym;             /* Number of constituent symbols in the MULTI */
  struct symbol **subsym;  /* Array of constituent symbols */
};

/* Each production rule in the grammar is stored in the following
** structure.  */
struct rule {
  struct symbol *lhs;      /* Left-hand side of the rule */
  char *lhsalias;          /* Alias for the LHS (NULL if none) */
  int lhsStart;            /* True if left-hand side is the start symbol */
  int ruleline;            /* Line number for the rule */
  int nrhs;                /* Number of RHS symbols */
  struct symbol **rhs;     /* The RHS symbols */
  char **rhsalias;         /* An alias for each RHS symbol (NULL if none) */
  int line;                /* Line number at which code begins */
  char *code;              /* The code executed when this rule is reduced */
  struct symbol *precsym;  /* Precedence symbol for this rule */
  int index;               /* An index number for this rule */
  Boolean canReduce;       /* True if this rule is ever reduced */
  struct rule *nextlhs;    /* Next rule with the same LHS */
  struct rule *next;       /* Next rule in the global list */
};

/* A configuration is a production rule of the grammar together with
** a mark (dot) showing how much of that rule has been processed so far.
** Configurations also contain a follow-set which is a list of terminal
** symbols which are allowed to immediately follow the end of the rule.
** Every configuration is recorded as an instance of the following: */
struct config {
  struct rule *rp;         /* The rule upon which the configuration is based */
  int dot;                 /* The parse point */
  char *fws;               /* Follow-set for this configuration only */
  struct plink *fplp;      /* Follow-set forward propagation links */
  struct plink *bplp;      /* Follow-set backwards propagation links */
  struct state *stp;       /* Pointer to state which contains this */
  enum {
    COMPLETE,              /* The status is used during followset and */
    INCOMPLETE             /*    shift computations */
  } status;
  struct config *next;     /* Next configuration in the state */
  struct config *bp;       /* The next basis configuration */
};

/* Every shift or reduce operation is stored as one of the following */
struct action {
  struct symbol *sp;       /* The look-ahead symbol */
  enum e_action {
    SHIFT,
    ACCEPT,
    REDUCE,
    ERROR,
    SSCONFLICT,              /* A shift/shift conflict */
    SRCONFLICT,              /* Was a reduce, but part of a conflict */
    RRCONFLICT,              /* Was a reduce, but part of a conflict */
    SH_RESOLVED,             /* Was a shift.  Precedence resolved conflict */
    RD_RESOLVED,             /* Was reduce.  Precedence resolved conflict */
    NOT_USED                 /* Deleted by compression */
  } type;
  union {
    struct state *stp;     /* The new state, if a shift */
    struct rule *rp;       /* The rule, if a reduce */
  } x;
  struct action *next;     /* Next action for this state */
  struct action *collide;  /* Next action with the same hash */
};

/* Each state of the generated parser's finite state machine
** is encoded as an instance of the following structure. */
struct state {
  struct config *bp;       /* The basis configurations for this state */
  struct config *cfp;      /* All configurations in this set */
  int statenum;            /* Sequential number for this state */
  struct action *ap;       /* Array of actions for this state */
  int nTknAct, nNtAct;     /* Number of actions on terminals and nonterminals */
  int iTknOfst, iNtOfst;   /* yy_action[] offset for terminals and nonterms */
  int iDflt;               /* Default action */
};
#define NO_OFFSET (-2147483647)

/* A followset propagation link indicates that the contents of one
** configuration followset should be propagated to another whenever
** the first changes. */
struct plink {
  struct config *cfp;      /* The configuration to which linked */
  struct plink *next;      /* The next propagate link */
};

/* The state vector for the entire parser generator is recorded as
** follows.  (LEMON uses no global variables and makes little use of
** static variables.  Fields in the following structure can be thought
** of as begin global variables in the program.) */
struct lemon {
  struct state **sorted;   /* Table of states sorted by state number */
  struct rule *rule;       /* List of all rules */
  int nstate;              /* Number of states */
  int nrule;               /* Number of rules */
  int nsymbol;             /* Number of terminal and nonterminal symbols */
  int nterminal;           /* Number of terminal symbols */
  struct symbol **symbols; /* Sorted array of pointers to symbols */
  int errorcnt;            /* Number of errors */
  struct symbol *errsym;   /* The error symbol */
  struct symbol *wildcard; /* Token that matches anything */
  char *name;              /* Name of the generated parser */
  char *arg;               /* Declaration of the 3th argument to parser */
  char *tokentype;         /* Type of terminal symbols in the parser stack */
  char *vartype;           /* The default type of non-terminal symbols */
  char *start;             /* Name of the start symbol for the grammar */
  char *stacksize;         /* Size of the parser stack */
  char *include;           /* Code to put at the start of the C file */
  char *error;             /* Code to execute when an error is seen */
  char *overflow;          /* Code to execute on a stack overflow */
  char *failure;           /* Code to execute on parser failure */
  char *accept;            /* Code to execute when the parser excepts */
  char *extracode;         /* Code appended to the generated file */
  char *tokendest;         /* Code to execute to destroy token data */
  char *vardest;           /* Code for the default non-terminal destructor */
  char *filename;          /* Name of the input file */
  char *outname;           /* Name of the current output file */
  char *tokenprefix;       /* A prefix added to token names in the .h file */
  int nconflict;           /* Number of parsing conflicts */
  int tablesize;           /* Size of the parse tables */
  int basisflag;           /* Print only basis configurations */
  int has_fallback;        /* True if any %fallback is seen in the grammar */
  int nolinenosflag;       /* True if #line statements should not be printed */
  char *argv0;             /* Name of the program */
};

#define MemoryCheck(X) if((X)==0){ \
  extern void memory_error(); \
  memory_error(); \
}

/**************** From the file "table.h" *********************************/
/*
** All code in this file has been automatically generated
** from a specification in the file
**              "table.q"
** by the associative array code building program "aagen".
** Do not edit this file!  Instead, edit the specification
** file, then rerun aagen.
*/
/*
** Code for processing tables in the LEMON parser generator.
*/

/* Routines for handling a strings */

char *Strsafe();

void Strsafe_init(/* void */);
int Strsafe_insert(/* char * */);
char *Strsafe_find(/* char * */);

/* Routines for handling symbols of the grammar */

struct symbol *Symbol_new();
int Symbolcmpp(/* struct symbol **, struct symbol ** */);
void Symbol_init(/* void */);
int Symbol_insert(/* struct symbol *, char * */);
struct symbol *Symbol_find(/* char * */);
struct symbol *Symbol_Nth(/* int */);
int Symbol_count(/*  */);
struct symbol **Symbol_arrayof(/*  */);

/* Routines to manage the state table */

int Configcmp(/* struct config *, struct config * */);
struct state *State_new();
void State_init(/* void */);
int State_insert(/* struct state *, struct config * */);
struct state *State_find(/* struct config * */);
struct state **State_arrayof(/*  */);

/* Routines used for efficiency in Configlist_add */

void Configtable_init(/* void */);
int Configtable_insert(/* struct config * */);
struct config *Configtable_find(/* struct config * */);
void Configtable_clear(/* int(*)(struct config *) */);
/****************** From the file "action.c" *******************************/
/*
** Routines processing parser actions in the LEMON parser generator.
*/

/* Allocate a new parser action */
static struct action *Action_new(void){
  static struct action *freelist = 0;
  struct action *new;

  if( freelist==0 ){
    int i;
    int amt = 100;
    freelist = (struct action *)calloc(amt, sizeof(struct action));
    if( freelist==0 ){
      fprintf(stderr,"Unable to allocate memory for a new parser action.");
      exit(1);
    }
    for(i=0; i<amt-1; i++) freelist[i].next = &freelist[i+1];
    freelist[amt-1].next = 0;
  }
  new = freelist;
  freelist = freelist->next;
  return new;
}

/* Compare two actions for sorting purposes.  Return negative, zero, or
** positive if the first action is less than, equal to, or greater than
** the first
*/
static int actioncmp(
  struct action *ap1,
  struct action *ap2
){
  int rc;
  rc = ap1->sp->index - ap2->sp->index;
  if( rc==0 ){
    rc = (int)ap1->type - (int)ap2->type;
  }
  if( rc==0 && ap1->type==REDUCE ){
    rc = ap1->x.rp->index - ap2->x.rp->index;
  }
  return rc;
}

/* Sort parser actions */
static struct action *Action_sort(
  struct action *ap
){
  ap = (struct action *)msort((char *)ap,(char **)&ap->next,
                              (int(*)(const char*,const char*))actioncmp);
  return ap;
}

void Action_add(app,type,sp,arg)
struct action **app;
enum e_action type;
struct symbol *sp;
char *arg;
{
  struct action *new;
  new = Action_new();
  new->next = *app;
  *app = new;
  new->type = type;
  new->sp = sp;
  if( type==SHIFT ){
    new->x.stp = (struct state *)arg;
  }else{
    new->x.rp = (struct rule *)arg;
  }
}
/********************** New code to implement the "acttab" module ***********/
/*
** This module implements routines use to construct the yy_action[] table.
*/

/*
** The state of the yy_action table under construction is an instance of
** the following structure
*/
typedef struct acttab acttab;
struct acttab {
  int nAction;                 /* Number of used slots in aAction[] */
  int nActionAlloc;            /* Slots allocated for aAction[] */
  struct {
    int lookahead;             /* Value of the lookahead token */
    int action;                /* Action to take on the given lookahead */
  } *aAction,                  /* The yy_action[] table under construction */
    *aLookahead;               /* A single new transaction set */
  int mnLookahead;             /* Minimum aLookahead[].lookahead */
  int mnAction;                /* Action associated with mnLookahead */
  int mxLookahead;             /* Maximum aLookahead[].lookahead */
  int nLookahead;              /* Used slots in aLookahead[] */
  int nLookaheadAlloc;         /* Slots allocated in aLookahead[] */
};

/* Return the number of entries in the yy_action table */
#define acttab_size(X) ((X)->nAction)

/* The value for the N-th entry in yy_action */
#define acttab_yyaction(X,N)  ((X)->aAction[N].action)

/* The value for the N-th entry in yy_lookahead */
#define acttab_yylookahead(X,N)  ((X)->aAction[N].lookahead)

/* Free all memory associated with the given acttab */
void acttab_free(acttab *p){
  free( p->aAction );
  free( p->aLookahead );
  free( p );
}

/* Allocate a new acttab structure */
acttab *acttab_alloc(void){
  acttab *p = calloc( 1, sizeof(*p) );
  if( p==0 ){
    fprintf(stderr,"Unable to allocate memory for a new acttab.");
    exit(1);
  }
  memset(p, 0, sizeof(*p));
  return p;
}

/* Add a new action to the current transaction set
*/
void acttab_action(acttab *p, int lookahead, int action){
  if( p->nLookahead>=p->nLookaheadAlloc ){
    p->nLookaheadAlloc += 25;
    p->aLookahead = realloc( p->aLookahead,
                             sizeof(p->aLookahead[0])*p->nLookaheadAlloc );
    if( p->aLookahead==0 ){
      fprintf(stderr,"malloc failed\n");
      exit(1);
    }
  }
  if( p->nLookahead==0 ){
    p->mxLookahead = lookahead;
    p->mnLookahead = lookahead;
    p->mnAction = action;
  }else{
    if( p->mxLookahead<lookahead ) p->mxLookahead = lookahead;
    if( p->mnLookahead>lookahead ){
      p->mnLookahead = lookahead;
      p->mnAction = action;
    }
  }
  p->aLookahead[p->nLookahead].lookahead = lookahead;
  p->aLookahead[p->nLookahead].action = action;
  p->nLookahead++;
}

/*
** Add the transaction set built up with prior calls to acttab_action()
** into the current action table.  Then reset the transaction set back
** to an empty set in preparation for a new round of acttab_action() calls.
**
** Return the offset into the action table of the new transaction.
*/
int acttab_insert(acttab *p){
  int i, j, k, n;
  assert( p->nLookahead>0 );

  /* Make sure we have enough space to hold the expanded action table
  ** in the worst case.  The worst case occurs if the transaction set
  ** must be appended to the current action table
  */
  n = p->mxLookahead + 1;
  if( p->nAction + n >= p->nActionAlloc ){
    int oldAlloc = p->nActionAlloc;
    p->nActionAlloc = p->nAction + n + p->nActionAlloc + 20;
    p->aAction = realloc( p->aAction,
                          sizeof(p->aAction[0])*p->nActionAlloc);
    if( p->aAction==0 ){
      fprintf(stderr,"malloc failed\n");
      exit(1);
    }
    for(i=oldAlloc; i<p->nActionAlloc; i++){
      p->aAction[i].lookahead = -1;
      p->aAction[i].action = -1;
    }
  }

  /* Scan the existing action table looking for an offset where we can
  ** insert the current transaction set.  Fall out of the loop when that
  ** offset is found.  In the worst case, we fall out of the loop when
  ** i reaches p->nAction, which means we append the new transaction set.
  **
  ** i is the index in p->aAction[] where p->mnLookahead is inserted.
  */
  for(i=0; i<p->nAction+p->mnLookahead; i++){
    if( p->aAction[i].lookahead<0 ){
      for(j=0; j<p->nLookahead; j++){
        k = p->aLookahead[j].lookahead - p->mnLookahead + i;
        if( k<0 ) break;
        if( p->aAction[k].lookahead>=0 ) break;
      }
      if( j<p->nLookahead ) continue;
      for(j=0; j<p->nAction; j++){
        if( p->aAction[j].lookahead==j+p->mnLookahead-i ) break;
      }
      if( j==p->nAction ){
        break;  /* Fits in empty slots */
      }
    }else if( p->aAction[i].lookahead==p->mnLookahead ){
      if( p->aAction[i].action!=p->mnAction ) continue;
      for(j=0; j<p->nLookahead; j++){
        k = p->aLookahead[j].lookahead - p->mnLookahead + i;
        if( k<0 || k>=p->nAction ) break;
        if( p->aLookahead[j].lookahead!=p->aAction[k].lookahead ) break;
        if( p->aLookahead[j].action!=p->aAction[k].action ) break;
      }
      if( j<p->nLookahead ) continue;
      n = 0;
      for(j=0; j<p->nAction; j++){
        if( p->aAction[j].lookahead<0 ) continue;
        if( p->aAction[j].lookahead==j+p->mnLookahead-i ) n++;
      }
      if( n==p->nLookahead ){
        break;  /* Same as a prior transaction set */
      }
    }
  }
  /* Insert transaction set at index i. */
  for(j=0; j<p->nLookahead; j++){
    k = p->aLookahead[j].lookahead - p->mnLookahead + i;
    p->aAction[k] = p->aLookahead[j];
    if( k>=p->nAction ) p->nAction = k+1;
  }
  p->nLookahead = 0;

  /* Return the offset that is added to the lookahead in order to get the
  ** index into yy_action of the action */
  return i - p->mnLookahead;
}

/********************** From the file "build.c" *****************************/
/*
** Routines to construction the finite state machine for the LEMON
** parser generator.
*/

/* Find a precedence symbol of every rule in the grammar.
** 
** Those rules which have a precedence symbol coded in the input
** grammar using the "[symbol]" construct will already have the
** rp->precsym field filled.  Other rules take as their precedence
** symbol the first RHS symbol with a defined precedence.  If there
** are not RHS symbols with a defined precedence, the precedence
** symbol field is left blank.
*/
void FindRulePrecedences(xp)
struct lemon *xp;
{
  struct rule *rp;
  for(rp=xp->rule; rp; rp=rp->next){
    if( rp->precsym==0 ){
      int i, j;
      for(i=0; i<rp->nrhs && rp->precsym==0; i++){
        struct symbol *sp = rp->rhs[i];
        if( sp->type==MULTITERMINAL ){
          for(j=0; j<sp->nsubsym; j++){
            if( sp->subsym[j]->prec>=0 ){
              rp->precsym = sp->subsym[j];
              break;
            }
          }
        }else if( sp->prec>=0 ){
          rp->precsym = rp->rhs[i];
	}
      }
    }
  }
  return;
}

/* Find all nonterminals which will generate the empty string.
** Then go back and compute the first sets of every nonterminal.
** The first set is the set of all terminal symbols which can begin
** a string generated by that nonterminal.
*/
void FindFirstSets(lemp)
struct lemon *lemp;
{
  int i, j;
  struct rule *rp;
  int progress;

  for(i=0; i<lemp->nsymbol; i++){
    lemp->symbols[i]->lambda = LEMON_FALSE;
  }
  for(i=lemp->nterminal; i<lemp->nsymbol; i++){
    lemp->symbols[i]->firstset = SetNew();
  }

  /* First compute all lambdas */
  do{
    progress = 0;
    for(rp=lemp->rule; rp; rp=rp->next){
      if( rp->lhs->lambda ) continue;
      for(i=0; i<rp->nrhs; i++){
         struct symbol *sp = rp->rhs[i];
         if( sp->type!=TERMINAL || sp->lambda==LEMON_FALSE ) break;
      }
      if( i==rp->nrhs ){
        rp->lhs->lambda = LEMON_TRUE;
        progress = 1;
      }
    }
  }while( progress );

  /* Now compute all first sets */
  do{
    struct symbol *s1, *s2;
    progress = 0;
    for(rp=lemp->rule; rp; rp=rp->next){
      s1 = rp->lhs;
      for(i=0; i<rp->nrhs; i++){
        s2 = rp->rhs[i];
        if( s2->type==TERMINAL ){
          progress += SetAdd(s1->firstset,s2->index);
          break;
        }else if( s2->type==MULTITERMINAL ){
          for(j=0; j<s2->nsubsym; j++){
            progress += SetAdd(s1->firstset,s2->subsym[j]->index);
          }
          break;
	}else if( s1==s2 ){
          if( s1->lambda==LEMON_FALSE ) break;
	}else{
          progress += SetUnion(s1->firstset,s2->firstset);
          if( s2->lambda==LEMON_FALSE ) break;
	}
      }
    }
  }while( progress );
  return;
}

/* Compute all LR(0) states for the grammar.  Links
** are added to between some states so that the LR(1) follow sets
** can be computed later.
*/
PRIVATE struct state *getstate(/* struct lemon * */);  /* forward reference */
void FindStates(lemp)
struct lemon *lemp;
{
  struct symbol *sp;
  struct rule *rp;

  Configlist_init();

  /* Find the start symbol */
  if( lemp->start ){
    sp = Symbol_find(lemp->start);
    if( sp==0 ){
      ErrorMsg(lemp->filename,0,
"The specified start symbol \"%s\" is not \
in a nonterminal of the grammar.  \"%s\" will be used as the start \
symbol instead.",lemp->start,lemp->rule->lhs->name);
      lemp->errorcnt++;
      sp = lemp->rule->lhs;
    }
  }else{
    sp = lemp->rule->lhs;
  }

  /* Make sure the start symbol doesn't occur on the right-hand side of
  ** any rule.  Report an error if it does.  (YACC would generate a new
  ** start symbol in this case.) */
  for(rp=lemp->rule; rp; rp=rp->next){
    int i;
    for(i=0; i<rp->nrhs; i++){
      if( rp->rhs[i]==sp ){   /* FIX ME:  Deal with multiterminals */
        ErrorMsg(lemp->filename,0,
"The start symbol \"%s\" occurs on the \
right-hand side of a rule. This will result in a parser which \
does not work properly.",sp->name);
        lemp->errorcnt++;
      }
    }
  }

  /* The basis configuration set for the first state
  ** is all rules which have the start symbol as their
  ** left-hand side */
  for(rp=sp->rule; rp; rp=rp->nextlhs){
    struct config *newcfp;
    rp->lhsStart = 1;
    newcfp = Configlist_addbasis(rp,0);
    SetAdd(newcfp->fws,0);
  }

  /* Compute the first state.  All other states will be
  ** computed automatically during the computation of the first one.
  ** The returned pointer to the first state is not used. */
  (void)getstate(lemp);
  return;
}

/* Return a pointer to a state which is described by the configuration
** list which has been built from calls to Configlist_add.
*/
PRIVATE void buildshifts(/* struct lemon *, struct state * */); /* Forwd ref */
PRIVATE struct state *getstate(lemp)
struct lemon *lemp;
{
  struct config *cfp, *bp;
  struct state *stp;

  /* Extract the sorted basis of the new state.  The basis was constructed
  ** by prior calls to "Configlist_addbasis()". */
  Configlist_sortbasis();
  bp = Configlist_basis();

  /* Get a state with the same basis */
  stp = State_find(bp);
  if( stp ){
    /* A state with the same basis already exists!  Copy all the follow-set
    ** propagation links from the state under construction into the
    ** preexisting state, then return a pointer to the preexisting state */
    struct config *x, *y;
    for(x=bp, y=stp->bp; x && y; x=x->bp, y=y->bp){
      Plink_copy(&y->bplp,x->bplp);
      Plink_delete(x->fplp);
      x->fplp = x->bplp = 0;
    }
    cfp = Configlist_return();
    Configlist_eat(cfp);
  }else{
    /* This really is a new state.  Construct all the details */
    Configlist_closure(lemp);    /* Compute the configuration closure */
    Configlist_sort();           /* Sort the configuration closure */
    cfp = Configlist_return();   /* Get a pointer to the config list */
    stp = State_new();           /* A new state structure */
    MemoryCheck(stp);
    stp->bp = bp;                /* Remember the configuration basis */
    stp->cfp = cfp;              /* Remember the configuration closure */
    stp->statenum = lemp->nstate++; /* Every state gets a sequence number */
    stp->ap = 0;                 /* No actions, yet. */
    State_insert(stp,stp->bp);   /* Add to the state table */
    buildshifts(lemp,stp);       /* Recursively compute successor states */
  }
  return stp;
}

/*
** Return true if two symbols are the same.
*/
int same_symbol(a,b)
struct symbol *a;
struct symbol *b;
{
  int i;
  if( a==b ) return 1;
  if( a->type!=MULTITERMINAL ) return 0;
  if( b->type!=MULTITERMINAL ) return 0;
  if( a->nsubsym!=b->nsubsym ) return 0;
  for(i=0; i<a->nsubsym; i++){
    if( a->subsym[i]!=b->subsym[i] ) return 0;
  }
  return 1;
}

/* Construct all successor states to the given state.  A "successor"
** state is any state which can be reached by a shift action.
*/
PRIVATE void buildshifts(lemp,stp)
struct lemon *lemp;
struct state *stp;     /* The state from which successors are computed */
{
  struct config *cfp;  /* For looping thru the config closure of "stp" */
  struct config *bcfp; /* For the inner loop on config closure of "stp" */
  struct config *new;  /* */
  struct symbol *sp;   /* Symbol following the dot in configuration "cfp" */
  struct symbol *bsp;  /* Symbol following the dot in configuration "bcfp" */
  struct state *newstp; /* A pointer to a successor state */

  /* Each configuration becomes complete after it contibutes to a successor
  ** state.  Initially, all configurations are incomplete */
  for(cfp=stp->cfp; cfp; cfp=cfp->next) cfp->status = INCOMPLETE;

  /* Loop through all configurations of the state "stp" */
  for(cfp=stp->cfp; cfp; cfp=cfp->next){
    if( cfp->status==COMPLETE ) continue;    /* Already used by inner loop */
    if( cfp->dot>=cfp->rp->nrhs ) continue;  /* Can't shift this config */
    Configlist_reset();                      /* Reset the new config set */
    sp = cfp->rp->rhs[cfp->dot];             /* Symbol after the dot */

    /* For every configuration in the state "stp" which has the symbol "sp"
    ** following its dot, add the same configuration to the basis set under
    ** construction but with the dot shifted one symbol to the right. */
    for(bcfp=cfp; bcfp; bcfp=bcfp->next){
      if( bcfp->status==COMPLETE ) continue;    /* Already used */
      if( bcfp->dot>=bcfp->rp->nrhs ) continue; /* Can't shift this one */
      bsp = bcfp->rp->rhs[bcfp->dot];           /* Get symbol after dot */
      if( !same_symbol(bsp,sp) ) continue;      /* Must be same as for "cfp" */
      bcfp->status = COMPLETE;                  /* Mark this config as used */
      new = Configlist_addbasis(bcfp->rp,bcfp->dot+1);
      Plink_add(&new->bplp,bcfp);
    }

    /* Get a pointer to the state described by the basis configuration set
    ** constructed in the preceding loop */
    newstp = getstate(lemp);

    /* The state "newstp" is reached from the state "stp" by a shift action
    ** on the symbol "sp" */
    if( sp->type==MULTITERMINAL ){
      int i;
      for(i=0; i<sp->nsubsym; i++){
        Action_add(&stp->ap,SHIFT,sp->subsym[i],(char*)newstp);
      }
    }else{
      Action_add(&stp->ap,SHIFT,sp,(char *)newstp);
    }
  }
}

/*
** Construct the propagation links
*/
void FindLinks(lemp)
struct lemon *lemp;
{
  int i;
  struct config *cfp, *other;
  struct state *stp;
  struct plink *plp;

  /* Housekeeping detail:
  ** Add to every propagate link a pointer back to the state to
  ** which the link is attached. */
  for(i=0; i<lemp->nstate; i++){
    stp = lemp->sorted[i];
    for(cfp=stp->cfp; cfp; cfp=cfp->next){
      cfp->stp = stp;
    }
  }

  /* Convert all backlinks into forward links.  Only the forward
  ** links are used in the follow-set computation. */
  for(i=0; i<lemp->nstate; i++){
    stp = lemp->sorted[i];
    for(cfp=stp->cfp; cfp; cfp=cfp->next){
      for(plp=cfp->bplp; plp; plp=plp->next){
        other = plp->cfp;
        Plink_add(&other->fplp,cfp);
      }
    }
  }
}

/* Compute all followsets.
**
** A followset is the set of all symbols which can come immediately
** after a configuration.
*/
void FindFollowSets(lemp)
struct lemon *lemp;
{
  int i;
  struct config *cfp;
  struct plink *plp;
  int progress;
  int change;

  for(i=0; i<lemp->nstate; i++){
    for(cfp=lemp->sorted[i]->cfp; cfp; cfp=cfp->next){
      cfp->status = INCOMPLETE;
    }
  }
  
  do{
    progress = 0;
    for(i=0; i<lemp->nstate; i++){
      for(cfp=lemp->sorted[i]->cfp; cfp; cfp=cfp->next){
        if( cfp->status==COMPLETE ) continue;
        for(plp=cfp->fplp; plp; plp=plp->next){
          change = SetUnion(plp->cfp->fws,cfp->fws);
          if( change ){
            plp->cfp->status = INCOMPLETE;
            progress = 1;
	  }
	}
        cfp->status = COMPLETE;
      }
    }
  }while( progress );
}

static int resolve_conflict();

/* Compute the reduce actions, and resolve conflicts.
*/
void FindActions(lemp)
struct lemon *lemp;
{
  int i,j;
  struct config *cfp;
  struct state *stp;
  struct symbol *sp;
  struct rule *rp;

  /* Add all of the reduce actions 
  ** A reduce action is added for each element of the followset of
  ** a configuration which has its dot at the extreme right.
  */
  for(i=0; i<lemp->nstate; i++){   /* Loop over all states */
    stp = lemp->sorted[i];
    for(cfp=stp->cfp; cfp; cfp=cfp->next){  /* Loop over all configurations */
      if( cfp->rp->nrhs==cfp->dot ){        /* Is dot at extreme right? */
        for(j=0; j<lemp->nterminal; j++){
          if( SetFind(cfp->fws,j) ){
            /* Add a reduce action to the state "stp" which will reduce by the
            ** rule "cfp->rp" if the lookahead symbol is "lemp->symbols[j]" */
            Action_add(&stp->ap,REDUCE,lemp->symbols[j],(char *)cfp->rp);
          }
	}
      }
    }
  }

  /* Add the accepting token */
  if( lemp->start ){
    sp = Symbol_find(lemp->start);
    if( sp==0 ) sp = lemp->rule->lhs;
  }else{
    sp = lemp->rule->lhs;
  }
  /* Add to the first state (which is always the starting state of the
  ** finite state machine) an action to ACCEPT if the lookahead is the
  ** start nonterminal.  */
  Action_add(&lemp->sorted[0]->ap,ACCEPT,sp,0);

  /* Resolve conflicts */
  for(i=0; i<lemp->nstate; i++){
    struct action *ap, *nap;
    struct state *stp;
    stp = lemp->sorted[i];
    /* assert( stp->ap ); */
    stp->ap = Action_sort(stp->ap);
    for(ap=stp->ap; ap && ap->next; ap=ap->next){
      for(nap=ap->next; nap && nap->sp==ap->sp; nap=nap->next){
         /* The two actions "ap" and "nap" have the same lookahead.
         ** Figure out which one should be used */
         lemp->nconflict += resolve_conflict(ap,nap,lemp->errsym);
      }
    }
  }

  /* Report an error for each rule that can never be reduced. */
  for(rp=lemp->rule; rp; rp=rp->next) rp->canReduce = LEMON_FALSE;
  for(i=0; i<lemp->nstate; i++){
    struct action *ap;
    for(ap=lemp->sorted[i]->ap; ap; ap=ap->next){
      if( ap->type==REDUCE ) ap->x.rp->canReduce = LEMON_TRUE;
    }
  }
  for(rp=lemp->rule; rp; rp=rp->next){
    if( rp->canReduce ) continue;
    ErrorMsg(lemp->filename,rp->ruleline,"This rule can not be reduced.\n");
    lemp->errorcnt++;
  }
}

/* Resolve a conflict between the two given actions.  If the
** conflict can't be resolved, return non-zero.
**
** NO LONGER TRUE:
**   To resolve a conflict, first look to see if either action
**   is on an error rule.  In that case, take the action which
**   is not associated with the error rule.  If neither or both
**   actions are associated with an error rule, then try to
**   use precedence to resolve the conflict.
**
** If either action is a SHIFT, then it must be apx.  This
** function won't work if apx->type==REDUCE and apy->type==SHIFT.
*/
static int resolve_conflict(apx,apy,errsym)
struct action *apx;
struct action *apy;
struct symbol *errsym;   /* The error symbol (if defined.  NULL otherwise) */
{
  struct symbol *spx, *spy;
  int errcnt = 0;
  assert( apx->sp==apy->sp );  /* Otherwise there would be no conflict */
  if( apx->type==SHIFT && apy->type==SHIFT ){
    apy->type = SSCONFLICT;
    errcnt++;
  }
  if( apx->type==SHIFT && apy->type==REDUCE ){
    spx = apx->sp;
    spy = apy->x.rp->precsym;
    if( spy==0 || spx->prec<0 || spy->prec<0 ){
      /* Not enough precedence information. */
      apy->type = SRCONFLICT;
      errcnt++;
    }else if( spx->prec>spy->prec ){    /* Lower precedence wins */
      apy->type = RD_RESOLVED;
    }else if( spx->prec<spy->prec ){
      apx->type = SH_RESOLVED;
    }else if( spx->prec==spy->prec && spx->assoc==RIGHT ){ /* Use operator */
      apy->type = RD_RESOLVED;                             /* associativity */
    }else if( spx->prec==spy->prec && spx->assoc==LEFT ){  /* to break tie */
      apx->type = SH_RESOLVED;
    }else{
      assert( spx->prec==spy->prec && spx->assoc==NONE );
      apy->type = SRCONFLICT;
      errcnt++;
    }
  }else if( apx->type==REDUCE && apy->type==REDUCE ){
    spx = apx->x.rp->precsym;
    spy = apy->x.rp->precsym;
    if( spx==0 || spy==0 || spx->prec<0 ||
    spy->prec<0 || spx->prec==spy->prec ){
      apy->type = RRCONFLICT;
      errcnt++;
    }else if( spx->prec>spy->prec ){
      apy->type = RD_RESOLVED;
    }else if( spx->prec<spy->prec ){
      apx->type = RD_RESOLVED;
    }
  }else{
    assert( 
      apx->type==SH_RESOLVED ||
      apx->type==RD_RESOLVED ||
      apx->type==SSCONFLICT ||
      apx->type==SRCONFLICT ||
      apx->type==RRCONFLICT ||
      apy->type==SH_RESOLVED ||
      apy->type==RD_RESOLVED ||
      apy->type==SSCONFLICT ||
      apy->type==SRCONFLICT ||
      apy->type==RRCONFLICT
    );
    /* The REDUCE/SHIFT case cannot happen because SHIFTs come before
    ** REDUCEs on the list.  If we reach this point it must be because
    ** the parser conflict had already been resolved. */
  }
  return errcnt;
}
/********************* From the file "configlist.c" *************************/
/*
** Routines to processing a configuration list and building a state
** in the LEMON parser generator.
*/

static struct config *freelist = 0;      /* List of free configurations */
static struct config *current = 0;       /* Top of list of configurations */
static struct config **currentend = 0;   /* Last on list of configs */
static struct config *basis = 0;         /* Top of list of basis configs */
static struct config **basisend = 0;     /* End of list of basis configs */

/* Return a pointer to a new configuration */
PRIVATE struct config *newconfig(){
  struct config *new;
  if( freelist==0 ){
    int i;
    int amt = 3;
    freelist = (struct config *)calloc( amt, sizeof(struct config) );
    if( freelist==0 ){
      fprintf(stderr,"Unable to allocate memory for a new configuration.");
      exit(1);
    }
    for(i=0; i<amt-1; i++) freelist[i].next = &freelist[i+1];
    freelist[amt-1].next = 0;
  }
  new = freelist;
  freelist = freelist->next;
  return new;
}

/* The configuration "old" is no longer used */
PRIVATE void deleteconfig(old)
struct config *old;
{
  old->next = freelist;
  freelist = old;
}

/* Initialized the configuration list builder */
void Configlist_init(){
  current = 0;
  currentend = &current;
  basis = 0;
  basisend = &basis;
  Configtable_init();
  return;
}

/* Initialized the configuration list builder */
void Configlist_reset(){
  current = 0;
  currentend = &current;
  basis = 0;
  basisend = &basis;
  Configtable_clear(0);
  return;
}

/* Add another configuration to the configuration list */
struct config *Configlist_add(rp,dot)
struct rule *rp;    /* The rule */
int dot;            /* Index into the RHS of the rule where the dot goes */
{
  struct config *cfp, model;

  assert( currentend!=0 );
  model.rp = rp;
  model.dot = dot;
  cfp = Configtable_find(&model);
  if( cfp==0 ){
    cfp = newconfig();
    cfp->rp = rp;
    cfp->dot = dot;
    cfp->fws = SetNew();
    cfp->stp = 0;
    cfp->fplp = cfp->bplp = 0;
    cfp->next = 0;
    cfp->bp = 0;
    *currentend = cfp;
    currentend = &cfp->next;
    Configtable_insert(cfp);
  }
  return cfp;
}

/* Add a basis configuration to the configuration list */
struct config *Configlist_addbasis(rp,dot)
struct rule *rp;
int dot;
{
  struct config *cfp, model;

  assert( basisend!=0 );
  assert( currentend!=0 );
  model.rp = rp;
  model.dot = dot;
  cfp = Configtable_find(&model);
  if( cfp==0 ){
    cfp = newconfig();
    cfp->rp = rp;
    cfp->dot = dot;
    cfp->fws = SetNew();
    cfp->stp = 0;
    cfp->fplp = cfp->bplp = 0;
    cfp->next = 0;
    cfp->bp = 0;
    *currentend = cfp;
    currentend = &cfp->next;
    *basisend = cfp;
    basisend = &cfp->bp;
    Configtable_insert(cfp);
  }
  return cfp;
}

/* Compute the closure of the configuration list */
void Configlist_closure(lemp)
struct lemon *lemp;
{
  struct config *cfp, *newcfp;
  struct rule *rp, *newrp;
  struct symbol *sp, *xsp;
  int i, dot;

  assert( currentend!=0 );
  for(cfp=current; cfp; cfp=cfp->next){
    rp = cfp->rp;
    dot = cfp->dot;
    if( dot>=rp->nrhs ) continue;
    sp = rp->rhs[dot];
    if( sp->type==NONTERMINAL ){
      if( sp->rule==0 && sp!=lemp->errsym ){
        ErrorMsg(lemp->filename,rp->line,"Nonterminal \"%s\" has no rules.",
          sp->name);
        lemp->errorcnt++;
      }
      for(newrp=sp->rule; newrp; newrp=newrp->nextlhs){
        newcfp = Configlist_add(newrp,0);
        for(i=dot+1; i<rp->nrhs; i++){
          xsp = rp->rhs[i];
          if( xsp->type==TERMINAL ){
            SetAdd(newcfp->fws,xsp->index);
            break;
          }else if( xsp->type==MULTITERMINAL ){
            int k;
            for(k=0; k<xsp->nsubsym; k++){
              SetAdd(newcfp->fws, xsp->subsym[k]->index);
            }
            break;
	  }else{
            SetUnion(newcfp->fws,xsp->firstset);
            if( xsp->lambda==LEMON_FALSE ) break;
	  }
	}
        if( i==rp->nrhs ) Plink_add(&cfp->fplp,newcfp);
      }
    }
  }
  return;
}

/* Sort the configuration list */
void Configlist_sort(){
  current = (struct config *)msort((char *)current,(char **)&(current->next),Configcmp);
  currentend = 0;
  return;
}

/* Sort the basis configuration list */
void Configlist_sortbasis(){
  basis = (struct config *)msort((char *)current,(char **)&(current->bp),Configcmp);
  basisend = 0;
  return;
}

/* Return a pointer to the head of the configuration list and
** reset the list */
struct config *Configlist_return(){
  struct config *old;
  old = current;
  current = 0;
  currentend = 0;
  return old;
}

/* Return a pointer to the head of the configuration list and
** reset the list */
struct config *Configlist_basis(){
  struct config *old;
  old = basis;
  basis = 0;
  basisend = 0;
  return old;
}

/* Free all elements of the given configuration list */
void Configlist_eat(cfp)
struct config *cfp;
{
  struct config *nextcfp;
  for(; cfp; cfp=nextcfp){
    nextcfp = cfp->next;
    assert( cfp->fplp==0 );
    assert( cfp->bplp==0 );
    if( cfp->fws ) SetFree(cfp->fws);
    deleteconfig(cfp);
  }
  return;
}
/***************** From the file "error.c" *********************************/
/*
** Code for printing error message.
*/

/* Find a good place to break "msg" so that its length is at least "min"
** but no more than "max".  Make the point as close to max as possible.
*/
static int findbreak(msg,min,max)
char *msg;
int min;
int max;
{
  int i,spot;
  char c;
  for(i=spot=min; i<=max; i++){
    c = msg[i];
    if( c=='\t' ) msg[i] = ' ';
    if( c=='\n' ){ msg[i] = ' '; spot = i; break; }
    if( c==0 ){ spot = i; break; }
    if( c=='-' && i<max-1 ) spot = i+1;
    if( c==' ' ) spot = i;
  }
  return spot;
}

/*
** The error message is split across multiple lines if necessary.  The
** splits occur at a space, if there is a space available near the end
** of the line.
*/
#define ERRMSGSIZE  10000 /* Hope this is big enough.  No way to error check */
#define LINEWIDTH      79 /* Max width of any output line */
#define PREFIXLIMIT    30 /* Max width of the prefix on each line */
void ErrorMsg(const char *filename, int lineno, const char *format, ...){
  char errmsg[ERRMSGSIZE];
  char prefix[PREFIXLIMIT+10];
  int errmsgsize;
  int prefixsize;
  int availablewidth;
  va_list ap;
  int end, restart, base;

  va_start(ap, format);
  /* Prepare a prefix to be prepended to every output line */
  if( lineno>0 ){
    sprintf(prefix,"%.*s:%d: ",PREFIXLIMIT-10,filename,lineno);
  }else{
    sprintf(prefix,"%.*s: ",PREFIXLIMIT-10,filename);
  }
  prefixsize = lemonStrlen(prefix);
  availablewidth = LINEWIDTH - prefixsize;

  /* Generate the error message */
  vsprintf(errmsg,format,ap);
  va_end(ap);
  errmsgsize = lemonStrlen(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( lemonStrlen(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 int nolinenosflag = 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, "l", (char*)&nolinenosflag, "Do not print #line statements."},
    {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);
  }
  memset(&lem, 0, sizeof(lem));
  lem.errorcnt = 0;

  /* Initialize the machine */
  Strsafe_init();
  Symbol_init();
  State_init();
  lem.argv0 = argv[0];
  lem.filename = OptArg(0);
  lem.basisflag = basisflag;
  lem.nolinenosflag = nolinenosflag;
  Symbol_new("$");
  lem.errsym = Symbol_new("error");
  lem.errsym->useCnt = 0;

  /* Parse the input file */
  Parse(&lem);
  if( lem.errorcnt ) exit(lem.errorcnt);
  if( lem.nrule==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+1);

    /* 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);

    /* Reorder and renumber the states so that states with fewer choices
    ** occur at the end. */
    ResortStates(&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:
** …