lemon.c

SQLite 2.8.6 源代码,用来在Linux/Unix/Windows上编译安装.它是一个小型的数据库,但是非常好用,速度也快,一般的数据库查询之类的操作据统计比MySQL,PostgreSQL

    RHS_ALIAS_1,
    RHS_ALIAS_2,
    PRECEDENCE_MARK_1,
    PRECEDENCE_MARK_2,
    RESYNC_AFTER_RULE_ERROR,
    RESYNC_AFTER_DECL_ERROR,
    WAITING_FOR_DESTRUCTOR_SYMBOL,
    WAITING_FOR_DATATYPE_SYMBOL,
    WAITING_FOR_FALLBACK_ID
  } state;                   /* The state of the parser */
  struct symbol *fallback;   /* The fallback token */
  struct symbol *lhs;        /* Left-hand side of current rule */
  char *lhsalias;            /* Alias for the LHS */
  int nrhs;                  /* Number of right-hand side symbols seen */
  struct symbol *rhs[MAXRHS];  /* RHS symbols */
  char *alias[MAXRHS];       /* Aliases for each RHS symbol (or NULL) */
  struct rule *prevrule;     /* Previous rule parsed */
  char *declkeyword;         /* Keyword of a declaration */
  char **declargslot;        /* Where the declaration argument should be put */
  int *decllnslot;           /* Where the declaration linenumber is put */
  enum e_assoc declassoc;    /* Assign this association to decl arguments */
  int preccounter;           /* Assign this precedence to decl arguments */
  struct rule *firstrule;    /* Pointer to first rule in the grammar */
  struct rule *lastrule;     /* Pointer to the most recently parsed rule */
};

/* Parse a single token */
static void parseonetoken(psp)
struct pstate *psp;
{
  char *x;
  x = Strsafe(psp->tokenstart);     /* Save the token permanently */
#if 0
  printf("%s:%d: Token=[%s] state=%d\n",psp->filename,psp->tokenlineno,
    x,psp->state);
#endif
  switch( psp->state ){
    case INITIALIZE:
      psp->prevrule = 0;
      psp->preccounter = 0;
      psp->firstrule = psp->lastrule = 0;
      psp->gp->nrule = 0;
      /* Fall thru to next case */
    case WAITING_FOR_DECL_OR_RULE:
      if( x[0]=='%' ){
        psp->state = WAITING_FOR_DECL_KEYWORD;
      }else if( islower(x[0]) ){
        psp->lhs = Symbol_new(x);
        psp->nrhs = 0;
        psp->lhsalias = 0;
        psp->state = WAITING_FOR_ARROW;
      }else if( x[0]=='{' ){
        if( psp->prevrule==0 ){
          ErrorMsg(psp->filename,psp->tokenlineno,
"There is not prior rule opon which to attach the code \
fragment which begins on this line.");
          psp->errorcnt++;
	}else if( psp->prevrule->code!=0 ){
          ErrorMsg(psp->filename,psp->tokenlineno,
"Code fragment beginning on this line is not the first \
to follow the previous rule.");
          psp->errorcnt++;
        }else{
          psp->prevrule->line = psp->tokenlineno;
          psp->prevrule->code = &x[1];
	}
      }else if( x[0]=='[' ){
        psp->state = PRECEDENCE_MARK_1;
      }else{
        ErrorMsg(psp->filename,psp->tokenlineno,
          "Token \"%s\" should be either \"%%\" or a nonterminal name.",
          x);
        psp->errorcnt++;
      }
      break;
    case PRECEDENCE_MARK_1:
      if( !isupper(x[0]) ){
        ErrorMsg(psp->filename,psp->tokenlineno,
          "The precedence symbol must be a terminal.");
        psp->errorcnt++;
      }else if( psp->prevrule==0 ){
        ErrorMsg(psp->filename,psp->tokenlineno,
          "There is no prior rule to assign precedence \"[%s]\".",x);
        psp->errorcnt++;
      }else if( psp->prevrule->precsym!=0 ){
        ErrorMsg(psp->filename,psp->tokenlineno,
"Precedence mark on this line is not the first \
to follow the previous rule.");
        psp->errorcnt++;
      }else{
        psp->prevrule->precsym = Symbol_new(x);
      }
      psp->state = PRECEDENCE_MARK_2;
      break;
    case PRECEDENCE_MARK_2:
      if( x[0]!=']' ){
        ErrorMsg(psp->filename,psp->tokenlineno,
          "Missing \"]\" on precedence mark.");
        psp->errorcnt++;
      }
      psp->state = WAITING_FOR_DECL_OR_RULE;
      break;
    case WAITING_FOR_ARROW:
      if( x[0]==':' && x[1]==':' && x[2]=='=' ){
        psp->state = IN_RHS;
      }else if( x[0]=='(' ){
        psp->state = LHS_ALIAS_1;
      }else{
        ErrorMsg(psp->filename,psp->tokenlineno,
          "Expected to see a \":\" following the LHS symbol \"%s\".",
          psp->lhs->name);
        psp->errorcnt++;
        psp->state = RESYNC_AFTER_RULE_ERROR;
      }
      break;
    case LHS_ALIAS_1:
      if( isalpha(x[0]) ){
        psp->lhsalias = x;
        psp->state = LHS_ALIAS_2;
      }else{
        ErrorMsg(psp->filename,psp->tokenlineno,
          "\"%s\" is not a valid alias for the LHS \"%s\"\n",
          x,psp->lhs->name);
        psp->errorcnt++;
        psp->state = RESYNC_AFTER_RULE_ERROR;
      }
      break;
    case LHS_ALIAS_2:
      if( x[0]==')' ){
        psp->state = LHS_ALIAS_3;
      }else{
        ErrorMsg(psp->filename,psp->tokenlineno,
          "Missing \")\" following LHS alias name \"%s\".",psp->lhsalias);
        psp->errorcnt++;
        psp->state = RESYNC_AFTER_RULE_ERROR;
      }
      break;
    case LHS_ALIAS_3:
      if( x[0]==':' && x[1]==':' && x[2]=='=' ){
        psp->state = IN_RHS;
      }else{
        ErrorMsg(psp->filename,psp->tokenlineno,
          "Missing \"->\" following: \"%s(%s)\".",
           psp->lhs->name,psp->lhsalias);
        psp->errorcnt++;
        psp->state = RESYNC_AFTER_RULE_ERROR;
      }
      break;
    case IN_RHS:
      if( x[0]=='.' ){
        struct rule *rp;
        rp = (struct rule *)malloc( sizeof(struct rule) + 
             sizeof(struct symbol*)*psp->nrhs + sizeof(char*)*psp->nrhs );
        if( rp==0 ){
          ErrorMsg(psp->filename,psp->tokenlineno,
            "Can't allocate enough memory for this rule.");
          psp->errorcnt++;
          psp->prevrule = 0;
	}else{
          int i;
          rp->ruleline = psp->tokenlineno;
          rp->rhs = (struct symbol**)&rp[1];
          rp->rhsalias = (char**)&(rp->rhs[psp->nrhs]);
          for(i=0; i<psp->nrhs; i++){
            rp->rhs[i] = psp->rhs[i];
            rp->rhsalias[i] = psp->alias[i];
	  }
          rp->lhs = psp->lhs;
          rp->lhsalias = psp->lhsalias;
          rp->nrhs = psp->nrhs;
          rp->code = 0;
          rp->precsym = 0;
          rp->index = psp->gp->nrule++;
          rp->nextlhs = rp->lhs->rule;
          rp->lhs->rule = rp;
          rp->next = 0;
          if( psp->firstrule==0 ){
            psp->firstrule = psp->lastrule = rp;
	  }else{
            psp->lastrule->next = rp;
            psp->lastrule = rp;
	  }
          psp->prevrule = rp;
	}
        psp->state = WAITING_FOR_DECL_OR_RULE;
      }else if( isalpha(x[0]) ){
        if( psp->nrhs>=MAXRHS ){
          ErrorMsg(psp->filename,psp->tokenlineno,
            "Too many symbol on RHS or rule beginning at \"%s\".",
            x);
          psp->errorcnt++;
          psp->state = RESYNC_AFTER_RULE_ERROR;
	}else{
          psp->rhs[psp->nrhs] = Symbol_new(x);
          psp->alias[psp->nrhs] = 0;
          psp->nrhs++;
	}
      }else if( x[0]=='(' && psp->nrhs>0 ){
        psp->state = RHS_ALIAS_1;
      }else{
        ErrorMsg(psp->filename,psp->tokenlineno,
          "Illegal character on RHS of rule: \"%s\".",x);
        psp->errorcnt++;
        psp->state = RESYNC_AFTER_RULE_ERROR;
      }
      break;
    case RHS_ALIAS_1:
      if( isalpha(x[0]) ){
        psp->alias[psp->nrhs-1] = x;
        psp->state = RHS_ALIAS_2;
      }else{
        ErrorMsg(psp->filename,psp->tokenlineno,
          "\"%s\" is not a valid alias for the RHS symbol \"%s\"\n",
          x,psp->rhs[psp->nrhs-1]->name);
        psp->errorcnt++;
        psp->state = RESYNC_AFTER_RULE_ERROR;
      }
      break;
    case RHS_ALIAS_2:
      if( x[0]==')' ){
        psp->state = IN_RHS;
      }else{
        ErrorMsg(psp->filename,psp->tokenlineno,
          "Missing \")\" following LHS alias name \"%s\".",psp->lhsalias);
        psp->errorcnt++;
        psp->state = RESYNC_AFTER_RULE_ERROR;
      }
      break;
    case WAITING_FOR_DECL_KEYWORD:
      if( isalpha(x[0]) ){
        psp->declkeyword = x;
        psp->declargslot = 0;
        psp->decllnslot = 0;
        psp->state = WAITING_FOR_DECL_ARG;
        if( strcmp(x,"name")==0 ){
          psp->declargslot = &(psp->gp->name);
	}else if( strcmp(x,"include")==0 ){
          psp->declargslot = &(psp->gp->include);
          psp->decllnslot = &psp->gp->includeln;
	}else if( strcmp(x,"code")==0 ){
          psp->declargslot = &(psp->gp->extracode);
          psp->decllnslot = &psp->gp->extracodeln;
	}else if( strcmp(x,"token_destructor")==0 ){
          psp->declargslot = &psp->gp->tokendest;
          psp->decllnslot = &psp->gp->tokendestln;
	}else if( strcmp(x,"default_destructor")==0 ){
          psp->declargslot = &psp->gp->vardest;
          psp->decllnslot = &psp->gp->vardestln;
	}else if( strcmp(x,"token_prefix")==0 ){
          psp->declargslot = &psp->gp->tokenprefix;
	}else if( strcmp(x,"syntax_error")==0 ){
          psp->declargslot = &(psp->gp->error);
          psp->decllnslot = &psp->gp->errorln;
	}else if( strcmp(x,"parse_accept")==0 ){
          psp->declargslot = &(psp->gp->accept);
          psp->decllnslot = &psp->gp->acceptln;
	}else if( strcmp(x,"parse_failure")==0 ){
          psp->declargslot = &(psp->gp->failure);
          psp->decllnslot = &psp->gp->failureln;
	}else if( strcmp(x,"stack_overflow")==0 ){
          psp->declargslot = &(psp->gp->overflow);
          psp->decllnslot = &psp->gp->overflowln;
        }else if( strcmp(x,"extra_argument")==0 ){
          psp->declargslot = &(psp->gp->arg);
        }else if( strcmp(x,"token_type")==0 ){
          psp->declargslot = &(psp->gp->tokentype);
        }else if( strcmp(x,"default_type")==0 ){
          psp->declargslot = &(psp->gp->vartype);
        }else if( strcmp(x,"stack_size")==0 ){
          psp->declargslot = &(psp->gp->stacksize);
        }else if( strcmp(x,"start_symbol")==0 ){
          psp->declargslot = &(psp->gp->start);
        }else if( strcmp(x,"left")==0 ){
          psp->preccounter++;
          psp->declassoc = LEFT;
          psp->state = WAITING_FOR_PRECEDENCE_SYMBOL;
        }else if( strcmp(x,"right")==0 ){
          psp->preccounter++;
          psp->declassoc = RIGHT;
          psp->state = WAITING_FOR_PRECEDENCE_SYMBOL;
        }else if( strcmp(x,"nonassoc")==0 ){
          psp->preccounter++;
          psp->declassoc = NONE;
          psp->state = WAITING_FOR_PRECEDENCE_SYMBOL;
	}else if( strcmp(x,"destructor")==0 ){
          psp->state = WAITING_FOR_DESTRUCTOR_SYMBOL;
	}else if( strcmp(x,"type")==0 ){
          psp->state = WAITING_FOR_DATATYPE_SYMBOL;
        }else if( strcmp(x,"fallback")==0 ){
          psp->fallback = 0;
          psp->state = WAITING_FOR_FALLBACK_ID;
        }else{
          ErrorMsg(psp->filename,psp->tokenlineno,
            "Unknown declaration keyword: \"%%%s\".",x);
          psp->errorcnt++;
          psp->state = RESYNC_AFTER_DECL_ERROR;
	}
      }else{
        ErrorMsg(psp->filename,psp->tokenlineno,
          "Illegal declaration keyword: \"%s\".",x);
        psp->errorcnt++;
        psp->state = RESYNC_AFTER_DECL_ERROR;
      }
      break;
    case WAITING_FOR_DESTRUCTOR_SYMBOL:
      if( !isalpha(x[0]) ){
        ErrorMsg(psp->filename,psp->tokenlineno,
          "Symbol name missing after %destructor keyword");
        psp->errorcnt++;
        psp->state = RESYNC_AFTER_DECL_ERROR;
      }else{
        struct symbol *sp = Symbol_new(x);
        psp->declargslot = &sp->destructor;
        psp->decllnslot = &sp->destructorln;
        psp->state = WAITING_FOR_DECL_ARG;
      }
      break;
    case WAITING_FOR_DATATYPE_SYMBOL:
      if( !isalpha(x[0]) ){
        ErrorMsg(psp->filename,psp->tokenlineno,
          "Symbol name missing after %destructor keyword");
        psp->errorcnt++;
        psp->state = RESYNC_AFTER_DECL_ERROR;
      }else{
        struct symbol *sp = Symbol_new(x);
        psp->declargslot = &sp->datatype;
        psp->decllnslot = 0;
        psp->state = WAITING_FOR_DECL_ARG;
      }
      break;
    case WAITING_FOR_PRECEDENCE_SYMBOL:
      if( x[0]=='.' ){
        psp->state = WAITING_FOR_DECL_OR_RULE;
      }else if( isupper(x[0]) ){
        struct symbol *sp;
        sp = Symbol_new(x);
        if( sp->prec>=0 ){
          ErrorMsg(psp->filename,psp->tokenlineno,
            "Symbol \"%s\" has already be given a precedence.",x);
          psp->errorcnt++;
	}else{
          sp->prec = psp->preccounter;
          sp->assoc = psp->declassoc;
	}
      }else{
        ErrorMsg(psp->filename,psp->tokenlineno,
          "Can't assign a precedence to \"%s\".",x);
        psp->errorcnt++;
      }
      break;
    case WAITING_FOR_DECL_ARG:
      if( (x[0]=='{' || x[0]=='\"' || isalnum(x[0])) ){
        if( *(psp->declargslot)!=0 ){
          ErrorMsg(psp->filename,psp->tokenlineno,
            "The argument \"%s\" to declaration \"%%%s\" is not the first.",
            x[0]=='\"' ? &x[1] : x,psp->declkeyword);
          psp->errorcnt++;
          psp->state = RESYNC_AFTER_DECL_ERROR;
	}else{
          *(psp->declargslot) = (x[0]=='\"' || x[0]=='{') ? &x[1] : x;
          if( psp->decllnslot ) *psp->decllnslot = psp->tokenlineno;
          psp->state = WAITING_FOR_DECL_OR_RULE;
	}
      }else{
        ErrorMsg(psp->filename,psp->tokenlineno,
          "Illegal argument to %%%s: %s",psp->declkeyword,x);
        psp->errorcnt++;
        psp->state = RESYNC_AFTER_DECL_ERROR;
      }
      break;
    case WAITING_FOR_FALLBACK_ID:
      if( x[0]=='.' ){
        psp->state = WAITING_FOR_DECL_OR_RULE;
      }else if( !isupper(x[0]) ){
        ErrorMsg(psp->filename, psp->tokenlineno,
          "%%fallback argument \"%s\" should be a token", x);
        psp->errorcnt++;
      }else{
        struct symbol *sp = Symbol_new(x);
        if( psp->fallback==0 ){
          psp->fallback = sp;
        }else if( sp->fallback ){
          ErrorMsg(psp->filename, psp->tokenlineno,
            "More than one fallback assigned to token %s", x);
          psp->errorcnt++;
        }else{
          sp->fallback = psp->fallback;
          psp->gp->has_fallback = 1;
        }
      }
      break;
    case RESYNC_AFTER_RULE_ERROR:
/*      if( x[0]=='.' ) psp->state = WAITING_FOR_DECL_OR_RULE;
**      break; */
    case RESYNC_AFTER_DECL_ERROR:
      if( x[0]=='.' ) psp->state = WAITING_FOR_DECL_OR_RULE;
      if( x[0]=='%' ) psp->state = WAITING_FOR_DECL_KEYWORD;
      break;
  }
}

/* In spite of its name, this function is really a scanner.  It read
** in the entire input file (all at once) then tokenizes it.  Each
** token is passed to the function "parseonetoken" which builds all
** the appropriate data structures in the global state vector "gp".
*/
void Parse(gp)
struct lemon *gp;
{
  struct pstate ps;
  FILE *fp;
  char *filebuf;
  int filesize;
  int lineno;
  int c;
  char *cp, *nextcp;
  int startline = 0;

  ps.gp = gp;
  ps.filename = gp->filename;
  ps.errorcnt = 0;
  ps.state = INITIALIZE;

  /* Begin by reading the input file