Ejemplo n.º 1
0
/*
Purpose: Installs a new entry (VID record) in the symbol table.
Authors: Kwok Hong Kelvin Chan, Kyle Hinskens
Version: 13.11.14
Called functions: st_lookup(), b_setmark(), b_getsize(), strlen(), b_addc(), printf(),
				b_get_r_flag(), b_get_chmemloc(), b_getmark(), st_incoffset()
Parameters:
			STD sym_table The symbol table
			char *lexeme The lexeme
			int line The line number
Return value: int The offset of the lexeme or -1 on error
*/
int st_install(STD sym_table, char *lexeme, int line) {
	int offset; /* lookup() return value*/
	unsigned int i; /* loop counter for strlen */
	int j; /* loop counter */
	unsigned short buffer_offset = 0; /* buffer_offset, used for reorganize plex on the symbol table */

	offset = st_lookup(sym_table, lexeme);

	/* check if the symbol table is full */
	if (sym_table.st_offset == sym_table.st_size) return R_FAIL_1;

	/* lexeme is not found from the symbol table */ 
	if (offset == -1) {
		b_setmark(sym_table.plsBD, b_getsize(sym_table.plsBD)); /* set mark on the Buffer at the addc_offset index */
		/* store lexeme into the symbol table Buffer */
		for (i = 0; i < strlen(lexeme) + 1; ++i) {
			/* check if b_addc() executed successfully, just in case! */
			if (b_addc(sym_table.plsBD, lexeme[i]) == NULL) {
				return R_FAIL_2;
			}

			/* Buffer reallocation, reorganize plex on the symbol table */
			if (b_get_r_flag(sym_table.plsBD)) {
				/* traverse the symbol table, and reassign the correct memory address from the new Buffer */
				 for (j = 0; j < sym_table.st_offset; ++j) {
					sym_table.pstvr[j].plex = b_get_chmemloc(sym_table.plsBD, buffer_offset); /* get the character pointer from the buffer_offset */
					buffer_offset += (unsigned short)strlen(b_get_chmemloc(sym_table.plsBD, buffer_offset)) + 1; /* increment buffer_offset by the strlen from current string  */
				}
			}
		}

		sym_table.pstvr[sym_table.st_offset].plex = b_get_chmemloc(sym_table.plsBD, b_getmark(sym_table.plsBD)); /* set plex as the beginning of the lexeme from the Buffer */
		sym_table.pstvr[sym_table.st_offset].o_line = line; /* set line number */
		sym_table.pstvr[sym_table.st_offset].status_field = DEFAULT; /* set default status field */

		/* variable of type string */ 
		if (lexeme[strlen(lexeme) -1] == '#') {
			sym_table.pstvr[sym_table.st_offset].status_field |= STRING_MASK; /* set status field as string by performing a OR operation with the STRING_MASK */
			sym_table.pstvr[sym_table.st_offset].status_field |= UPDATE_MASK; /* Set update flag */
			sym_table.pstvr[sym_table.st_offset].i_value.str_offset = -1; /* set i_value */
		}
		/* variable of type int */ 
		else if (lexeme[0] == 'i' || lexeme[0] == 'o' || lexeme[0] == 'd' || lexeme[0] == 'n') {
			sym_table.pstvr[sym_table.st_offset].status_field |= INT_MASK; /* set status field as int by performing a OR operation with the INT_MASK*/
			sym_table.pstvr[sym_table.st_offset].i_value.int_val = 0; /* set i_value */
		}
		/* variable of type float */ 
		else {
			sym_table.pstvr[sym_table.st_offset].status_field |= FLOAT_MASK; /* set status field as float by performing a OR operation with the FLOAT_MASK*/
			sym_table.pstvr[sym_table.st_offset].i_value.fpl_val = 0.0f; /* set i_value */
		}

		st_incoffset(); /* increment global symbol table st_offset field */
		return sym_table.st_offset; /* The function returns the current offset of that entry from the beginning of the array of STVR (the array pointed by pstvr). */
	}

	return offset;
}
Ejemplo n.º 2
0
/**********************************************************************************************************
Purpose:			Set the proper token depending on the lexeme read from the buffer. 
Author:				Thom Palmer and Chris Whitten
History/Versions:	10.20.13
Called functions:	b_setmark(), b_getc(), b_getmark(), SEOF(), WHTSPACE(), is_assop(), strncmp(),
					b_set_getc_offset(), b_retract(), b_get_getc_offset(),b_eob(), isalnum(), b_addc()
					get_next_state(), b_create(), b_pack(), b_destroy() 
Parameters:			Buffer * const pBD
Return value:		Token t
Algorithm:			Validate parameters, read char from buffer, check the char to see if its a legal character.
					depending on the char peak forward to see what the following char is in order to 
					determine if it's part of the lexeme or if it's time to return. once a valid lexeme is
					found set the token and return. if a valid lexeme is not found set the token to error 
					state and return. 
**********************************************************************************************************/
Token mlwpar_next_token(Buffer * sc_buf)
{
	Token t;			/* token to return after recognition */
	unsigned char c;	/* input symbol */
	int state = 0;		/* initial state of the FSM */
	unsigned int retrCtr;
	short lexstart;		/* start offset of a lexeme in the input buffer */
	short lexend;		/* end offset of a lexeme in the input buffer */
	int accept = NOAS;	/* type of state - initially not accepting */  
	unsigned int i=0;	/* Used throughout the function as iterator */
   
	/* Ensure the buffer is not null before trying to access it */

	if(sc_buf == NULL)
	{	   
		scerrnum = BUFFNULL;  
	     t_set_err_t(RUNTIMERR, t);
	}     
                
	while (1) /* Endless loop broken by token returns it will generate a warning */
	{ 
                
		/* Set mark before getting the next character. This prevents the need for unneccessary decrements. */
		b_setmark(sc_buf, b_get_getc_offset(sc_buf));
		lexstart = b_getmark(sc_buf);
	
		/* Get the next char from the buffer. */
		c = b_getc(sc_buf); 	
	
		/* Ensure SEOF has not been read before processing any further. */
		if(SEOF(c))
		{
			t.code = SEOF_T;
			return t;
		}

		/* If it's whitespace ignore and return to the start of the loop. */
		if(WHTSPC(c))
		{
			continue;
		}

		/* Drop into switch statement to determine what the character can potentially represent and handle it appropriatly. */
		switch(c)
		{
			/* If c is '=' the token can either be a relation operatory or an assignment operator,  so peak forward */
			case EQSIGN:
				{ 
					c = b_getc(sc_buf);
					/* If the next character is '=' then we have found a relational operator */
					if(c == EQSIGN) 
					{
						/* Set the code and attribute and return t */
						t.code = REL_OP_T;
						t.attribute.rel_op = EQ;
						return t;
					}
					/* Otherwise retract and return an assignment operator token */
					b_retract(sc_buf);
					t.code = ASS_OP_T;
					return t;
				} 
			/* If the token starts with ! it can either be a comment or the != relational operator, so peak forward and act appropriatly. */
			case EXCLAMTN:
				c = b_getc(sc_buf);
				/* If the next token is < then we have a comment therfore ignore everything in the line.*/
				if(c == LESSTHN)
				{
					do
					{
						c = b_getc(sc_buf);
						if(SEOF(c))
						{ 
							t.code = ERR_T;
							t.attribute.err_lex[0] = EXCLAMTN;
							t.attribute.err_lex[1] = LESSTHN;
							t.attribute.err_lex[2] = c;
							t.attribute.err_lex[3] = STRTERM;
							b_retract(sc_buf);
							return t;
						}
					}while ( c != NEWLINE && c != CARRTRN);

					++line;
					continue;
				}
				/* If the next token we have the NE relational operator. */
				if(c == EQSIGN)
				{
					t.code = REL_OP_T;
					t.attribute.rel_op = NE ;
					return t;
				}
				/* if the next char is neither = or < we have an error set ERR_T*/
				t.code = ERR_T;
				t.attribute.err_lex[0] = EXCLAMTN;
				t.attribute.err_lex[1] = c;
				t.attribute.err_lex[2] = STRTERM;
	   
				/* We assume the error was meant to be a token so ignore everything in the line. */
				do
				{
					c = b_getc(sc_buf);
					/* If SEOF or b_eob is found retract the buffer and return t */
					if(SEOF(c))
					{
						b_retract(sc_buf);
						return t;
					}
				}while ( c != NEWLINE);
				++line;
				return t;

			/*If we have a plus sign '+' set the token and it's attirbute then return. */
			case POS:
				t.code = ART_OP_T;
				t.attribute.arr_op = PLUS;
				return t;

			/*If we have a minus sign '-' set the token and it's attirbute then return. */
			case NEG:
				t.code = ART_OP_T;
				t.attribute.arr_op = MINUS;
				return t;

			/*If we have a a period '.' it could be a logical operator or an error. */
			case PERIOD:
				retrCtr = 1;
				i = 0;
				c = b_getc(sc_buf);
				
				/* Switch on the first character read after the period '.' */
				switch (c) 
				{
				/* If its an 'A' we might have .AND. */
				case'A' :
					/* Compare the string the string read from the buffer to the string literal .AND.  */
					++retrCtr;
					if(b_getc(sc_buf) == 'N')
					{
						++retrCtr;
						if(b_getc(sc_buf) == 'D')
						{
							++retrCtr;
							if(b_getc(sc_buf) == PERIOD)
							{
								t.code = LOG_OP_T;
								t.attribute.log_op = AND;
								return t;
							}
						}
					}
					break;
				case'O':
					/* Comapre the string the string read from the buffer to the string literal .OR.  */
					++retrCtr;
					if(b_getc(sc_buf) == 'R')
					{
						++retrCtr;
						if(b_getc(sc_buf) == PERIOD)
						{
							t.code = LOG_OP_T;
							t.attribute.log_op = OR;
							return t;
						}
					}

					break;
				}

				while(i<retrCtr)
				{
					b_retract(sc_buf);
					i++;
				}
				t.code = ERR_T;
				/* Add char which caused the error to the err_lex */
				t.attribute.err_lex[0] = PERIOD;
				t.attribute.err_lex[1] = STRTERM;
				return t;

			/* If we have an astrix sign '*' set the token and it's attirbute then return. */
			case ASTRX:
				t.code = ART_OP_T;
				t.attribute.arr_op = MULT;
				return t;

			/* If c is a forward slash '/' set the token and it's attirbute then return. */
			case FWDSLSH:
				t.code = ART_OP_T;
				t.attribute.arr_op = DIV;
				return t;

			/* If c is a left brace '{' set the token and it's attirbute then return. */
			case LBRACE:
				t.code = LBR_T;
				return t;

			/* If c is a right brace '}' set the token and it's attirbute then return. */
			case RBRACE:
				t.code = RBR_T;
				return t;

			/* If c is a left parenthesis '(' set the token and it's attirbute then return. */
			case LPRNTHS:
				t.code = LPR_T;
				return t;

			/* If c is a right parenthesis ')' set the token and it's attirbute then return. */
			case RPRNTHS:
				t.code = RPR_T;
				return t;

			/* If c is a less than symbol '<' check the next char. */
			case LESSTHN:
				c = b_getc(sc_buf);

				/* If the next char is the greater than symbol '>' set the proper token and return. */
				if(c == GRTRTHN){
					t.code = SCC_OP_T;
					return t;
				}

				/* If the next char is not recognized restract the buffer and set the token */
				t.code = REL_OP_T;
				t.attribute.rel_op = LT;
				b_retract(sc_buf);
				return t;

			/* If c is a greater than symbol '>' set the proper token and return. */
			case GRTRTHN:
				t.code = REL_OP_T;
				t.attribute.rel_op = GT;
				return t;

			/* If c is a new line '\n' increment the line number and return to the start of the loop. */
			case CARRTRN:
				NEWLINE_TEST
				continue;
				
			/* If c is a NEWLINE character increment the line number and continue */
			case NEWLINE:
				++line;
				continue;

			/* If c is a comma ',' set the proper token and return. */
			case COMMA:
				t.code = COM_T;  
				return t;

			/* If c is a semi colon ';' set the proper token and return. */
			case SEMICLN:
				t.code = EOS_T;
				return t;

			/* If c is a quotation mark '"' we have the start of a string, analyze the next chars until '"' or SEOF is hit. */
			case QUOTE:
				/* read all the chars in from the input buffer until a '"' */
				do
				{
					c = b_getc(sc_buf);
					lexend = b_get_getc_offset(sc_buf);
					/* If eob has be set or SEOF is read in from the buffer prior to closing the string */
					/* Break into the error token setup. */
					if( SEOF(c))
					{	
						/* Set the getc_offset to the start of the string */
						b_set_getc_offset(sc_buf,lexstart);
						/* Iterate over the buffer and copy the contents of the error string into the err_lex */
						for( i = 0; i < lexend-lexstart; i++) /* Comparison of unsigned int and short will generate warning. 
															     lexend-lexstart will always be positive no need to cast */
						{				
							c = b_getc(sc_buf);
							/* For the first 20 characters */
							if(i<=ERR_LEN)
							{
								/* Copy c into the current index of err_lex for first 16 characters */
								if(i<=16)
								t.attribute.err_lex[i] = c;
								/* Copy a decimal into the indexes between 17 and ERR_LEN */
								if(i>16 && i<ERR_LEN)
								{
									t.attribute.err_lex[i] = PERIOD;
								}
								/* Copy a string terminator into the last index of err_lex */
								if (i==ERR_LEN)
								{
									t.attribute.err_lex[i]= STRTERM;
								}

							}
					
						}
						t.code = ERR_T;							
						return t;
					}
					/* Increment the line number each time a line terminator is found */
					if(c == NEWLINE)
					{
						++line;
					}
					if(c == CARRTRN)
					{
						NEWLINE_TEST
					}
				}while ( c != QUOTE );
			
				/* Closing quote found. Valid String */
				/* Set the getc_offset back to the start of the string */
				b_set_getc_offset(sc_buf,lexstart);
				/* Set the str_offset attribute to the location of the current getc_offset in the str_LTBL */
				t.attribute.str_offset = b_getsize(str_LTBL);

				/* Add the characters of the string into the str_LTBL */
				for(  i = 0; i< lexend-lexstart;i++) /* Comparison of unsigned int and short will generate warning. 
														lexend-lexstart will always be positive no need to cast */
				{			
					c = b_getc(sc_buf);
					/* Ensure that quotes are not added to the string */
					if(c != '"')
					{
						if(!b_addc(str_LTBL, c))
						{
							scerrnum = FAILADDC;
							t_set_err_t(RUNTIMERR, t);
						}
					}
				}
				/* Add the string terminator to the string and set the Token Code */
				if (!b_addc(str_LTBL,STRTERM))
				{
					scerrnum = FAILADDC;
					t_set_err_t(RUNTIMERR, t);
				}
				t.code = STR_T;
				return t;
			}
	
		/* Special symbol scanning completed. Now checking for lexeme type */
		if (isalnum(c))
		{
			/* Use for loop to iterate over the transition table based on the current state and character */
			/* Continue iterating until an accepting state has been found */
			for(state = get_next_state(state,c,&accept);accept==NOAS; state = get_next_state(state,c,&accept))
			{
				c = b_getc(sc_buf);
			}
		
			/* Retract the buffer if is is an accepting state with a retract */
			if(accept==ASWR)
			{
				b_retract(sc_buf);
			}
			/* Set the end of the lexeme at the current getc_offset */
			lexend = b_get_getc_offset(sc_buf);
			/* Create a temporary buffer to store the lexeme */
			lex_buf = b_create((lexend - lexstart +1),0,'f');
			/* If buffer creation was not successful. Set the error token for a runtime error. */
			if (!lex_buf)
			{
				scerrnum = BUFFNULL;
				t_set_err_t(RUNTIMERR, t);
			}

			
			
			/* Reset the getc_offset to the start of the lexeme */
			b_set_getc_offset(sc_buf,lexstart);
			/* Add the characters of the lexeme to lex_buf */
			for( i = 0;i<lexend-lexstart;i++) /* Comparison of unsigned int and short will generate warning. 
												 lexend-lexstart will always be positive no need to cast */
			{
				if (!b_addc(lex_buf,b_getc(sc_buf)))
				{
					scerrnum = FAILADDC;
					t_set_err_t(RUNTIMERR, t);
				}
			}
			/* Pack lex_buf and add the string terminator to it */
			b_pack(lex_buf);
			/* If b_addc fails set the token for a runtime error and return t  */
			if (!b_addc(lex_buf,STRTERM))
			{
				scerrnum = FAILADDC;
				t_set_err_t(RUNTIMERR, t);
			}
			/* Call the accepting function at the current state index and pass the lexeme */
			t = aa_table[state](b_get_chmemloc(lex_buf,0));
			b_destroy(lex_buf);
			return t;
		}
		/* This code will be executed if c was an invalid symbol*/
		/* Set error token and return t. */
		t.code = ERR_T;
		t.attribute.err_lex[0] = c;
		t.attribute.err_lex[1] = STRTERM; /*Probably a better way to do this.*/
		return t;             
   }
}
Ejemplo n.º 3
0
int main(int argc, char **argv){

	Buffer *ptr_Buffer;   /* pointer to Buffer structure */
	FILE *fi;             /* input file handle */
	int loadsize = 0;     /*the size of the file loaded in the buffer */
	int ansi_c = !ANSI_C; /* ANSI C compliancy flag */

	/* Check if the compiler option is set to compile ANSI C */
	/* __DATE__, __TIME__, __LINE__, __FILE__, __STDC__ are predefined preprocessor macros*/
	if (ansi_c){
		err_printf("Date: %s  Time: %s", __DATE__, __TIME__);
		err_printf("ERROR: Compiler is not ANSI C compliant!\n");
		exit(1);
	}

	/* missing file name or/and mode parameter */
	if (argc <= 2){

		err_printf("\nDate: %s  Time: %s", __DATE__, __TIME__);
		err_printf("\nRuntime error at line %d in file %s\n", __LINE__, __FILE__);
		err_printf("%s\b\b\b\b%s%s", argv[0], ": ", "Missing parameters.");
		err_printf("Usage: platybt source_file_name mode");
		exit(1);
	}

	/* create a source code input buffer */
	switch (*argv[2]){ /*gets the first caracter of the mode argument*/
	case 'f': case 'a': case 'm': break;
	default:
		err_printf("%s%s%s", argv[0], ": ", "Wrong mode parameter.");
		exit(1);
	}
	/*create the input buffer */
	ptr_Buffer = b_create(INIT_CAPACITY, INC_FACTOR, *argv[2]);
	if (ptr_Buffer == NULL){
		err_printf("%s%s%s", argv[0], ": ", "Could not create buffer.");
		exit(1);
	}

	/* open the source file */
	if ((fi = fopen(argv[1], "r")) == NULL){
		err_printf("%s%s%s%s", argv[0], ": ", "Cannot open file: ", argv[1]);
		exit(1);
	}

	/* load a source file into the input buffer  */
	printf("Reading file %s ....Please wait\n", argv[1]);
	loadsize = b_load(fi, ptr_Buffer);
	if (loadsize == R_FAIL_1)
		err_printf("%s%s%s", argv[0], ": ", "Error in loading buffer.");

	/* close the source file */
	fclose(fi);
	/*find the size of the file  */
	if (loadsize == LOAD_FAIL){
		printf("The input file %s %s\n", argv[1], "is not completely loaded.");
		printf("Input file size: %ld\n", get_filesize(argv[1]));
	}
	/* set a mark at the last char in the buffer*/
	b_setmark(ptr_Buffer, b_size(ptr_Buffer));

	/* display the contents of the input buffer */
	display(ptr_Buffer);

	/* pack the buffer
	* if possible, add end-of-file character (EOF) to the buffer
	* display again
	*/
	if (b_pack(ptr_Buffer)){
		if (!b_addc(ptr_Buffer, EOF))
			err_printf("%s%s%s", argv[0], ": ", "Error in writing to buffer.");
		display(ptr_Buffer);
	}


	/* destroy the buffer */
	b_destroy(ptr_Buffer);
	/* make the buffer invalid
	It is not necessary here because the function terminates anyway,
	but will prevent run-time errors and crashes in future expansions
	*/
	ptr_Buffer = NULL;
	/*return success */
	return (0);
}
Ejemplo n.º 4
0
/*
 * Purpose: Print the errors.
 * Author: Svillen Ranev
 * History/Versions: 1.0
 * Called functions: printf()
 */
void syn_printe() {
    Token t = lookahead;
    
    printf("PLATY: Syntax error:  Line:%3d\n",line);
    printf("*****  Token code:%3d Attribute: ", t.code);
    switch(t.code){
        case  ERR_T: /* ERR_T 0 Error token */
            printf("%s\n",t.attribute.err_lex);
            break;
        case  SEOF_T: /* SEOF_T 1 Source end-of-file token */
            printf("NA\n" );
            break;
        case  AVID_T: /* AVID_T 2 Arithmetic Variable identifier token */
        case  SVID_T :/* SVID_T 3 String Variable identifier token */
            printf("%s\n",sym_table.pstvr[t.attribute.get_int].plex);
            break;
        case  FPL_T: /* FPL_T 4 Floating point literal token */
            printf("%5.1f\n",t.attribute.flt_value);
            break;
        case INL_T: /* INL_T 5 Integer literal token */
            printf("%d\n",t.attribute.get_int);
            break;
        case STR_T:/* STR_T 6 String literal token */
            printf("%s\n",b_setmark(str_LTBL,t.attribute.str_offset));
            break;
            
        case SCC_OP_T: /* 7 String concatenation operator token */
            printf("NA\n" );
            break;
            
        case  ASS_OP_T:/* ASS_OP_T 8 Assignment operator token */
            printf("NA\n" );
            break;
        case  ART_OP_T:/* ART_OP_T 9 Arithmetic operator token */
            printf("%d\n",t.attribute.get_int);
            break;
        case  REL_OP_T: /* REL_OP_T 10 Relational operator token */
            printf("%d\n",t.attribute.get_int);
            break;
        case  LOG_OP_T:/* LOG_OP_T 11 Logical operator token */
            printf("%d\n",t.attribute.get_int);
            break;
            
        case  LPR_T: /* LPR_T 12 Left parenthesis token */
            printf("NA\n" );
            break;
        case  RPR_T: /* RPR_T 13 Right parenthesis token */
            printf("NA\n" );
            break;
        case LBR_T: /* 14 Left brace token */
            printf("NA\n" );
            break;
        case RBR_T: /* 15 Right brace token */
            printf("NA\n" );
            break;
            
        case KW_T: /* 16 Keyword token */
            printf("%s\n",kw_table [t.attribute.get_int]);
            break;
            
        case COM_T: /* 17 Comma token */
            printf("NA\n");
            break;
        case EOS_T: /* 18 End of statement *(semi - colon) */
            printf("NA\n" );
            break;
            
        default:
            printf("PLATY: Scanner error: invalid token code: %d\n", t.code);
    } /* end switch */
} /* end syn_printe() */
Ejemplo n.º 5
0
void print_token(Token t){
     extern char * kw_table []; /* link to keyword table in */
	 switch(t.code){
	case  ERR_T:
		printf("ERR_T\t\t%s",t.attribute.err_lex);
		if(scerrnum){
		 printf("%d",scerrnum);
		 exit(scerrnum);
		}printf("\n");
	break;
	case  SEOF_T:
		printf("SEOF_T\n" );
	break;
	case  AVID_T:
		printf("AVID_T\t\t%s\n",t.attribute.vid_lex);
	break;
	case  SVID_T:
		printf("SVID_T\t\t%s\n",t.attribute.vid_lex);
	break;
	case  FPL_T:
		printf("FPL_T\t\t%f\n",t.attribute.flt_value);
	break;
	case  INL_T:
	        printf("IL_T\t\t%d\n",t.attribute.get_int);
	break;
	case  STR_T:
	        printf("STR_T\t\t%d\t ",(short)t.attribute.get_int);
	        printf("%s\n", b_setmark(str_LTBL, (short)t.attribute.get_int));
	break;
	case  SCC_OP_T:
		printf("SCC_OP_T\n" );
	break;
	case  ASS_OP_T:
		printf("ASS_OP_T\n" );
	break;
	case  ART_OP_T:
		printf("ART_OP_T\t%d\n",t.attribute.get_int);
	break;
	case  REL_OP_T:
		printf("REL_OP_T\t%d\n",t.attribute.get_int);
	break;
	case  LOG_OP_T:
		printf("LOG_OP_T\t%d\n",t.attribute.get_int);
	break;
	case  LPR_T:
		printf("LPR_T\n" );
	break;
	case  RPR_T:
	        printf("RPR_T\n" );
	break;
	case LBR_T:
	        printf("LBR_T\n" );
	break;
	case RBR_T:
	        printf("RBR_T\n" );
	break;
	case KW_T:
	        printf("KW_T\t\t%s\n",kw_table [t.attribute.get_int]);
	break;
	case COM_T:
	        printf("COM_T\n");
	break;
	case EOS_T:
	        printf("EOS_T\n" );
	break;    
		
	default:
	        printf("Scanner error: invalid token code: %d\n", t.code);
 }
}
Ejemplo n.º 6
0
/*******************************************************************************
* Purpose:			Add a new entry into the symbol table array of STVR at the 
*					next available element. 
* Author:			Skye Turriff
* History:			Version 1, 19 November 2015
* Called functions:	st_lookup(), b_setmark(), b_size(), b_addc(), b_rflag(),
*					st_incoffset()
* Parameters:		STD sym_table struct with valid st_size
*					char* lexeme pointer to VID name to be added to table
*					char type of VID
*					int line of first occurence of VID
* Return value:		int offset into STVR array where VID record is installed, 
*					-2 on bad parameters, or -1 if symbol table is full.
* Algorithm:		Check parameters, return -2 if bad. If lexeme already in
*					symbol table, return the offset. If symbol table is full,
*					return -1. Set plex for new STVR to point to the next space
*					available in CA. Add each character in the VID lexeme to 
*					this location and make a C-type string. Once the new lexeme
*					has been added, if at any time the location of the CA was 
*					moved, re-calculate plex for each STVR in the STVR array. 
*					Finally, initialize remaining members for new STVR, and
*					increment st_offset of global sym_table. Return offset of
*					new STVR in STVR array.
*******************************************************************************/
int st_install(STD sym_table, char* lexeme, char type, int line) {
	int offset;		/* Offset into array of STVR */
	char r_flag;	/* Memory reallocation flag for lexeme storage buffer */
	char* tplex;	/* Used to iterate through lexeme storage buffer */
	int i;			/* Loop counter for iteration through STVR array */

	/* Check for valid symbol table */
	if (sym_table.st_size == 0) 
		return ERR_FAIL2;	

	/* Check if lexeme already exists */
	if ((offset = st_lookup(sym_table, lexeme)) != ERR_FAIL1) 
		return offset;

	/* Ensure there is room for a new record */
	if (sym_table.st_offset >= sym_table.st_size) 
		return ERR_FAIL1;

	/* Set plex for new VID record */
	sym_table.pstvr[sym_table.st_offset].plex =
		b_setmark(sym_table.plsBD, b_size(sym_table.plsBD));

	/* Install new entry into STVR array, make C-type string */
	r_flag = 0;
	for (; *lexeme; lexeme++) {
		b_addc(sym_table.plsBD, *lexeme);
		if (b_rflag(sym_table.plsBD)) 
			r_flag = 1;
	}
	b_addc(sym_table.plsBD, '\0');
	if (b_rflag(sym_table.plsBD)) 
		r_flag = 1;

	/* If r_flag set, use tplex to interate through lexeme storage 
	until '\0'. Then set plex of the current STVR to tplex + 1 */
	if (r_flag) {
		sym_table.pstvr[0].plex = b_setmark(sym_table.plsBD, 0);
		tplex = sym_table.pstvr[0].plex;
		for (i = 1; i <= sym_table.st_offset; i++) {
			while (*tplex) { tplex++;  continue; }
			sym_table.pstvr[i].plex = ++tplex;
		}
	}

	/* Record source line number */
	sym_table.pstvr[sym_table.st_offset].o_line = line;

	/* Initialize status_field and i_value */
	sym_table.pstvr[sym_table.st_offset].status_field &= DEFAULTZ;
	sym_table.pstvr[sym_table.st_offset].status_field |= DEFAULT;
	if (type == 'I') { /* integer */
		sym_table.pstvr[sym_table.st_offset].status_field |= DT_INT;
		sym_table.pstvr[sym_table.st_offset].i_value.int_val = 0;
	}
	else if (type == 'F') {	/* float */
		sym_table.pstvr[sym_table.st_offset].status_field |= DT_FPL;
		sym_table.pstvr[sym_table.st_offset].i_value.fpl_val = 0.0F;
	}
	else { /* string */
		sym_table.pstvr[sym_table.st_offset].status_field |= DT_STR;
		sym_table.pstvr[sym_table.st_offset].status_field |= SET_FLG;
		sym_table.pstvr[sym_table.st_offset].i_value.str_offset = -1;
	}

	st_incoffset();	/* Increment offset into STVR array of global sym_table */

	return sym_table.st_offset;
}
Ejemplo n.º 7
0
/********************************************************************
Function name:      st_install()
Purpose:            Install a new entry in the symbol table
Author:             Warren Rainey
History/Versions:   1.0
Called functions:   st_lookup(), b_setmark, b_get_r_flag(), b_addc(), b_get_chloc(), st_incoffset()
In parameters:      STD, char *, char, int
Return Value:       Int
Algorithm:			- Check if symbol table is valid
					- This function installs a new entry (VID record) in the symbol table.  
					First, It calls the st_lookup() function to search for the lexeme (variable name) in the symbol table. 
					- Add new record to symbol table and increment st_offest.
**********************************************************************/  
int st_install(STD sym_table, char *lexeme, char type, int line){
	int location = 0;
	int i = 0;
	int j = 0;
	STVR new_rec;
	
	/*intf("1lexeme: %s\n", lexeme);Test*/
	if(!sym_table.st_size){
		return R_FAIL_2;
	}

	location = st_lookup(sym_table,lexeme);

	if(location >= 0){/*lexeme found in symbol table*/  
		return location;
	}

	if(sym_table.st_offset == sym_table.st_size){
		return TABLE_FULL;
	}

	/*printf("2lexeme:%s\n", lexeme);Test*/
	/*sym_table.pstvr[sym_table.st_offset].plex = b_setmark(sym_table.plsBD,b_size(sym_table.plsBD));/*sym_table.st_offset*/
	new_rec.plex = b_setmark(sym_table.plsBD,b_size(sym_table.plsBD));/*sym_table.st_offset*/
	/*plex = b_setmark(sym_table.plsBD, getOffset(plsBD);
	b_setmark(sym_table.plsBD, 0); /*set to addc_offset*/
		for(i = 0; lexeme[i] != '\0'; i++){ /*add lexeme to lexeme storage*/
			b_addc(sym_table.plsBD, lexeme[i]);
			/*if plsBD has moves as result of realloc of buffer*/
			/*if( b_rflag(sym_table.plsBD)){/*Remove as it may creat p
				
				while(j < sym_table.st_offset){ 
					sym_table.pstvr[j].plex = temp;
					temp += strlen(temp) + 1; /* move temp to end of lexeme in buffer*
					j++;
				}
			}*/
		}
		b_addc(sym_table.plsBD, '\0');
		
	new_rec.status_field = DEFAULT;
	new_rec.o_line = line;
	
	
	/*Finding out if int, string or float*/
	if(type == 'I'){/*Is int*/
		new_rec.i_value.int_val = 0;
		new_rec.status_field |= SET_INTEGER;
	}else if(type == 'S'){/*Is string*/
		new_rec.i_value.str_offset = -1;
		new_rec.status_field |= SET_STRING;
		new_rec.status_field |= CHK_LSB;
	}else{/*Is float*/
		new_rec.i_value.fpl_val = 0.0f;
		new_rec.status_field |= SET_FLOAT;
	}
	/*printf("New plex: %s", new_rec.plex);Test*/
	sym_table.pstvr[sym_table.st_offset] = new_rec; /*add new record to table*/	
	st_incoffset();		
	return sym_table.st_offset;
}