int detectError( char *s ){
int i;
int len = (int) strlen( s );
//Check for single colon token.
if( len == 1 && s[0] == ':' ){
printf( "Error: Invalid Symbol: :\n" );
return 1;
}
//Check for invalid symbol.
for( i = 0; i < len; i++ ){
if( !isalnum(s[i]) && !isSpecialSymbol( s[i] ) ){
printf( "Error: Invalid Symbol: %c\n", s[i] );
return 1;
}
}
//Single letter & single number accepted, so if s > 1.
if( len > 1 ){
//Check identifier length.
if( isalpha( s[0] ) ){
for( i = 1; i < len; i++ ){
if( i > MAX_ID_LEN ){
printf( "Error: Variable name: %s is too long.\n", s );
return 1;
}
}
}
if( isdigit( s[0] ) ){
//Check invalid identifier (starts with number).
for( i = 1; i < len; i++ ){
if( isalpha( s[i] ) ){
printf( "Error: Variable name: %s begins with a number.\n", s );
return 1;
}
}
//Check number length.
if( i > MAX_NUM_LEN ){
printf( "Error: Number %s is too long.\n", s );
return 1;
}
}
}
return 0;
} //End of detectError.
enum status typeCheck(char* lookAhead)
{
if (isLetter(*lookAhead))
return ID;
if (isDigit(*lookAhead))
return DIGIT;
if (isWhiteSpace(*lookAhead))
return WHITE_SPACE;
if (isSpecialSymbol(*lookAhead))
return SPECIAL_SYMBOL;
if (*lookAhead == -1)
return ENDFILE;
return ERROR;
}
int main( void ){
int i; //Loop counter.
int tempTokCtr = 0; //Count number of tokens.
char buffer[ 10000 ]; //For reading in tokens.
char temp[ 10000 ]; //Back-up buffer.
//Prompt user for source program name.
char sp[50]; //Name of input file.
printf( "What is the file name for your source program?\n" );
scanf( "%s", sp );
//Open file input stream to main input (the program).
FILE *fin = fopen( sp, "r" );
//Open file output stream to intermediary output file.
//In this file, unprocessed tokens will be stored for further processing.
FILE *temp_fout = fopen( "temp_output.txt", "w" );
//Procedure for creating intermediary output.
/** BEGIN PROCEDURE **/
while( fscanf( fin, "%s", buffer ) != EOF ){
int len = (int) strlen( buffer ); //Length of read-in token.
//For the length of the read-in token:
for( i = 0; i < len; i++ ){
//If we've reached the end of the buffer, and it's not a special symbol, print the token.
//If invalid symbols are present, they're ignored and taken care of later.
if( i == len-1 && !isSpecialSymbol( buffer[ i ] ) ){
fprintf( temp_fout, "%s ", buffer );
tempTokCtr++; //Increment the token counter.
}
//If the i-th element of the token is a special symbol.
else if( isSpecialSymbol( buffer[ i ] ) ){
//Brute force examine particular token cases: comment tokems, not equal, less-than-or-equal, ... , null, and odd.
if( len > 1 ){
if( buffer[ i ] == '/' && buffer[ i+1 ] == '*' ){
strncpy( temp, buffer, i );
temp[ i ] = '\0';
fprintf( temp_fout, "%s ", temp );
tempTokCtr++;
fprintf( temp_fout, "/* " );
tempTokCtr++;
strncpy( buffer, &buffer[i]+2, len-1 );
buffer[ len - 1 ] = '\0';
len = (int) strlen( buffer );
i = -1;
}
else if( buffer[ i ] == '*' && buffer[ i+1 ] == '/' ){
strncpy( temp, buffer, i );
temp[ i ] = '\0';
fprintf( temp_fout, "%s ", temp );
tempTokCtr++;
fprintf( temp_fout, "*/ " );
tempTokCtr++;
strncpy( buffer, &buffer[i]+2, len-1 );
buffer[ len - 1 ] = '\0';
len = (int) strlen( buffer );
i = -1;
}
else if( buffer[ i ] == '!' && buffer[ i+1 ] == '=' ){
strncpy( temp, buffer, i );
temp[ i ] = '\0';
fprintf( temp_fout, "%s ", temp );
tempTokCtr++;
fprintf( temp_fout, "!= " );
tempTokCtr++;
strncpy( buffer, &buffer[i]+2, len-1 );
buffer[ len - 1 ] = '\0';
len = (int) strlen( buffer );
i = -1;
}
else if( buffer[ i ] == '<' && buffer[ i+1 ] == '=' ){
strncpy( temp, buffer, i );
temp[ i ] = '\0';
fprintf( temp_fout, "%s ", temp );
tempTokCtr++;
fprintf( temp_fout, "<= " );
tempTokCtr++;
strncpy( buffer, &buffer[i]+2, len-1 );
buffer[ len - 1 ] = '\0';
len = (int) strlen( buffer );
i = -1;
}
else if( buffer[ i ] == '>' && buffer[ i+1 ] == '=' ){
strncpy( temp, buffer, i );
temp[ i ] = '\0';
fprintf( temp_fout, "%s ", temp );
tempTokCtr++;
fprintf( temp_fout, ">= " );
tempTokCtr++;
strncpy( buffer, &buffer[i]+2, len-1 );
buffer[ len - 1 ] = '\0';
len = (int) strlen( buffer );
i = -1;
}
else if( buffer[ i ] == ':' && buffer[ i+1 ] == '=' ){
strncpy( temp, buffer, i );
temp[ i ] = '\0';
fprintf( temp_fout, "%s ", temp );
tempTokCtr++;
fprintf( temp_fout, ":= " );
tempTokCtr++;
strncpy( buffer, &buffer[i]+2, len-1 );
buffer[ len - 1 ] = '\0';
len = (int) strlen( buffer );
i = -1;
}
else if( len > 3 && buffer[ i ] == 'n' && buffer[ i+1 ] == 'u' && buffer[ i+2 ] == 'l' && buffer[ i+3 ] =='l' ){
strncpy( temp, buffer, i );
temp[ i ] = '\0';
fprintf( temp_fout, "%s ", temp );
tempTokCtr++;
fprintf( temp_fout, "null " );
tempTokCtr++;
strncpy( buffer, &buffer[i]+4, len-1 );
buffer[ len - 1 ] = '\0';
len = (int) strlen( buffer );
i = -1;
}
else if( len > 2 && buffer[ i ] == 'o' && buffer[ i+1 ] == 'd' && buffer[ i+2 ] == 'd' ){
strncpy( temp, buffer, i );
temp[ i ] = '\0';
fprintf( temp_fout, "%s ", temp );
tempTokCtr++;
fprintf( temp_fout, "odd " );
tempTokCtr++;
strncpy( buffer, &buffer[i]+3, len-1 );
buffer[ len - 1 ] = '\0';
len = (int) strlen( buffer );
i = -1;
}
}
//Special symbol token at the beginning.
if( i == 0 ){
//Print symbol as individual token.
fprintf( temp_fout, "%c ", buffer[i] );
tempTokCtr++; //Increment token counter.
//Shift buffer, and update loop index.
//Similar procedure used for brute force token examination, and further token examination.
strncpy( buffer, &buffer[i]+1, len-1 );
buffer[ len - 1 ] = '\0';
len = (int) strlen( buffer );
i = -1;
}
//Valid symbol is splitting tokens within the buffer; split, print, and shift the tokens left of the valid symbol, including the symbol.
if( i > 0 ){
strncpy( temp, buffer, i );
temp[ i ] = '\0';
fprintf( temp_fout, "%s ", temp );
tempTokCtr++;
fprintf( temp_fout, "%c ", buffer[i] );
tempTokCtr++;
strncpy( buffer, &buffer[i]+1, len-1 );
buffer[ len - 1 ] = '\0';
len = (int) strlen( buffer );
i = -1;
}
}
}
}
/** END OF PROCEDURE **/
//Resource management.
fclose( temp_fout );
fclose( fin );
//Open file input stream to intermediary output created by the procedure above (unprocessed tokens).
fin = fopen( "temp_output.txt", "r" );
FILE *table = fopen( "lexeme_table.txt", "w" ); //Will hold the lexeme table.
FILE *list = fopen( "lexeme_list.txt", "w" ); //Will hold the lexeme list.
//Print header for lexeme table.
fprintf( table, "Lexeme Table:\n%15s%15s\n", "lexeme", "token type");
//Procedure to examine printed tokens.
/** BEGIN PROCEDURE **/
//Initialize.
int isResWord = -1; //If currently examined token is a reserved word, != -1; otherwise, = -1.
int len = 0; //Length of examined token.
int isComment = 0; //If currently reading in a comment, = 1; otherwise, = 0.
//For the length of tokens.
while( fscanf( fin, "%s ", buffer ) != EOF ){
//fscanf( fin, "%s", buffer ); //Read in token.
len = (int) strlen( buffer ); //Get token string length.
//Recognize beginning of comment block.
if( !strcmp( buffer, "/*" ) ){
isComment = 1;
}
//Recognize end of comment block.
else if( isComment == 1 && !strcmp( buffer, "*/" ) ){
isComment = 0;
}
//Only read in tokens while not examining a comment block.
else if( !isComment ){
//Error detection by token.
if( detectError( buffer ) ){
fclose( fin );
fclose( table );
fclose( list );
exit( 0 );
}
//Is the current token a reserved word? Print to table and list appropriately.
isResWord = isReservedWord( buffer );
if( isResWord != -1 ){
fprintf( table, "%15s%15d\n", buffer, isResWord );
fprintf( list, "%d ", isResWord );
}
//Is the current token an identifier? Print to table and list appropriately.
else if( isalpha( buffer[0] ) ){
fprintf( table, "%15s%15d\n", buffer, 2 );
fprintf( list, "2 %s ", buffer );
}
//Is the current token a number? Print to table and list appropriately.
else if( isdigit( buffer[0] ) ){
fprintf( table, "%15s%15d\n", buffer, 3 );
fprintf( list, "3 %s ", buffer );
}
//Otherwise, our token is some other valid symbol (checked for errors above). Print appropriately.
else{
fprintf( table, "%15s%15d\n", buffer, isOtherValid( buffer ) );
fprintf( list, "%d ", isOtherValid( buffer ) );
}
}
}
//Resource management.
fclose( fin );
fclose( table );
fclose( list );
/** END OF PROCEDURE **/
//Procedure to copy and source program.
/** BEGIN PROCEDURE **/
fin = fopen( sp, "r" ); //File containing source program.
FILE *source = fopen( "source_program.txt", "w" ); //File to copy source program to.
char copy; //Used to copy file, character by character.
//Copy character by character, until end of file.
while( ( copy = fgetc( fin ) ) != EOF )
fputc( copy, source );
//Resource management.
fclose( fin );
fclose( source );
remove( "temp_output.txt" ); //Delete intermediary output.
/** END OF PROCEDURE **/
return 0;
} //End of main.
int scanner(char* fileName)
{
tokenPointer tokenList = NULL;
FILE* sourceCode = fopen(fileName, "r");
char lookAhead; /* 탐색을 위한 Character */
if (sourceCode == NULL) /* 파일 입출력 실패 */
{
printf("File open fail\n");
return FALSE;
}
else /* 파일 입출력 성공 */
{
printf("=====File open successfully=====\n");
/* File read */
while ((lookAhead = fgetc(sourceCode)) != EOF) /* lookAhead로 문자열을 하나씩 컨슘함 */
{
/* 타입 체크 */
if (type != COMMENT)
type = typeCheck(&lookAhead);
do
{
noConsume = FALSE; /* 서로 다른 타입의 심볼이 붙어 있는지 판별 */
switch (type)
{
case WHITE_SPACE:
break;
case COMMENT: /* 코멘트일 경우 끝날 때까지 모두 컨슘 */
checkInComment(sourceCode, &lookAhead, &line, &type);
break;
case ID:
if (checkInID(sourceCode, &lookAhead, identifier))
makeToken(&tokenList, identifier, type, line, &count);
if (!isLetter(lookAhead) && !isWhiteSpace(lookAhead))
{
noConsume = TRUE;
type = typeCheck(&lookAhead);
}
break;
case DIGIT:
if (checkInDigit(sourceCode, &lookAhead, identifier))
makeToken(&tokenList, identifier, type, line, &count);
if (!isDigit(lookAhead) && !isWhiteSpace(lookAhead))
{
noConsume = TRUE;
type = typeCheck(&lookAhead);
}
break;
case SPECIAL_SYMBOL:
switch (checkInSpecialSymbol(sourceCode, &lookAhead, identifier))
{
case TRUE: /* 일반적인 특수문자 일 경우 */
makeToken(&tokenList, identifier, type, line, &count);
break;
case COMMENT: /* 코멘트일 경우 */
type = COMMENT;
break;
case ERROR: /* 에러가 났을 경우 */
type = ERROR;
break;
}
if (!isSpecialSymbol(lookAhead) && !isWhiteSpace(lookAhead))
{
noConsume = TRUE;
type = typeCheck(&lookAhead);
}
break;
case ERROR:
checkInError(sourceCode, &lookAhead, identifier);
makeToken(&tokenList, identifier, ERROR, line, &count);
type = typeCheck(&lookAhead);
if (type != ERROR) /* 에러를 처리한 후 타입이 에러가 아니라도 미리 앞을 봤으므로 컨슘을 또 하지 않음 */
noConsume = TRUE;
break;
}
if (lookAhead == '\n')
line++;
} while (noConsume || type == ERROR); /* 서로 다른 타입의 심볼이 붙어 있을 경우, 에러일 경우 fgetc로 컨슘 하지 않고 바로 다시 체크 */
}
printOut(tokenList, sourceCode);
if (fclose(sourceCode) == 0)
printf("=====File close successfully=====\n");
else
printf("=====File close fail=====\n");
}
}