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lexer.c
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lexer.c
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/*
-- Group Number: 68
-- Name: Akhilesh Sudhakar ID: 2013A7PS173P
-- Name: Shubham Sharma ID: 2013A7PS110P
*/
#include <string.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
//#include "utils.h"
#include "lexerDef.h"
typedef char* buffer;
typedef unsigned long long buffersize;
typedef unsigned long long big;
// #define EOF 99
//TODO: init k =-1
big lineNumber = 1; // the "current line" in the source file
//char buffer[SIZE_MAX_BUFFER]; // the input buffer
int currentPointer; // indicates the current character to be read from the buffer
int bufferSize = -1; // the number of characters stored in the buffer (-1 indicates first use)
FILE* getStream(FILE *fp, buffer B, buffersize k){
memset(B, 0, k);
bufferSize = fread(B, sizeof(char),(size_t)k,fp);
currentPointer=0;
return fp;
}
void clean(tokenInfo *t){
memset(t->lexeme,0,SIZE_MAX_LEXEME);
memset(t->tokenType,0,SIZE_MAX_TOKEN);
memset(t->errorMsg,0,SIZE_MAX_ERROR_MSG);
t->isError=false;
}
char getNext(FILE *fp, buffer B, buffersize k) {
/* fetches the next character from the input stream
* uses buffering for efficiency
*/
char ch;
if(bufferSize == -1 || currentPointer == k){
getStream(fp, B, k);
}
if(bufferSize == 0 || (bufferSize == currentPointer +1 && bufferSize<k) )
return -1; // eof
else
ch=B[currentPointer];
currentPointer++;
return ch;
}
tokenInfo getNextTokenHelper(FILE *fp, buffer B, buffersize k,tokenInfo *t) {
clean(t);
char ch;
int dfaState=1;
big lexemeIndex=0;
int flag=0;
while(1){
ch=getNext(fp,B,k);
t->lexeme[lexemeIndex++] = ch; // store the character (to be used for identifiers etc.)
t->lineNumber = lineNumber; // update the line number in the token
switch(dfaState){
case 1:
switch(ch) {
//TODO: Make all tokens in double quotes
case '[': // TK_SQLfound
strcpy(t->tokenType,"TK_SQL");
return *t;
case ']': // TK_SQR found
strcpy(t->tokenType,"TK_SQR");
return *t;
case ';': // TK_SEM found
strcpy(t->tokenType,"TK_SEM");
return *t;
case ':': // TK_COLON found
strcpy(t->tokenType,"TK_COLON");
return *t;
case '.': // TK_DOT found
strcpy(t->tokenType,"TK_DOT");
return *t;
case '(': // TK_OP found
strcpy(t->tokenType,"TK_OP");
return *t;
case ')': // TK_CL found
strcpy(t->tokenType,"TK_CL");
return *t;
case '+': // TK_PLUS found
strcpy(t->tokenType,"TK_PLUS");
return *t;
case '-': // TK_MINUS found
strcpy(t->tokenType,"TK_MINUS");
return *t;
case '*': // TK_MUL found
strcpy(t->tokenType,"TK_MUL");
return *t;
case '/': // TK_DIV found
strcpy(t->tokenType,"TK_DIV");
return *t;
case '~': // TK_NOT found
strcpy(t->tokenType,"TK_NOT");
return *t;
case ',': // TK_COMMA found
strcpy(t->tokenType,"TK_COMMA");
return *t;
case '\n':
t->lexeme[lexemeIndex-1]='\0';
lexemeIndex--;
lineNumber++;
break;
case '%':
memset(t->lexeme,0,SIZE_MAX_LEXEME);
lexemeIndex=0;
char c;
c=getNext(fp,B,k);
while(c!='\n'){
c=getNext(fp,B,k);
}
lineNumber++;
break;
case '#':
dfaState = 2;
break;
case 'b':
case 'c':
case 'd':
dfaState =3;
break;
case '_':
dfaState=5;
break;
case '<':
dfaState=7;
break;
case '>':
dfaState=8;
break;
case '=':
dfaState=9;
break;
case '!':
dfaState=25;
break;
case '&':
dfaState=11;
break;
case '@':
dfaState=12;
break;
case ' ' :
case '\t':
t->lexeme[lexemeIndex-1]='\0';
lexemeIndex--;
break;
case EOF: // EOF
strcpy(t->tokenType,"TK_EOF");
return *t;
default :
if(ch >= 'a' && ch<='z'){
dfaState =4;
break;
}
else if(ch >= '0' && ch<='9'){
dfaState=6;
break;
}
else{
strcpy(t->tokenType,"TK_ERROR");
t->isError=true;
sprintf(t->errorMsg, "ERROR_2: Unknown Symbol <%c> at line %llu", ch,lineNumber);
return *t;
}
}
break;
case 2:
if(ch>='z'||ch<='a'){
if(ch == '\n' || ch == '\r' || ch == ' ' || ch == '\v' || ch == '\f' || ch == '\t' || ch == EOF){
sprintf(t->errorMsg, "ERROR_3: Unknown pattern # at <%llu>",lineNumber);
t->isError= true;
}
else
sprintf(t->errorMsg, "ERROR_3: Unknown pattern <%s> at <%llu>",t->lexeme,lineNumber);
strcpy(t->tokenType,"TK_ERROR");
return *t;
}
else{
ch=getNext(fp,B,k);
while(ch>='a'&&ch<='z'){
t->lexeme[lexemeIndex++]=ch;
ch=getNext(fp,B,k);
}
if(ch!=EOF){
currentPointer--;
}
strcpy(t->tokenType,"TK_RECORDID");
return *t;
}
break;
//TODO: CHECK THIS SHIT
case 3:
if(ch>='2'&& ch<='7'){
ch=getNext(fp,B,k);
if(ch>='b'&& ch<='d'){
t->lexeme[lexemeIndex++]=ch;
ch=getNext(fp,B,k);
while(ch>='b'&& ch<='d'){
t->lexeme[lexemeIndex++]=ch;
ch=getNext(fp,B,k);
}
if(ch>='2'&& ch<='7'){
t->lexeme[lexemeIndex++]=ch;
ch=getNext(fp,B,k);
while(ch>='2'&& ch<='7'){
t->lexeme[lexemeIndex++]=ch;
ch=getNext(fp,B,k);
}
if(ch!=EOF){
currentPointer--;
}
if(lexemeIndex>20){
strcpy(t->tokenType,"TK_ERROR");
t->isError=true;
sprintf(t->errorMsg, "ERROR_1 : Identifier at line <%llu>is longer than the prescribed length of 20 characters",lineNumber);
return *t;
}
else{
strcpy(t->tokenType,"TK_ID");
return *t;
}
}
else{
if(ch!=EOF){
currentPointer--;
}
if(lexemeIndex>20){
strcpy(t->tokenType,"TK_ERROR");
t->isError=true;
sprintf(t->errorMsg, "ERROR_1 : Identifier at line <%llu>is longer than the prescribed length of 20 characters",lineNumber);
return *t;
}
else{
strcpy(t->tokenType,"TK_ID");
return *t;
}
}
}
else if(ch>='2'&& ch<='7'){
t->lexeme[lexemeIndex++]=ch;
ch=getNext(fp,B,k);
while(ch>='2'&& ch<='7'){
t->lexeme[lexemeIndex++]=ch;
ch=getNext(fp,B,k);
}
if(ch!=EOF){
currentPointer--;
}
if(lexemeIndex>20){
strcpy(t->tokenType,"TK_ERROR");
t->isError=true;
sprintf(t->errorMsg, "ERROR_1 : Identifier at line <%llu>is longer than the prescribed length of 20 characters",lineNumber);
return *t;
}
else{
strcpy(t->tokenType,"TK_ID");
return *t;
}
}
else{
if(ch!=EOF){
currentPointer--;
}
if(lexemeIndex>20){
strcpy(t->tokenType,"TK_ERROR");
t->isError=true;
sprintf(t->errorMsg, "ERROR_1 : Identifier at line <%llu>is longer than the prescribed length of 20 characters",lineNumber); return *t;
}
else{
strcpy(t->tokenType,"TK_ID");
return *t;
}
}
}
else if(ch>='a'&& ch<='z'){
dfaState=4;
break;
}
else{
if(ch!=EOF){
currentPointer--;
}
t->lexeme[lexemeIndex-1]='\0';
strcpy(t->tokenType,"TK_FIELDID");
return *t;
}
break; //breaks case 3
case 4:
flag=0;
if(ch >= 'a' && ch<='z'){
flag =1;
ch=getNext(fp,B,k);
while(ch >= 'a' && ch<='z'){
t->lexeme[lexemeIndex++]=ch;
ch=getNext(fp,B,k);
}
}//TODO: double quotes
if(ch!=EOF){
currentPointer--;
}
if(!flag){
t->lexeme[lexemeIndex-1]='\0';
}
if(strcmp(t->lexeme, "with") == 0)
strcpy(t->tokenType,"TK_WITH");
else if(strcmp(t->lexeme, "parameters") == 0)
strcpy(t->tokenType,"TK_PARAMETERS");
else if(strcmp(t->lexeme, "end") == 0)
strcpy(t->tokenType,"TK_END");
else if(strcmp(t->lexeme, "while") == 0)
strcpy(t->tokenType,"TK_WHILE");
else if(strcmp(t->lexeme, "int") == 0)
strcpy(t->tokenType,"TK_INT");
else if(strcmp(t->lexeme, "real") == 0)
strcpy(t->tokenType,"TK_REAL");
else if(strcmp(t->lexeme, "type") == 0)
strcpy(t->tokenType,"TK_TYPE");
else if(strcmp(t->lexeme, "global") == 0)
strcpy(t->tokenType,"TK_GLOBAL");
else if(strcmp(t->lexeme, "parameter") == 0)
strcpy(t->tokenType,"TK_PARAMETER");
else if(strcmp(t->lexeme, "list") == 0)
strcpy(t->tokenType,"TK_LIST");
else if(strcmp(t->lexeme, "input") == 0)
strcpy(t->tokenType,"TK_INPUT");
else if(strcmp(t->lexeme, "output") == 0)
strcpy(t->tokenType,"TK_OUTPUT");
else if(strcmp(t->lexeme, "endwhile") == 0)
strcpy(t->tokenType,"TK_ENDWHILE");
else if(strcmp(t->lexeme, "if") == 0)
strcpy(t->tokenType,"TK_IF");
else if(strcmp(t->lexeme, "then") == 0)
strcpy(t->tokenType,"TK_THEN");
else if(strcmp(t->lexeme, "endif") == 0)
strcpy(t->tokenType,"TK_ENDIF");
else if(strcmp(t->lexeme, "read") == 0)
strcpy(t->tokenType,"TK_READ");
else if(strcmp(t->lexeme, "write") == 0)
strcpy(t->tokenType,"TK_WRITE");
else if(strcmp(t->lexeme, "return") == 0)
strcpy(t->tokenType,"TK_RETURN");
else if(strcmp(t->lexeme, "call") == 0)
strcpy(t->tokenType,"TK_CALL");
else if(strcmp(t->lexeme, "record") == 0)
strcpy(t->tokenType,"TK_RECORD");
else if(strcmp(t->lexeme, "endrecord") == 0)
strcpy(t->tokenType,"TK_ENDRECORD");
else if(strcmp(t->lexeme, "else") == 0)
strcpy(t->tokenType,"TK_ELSE");
else{
strcpy(t->tokenType,"TK_FIELDID");
}
return *t;
break;
case 5:
if((ch >= 'a' && ch<='z' ) || (ch >= 'A' && ch<='Z') ){
ch=getNext(fp,B,k);
while(ch >= 'a' && ch<='z' || ch >= 'A' && ch<='Z' ){
t->lexeme[lexemeIndex++]=ch;
ch=getNext(fp,B,k);
}
while(ch >= '0' && ch<='9'){
t->lexeme[lexemeIndex++]=ch;
ch=getNext(fp,B,k);
}
if(ch!=EOF){
currentPointer--;
}
if(lexemeIndex>30){
strcpy(t->tokenType,"TK_ERROR");
t->isError=true;
sprintf(t->errorMsg, "ERROR_1 : Identifier at line <%llu>is longer than the prescribed length of 30 characters",lineNumber);
return *t;
}
if(strcmp(t->lexeme, "_main") == 0){
strcpy(t->tokenType,"TK_MAIN");
return *t;
}
strcpy(t->tokenType,"TK_FUNID");
return *t;
}
else{
if(ch!=EOF){
currentPointer--;
}
strcpy(t->tokenType,"TK_ERROR");
t->isError=true;
sprintf(t->errorMsg, "ERROR_3: Unknown pattern <%s> at <%llu>",t->lexeme,lineNumber);
return *t;
}
break;
case 6:
flag=0;
while(ch>='0' && ch <='9'){
flag=1;
t->lexeme[lexemeIndex++]=ch;
ch=getNext(fp,B,k);
}
if(ch=='.'){
ch=getNext(fp,B,k);
if(ch>='0' && ch <='9'){
t->lexeme[lexemeIndex++]=ch;
ch=getNext(fp,B,k);
if(ch>='0' && ch <='9'){
t->lexeme[lexemeIndex++]=ch;
strcpy(t->tokenType,"TK_RNUM");
return *t;
}
else{
if(ch!=EOF){
currentPointer--;
}
strcpy(t->tokenType,"TK_ERROR");
t->isError=true;
t->lexeme[lexemeIndex++]=ch;
sprintf(t->errorMsg, "ERROR_3: Unknown pattern <%s> at <%llu>",t->lexeme,lineNumber);
return *t;
}
}
else{
if(ch!=EOF){
currentPointer--;
}
strcpy(t->tokenType,"TK_ERROR");
t->isError=true;
t->lexeme[lexemeIndex++]=ch;
sprintf(t->errorMsg, "ERROR_3: Unknown pattern <%s> at <%llu>",t->lexeme,lineNumber);
return *t;
}
}
else{
if(!flag){
t->lexeme[lexemeIndex-1]='\0';
}
if(ch!=EOF){
currentPointer--;
}
strcpy(t->tokenType,"TK_NUM");
return *t;
}
break;
case 7:
if(ch=='='){
strcpy(t->tokenType,"TK_LE");
return *t;
}
else if(ch=='-'){
ch=getNext(fp,B,k);
if(ch=='-'){
t->lexeme[lexemeIndex++]=ch;
ch=getNext(fp,B,k);
if(ch=='-'){
t->lexeme[lexemeIndex++]=ch;
strcpy(t->tokenType,"TK_ASSIGNOP");
return *t;
}
else{
if(ch!=EOF){
currentPointer--;
}
t->lexeme[lexemeIndex++]=ch;
strcpy(t->tokenType,"TK_ERROR");
t->isError=true;
sprintf(t->errorMsg, "ERROR_3: Unknown pattern <%s> at <%llu>",t->lexeme,lineNumber);
return *t;
}
}
else{
if(ch!=EOF){
currentPointer--;
}
t->lexeme[lexemeIndex++]=ch;
strcpy(t->tokenType,"TK_ERROR");
t->isError=true;
sprintf(t->errorMsg, "ERROR_3: Unknown pattern <%s> at <%llu>",t->lexeme,lineNumber);
return *t;
}
}
else{
if(ch!=EOF){
currentPointer--;
}
t->lexeme[lexemeIndex-1]='\0';
strcpy(t->tokenType,"TK_LT");
return *t;
}
break;
case 8:
if(ch=='='){
strcpy(t->tokenType,"TK_GE");
return *t;
}
else{
if(ch!=EOF){
currentPointer--;
}
t->lexeme[lexemeIndex-1]='\0';
strcpy(t->tokenType,"TK_GT");
return *t;
}
break;
case 9:
if(ch=='='){
strcpy(t->tokenType,"TK_EQ");
return *t;
}
else{
if(ch!=EOF){
currentPointer--;
}
t->lexeme[lexemeIndex++]=ch;
strcpy(t->tokenType,"TK_ERROR");
t->isError=true;
sprintf(t->errorMsg, "ERROR_3: Unknown pattern <%s> at <%llu>",t->lexeme,lineNumber);
} return *t;
break;
case 25:
if(ch=='='){
strcpy(t->tokenType,"TK_NE");
return *t;
}
else{
if(ch!=EOF){
currentPointer--;
}
t->lexeme[lexemeIndex++]=ch;
strcpy(t->tokenType,"TK_ERROR");
t->isError=true;
sprintf(t->errorMsg, "ERROR_3: Unknown pattern <%s> at <%llu>",t->lexeme,lineNumber);
} return *t;
break;
case 11:
if(ch=='&'){
ch=getNext(fp,B,k);
if(ch=='&'){
t->lexeme[lexemeIndex++]=ch;
strcpy(t->tokenType,"TK_AND");
return *t;
}
else{
if(ch!=EOF){
currentPointer--;
}
t->lexeme[lexemeIndex++]=ch;
strcpy(t->tokenType,"TK_ERROR");
t->isError=true;
sprintf(t->errorMsg, "ERROR_3: Unknown pattern <%s> at <%llu>",t->lexeme,lineNumber);
return *t;
}
}else{
if(ch!=EOF){
currentPointer--;
}
t->lexeme[lexemeIndex++]=ch;
strcpy(t->tokenType,"TK_ERROR");
t->isError=true;
sprintf(t->errorMsg, "ERROR_3: Unknown pattern <%s> at <%llu>",t->lexeme,lineNumber);
return *t;
}
break;
case 12:
if(ch=='@'){
ch=getNext(fp,B,k);
if(ch=='@'){
t->lexeme[lexemeIndex++]=ch;
strcpy(t->tokenType,"TK_OR");
return *t;
}
else{
if(ch!=EOF){
currentPointer--;
}
t->lexeme[lexemeIndex++]=ch;
strcpy(t->tokenType,"TK_ERROR");
t->isError=true;
sprintf(t->errorMsg, "ERROR_3: Unknown pattern <%s> at <%llu>",t->lexeme,lineNumber);
return *t;
}
}else{
if(ch!=EOF){
currentPointer--;
}
t->lexeme[lexemeIndex++]=ch;
strcpy(t->tokenType,"TK_ERROR");
t->isError=true;
sprintf(t->errorMsg, "ERROR_3: Unknown pattern <%s> at <%llu>",t->lexeme,lineNumber);
return *t;
}
break;
}
}
}
void commentRemover(FILE *fp){
buffer B;
buffersize k;
k=5;
B=(char *) malloc(k);
char ch;
ch = getNext(fp,B,k);
while(ch!=EOF){
if(ch=='%'){
ch = getNext(fp,B,k);
while(ch!='\n'){
ch = getNext(fp,B,k);
}
}else{
printf("%c",ch);
ch = getNext(fp,B,k);
}
}
bufferSize = -1;
lineNumber=1;
fseek(fp,0,SEEK_SET);
}
void printAllTokens(FILE *fp, buffer B, buffersize k){
tokenInfo t;
do{
clean(&t);
getNextTokenHelper(fp,B,k,&t);
if(t.isError == 1){
printf("\n%s %s",t.tokenType,t.errorMsg);
}else{
printf("\n%s %s %lu",t.tokenType,t.lexeme,t.lineNumber);
}
}while(strcmp(t.tokenType,"TK_EOF"));
bufferSize = -1;
lineNumber=1;
fseek(fp,0,SEEK_SET);
}
void updateFilePointer(FILE *fp){
bufferSize = -1;
lineNumber=1;
}
// void main(){
// commentRemover("a.txt");
// FILE* fp;
// fp=fopen("a.txt","r");
// buffer B;
// buffersize k;
// k=5;
// B=(char *) malloc(k);
// tokenInfo t;
// do{
// clean(&t);
// getNextTokenHelper(fp,B,k,&t);
// if(t.isError == 1){
// printf("\n%s %s",t.tokenType,t.errorMsg);
// }else{
// printf("\n%s %s %lu",t.tokenType,t.lexeme,t.lineNumber);
// }
// }while(strcmp(t.tokenType,"TK_EOF"));
// bufferSize = -1;
// lineNumber=1;
// fclose(fp);
// commentRemover("a.txt");
// }