shivananda199 / mini-c-compiler Goto Github PK

I came across your project and i want to try and explore it so that i can understand more about compiler building. on the file of"Semantic Analysis", i used flex parser.l which was successful, i used bison -d parser.y which was also successfull. But when i do gcc lex.yy.c i get this error:
parser.l:36:2: error: ‘yylval’ undeclared (first use in this function); did you mean ‘yylex’?
int {yylval.ival = INT; return INT;}
^~~~~~
yylex
parser.l:36:2: note: each undeclared identifier is reported only once for each function it appears in
parser.l:36:16: error: ‘INT’ undeclared (first use in this function); did you mean ‘EINTR’?
int {yylval.ival = INT; return INT;}
^~~
EINTR
parser.l:37:16: error: ‘FLOAT’ undeclared (first use in this function); did you mean ‘F_LOCK’?
float {yylval.ival = FLOAT; return FLOAT;}
^~~~~
F_LOCK
parser.l:38:16: error: ‘VOID’ undeclared (first use in this function)
void {yylval.ival = VOID; return VOID;}
^~~~
parser.l:39:9: error: ‘ELSE’ undeclared (first use in this function); did you mean ‘EILSEQ’?
else {return ELSE;}
^~~~
How can i solve it?

int scan, slcline=0, mlc=0, mlcline=0, dq=0, dqline=0;

We have ran our test4.c code on our output file.
It shows perfect output for your file.
But,
It shows syntax error for the same code when we run it from the file that we create (For e.g. test99.c).

Can you please throw some light on this issue and why such stuff is happening?