S7 Compiler Lab Experiments (KTU 2019 Scheme)

Experiments

Sl. No.	Experiment
1	Lexical Analyzer using C
2	Lexical Analyzer using Lex
3	Lex program to display number of lines, words and characters
4	Lex program to convert abc -> ABC
5	Lex program to display number of vowels and consonants
6	Lex program to implement simple calculator
7	YACC Program to detect valid idenifier
8	YACC Program to detect valid arithmetic expression
9	Simple calculator using YACC
10	Program to find e-closure
11	Program to implement Shift Reduce Parser
12	Program to implement Recursive Descent Parser
13	Program to implement Intermediate Code generator
14	Program to implement Code generator
15	Program to perform Constant Propagation

gcc program.c 
./a.out

lex main.l
gcc lex.yy.c 
./a.out

lex prog.l
yacc -d prog.y -W
gcc lex.yy.c y.tab.c -w
./a.out

Installation: For running Lex and YACC Programs in your computer you have to install Flex and Bison respectively in your operating system.
- GNU/Linux
- Windows (Or Just use WSL or boot Gnu/Linux on your machine)
- MAC (IDK 🤷)
For YACC programs in newer versions of YACC and Bison compiler if gcc lex.yy.c y.tab.c -w returns an error like:

y.tab.c:1025:16: error: implicit declaration of function ‘yylex’ [-Wimplicit-function-declaration]
 1025 |       yychar = yylex ();

then simply edit .y file to include definition of that function in definition area (Within %{ %})

From:

%{
 #include<stdio.h>
 int valid=1;
%}

To:

%{
 #include<stdio.h>
 int yylex();
 int yyerror(); // if yyerror() also returns similar error
 int valid=1;
%}