lab codes

LAB/03-02-17/lexicalerrors.l

@@ -0,0 +1,76 @@
+%{
+
+#include <stdio.h>
+
+enum {
+	NOTHING=0,
+	DATATYPE,
+	VARIABLE,
+	TERMINATOR
+};
+
+int seen = NOTHING;
+int check = 0;
+int line = 0;
+int offset = 0;
+
+%}
+
+datatype int|float|char
+variable [a-zA-Z_]*_[a-zA-Z0-9_]*
+terminator ;
+character .
+eol \n
+
+%%
+
+{datatype} {
+	offset += yyleng;
+	check = 1;
+	seen = DATATYPE;
+}
+
+{variable} {
+		if(seen == DATATYPE || seen == VARIABLE) {
+			offset += yyleng;
+			seen = VARIABLE;
+		} 
+		else {
+			seen = NOTHING;
+		}
+}
+
+{terminator} {
+		if(seen == VARIABLE) {
+			offset += yyleng;
+			seen = TERMINATOR;
+		} 
+		else {
+			seen = NOTHING;
+		}
+}
+
+{eol} {
+	++line;
+	if(check && seen != TERMINATOR) {
+		printf("Error at %d in line:[%d]\n", offset, line);
+		seen = NOTHING;
+		check = 0;
+	}
+	offset = 0;
+}
+
+{character} { 
+	++offset;
+} 
+
+%%
+
+int main(int argc, char *argv[])
+{
+        yyin = fopen(argv[1], "r");
+        yylex();
+        fclose(yyin);
+        return 0;
+}
+

LAB/03-02-17/syntax.l

@@ -0,0 +1,35 @@
+%option yylineno
+%option noyywrap
+
+type		int|float|char
+id		[a-zA-Z_][a-zA-Z_0-9]*
+ws		[ \t]+
+arr		"["[0-9]+"]"
+
+%s		WS
+%s		ID
+%s		ARR_COMMA_SEMI
+%s		ERROR
+
+%{
+int pos = 0;
+%}
+
+%%
+<INITIAL>{type}		{ BEGIN WS; pos+=yyleng; }
+<INITIAL>{ws}		{ pos+=yyleng; }
+<WS>{ws}		{ BEGIN ID; pos+=yyleng; }
+<ID>{id}		{ BEGIN ARR_COMMA_SEMI; pos+=yyleng; }
+<ARR_COMMA_SEMI>{arr}	{ pos+=yyleng; }
+<ARR_COMMA_SEMI>,	{ BEGIN ID; pos+=yyleng; }
+<ARR_COMMA_SEMI>;	{ BEGIN INITIAL; pos+=yyleng; }
+<ERROR>;		{ BEGIN INITIAL; pos+=yyleng; }
+<ERROR>.		{ pos+=yyleng; }
+\n			{ pos = 0; BEGIN INITIAL; }
+.			{ printf("Error:%d:%d\n", yylineno, pos+1); BEGIN ERROR; yyless(0); }
+%%
+
+int main(void)
+{
+	return yylex();
+}

LAB/03-02-17/syntaxerrors.l

@@ -0,0 +1,78 @@
+%{
+
+#include <stdio.h>
+
+enum {
+	NOTHING=0,
+	DATATYPE,
+	VARIABLE,
+	TERMINATOR
+};
+
+int seen = NOTHING;
+int check = 0;
+int line = 0;
+int offset = 0;
+int function = 0;
+
+%}
+
+datatype int|float|char
+variable [a-zA-Z_][a-zA-Z0-9_]*
+subscript (\[[0-9]*\])+
+terminator ;
+character .
+eol \n
+
+%%
+
+{datatype} {
+	offset += yyleng;
+	check = 1;
+	seen = DATATYPE;
+}
+
+{variable} {
+		if(seen == DATATYPE || seen == VARIABLE) {
+			offset += yyleng;
+			seen = VARIABLE;
+		} 
+		else {
+			seen = NOTHING;
+		}
+}
+
+{terminator} {
+		if(seen == VARIABLE) {
+			offset += yyleng;
+			seen = TERMINATOR;
+		} 
+		else {
+			seen = NOTHING;
+		}
+}
+
+{eol} {
+	++line;
+	if(check && seen != TERMINATOR) {
+		printf("Error at %d in line:[%d]\n", offset, line);
+		seen = NOTHING;
+		check = 0;
+	}
+	offset = 0;
+}
+
+{character} { 
+	++offset;
+} 
+
+%%
+
+int main(int argc, char *argv[])
+{
+        yyin = fopen(argv[1], "r");
+        yylex();
+        fclose(yyin);
+        return 0;
+}
+

LAB/03-03-17/expr/expr.l

@@ -0,0 +1,20 @@
+%{
+#include "expr.yacc.h"
+%}
+
+WS	[ \t]
+UOPT	"++"|"--"
+BOPT	"+"|"-"|"/"|"*"|"%"
+LOPT	"&"|"|"|"^"
+ID	[a-z]+
+NUM	[0-9]+
+
+%%
+{BOPT}{WS}*		{ puts("(BOPT)"); return BOPT; }
+{UOPT}{WS}*		{ puts("(UOPT)"); return UOPT; }
+{LOPT}{WS}*		{ puts("(LOPT)"); return LOPT; }
+{ID}{WS}*		{ puts("(ID)"); return ID; }
+{NUM}{WS}*		{ puts("(NUM)"); return NUM; }
+\n			{ return *yytext; }
+.			{ return *yytext; }
+%%

LAB/03-03-17/expr/expr.y

@@ -0,0 +1,40 @@
+%{
+#include <bits/stdc++.h>
+extern int yylex();
+extern int yyerror(const char*);
+%}
+
+%token UOPT BOPT LOPT ID NUM
+
+%%
+all:		expr all
+		|
+		;
+
+expr:		'\n'			{ puts("[nl]"); }
+		| unary			{ puts("[**[unary]**]"); }
+		| binary 		{ puts("[**[binary]**]"); }
+		| logical		{ puts("[**[logical]**]"); }
+		| opand			{ puts("[opand]"); }
+		;
+unary:		  UOPT opand		{ puts("[UOPT][opand]"); }
+		| opand UOPT		{ puts("[opand][UOPT]"); }
+		;
+binary:		  expr BOPT expr	{ puts("[expr][BOPT][expr]"); }
+		;
+logical:	  expr LOPT expr	{ puts("[expr][LOPT][expr]"); }
+		;
+opand:		  ID			{ puts("[ID]"); }
+		| NUM			{ puts("[NUM]"); }
+		;
+%%
+
+int yyerror(const char* s)
+{
+	fprintf(stderr, "%s\n", s);
+}
+
+int main(void)
+{
+	yyparse();
+}

LAB/03-03-17/expr/test.c

@@ -0,0 +1,7 @@
+#include <stdio.h>
+
+int main()
+{
+	int a, b;
+	int c = a+++++b;
+}

LAB/03-03-17/ifelse/g.c

@@ -0,0 +1 @@
+if(a+b){a+c}

LAB/03-03-17/ifelse/ifelse.l

@@ -0,0 +1,22 @@
+%{
+#include "ifelse.yacc.h"
+%}
+
+WS	[ \t\n]
+UOPT	"++"|"--"
+BOPT	"+"|"-"|"/"|"*"|"%"
+LOPT	"&"|"|"|"^"
+ID	[a-z]+
+NUM	[0-9]+
+
+%%
+if	return IF; 
+else	return ELSE;
+{BOPT}	return BOPT;
+{UOPT}	return UOPT; 
+{LOPT}	return LOPT;
+{ID}	return ID;
+{NUM}	return NUM;
+{WS}	;
+.	return *yytext;
+%%

LAB/03-03-17/ifelse/ifelse.y

@@ -0,0 +1,46 @@
+%{
+#include <bits/stdc++.h>
+extern int yylex();
+extern int yyerror(const char*);
+%}
+
+%token UOPT BOPT LOPT ID NUM IF ELSE
+
+%%
+
+stmt		: exprs			{ puts("[exprs]"); }
+		| '{' stmt '}'		{ puts("[stmt]"); }
+		| ifstmt		{ puts("[ifsmt]"); }
+		;
+ifstmt		: IF '(' expr ')' stmt	{ puts("[if]"); }
+		| ifstmt ELSE stmt	{ puts("[ifelse]"); }
+		;
+exprs		: exprs expr ';'	{ puts("[exprs expr ;]"); }
+		|
+		;
+expr		: unary			{ puts("[**[unary]**]"); }
+		| binary 		{ puts("[**[binary]**]"); }
+		| logical		{ puts("[**[logical]**]"); }
+		| opand			{ puts("[opand]"); }
+		;
+unary		: UOPT expr		{ puts("[UOPT][expr]"); }
+		| expr UOPT		{ puts("[expr][UOPT]"); }
+		;
+binary		: expr BOPT expr	{ puts("[expr][BOPT][expr]"); }
+		;
+logical		: expr LOPT expr	{ puts("[expr][LOPT][expr]"); }
+		;
+opand		: ID			{ puts("[ID]"); }
+		| NUM			{ puts("[NUM]"); }
+		;
+%%
+
+int yyerror(const char* s)
+{
+	fprintf(stderr, "%s\n", s);
+}
+
+int main(void)
+{
+	yyparse();
+}