shithub: scc

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Add sizeof operator

This operator returns the size of a type or an expression.

--- a/cc.h

+++ b/cc.h

@@ -112,6 +112,8 @@

 extern void context(void (*fun)(void));

+extern Type *typename(void);

+

 extern Type *voidtype,

 	*uchartype,   *chartype,

 	*uinttype,    *inttype,

--- a/expr.c

+++ b/expr.c

@@ -300,6 +300,7 @@

 		next();

 		np = expr();

 		expect(')');

+	case ';':

 		break;

 	default:

 		error("unexpected '%s'", yytext);

@@ -335,8 +336,27 @@

 unary(void)

 {

 	register Node *np;

+	Type *tp;

+	char paren;

 	switch (yytoken) {

+	case SIZEOF:

+		next();

+		if (accept('('))

+			paren = 1;

+		switch (yytoken) {

+		case TQUALIFIER: case TYPE:

+			tp = typename();

+			break;

+		default:

+			tp = expr()->type;

+			/* TODO: Free memory */

+			break;

+		}

+		if (paren)

+			expect(')');

+		np = sizeofcode(tp);

+		break;

 	case INC: case DEC:

 		np = incdec(unary(), (yytoken == INC) ? OINC : ODEC);

 		next();

@@ -351,7 +371,6 @@

 {

 	Type *tp;

 	register Node *np1, *np2;

-	extern Type *typename(void);

 	if (yytoken == '(') {

 		switch(ahead()) {