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Add logical negation

Logical negation are transformed into ternary operators.

--- a/cc.h

+++ b/cc.h

@@ -225,7 +225,7 @@

 	OBXOR, OBOR, OASSIGN, OA_MUL, OA_DIV,

 	OA_MOD, OA_ADD, OA_SUB, OA_SHL, OA_SHR,

 	OA_AND, OA_XOR, OA_OR, OADDR, OAND, OOR,

-	ONEG, OCPL,

+	ONEG, OCPL, OEXC

 };

 extern void

--- a/expr.c

+++ b/expr.c

@@ -5,8 +5,22 @@

 #define SWAP(x1, x2, t) (t = x1, x1 = x2, x2 = t)

+static Symbol *zero, *one;

+

 Node *expr(void);

+void

+init_expr(void)

+{

+	static Symbol zdummy, odummy;

+

+	zdummy.type = odummy.type = inttype;

+	zdummy.u.i = 0;

+	odummy.u.i = 1;

+	zero = &zdummy;

+	one = &odummy;

+}

+

 static Node *

 promote(Node *np)

 {

@@ -243,6 +257,20 @@

 }

 static Node *

+eval(Node *np, char neg)

+{

+	Node *ifyes, *ifno, *cmp;

+	char op;

+

+	ifyes = node(emitconst, inttype, SYM(one), 0);

+	ifno = node(emitconst, inttype, SYM(zero), 0);

+	cmp = node(emitconst, inttype, SYM(zero), 0);

+	op = (neg) ?  OEQ : ONE;

+

+	return ternarycode(compare(op, np, cmp), ifyes, ifno);

+}

+

+static Node *

 incdec(Node *np, char op)

 {

 	Type *tp;

@@ -365,11 +393,11 @@

 	case INC: case DEC:

 		op = (yytoken == INC) ? OINC : ODEC;

 		next();

-		return incdec(unary(), op);

-	/* TODO: case '!': */

+		return incdec(unary(), op); /* TODO: unary or cast? */

+	case '!': op = OEXC; break;

 	/* TODO: case '&': */

 	/* TODO: case '*': */

-	case '+': op = 0; break;

+	case '+': op = OADD; break;

 	case '~': op = OCPL; break;

 	case '-':  op = ONEG; break;

 	default: return postfix();

@@ -380,21 +408,32 @@

 	t = BTYPE(np->type);

 	switch (op) {

-	case OCPL:

+	case OEXC:

+		switch (t) {

+		case FTN: case ARY:

+			np = addr2ptr(np);

+		case INT: case FLOAT: case PTR:

+			np = eval(np, 1);

+			break;

+		default:

+			goto bad_operand;

+		}

+		break;

+	case OCPL: case OADD:

 		if (t != INT)

-			goto bad_complement;

+			goto bad_operand;

+		if (op == OADD)

+			break;

 	case ONEG:

 		if (!isarith(t))

-			goto bad_arithm;

+			goto bad_operand;

 		np = unarycode(op, np->type, np);

-	case 0:

-		return np;

 	}

-bad_complement:

-	error("bad operand in bit-complement");

-bad_arithm:

-	error("bad arithmetic operand in unary expression");

+	return np;

+

+bad_operand:

+	error("bad operand in unary expression");

 }

 static Node *

--- a/lex.c

+++ b/lex.c

@@ -28,7 +28,6 @@

 	static char ch;

 	/* TODO: implement again */

-

 type:

 	switch (ch = toupper(getc(yyin))) {

 	case 'L':

--- a/main.c

+++ b/main.c

@@ -4,7 +4,8 @@

 #include "cc.h"

-extern void extdecl(void), init_keywords(void), open_file(const char *file);

+extern void extdecl(void), init_keywords(void),

+	open_file(const char *file),  init_expr(void);

 struct user_opt options;

@@ -12,6 +13,7 @@

 main(int argc, char *argv[])

 {

 	init_keywords();

+	init_expr();

 	open_file(NULL);

 	for (next(); yytoken != EOFTOK; extdecl());

 		/* nothing */;