Add a small set of logical operators to DDB command language.

This are based on Mach3.
Documentation is pending but has been promised.

Submitted by:	Dan Partelly
Reviewed by:	adrian, jhb (older version)

Differential Revision:	https://reviews.freebsd.org/D4230
RelNotes:	yes

sys/ddb/db_examine.c

@@ -225,6 +225,10 @@ db_print_cmd(db_expr_t addr, bool have_addr, db_expr_t count, char *modif)
 		else
 		    db_printf("\\%03o", (int)value);
 		break;
+	    default:
+		db_print_format = 'x';
+		db_error("Syntax error: unsupported print modifier\n");
+		/*NOTREACHED*/
 	}
 	db_printf("\n");
 }

sys/ddb/db_expr.c

@@ -43,6 +43,9 @@ static bool	db_mult_expr(db_expr_t *valuep);
 static bool	db_shift_expr(db_expr_t *valuep);
 static bool	db_term(db_expr_t *valuep);
 static bool	db_unary(db_expr_t *valuep);
+static bool	db_logical_or_expr(db_expr_t *valuep);
+static bool	db_logical_and_expr(db_expr_t *valuep);
+static bool	db_logical_relation_expr(db_expr_t *valuep);
 
 static bool
 db_term(db_expr_t *valuep)
@@ -108,19 +111,40 @@ db_unary(db_expr_t *valuep)
 	t = db_read_token();
 	if (t == tMINUS) {
 	    if (!db_unary(valuep)) {
-		db_error("Syntax error\n");
+		db_printf("Expression syntax error after '%c'\n", '-');
+		db_error(NULL);
 		/*NOTREACHED*/
 	    }
 	    *valuep = -*valuep;
 	    return (true);
 	}
+	if (t == tEXCL) {
+	    if(!db_unary(valuep)) {
+		db_printf("Expression syntax error after '%c'\n", '!');
+		db_error(NULL);
+		/* NOTREACHED  */
+	    }
+	    *valuep = (!(*valuep));
+	    return (true);
+	}
+	if (t == tBIT_NOT) {
+	    if(!db_unary(valuep)) {
+		db_printf("Expression syntax error after '%c'\n", '~');
+		db_error(NULL);
+		/* NOTREACHED */
+	    }
+	    *valuep = (~(*valuep));
+	    return (true);
+	}
 	if (t == tSTAR) {
 	    /* indirection */
 	    if (!db_unary(valuep)) {
-		db_error("Syntax error\n");
+		db_printf("Expression syntax error after '%c'\n", '*');
+		db_error(NULL);
 		/*NOTREACHED*/
 	    }
-	    *valuep = db_get_value((db_addr_t)*valuep, sizeof(void *), false);
+	    *valuep = db_get_value((db_addr_t)*valuep, sizeof(void *),
+		false);
 	    return (true);
 	}
 	db_unread_token(t);
@@ -137,24 +161,31 @@ db_mult_expr(db_expr_t *valuep)
 	    return (false);
 
 	t = db_read_token();
-	while (t == tSTAR || t == tSLASH || t == tPCT || t == tHASH) {
+	while (t == tSTAR || t == tSLASH || t == tPCT || t == tHASH ||
+	    t == tBIT_AND ) {
 	    if (!db_term(&rhs)) {
-		db_error("Syntax error\n");
+		db_printf("Expression syntax error after '%c'\n", '!');
+		db_error(NULL);
 		/*NOTREACHED*/
 	    }
-	    if (t == tSTAR)
+	    switch(t)  {
-		lhs *= rhs;
+		case tSTAR:
-	    else {
+		    lhs *= rhs;
-		if (rhs == 0) {
+		    break;
-		    db_error("Divide by 0\n");
+		case tBIT_AND:
-		    /*NOTREACHED*/
+		    lhs &= rhs;
-		}
+		    break;
-		if (t == tSLASH)
+		default:
-		    lhs /= rhs;
+		    if (rhs == 0) {
-		else if (t == tPCT)
+			db_error("Divide by 0\n");
-		    lhs %= rhs;
+			/*NOTREACHED*/
-		else
+		    }
-		    lhs = roundup(lhs, rhs);
+		    if (t == tSLASH)
+			lhs /= rhs;
+		    else if (t == tPCT)
+			lhs %= rhs;
+		    else
+			lhs = roundup(lhs, rhs);
 	    }
 	    t = db_read_token();
 	}
@@ -168,20 +199,32 @@ db_add_expr(db_expr_t *valuep)
 {
 	db_expr_t	lhs, rhs;
 	int		t;
+	char		c;
 
 	if (!db_mult_expr(&lhs))
 	    return (false);
 
 	t = db_read_token();
-	while (t == tPLUS || t == tMINUS) {
+	while (t == tPLUS || t == tMINUS || t == tBIT_OR) {
 	    if (!db_mult_expr(&rhs)) {
-		db_error("Syntax error\n");
+		c = db_tok_string[0];
+		db_printf("Expression syntax error after '%c'\n", c);
+		db_error(NULL);
 		/*NOTREACHED*/
 	    }
-	    if (t == tPLUS)
+	    switch (t) {
+	    case tPLUS:
 		lhs += rhs;
-	    else
+		break;
+	    case tMINUS:
 		lhs -= rhs;
+		break;
+	    case tBIT_OR:
+		lhs |= rhs;
+		break;
+	    default:
+		__unreachable();
+	    }
 	    t = db_read_token();
 	}
 	db_unread_token(t);
@@ -196,8 +239,7 @@ db_shift_expr(db_expr_t *valuep)
 	int		t;
 
 	if (!db_add_expr(&lhs))
-	    return (false);
+		return (false);
-
 	t = db_read_token();
 	while (t == tSHIFT_L || t == tSHIFT_R) {
 	    if (!db_add_expr(&rhs)) {
@@ -221,8 +263,109 @@ db_shift_expr(db_expr_t *valuep)
 	return (true);
 }
 
+static bool
+db_logical_relation_expr(
+	db_expr_t *valuep)
+{
+	db_expr_t	lhs, rhs;
+	int		t;
+	char		op[3];
+
+	if (!db_shift_expr(&lhs))
+	    return (false);
+
+	t = db_read_token();
+	while (t == tLOG_EQ || t == tLOG_NOT_EQ || t == tGREATER ||
+	    t == tGREATER_EQ || t == tLESS || t == tLESS_EQ) {
+	    op[0] = db_tok_string[0];
+	    op[1] = db_tok_string[1];
+	    op[2] = 0;
+	    if (!db_shift_expr(&rhs)) {
+		db_printf("Expression syntax error after \"%s\"\n", op);
+		db_error(NULL);
+		/*NOTREACHED*/
+	    }
+	    switch(t) {
+		case tLOG_EQ:
+		    lhs = (lhs == rhs);
+		    break;
+		case tLOG_NOT_EQ:
+		    lhs = (lhs != rhs);
+		    break;
+		case tGREATER:
+		    lhs = (lhs > rhs);
+		    break;
+		case tGREATER_EQ:
+		    lhs = (lhs >= rhs);
+		    break;
+		case tLESS:
+		    lhs = (lhs < rhs);
+		    break;
+		case tLESS_EQ:
+		    lhs = (lhs <= rhs);
+		    break;
+		default:
+		    __unreachable();
+	    }
+	    t = db_read_token();
+	}
+	db_unread_token(t);
+	*valuep = lhs;
+	return (true);
+}
+
+static bool
+db_logical_and_expr(
+	db_expr_t *valuep)
+{
+	db_expr_t	lhs, rhs;
+	int		t;
+
+	if (!db_logical_relation_expr(&lhs))
+	    return (false);
+
+	t = db_read_token();
+	while (t == tLOG_AND) {
+	    if (!db_logical_relation_expr(&rhs)) {
+		db_printf("Expression syntax error after '%s'\n", "&&");
+		db_error(NULL);
+		/*NOTREACHED*/
+	    }
+	    lhs = (lhs && rhs);
+	    t = db_read_token();
+	}
+	db_unread_token(t);
+	*valuep = lhs;
+	return (true);
+}
+
+static bool
+db_logical_or_expr(
+	db_expr_t *valuep)
+{
+	db_expr_t	lhs, rhs;
+	int		t;
+
+	if (!db_logical_and_expr(&lhs))
+		return(false);
+
+	t = db_read_token();
+	while (t == tLOG_OR) {
+		if (!db_logical_and_expr(&rhs)) {
+			db_printf("Expression syntax error after '%s'\n", "||");
+			db_error(NULL);
+			/*NOTREACHED*/
+		}
+		lhs = (lhs || rhs);
+		t = db_read_token();
+	}
+	db_unread_token(t);
+	*valuep = lhs;
+	return (true);
+}
+
 int
 db_expression(db_expr_t *valuep)
 {
-	return (db_shift_expr(valuep));
+	return (db_logical_or_expr(valuep));
 }

sys/ddb/db_lex.c

@@ -274,6 +274,10 @@ db_lex(void)
 	    case '/':
 		return (tSLASH);
 	    case '=':
+		c = db_read_char();
+		if (c == '=')
+		    return (tLOG_EQ);
+		db_unread_char(c);
 		return (tEQ);
 	    case '%':
 		return (tPCT);
@@ -290,21 +294,46 @@ db_lex(void)
 	    case '$':
 		return (tDOLLAR);
 	    case '!':
+		c = db_read_char();
+		if (c == '='){
+			return (tLOG_NOT_EQ);
+		}
+		db_unread_char(c);
 		return (tEXCL);
 	    case ';':
 		return (tSEMI);
+	    case '&':
+		c = db_read_char();
+		if (c == '&')
+		    return (tLOG_AND);
+		db_unread_char(c);
+		return (tBIT_AND);
+	    case '|':
+		c = db_read_char();
+		if (c == '|')
+		    return (tLOG_OR);
+		db_unread_char(c);
+		return (tBIT_OR);
 	    case '<':
 		c = db_read_char();
 		if (c == '<')
 		    return (tSHIFT_L);
+		if (c == '=') 
+		    return (tLESS_EQ);
 		db_unread_char(c);
-		break;
+		return (tLESS);
 	    case '>':
 		c = db_read_char();
 		if (c == '>')
 		    return (tSHIFT_R);
+		if (c == '=')
+		    return (tGREATER_EQ);
 		db_unread_char(c);
-		break;
+		return (tGREATER);
+	    case '?':
+		return (tQUESTION);
+	    case '~':
+		return (tBIT_NOT);
 	    case -1:
 		return (tEOF);
 	}

sys/ddb/db_lex.h

@@ -69,5 +69,18 @@ extern char	db_tok_string[TOK_STRING_SIZE];
 #define	tSHIFT_R	19
 #define	tDOTDOT		20
 #define	tSEMI		21
+#define	tLOG_EQ		22
+#define	tLOG_NOT_EQ	23
+#define	tLESS		24
+#define	tLESS_EQ	25
+#define	tGREATER	26
+#define	tGREATER_EQ	27
+#define	tBIT_AND	28
+#define	tBIT_OR		29
+#define	tLOG_AND	30
+#define	tLOG_OR		31
+#define	tSTRING		32
+#define	tQUESTION	33
+#define	tBIT_NOT	34
 
 #endif /* !_DDB_DB_LEX_H_ */