From 0368474a6a610d15c7de92010fde161d9e465180 Mon Sep 17 00:00:00 2001
From: kevans <kevans@FreeBSD.org>
Date: Sun, 6 Jan 2019 02:17:18 +0000
Subject: [PATCH] MFC r342362-r342363: config(8) duplicate option handling

r342362:
config(8): Allow duplicate options to be specified

config(8)'s option handling has been written to allow duplicate options; if
the value changes, then the latest value is used and an informative message
is printed to stderr like so:

/usr/src/sys/amd64/conf/TEST: option "VERBOSE_SYSINIT" redefined from 0 to 1

Currently, this is only a possibility for cpu types, MAXUSERS, and
MACHINE_ARCH. Anything else duplicated in a config file will use the first
value set and error about duplicated options on subsequent appearances,
which is arguably unfriendly since one could specify:

include GENERIC
nooptions VERBOSE_SYSINIT
options VERBOSE_SYSINIT

to redefine the value later anyways.

Reported by:	mmacy

r342363:
config(8): Remove all instances of an option when opting out

Quick follow-up to r342362: options can appear multiple times now, so
clean up all of them as needed. For non-OPTIONS options, this has no effect
since they're already de-duplicated.
---
 usr.sbin/config/config.y | 37 +++++++++++++++++++++----------------
 1 file changed, 21 insertions(+), 16 deletions(-)

diff --git a/usr.sbin/config/config.y b/usr.sbin/config/config.y
index e5296a27156..26bf4c160c9 100644
--- a/usr.sbin/config/config.y
+++ b/usr.sbin/config/config.y
@@ -97,7 +97,7 @@ static void newdev(char *name);
 static void newfile(char *name);
 static void newenvvar(char *name, bool is_file);
 static void rmdev_schedule(struct device_head *dh, char *name);
-static void newopt(struct opt_head *list, char *name, char *value, int append);
+static void newopt(struct opt_head *list, char *name, char *value, int append, int dupe);
 static void rmopt_schedule(struct opt_head *list, char *name);
 
 static char *
@@ -210,7 +210,7 @@ System_spec:
 	  ;
 
 System_id:
-	Save_id { newopt(&mkopt, ns("KERNEL"), $1, 0); };
+	Save_id { newopt(&mkopt, ns("KERNEL"), $1, 0, 0); };
 
 System_parameter_list:
 	  System_parameter_list ID
@@ -230,13 +230,13 @@ NoOpt_list:
 		;
 Option:
 	Save_id {
-		newopt(&opt, $1, NULL, 0);
+		newopt(&opt, $1, NULL, 0, 1);
 		if (strchr($1, '=') != NULL)
 			errx(1, "%s:%d: The `=' in options should not be "
 			    "quoted", yyfile, yyline);
 	      } |
 	Save_id EQUALS Opt_value {
-		newopt(&opt, $1, $3, 0);
+		newopt(&opt, $1, $3, 0, 1);
 	      } ;
 
 NoOption:
@@ -264,10 +264,10 @@ Mkopt_list:
 		;
 
 Mkoption:
-	Save_id { newopt(&mkopt, $1, ns(""), 0); } |
-	Save_id EQUALS { newopt(&mkopt, $1, ns(""), 0); } |
-	Save_id EQUALS Opt_value { newopt(&mkopt, $1, $3, 0); } |
-	Save_id PLUSEQUALS Opt_value { newopt(&mkopt, $1, $3, 1); } ;
+	Save_id { newopt(&mkopt, $1, ns(""), 0, 0); } |
+	Save_id EQUALS { newopt(&mkopt, $1, ns(""), 0, 0); } |
+	Save_id EQUALS Opt_value { newopt(&mkopt, $1, $3, 0, 0); } |
+	Save_id PLUSEQUALS Opt_value { newopt(&mkopt, $1, $3, 1, 0); } ;
 
 Dev:
 	ID { $$ = $1; }
@@ -293,7 +293,7 @@ NoDev_list:
 
 Device:
 	Dev {
-		newopt(&opt, devopt($1), ns("1"), 0);
+		newopt(&opt, devopt($1), ns("1"), 0, 0);
 		/* and the device part */
 		newdev($1);
 		}
@@ -430,7 +430,7 @@ findopt(struct opt_head *list, char *name)
  * Add an option to the list of options.
  */
 static void
-newopt(struct opt_head *list, char *name, char *value, int append)
+newopt(struct opt_head *list, char *name, char *value, int append, int dupe)
 {
 	struct opt *op, *op2;
 
@@ -443,7 +443,7 @@ newopt(struct opt_head *list, char *name, char *value, int append)
 	}
 
 	op2 = findopt(list, name);
-	if (op2 != NULL && !append) {
+	if (op2 != NULL && !append && !dupe) {
 		fprintf(stderr,
 		    "WARNING: duplicate option `%s' encountered.\n", name);
 		return;
@@ -456,9 +456,15 @@ newopt(struct opt_head *list, char *name, char *value, int append)
 	op->op_ownfile = 0;
 	op->op_value = value;
 	if (op2 != NULL) {
-		while (SLIST_NEXT(op2, op_append) != NULL)
-			op2 = SLIST_NEXT(op2, op_append);
-		SLIST_NEXT(op2, op_append) = op;
+		if (append) {
+			while (SLIST_NEXT(op2, op_append) != NULL)
+				op2 = SLIST_NEXT(op2, op_append);
+			SLIST_NEXT(op2, op_append) = op;
+		} else {
+			while (SLIST_NEXT(op2, op_next) != NULL)
+				op2 = SLIST_NEXT(op2, op_next);
+			SLIST_NEXT(op2, op_next) = op;
+		}
 	} else
 		SLIST_INSERT_HEAD(list, op, op_next);
 }
@@ -471,8 +477,7 @@ rmopt_schedule(struct opt_head *list, char *name)
 {
 	struct opt *op;
 
-	op = findopt(list, name);
-	if (op != NULL) {
+	while ((op = findopt(list, name)) != NULL) {
 		SLIST_REMOVE(list, op, opt, op_next);
 		free(op->op_name);
 		free(op);
-- 
2.45.2