[#2084] Addressed all concerns outside .yy files

28 files changed, 92 insertions, 83 deletions

diff --git a/ChangeLog b/ChangeLog
index f7ac3d9da0..b40d9c9467 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,8 +1,8 @@
 1972.	[func]		andrei
-	Kea servers now accept trailing commas in file configurations.
-	While parsing, a warning is printed with the location of the
-	comma to give the user the ability to correct a potential
-	mistake.
+	Kea servers now can accept trailing commas in file
+	configurations. While parsing, a warning is printed with the
+	location of the comma to give the user the ability to correct
+	a mistake.
 	(Gitlab #2084)
 
 1971.	[func]		tmark, jad
diff --git a/doc/devel/doc.dox b/doc/devel/doc.dox
index 1ae1bf33a7..cde7f9071c 100644
--- a/doc/devel/doc.dox
+++ b/doc/devel/doc.dox
@@ -65,12 +65,11 @@ means that some trickery with escaping double quotes will be involved. Note
 there is no need to escape any other character, unless you want to specify
 non-printable characters.
 
-Also, while Kea's JSON parser supports comments, multi-line strings and extra
-commas, they are not part of JSON standard. That means that external tools, such
-as python or Sphinx parsers are not able to deal with them. Therefore comments
-and extra commas must be removed. Long strings (such as command descriptions or
-example invocations) are to be presented as a list of strings
-e.g. [ "line1", "line2, "line3" ].
+Also, while Kea's JSON parser supports comments and multi-line string, they
+are not part of JSON standard. That means that external tools, such as python
+or Sphinx parsers are not able to deal with them. Therefore comments must
+be removed and long strings (such as command descriptions or example invocations)
+are to be presented as a list of strings ( e.g. [ "line1", "line2, "line3" ]).
 
 @section docsDevelGuide Generating Developer's Guide
 
diff --git a/doc/sphinx/arm/config.rst b/doc/sphinx/arm/config.rst
index 1bb1e31ef8..684e4815d3 100644
--- a/doc/sphinx/arm/config.rst
+++ b/doc/sphinx/arm/config.rst
@@ -60,8 +60,8 @@ Kea components use extended JSON with additional features allowed:
 
 .. warning::
 
-   These features are meant to be used in a JSON configuration. Their usage in
-   any other way may result in errors.
+   These features are meant to be used in a JSON configuration file.
+   Their usage in any other way may result in errors.
 
 The configuration file consists of a single object (often colloquially
 called a map) started with a curly bracket. It comprises only one of
diff --git a/src/bin/agent/ca_messages.cc b/src/bin/agent/ca_messages.cc
index 30c4038bda..3a7ee2e79a 100644
--- a/src/bin/agent/ca_messages.cc
+++ b/src/bin/agent/ca_messages.cc
@@ -12,6 +12,7 @@ extern const isc::log::MessageID CTRL_AGENT_COMMAND_FORWARD_BEGIN = "CTRL_AGENT_
 extern const isc::log::MessageID CTRL_AGENT_COMMAND_FORWARD_FAILED = "CTRL_AGENT_COMMAND_FORWARD_FAILED";
 extern const isc::log::MessageID CTRL_AGENT_CONFIG_CHECK_FAIL = "CTRL_AGENT_CONFIG_CHECK_FAIL";
 extern const isc::log::MessageID CTRL_AGENT_CONFIG_FAIL = "CTRL_AGENT_CONFIG_FAIL";
+extern const isc::log::MessageID CTRL_AGENT_CONFIG_SYNTAX_WARNING = "CTRL_AGENT_CONFIG_SYNTAX_WARNING";
 extern const isc::log::MessageID CTRL_AGENT_FAILED = "CTRL_AGENT_FAILED";
 extern const isc::log::MessageID CTRL_AGENT_HTTPS_SERVICE_STARTED = "CTRL_AGENT_HTTPS_SERVICE_STARTED";
 extern const isc::log::MessageID CTRL_AGENT_HTTP_SERVICE_STARTED = "CTRL_AGENT_HTTP_SERVICE_STARTED";
@@ -29,6 +30,7 @@ const char* values[] = {
     "CTRL_AGENT_COMMAND_FORWARD_FAILED", "failed forwarding command %1: %2",
     "CTRL_AGENT_CONFIG_CHECK_FAIL", "Control Agent configuration check failed: %1",
     "CTRL_AGENT_CONFIG_FAIL", "Control Agent configuration failed: %1",
+    "CTRL_AGENT_CONFIG_SYNTAX_WARNING", "Control Agent configuration syntax warning: %1",
     "CTRL_AGENT_FAILED", "application experienced a fatal error: %1",
     "CTRL_AGENT_HTTPS_SERVICE_STARTED", "HTTPS service bound to address %1:%2",
     "CTRL_AGENT_HTTP_SERVICE_STARTED", "HTTP service bound to address %1:%2",
diff --git a/src/bin/agent/ca_messages.h b/src/bin/agent/ca_messages.h
index b72eca5896..7e23243007 100644
--- a/src/bin/agent/ca_messages.h
+++ b/src/bin/agent/ca_messages.h
@@ -13,6 +13,7 @@ extern const isc::log::MessageID CTRL_AGENT_COMMAND_FORWARD_BEGIN;
 extern const isc::log::MessageID CTRL_AGENT_COMMAND_FORWARD_FAILED;
 extern const isc::log::MessageID CTRL_AGENT_CONFIG_CHECK_FAIL;
 extern const isc::log::MessageID CTRL_AGENT_CONFIG_FAIL;
+extern const isc::log::MessageID CTRL_AGENT_CONFIG_SYNTAX_WARNING;
 extern const isc::log::MessageID CTRL_AGENT_FAILED;
 extern const isc::log::MessageID CTRL_AGENT_HTTPS_SERVICE_STARTED;
 extern const isc::log::MessageID CTRL_AGENT_HTTP_SERVICE_STARTED;
diff --git a/src/bin/agent/ca_messages.mes b/src/bin/agent/ca_messages.mes
index 7c93f8729d..ca6ef7d7a9 100644
--- a/src/bin/agent/ca_messages.mes
+++ b/src/bin/agent/ca_messages.mes
@@ -29,6 +29,10 @@ This error message indicates that the CA had failed configuration
 attempt. Details are provided. Additional details may be available
 in earlier log entries, possibly on lower levels.
 
+% CTRL_AGENT_CONFIG_SYNTAX_WARNING Control Agent configuration syntax warning: %1
+This warning message indicates that the CA configuration had a minor syntax
+error. The error was displayed and the configuration parsing resumed.
+
 % CTRL_AGENT_FAILED application experienced a fatal error: %1
 This is a fatal error message issued when the Control Agent application
 encounters an unrecoverable error from within the event loop.
diff --git a/src/bin/agent/parser_context.cc b/src/bin/agent/parser_context.cc
index a051679ecd..e7b6043b17 100644
--- a/src/bin/agent/parser_context.cc
+++ b/src/bin/agent/parser_context.cc
@@ -1,4 +1,4 @@
-// Copyright (C) 2017-2020 Internet Systems Consortium, Inc. ("ISC")
+// Copyright (C) 2017-2021 Internet Systems Consortium, Inc. ("ISC")
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -8,10 +8,12 @@
 
 #include <agent/parser_context.h>
 #include <agent/agent_parser.h>
+#include <agent/ca_log.h>
 #include <exceptions/exceptions.h>
 #include <cc/dhcp_config_error.h>
 #include <cc/data.h>
 #include <fstream>
+#include <sstream>
 #include <limits>
 
 namespace isc {
@@ -186,13 +188,11 @@ ParserContext::contextName()
 
 void
 ParserContext::warning(const isc::agent::location& loc,
-                       const std::string& what,
-                       size_t pos /* = 0 */) {
-    if (pos == 0) {
-        std::cerr << loc << ": " << what << std::endl;
-    } else {
-        std::cerr << loc << " (near " << pos << "): " << what << std::endl;
-    }
+                       const std::string& what) {
+    std::ostringstream msg;
+    msg << loc << ": " << what;
+    LOG_WARN(agent_logger, CTRL_AGENT_CONFIG_SYNTAX_WARNING)
+        .arg(msg.str());
 }
 
 } // end of isc::eval namespace
diff --git a/src/bin/agent/parser_context.h b/src/bin/agent/parser_context.h
index b7f5104ff1..026c21cbba 100644
--- a/src/bin/agent/parser_context.h
+++ b/src/bin/agent/parser_context.h
@@ -1,4 +1,4 @@
-// Copyright (C) 2017-2020 Internet Systems Consortium, Inc. ("ISC")
+// Copyright (C) 2017-2021 Internet Systems Consortium, Inc. ("ISC")
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -181,14 +181,9 @@ public:
     ///
     /// @param loc location within the parsed file where the problem was experienced
     /// @param what string explaining the nature of the error
-    /// @param pos optional position for in string errors. The optional position
-    /// for an error in a string begins by 1 so the caller should add 1 to the
-    /// position of the C++ string.
     ///
     /// @throw ParseError
-    void warning(const isc::agent::location& loc,
-                 const std::string& what,
-                 size_t pos = 0);
+    void warning(const isc::agent::location& loc, const std::string& what);
 
     /// @brief Defines syntactic contexts for lexical tie-ins
     typedef enum {
diff --git a/src/bin/d2/parser_context.cc b/src/bin/d2/parser_context.cc
index 8f0f4dbe7b..833d6cf840 100644
--- a/src/bin/d2/parser_context.cc
+++ b/src/bin/d2/parser_context.cc
@@ -8,10 +8,12 @@
 
 #include <d2/d2_parser.h>
 #include <d2/parser_context.h>
+#include <d2srv/d2_log.h>
 #include <exceptions/exceptions.h>
 #include <cc/data.h>
 #include <boost/lexical_cast.hpp>
 #include <fstream>
+#include <sstream>
 #include <limits>
 
 namespace isc {
@@ -203,13 +205,11 @@ D2ParserContext::contextName()
 
 void
 D2ParserContext::warning(const isc::d2::location& loc,
-                         const std::string& what,
-                         size_t pos /* = 0 */) {
-    if (pos == 0) {
-        std::cerr << loc << ": " << what << std::endl;
-    } else {
-        std::cerr << loc << " (near " << pos << "): " << what << std::endl;
-    }
+                         const std::string& what) {
+    std::ostringstream msg;
+    msg << loc << ": " << what;
+    LOG_WARN(d2_to_dns_logger, DHCP_DDNS_CONFIG_SYNTAX_WARNING)
+        .arg(msg.str());
 }
 
 }  // namespace d2
diff --git a/src/bin/d2/parser_context.h b/src/bin/d2/parser_context.h
index a5a00ba780..cd5851a3ef 100644
--- a/src/bin/d2/parser_context.h
+++ b/src/bin/d2/parser_context.h
@@ -199,14 +199,9 @@ public:
     ///
     /// @param loc location within the parsed file where the problem was experienced
     /// @param what string explaining the nature of the error
-    /// @param pos optional position for in string errors. The optional position
-    /// for an error in a string begins by 1 so the caller should add 1 to the
-    /// position of the C++ string.
     ///
     /// @throw ParseError
-    void warning(const isc::d2::location& loc,
-                 const std::string& what,
-                 size_t pos = 0);
+    void warning(const isc::d2::location& loc, const std::string& what);
 
     /// @brief Defines syntactic contexts for lexical tie-ins
     typedef enum {
diff --git a/src/bin/dhcp4/dhcp4_messages.cc b/src/bin/dhcp4/dhcp4_messages.cc
index 24f6704d3d..5fe35d6e12 100644
--- a/src/bin/dhcp4/dhcp4_messages.cc
+++ b/src/bin/dhcp4/dhcp4_messages.cc
@@ -36,6 +36,7 @@ extern const isc::log::MessageID DHCP4_CONFIG_OPTION_DUPLICATE = "DHCP4_CONFIG_O
 extern const isc::log::MessageID DHCP4_CONFIG_PACKET_QUEUE = "DHCP4_CONFIG_PACKET_QUEUE";
 extern const isc::log::MessageID DHCP4_CONFIG_RECEIVED = "DHCP4_CONFIG_RECEIVED";
 extern const isc::log::MessageID DHCP4_CONFIG_START = "DHCP4_CONFIG_START";
+extern const isc::log::MessageID DHCP4_CONFIG_SYNTAX_WARNING = "DHCP4_CONFIG_SYNTAX_WARNING";
 extern const isc::log::MessageID DHCP4_CONFIG_UNRECOVERABLE_ERROR = "DHCP4_CONFIG_UNRECOVERABLE_ERROR";
 extern const isc::log::MessageID DHCP4_CONFIG_UNSUPPORTED_OBJECT = "DHCP4_CONFIG_UNSUPPORTED_OBJECT";
 extern const isc::log::MessageID DHCP4_CONFIG_UPDATE = "DHCP4_CONFIG_UPDATE";
@@ -193,6 +194,7 @@ const char* values[] = {
     "DHCP4_CONFIG_PACKET_QUEUE", "DHCPv4 packet queue info after configuration: %1",
     "DHCP4_CONFIG_RECEIVED", "received configuration %1",
     "DHCP4_CONFIG_START", "DHCPv4 server is processing the following configuration: %1",
+    "DHCP4_CONFIG_SYNTAX_WARNING", "configuration syntax warning: %1",
     "DHCP4_CONFIG_UNRECOVERABLE_ERROR", "DHCPv4 server new configuration failed with an error which cannot be recovered",
     "DHCP4_CONFIG_UNSUPPORTED_OBJECT", "DHCPv4 server configuration includes an unsupported object: %1",
     "DHCP4_CONFIG_UPDATE", "updated configuration received: %1",
diff --git a/src/bin/dhcp4/dhcp4_messages.h b/src/bin/dhcp4/dhcp4_messages.h
index 59b7531bf0..d7ff4219e0 100644
--- a/src/bin/dhcp4/dhcp4_messages.h
+++ b/src/bin/dhcp4/dhcp4_messages.h
@@ -37,6 +37,7 @@ extern const isc::log::MessageID DHCP4_CONFIG_OPTION_DUPLICATE;
 extern const isc::log::MessageID DHCP4_CONFIG_PACKET_QUEUE;
 extern const isc::log::MessageID DHCP4_CONFIG_RECEIVED;
 extern const isc::log::MessageID DHCP4_CONFIG_START;
+extern const isc::log::MessageID DHCP4_CONFIG_SYNTAX_WARNING;
 extern const isc::log::MessageID DHCP4_CONFIG_UNRECOVERABLE_ERROR;
 extern const isc::log::MessageID DHCP4_CONFIG_UNSUPPORTED_OBJECT;
 extern const isc::log::MessageID DHCP4_CONFIG_UPDATE;
diff --git a/src/bin/dhcp4/dhcp4_messages.mes b/src/bin/dhcp4/dhcp4_messages.mes
index 7419027d2c..7c67abdf51 100644
--- a/src/bin/dhcp4/dhcp4_messages.mes
+++ b/src/bin/dhcp4/dhcp4_messages.mes
@@ -178,6 +178,10 @@ This is a debug message that is issued every time the server receives a
 configuration. That happens at start up and also when a server configuration
 change is committed by the administrator.
 
+% DHCP4_CONFIG_SYNTAX_WARNING configuration syntax warning: %1
+This warning message indicates that the DHCPv4 configuration had a minor
+syntax error. The error was displayed and the configuration parsing resumed.
+
 % DHCP4_CONFIG_UNRECOVERABLE_ERROR DHCPv4 server new configuration failed with an error which cannot be recovered
 This fatal error message is issued when a new configuration raised an error
 which cannot be recovered. A correct configuration must be applied as soon
diff --git a/src/bin/dhcp4/parser_context.cc b/src/bin/dhcp4/parser_context.cc
index e909d0e61c..571fba3248 100644
--- a/src/bin/dhcp4/parser_context.cc
+++ b/src/bin/dhcp4/parser_context.cc
@@ -8,10 +8,12 @@
 
 #include <dhcp4/parser_context.h>
 #include <dhcp4/dhcp4_parser.h>
+#include <dhcp4/dhcp4_log.h>
 #include <exceptions/exceptions.h>
 #include <cc/data.h>
 #include <boost/lexical_cast.hpp>
 #include <fstream>
+#include <sstream>
 #include <limits>
 
 namespace isc {
@@ -226,13 +228,11 @@ Parser4Context::contextName() {
 
 void
 Parser4Context::warning(const isc::dhcp::location& loc,
-                        const std::string& what,
-                        size_t pos /* = 0 */) {
-    if (pos == 0) {
-        std::cerr << loc << ": " << what << std::endl;
-    } else {
-        std::cerr << loc << " (near " << pos << "): " << what << std::endl;
-    }
+                        const std::string& what) {
+    std::ostringstream msg;
+    msg << loc << ": " << what;
+    LOG_WARN(dhcp4_logger, DHCP4_CONFIG_SYNTAX_WARNING)
+        .arg(msg.str());
 }
 
 }  // namespace dhcp
diff --git a/src/bin/dhcp4/parser_context.h b/src/bin/dhcp4/parser_context.h
index 787b85e532..2cf8f2d645 100644
--- a/src/bin/dhcp4/parser_context.h
+++ b/src/bin/dhcp4/parser_context.h
@@ -215,14 +215,9 @@ public:
     ///
     /// @param loc location within the parsed file where the problem was experienced
     /// @param what string explaining the nature of the error
-    /// @param pos optional position for in string errors. The optional position
-    /// for an error in a string begins by 1 so the caller should add 1 to the
-    /// position of the C++ string.
     ///
     /// @throw ParseError
-    void warning(const isc::dhcp::location& loc,
-                 const std::string& what,
-                 size_t pos = 0);
+    void warning(const isc::dhcp::location& loc, const std::string& what);
 
     /// @brief Defines syntactic contexts for lexical tie-ins
     typedef enum {
diff --git a/src/bin/dhcp6/dhcp6_messages.cc b/src/bin/dhcp6/dhcp6_messages.cc
index b249d9b5a1..9d203b96e1 100644
--- a/src/bin/dhcp6/dhcp6_messages.cc
+++ b/src/bin/dhcp6/dhcp6_messages.cc
@@ -27,6 +27,7 @@ extern const isc::log::MessageID DHCP6_CONFIG_LOAD_FAIL = "DHCP6_CONFIG_LOAD_FAI
 extern const isc::log::MessageID DHCP6_CONFIG_PACKET_QUEUE = "DHCP6_CONFIG_PACKET_QUEUE";
 extern const isc::log::MessageID DHCP6_CONFIG_RECEIVED = "DHCP6_CONFIG_RECEIVED";
 extern const isc::log::MessageID DHCP6_CONFIG_START = "DHCP6_CONFIG_START";
+extern const isc::log::MessageID DHCP6_CONFIG_SYNTAX_WARNING = "DHCP6_CONFIG_SYNTAX_WARNING";
 extern const isc::log::MessageID DHCP6_CONFIG_UNRECOVERABLE_ERROR = "DHCP6_CONFIG_UNRECOVERABLE_ERROR";
 extern const isc::log::MessageID DHCP6_CONFIG_UNSUPPORTED_OBJECT = "DHCP6_CONFIG_UNSUPPORTED_OBJECT";
 extern const isc::log::MessageID DHCP6_CONFIG_UPDATE = "DHCP6_CONFIG_UPDATE";
@@ -184,6 +185,7 @@ const char* values[] = {
     "DHCP6_CONFIG_PACKET_QUEUE", "DHCPv6 packet queue info after configuration: %1",
     "DHCP6_CONFIG_RECEIVED", "received configuration: %1",
     "DHCP6_CONFIG_START", "DHCPv6 server is processing the following configuration: %1",
+    "DHCP6_CONFIG_SYNTAX_WARNING", "configuration syntax warning: %1",
     "DHCP6_CONFIG_UNRECOVERABLE_ERROR", "DHCPv6 server new configuration failed with an error which cannot be recovered",
     "DHCP6_CONFIG_UNSUPPORTED_OBJECT", "DHCPv6 server configuration includes an unsupported object: %1",
     "DHCP6_CONFIG_UPDATE", "updated configuration received: %1",
diff --git a/src/bin/dhcp6/dhcp6_messages.h b/src/bin/dhcp6/dhcp6_messages.h
index 6c2bf24085..4325f1274a 100644
--- a/src/bin/dhcp6/dhcp6_messages.h
+++ b/src/bin/dhcp6/dhcp6_messages.h
@@ -28,6 +28,7 @@ extern const isc::log::MessageID DHCP6_CONFIG_LOAD_FAIL;
 extern const isc::log::MessageID DHCP6_CONFIG_PACKET_QUEUE;
 extern const isc::log::MessageID DHCP6_CONFIG_RECEIVED;
 extern const isc::log::MessageID DHCP6_CONFIG_START;
+extern const isc::log::MessageID DHCP6_CONFIG_SYNTAX_WARNING;
 extern const isc::log::MessageID DHCP6_CONFIG_UNRECOVERABLE_ERROR;
 extern const isc::log::MessageID DHCP6_CONFIG_UNSUPPORTED_OBJECT;
 extern const isc::log::MessageID DHCP6_CONFIG_UPDATE;
diff --git a/src/bin/dhcp6/dhcp6_messages.mes b/src/bin/dhcp6/dhcp6_messages.mes
index 132ea0b5dd..07b8a0f22e 100644
--- a/src/bin/dhcp6/dhcp6_messages.mes
+++ b/src/bin/dhcp6/dhcp6_messages.mes
@@ -123,6 +123,10 @@ This is a debug message that is issued every time the server receives a
 configuration. That happens start up and also when a server configuration
 change is committed by the administrator.
 
+% DHCP6_CONFIG_SYNTAX_WARNING configuration syntax warning: %1
+This warning message indicates that the DHCPv6 configuration had a minor
+syntax error. The error was displayed and the configuration parsing resumed.
+
 % DHCP6_CONFIG_UNRECOVERABLE_ERROR DHCPv6 server new configuration failed with an error which cannot be recovered
 This fatal error message is issued when a new configuration raised an error
 which cannot be recovered. A correct configuration must be applied as soon
diff --git a/src/bin/dhcp6/parser_context.cc b/src/bin/dhcp6/parser_context.cc
index 7a434df06f..7e26be794d 100644
--- a/src/bin/dhcp6/parser_context.cc
+++ b/src/bin/dhcp6/parser_context.cc
@@ -8,10 +8,12 @@
 
 #include <dhcp6/parser_context.h>
 #include <dhcp6/dhcp6_parser.h>
+#include <dhcp6/dhcp6_log.h>
 #include <exceptions/exceptions.h>
 #include <cc/data.h>
 #include <boost/lexical_cast.hpp>
 #include <fstream>
+#include <sstream>
 #include <limits>
 
 namespace isc {
@@ -227,13 +229,11 @@ Parser6Context::contextName() {
 
 void
 Parser6Context::warning(const isc::dhcp::location& loc,
-                        const std::string& what,
-                        size_t pos /* = 0 */) {
-    if (pos == 0) {
-        std::cerr << loc << ": " << what << std::endl;
-    } else {
-        std::cerr << loc << " (near " << pos << "): " << what << std::endl;
-    }
+                        const std::string& what) {
+    std::ostringstream msg;
+    msg << loc << ": " << what;
+    LOG_WARN(dhcp6_logger, DHCP6_CONFIG_SYNTAX_WARNING)
+        .arg(msg.str());
 }
 
 }  // namespace dhcp
diff --git a/src/bin/dhcp6/parser_context.h b/src/bin/dhcp6/parser_context.h
index 27d330b4de..ff31dc8276 100644
--- a/src/bin/dhcp6/parser_context.h
+++ b/src/bin/dhcp6/parser_context.h
@@ -218,14 +218,9 @@ public:
     ///
     /// @param loc location within the parsed file where the problem was experienced
     /// @param what string explaining the nature of the error
-    /// @param pos optional position for in string errors. The optional position
-    /// for an error in a string begins by 1 so the caller should add 1 to the
-    /// position of the C++ string.
     ///
     /// @throw ParseError
-    void warning(const isc::dhcp::location& loc,
-                 const std::string& what,
-                 size_t pos = 0);
+    void warning(const isc::dhcp::location& loc, const std::string& what);
 
     /// @brief Defines syntactic contexts for lexical tie-ins
     typedef enum {
diff --git a/src/bin/netconf/netconf_messages.cc b/src/bin/netconf/netconf_messages.cc
index c6c4aa64c6..8464ef777c 100644
--- a/src/bin/netconf/netconf_messages.cc
+++ b/src/bin/netconf/netconf_messages.cc
@@ -1,4 +1,4 @@
-// File created from ../../../src/bin/netconf/netconf_messages.mes
+// File created from netconf_messages.mes
 
 #include <cstddef>
 #include <log/message_types.h>
@@ -12,6 +12,7 @@ extern const isc::log::MessageID NETCONF_CONFIG_CHANGED_DETAIL = "NETCONF_CONFIG
 extern const isc::log::MessageID NETCONF_CONFIG_CHANGE_EVENT = "NETCONF_CONFIG_CHANGE_EVENT";
 extern const isc::log::MessageID NETCONF_CONFIG_CHECK_FAIL = "NETCONF_CONFIG_CHECK_FAIL";
 extern const isc::log::MessageID NETCONF_CONFIG_FAIL = "NETCONF_CONFIG_FAIL";
+extern const isc::log::MessageID NETCONF_CONFIG_SYNTAX_WARNING = "NETCONF_CONFIG_SYNTAX_WARNING";
 extern const isc::log::MessageID NETCONF_FAILED = "NETCONF_FAILED";
 extern const isc::log::MessageID NETCONF_GET_CONFIG = "NETCONF_GET_CONFIG";
 extern const isc::log::MessageID NETCONF_GET_CONFIG_FAILED = "NETCONF_GET_CONFIG_FAILED";
@@ -52,6 +53,7 @@ const char* values[] = {
     "NETCONF_CONFIG_CHANGE_EVENT", "Received YANG configuration change %1 event",
     "NETCONF_CONFIG_CHECK_FAIL", "Netconf configuration check failed: %1",
     "NETCONF_CONFIG_FAIL", "Netconf configuration failed: %1",
+    "NETCONF_CONFIG_SYNTAX_WARNING", "Netconf configuration syntax warning: %1",
     "NETCONF_FAILED", "application experienced a fatal error: %1",
     "NETCONF_GET_CONFIG", "got configuration from %1 server: %2",
     "NETCONF_GET_CONFIG_FAILED", "getting configuration from %1 server failed: %2",
diff --git a/src/bin/netconf/netconf_messages.h b/src/bin/netconf/netconf_messages.h
index cdec3995f5..7ca4abc211 100644
--- a/src/bin/netconf/netconf_messages.h
+++ b/src/bin/netconf/netconf_messages.h
@@ -1,4 +1,4 @@
-// File created from ../../../src/bin/netconf/netconf_messages.mes
+// File created from netconf_messages.mes
 
 #ifndef NETCONF_MESSAGES_H
 #define NETCONF_MESSAGES_H
@@ -13,6 +13,7 @@ extern const isc::log::MessageID NETCONF_CONFIG_CHANGED_DETAIL;
 extern const isc::log::MessageID NETCONF_CONFIG_CHANGE_EVENT;
 extern const isc::log::MessageID NETCONF_CONFIG_CHECK_FAIL;
 extern const isc::log::MessageID NETCONF_CONFIG_FAIL;
+extern const isc::log::MessageID NETCONF_CONFIG_SYNTAX_WARNING;
 extern const isc::log::MessageID NETCONF_FAILED;
 extern const isc::log::MessageID NETCONF_GET_CONFIG;
 extern const isc::log::MessageID NETCONF_GET_CONFIG_FAILED;
diff --git a/src/bin/netconf/netconf_messages.mes b/src/bin/netconf/netconf_messages.mes
index 3619929e0e..7883c1d8a8 100644
--- a/src/bin/netconf/netconf_messages.mes
+++ b/src/bin/netconf/netconf_messages.mes
@@ -29,6 +29,10 @@ This error message indicates that Netconf had failed configuration
 attempt. Details are provided. Additional details may be available
 in earlier log entries, possibly on lower levels.
 
+% NETCONF_CONFIG_SYNTAX_WARNING Netconf configuration syntax warning: %1
+This warning message indicates that the Netconf configuration had a minor
+syntax error. The error was displayed and the configuration parsing resumed.
+
 % NETCONF_FAILED application experienced a fatal error: %1
 This is a fatal error message issued when the Netconf application
 got an unrecoverable error from within the event loop.
diff --git a/src/bin/netconf/parser_context.cc b/src/bin/netconf/parser_context.cc
index c672d95226..e57b4c51ac 100644
--- a/src/bin/netconf/parser_context.cc
+++ b/src/bin/netconf/parser_context.cc
@@ -1,4 +1,4 @@
-// Copyright (C) 2018-2020 Internet Systems Consortium, Inc. ("ISC")
+// Copyright (C) 2018-2021 Internet Systems Consortium, Inc. ("ISC")
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -8,10 +8,12 @@
 
 #include <netconf/parser_context.h>
 #include <netconf/netconf_parser.h>
+#include <netconf/netconf_log.h>
 #include <exceptions/exceptions.h>
 //#include <cc/dhcp_config_error.h>
 #include <cc/data.h>
 #include <fstream>
+#include <sstream>
 #include <limits>
 
 namespace isc {
@@ -182,13 +184,11 @@ ParserContext::contextName()
 
 void
 ParserContext::warning(const isc::netconf::location& loc,
-                       const std::string& what,
-                       size_t pos /* = 0 */) {
-    if (pos == 0) {
-        std::cerr << loc << ": " << what << std::endl;
-    } else {
-        std::cerr << loc << " (near " << pos << "): " << what << std::endl;
-    }
+                       const std::string& what) {
+    std::ostringstream msg;
+    msg << loc << ": " << what;
+    LOG_WARN(netconf_logger, NETCONF_CONFIG_SYNTAX_WARNING)
+        .arg(msg.str());
 }
 
 }  // namespace netconf
diff --git a/src/bin/netconf/parser_context.h b/src/bin/netconf/parser_context.h
index 5db590fff0..32a39245d0 100644
--- a/src/bin/netconf/parser_context.h
+++ b/src/bin/netconf/parser_context.h
@@ -1,4 +1,4 @@
-// Copyright (C) 2018-2020 Internet Systems Consortium, Inc. ("ISC")
+// Copyright (C) 2018-2021 Internet Systems Consortium, Inc. ("ISC")
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -182,14 +182,9 @@ public:
     ///
     /// @param loc location within the parsed file where the problem was experienced
     /// @param what string explaining the nature of the error
-    /// @param pos optional position for in string errors. The optional position
-    /// for an error in a string begins by 1 so the caller should add 1 to the
-    /// position of the C++ string.
     ///
     /// @throw ParseError
-    void warning(const isc::netconf::location& loc,
-                 const std::string& what,
-                 size_t pos = 0);
+    void warning(const isc::netconf::location& loc, const std::string& what);
 
     /// @brief Defines syntactic contexts for lexical tie-ins
     typedef enum {
diff --git a/src/lib/d2srv/d2_messages.cc b/src/lib/d2srv/d2_messages.cc
index 74b7d14bf4..9fd85e0a53 100644
--- a/src/lib/d2srv/d2_messages.cc
+++ b/src/lib/d2srv/d2_messages.cc
@@ -17,6 +17,7 @@ extern const isc::log::MessageID DHCP_DDNS_CONFIGURE = "DHCP_DDNS_CONFIGURE";
 extern const isc::log::MessageID DHCP_DDNS_CONFIGURED_CALLOUT_DROP = "DHCP_DDNS_CONFIGURED_CALLOUT_DROP";
 extern const isc::log::MessageID DHCP_DDNS_CONFIG_CHECK_FAIL = "DHCP_DDNS_CONFIG_CHECK_FAIL";
 extern const isc::log::MessageID DHCP_DDNS_CONFIG_FAIL = "DHCP_DDNS_CONFIG_FAIL";
+extern const isc::log::MessageID DHCP_DDNS_CONFIG_SYNTAX_WARNING = "DHCP_DDNS_CONFIG_SYNTAX_WARNING";
 extern const isc::log::MessageID DHCP_DDNS_FAILED = "DHCP_DDNS_FAILED";
 extern const isc::log::MessageID DHCP_DDNS_FORWARD_ADD_BAD_DNSCLIENT_STATUS = "DHCP_DDNS_FORWARD_ADD_BAD_DNSCLIENT_STATUS";
 extern const isc::log::MessageID DHCP_DDNS_FORWARD_ADD_BUILD_FAILURE = "DHCP_DDNS_FORWARD_ADD_BUILD_FAILURE";
@@ -99,6 +100,7 @@ const char* values[] = {
     "DHCP_DDNS_CONFIGURED_CALLOUT_DROP", "configuration was rejected because a callout set the next step to 'drop': %1",
     "DHCP_DDNS_CONFIG_CHECK_FAIL", "DHCP-DDNS server configuration check failed: %1",
     "DHCP_DDNS_CONFIG_FAIL", "DHCP-DDNS server configuration failed: %1",
+    "DHCP_DDNS_CONFIG_SYNTAX_WARNING", "DHCP-DDNS server configuration syntax warning: %1",
     "DHCP_DDNS_FAILED", "application experienced a fatal error: %1",
     "DHCP_DDNS_FORWARD_ADD_BAD_DNSCLIENT_STATUS", "DHCP_DDNS Request ID %1: received an unknown DNSClient status: %2, while adding a forward address mapping for FQDN %3 to DNS server %4",
     "DHCP_DDNS_FORWARD_ADD_BUILD_FAILURE", "DNS Request ID %1:  update message to add a forward DNS entry could not be constructed for this request: %2, reason: %3",
diff --git a/src/lib/d2srv/d2_messages.h b/src/lib/d2srv/d2_messages.h
index cfa5c3fe2f..cb1a95a089 100644
--- a/src/lib/d2srv/d2_messages.h
+++ b/src/lib/d2srv/d2_messages.h
@@ -18,6 +18,7 @@ extern const isc::log::MessageID DHCP_DDNS_CONFIGURE;
 extern const isc::log::MessageID DHCP_DDNS_CONFIGURED_CALLOUT_DROP;
 extern const isc::log::MessageID DHCP_DDNS_CONFIG_CHECK_FAIL;
 extern const isc::log::MessageID DHCP_DDNS_CONFIG_FAIL;
+extern const isc::log::MessageID DHCP_DDNS_CONFIG_SYNTAX_WARNING;
 extern const isc::log::MessageID DHCP_DDNS_FAILED;
 extern const isc::log::MessageID DHCP_DDNS_FORWARD_ADD_BAD_DNSCLIENT_STATUS;
 extern const isc::log::MessageID DHCP_DDNS_FORWARD_ADD_BUILD_FAILURE;
diff --git a/src/lib/d2srv/d2_messages.mes b/src/lib/d2srv/d2_messages.mes
index 75bf8da1aa..b86eb7b634 100644
--- a/src/lib/d2srv/d2_messages.mes
+++ b/src/lib/d2srv/d2_messages.mes
@@ -56,6 +56,10 @@ This error message indicates that the DHCP-DDNS had failed configuration
 attempt. Details are provided. Additional details may be available
 in earlier log entries, possibly on lower levels.
 
+% DHCP_DDNS_CONFIG_SYNTAX_WARNING DHCP-DDNS server configuration syntax warning: %1
+This warning message indicates that the DHCP-DDNS configuration had a minor
+syntax error. The error was displayed and the configuration parsing resumed.
+
 % DHCP_DDNS_FAILED application experienced a fatal error: %1
 This is a debug message issued when the DHCP-DDNS application encounters an
 unrecoverable error from within the event loop.