Problem: some platforms do not have strnlen

Solution: move compat redefinition to compat.hpp header so that
it can be used from msg.cpp

CMakeLists.txt

@@ -1001,6 +1001,7 @@ set(cxx-sources
     client.hpp
     clock.hpp
     command.hpp
+    compat.hpp
     condition_variable.hpp
     config.hpp
     ctx.hpp

Makefile.am

@@ -33,6 +33,7 @@ src_libzmq_la_SOURCES = \
 	src/clock.cpp \
 	src/clock.hpp \
 	src/command.hpp \
+	src/compat.hpp \
 	src/condition_variable.hpp \
 	src/config.hpp \
 	src/ctx.cpp \

builds/gyp/project.gyp

@@ -74,6 +74,7 @@
         '../../src/clock.cpp',
         '../../src/clock.hpp',
         '../../src/command.hpp',
+        '../../src/compat.hpp',
         '../../src/condition_variable.hpp',
         '../../src/config.hpp',
         '../../src/ctx.cpp',

src/compat.hpp

@@ -0,0 +1,73 @@
+/*
+    Copyright (c) 2020 Contributors as noted in the AUTHORS file
+
+    This file is part of libzmq, the ZeroMQ core engine in C++.
+
+    libzmq is free software; you can redistribute it and/or modify it under
+    the terms of the GNU Lesser General Public License (LGPL) as published
+    by the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    As a special exception, the Contributors give you permission to link
+    this library with independent modules to produce an executable,
+    regardless of the license terms of these independent modules, and to
+    copy and distribute the resulting executable under terms of your choice,
+    provided that you also meet, for each linked independent module, the
+    terms and conditions of the license of that module. An independent
+    module is a module which is not derived from or based on this library.
+    If you modify this library, you must extend this exception to your
+    version of the library.
+
+    libzmq is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+    License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef __ZMQ_COMPAT_HPP_INCLUDED__
+#define __ZMQ_COMPAT_HPP_INCLUDED__
+
+#include "precompiled.hpp"
+#include <string.h>
+
+#ifdef ZMQ_HAVE_WINDOWS
+#define strcasecmp _stricmp
+#define strtok_r strtok_s
+#else
+#ifdef ZMQ_HAVE_LIBBSD
+#include <bsd/string.h>
+#elif !defined(ZMQ_HAVE_STRLCPY)
+static inline size_t
+strlcpy (char *dest_, const char *src_, const size_t dest_size_)
+{
+    size_t remain = dest_size_;
+    for (; remain && *src_; --remain, ++src_, ++dest_) {
+        *dest_ = *src_;
+    }
+    return dest_size_ - remain;
+}
+#endif
+template <size_t size>
+static inline int strcpy_s (char (&dest_)[size], const char *const src_)
+{
+    const size_t res = strlcpy (dest_, src_, size);
+    return res >= size ? ERANGE : 0;
+}
+#endif
+
+#ifndef HAVE_STRNLEN
+static inline size_t strnlen (const char *s, size_t len)
+{
+    for (size_t i = 0; i < len; i++) {
+        if (s[i] == '\0')
+            return i + 1;
+    }
+
+    return len;
+}
+#endif
+
+#endif

src/ipc_address.cpp

@@ -28,6 +28,7 @@
 */
 
 #include "precompiled.hpp"
+#include "compat.hpp"
 #include "ipc_address.hpp"
 
 #if defined ZMQ_HAVE_IPC
@@ -36,18 +37,6 @@
 
 #include <string>
 
-#ifndef HAVE_STRNLEN
-static size_t strnlen (const char *s, size_t len)
-{
-    for (size_t i = 0; i < len; i++) {
-        if (s[i] == '\0')
-            return i + 1;
-    }
-
-    return len;
-}
-#endif
-
 zmq::ipc_address_t::ipc_address_t ()
 {
     memset (&_address, 0, sizeof _address);

src/msg.cpp

@@ -28,6 +28,7 @@
 */
 
 #include "precompiled.hpp"
+#include "compat.hpp"
 #include "macros.hpp"
 #include "msg.hpp"
 

src/ws_engine.cpp

@@ -54,6 +54,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #include <cstring>
 
+#include "compat.hpp"
 #include "tcp.hpp"
 #include "ws_engine.hpp"
 #include "session_base.hpp"
@@ -71,30 +72,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "curve_server.hpp"
 #endif
 
-#ifdef ZMQ_HAVE_WINDOWS
-#define strcasecmp _stricmp
-#define strtok_r strtok_s
-#else
-#ifdef ZMQ_HAVE_LIBBSD
-#include <bsd/string.h>
-#elif !defined(ZMQ_HAVE_STRLCPY)
-static size_t strlcpy (char *dest_, const char *src_, const size_t dest_size_)
-{
-    size_t remain = dest_size_;
-    for (; remain && *src_; --remain, ++src_, ++dest_) {
-        *dest_ = *src_;
-    }
-    return dest_size_ - remain;
-}
-#endif
-template <size_t size>
-static int strcpy_s (char (&dest_)[size], const char *const src_)
-{
-    const size_t res = strlcpy (dest_, src_, size);
-    return res >= size ? ERANGE : 0;
-}
-#endif
-
 //  OSX uses a different name for this socket option
 #ifndef IPV6_ADD_MEMBERSHIP
 #define IPV6_ADD_MEMBERSHIP IPV6_JOIN_GROUP