Suppress assert()'s in the production builds.

Change-Id: I2074ed335b7201337e6519440ff6bed1809be915

Makefile.am

@@ -27,6 +27,10 @@ AM_CPPFLAGS = -pthread -DLOOLWSD_DATADIR='"@LOOLWSD_DATADIR@"' \
 	      -DDEBUG_ABSSRCDIR='"@abs_srcdir@"' \
 	      ${include_paths}
 
+if !ENABLE_DEBUG
+AM_CPPFLAGS += -DNDEBUG
+endif
+
 AM_LDFLAGS = -pthread -Wl,-E,-rpath,/snap/loolwsd/current/usr/lib $(ZLIB_LIBS)
 
 if ENABLE_SSL

common/Util.hpp

@@ -77,12 +77,20 @@ namespace Util
     template <typename T>
     void assertIsLocked(const T& lock)
     {
+#ifdef NDEBUG
+        (void) lock;
+#else
         assert(lock.owns_lock());
+#endif
     }
 
     inline void assertIsLocked(std::mutex& mtx)
     {
+#ifdef NDEBUG
+        (void) mtx;
+#else
         assert(!mtx.try_lock());
+#endif
     }
 
     /// Returns the process PSS in KB (works only when we have perms for /proc/pid/smaps).

configure.ac

@@ -246,6 +246,7 @@ AS_IF([test "$enable_ssl" != "no"],
       [AC_DEFINE([ENABLE_SSL],0,[Whether to enable SSL])])
 
 AM_CONDITIONAL([ENABLE_SSL], [test "$enable_ssl" != "no"])
+AM_CONDITIONAL([ENABLE_DEBUG], [test "$ENABLE_DEBUG" = "true"])
 
 ENABLE_SSL=
 if test "$enable_ssl" != "no"; then

net/clientnb.cpp

@@ -144,7 +144,10 @@ struct ThreadWorker : public Runnable
         {
             Session ping(_domain ? _domain : "init", EnableHttps);
             ping.sendPing(i);
-            int back = ping.getResponseInt();
+#ifndef NDEBUG
+            int back =
+#endif
+                ping.getResponseInt();
             assert(back == i + 1);
         }
     }
@@ -209,7 +212,10 @@ struct Client : public Poco::Util::Application
             ws->sendFrame(&i, sizeof(i), WebSocket::SendFlags::FRAME_BINARY);
             size_t back[5];
             int flags = 0;
-            int recvd = ws->receiveFrame((void *)back, sizeof(back), flags);
+#ifndef NDEBUG
+            int recvd =
+#endif
+                ws->receiveFrame((void *)back, sizeof(back), flags);
             assert(recvd == sizeof(size_t));
             assert(back[0] == i + 1);
         }
@@ -233,7 +239,10 @@ struct Client : public Poco::Util::Application
 
             res.resize(i);
             int flags;
-            int recvd = ws->receiveFrame(res.data(), res.size(), flags);
+#ifndef NDEBUG
+            int recvd =
+#endif
+                ws->receiveFrame(res.data(), res.size(), flags);
             assert(recvd == static_cast<int>(i));
 
             if (i == sizeof(size_t))