Add flag to consider 'unresolved symbol' as an error.

CMake/Modules/Urho3D-CMake-common.cmake

@@ -738,7 +738,7 @@ macro (setup_emscripten_linker_flags LINKER_FLAGS)
     else ()
         set (MEMORY_LINKER_FLAGS "-s TOTAL_MEMORY=${EMSCRIPTEN_TOTAL_MEMORY}")
     endif ()
-    set (${LINKER_FLAGS} "${${LINKER_FLAGS}} ${MEMORY_LINKER_FLAGS} -s USE_SDL=2")    # Urho3D uses SDL2 so set it here instead of in the toolchain which potentially could be reused in other projects not using SDL2
+    set (${LINKER_FLAGS} "${${LINKER_FLAGS}} ${MEMORY_LINKER_FLAGS} -s USE_SDL=2 -s ERROR_ON_UNDEFINED_SYMBOLS=1")    # Urho3D uses SDL2 so set it here instead of in the toolchain which potentially could be reused in other projects not using SDL2
     set (${LINKER_FLAGS}_DEBUG -g4)     # Preserve LLVM debug information, show line number debug comments, and generate source maps
 endmacro ()
 

Docs/GettingStarted.dox

@@ -226,7 +226,12 @@ This section assumes you have already updated, installed, and activated the late
 
 Set the EMSCRIPTEN_ROOT_PATH environment variable or build option to point to the root path of Emscripten cross-compiler tools. The Emscripten sysroot path will be derived from the root path, usually from 'system' subdir relative to the root path. However, you can optionally set the EMSCRIPTEN_SYSROOT environment variable or build option to point to another system root path.
 
-On Windows host, execute cmake_emscripten.bat. On OS X or Linux host, execute cmake_emscripten.sh. Then go to the build tree and execute the 'make' command to start the build as usual. You may want to set the URHO3D_SAMPLES build option to build all the samples.
+On Windows host, execute cmake_emscripten.bat. On OS X or Linux host, execute cmake_emscripten.sh. Then go to the build tree and execute the 'make' command to start the build as usual. You may want to set the URHO3D_SAMPLES build option to build all the samples. You may also optionally set the URHO3D_LUA build option to enable Lua scripting support. If you encounter "Too many open files" warning when archiving the Urho3D static library, follow by "Unresolved symbol" errors on OS X then you have to increase the soft-limit in your host system before rebuilding the library and all the main targets.
+
+For example, to double the limit (which normally defaults to 256 on OS X):
+\verbatim
+ulimit -Sn 512
+\endverbatim
 
 After the commands finish successfully, the HTMLs and its correspondng data files should have been generated in the build tree's "bin" subdirectory, from where it can be launched in a browser.
 

Source/ThirdParty/Lua/CMakeLists.txt

@@ -33,7 +33,7 @@ setup_library ()
 install_header_files (DIRECTORY src/ DESTINATION ${DEST_INCLUDE_DIR}/ThirdParty/Lua FILES_MATCHING PATTERN *.h)  # Note: the trailing slash is significant
 
 # Setup additional Lua standalone targets (these targets can be transfered and executed on an embedded device, such as Raspberry Pi and Android)
-if (NOT IOS)
+if (NOT IOS AND NOT EMSCRIPTEN)
     # Define target name for Lua interpreter
     set (TARGET_NAME lua_interpreter)   # Note: intended target name is 'lua' which clashes with 'Lua' library target above for case-insensitive platform
 

Source/ThirdParty/LuaJIT/CMakeLists.txt

@@ -404,7 +404,7 @@ setup_library ()
 install_header_files (DIRECTORY src/ DESTINATION ${DEST_INCLUDE_DIR}/ThirdParty/LuaJIT FILES_MATCHING PATTERN *.h *.hpp)  # Note: the trailing slash is significant
 
 # Setup additional Lua standalone target (this target can be transfered and executed on an embedded device, such as Raspberry Pi and Android)
-if (NOT IOS)
+if (NOT IOS AND NOT EMSCRIPTEN)     # LuaJIT library on Emscripten is not possible anyway but just in case it could be in the future, exclude it to build standalone target
     # Define target name for LuaJIT interpreter cum compiler
     set (TARGET_NAME luajit_interpreter)   # Note: intended target name is 'luajit' which clashes with 'LuaJIT' library target above for case-insensitive platform
 

Source/Urho3D/CMakeLists.txt

@@ -71,7 +71,7 @@ if (URHO3D_LUA)
             COMMAND ${CMAKE_BINARY_DIR}/bin/tool/tolua++ -L ToCppHook.lua -o ${CMAKE_CURRENT_BINARY_DIR}/${GEN_CPP_FILE} ${NAME}
             DEPENDS tolua++ ${API_PKG_FILE} ${PKG_FILES} LuaScript/pkgs/ToCppHook.lua
             WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/LuaScript/pkgs
-            COMMENT "Generating tolua++ DIR binding on the fly for ${DIR}")
+            COMMENT "Generating tolua++ API binding on the fly for ${DIR}")
     endforeach ()
 else ()
     list (APPEND EXCLUDED_SOURCE_DIRS LuaScript)