chore: Limit exports in wasm library.

This cuts down the size from 3MB to 1.2MB.

Author: iphydf

cmake/StrictAbi.cmake

@@ -12,15 +12,25 @@
 find_program(SHELL NAMES sh dash bash zsh fish)
 
 macro(make_version_script)
-  if(STRICT_ABI AND SHELL AND ENABLE_SHARED)
+  if(STRICT_ABI AND SHELL)
     _make_version_script(${ARGN})
+
+    if(ENABLE_SHARED)
+      if(APPLE)
+        set_target_properties(${target}_shared PROPERTIES
+          LINK_FLAGS -Wl,-exported_symbols_list,${${target}_VERSION_SCRIPT})
+      else()
+        set_target_properties(${target}_shared PROPERTIES
+          LINK_FLAGS -Wl,--version-script,${${target}_VERSION_SCRIPT})
+      endif()
+    endif()
   endif()
 endmacro()
 
 function(_make_version_script target)
   set(${target}_VERSION_SCRIPT "${CMAKE_BINARY_DIR}/${target}.ld")
 
-  if(NOT APPLE)
+  if(NOT APPLE AND NOT EMSCRIPTEN)
     file(WRITE ${${target}_VERSION_SCRIPT}
       "{ global:\n")
   endif()
@@ -40,29 +50,21 @@ function(_make_version_script target)
     string(REPLACE "\n" ";" sublib_SYMS ${sublib_SYMS})
 
     foreach(sym ${sublib_SYMS})
-      if(APPLE)
+      if(APPLE OR EMSCRIPTEN)
         file(APPEND ${${target}_VERSION_SCRIPT} "_")
       endif()
       file(APPEND ${${target}_VERSION_SCRIPT} "${sym}")
-      if(NOT APPLE)
+      if(NOT APPLE AND NOT EMSCRIPTEN)
         file(APPEND ${${target}_VERSION_SCRIPT} ";")
       endif()
       file(APPEND ${${target}_VERSION_SCRIPT} "\n")
     endforeach(sym)
   endforeach(sublib)
 
-  if(NOT APPLE)
+  if(NOT APPLE AND NOT EMSCRIPTEN)
     file(APPEND ${${target}_VERSION_SCRIPT}
       "local: *; };\n")
   endif()
-
-  if(APPLE)
-    set_target_properties(${target}_shared PROPERTIES
-      LINK_FLAGS -Wl,-exported_symbols_list,${${target}_VERSION_SCRIPT})
-  else()
-    set_target_properties(${target}_shared PROPERTIES
-      LINK_FLAGS -Wl,--version-script,${${target}_VERSION_SCRIPT})
-  endif()
 endfunction()
 
 option(STRICT_ABI "Enforce strict ABI export in dynamic libraries" OFF)

other/docker/wasm/wasm.Dockerfile

@@ -23,8 +23,8 @@ RUN apt-get update && apt-get install --no-install-recommends -y \
 
 WORKDIR /work/emsdk
 RUN git clone --depth=1 https://github.com/emscripten-core/emsdk /work/emsdk \
- && ./emsdk install 4.0.1 \
- && ./emsdk activate 4.0.1
+ && ./emsdk install 4.0.3 \
+ && ./emsdk activate 4.0.3
 
 SHELL ["/bin/bash", "-o", "pipefail", "-c"]
 WORKDIR /work
@@ -84,14 +84,13 @@ RUN . "/work/emsdk/emsdk_env.sh" \
 RUN . "/work/emsdk/emsdk_env.sh" \
  && mkdir -p /wasm/bin \
  && emcc -O3 -flto \
- -s ALLOW_UNIMPLEMENTED_SYSCALLS=1 \
  -s EXPORT_NAME=libtoxcore \
- -s IGNORE_MISSING_MAIN=1 \
  -s MAIN_MODULE=1 \
  -s MALLOC=emmalloc \
  -s MODULARIZE=1 \
  -s STRICT=1 \
  -s WEBSOCKET_URL=ws:// \
+ --no-entry \
  /wasm/lib/libopus.a \
  /wasm/lib/libsodium.a \
  /wasm/lib/libvpx.a \
@@ -108,28 +107,34 @@ RUN . "/work/emsdk/emsdk_env.sh" \
  -GNinja \
  -DCMAKE_INSTALL_PREFIX="/wasm" \
  -DCMAKE_C_FLAGS="-O3 -flto -fPIC" \
+ -DCMAKE_UNITY_BUILD=ON \
  -DMUST_BUILD_TOXAV=ON \
  -DENABLE_SHARED=OFF \
  -DBOOTSTRAP_DAEMON=OFF \
  -DMIN_LOGGER_LEVEL=TRACE \
+ -DSTRICT_ABI=ON \
  . \
  && emmake cmake --build _build \
  && emmake cmake --install _build
 
+RUN echo _malloc >>/work/c-toxcore/_build/toxcore.ld \
+ && echo _free >>/work/c-toxcore/_build/toxcore.ld \
+ && cat /work/c-toxcore/_build/toxcore.ld
+
 # Link together all the libraries.
 RUN . "/work/emsdk/emsdk_env.sh" \
  && mkdir -p /wasm/bin \
  && emcc -O3 -flto \
- -s ALLOW_UNIMPLEMENTED_SYSCALLS=1 \
+ -s EXPORTED_FUNCTIONS="$(sed -e 's/.*/"&"/' /work/c-toxcore/_build/toxcore.ld | paste -sd "," -)" \
  -s EXPORT_NAME=libtoxcore \
- -s IGNORE_MISSING_MAIN=1 \
- -s MAIN_MODULE=1 \
  -s MALLOC=emmalloc \
  -s MODULARIZE=1 \
  -s STRICT=1 \
  -s WEBSOCKET_URL=ws:// \
+ --no-entry \
  /wasm/lib/libopus.a \
  /wasm/lib/libsodium.a \
  /wasm/lib/libvpx.a \
  /wasm/lib/libtoxcore.a \
  -o /wasm/bin/libtoxcore.js
+RUN ls -lh /wasm/bin/libtoxcore.js /wasm/bin/libtoxcore.wasm

toxcore/network.c

@@ -592,7 +592,11 @@ static int sys_getsockopt(void *obj, Socket sock, int level, int optname, void *
 non_null()
 static int sys_setsockopt(void *obj, Socket sock, int level, int optname, const void *optval, size_t optlen)
 {
+#ifdef EMSCRIPTEN
+    return 0;
+#else
     return setsockopt(net_socket_to_native(sock), level, optname, (const char *)optval, optlen);
+#endif
 }
 
 // sets and fills an array of addrs for address