Preliminary build script for Emscripten

dist-build/Makefile.am

@@ -4,6 +4,7 @@ EXTRA_DIST = \
 	android-arm.sh \
 	android-x86.sh \
 	android-mips.sh \
+	emscripten.sh \
 	ios.sh \
 	msys2-win32.sh \
 	msys2-win64.sh

dist-build/emscripten.sh

@@ -0,0 +1,13 @@
+#! /bin/sh
+
+export PREFIX="$(pwd)/libsodium-js"
+export EXPORTED_FUNCTIONS='["_sodium_version_string"]'
+export OPTFLAGS="--llvm-lto 3 -Oz"
+export CFLAGS="$OPTFLAGS --pre-js=test/default/pre.js "
+export LDFLAGS="-s EXPORTED_FUNCTIONS=${EXPORTED_FUNCTIONS}"
+
+emconfigure ./configure --disable-shared --prefix="$PREFIX" && \
+emmake make clean &&
+emmake make install &&
+emcc --closure 1 $OPTFLAGS $LDFLAGS \
+  "${PREFIX}/lib/libsodium.a" -o "${PREFIX}/lib/libsodium.js"