feat: Build the fun utils when cross-compiling to Windows

While fun utils are of very low quality, both code-wise and usage-wise
-- not checking for failed mallocs, not offering usage instructions,
etc., there are a couple of them that Windows users might find useful,
like the vanity key generators or a savedata creator, for example.

The building of the fun utils was broken on Windows due to the utils
failing to find sodium.h, as no libsodium include dirs were set on the
fun utils.

Author: nurupo

other/docker/windows/build_toxcore.sh

@@ -77,11 +77,14 @@ build() {
     -DENABLE_STATIC=ON \
     -DSTRICT_ABI=ON \
     -DEXPERIMENTAL_API=ON \
+    -DBUILD_FUN_UTILS=ON \
     -DCMAKE_EXE_LINKER_FLAGS="-static" \
     -DCMAKE_SHARED_LINKER_FLAGS="-static" \
     "${EXTRA_CMAKE_FLAGS_ARRAY[@]}" \
     -S ..
   cmake --build . --target install --parallel "$(nproc)"
+  # CMake doesn't install fun utils, so do it manually
+  cp -a other/fun/*.exe "$RESULT_PREFIX_DIR/bin/"
 
   if [ "$ENABLE_TEST" = "true" ]; then
     rm -rf /root/.wine

other/fun/CMakeLists.txt

@@ -6,36 +6,48 @@ function(target_link_toxcore target)
   endif()
 endfunction()
 
+function(target_link_sodium target)
+  if(TARGET unofficial-sodium::sodium)
+    target_link_libraries(${target} PRIVATE unofficial-sodium::sodium)
+  else()
+    target_link_libraries(${target} PRIVATE ${LIBSODIUM_LIBRARIES})
+    target_link_directories(${target} PRIVATE ${LIBSODIUM_LIBRARY_DIRS})
+    target_include_directories(${target} SYSTEM PRIVATE ${LIBSODIUM_INCLUDE_DIRS})
+    target_compile_options(${target} PRIVATE ${LIBSODIUM_CFLAGS_OTHER})
+  endif()
+endfunction()
+
 add_executable(save-generator save-generator.c)
 target_link_libraries(save-generator PRIVATE misc_tools)
 target_link_toxcore(save-generator)
 
 add_executable(strkey strkey.c)
-target_link_libraries(strkey PRIVATE ${LIBSODIUM_LIBRARIES})
-target_link_toxcore(strkey)
+target_link_sodium(strkey)
 
 add_executable(create_bootstrap_keys create_bootstrap_keys.c)
-target_link_libraries(create_bootstrap_keys PRIVATE ${LIBSODIUM_LIBRARIES})
-target_link_toxcore(create_bootstrap_keys)
+target_link_sodium(create_bootstrap_keys)
 
 add_executable(create_minimal_savedata create_minimal_savedata.c)
-target_link_libraries(create_minimal_savedata PRIVATE ${LIBSODIUM_LIBRARIES})
+target_link_sodium(create_minimal_savedata)
 
 add_executable(create_savedata create_savedata.c)
-target_link_libraries(create_savedata PRIVATE ${LIBSODIUM_LIBRARIES})
+target_link_sodium(create_savedata)
 target_link_toxcore(create_savedata)
 
 add_executable(sign sign.c)
-target_link_libraries(sign PRIVATE ${LIBSODIUM_LIBRARIES} misc_tools)
+target_link_libraries(sign PRIVATE misc_tools)
+target_link_sodium(sign)
 
 add_executable(cracker_simple cracker_simple.c)
-target_link_libraries(cracker_simple ${LIBSODIUM_LIBRARIES} misc_tools)
+target_link_libraries(cracker_simple PRIVATE misc_tools)
+target_link_sodium(cracker_simple)
 
 # MSVC doesn't support OpenMP
 if(NOT MSVC)
   find_package(OpenMP)
   if(OpenMP_C_FOUND)
     add_executable(cracker cracker.c)
-    target_link_libraries(cracker PRIVATE OpenMP::OpenMP_C ${LIBSODIUM_LIBRARIES})
+    target_link_sodium(cracker)
+    target_link_libraries(cracker PRIVATE OpenMP::OpenMP_C)
   endif()
 endif()