Hide unused symbols in unix libraries

manually added android ndk r23

.github/actions/compile_gdextension/action.yml

@@ -68,6 +68,7 @@ runs:
       run: |
         echo "::group::🛠️ GDExtesion Compilation 🛠️"
         cd godot-cpp
+        git apply --ignore-space-change --ignore-whitespace ../patches/visibilty_hidden.patch
         git apply --ignore-space-change --ignore-whitespace ../patches/godot_cpp_exclude_unused_classes.patch
         git apply --ignore-space-change --ignore-whitespace ../patches/unity_build.patch
         cd ..

.github/workflows/gdextension_build.yml

@@ -122,15 +122,37 @@ jobs:
           lfs: true
           submodules: recursive
 
+      - name: Install Android NDK r23
+        uses: nttld/setup-ndk@v1.4.1
+        id: setup-ndk
+        with:
+          ndk-version: r23
+          add-to-path: true
+          local-cache: true
+
+      # TODO revisit after some updates of nttld/setup-ndk
+      - name: Restore Android Symlinks
+        run: |
+          directory="${{ steps.setup-ndk.outputs.ndk-path }}/toolchains/llvm/prebuilt/linux-x86_64/bin"
+
+          find "$directory" -type l | while read link; do
+              current_target=$(readlink "$link")
+              new_target="$directory/$(basename "$current_target")"
+              ln -sf "$new_target" "$link"
+              echo "Changed $(basename "$link") from $current_target to $new_target"
+          done
+
       - name: Compile GDExtension
         uses: ./.github/actions/compile_gdextension
+        env:
+          ANDROID_NDK_ROOT: ${{ steps.setup-ndk.outputs.ndk-path }}
         with:
           platform: android
           target: ${{matrix.target}}
           arch: ${{matrix.arch}}
           output_libs_path: ${{env.OUTPUT_LIBS_PATH}}
           artifact: android
-          additional: lto=yes
+          additional: lto=yes ANDROID_HOME=""
 
   # ============================================
 

dev_build_godot_cpp.bat

@@ -2,6 +2,7 @@ cd godot-cpp
 ::set api=custom_api_file="../api.json"
 set api= 
 
+git apply --ignore-space-change --ignore-whitespace ../patches/visibilty_hidden.patch
 git apply --ignore-space-change --ignore-whitespace ../patches/godot_cpp_exclude_unused_classes.patch
 git apply --ignore-space-change --ignore-whitespace ../patches/unity_build.patch
 ::git apply --ignore-space-change --ignore-whitespace ../patches/debug_string.patch

patches/visibilty_hidden.patch

@@ -0,0 +1,35 @@
+diff --git a/tools/godotcpp.py b/tools/godotcpp.py
+index efe632a..46d64fb 100644
+--- a/tools/godotcpp.py
++++ b/tools/godotcpp.py
+@@ -183,6 +183,15 @@ def options(opts, env):
+         )
+     )
+
++    opts.Add(
++        EnumVariable(
++            key="symbols_visibility",
++            help="Symbols visibility on GNU platforms. Use 'auto' to apply the default values.",
++            default=env.get("symbols_visibility", "hidden"),
++            allowed_values=["auto", "visible", "hidden"],
++        )
++    )
++
+     # Add platform options
+     for pl in platforms:
+         tool = Tool(pl, toolpath=["tools"])
+@@ -258,6 +267,14 @@ def generate(env):
+     elif env.get("is_msvc", False):
+         env.Append(CXXFLAGS=["/EHsc"])
+
++    if not env.get("is_msvc", False):
++        if env["symbols_visibility"] == "visible":
++            env.Append(CCFLAGS=["-fvisibility=default"])
++            env.Append(LINKFLAGS=["-fvisibility=default"])
++        elif env["symbols_visibility"] == "hidden":
++            env.Append(CCFLAGS=["-fvisibility=hidden"])
++            env.Append(LINKFLAGS=["-fvisibility=hidden"])
++
+     # Require C++17
+     if env.get("is_msvc", False):
+         env.Append(CXXFLAGS=["/std:c++17"])