Mono: Editor and export template dependencies and fixes

- Bundle editor dependencies:
    - 'GodotSharp': Root data directory for the editor
        - 'Tools': Editor dependencies. Only GodotSharp.dll for now.
        - 'Api': Prebuilt GodotSharp and GodotSharpEditor API assemblies.
        - 'Mono': Mono files to bundle with the editor.
            - 'bin': (Optional, not used for now) Mono bin directory.
            - 'etc': Mono configuration files.
            - 'lib': Mono dependency shared libraries.
            - 'lib/mono/4.5': Framework assemblies.
    - Added build option to copy the required files from the mono installation to 'GodotSharp/Mono'. Enable with 'copy_mono_root=yes'. Disabled by default.

- Export template dependencies:
    - 'data_AppName'/'data_Godot':
        - 'Mono': Mono files to bundle with the game.
            - 'etc': Mono configuration files.
            - 'lib': Mono dependency shared libraries.
    - The data directory is generated when compiling and must be bundled with the export templates. In the case of OSX, the data directory must be placed inside the 'osx.zip' export template.
    - In OSX, alternative location for directories (needed for app bundles) are:
        - 'data_AppName/Mono/etc' --> '../Resources/GodotSharp/Mono/etc'
        - 'data_AppName/Mono/lib' --> '../Frameworks/GodotSharp/Mono/lib'

- The editor can bundle prebuilt API assemblies.
    - Generate them with a tools build by running: `--generate-cs-core-api <GodotSharp_OutputDir> --generate-cs-editor-api <GodotSharpEditor_OutputDir> <GodotSharp_OutputDir>/bin/Release/GodotSharp.dll` (This command will be simplified in the future and both projects will be in the same solution)
    - Build the solutions and copy the output files to '#bin/GodotSharp/Api'.
- Fixed API assembly being added twice during the export process.

4 files changed, 158 insertions, 128 deletions

diff --git a/modules/mono/mono_gd/gd_mono.cpp b/modules/mono/mono_gd/gd_mono.cpp
index 9311aa3930..bf5455de16 100644
--- a/modules/mono/mono_gd/gd_mono.cpp
+++ b/modules/mono/mono_gd/gd_mono.cpp
@@ -162,50 +162,63 @@ void GDMono::initialize() {
 	mono_trace_set_printerr_handler(gdmono_MonoPrintCallback);
 #endif
 
+	String assembly_rootdir;
+	String config_dir;
+
+#ifdef TOOLS_ENABLED
 #ifdef WINDOWS_ENABLED
 	mono_reg_info = MonoRegUtils::find_mono();
 
-	CharString assembly_dir;
-	CharString config_dir;
-
 	if (mono_reg_info.assembly_dir.length() && DirAccess::exists(mono_reg_info.assembly_dir)) {
-		assembly_dir = mono_reg_info.assembly_dir.utf8();
+		assembly_rootdir = mono_reg_info.assembly_dir;
 	}
 
 	if (mono_reg_info.config_dir.length() && DirAccess::exists(mono_reg_info.config_dir)) {
-		config_dir = mono_reg_info.config_dir.utf8();
+		config_dir = mono_reg_info.config_dir;
 	}
-
-	mono_set_dirs(assembly_dir.length() ? assembly_dir.get_data() : NULL,
-			config_dir.length() ? config_dir.get_data() : NULL);
 #elif OSX_ENABLED
-	mono_set_dirs(NULL, NULL);
-
-	{
-		const char *assembly_rootdir = mono_assembly_getrootdir();
-		const char *config_dir = mono_get_config_dir();
-
-		if (!assembly_rootdir || !config_dir || !DirAccess::exists(assembly_rootdir) || !DirAccess::exists(config_dir)) {
-			Vector<const char *> locations;
-			locations.push_back("/Library/Frameworks/Mono.framework/Versions/Current/");
-			locations.push_back("/usr/local/var/homebrew/linked/mono/");
-
-			for (int i = 0; i < locations.size(); i++) {
-				String hint_assembly_rootdir = path_join(locations[i], "lib");
-				String hint_mscorlib_path = path_join(hint_assembly_rootdir, "mono", "4.5", "mscorlib.dll");
-				String hint_config_dir = path_join(locations[i], "etc");
-
-				if (FileAccess::exists(hint_mscorlib_path) && DirAccess::exists(hint_config_dir)) {
-					mono_set_dirs(hint_assembly_rootdir.utf8().get_data(), hint_config_dir.utf8().get_data());
-					break;
-				}
+	const char *c_assembly_rootdir = mono_assembly_getrootdir();
+	const char *c_config_dir = mono_get_config_dir();
+
+	if (!c_assembly_rootdir || !c_config_dir || !DirAccess::exists(c_assembly_rootdir) || !DirAccess::exists(c_config_dir)) {
+		Vector<const char *> locations;
+		locations.push_back("/Library/Frameworks/Mono.framework/Versions/Current/");
+		locations.push_back("/usr/local/var/homebrew/linked/mono/");
+
+		for (int i = 0; i < locations.size(); i++) {
+			String hint_assembly_rootdir = path_join(locations[i], "lib");
+			String hint_mscorlib_path = path_join(hint_assembly_rootdir, "mono", "4.5", "mscorlib.dll");
+			String hint_config_dir = path_join(locations[i], "etc");
+
+			if (FileAccess::exists(hint_mscorlib_path) && DirAccess::exists(hint_config_dir)) {
+				need_set_mono_dirs = false;
+				assembly_rootdir = hint_assembly_rootdir;
+				config_dir = hint_config_dir;
+				break;
 			}
 		}
 	}
+#endif
+#endif // TOOLS_ENABLED
+
+	String bundled_assembly_rootdir = GodotSharpDirs::get_data_mono_lib_dir();
+	String bundled_config_dir = GodotSharpDirs::get_data_mono_etc_dir();
+
+#ifdef TOOLS_ENABLED
+	if (DirAccess::exists(bundled_assembly_rootdir) && DirAccess::exists(bundled_config_dir)) {
+		assembly_rootdir = bundled_assembly_rootdir;
+		config_dir = bundled_config_dir;
+	}
 #else
-	mono_set_dirs(NULL, NULL);
+	// These are always the directories in export templates
+	assembly_rootdir = bundled_assembly_rootdir;
+	config_dir = bundled_config_dir;
 #endif
 
+	// Leak if we call mono_set_dirs more than once
+	mono_set_dirs(assembly_rootdir.length() ? assembly_rootdir.utf8().get_data() : NULL,
+			config_dir.length() ? config_dir.utf8().get_data() : NULL);
+
 	GDMonoAssembly::initialize();
 
 #ifdef DEBUG_ENABLED
@@ -262,8 +275,11 @@ void GDMono::initialize() {
 		// Everything is fine with the api assemblies, load the project assembly
 		_load_project_assembly();
 	} else {
-		if ((core_api_assembly && (core_api_assembly_out_of_sync || !GDMonoUtils::mono_cache.godot_api_cache_updated)) ||
-				(editor_api_assembly && editor_api_assembly_out_of_sync)) {
+		if ((core_api_assembly && (core_api_assembly_out_of_sync || !GDMonoUtils::mono_cache.godot_api_cache_updated))
+#ifdef TOOLS_ENABLED
+				|| (editor_api_assembly && editor_api_assembly_out_of_sync)
+#endif
+		) {
 #ifdef TOOLS_ENABLED
 			// The assembly was successfully loaded, but the full api could not be cached.
 			// This is most likely an outdated assembly loaded because of an invalid version in the
@@ -362,24 +378,34 @@ GDMonoAssembly **GDMono::get_loaded_assembly(const String &p_name) {
 
 bool GDMono::load_assembly(const String &p_name, GDMonoAssembly **r_assembly, bool p_refonly) {
 
+	return load_assembly_from(p_name, String(), r_assembly, p_refonly);
+}
+
+bool GDMono::load_assembly(const String &p_name, MonoAssemblyName *p_aname, GDMonoAssembly **r_assembly, bool p_refonly) {
+
+	return load_assembly_from(p_name, String(), p_aname, r_assembly, p_refonly);
+}
+
+bool GDMono::load_assembly_from(const String &p_name, const String &p_basedir, GDMonoAssembly **r_assembly, bool p_refonly) {
+
 	CRASH_COND(!r_assembly);
 
 	MonoAssemblyName *aname = mono_assembly_name_new(p_name.utf8());
-	bool result = load_assembly(p_name, aname, r_assembly, p_refonly);
+	bool result = load_assembly_from(p_name, p_basedir, aname, r_assembly, p_refonly);
 	mono_assembly_name_free(aname);
 	mono_free(aname);
 
 	return result;
 }
 
-bool GDMono::load_assembly(const String &p_name, MonoAssemblyName *p_aname, GDMonoAssembly **r_assembly, bool p_refonly) {
+bool GDMono::load_assembly_from(const String &p_name, const String &p_basedir, MonoAssemblyName *p_aname, GDMonoAssembly **r_assembly, bool p_refonly) {
 
 	CRASH_COND(!r_assembly);
 
 	print_verbose("Mono: Loading assembly " + p_name + (p_refonly ? " (refonly)" : "") + "...");
 
 	MonoImageOpenStatus status = MONO_IMAGE_OK;
-	MonoAssembly *assembly = mono_assembly_load_full(p_aname, NULL, &status, p_refonly);
+	MonoAssembly *assembly = mono_assembly_load_full(p_aname, p_basedir.length() ? p_basedir.utf8().get_data() : NULL, &status, p_refonly);
 
 	if (!assembly)
 		return false;
@@ -480,12 +506,10 @@ bool GDMono::_load_editor_api_assembly() {
 	if (editor_api_assembly)
 		return true;
 
-#ifdef TOOLS_ENABLED
 	if (metadata_is_api_assembly_invalidated(APIAssembly::API_EDITOR)) {
 		print_verbose("Mono: Skipping loading of Editor API assembly because it was invalidated");
 		return false;
 	}
-#endif
 
 	bool success = load_assembly(EDITOR_API_ASSEMBLY_NAME, &editor_api_assembly);
 
@@ -772,7 +796,7 @@ Error GDMono::finalize_and_unload_domain(MonoDomain *p_domain) {
 
 	print_verbose("Mono: Unloading domain `" + domain_name + "`...");
 
-	if (mono_domain_get() != root_domain)
+	if (mono_domain_get() == p_domain)
 		mono_domain_set(root_domain, true);
 
 	mono_gc_collect(mono_gc_max_generation());
diff --git a/modules/mono/mono_gd/gd_mono.h b/modules/mono/mono_gd/gd_mono.h
index 0c5503d28e..e6ac042c1f 100644
--- a/modules/mono/mono_gd/gd_mono.h
+++ b/modules/mono/mono_gd/gd_mono.h
@@ -142,7 +142,7 @@ class GDMono {
 
 	GDMonoLog *gdmono_log;
 
-#ifdef WINDOWS_ENABLED
+#if defined(WINDOWS_ENABLED) && defined(TOOLS_ENABLED)
 	MonoRegInfo mono_reg_info;
 #endif
 
@@ -197,6 +197,9 @@ public:
 
 	bool load_assembly(const String &p_name, GDMonoAssembly **r_assembly, bool p_refonly = false);
 	bool load_assembly(const String &p_name, MonoAssemblyName *p_aname, GDMonoAssembly **r_assembly, bool p_refonly = false);
+	bool load_assembly_from(const String &p_name, const String &p_basedir, GDMonoAssembly **r_assembly, bool p_refonly = false);
+	bool load_assembly_from(const String &p_name, const String &p_basedir, MonoAssemblyName *p_aname, GDMonoAssembly **r_assembly, bool p_refonly = false);
+
 	Error finalize_and_unload_domain(MonoDomain *p_domain);
 
 	void initialize();
@@ -205,12 +208,14 @@ public:
 	~GDMono();
 };
 
-class GDMonoScopeDomain {
+namespace gdmono {
+
+class ScopeDomain {
 
 	MonoDomain *prev_domain;
 
 public:
-	GDMonoScopeDomain(MonoDomain *p_domain) {
+	ScopeDomain(MonoDomain *p_domain) {
 		MonoDomain *prev_domain = mono_domain_get();
 		if (prev_domain != p_domain) {
 			this->prev_domain = prev_domain;
@@ -220,16 +225,36 @@ public:
 		}
 	}
 
-	~GDMonoScopeDomain() {
+	~ScopeDomain() {
 		if (prev_domain)
 			mono_domain_set(prev_domain, false);
 	}
 };
 
-#define _GDMONO_SCOPE_DOMAIN_(m_mono_domain)                    \
-	GDMonoScopeDomain __gdmono__scope__domain__(m_mono_domain); \
+class ScopeExitDomainUnload {
+	MonoDomain *domain;
+
+public:
+	ScopeExitDomainUnload(MonoDomain *p_domain) :
+			domain(p_domain) {
+	}
+
+	~ScopeExitDomainUnload() {
+		if (domain)
+			GDMono::get_singleton()->finalize_and_unload_domain(domain);
+	}
+};
+
+} // namespace gdmono
+
+#define _GDMONO_SCOPE_DOMAIN_(m_mono_domain)                      \
+	gdmono::ScopeDomain __gdmono__scope__domain__(m_mono_domain); \
 	(void)__gdmono__scope__domain__;
 
+#define _GDMONO_SCOPE_EXIT_DOMAIN_UNLOAD_(m_mono_domain)                                  \
+	gdmono::ScopeExitDomainUnload __gdmono__scope__exit__domain__unload__(m_mono_domain); \
+	(void)__gdmono__scope__exit__domain__unload__;
+
 class _GodotSharp : public Object {
 	GDCLASS(_GodotSharp, Object)
 
diff --git a/modules/mono/mono_gd/gd_mono_assembly.cpp b/modules/mono/mono_gd/gd_mono_assembly.cpp
index 27ce39b6d7..1067c11e0e 100644
--- a/modules/mono/mono_gd/gd_mono_assembly.cpp
+++ b/modules/mono/mono_gd/gd_mono_assembly.cpp
@@ -46,6 +46,29 @@ bool GDMonoAssembly::in_preload = false;
 
 Vector<String> GDMonoAssembly::search_dirs;
 
+void GDMonoAssembly::fill_search_dirs(Vector<String> &r_search_dirs, const String &p_custom_config) {
+
+	const char *rootdir = mono_assembly_getrootdir();
+	if (rootdir) {
+		String framework_dir = String(rootdir).plus_file("mono").plus_file("4.5");
+		r_search_dirs.push_back(framework_dir);
+		r_search_dirs.push_back(framework_dir.plus_file("Facades"));
+	}
+
+	if (p_custom_config.length()) {
+		r_search_dirs.push_back(GodotSharpDirs::get_res_temp_assemblies_base_dir().plus_file(p_custom_config));
+	} else {
+		r_search_dirs.push_back(GodotSharpDirs::get_res_temp_assemblies_dir());
+	}
+
+	r_search_dirs.push_back(GodotSharpDirs::get_res_assemblies_dir());
+	r_search_dirs.push_back(OS::get_singleton()->get_resource_dir());
+	r_search_dirs.push_back(OS::get_singleton()->get_executable_path().get_base_dir());
+#ifdef TOOLS_ENABLED
+	r_search_dirs.push_back(GodotSharpDirs::get_data_editor_tools_dir());
+#endif
+}
+
 void GDMonoAssembly::assembly_load_hook(MonoAssembly *assembly, void *user_data) {
 
 	if (no_search)
@@ -93,35 +116,7 @@ MonoAssembly *GDMonoAssembly::_search_hook(MonoAssemblyName *aname, void *user_d
 
 	no_search = true; // Avoid the recursion madness
 
-	String path;
-	GDMonoAssembly *res = NULL;
-
-	for (int i = 0; i < search_dirs.size(); i++) {
-		const String &search_dir = search_dirs[i];
-
-		if (has_extension) {
-			path = search_dir.plus_file(name);
-			if (FileAccess::exists(path)) {
-				res = _load_assembly_from(name.get_basename(), path, refonly);
-				if (res != NULL)
-					break;
-			}
-		} else {
-			path = search_dir.plus_file(name + ".dll");
-			if (FileAccess::exists(path)) {
-				res = _load_assembly_from(name, path, refonly);
-				if (res != NULL)
-					break;
-			}
-
-			path = search_dir.plus_file(name + ".exe");
-			if (FileAccess::exists(path)) {
-				res = _load_assembly_from(name, path, refonly);
-				if (res != NULL)
-					break;
-			}
-		}
-	}
+	GDMonoAssembly *res = _load_assembly_search(name, search_dirs, refonly);
 
 	no_search = false;
 
@@ -130,31 +125,12 @@ MonoAssembly *GDMonoAssembly::_search_hook(MonoAssemblyName *aname, void *user_d
 
 static _THREAD_LOCAL_(MonoImage *) image_corlib_loading = NULL;
 
-MonoAssembly *GDMonoAssembly::_preload_hook(MonoAssemblyName *aname, char **assemblies_path, void *user_data, bool refonly) {
+MonoAssembly *GDMonoAssembly::_preload_hook(MonoAssemblyName *aname, char **, void *user_data, bool refonly) {
 
 	(void)user_data; // UNUSED
 
 	if (search_dirs.empty()) {
-		search_dirs.push_back(GodotSharpDirs::get_res_temp_assemblies_dir());
-		search_dirs.push_back(GodotSharpDirs::get_res_assemblies_dir());
-		search_dirs.push_back(OS::get_singleton()->get_resource_dir());
-		search_dirs.push_back(OS::get_singleton()->get_executable_path().get_base_dir());
-#ifdef GD_MONO_EDITOR_ASSEMBLIES_DIR
-		search_dirs.push_back(OS::get_singleton()->get_executable_path().get_base_dir().plus_file(_MKSTR(GD_MONO_EDITOR_ASSEMBLIES_DIR)).simplify_path());
-#endif
-
-		const char *rootdir = mono_assembly_getrootdir();
-		if (rootdir) {
-			search_dirs.push_back(String(rootdir).plus_file("mono").plus_file("4.5"));
-			search_dirs.push_back(String(rootdir).plus_file("mono").plus_file("4.5").plus_file("Facades"));
-		}
-
-		if (assemblies_path) {
-			while (*assemblies_path) {
-				search_dirs.push_back(*assemblies_path);
-				++assemblies_path;
-			}
-		}
+		fill_search_dirs(search_dirs);
 	}
 
 	{
@@ -188,27 +164,7 @@ MonoAssembly *GDMonoAssembly::_preload_hook(MonoAssemblyName *aname, char **asse
 		if (stored_assembly)
 			return (*stored_assembly)->get_assembly();
 
-		String path;
-
-		for (int i = 0; i < search_dirs.size(); i++) {
-			const String &search_dir = search_dirs[i];
-
-			if (has_extension) {
-				path = search_dir.plus_file(name);
-				if (FileAccess::exists(path)) {
-					res = _load_assembly_from(name.get_basename(), path, refonly);
-					if (res != NULL)
-						break;
-				}
-			} else {
-				path = search_dir.plus_file(name + ".dll");
-				if (FileAccess::exists(path)) {
-					res = _load_assembly_from(name, path, refonly);
-					if (res != NULL)
-						break;
-				}
-			}
-		}
+		res = _load_assembly_search("mscorlib.dll", search_dirs, refonly);
 	}
 
 	no_search = false;
@@ -217,6 +173,43 @@ MonoAssembly *GDMonoAssembly::_preload_hook(MonoAssemblyName *aname, char **asse
 	return res ? res->get_assembly() : NULL;
 }
 
+GDMonoAssembly *GDMonoAssembly::_load_assembly_search(const String &p_name, const Vector<String> &p_search_dirs, bool p_refonly) {
+
+	GDMonoAssembly *res = NULL;
+	String path;
+
+	bool has_extension = p_name.ends_with(".dll") || p_name.ends_with(".exe");
+
+	for (int i = 0; i < p_search_dirs.size(); i++) {
+		const String &search_dir = p_search_dirs[i];
+
+		if (has_extension) {
+			path = search_dir.plus_file(p_name);
+			if (FileAccess::exists(path)) {
+				res = _load_assembly_from(p_name.get_basename(), path, p_refonly);
+				if (res != NULL)
+					return res;
+			}
+		} else {
+			path = search_dir.plus_file(p_name + ".dll");
+			if (FileAccess::exists(path)) {
+				res = _load_assembly_from(p_name, path, p_refonly);
+				if (res != NULL)
+					return res;
+			}
+
+			path = search_dir.plus_file(p_name + ".exe");
+			if (FileAccess::exists(path)) {
+				res = _load_assembly_from(p_name, path, p_refonly);
+				if (res != NULL)
+					return res;
+			}
+		}
+	}
+
+	return NULL;
+}
+
 GDMonoAssembly *GDMonoAssembly::_load_assembly_from(const String &p_name, const String &p_path, bool p_refonly) {
 
 	GDMonoAssembly *assembly = memnew(GDMonoAssembly(p_name, p_path));
@@ -464,19 +457,6 @@ GDMonoClass *GDMonoAssembly::get_object_derived_class(const StringName &p_class)
 	return match;
 }
 
-GDMonoAssembly *GDMonoAssembly::load_from(const String &p_name, const String &p_path, bool p_refonly) {
-
-	GDMonoAssembly **loaded_asm = GDMono::get_singleton()->get_loaded_assembly(p_name);
-	if (loaded_asm)
-		return *loaded_asm;
-
-	no_search = true;
-	GDMonoAssembly *res = _load_assembly_from(p_name, p_path, p_refonly);
-	no_search = false;
-
-	return res;
-}
-
 GDMonoAssembly::GDMonoAssembly(const String &p_name, const String &p_path) {
 
 	loaded = false;
diff --git a/modules/mono/mono_gd/gd_mono_assembly.h b/modules/mono/mono_gd/gd_mono_assembly.h
index 0ba11ac412..4c9b1cb10d 100644
--- a/modules/mono/mono_gd/gd_mono_assembly.h
+++ b/modules/mono/mono_gd/gd_mono_assembly.h
@@ -102,6 +102,7 @@ class GDMonoAssembly {
 	static MonoAssembly *_preload_hook(MonoAssemblyName *aname, char **assemblies_path, void *user_data, bool refonly);
 
 	static GDMonoAssembly *_load_assembly_from(const String &p_name, const String &p_path, bool p_refonly);
+	static GDMonoAssembly *_load_assembly_search(const String &p_name, const Vector<String> &p_search_dirs, bool p_refonly);
 	static void _wrap_mono_assembly(MonoAssembly *assembly);
 
 	friend class GDMono;
@@ -125,7 +126,7 @@ public:
 
 	GDMonoClass *get_object_derived_class(const StringName &p_class);
 
-	static GDMonoAssembly *load_from(const String &p_name, const String &p_path, bool p_refonly);
+	static void fill_search_dirs(Vector<String> &r_search_dirs, const String &p_custom_config = String());
 
 	GDMonoAssembly(const String &p_name, const String &p_path = String());
 	~GDMonoAssembly();