C#/Mono: Check assembly version when loading

Not sure if we should check revision too, but this is good enough for what we want.
This will be needed to load the correct Microsoft.Build when we switch to the nuget version.

9 files changed, 136 insertions, 72 deletions

diff --git a/modules/mono/editor/bindings_generator.cpp b/modules/mono/editor/bindings_generator.cpp
index bdf9cf965f..258b8ed3ed 100644
--- a/modules/mono/editor/bindings_generator.cpp
+++ b/modules/mono/editor/bindings_generator.cpp
@@ -1664,6 +1664,10 @@ Error BindingsGenerator::_generate_cs_method(const BindingsGenerator::TypeInterf
 		}
 
 		if (!p_imethod.is_internal) {
+			// TODO: This alone adds ~0.2 MB of bloat to the core API assembly. It would be
+			// better to generate a table in the C++ glue instead. That way the strings wouldn't
+			// add that much extra bloat as they're already used in engine code. Also, it would
+			// probably be much faster than looking up the attributes when fetching methods.
 			p_output.append(MEMBER_BEGIN "[GodotMethod(\"");
 			p_output.append(p_imethod.name);
 			p_output.append("\")]");
@@ -2139,7 +2143,7 @@ Error BindingsGenerator::_generate_glue_method(const BindingsGenerator::TypeInte
 			if (return_type->ret_as_byref_arg) {
 				p_output.append("\tif (" CS_PARAM_INSTANCE " == nullptr) { *arg_ret = ");
 				p_output.append(fail_ret);
-				p_output.append("; ERR_FAIL_MSG(\"Parameter ' arg_ret ' is null.\"); }\n");
+				p_output.append("; ERR_FAIL_MSG(\"Parameter ' " CS_PARAM_INSTANCE " ' is null.\"); }\n");
 			} else {
 				p_output.append("\tERR_FAIL_NULL_V(" CS_PARAM_INSTANCE ", ");
 				p_output.append(fail_ret);
@@ -2390,6 +2394,11 @@ bool BindingsGenerator::_populate_object_type_interfaces() {
 			if (property.usage & PROPERTY_USAGE_GROUP || property.usage & PROPERTY_USAGE_SUBGROUP || property.usage & PROPERTY_USAGE_CATEGORY)
 				continue;
 
+			if (property.name.find("/") >= 0) {
+				// Ignore properties with '/' (slash) in the name. These are only meant for use in the inspector.
+				continue;
+			}
+
 			PropertyInterface iprop;
 			iprop.cname = property.name;
 			iprop.setter = ClassDB::get_property_setter(type_cname, iprop.cname);
@@ -2402,7 +2411,7 @@ bool BindingsGenerator::_populate_object_type_interfaces() {
 
 			bool valid = false;
 			iprop.index = ClassDB::get_property_index(type_cname, iprop.cname, &valid);
-			ERR_FAIL_COND_V(!valid, false);
+			ERR_FAIL_COND_V_MSG(!valid, false, "Invalid property: '" + itype.name + "." + String(iprop.cname) + "'.");
 
 			iprop.proxy_name = escape_csharp_keyword(snake_to_pascal_case(iprop.cname));
 
@@ -2414,8 +2423,6 @@ bool BindingsGenerator::_populate_object_type_interfaces() {
 				iprop.proxy_name += "_";
 			}
 
-			iprop.proxy_name = iprop.proxy_name.replace("/", "__"); // Some members have a slash...
-
 			iprop.prop_doc = nullptr;
 
 			for (int i = 0; i < itype.class_doc->properties.size(); i++) {
diff --git a/modules/mono/editor/godotsharp_export.cpp b/modules/mono/editor/godotsharp_export.cpp
index 4126da16be..d6a271f1d9 100644
--- a/modules/mono/editor/godotsharp_export.cpp
+++ b/modules/mono/editor/godotsharp_export.cpp
@@ -32,68 +32,70 @@
 
 #include <mono/metadata/image.h>
 
+#include "core/io/file_access_pack.h"
 #include "core/os/os.h"
+#include "core/project_settings.h"
 
 #include "../mono_gd/gd_mono.h"
 #include "../mono_gd/gd_mono_assembly.h"
 #include "../mono_gd/gd_mono_cache.h"
+#include "../utils/macros.h"
 
 namespace GodotSharpExport {
 
-String get_assemblyref_name(MonoImage *p_image, int index) {
+struct AssemblyRefInfo {
+	String name;
+	uint16_t major;
+	uint16_t minor;
+	uint16_t build;
+	uint16_t revision;
+};
+
+AssemblyRefInfo get_assemblyref_name(MonoImage *p_image, int index) {
 	const MonoTableInfo *table_info = mono_image_get_table_info(p_image, MONO_TABLE_ASSEMBLYREF);
 
 	uint32_t cols[MONO_ASSEMBLYREF_SIZE];
 
 	mono_metadata_decode_row(table_info, index, cols, MONO_ASSEMBLYREF_SIZE);
 
-	return String::utf8(mono_metadata_string_heap(p_image, cols[MONO_ASSEMBLYREF_NAME]));
+	return {
+		String::utf8(mono_metadata_string_heap(p_image, cols[MONO_ASSEMBLYREF_NAME])),
+		(uint16_t)cols[MONO_ASSEMBLYREF_MAJOR_VERSION],
+		(uint16_t)cols[MONO_ASSEMBLYREF_MINOR_VERSION],
+		(uint16_t)cols[MONO_ASSEMBLYREF_BUILD_NUMBER],
+		(uint16_t)cols[MONO_ASSEMBLYREF_REV_NUMBER]
+	};
 }
 
 Error get_assembly_dependencies(GDMonoAssembly *p_assembly, const Vector<String> &p_search_dirs, Dictionary &r_assembly_dependencies) {
 	MonoImage *image = p_assembly->get_image();
 
 	for (int i = 0; i < mono_image_get_table_rows(image, MONO_TABLE_ASSEMBLYREF); i++) {
-		String ref_name = get_assemblyref_name(image, i);
+		AssemblyRefInfo ref_info = get_assemblyref_name(image, i);
+
+		const String &ref_name = ref_info.name;
 
 		if (r_assembly_dependencies.has(ref_name))
 			continue;
 
-		GDMonoAssembly *ref_assembly = nullptr;
-		String path;
-		bool has_extension = ref_name.ends_with(".dll") || ref_name.ends_with(".exe");
-
-		for (int j = 0; j < p_search_dirs.size(); j++) {
-			const String &search_dir = p_search_dirs[j];
-
-			if (has_extension) {
-				path = search_dir.plus_file(ref_name);
-				if (FileAccess::exists(path)) {
-					GDMono::get_singleton()->load_assembly_from(ref_name.get_basename(), path, &ref_assembly, true);
-					if (ref_assembly != nullptr)
-						break;
-				}
-			} else {
-				path = search_dir.plus_file(ref_name + ".dll");
-				if (FileAccess::exists(path)) {
-					GDMono::get_singleton()->load_assembly_from(ref_name, path, &ref_assembly, true);
-					if (ref_assembly != nullptr)
-						break;
-				}
-
-				path = search_dir.plus_file(ref_name + ".exe");
-				if (FileAccess::exists(path)) {
-					GDMono::get_singleton()->load_assembly_from(ref_name, path, &ref_assembly, true);
-					if (ref_assembly != nullptr)
-						break;
-				}
-			}
-		}
+		GDMonoAssembly *ref_assembly = NULL;
+
+		{
+			MonoAssemblyName *ref_aname = mono_assembly_name_new("A"); // We can't allocate an empty MonoAssemblyName, hence "A"
+			CRASH_COND(ref_aname == nullptr);
+			SCOPE_EXIT {
+				mono_assembly_name_free(ref_aname);
+				mono_free(ref_aname);
+			};
 
-		ERR_FAIL_COND_V_MSG(!ref_assembly, ERR_CANT_RESOLVE, "Cannot load assembly (refonly): '" + ref_name + "'.");
+			mono_assembly_get_assemblyref(image, i, ref_aname);
 
-		// Use the path we got from the search. Don't try to get the path from the loaded assembly as we can't trust it will be from the selected BCL dir.
-		r_assembly_dependencies[ref_name] = path;
+			if (!GDMono::get_singleton()->load_assembly(ref_name, ref_aname, &ref_assembly, /* refonly: */ true, p_search_dirs)) {
+				ERR_FAIL_V_MSG(ERR_CANT_RESOLVE, "Cannot load assembly (refonly): '" + ref_name + "'.");
+			}
+
+			r_assembly_dependencies[ref_name] = ref_assembly->get_path();
+		}
 
 		Error err = get_assembly_dependencies(ref_assembly, p_search_dirs, r_assembly_dependencies);
 		ERR_FAIL_COND_V_MSG(err != OK, err, "Cannot load one of the dependencies for the assembly: '" + ref_name + "'.");
@@ -113,6 +115,11 @@ Error get_exported_assembly_dependencies(const Dictionary &p_initial_assemblies,
 	Vector<String> search_dirs;
 	GDMonoAssembly::fill_search_dirs(search_dirs, p_build_config, p_custom_bcl_dir);
 
+	if (p_custom_bcl_dir.length()) {
+		// Only one mscorlib can be loaded. We need this workaround to make sure we get it from the right BCL directory.
+		r_assembly_dependencies["mscorlib"] = p_custom_bcl_dir.plus_file("mscorlib.dll").simplify_path();
+	}
+
 	for (const Variant *key = p_initial_assemblies.next(); key; key = p_initial_assemblies.next(key)) {
 		String assembly_name = *key;
 		String assembly_path = p_initial_assemblies[*key];
diff --git a/modules/mono/managed_callable.cpp b/modules/mono/managed_callable.cpp
index dfd78a8244..26347e9162 100644
--- a/modules/mono/managed_callable.cpp
+++ b/modules/mono/managed_callable.cpp
@@ -82,6 +82,7 @@ CallableCustom::CompareLessFunc ManagedCallable::get_compare_less_func() const {
 }
 
 ObjectID ManagedCallable::get_object() const {
+	// TODO: If the delegate target extends Godot.Object, use that instead!
 	return CSharpLanguage::get_singleton()->get_managed_callable_middleman()->get_instance_id();
 }
 
diff --git a/modules/mono/mono_gd/gd_mono.cpp b/modules/mono/mono_gd/gd_mono.cpp
index 3298c5da4c..a6ed2957e6 100644
--- a/modules/mono/mono_gd/gd_mono.cpp
+++ b/modules/mono/mono_gd/gd_mono.cpp
@@ -515,8 +515,8 @@ void GDMono::add_assembly(uint32_t p_domain_id, GDMonoAssembly *p_assembly) {
 
 GDMonoAssembly *GDMono::get_loaded_assembly(const String &p_name) {
 
-	if (p_name == "mscorlib")
-		return get_corlib_assembly();
+	if (p_name == "mscorlib" && corlib_assembly)
+		return corlib_assembly;
 
 	MonoDomain *domain = mono_domain_get();
 	uint32_t domain_id = domain ? mono_domain_get_id(domain) : 0;
@@ -526,7 +526,9 @@ GDMonoAssembly *GDMono::get_loaded_assembly(const String &p_name) {
 
 bool GDMono::load_assembly(const String &p_name, GDMonoAssembly **r_assembly, bool p_refonly) {
 
+#ifdef DEBUG_ENABLED
 	CRASH_COND(!r_assembly);
+#endif
 
 	MonoAssemblyName *aname = mono_assembly_name_new(p_name.utf8());
 	bool result = load_assembly(p_name, aname, r_assembly, p_refonly);
@@ -538,26 +540,27 @@ bool GDMono::load_assembly(const String &p_name, GDMonoAssembly **r_assembly, bo
 
 bool GDMono::load_assembly(const String &p_name, MonoAssemblyName *p_aname, GDMonoAssembly **r_assembly, bool p_refonly) {
 
+#ifdef DEBUG_ENABLED
 	CRASH_COND(!r_assembly);
+#endif
 
-	print_verbose("Mono: Loading assembly " + p_name + (p_refonly ? " (refonly)" : "") + "...");
-
-	MonoImageOpenStatus status = MONO_IMAGE_OK;
-	MonoAssembly *assembly = mono_assembly_load_full(p_aname, nullptr, &status, p_refonly);
+	return load_assembly(p_name, p_aname, r_assembly, p_refonly, GDMonoAssembly::get_default_search_dirs());
+}
 
-	if (!assembly)
-		return false;
+bool GDMono::load_assembly(const String &p_name, MonoAssemblyName *p_aname, GDMonoAssembly **r_assembly, bool p_refonly, const Vector<String> &p_search_dirs) {
 
-	ERR_FAIL_COND_V(status != MONO_IMAGE_OK, false);
+#ifdef DEBUG_ENABLED
+	CRASH_COND(!r_assembly);
+#endif
 
-	uint32_t domain_id = mono_domain_get_id(mono_domain_get());
+	print_verbose("Mono: Loading assembly " + p_name + (p_refonly ? " (refonly)" : "") + "...");
 
-	GDMonoAssembly **stored_assembly = assemblies[domain_id].getptr(p_name);
+	GDMonoAssembly *assembly = GDMonoAssembly::load(p_name, p_aname, p_refonly, p_search_dirs);
 
-	ERR_FAIL_COND_V(stored_assembly == nullptr, false);
-	ERR_FAIL_COND_V((*stored_assembly)->get_assembly() != assembly, false);
+	if (!assembly)
+		return false;
 
-	*r_assembly = *stored_assembly;
+	*r_assembly = assembly;
 
 	print_verbose("Mono: Assembly " + p_name + (p_refonly ? " (refonly)" : "") + " loaded from path: " + (*r_assembly)->get_path());
 
diff --git a/modules/mono/mono_gd/gd_mono.h b/modules/mono/mono_gd/gd_mono.h
index 4898833e8e..153ae891f7 100644
--- a/modules/mono/mono_gd/gd_mono.h
+++ b/modules/mono/mono_gd/gd_mono.h
@@ -241,6 +241,7 @@ 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(const String &p_name, MonoAssemblyName *p_aname, GDMonoAssembly **r_assembly, bool p_refonly, const Vector<String> &p_search_dirs);
 	bool load_assembly_from(const String &p_name, const String &p_path, GDMonoAssembly **r_assembly, bool p_refonly = false);
 
 	Error finalize_and_unload_domain(MonoDomain *p_domain);
diff --git a/modules/mono/mono_gd/gd_mono_assembly.cpp b/modules/mono/mono_gd/gd_mono_assembly.cpp
index 0f211eebc6..da2ed2a7fc 100644
--- a/modules/mono/mono_gd/gd_mono_assembly.cpp
+++ b/modules/mono/mono_gd/gd_mono_assembly.cpp
@@ -33,6 +33,7 @@
 #include <mono/metadata/mono-debug.h>
 #include <mono/metadata/tokentype.h>
 
+#include "core/io/file_access_pack.h"
 #include "core/list.h"
 #include "core/os/file_access.h"
 #include "core/os/os.h"
@@ -99,7 +100,7 @@ void GDMonoAssembly::fill_search_dirs(Vector<String> &r_search_dirs, const Strin
 // - The 'load' hook is called after the assembly has been loaded. Its job is to add the
 //   assembly to the list of loaded assemblies so that the 'search' hook can look it up.
 
-void GDMonoAssembly::assembly_load_hook(MonoAssembly *assembly, void *user_data) {
+void GDMonoAssembly::assembly_load_hook(MonoAssembly *assembly, [[maybe_unused]] void *user_data) {
 
 	String name = String::utf8(mono_assembly_name_get_name(mono_assembly_get_name(assembly)));
 
@@ -133,9 +134,7 @@ MonoAssembly *GDMonoAssembly::assembly_refonly_preload_hook(MonoAssemblyName *an
 	return GDMonoAssembly::_preload_hook(aname, assemblies_path, user_data, true);
 }
 
-MonoAssembly *GDMonoAssembly::_search_hook(MonoAssemblyName *aname, void *user_data, bool refonly) {
-
-	(void)user_data; // UNUSED
+MonoAssembly *GDMonoAssembly::_search_hook(MonoAssemblyName *aname, [[maybe_unused]] void *user_data, bool refonly) {
 
 	String name = String::utf8(mono_assembly_name_get_name(aname));
 	bool has_extension = name.ends_with(".dll") || name.ends_with(".exe");
@@ -147,15 +146,13 @@ MonoAssembly *GDMonoAssembly::_search_hook(MonoAssemblyName *aname, void *user_d
 	return nullptr;
 }
 
-MonoAssembly *GDMonoAssembly::_preload_hook(MonoAssemblyName *aname, char **, void *user_data, bool refonly) {
-
-	(void)user_data; // UNUSED
+MonoAssembly *GDMonoAssembly::_preload_hook(MonoAssemblyName *aname, char **, [[maybe_unused]] void *user_data, bool refonly) {
 
 	String name = String::utf8(mono_assembly_name_get_name(aname));
-	return _load_assembly_search(name, search_dirs, refonly);
+	return _load_assembly_search(name, aname, refonly, search_dirs);
 }
 
-MonoAssembly *GDMonoAssembly::_load_assembly_search(const String &p_name, const Vector<String> &p_search_dirs, bool p_refonly) {
+MonoAssembly *GDMonoAssembly::_load_assembly_search(const String &p_name, MonoAssemblyName *p_aname, bool p_refonly, const Vector<String> &p_search_dirs) {
 
 	MonoAssembly *res = nullptr;
 	String path;
@@ -168,21 +165,21 @@ MonoAssembly *GDMonoAssembly::_load_assembly_search(const String &p_name, const
 		if (has_extension) {
 			path = search_dir.plus_file(p_name);
 			if (FileAccess::exists(path)) {
-				res = _real_load_assembly_from(path, p_refonly);
+				res = _real_load_assembly_from(path, p_refonly, p_aname);
 				if (res != nullptr)
 					return res;
 			}
 		} else {
 			path = search_dir.plus_file(p_name + ".dll");
 			if (FileAccess::exists(path)) {
-				res = _real_load_assembly_from(path, p_refonly);
+				res = _real_load_assembly_from(path, p_refonly, p_aname);
 				if (res != nullptr)
 					return res;
 			}
 
 			path = search_dir.plus_file(p_name + ".exe");
 			if (FileAccess::exists(path)) {
-				res = _real_load_assembly_from(path, p_refonly);
+				res = _real_load_assembly_from(path, p_refonly, p_aname);
 				if (res != nullptr)
 					return res;
 			}
@@ -230,7 +227,7 @@ void GDMonoAssembly::initialize() {
 	mono_install_assembly_load_hook(&assembly_load_hook, nullptr);
 }
 
-MonoAssembly *GDMonoAssembly::_real_load_assembly_from(const String &p_path, bool p_refonly) {
+MonoAssembly *GDMonoAssembly::_real_load_assembly_from(const String &p_path, bool p_refonly, MonoAssemblyName *p_aname) {
 
 	Vector<uint8_t> data = FileAccess::get_file_as_array(p_path);
 	ERR_FAIL_COND_V_MSG(data.empty(), nullptr, "Could read the assembly in the specified location");
@@ -255,7 +252,33 @@ MonoAssembly *GDMonoAssembly::_real_load_assembly_from(const String &p_path, boo
 			true, &status, p_refonly,
 			image_filename.utf8());
 
-	ERR_FAIL_COND_V_MSG(status != MONO_IMAGE_OK || !image, nullptr, "Failed to open assembly image from the loaded data");
+	ERR_FAIL_COND_V_MSG(status != MONO_IMAGE_OK || !image, nullptr, "Failed to open assembly image from memory: '" + p_path + "'.");
+
+	if (p_aname != nullptr) {
+		// Check assembly version
+		const MonoTableInfo *table = mono_image_get_table_info(image, MONO_TABLE_ASSEMBLY);
+
+		ERR_FAIL_NULL_V(table, nullptr);
+
+		if (mono_table_info_get_rows(table)) {
+			uint32_t cols[MONO_ASSEMBLY_SIZE];
+			mono_metadata_decode_row(table, 0, cols, MONO_ASSEMBLY_SIZE);
+
+			// Not sure about .NET's policy. We will only ensure major and minor are equal, and ignore build and revision.
+			uint16_t major = cols[MONO_ASSEMBLY_MAJOR_VERSION];
+			uint16_t minor = cols[MONO_ASSEMBLY_MINOR_VERSION];
+
+			uint16_t required_minor;
+			uint16_t required_major = mono_assembly_name_get_version(p_aname, &required_minor, nullptr, nullptr);
+
+			if (required_major != 0) {
+				if (major != required_major && minor != required_minor) {
+					mono_image_close(image);
+					return nullptr;
+				}
+			}
+		}
+	}
 
 #ifdef DEBUG_ENABLED
 	Vector<uint8_t> pdb_data;
@@ -425,6 +448,26 @@ GDMonoClass *GDMonoAssembly::get_object_derived_class(const StringName &p_class)
 	return match;
 }
 
+GDMonoAssembly *GDMonoAssembly::load(const String &p_name, MonoAssemblyName *p_aname, bool p_refonly, const Vector<String> &p_search_dirs) {
+
+	if (GDMono::get_singleton()->get_corlib_assembly() && (p_name == "mscorlib" || p_name == "mscorlib.dll"))
+		return GDMono::get_singleton()->get_corlib_assembly();
+
+	// We need to manually call the search hook in this case, as it won't be called in the next step
+	MonoAssembly *assembly = mono_assembly_invoke_search_hook(p_aname);
+
+	if (!assembly) {
+		assembly = _load_assembly_search(p_name, p_aname, p_refonly, p_search_dirs);
+		ERR_FAIL_NULL_V(assembly, nullptr);
+	}
+
+	GDMonoAssembly *loaded_asm = GDMono::get_singleton()->get_loaded_assembly(p_name);
+	ERR_FAIL_NULL_V_MSG(loaded_asm, nullptr, "Loaded assembly missing from table. Did we not receive the load hook?");
+	ERR_FAIL_COND_V(loaded_asm->get_assembly() != assembly, nullptr);
+
+	return loaded_asm;
+}
+
 GDMonoAssembly *GDMonoAssembly::load_from(const String &p_name, const String &p_path, bool p_refonly) {
 
 	if (p_name == "mscorlib" || p_name == "mscorlib.dll")
diff --git a/modules/mono/mono_gd/gd_mono_assembly.h b/modules/mono/mono_gd/gd_mono_assembly.h
index 43c8225b74..7fc1817993 100644
--- a/modules/mono/mono_gd/gd_mono_assembly.h
+++ b/modules/mono/mono_gd/gd_mono_assembly.h
@@ -93,8 +93,8 @@ class GDMonoAssembly {
 	static MonoAssembly *_search_hook(MonoAssemblyName *aname, void *user_data, bool refonly);
 	static MonoAssembly *_preload_hook(MonoAssemblyName *aname, char **assemblies_path, void *user_data, bool refonly);
 
-	static MonoAssembly *_real_load_assembly_from(const String &p_path, bool p_refonly);
-	static MonoAssembly *_load_assembly_search(const String &p_name, const Vector<String> &p_search_dirs, bool p_refonly);
+	static MonoAssembly *_real_load_assembly_from(const String &p_path, bool p_refonly, MonoAssemblyName *p_aname = nullptr);
+	static MonoAssembly *_load_assembly_search(const String &p_name, MonoAssemblyName *p_aname, bool p_refonly, const Vector<String> &p_search_dirs);
 
 	friend class GDMono;
 	static void initialize();
@@ -120,7 +120,9 @@ public:
 	static String find_assembly(const String &p_name);
 
 	static void fill_search_dirs(Vector<String> &r_search_dirs, const String &p_custom_config = String(), const String &p_custom_bcl_dir = String());
+	static const Vector<String> &get_default_search_dirs() { return search_dirs; }
 
+	static GDMonoAssembly *load(const String &p_name, MonoAssemblyName *p_aname, bool p_refonly, const Vector<String> &p_search_dirs);
 	static GDMonoAssembly *load_from(const String &p_name, const String &p_path, bool p_refonly);
 
 	GDMonoAssembly(const String &p_name, MonoImage *p_image, MonoAssembly *p_assembly);
diff --git a/modules/mono/mono_gd/gd_mono_log.cpp b/modules/mono/mono_gd/gd_mono_log.cpp
index ca16c2b76a..b56350ae1b 100644
--- a/modules/mono/mono_gd/gd_mono_log.cpp
+++ b/modules/mono/mono_gd/gd_mono_log.cpp
@@ -175,7 +175,7 @@ void GDMonoLog::initialize() {
 	log_level_id = get_log_level_id(log_level.get_data());
 
 	if (log_file) {
-		OS::get_singleton()->print("Mono: Logfile is: %s\n", log_file_path.utf8().get_data());
+		OS::get_singleton()->print("Mono: Log file is: '%s'\n", log_file_path.utf8().get_data());
 		mono_trace_set_log_handler(mono_log_callback, this);
 	} else {
 		OS::get_singleton()->printerr("Mono: No log file, using default log handler\n");
diff --git a/modules/mono/utils/macros.h b/modules/mono/utils/macros.h
index 8650d6cc09..dc542477f5 100644
--- a/modules/mono/utils/macros.h
+++ b/modules/mono/utils/macros.h
@@ -68,6 +68,6 @@ public:
 } // namespace gdmono
 
 #define SCOPE_EXIT \
-	auto GD_UNIQUE_NAME(gd_scope_exit) = gdmono::ScopeExitAux() + [=]()
+	auto GD_UNIQUE_NAME(gd_scope_exit) = gdmono::ScopeExitAux() + [=]() -> void
 
 #endif // UTIL_MACROS_H