Single Compilation Unit build.

Adds support for simple SCU build (DEV_ENABLED only).
This speeds up compilation by compiling multiple cpp files within a single translation unit.

SConstruct

@@ -55,6 +55,7 @@ _helper_module("modules.modules_builders", "modules/modules_builders.py")
 import methods
 import glsl_builders
 import gles3_builders
+import scu_builders
 from platform_methods import architectures, architecture_aliases
 
 if ARGUMENTS.get("target", "editor") == "editor":
@@ -223,6 +224,7 @@ opts.Add(
     "",
 )
 opts.Add(BoolVariable("use_precise_math_checks", "Math checks use very precise epsilon (debug option)", False))
+opts.Add(EnumVariable("scu_build", "Use single compilation unit build", "none", ("none", "dev", "all")))
 
 # Thirdparty libraries
 opts.Add(BoolVariable("builtin_certs", "Use the built-in SSL certificates bundles", True))
@@ -428,14 +430,20 @@ if env_base.debug_features:
     # to give *users* extra debugging information for their game development.
     env_base.Append(CPPDEFINES=["DEBUG_ENABLED"])
 
+
 if env_base.dev_build:
     # DEV_ENABLED enables *engine developer* code which should only be compiled for those
     # working on the engine itself.
     env_base.Append(CPPDEFINES=["DEV_ENABLED"])
+    env_base["use_scu"] = env_base["scu_build"] in ("dev", "all")
 else:
     # Disable assert() for production targets (only used in thirdparty code).
     env_base.Append(CPPDEFINES=["NDEBUG"])
 
+    # SCU builds currently use a lot of compiler memory
+    # in release builds, so disallow outside of DEV builds unless "all" is set.
+    env_base["use_scu"] = env_base["scu_build"] == "all"
+
 # SCons speed optimization controlled by the `fast_unsafe` option, which provide
 # more than 10 s speed up for incremental rebuilds.
 # Unsafe as they reduce the certainty of rebuilding all changed files, so it's
@@ -550,6 +558,10 @@ if selected_platform in platform_list:
         # LTO "auto" means we handle the preferred option in each platform detect.py.
         env["lto"] = ARGUMENTS.get("lto", "auto")
 
+    # Run SCU file generation script if in a SCU build.
+    if env["use_scu"]:
+        methods.set_scu_folders(scu_builders.generate_scu_files(env["verbose"], env_base.dev_build == False))
+
     # Must happen after the flags' definition, as configure is when most flags
     # are actually handled to change compile options, etc.
     detect.configure(env)

editor/SCsub

@@ -29,9 +29,8 @@ if env.editor_build:
     reg_exporters_inc = '#include "register_exporters.h"\n\n'
     reg_exporters = "void register_exporters() {\n"
     for e in env.platform_exporters:
-        # Glob all .cpp files in export folder
-        files = Glob("#platform/" + e + "/export/" + "*.cpp")
-        env.add_source_files(env.editor_sources, files)
+        # Add all .cpp files in export folder
+        env.add_source_files(env.editor_sources, "../platform/" + e + "/export/" + "*.cpp")
 
         reg_exporters += "\tregister_" + e + "_exporter();\n"
         reg_exporters_inc += '#include "platform/' + e + '/export/export.h"\n'

editor/editor_about.cpp

@@ -36,7 +36,7 @@
 #include "core/version.h"
 
 // The metadata key used to store and retrieve the version text to copy to the clipboard.
-static const String META_TEXT_TO_COPY = "text_to_copy";
+const String EditorAbout::META_TEXT_TO_COPY = "text_to_copy";
 
 void EditorAbout::_theme_changed() {
 	const Ref<Font> font = get_theme_font(SNAME("source"), SNAME("EditorFonts"));

editor/editor_about.h

@@ -51,6 +51,8 @@
 class EditorAbout : public AcceptDialog {
 	GDCLASS(EditorAbout, AcceptDialog);
 
+	static const String META_TEXT_TO_COPY;
+
 private:
 	void _license_tree_selected();
 	void _version_button_pressed();

editor/editor_inspector.cpp

@@ -46,14 +46,14 @@
 #include "scene/property_utils.h"
 #include "scene/resources/packed_scene.h"
 
-static bool _property_path_matches(const String &p_property_path, const String &p_filter, EditorPropertyNameProcessor::Style p_style) {
+bool EditorInspector::_property_path_matches(const String &p_property_path, const String &p_filter, EditorPropertyNameProcessor::Style p_style) {
 	if (p_property_path.findn(p_filter) != -1) {
 		return true;
 	}
 
-	const Vector<String> sections = p_property_path.split("/");
-	for (int i = 0; i < sections.size(); i++) {
-		if (p_filter.is_subsequence_ofn(EditorPropertyNameProcessor::get_singleton()->process_name(sections[i], p_style))) {
+	const Vector<String> prop_sections = p_property_path.split("/");
+	for (int i = 0; i < prop_sections.size(); i++) {
+		if (p_filter.is_subsequence_ofn(EditorPropertyNameProcessor::get_singleton()->process_name(prop_sections[i], p_style))) {
 			return true;
 		}
 	}

editor/editor_inspector.h

@@ -512,6 +512,7 @@ class EditorInspector : public ScrollContainer {
 	void _property_deleted(const String &p_path);
 	void _property_checked(const String &p_path, bool p_checked);
 	void _property_pinned(const String &p_path, bool p_pinned);
+	bool _property_path_matches(const String &p_property_path, const String &p_filter, EditorPropertyNameProcessor::Style p_style);
 
 	void _resource_selected(const String &p_path, Ref<Resource> p_resource);
 	void _property_selected(const String &p_path, int p_focusable);

editor/editor_node.cpp

@@ -6760,28 +6760,28 @@ EditorNode::EditorNode() {
 		switch (display_scale) {
 			case 0:
 				// Try applying a suitable display scale automatically.
-				editor_set_scale(EditorSettings::get_singleton()->get_auto_display_scale());
+				EditorScale::set_scale(EditorSettings::get_singleton()->get_auto_display_scale());
 				break;
 			case 1:
-				editor_set_scale(0.75);
+				EditorScale::set_scale(0.75);
 				break;
 			case 2:
-				editor_set_scale(1.0);
+				EditorScale::set_scale(1.0);
 				break;
 			case 3:
-				editor_set_scale(1.25);
+				EditorScale::set_scale(1.25);
 				break;
 			case 4:
-				editor_set_scale(1.5);
+				EditorScale::set_scale(1.5);
 				break;
 			case 5:
-				editor_set_scale(1.75);
+				EditorScale::set_scale(1.75);
 				break;
 			case 6:
-				editor_set_scale(2.0);
+				EditorScale::set_scale(2.0);
 				break;
 			default:
-				editor_set_scale(EDITOR_GET("interface/editor/custom_display_scale"));
+				EditorScale::set_scale(EDITOR_GET("interface/editor/custom_display_scale"));
 				break;
 		}
 	}

editor/editor_quick_open.cpp

@@ -34,8 +34,8 @@
 #include "editor/editor_node.h"
 #include "editor/editor_scale.h"
 
-static Rect2i prev_rect = Rect2i();
-static bool was_showed = false;
+Rect2i EditorQuickOpen::prev_rect = Rect2i();
+bool EditorQuickOpen::was_showed = false;
 
 void EditorQuickOpen::popup_dialog(const String &p_base, bool p_enable_multi, bool p_dont_clear) {
 	base_type = p_base;

editor/editor_quick_open.h

@@ -39,6 +39,9 @@
 class EditorQuickOpen : public ConfirmationDialog {
 	GDCLASS(EditorQuickOpen, ConfirmationDialog);
 
+	static Rect2i prev_rect;
+	static bool was_showed;
+
 	LineEdit *search_box = nullptr;
 	Tree *search_options = nullptr;
 	String base_type;

editor/editor_scale.cpp

@@ -30,14 +30,12 @@
 
 #include "editor_scale.h"
 
-#include "core/os/os.h"
+float EditorScale::_scale = 1.0f;
 
-static float scale = 1.0;
-
-void editor_set_scale(float p_scale) {
-	scale = p_scale;
+void EditorScale::set_scale(float p_scale) {
+	_scale = p_scale;
 }
 
-float editor_get_scale() {
-	return scale;
+float EditorScale::get_scale() {
+	return _scale;
 }

editor/editor_scale.h

@@ -31,9 +31,14 @@
 #ifndef EDITOR_SCALE_H
 #define EDITOR_SCALE_H
 
-void editor_set_scale(float p_scale);
-float editor_get_scale();
+class EditorScale {
+	static float _scale;
 
-#define EDSCALE (editor_get_scale())
+public:
+	static void set_scale(float p_scale);
+	static float get_scale();
+};
+
+#define EDSCALE (EditorScale::get_scale())
 
 #endif // EDITOR_SCALE_H

editor/plugins/text_editor.cpp

@@ -481,7 +481,7 @@ void TextEditor::_convert_case(CodeTextEditor::CaseStyle p_case) {
 	code_editor->convert_case(p_case);
 }
 
-static ScriptEditorBase *create_editor(const Ref<Resource> &p_resource) {
+ScriptEditorBase *TextEditor::create_editor(const Ref<Resource> &p_resource) {
 	if (Object::cast_to<TextFile>(*p_resource) || Object::cast_to<JSON>(*p_resource)) {
 		return memnew(TextEditor);
 	}

editor/plugins/text_editor.h

@@ -38,6 +38,8 @@
 class TextEditor : public ScriptEditorBase {
 	GDCLASS(TextEditor, ScriptEditorBase);
 
+	static ScriptEditorBase *create_editor(const Ref<Resource> &p_resource);
+
 private:
 	CodeTextEditor *code_editor = nullptr;
 

editor/plugins/visual_shader_editor_plugin.cpp

@@ -4982,7 +4982,7 @@ void VisualShaderEditor::_preview_size_changed() {
 	preview_vbox->set_custom_minimum_size(preview_window->get_size());
 }
 
-static ShaderLanguage::DataType _get_global_shader_uniform_type(const StringName &p_variable) {
+static ShaderLanguage::DataType _visual_shader_editor_get_global_shader_uniform_type(const StringName &p_variable) {
 	RS::GlobalShaderParameterType gvt = RS::get_singleton()->global_shader_parameter_get_type(p_variable);
 	return (ShaderLanguage::DataType)RS::global_shader_uniform_type_get_shader_datatype(gvt);
 }
@@ -5001,7 +5001,7 @@ void VisualShaderEditor::_update_preview() {
 	info.functions = ShaderTypes::get_singleton()->get_functions(RenderingServer::ShaderMode(visual_shader->get_mode()));
 	info.render_modes = ShaderTypes::get_singleton()->get_modes(RenderingServer::ShaderMode(visual_shader->get_mode()));
 	info.shader_types = ShaderTypes::get_singleton()->get_types();
-	info.global_shader_uniform_type_func = _get_global_shader_uniform_type;
+	info.global_shader_uniform_type_func = _visual_shader_editor_get_global_shader_uniform_type;
 
 	ShaderLanguage sl;
 

editor/project_manager.cpp

@@ -2763,28 +2763,28 @@ ProjectManager::ProjectManager() {
 		switch (display_scale) {
 			case 0:
 				// Try applying a suitable display scale automatically.
-				editor_set_scale(EditorSettings::get_singleton()->get_auto_display_scale());
+				EditorScale::set_scale(EditorSettings::get_singleton()->get_auto_display_scale());
 				break;
 			case 1:
-				editor_set_scale(0.75);
+				EditorScale::set_scale(0.75);
 				break;
 			case 2:
-				editor_set_scale(1.0);
+				EditorScale::set_scale(1.0);
 				break;
 			case 3:
-				editor_set_scale(1.25);
+				EditorScale::set_scale(1.25);
 				break;
 			case 4:
-				editor_set_scale(1.5);
+				EditorScale::set_scale(1.5);
 				break;
 			case 5:
-				editor_set_scale(1.75);
+				EditorScale::set_scale(1.75);
 				break;
 			case 6:
-				editor_set_scale(2.0);
+				EditorScale::set_scale(2.0);
 				break;
 			default:
-				editor_set_scale(EDITOR_GET("interface/editor/custom_display_scale"));
+				EditorScale::set_scale(EDITOR_GET("interface/editor/custom_display_scale"));
 				break;
 		}
 		EditorFileDialog::get_icon_func = &ProjectManager::_file_dialog_get_icon;

methods.py

@@ -6,9 +6,23 @@
 from collections import OrderedDict
 from collections.abc import Mapping
 from typing import Iterator
+from pathlib import Path
+from os.path import normpath, basename
 
+# Get the "Godot" folder name ahead of time
+base_folder_path = str(os.path.abspath(Path(__file__).parent)) + "/"
+base_folder_only = os.path.basename(os.path.normpath(base_folder_path))
+# Listing all the folders we have converted
+# for SCU in scu_builders.py
+_scu_folders = set()
 
-def add_source_files(self, sources, files):
+
+def set_scu_folders(scu_folders):
+    global _scu_folders
+    _scu_folders = scu_folders
+
+
+def add_source_files_orig(self, sources, files, allow_gen=False):
     # Convert string to list of absolute paths (including expanding wildcard)
     if isinstance(files, (str, bytes)):
         # Keep SCons project-absolute path as they are (no wildcard support)
@@ -23,7 +37,7 @@ def add_source_files(self, sources, files):
             skip_gen_cpp = "*" in files
             dir_path = self.Dir(".").abspath
             files = sorted(glob.glob(dir_path + "/" + files))
-            if skip_gen_cpp:
+            if skip_gen_cpp and not allow_gen:
                 files = [f for f in files if not f.endswith(".gen.cpp")]
 
     # Add each path as compiled Object following environment (self) configuration
@@ -35,6 +49,72 @@ def add_source_files(self, sources, files):
         sources.append(obj)
 
 
+# The section name is used for checking
+# the hash table to see whether the folder
+# is included in the SCU build.
+# It will be something like "core/math".
+def _find_scu_section_name(subdir):
+    section_path = os.path.abspath(subdir) + "/"
+
+    folders = []
+    folder = ""
+
+    for i in range(8):
+        folder = os.path.dirname(section_path)
+        folder = os.path.basename(folder)
+        if folder == base_folder_only:
+            break
+        folders += [folder]
+        section_path += "../"
+        section_path = os.path.abspath(section_path) + "/"
+
+    section_name = ""
+    for n in range(len(folders)):
+        # section_name += folders[len(folders) - n - 1] + " "
+        section_name += folders[len(folders) - n - 1]
+        if n != (len(folders) - 1):
+            section_name += "/"
+
+    return section_name
+
+
+def add_source_files_scu(self, sources, files, allow_gen=False):
+    if self["use_scu"] and isinstance(files, str):
+        if "*." not in files:
+            return False
+
+        # If the files are in a subdirectory, we want to create the scu gen
+        # files inside this subdirectory.
+        subdir = os.path.dirname(files)
+        if subdir != "":
+            subdir += "/"
+
+        section_name = _find_scu_section_name(subdir)
+        # if the section name is in the hash table?
+        # i.e. is it part of the SCU build?
+        global _scu_folders
+        if section_name not in (_scu_folders):
+            return False
+
+        if self["verbose"]:
+            print("SCU building " + section_name)
+
+        # Add all the gen.cpp files in the SCU directory
+        add_source_files_orig(self, sources, subdir + "scu/scu_*.gen.cpp", True)
+        return True
+    return False
+
+
+# Either builds the folder using the SCU system,
+# or reverts to regular build.
+def add_source_files(self, sources, files, allow_gen=False):
+    if not add_source_files_scu(self, sources, files, allow_gen):
+        # Wraps the original function when scu build is not active.
+        add_source_files_orig(self, sources, files, allow_gen)
+        return False
+    return True
+
+
 def disable_warnings(self):
     # 'self' is the environment
     if self.msvc:

scene/animation/animation_tree.cpp

@@ -941,7 +941,7 @@ void AnimationTree::_clear_playing_caches() {
 	playing_caches.clear();
 }
 
-static void _call_object(Object *p_object, const StringName &p_method, const Vector<Variant> &p_params, bool p_deferred) {
+void AnimationTree::_call_object(Object *p_object, const StringName &p_method, const Vector<Variant> &p_params, bool p_deferred) {
 	// Separate function to use alloca() more efficiently
 	const Variant **argptrs = (const Variant **)alloca(sizeof(const Variant **) * p_params.size());
 	const Variant *args = p_params.ptr();

scene/animation/animation_tree.h

@@ -194,6 +194,8 @@ class AnimationNodeEndState : public AnimationRootNode {
 class AnimationTree : public Node {
 	GDCLASS(AnimationTree, Node);
 
+	void _call_object(Object *p_object, const StringName &p_method, const Vector<Variant> &p_params, bool p_deferred);
+
 public:
 	enum AnimationProcessCallback {
 		ANIMATION_PROCESS_PHYSICS,