From 834cbe8cef88fd2177c71480c82ab5802c725ca2 Mon Sep 17 00:00:00 2001
From: Relintai <relintai@protonmail.com>
Date: Tue, 11 Jul 2023 16:07:36 +0200
Subject: [PATCH] Ported:  Single Compilation Unit build. Adds support for
 simple SCU build. This speeds up compilation by compiling multiple cpp files
 within a single translation unit. - lawnjelly
 https://github.com/godotengine/godot/commit/43e181a00ab39671a3bb0b2d0302e25313f18aef

---
 SConstruct                                    |   6 +
 core/math/color_names.inc                     |   7 +
 core/object/make_binders.py                   |   6 +-
 drivers/gles2/rasterizer_scene_gles2.cpp      |   4 +-
 drivers/gles2/rasterizer_scene_gles2.h        |   2 +
 drivers/gles2/shader_gles2.cpp                |   2 +-
 drivers/gles2/shader_gles2.h                  |   2 +
 editor/editor_about.cpp                       |   2 +-
 editor/editor_about.h                         |   2 +
 .../editor_script_text_editor.cpp             |   2 +-
 .../editor_script_text_editor.h               |   2 +
 .../editor_code_editor/editor_text_editor.cpp |   2 +-
 .../editor_code_editor/editor_text_editor.h   |   2 +
 main/tests/test_string.cpp.old                |   2 +
 main/tests/test_theme.cpp                     |   2 +
 methods.py                                    |  83 ++-
 scene/gui/box_container.cpp                   |   6 -
 scene/gui/box_container.h                     |   6 +
 scene/gui/line_edit.cpp                       |   2 +-
 scene/gui/line_edit.h                         |   1 +
 scu_builders.py                               | 578 ++++++++++++++++++
 servers/physics/joints/hinge_joint_sw.cpp     |   4 +-
 servers/physics/joints/hinge_joint_sw.h       |   3 +
 servers/physics/joints/slider_joint_sw.cpp    |   2 +-
 servers/physics/joints/slider_joint_sw.h      |   3 +
 25 files changed, 713 insertions(+), 20 deletions(-)
 create mode 100644 scu_builders.py

diff --git a/SConstruct b/SConstruct
index 1dcc4b6b6..b4dc25f62 100644
--- a/SConstruct
+++ b/SConstruct
@@ -14,6 +14,7 @@ from collections import OrderedDict
 # Local
 import methods
 import gles_builders
+import scu_builders
 from platform_methods import run_in_subprocess
 
 # scan possible build platforms
@@ -159,6 +160,7 @@ opts.Add(BoolVariable("disable_advanced_gui", "Disable advanced GUI nodes and be
 opts.Add(BoolVariable("no_editor_splash", "Don't use the custom splash screen for the editor", True))
 opts.Add("system_certs_path", "Use this path as SSL certificates default for editor (for package maintainers)", "")
 opts.Add(BoolVariable("use_precise_math_checks", "Math checks use very precise epsilon (debug option)", False))
+opts.Add(BoolVariable("scu_build", "Use single compilation unit build", False))
 opts.Add(
     EnumVariable(
         "rids",
@@ -428,6 +430,10 @@ if selected_platform in platform_list:
                 "for an optimized template with debug features)."
             )
 
+    # Run SCU file generation script if in a SCU build.
+    if env["scu_build"]:
+        methods.set_scu_folders(scu_builders.generate_scu_files(env["verbose"], env_base["target"] != "debug"))
+
     # Must happen after the flags' definition, as configure is when most flags
     # are actually handled to change compile options, etc.
     detect.configure(env)
diff --git a/core/math/color_names.inc b/core/math/color_names.inc
index bee1ed5c8..d6ca0c063 100644
--- a/core/math/color_names.inc
+++ b/core/math/color_names.inc
@@ -1,4 +1,9 @@
+
+#ifndef COLOR_NAMES_INC_H
+#define COLOR_NAMES_INC_H
+
 // Names from https://en.wikipedia.org/wiki/X11_color_names
+
 #include "core/containers/rb_map.h"
 
 static RBMap<String, Color> _named_colors;
@@ -153,3 +158,5 @@ static void _populate_named_colors() {
 	_named_colors.insert("yellow", Color(1.00, 1.00, 0.00));
 	_named_colors.insert("yellowgreen", Color(0.60, 0.80, 0.20));
 }
+
+#endif
diff --git a/core/object/make_binders.py b/core/object/make_binders.py
index d6ccdf9f7..bf211f2b7 100644
--- a/core/object/make_binders.py
+++ b/core/object/make_binders.py
@@ -343,8 +343,8 @@ def run(target, source, env):
 
     versions = 13
     versions_ext = 6
-    text = ""
-    text_ext = ""
+    text = "#ifndef METHOD_BIND_GEN_INC_H\n#define METHOD_BIND_GEN_INC_H\n"
+    text_ext = "#ifndef METHOD_BIND_EXT_GEN_INC_H\n#define METHOD_BIND_EXT_GEN_INC_H\n"
     text_free_func = "#ifndef METHOD_BIND_FREE_FUNC_H\n#define METHOD_BIND_FREE_FUNC_H\n"
     text_free_func += "\n//including this header file allows method binding to use free functions\n"
     text_free_func += (
@@ -372,6 +372,8 @@ def run(target, source, env):
         text_free_func += make_version(template_typed_free_func, i, versions, True, False)
         text_free_func += make_version(template_typed_free_func, i, versions, True, True)
 
+    text += "#endif"
+    text_ext += "#endif"
     text_free_func += "#endif"
 
     with open(target[0], "w") as f:
diff --git a/drivers/gles2/rasterizer_scene_gles2.cpp b/drivers/gles2/rasterizer_scene_gles2.cpp
index bc35fea99..3aed4b799 100644
--- a/drivers/gles2/rasterizer_scene_gles2.cpp
+++ b/drivers/gles2/rasterizer_scene_gles2.cpp
@@ -52,7 +52,7 @@
 #endif
 #endif
 
-static const GLenum _cube_side_enum[6] = {
+const GLenum RasterizerSceneGLES2::_cube_side_enum[6] = {
 
 	GL_TEXTURE_CUBE_MAP_NEGATIVE_X,
 	GL_TEXTURE_CUBE_MAP_POSITIVE_X,
@@ -1304,7 +1304,7 @@ void RasterizerSceneGLES2::_fill_render_list(InstanceBase **p_cull_result, int p
 	}
 }
 
-static const GLenum gl_primitive[] = {
+const GLenum RasterizerSceneGLES2::gl_primitive[] = {
 	GL_POINTS,
 	GL_LINES,
 	GL_LINE_STRIP,
diff --git a/drivers/gles2/rasterizer_scene_gles2.h b/drivers/gles2/rasterizer_scene_gles2.h
index 600044369..0ac2e84da 100644
--- a/drivers/gles2/rasterizer_scene_gles2.h
+++ b/drivers/gles2/rasterizer_scene_gles2.h
@@ -89,6 +89,8 @@ public:
 
 private:
 	uint32_t _light_counter;
+	static const GLenum gl_primitive[];
+	static const GLenum _cube_side_enum[6];
 
 public:
 	RasterizerStorageGLES2 *storage;
diff --git a/drivers/gles2/shader_gles2.cpp b/drivers/gles2/shader_gles2.cpp
index 16da66d7c..665405757 100644
--- a/drivers/gles2/shader_gles2.cpp
+++ b/drivers/gles2/shader_gles2.cpp
@@ -126,7 +126,7 @@ static void _display_error_with_code(const String &p_error, const Vector<const c
 	ERR_PRINT(p_error);
 }
 
-static String _mkid(const String &p_id) {
+String ShaderGLES2::_mkid(const String &p_id) {
 	String id = "m_" + p_id;
 	return id.replace("__", "_dus_"); //doubleunderscore is reserved in glsl
 }
diff --git a/drivers/gles2/shader_gles2.h b/drivers/gles2/shader_gles2.h
index 115c320e0..9783fb00c 100644
--- a/drivers/gles2/shader_gles2.h
+++ b/drivers/gles2/shader_gles2.h
@@ -50,6 +50,8 @@
 class RasterizerStorageGLES2;
 
 class ShaderGLES2 {
+	static String _mkid(const String &p_id);
+	
 protected:
 	struct Enum {
 		uint64_t mask;
diff --git a/editor/editor_about.cpp b/editor/editor_about.cpp
index 492591b32..435751052 100644
--- a/editor/editor_about.cpp
+++ b/editor/editor_about.cpp
@@ -59,7 +59,7 @@
 #include "scene/resources/texture.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::_notification(int p_what) {
 	switch (p_what) {
diff --git a/editor/editor_about.h b/editor/editor_about.h
index 3e12ff152..216575469 100644
--- a/editor/editor_about.h
+++ b/editor/editor_about.h
@@ -50,6 +50,8 @@ class EditorAbout : public AcceptDialog {
 	GDCLASS(EditorAbout, AcceptDialog);
 
 private:
+	static const String META_TEXT_TO_COPY;
+
 	void _license_tree_selected();
 	void _version_button_pressed();
 	ScrollContainer *_populate_list(const String &p_name, const List<String> &p_sections, const char *const *const p_src[], const int p_flag_single_column = 0);
diff --git a/editor_modules/editor_code_editor/editor_script_text_editor.cpp b/editor_modules/editor_code_editor/editor_script_text_editor.cpp
index 5b6d34300..fbd8caf43 100644
--- a/editor_modules/editor_code_editor/editor_script_text_editor.cpp
+++ b/editor_modules/editor_code_editor/editor_script_text_editor.cpp
@@ -1846,7 +1846,7 @@ EditorScriptTextEditor::~EditorScriptTextEditor() {
 	}
 }
 
-static EditorScriptEditorBase *create_editor(const RES &p_resource) {
+EditorScriptEditorBase *EditorScriptTextEditor::create_editor(const RES &p_resource) {
 	if (Object::cast_to<Script>(*p_resource)) {
 		return memnew(EditorScriptTextEditor);
 	}
diff --git a/editor_modules/editor_code_editor/editor_script_text_editor.h b/editor_modules/editor_code_editor/editor_script_text_editor.h
index 45b5226b8..563c6144b 100644
--- a/editor_modules/editor_code_editor/editor_script_text_editor.h
+++ b/editor_modules/editor_code_editor/editor_script_text_editor.h
@@ -153,6 +153,8 @@ class EditorScriptTextEditor : public EditorScriptEditorBase {
 		LOOKUP_SYMBOL,
 	};
 
+	static EditorScriptEditorBase *create_editor(const RES &p_resource);
+
 	void _enable_code_editor();
 
 protected:
diff --git a/editor_modules/editor_code_editor/editor_text_editor.cpp b/editor_modules/editor_code_editor/editor_text_editor.cpp
index 8971da10a..2e63a773d 100644
--- a/editor_modules/editor_code_editor/editor_text_editor.cpp
+++ b/editor_modules/editor_code_editor/editor_text_editor.cpp
@@ -477,7 +477,7 @@ void EditorTextEditor::_bind_methods() {
 	ClassDB::bind_method("_prepare_edit_menu", &EditorTextEditor::_prepare_edit_menu);
 }
 
-static EditorScriptEditorBase *create_editor(const RES &p_resource) {
+EditorScriptEditorBase *EditorTextEditor::create_editor(const RES &p_resource) {
 	if (Object::cast_to<TextFile>(*p_resource)) {
 		return memnew(EditorTextEditor);
 	}
diff --git a/editor_modules/editor_code_editor/editor_text_editor.h b/editor_modules/editor_code_editor/editor_text_editor.h
index 5ac621c4a..5bf24340b 100644
--- a/editor_modules/editor_code_editor/editor_text_editor.h
+++ b/editor_modules/editor_code_editor/editor_text_editor.h
@@ -119,6 +119,8 @@ private:
 		BOOKMARK_REMOVE_ALL,
 	};
 
+	static EditorScriptEditorBase *create_editor(const RES &p_resource);
+
 protected:
 	static void _bind_methods();
 
diff --git a/main/tests/test_string.cpp.old b/main/tests/test_string.cpp.old
index f4c8fd114..25729d807 100644
--- a/main/tests/test_string.cpp.old
+++ b/main/tests/test_string.cpp.old
@@ -1330,3 +1330,5 @@ MainLoop *test() {
 	return nullptr;
 }
 } // namespace TestString
+
+#undef CHECK
\ No newline at end of file
diff --git a/main/tests/test_theme.cpp b/main/tests/test_theme.cpp
index 652aa6a26..6f39ea93f 100644
--- a/main/tests/test_theme.cpp
+++ b/main/tests/test_theme.cpp
@@ -301,3 +301,5 @@ MainLoop *test() {
 	return nullptr;
 }
 } // namespace TestTheme
+
+#undef CHECK
diff --git a/methods.py b/methods.py
index 2dea89882..1f25bfed8 100644
--- a/methods.py
+++ b/methods.py
@@ -13,8 +13,23 @@ from SCons.Script import ARGUMENTS
 from SCons.Script import Glob
 from SCons.Variables.BoolVariable import _text2bool
 
+from pathlib import Path
+from os.path import normpath, basename
 
-def add_source_files(self, sources, files):
+# 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 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 isbasestring(files):
         # Keep SCons project-absolute path as they are (no wildcard support)
@@ -29,7 +44,7 @@ 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
@@ -40,6 +55,70 @@ def add_source_files(self, sources, files):
             continue
         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]
+        if n != (len(folders) - 1):
+            section_name += "/"
+
+    return section_name
+
+
+def add_source_files_scu(self, sources, files, allow_gen=False):
+    if self["scu_build"] 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
diff --git a/scene/gui/box_container.cpp b/scene/gui/box_container.cpp
index 81bc8a6ee..2fa64d2f9 100644
--- a/scene/gui/box_container.cpp
+++ b/scene/gui/box_container.cpp
@@ -32,12 +32,6 @@
 #include "label.h"
 #include "margin_container.h"
 
-struct _MinSizeCache {
-	int min_size;
-	bool will_stretch;
-	int final_size;
-};
-
 void BoxContainer::_resort() {
 	/** First pass, determine minimum size AND amount of stretchable elements */
 
diff --git a/scene/gui/box_container.h b/scene/gui/box_container.h
index 3c5f5a250..c3b936577 100644
--- a/scene/gui/box_container.h
+++ b/scene/gui/box_container.h
@@ -35,6 +35,12 @@
 class BoxContainer : public Container {
 	GDCLASS(BoxContainer, Container);
 
+	struct _MinSizeCache {
+		int min_size;
+		bool will_stretch;
+		int final_size;
+	};
+
 public:
 	enum AlignMode {
 		ALIGN_BEGIN,
diff --git a/scene/gui/line_edit.cpp b/scene/gui/line_edit.cpp
index 4a3e71711..b9fea6ce0 100644
--- a/scene/gui/line_edit.cpp
+++ b/scene/gui/line_edit.cpp
@@ -47,7 +47,7 @@
 #include "editor/editor_settings.h"
 #endif
 
-static bool _is_text_char(CharType c) {
+bool LineEdit::_is_text_char(CharType c) {
 	return !is_symbol(c);
 }
 
diff --git a/scene/gui/line_edit.h b/scene/gui/line_edit.h
index fe3cf83d5..4e1d5c737 100644
--- a/scene/gui/line_edit.h
+++ b/scene/gui/line_edit.h
@@ -149,6 +149,7 @@ private:
 	void _text_changed();
 	void _emit_text_change();
 	bool expand_to_text_length;
+	bool _is_text_char(CharType c);
 
 	void update_cached_width();
 	void update_placeholder_width();
diff --git a/scu_builders.py b/scu_builders.py
new file mode 100644
index 000000000..c8fde9106
--- /dev/null
+++ b/scu_builders.py
@@ -0,0 +1,578 @@
+"""Functions used to generate scu build source files during build time
+"""
+import glob, os
+import math
+from pathlib import Path
+from os.path import normpath, basename
+
+base_folder_path = str(Path(__file__).parent) + "/"
+base_folder_only = os.path.basename(os.path.normpath(base_folder_path))
+_verbose = False
+_is_release_build = False
+_scu_folders = set()
+
+
+def clear_out_existing_files(output_folder, extension):
+    output_folder = os.path.abspath(output_folder)
+    # print("clear_out_existing_files from folder: " + output_folder)
+
+    if not os.path.isdir(output_folder):
+        # folder does not exist or has not been created yet,
+        # no files to clearout. (this is not an error)
+        return
+
+    os.chdir(output_folder)
+
+    for file in glob.glob("*." + extension):
+        # print("removed pre-existing file: " + file)
+        os.remove(file)
+
+
+def folder_not_found(folder):
+    abs_folder = base_folder_path + folder + "/"
+    return not os.path.isdir(abs_folder)
+
+
+def find_files_in_folder(folder, sub_folder, include_list, extension, sought_exceptions, found_exceptions):
+    abs_folder = base_folder_path + folder + "/" + sub_folder
+
+    if not os.path.isdir(abs_folder):
+        print("ERROR " + abs_folder + " not found.")
+        return include_list, found_exceptions
+
+    os.chdir(abs_folder)
+
+    sub_folder_slashed = ""
+    if sub_folder != "":
+        sub_folder_slashed = sub_folder + "/"
+
+    for file in glob.glob("*." + extension):
+
+        simple_name = Path(file).stem
+
+        if file.endswith(".gen.cpp"):
+            continue
+
+        li = '#include "' + folder + "/" + sub_folder_slashed + file + '"'
+
+        if not simple_name in sought_exceptions:
+            include_list.append(li)
+        else:
+            found_exceptions.append(li)
+
+    return include_list, found_exceptions
+
+
+def write_output_file(file_count, include_list, start_line, end_line, output_folder, output_filename_prefix, extension):
+
+    output_folder = os.path.abspath(output_folder)
+
+    if not os.path.isdir(output_folder):
+        # create
+        os.mkdir(output_folder)
+        if not os.path.isdir(output_folder):
+            print("ERROR " + output_folder + " could not be created.")
+            return
+        print("CREATING folder " + output_folder)
+
+    file_text = ""
+
+    for l in range(start_line, end_line):
+        if l < len(include_list):
+            line = include_list[l]
+            li = line + "\n"
+            file_text += li
+
+    num_string = ""
+    if file_count > 0:
+        num_string = "_" + str(file_count)
+
+    short_filename = output_filename_prefix + num_string + ".gen." + extension
+    output_filename = output_folder + "/" + short_filename
+    if _verbose:
+        print("generating: " + short_filename)
+
+    output_path = Path(output_filename)
+    output_path.write_text(file_text, encoding="utf8")
+
+
+def write_exception_output_file(file_count, exception_string, output_folder, output_filename_prefix, extension):
+    output_folder = os.path.abspath(output_folder)
+    if not os.path.isdir(output_folder):
+        print("ERROR " + output_folder + " does not exist.")
+        return
+
+    file_text = exception_string + "\n"
+
+    num_string = ""
+    if file_count > 0:
+        num_string = "_" + str(file_count)
+
+    short_filename = output_filename_prefix + "_exception" + num_string + ".gen." + extension
+    output_filename = output_folder + "/" + short_filename
+
+    if _verbose:
+        print("generating: " + short_filename)
+
+    output_path = Path(output_filename)
+    output_path.write_text(file_text, encoding="utf8")
+
+
+def find_section_name(sub_folder):
+    # Construct a useful name for the section from the path for debug logging
+    section_path = os.path.abspath(base_folder_path + sub_folder) + "/"
+
+    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.append(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]
+        if n != (len(folders) - 1):
+            section_name += "_"
+
+    return section_name
+
+
+# "folders" is a list of folders to add all the files from to add to the SCU
+# "section (like a module)". The name of the scu file will be derived from the first folder
+# (thus e.g. scene/3d becomes scu_scene_3d.gen.cpp)
+
+# "includes_per_scu" limits the number of includes in a single scu file.
+# This allows the module to be built in several translation units instead of just 1.
+# This will usually be slower to compile but will use less memory per compiler instance, which
+# is most relevant in release builds.
+
+# "sought_exceptions" are a list of files (without extension) that contain
+# e.g. naming conflicts, and are therefore not suitable for the scu build.
+# These will automatically be placed in their own separate scu file,
+# which is slow like a normal build, but prevents the naming conflicts.
+# Ideally in these situations, the source code should be changed to prevent naming conflicts.
+
+# "extension" will usually be cpp, but can also be set to c (for e.g. third party libraries that use c)
+def process_folder(folders, sought_exceptions=[], includes_per_scu=0, extension="cpp"):
+    if len(folders) == 0:
+        return
+
+    # Construct the filename prefix from the FIRST folder name
+    # e.g. "scene_3d"
+    out_filename = find_section_name(folders[0])
+
+    found_includes = []
+    found_exceptions = []
+
+    main_folder = folders[0]
+    abs_main_folder = base_folder_path + main_folder
+
+    # Keep a record of all folders that have been processed for SCU,
+    # this enables deciding what to do when we call "add_source_files()"
+    global _scu_folders
+    _scu_folders.add(main_folder)
+
+    # main folder (first)
+    found_includes, found_exceptions = find_files_in_folder(
+        main_folder, "", found_includes, extension, sought_exceptions, found_exceptions
+    )
+
+    # sub folders
+    for d in range(1, len(folders)):
+        found_includes, found_exceptions = find_files_in_folder(
+            main_folder, folders[d], found_includes, extension, sought_exceptions, found_exceptions
+        )
+
+    found_includes = sorted(found_includes)
+
+    # calculate how many lines to write in each file
+    total_lines = len(found_includes)
+
+    # adjust number of output files according to whether DEV or release
+    num_output_files = 1
+    if _is_release_build:
+        # always have a maximum in release
+        includes_per_scu = 8
+        num_output_files = max(math.ceil(total_lines / includes_per_scu), 1)
+    else:
+        if includes_per_scu > 0:
+            num_output_files = max(math.ceil(total_lines / includes_per_scu), 1)
+
+    # error condition
+    if total_lines == 0:
+        return
+
+    lines_per_file = math.ceil(total_lines / num_output_files)
+    lines_per_file = max(lines_per_file, 1)
+
+    start_line = 0
+    file_number = 0
+
+    # These do not vary throughout the loop
+    output_folder = abs_main_folder + "/.scu/"
+    output_filename_prefix = "scu_" + out_filename
+
+    # Clear out any existing files (usually we will be overwriting,
+    # but we want to remove any that are pre-existing that will not be
+    # overwritten, so as to not compile anything stale)
+    clear_out_existing_files(output_folder, extension)
+
+    for file_count in range(0, num_output_files):
+        end_line = start_line + lines_per_file
+
+        # special case to cover rounding error in final file
+        if file_count == (num_output_files - 1):
+            end_line = len(found_includes)
+
+        write_output_file(
+            file_count, found_includes, start_line, end_line, output_folder, output_filename_prefix, extension
+        )
+
+        start_line = end_line
+
+    # Write the exceptions each in their own scu gen file,
+    # so they can effectively compile in "old style / normal build".
+    for exception_count in range(len(found_exceptions)):
+        write_exception_output_file(
+            exception_count, found_exceptions[exception_count], output_folder, output_filename_prefix, extension
+        )
+
+
+def generate_scu_files(verbose, is_release_build):
+
+    print("=============================")
+    print("Single Compilation Unit Build")
+    print("=============================")
+    print("Generating SCU build files")
+    global _verbose
+    _verbose = verbose
+    global _is_release_build
+    _is_release_build = is_release_build
+
+    curr_folder = os.path.abspath("./")
+
+    # check we are running from the correct folder
+    if folder_not_found("core") or folder_not_found("platform") or folder_not_found("scene"):
+        raise RuntimeError("scu_builders.py must be run from the godot folder.")
+        return
+
+    process_folder(["core"])
+    process_folder(["core/bind"])
+    process_folder(["core/config"])
+    process_folder(["core/containers"])
+    process_folder(["core/error"])
+    process_folder(["core/input"])
+    process_folder(["core/log"])
+    process_folder(["core/math"])
+    process_folder(["core/object"])
+    process_folder(["core/os"])
+    process_folder(["core/string"])
+    process_folder(["core/variant"])
+    process_folder(["core/io"])
+    process_folder(["core/crypto"])
+
+    process_folder(["drivers/gles2"])
+    process_folder(["drivers/unix"])
+    process_folder(["drivers/png"])
+
+    process_folder(["editor"])
+    process_folder(["editor/import"])
+    process_folder(["editor/plugins"])
+
+    process_folder(["main"])
+    process_folder(["main/tests"])
+
+    process_folder(
+        [
+            "platform",
+            "android/export",
+            "iphone/export",
+            "javascript/export",
+            "osx/export",
+            #"uwp/export",
+            "windows/export",
+            "x11/export",
+        ]
+    )
+
+    #TODO most of these should be merged per module
+
+    process_folder(["modules/broken_seals_module"])
+    process_folder(["modules/cscript"])
+    process_folder(["modules/csg"])
+
+    process_folder(["modules/database"])
+    process_folder(["modules/database_sqlite"])
+
+    process_folder(["modules/entity_spell_system"])
+    process_folder(["modules/entity_spell_system/data/atlases"])
+    process_folder(["modules/entity_spell_system/data/auras"])
+    process_folder(["modules/entity_spell_system/data/items"])
+    process_folder(["modules/entity_spell_system/data/loot"])
+    process_folder(["modules/entity_spell_system/data/species"])
+    process_folder(["modules/entity_spell_system/data/spells"])
+    process_folder(["modules/entity_spell_system/database"])
+    process_folder(["modules/entity_spell_system/drag_and_drop"])
+    process_folder(["modules/entity_spell_system/editor"])
+    process_folder(["modules/entity_spell_system/entities"])
+    process_folder(["modules/entity_spell_system/entities/ai"])
+    process_folder(["modules/entity_spell_system/entities/auras"])
+    process_folder(["modules/entity_spell_system/entities/data"])
+    process_folder(["modules/entity_spell_system/entities/resources"])
+    process_folder(["modules/entity_spell_system/entities/skills"])
+    process_folder(["modules/entity_spell_system/entities/stats"])
+    process_folder(["modules/entity_spell_system/formations"])
+    process_folder(["modules/entity_spell_system/infos"])
+    process_folder(["modules/entity_spell_system/inventory"])
+    process_folder(["modules/entity_spell_system/material_cache"])
+    process_folder(["modules/entity_spell_system/pipelines"])
+    process_folder(["modules/entity_spell_system/profiles"])
+    process_folder(["modules/entity_spell_system/profiles/actionbar"])
+    process_folder(["modules/entity_spell_system/profiles/input"])
+    process_folder(["modules/entity_spell_system/projectiles/3d"])
+    process_folder(["modules/entity_spell_system/props"])
+    process_folder(["modules/entity_spell_system/singletons"])
+    process_folder(["modules/entity_spell_system/skeleton"])
+    process_folder(["modules/entity_spell_system/spawners"])
+    process_folder(["modules/entity_spell_system/utility"])
+
+    process_folder(["modules/fastnoise"])
+
+    process_folder(["modules/gdnative"])
+    process_folder(["modules/gdnative/gdnative"])
+    process_folder(["modules/gdnative/nativescript"])
+    #process_folder(["modules/gdnative/arvr"])
+    process_folder(["modules/gdnative/pluginscript"])
+    process_folder(["modules/gdnative/net"])
+
+    process_folder(["modules/gdscript"])
+    #process_folder(["modules/gdscript/language_server"])
+
+    process_folder(["modules/gridmap"])
+    process_folder(["modules/gridmap/geometry_parser"])
+
+    process_folder(["modules/http_server_simple"])
+
+    process_folder(["modules/lz4"])
+
+    process_folder(["modules/material_maker"])
+    process_folder(["modules/material_maker/algos"])
+    process_folder(["modules/material_maker/editor"])
+    process_folder(["modules/material_maker/editor/widgets/color_picker_popup"])
+    process_folder(["modules/material_maker/editor/widgets/curve_edit"])
+    process_folder(["modules/material_maker/editor/widgets/file_dialog"])
+    process_folder(["modules/material_maker/editor/widgets/float_edit"])
+    process_folder(["modules/material_maker/editor/widgets/gradient_editor"])
+    process_folder(["modules/material_maker/editor/widgets/image_picker_button"])
+    process_folder(["modules/material_maker/editor/widgets/mm_dnd_color_picker_button"])
+    process_folder(["modules/material_maker/editor/widgets/polygon_edit"])
+    process_folder(["modules/material_maker/editor/widgets/tones_editor"])
+    process_folder(["modules/material_maker/nodes"])
+    process_folder(["modules/material_maker/nodes/bases"])
+    process_folder(["modules/material_maker/nodes/filter"])
+    process_folder(["modules/material_maker/nodes/gradient"])
+    process_folder(["modules/material_maker/nodes/noise"])
+    process_folder(["modules/material_maker/nodes/other"])
+    process_folder(["modules/material_maker/nodes/pattern"])
+    process_folder(["modules/material_maker/nodes/sdf2d"])
+    process_folder(["modules/material_maker/nodes/sdf3d"])
+    process_folder(["modules/material_maker/nodes/simple"])
+    process_folder(["modules/material_maker/nodes/transform"])
+    process_folder(["modules/material_maker/nodes/uniform"])
+
+    process_folder(["modules/mbedtls"])
+
+    process_folder(["modules/mesh_data_resource"])
+    process_folder(["modules/mesh_data_resource/editor"])
+    process_folder(["modules/mesh_data_resource/editor/utilities"])
+    process_folder(["modules/mesh_data_resource/editor/uv_editor"])
+    process_folder(["modules/mesh_data_resource/nodes"])
+    process_folder(["modules/mesh_data_resource/plugin"])
+    process_folder(["modules/mesh_data_resource/plugin_gltf"])
+    process_folder(["modules/mesh_data_resource/props"])
+    process_folder(["modules/mesh_data_resource/props_2d"])
+
+    process_folder(["modules/mesh_utils"])
+
+    process_folder(["modules/navigation"])
+    process_folder(["modules/navigation_dummy"])
+    process_folder(["modules/navigation_geometry_parsers"])
+    process_folder(["modules/navigation_geometry_parsers/geometry_parser_2d"])
+    process_folder(["modules/navigation_geometry_parsers/geometry_parser_3d"])
+    process_folder(["modules/navigation_mesh_generator"])
+    process_folder(["modules/navigation_mesh_generator/editor"])
+
+    process_folder(["modules/network_synchronizer"])
+
+    process_folder(["modules/paint"])
+    process_folder(["modules/paint/actions"])
+    process_folder(["modules/paint/editor"])
+    process_folder(["modules/paint/nodes"])
+    process_folder(["modules/paint/ui"])
+    process_folder(["modules/paint/ui/property_inspectors"])
+
+    process_folder(["modules/props"])
+    process_folder(["modules/props/clutter"])
+    process_folder(["modules/props/editor"])
+    process_folder(["modules/props/jobs"])
+    process_folder(["modules/props/lights"])
+    process_folder(["modules/props/material_cache"])
+    process_folder(["modules/props/props"])
+    process_folder(["modules/props/singleton"])
+    process_folder(["modules/props/tiled_wall"])
+
+    process_folder(["modules/props_2d"])
+    process_folder(["modules/props_2d/clutter"])
+    process_folder(["modules/props_2d/editor"])
+    process_folder(["modules/props_2d/jobs"])
+    process_folder(["modules/props_2d/lights"])
+    process_folder(["modules/props_2d/material_cache"])
+    process_folder(["modules/props_2d/props"])
+    process_folder(["modules/props_2d/singleton"])
+    process_folder(["modules/props_2d/tiled_wall"])
+
+    process_folder(["modules/skeleton_2d"])
+    process_folder(["modules/skeleton_2d/editor"])
+    process_folder(["modules/skeleton_2d/nodes"])
+    process_folder(["modules/skeleton_2d/resources"])
+    process_folder(["modules/skeleton_3d"])
+    process_folder(["modules/skeleton_3d/editor"])
+    process_folder(["modules/skeleton_3d/nodes"])
+    process_folder(["modules/skeleton_3d/resources"])
+
+    process_folder(["modules/steering_ai"])
+    process_folder(["modules/steering_ai/agents"])
+    process_folder(["modules/steering_ai/behaviors"])
+    process_folder(["modules/steering_ai/proximities"])
+
+    process_folder(["modules/terraman"])
+    process_folder(["modules/terraman/areas"])
+    process_folder(["modules/terraman/data"])
+    process_folder(["modules/terraman/level_generator"])
+    process_folder(["modules/terraman/library"])
+    process_folder(["modules/terraman/meshers"])
+    process_folder(["modules/terraman/meshers/blocky"])
+    process_folder(["modules/terraman/meshers/default"])
+    process_folder(["modules/terraman/nodes"])
+    process_folder(["modules/terraman/world"])
+    process_folder(["modules/terraman/world/blocky"])
+    process_folder(["modules/terraman/world/default"])
+    process_folder(["modules/terraman/world/jobs"])
+
+    process_folder(["modules/terraman_2d"])
+    process_folder(["modules/terraman_2d/areas"])
+    process_folder(["modules/terraman_2d/data"])
+    process_folder(["modules/terraman_2d/level_generator"])
+    process_folder(["modules/terraman_2d/library"])
+    process_folder(["modules/terraman_2d/meshers"])
+    process_folder(["modules/terraman_2d/meshers/default"])
+    process_folder(["modules/terraman_2d/meshers/isometric"])
+    process_folder(["modules/terraman_2d/meshers/simple"])
+    process_folder(["modules/terraman_2d/nodes"])
+    process_folder(["modules/terraman_2d/world"])
+    process_folder(["modules/terraman_2d/world/default"])
+    process_folder(["modules/terraman_2d/world/isometric"])
+    process_folder(["modules/terraman_2d/world/jobs"])
+    process_folder(["modules/terraman_2d/world/simple"])
+
+    process_folder(["modules/texture_packer"])
+    process_folder(["modules/texture_packer/layers"])
+    process_folder(["modules/texture_packer/rectpack2D"])
+    process_folder(["modules/texture_packer/texture_resource"])
+
+    process_folder(["modules/tile_map"])
+    process_folder(["modules/tile_map/geometry_parser"])
+
+    process_folder(["modules/ui_extensions"])
+
+    process_folder(["modules/unit_test"])
+
+    process_folder(["modules/users"])
+    process_folder(["modules/users/managers"])
+    process_folder(["modules/users/singleton"])
+    process_folder(["modules/users/users"])
+    process_folder(["modules/users/web/middleware"])
+    process_folder(["modules/users/web/web_nodes"])
+
+    process_folder(["modules/voxelman"])
+    process_folder(["modules/voxelman/areas"])
+    process_folder(["modules/voxelman/data"])
+    process_folder(["modules/voxelman/level_generator"])
+    process_folder(["modules/voxelman/library"])
+    process_folder(["modules/voxelman/meshers"])
+    process_folder(["modules/voxelman/meshers/blocky"])
+    process_folder(["modules/voxelman/meshers/cubic"])
+    process_folder(["modules/voxelman/meshers/default"])
+    process_folder(["modules/voxelman/meshers/marching_cubes"])
+    process_folder(["modules/voxelman/nodes"])
+    process_folder(["modules/voxelman/world"])
+    process_folder(["modules/voxelman/world/blocky"])
+    process_folder(["modules/voxelman/world/cubic"])
+    process_folder(["modules/voxelman/world/default"])
+    process_folder(["modules/voxelman/world/jobs"])
+    process_folder(["modules/voxelman/world/marching_cubes"])
+
+    process_folder(["modules/web"])
+    process_folder(["modules/web/database"])
+    process_folder(["modules/web/editor"])
+    process_folder(["modules/web/html"])
+    process_folder(["modules/web/http"])
+    process_folder(["modules/web/nodes/admin_panel"])
+    process_folder(["modules/web/nodes/folder_serve_nodes"])
+    process_folder(["modules/web/nodes/list_page"])
+    process_folder(["modules/web/nodes/message_page"])
+    process_folder(["modules/web/nodes/paged_article"])
+    process_folder(["modules/web/nodes/redirect"])
+    process_folder(["modules/web/nodes/static_pages"])
+
+    process_folder(["modules/websocket"])
+
+    process_folder(["modules/wfc"])
+
+    #Editor Modules
+    process_folder(["editor_modules/editor_code_editor"])
+
+    process_folder(["editor_modules/gltf"])
+    process_folder(["editor_modules/gltf/structures"])
+    process_folder(["editor_modules/gltf/extensions"])
+    process_folder(["editor_modules/gltf/extensions/physics"])
+
+    process_folder(["editor_modules/plugin_refresher"])
+
+    process_folder(["editor_modules/shader_editor"])
+    process_folder(["editor_modules/text_editor"])
+
+    #process_folder(["modules/fbx"])
+    #process_folder(["modules/fbx/tools"])
+    #process_folder(["modules/fbx/data"])
+    #process_folder(["modules/fbx/fbx_parser"])
+
+    process_folder(["scene"])
+    process_folder(["scene/audio"])
+    process_folder(["scene/debugger"])
+    process_folder(["scene/2d"])
+    process_folder(["scene/3d"])
+    process_folder(["scene/animation"])
+    process_folder(["scene/gui"])
+    process_folder(["scene/main"])
+    process_folder(["scene/resources"])
+
+    process_folder(["servers"])
+    process_folder(["servers/rendering"])
+    process_folder(["servers/rendering/portals"])
+    process_folder(["servers/physics_2d"])
+    process_folder(["servers/physics"])
+    process_folder(["servers/physics/joints"])
+    process_folder(["servers/audio"])
+    process_folder(["servers/audio/effects"])
+
+    # Finally change back the path to the calling folder
+    os.chdir(curr_folder)
+
+    return _scu_folders
\ No newline at end of file
diff --git a/servers/physics/joints/hinge_joint_sw.cpp b/servers/physics/joints/hinge_joint_sw.cpp
index 1a854ca27..151e2cee6 100644
--- a/servers/physics/joints/hinge_joint_sw.cpp
+++ b/servers/physics/joints/hinge_joint_sw.cpp
@@ -49,7 +49,7 @@ subject to the following restrictions:
 
 #include "hinge_joint_sw.h"
 
-static void plane_space(const Vector3 &n, Vector3 &p, Vector3 &q) {
+void HingeJointSW::plane_space(const Vector3 &n, Vector3 &p, Vector3 &q) {
 	if (Math::abs(n.z) > Math_SQRT12) {
 		// choose p in y-z plane
 		real_t a = n[1] * n[1] + n[2] * n[2];
@@ -382,7 +382,7 @@ void	HingeJointSW::updateRHS(real_t	timeStep)
 }
 */
 
-static _FORCE_INLINE_ real_t atan2fast(real_t y, real_t x) {
+real_t HingeJointSW::atan2fast(real_t y, real_t x) {
 	real_t coeff_1 = Math_PI / 4.0f;
 	real_t coeff_2 = 3.0f * coeff_1;
 	real_t abs_y = Math::abs(y);
diff --git a/servers/physics/joints/hinge_joint_sw.h b/servers/physics/joints/hinge_joint_sw.h
index c0c99deb2..45d8837fe 100644
--- a/servers/physics/joints/hinge_joint_sw.h
+++ b/servers/physics/joints/hinge_joint_sw.h
@@ -94,6 +94,9 @@ class HingeJointSW : public JointSW {
 
 	real_t m_appliedImpulse;
 
+	void plane_space(const Vector3 &n, Vector3 &p, Vector3 &q);
+	_FORCE_INLINE_ real_t atan2fast(real_t y, real_t x);
+
 public:
 	virtual PhysicsServer::JointType get_type() const { return PhysicsServer::JOINT_HINGE; }
 
diff --git a/servers/physics/joints/slider_joint_sw.cpp b/servers/physics/joints/slider_joint_sw.cpp
index 7113503d6..7e2040890 100644
--- a/servers/physics/joints/slider_joint_sw.cpp
+++ b/servers/physics/joints/slider_joint_sw.cpp
@@ -57,7 +57,7 @@ April 04, 2008
 
 //-----------------------------------------------------------------------------
 
-static _FORCE_INLINE_ real_t atan2fast(real_t y, real_t x) {
+real_t SliderJointSW::atan2fast(real_t y, real_t x) {
 	real_t coeff_1 = Math_PI / 4.0f;
 	real_t coeff_2 = 3.0f * coeff_1;
 	real_t abs_y = Math::abs(y);
diff --git a/servers/physics/joints/slider_joint_sw.h b/servers/physics/joints/slider_joint_sw.h
index bf5502add..801854c80 100644
--- a/servers/physics/joints/slider_joint_sw.h
+++ b/servers/physics/joints/slider_joint_sw.h
@@ -149,6 +149,9 @@ protected:
 	//------------------------
 	void initParams();
 
+private:
+	_FORCE_INLINE_ real_t atan2fast(real_t y, real_t x);
+
 public:
 	// constructors
 	SliderJointSW(BodySW *rbA, BodySW *rbB, const Transform &frameInA, const Transform &frameInB);