Improve embedded PCK loading and exporting.

Windows export process:
  Limit size of executable with embedded PCK to 4 GB.
  Use "rcedit" before embedding PCK.
  Capture and process "rcedit" errors.

Windows, Linux:
  Add support for PCK loading from executable "pck" section.

core/io/file_access_pack.cpp

@@ -32,6 +32,7 @@
 
 #include "core/io/file_access_encrypted.h"
 #include "core/object/script_language.h"
+#include "core/os/os.h"
 #include "core/version.h"
 
 #include <stdio.h>
@@ -131,32 +132,69 @@ bool PackedSourcePCK::try_open_pack(const String &p_path, bool p_replace_files,
 		return false;
 	}
 
-	f->seek(p_offset);
+	bool pck_header_found = false;
 
+	// Search for the header at the start offset - standalone PCK file.
+	f->seek(p_offset);
 	uint32_t magic = f->get_32();
+	if (magic == PACK_HEADER_MAGIC) {
+		pck_header_found = true;
+	}
 
-	if (magic != PACK_HEADER_MAGIC) {
-		// loading with offset feature not supported for self contained exe files
-		ERR_FAIL_COND_V_MSG(p_offset != 0, false, "Loading self-contained executable with offset not supported.");
+	// Search for the header in the executable "pck" section - self contained executable.
+	if (!pck_header_found) {
+		// Loading with offset feature not supported for self contained exe files.
+		if (p_offset != 0) {
+			ERR_FAIL_V_MSG(false, "Loading self-contained executable with offset not supported.");
+		}
 
-		//maybe at the end.... self contained exe
-		f->seek_end();
-		f->seek(f->get_position() - 4);
-		magic = f->get_32();
-		if (magic != PACK_HEADER_MAGIC) {
-			return false;
+		int64_t pck_off = OS::get_singleton()->get_embedded_pck_offset();
+		if (pck_off != 0) {
+			// Search for the header, in case PCK start and section have different alignment.
+			for (int i = 0; i < 8; i++) {
+				f->seek(pck_off);
+				magic = f->get_32();
+				if (magic == PACK_HEADER_MAGIC) {
+#ifdef DEBUG_ENABLED
+					print_verbose("PCK header found in executable pck section, loading from offset 0x" + String::num_int64(pck_off - 4, 16));
+#endif
+					pck_header_found = true;
+					break;
+				}
+				pck_off++;
+			}
 		}
-		f->seek(f->get_position() - 12);
+	}
 
-		uint64_t ds = f->get_64();
-		f->seek(f->get_position() - ds - 8);
+	// Search for the header at the end of file - self contained executable.
+	if (!pck_header_found) {
+		// Loading with offset feature not supported for self contained exe files.
+		if (p_offset != 0) {
+			ERR_FAIL_V_MSG(false, "Loading self-contained executable with offset not supported.");
+		}
 
+		f->seek_end();
+		f->seek(f->get_position() - 4);
 		magic = f->get_32();
-		if (magic != PACK_HEADER_MAGIC) {
-			return false;
+
+		if (magic == PACK_HEADER_MAGIC) {
+			f->seek(f->get_position() - 12);
+			uint64_t ds = f->get_64();
+			f->seek(f->get_position() - ds - 8);
+			magic = f->get_32();
+			if (magic == PACK_HEADER_MAGIC) {
+#ifdef DEBUG_ENABLED
+				print_verbose("PCK header found at the end of executable, loading from offset 0x" + String::num_int64(f->get_position() - 4, 16));
+#endif
+				pck_header_found = true;
+			}
 		}
 	}
 
+	if (!pck_header_found) {
+		return false;
+	}
+
 	uint32_t version = f->get_32();
 	uint32_t ver_major = f->get_32();
 	uint32_t ver_minor = f->get_32();

core/os/os.cpp

@@ -237,6 +237,11 @@ String OS::get_locale_language() const {
 	return get_locale().left(3).replace("_", "");
 }
 
+// Embedded PCK offset.
+uint64_t OS::get_embedded_pck_offset() const {
+	return 0;
+}
+
 // Helper function to ensure that a dir name/path will be valid on the OS
 String OS::get_safe_dir_name(const String &p_dir_name, bool p_allow_dir_separator) const {
 	Vector<String> invalid_chars = String(": * ? \" < > |").split(" ");

core/os/os.h

@@ -264,6 +264,8 @@ public:
 	virtual String get_locale() const;
 	String get_locale_language() const;
 
+	virtual uint64_t get_embedded_pck_offset() const;
+
 	String get_safe_dir_name(const String &p_dir_name, bool p_allow_dir_separator = false) const;
 	virtual String get_godot_dir_name() const;
 

editor/editor_export.cpp

@@ -1820,6 +1820,18 @@ bool EditorExportPlatformPC::can_export(const Ref<EditorExportPreset> &p_preset,
 
 Error EditorExportPlatformPC::export_project(const Ref<EditorExportPreset> &p_preset, bool p_debug, const String &p_path, int p_flags) {
 	ExportNotifier notifier(*this, p_preset, p_debug, p_path, p_flags);
+	Error err = prepare_template(p_preset, p_debug, p_path, p_flags);
+	if (err == OK) {
+		err = export_project_data(p_preset, p_debug, p_path, p_flags);
+	}
+
+	return err;
+}
+
+Error EditorExportPlatformPC::prepare_template(const Ref<EditorExportPreset> &p_preset, bool p_debug, const String &p_path, int p_flags) {
+	if (!DirAccess::exists(p_path.get_base_dir())) {
+		return ERR_FILE_BAD_PATH;
+	}
 
 	String custom_debug = p_preset->get("custom_template/debug");
 	String custom_release = p_preset->get("custom_template/release");
@@ -1841,49 +1853,52 @@ Error EditorExportPlatformPC::export_project(const Ref<EditorExportPreset> &p_pr
 	da->make_dir_recursive(p_path.get_base_dir());
 	Error err = da->copy(template_path, p_path, get_chmod_flags());
 
-	if (err == OK) {
-		String pck_path;
-		if (p_preset->get("binary_format/embed_pck")) {
-			pck_path = p_path;
-		} else {
-			pck_path = p_path.get_basename() + ".pck";
-		}
+	return err;
+}
 
-		Vector<SharedObject> so_files;
+Error EditorExportPlatformPC::export_project_data(const Ref<EditorExportPreset> &p_preset, bool p_debug, const String &p_path, int p_flags) {
+	String pck_path;
+	if (p_preset->get("binary_format/embed_pck")) {
+		pck_path = p_path;
+	} else {
+		pck_path = p_path.get_basename() + ".pck";
+	}
 
-		int64_t embedded_pos;
-		int64_t embedded_size;
-		err = save_pack(p_preset, p_debug, pck_path, &so_files, p_preset->get("binary_format/embed_pck"), &embedded_pos, &embedded_size);
-		if (err == OK && p_preset->get("binary_format/embed_pck")) {
-			if (embedded_size >= 0x100000000 && !p_preset->get("binary_format/64_bits")) {
-				EditorNode::get_singleton()->show_warning(TTR("On 32-bit exports the embedded PCK cannot be bigger than 4 GiB."));
-				return ERR_INVALID_PARAMETER;
-			}
+	Vector<SharedObject> so_files;
 
-			err = fixup_embedded_pck(p_path, embedded_pos, embedded_size);
+	int64_t embedded_pos;
+	int64_t embedded_size;
+	Error err = save_pack(p_preset, p_debug, pck_path, &so_files, p_preset->get("binary_format/embed_pck"), &embedded_pos, &embedded_size);
+	if (err == OK && p_preset->get("binary_format/embed_pck")) {
+		if (embedded_size >= 0x100000000 && !p_preset->get("binary_format/64_bits")) {
+			EditorNode::get_singleton()->show_warning(TTR("On 32-bit exports the embedded PCK cannot be bigger than 4 GiB."));
+			return ERR_INVALID_PARAMETER;
 		}
 
-		if (err == OK && !so_files.is_empty()) {
-			// If shared object files, copy them.
-			for (int i = 0; i < so_files.size() && err == OK; i++) {
-				String src_path = ProjectSettings::get_singleton()->globalize_path(so_files[i].path);
-				String target_path;
-				if (so_files[i].target.is_empty()) {
-					target_path = p_path.get_base_dir().plus_file(src_path.get_file());
-				} else {
-					target_path = p_path.get_base_dir().plus_file(so_files[i].target).plus_file(src_path.get_file());
-				}
+		err = fixup_embedded_pck(p_path, embedded_pos, embedded_size);
+	}
 
-				if (da->dir_exists(src_path)) {
-					err = da->make_dir_recursive(target_path);
-					if (err == OK) {
-						err = da->copy_dir(src_path, target_path, -1, true);
-					}
-				} else {
-					err = da->copy(src_path, target_path);
-					if (err == OK) {
-						err = sign_shared_object(p_preset, p_debug, target_path);
-					}
+	if (err == OK && !so_files.is_empty()) {
+		// If shared object files, copy them.
+		Ref<DirAccess> da = DirAccess::create(DirAccess::ACCESS_FILESYSTEM);
+		for (int i = 0; i < so_files.size() && err == OK; i++) {
+			String src_path = ProjectSettings::get_singleton()->globalize_path(so_files[i].path);
+			String target_path;
+			if (so_files[i].target.is_empty()) {
+				target_path = p_path.get_base_dir().plus_file(src_path.get_file());
+			} else {
+				target_path = p_path.get_base_dir().plus_file(so_files[i].target).plus_file(src_path.get_file());
+			}
+
+			if (da->dir_exists(src_path)) {
+				err = da->make_dir_recursive(target_path);
+				if (err == OK) {
+					err = da->copy_dir(src_path, target_path, -1, true);
+				}
+			} else {
+				err = da->copy(src_path, target_path);
+				if (err == OK) {
+					err = sign_shared_object(p_preset, p_debug, target_path);
 				}
 			}
 		}

editor/editor_export.h

@@ -442,6 +442,10 @@ public:
 	virtual Error sign_shared_object(const Ref<EditorExportPreset> &p_preset, bool p_debug, const String &p_path);
 	virtual String get_template_file_name(const String &p_target, const String &p_arch) const = 0;
 
+	Error prepare_template(const Ref<EditorExportPreset> &p_preset, bool p_debug, const String &p_path, int p_flags);
+	Error export_project_data(const Ref<EditorExportPreset> &p_preset, bool p_debug, const String &p_path, int p_flags);
+
+	void set_extension(const String &p_extension, const String &p_feature_key = "default");
 	void set_name(const String &p_name);
 	void set_os_name(const String &p_name);
 

platform/linuxbsd/os_linuxbsd.cpp

@@ -242,6 +242,91 @@ bool OS_LinuxBSD::_check_internal_feature_support(const String &p_feature) {
 	return p_feature == "pc";
 }
 
+uint64_t OS_LinuxBSD::get_embedded_pck_offset() const {
+	Ref<FileAccess> f = FileAccess::open(get_executable_path(), FileAccess::READ);
+	if (f.is_null()) {
+		return 0;
+	}
+
+	// Read and check ELF magic number.
+	{
+		uint32_t magic = f->get_32();
+		if (magic != 0x464c457f) { // 0x7F + "ELF"
+			return 0;
+		}
+	}
+
+	// Read program architecture bits from class field.
+	int bits = f->get_8() * 32;
+
+	// Get info about the section header table.
+	int64_t section_table_pos;
+	int64_t section_header_size;
+	if (bits == 32) {
+		section_header_size = 40;
+		f->seek(0x20);
+		section_table_pos = f->get_32();
+		f->seek(0x30);
+	} else { // 64
+		section_header_size = 64;
+		f->seek(0x28);
+		section_table_pos = f->get_64();
+		f->seek(0x3c);
+	}
+	int num_sections = f->get_16();
+	int string_section_idx = f->get_16();
+
+	// Load the strings table.
+	uint8_t *strings;
+	{
+		// Jump to the strings section header.
+		f->seek(section_table_pos + string_section_idx * section_header_size);
+
+		// Read strings data size and offset.
+		int64_t string_data_pos;
+		int64_t string_data_size;
+		if (bits == 32) {
+			f->seek(f->get_position() + 0x10);
+			string_data_pos = f->get_32();
+			string_data_size = f->get_32();
+		} else { // 64
+			f->seek(f->get_position() + 0x18);
+			string_data_pos = f->get_64();
+			string_data_size = f->get_64();
+		}
+
+		// Read strings data.
+		f->seek(string_data_pos);
+		strings = (uint8_t *)memalloc(string_data_size);
+		if (!strings) {
+			return 0;
+		}
+		f->get_buffer(strings, string_data_size);
+	}
+
+	// Search for the "pck" section.
+	int64_t off = 0;
+	for (int i = 0; i < num_sections; ++i) {
+		int64_t section_header_pos = section_table_pos + i * section_header_size;
+		f->seek(section_header_pos);
+
+		uint32_t name_offset = f->get_32();
+		if (strcmp((char *)strings + name_offset, "pck") == 0) {
+			if (bits == 32) {
+				f->seek(section_header_pos + 0x10);
+				off = f->get_32();
+			} else { // 64
+				f->seek(section_header_pos + 0x18);
+				off = f->get_64();
+			}
+			break;
+		}
+	}
+	memfree(strings);
+
+	return off;
+}
+
 String OS_LinuxBSD::get_config_path() const {
 	if (has_environment("XDG_CONFIG_HOME")) {
 		if (get_environment("XDG_CONFIG_HOME").is_absolute_path()) {

platform/linuxbsd/os_linuxbsd.h

@@ -78,6 +78,8 @@ public:
 
 	virtual MainLoop *get_main_loop() const override;
 
+	virtual uint64_t get_embedded_pck_offset() const override;
+
 	virtual String get_config_path() const override;
 	virtual String get_data_path() const override;
 	virtual String get_cache_path() const override;

platform/windows/export/export_plugin.cpp

@@ -54,16 +54,23 @@ Error EditorExportPlatformWindows::_export_debug_script(const Ref<EditorExportPr
 }
 
 Error EditorExportPlatformWindows::export_project(const Ref<EditorExportPreset> &p_preset, bool p_debug, const String &p_path, int p_flags) {
-	Error err = EditorExportPlatformPC::export_project(p_preset, p_debug, p_path, p_flags);
-
-	if (err != OK) {
-		return err;
+	String pck_path = p_path;
+	if (p_preset->get("binary_format/embed_pck")) {
+		pck_path = p_path.get_basename() + ".tmp";
+	}
+	Error err = EditorExportPlatformPC::prepare_template(p_preset, p_debug, pck_path, p_flags);
+	if (p_preset->get("application/modify_resources") && err == OK) {
+		err = _rcedit_add_data(p_preset, pck_path);
+	}
+	if (err == OK) {
+		err = EditorExportPlatformPC::export_project_data(p_preset, p_debug, pck_path, p_flags);
 	}
-
-	_rcedit_add_data(p_preset, p_path);
-
 	if (p_preset->get("codesign/enable") && err == OK) {
-		err = _code_sign(p_preset, p_path);
+		err = _code_sign(p_preset, pck_path);
+	}
+	if (p_preset->get("binary_format/embed_pck") && err == OK) {
+		Ref<DirAccess> tmp_dir = DirAccess::create_for_path(p_path.get_base_dir());
+		err = tmp_dir->rename(pck_path, p_path);
 	}
 
 	String app_name;
@@ -117,6 +124,7 @@ void EditorExportPlatformWindows::get_export_options(List<ExportOption> *r_optio
 	r_options->push_back(ExportOption(PropertyInfo(Variant::STRING, "codesign/description"), ""));
 	r_options->push_back(ExportOption(PropertyInfo(Variant::PACKED_STRING_ARRAY, "codesign/custom_options"), PackedStringArray()));
 
+	r_options->push_back(ExportOption(PropertyInfo(Variant::BOOL, "application/modify_resources"), true));
 	r_options->push_back(ExportOption(PropertyInfo(Variant::STRING, "application/icon", PROPERTY_HINT_FILE, "*.ico"), ""));
 	r_options->push_back(ExportOption(PropertyInfo(Variant::STRING, "application/file_version", PROPERTY_HINT_PLACEHOLDER_TEXT, "1.0.0.0"), ""));
 	r_options->push_back(ExportOption(PropertyInfo(Variant::STRING, "application/product_version", PROPERTY_HINT_PLACEHOLDER_TEXT, "1.0.0.0"), ""));
@@ -127,17 +135,20 @@ void EditorExportPlatformWindows::get_export_options(List<ExportOption> *r_optio
 	r_options->push_back(ExportOption(PropertyInfo(Variant::STRING, "application/trademarks"), ""));
 }
 
-void EditorExportPlatformWindows::_rcedit_add_data(const Ref<EditorExportPreset> &p_preset, const String &p_path) {
+Error EditorExportPlatformWindows::_rcedit_add_data(const Ref<EditorExportPreset> &p_preset, const String &p_path) {
 	String rcedit_path = EditorSettings::get_singleton()->get("export/windows/rcedit");
 
 	if (rcedit_path.is_empty()) {
 		WARN_PRINT("The rcedit tool is not configured in the Editor Settings (Export > Windows > Rcedit). No custom icon or app information data will be embedded in the exported executable.");
-		return;
+		return ERR_FILE_NOT_FOUND;
 	}
 
 	if (!FileAccess::exists(rcedit_path)) {
 		ERR_PRINT("Could not find rcedit executable at " + rcedit_path + ", no icon or app information data will be included.");
-		return;
+		return ERR_FILE_NOT_FOUND;
+	}
+	if (rcedit_path.is_empty()) {
+		rcedit_path = "rcedit"; // try to run signtool from PATH
 	}
 
 #ifndef WINDOWS_ENABLED
@@ -146,7 +157,7 @@ void EditorExportPlatformWindows::_rcedit_add_data(const Ref<EditorExportPreset>
 
 	if (!wine_path.is_empty() && !FileAccess::exists(wine_path)) {
 		ERR_PRINT("Could not find wine executable at " + wine_path + ", no icon or app information data will be included.");
-		return;
+		return ERR_FILE_NOT_FOUND;
 	}
 
 	if (wine_path.is_empty()) {
@@ -204,13 +215,22 @@ void EditorExportPlatformWindows::_rcedit_add_data(const Ref<EditorExportPreset>
 		args.push_back(trademarks);
 	}
 
-#ifdef WINDOWS_ENABLED
-	OS::get_singleton()->execute(rcedit_path, args);
-#else
+#ifndef WINDOWS_ENABLED
 	// On non-Windows we need WINE to run rcedit
 	args.push_front(rcedit_path);
-	OS::get_singleton()->execute(wine_path, args);
+	rcedit_path = wine_path;
 #endif
+
+	String str;
+	Error err = OS::get_singleton()->execute(rcedit_path, args, &str, nullptr, true);
+	ERR_FAIL_COND_V(err != OK, err);
+	print_line("rcedit (" + p_path + "): " + str);
+
+	if (str.find("Fatal error") != -1) {
+		return FAILED;
+	}
+
+	return OK;
 }
 
 Error EditorExportPlatformWindows::_code_sign(const Ref<EditorExportPreset> &p_preset, const String &p_path) {
@@ -417,6 +437,10 @@ bool EditorExportPlatformWindows::can_export(const Ref<EditorExportPreset> &p_pr
 Error EditorExportPlatformWindows::fixup_embedded_pck(const String &p_path, int64_t p_embedded_start, int64_t p_embedded_size) const {
 	// Patch the header of the "pck" section in the PE file so that it corresponds to the embedded data
 
+	if (p_embedded_size + p_embedded_start >= 0x100000000) { // Check for total executable size
+		ERR_FAIL_V_MSG(ERR_INVALID_DATA, "Windows executables cannot be >= 4 GiB.");
+	}
+
 	Ref<FileAccess> f = FileAccess::open(p_path, FileAccess::READ_WRITE);
 	if (f.is_null()) {
 		return ERR_CANT_OPEN;

platform/windows/export/export_plugin.h

@@ -38,7 +38,7 @@
 #include "platform/windows/logo.gen.h"
 
 class EditorExportPlatformWindows : public EditorExportPlatformPC {
-	void _rcedit_add_data(const Ref<EditorExportPreset> &p_preset, const String &p_path);
+	Error _rcedit_add_data(const Ref<EditorExportPreset> &p_preset, const String &p_path);
 	Error _code_sign(const Ref<EditorExportPreset> &p_preset, const String &p_path);
 	Error _export_debug_script(const Ref<EditorExportPreset> &p_preset, const String &p_app_name, const String &p_pkg_name, const String &p_path);
 

platform/windows/godot_windows.cpp

@@ -39,7 +39,18 @@
 #ifndef TOOLS_ENABLED
 #if defined _MSC_VER
 #pragma section("pck", read)
-__declspec(allocate("pck")) static const char dummy[8] = { 0 };
+__declspec(allocate("pck")) static char dummy[8] = { 0 };
+
+// Dummy function to prevent LTO from discarding "pck" section.
+extern "C" char *__cdecl pck_section_dummy_call() {
+	return &dummy[0];
+};
+#if defined _AMD64_
+#pragma comment(linker, "/include:pck_section_dummy_call")
+#elif defined _X86_
+#pragma comment(linker, "/include:_pck_section_dummy_call")
+#endif
+
 #elif defined __GNUC__
 static const char dummy[8] __attribute__((section("pck"), used)) = { 0 };
 #endif
@@ -140,11 +151,6 @@ int widechar_main(int argc, wchar_t **argv) {
 
 	setlocale(LC_CTYPE, "");
 
-#ifndef TOOLS_ENABLED
-	// Workaround to prevent LTCG (MSVC LTO) from removing "pck" section
-	const char *dummy_guard = dummy;
-#endif
-
 	char **argv_utf8 = new char *[argc];
 
 	for (int i = 0; i < argc; ++i) {

platform/windows/os_windows.cpp

@@ -686,6 +686,58 @@ MainLoop *OS_Windows::get_main_loop() const {
 	return main_loop;
 }
 
+uint64_t OS_Windows::get_embedded_pck_offset() const {
+	Ref<FileAccess> f = FileAccess::open(get_executable_path(), FileAccess::READ);
+	if (f.is_null()) {
+		return 0;
+	}
+
+	// Process header.
+	{
+		f->seek(0x3c);
+		uint32_t pe_pos = f->get_32();
+
+		f->seek(pe_pos);
+		uint32_t magic = f->get_32();
+		if (magic != 0x00004550) {
+			return 0;
+		}
+	}
+
+	int num_sections;
+	{
+		int64_t header_pos = f->get_position();
+
+		f->seek(header_pos + 2);
+		num_sections = f->get_16();
+		f->seek(header_pos + 16);
+		uint16_t opt_header_size = f->get_16();
+
+		// Skip rest of header + optional header to go to the section headers.
+		f->seek(f->get_position() + 2 + opt_header_size);
+	}
+	int64_t section_table_pos = f->get_position();
+
+	// Search for the "pck" section.
+	int64_t off = 0;
+	for (int i = 0; i < num_sections; ++i) {
+		int64_t section_header_pos = section_table_pos + i * 40;
+		f->seek(section_header_pos);
+
+		uint8_t section_name[9];
+		f->get_buffer(section_name, 8);
+		section_name[8] = '\0';
+
+		if (strcmp((char *)section_name, "pck") == 0) {
+			f->seek(section_header_pos + 20);
+			off = f->get_32();
+			break;
+		}
+	}
+
+	return off;
+}
+
 String OS_Windows::get_config_path() const {
 	// The XDG Base Directory specification technically only applies on Linux/*BSD, but it doesn't hurt to support it on Windows as well.
 	if (has_environment("XDG_CONFIG_HOME")) {

platform/windows/os_windows.h

@@ -144,6 +144,8 @@ public:
 	virtual int get_processor_count() const override;
 	virtual String get_processor_name() const override;
 
+	virtual uint64_t get_embedded_pck_offset() const override;
+
 	virtual String get_config_path() const override;
 	virtual String get_data_path() const override;
 	virtual String get_cache_path() const override;