Merge pull request #24086 from RandomShaper/bundle-pck-to-executable

Enhance game export

5 files changed, 212 insertions, 0 deletions

diff --git a/platform/windows/export/export.cpp b/platform/windows/export/export.cpp
index 4a72d07adc..827daa2d58 100644
--- a/platform/windows/export/export.cpp
+++ b/platform/windows/export/export.cpp
@@ -34,6 +34,8 @@
 #include "editor/editor_settings.h"
 #include "platform/windows/logo.gen.h"
 
+static Error fixup_embedded_pck(const String &p_path, int64_t p_embedded_start, int64_t p_embedded_size);
+
 class EditorExportPlatformWindows : public EditorExportPlatformPC {
 
 public:
@@ -172,6 +174,80 @@ void register_windows_exporter() {
 	platform->set_release_64("windows_64_release.exe");
 	platform->set_debug_64("windows_64_debug.exe");
 	platform->set_os_name("Windows");
+	platform->set_fixup_embedded_pck_func(&fixup_embedded_pck);
 
 	EditorExport::get_singleton()->add_export_platform(platform);
 }
+
+static Error fixup_embedded_pck(const String &p_path, int64_t p_embedded_start, int64_t p_embedded_size) {
+
+	// Patch the header of the "pck" section in the PE file so that it corresponds to the embedded data
+
+	FileAccess *f = FileAccess::open(p_path, FileAccess::READ_WRITE);
+	if (!f) {
+		return ERR_CANT_OPEN;
+	}
+
+	// Jump to the PE header and check the magic number
+	{
+		f->seek(0x3c);
+		uint32_t pe_pos = f->get_32();
+
+		f->seek(pe_pos);
+		uint32_t magic = f->get_32();
+		if (magic != 0x00004550) {
+			f->close();
+			return ERR_FILE_CORRUPT;
+		}
+	}
+
+	// Process header
+
+	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);
+	}
+
+	// Search for the "pck" section
+
+	int64_t section_table_pos = f->get_position();
+
+	bool found = false;
+	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) {
+			// "pck" section found, let's patch!
+
+			// Set virtual size to a little to avoid it taking memory (zero would give issues)
+			f->seek(section_header_pos + 8);
+			f->store_32(8);
+
+			f->seek(section_header_pos + 16);
+			f->store_32(p_embedded_size);
+			f->seek(section_header_pos + 20);
+			f->store_32(p_embedded_start);
+
+			found = true;
+			break;
+		}
+	}
+
+	f->close();
+
+	return found ? OK : ERR_FILE_CORRUPT;
+}
diff --git a/platform/windows/godot_windows.cpp b/platform/windows/godot_windows.cpp
index 0b52682c7c..11bfea6922 100644
--- a/platform/windows/godot_windows.cpp
+++ b/platform/windows/godot_windows.cpp
@@ -34,6 +34,17 @@
 #include <locale.h>
 #include <stdio.h>
 
+// For export templates, add a section; the exporter will patch it to enclose
+// the data appended to the executable (bundled PCK)
+#ifndef TOOLS_ENABLED
+#if defined _MSC_VER
+#pragma section("pck", read)
+__declspec(allocate("pck")) static char dummy[8] = { 0 };
+#elif defined __GNUC__
+static const char dummy[8] __attribute__((section("pck"), used)) = { 0 };
+#endif
+#endif
+
 PCHAR *
 CommandLineToArgvA(
 		PCHAR CmdLine,
diff --git a/platform/x11/detect.py b/platform/x11/detect.py
index 58dea615cb..f3a486df02 100644
--- a/platform/x11/detect.py
+++ b/platform/x11/detect.py
@@ -324,6 +324,9 @@ def configure(env):
 
     if env["execinfo"]:
         env.Append(LIBS=['execinfo'])
+        
+    if not env['tools']:
+        env.Append(LINKFLAGS=['-T', 'platform/x11/pck_embed.ld'])
 
     ## Cross-compilation
 
diff --git a/platform/x11/export/export.cpp b/platform/x11/export/export.cpp
index f7d98c1d68..8767aac517 100644
--- a/platform/x11/export/export.cpp
+++ b/platform/x11/export/export.cpp
@@ -30,10 +30,13 @@
 
 #include "export.h"
 
+#include "core/os/file_access.h"
 #include "editor/editor_export.h"
 #include "platform/x11/logo.gen.h"
 #include "scene/resources/texture.h"
 
+static Error fixup_embedded_pck(const String &p_path, int64_t p_embedded_start, int64_t p_embedded_size);
+
 void register_x11_exporter() {
 
 	Ref<EditorExportPlatformPC> platform;
@@ -53,6 +56,115 @@ void register_x11_exporter() {
 	platform->set_debug_64("linux_x11_64_debug");
 	platform->set_os_name("X11");
 	platform->set_chmod_flags(0755);
+	platform->set_fixup_embedded_pck_func(&fixup_embedded_pck);
 
 	EditorExport::get_singleton()->add_export_platform(platform);
 }
+
+static Error fixup_embedded_pck(const String &p_path, int64_t p_embedded_start, int64_t p_embedded_size) {
+
+	// Patch the header of the "pck" section in the ELF file so that it corresponds to the embedded data
+
+	FileAccess *f = FileAccess::open(p_path, FileAccess::READ_WRITE);
+	if (!f) {
+		return ERR_CANT_OPEN;
+	}
+
+	// Read and check ELF magic number
+	{
+		uint32_t magic = f->get_32();
+		if (magic != 0x464c457f) { // 0x7F + "ELF"
+			f->close();
+			return ERR_FILE_CORRUPT;
+		}
+	}
+
+	// Read program architecture bits from class field
+
+	int bits = f->get_8() * 32;
+
+	if (bits == 32 && p_embedded_size >= 0x100000000) {
+		f->close();
+		ERR_EXPLAIN("32-bit executables cannot have embedded data >= 4 GiB");
+		ERR_FAIL_V(ERR_INVALID_DATA);
+	}
+
+	// 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) {
+			f->close();
+			return ERR_OUT_OF_MEMORY;
+		}
+		f->get_buffer(strings, string_data_size);
+	}
+
+	// Search for the "pck" section
+
+	bool found = false;
+	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) {
+			// "pck" section found, let's patch!
+
+			if (bits == 32) {
+				f->seek(section_header_pos + 0x10);
+				f->store_32(p_embedded_start);
+				f->store_32(p_embedded_size);
+			} else { // 64
+				f->seek(section_header_pos + 0x18);
+				f->store_64(p_embedded_start);
+				f->store_64(p_embedded_size);
+			}
+
+			found = true;
+			break;
+		}
+	}
+
+	memfree(strings);
+	f->close();
+
+	return found ? OK : ERR_FILE_CORRUPT;
+}
diff --git a/platform/x11/pck_embed.ld b/platform/x11/pck_embed.ld
new file mode 100644
index 0000000000..fe09144d88
--- /dev/null
+++ b/platform/x11/pck_embed.ld
@@ -0,0 +1,10 @@
+SECTIONS
+{
+	/* Add a zero-sized section; the exporter will patch it to enclose the data appended to the executable (embedded PCK) */
+	pck 0 (NOLOAD) :
+	{
+		/* Just some content to avoid the linker discarding the section */
+		. = ALIGN(8);
+	}
+}
+INSERT AFTER .rodata;