From d9de2f7058fa410bd5edb91c4f7d70b45d98ab4a Mon Sep 17 00:00:00 2001
From: Oded Shapira <32619328+dondish@users.noreply.github.com>
Date: Thu, 23 Mar 2023 10:06:24 +0200
Subject: [PATCH] patterns/lua54: Added new Lua 5.4 bytecode pattern (#80)

* Lua 5.4 pattern

* Fixed formatting, added file to readme

---------

Co-authored-by: Nik <werwolv98@gmail.com>
---
 README.md             |   1 +
 patterns/lua54.hexpat | 135 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 136 insertions(+)
 create mode 100644 patterns/lua54.hexpat

diff --git a/README.md b/README.md
index f294792..875f871 100644
--- a/README.md
+++ b/README.md
@@ -71,6 +71,7 @@ Hex patterns, include patterns and magic files for the use with the ImHex Hex Ed
 | CCPAL | | [`patterns/ccpal.hexpat`](patterns/ccpal.hexpat) | Command and Conquer Voxel Palette |
 | PIF | `image/pif` | [`patterns/pif.hexpat`](patterns/pif.hexpat) | PIF Image Format |
 | JPEG | `image/jpeg` | [`patterns/jpeg.hexpat`](patterns/jpeg.hexpat) | JPEG Image Format |
+| Lua 5.4 | | [`patterns/lua54.hexpat`](patterns/lua54.hexpat) | Lua 5.4 bytecode |
 | DEX | | [`patterns/dex.hexpat`](patterns/dex.hexpat) | Dalvik EXecutable Format |
 | DS_Store | `application/octet-stream` | [`patterns/dsstore.hexpat`](patterns/dsstore.hexpat) | .DS_Store file format |
 
diff --git a/patterns/lua54.hexpat b/patterns/lua54.hexpat
new file mode 100644
index 0000000..1c29781
--- /dev/null
+++ b/patterns/lua54.hexpat
@@ -0,0 +1,135 @@
+#include <std/io.pat>
+#include <std/mem.pat>
+
+namespace impl {
+
+    fn transform_Size_array(auto array) {
+        u128 res = 0;
+        for(u8 i = 0, (array[i] & 0x80 == 0) && (i < 9), i+=1) {
+            res <<= 7;
+            res |= array[i] & 0x7f;
+        }
+        res <<= 7;
+        res |= array[sizeof(array)-1] & 0x7f;
+        return res;
+    };
+    
+    fn format_Size(auto leb128) {
+        u128 res = impl::transform_Size_array(leb128.array);
+        return std::format("{} ({:#x})", res, res);
+    };
+
+    fn transform_Size(auto leb128) {
+        return impl::transform_Size_array(leb128.array);
+    };
+    
+    fn format_LuaString(auto string) {
+       if (string.size == 0) {
+           return "None";
+        }
+        return std::format("\"{}\"", string.data);
+    };
+    
+    fn format_Constant(auto const) {
+       return const.data;
+    };
+    
+    fn format_Version(auto ver) {
+       return std::format("Ver. {}.{}", ver.major, ver.minor);
+    };
+}
+
+
+using LuaFunction;
+
+struct Size {
+        u8 array[while(addressof(this) == $ || ((addressof(this)-$ < 9) && (std::mem::read_unsigned($-1, 1) & 0x80 == 0)))] [[hidden]];
+} [[sealed, format("impl::format_Size"), transform("impl::transform_Size")]];
+    
+
+bitfield Version {
+    minor : 4;
+    major : 4;
+} [[format("impl::format_Version")]];
+
+struct LuaBinaryHeader {
+    u32 magic;
+    Version version_number;
+    u8 format_version;
+    u8 error_detection_data[6];
+    u8 size_of_int;
+    u8 size_of_size_t;
+    u8 size_of_number;
+    u64 luac_int;
+    double luac_num;
+};
+struct LuaString {
+    Size size;
+    if (size > 0) {
+        char data[size-1];
+    }
+}[[format("impl::format_LuaString")]];
+
+struct LuaConstant {
+    u8 type;
+    if (type == 3) {
+        u64 data;
+    } else if (type == 0x13) {
+        double data;
+    } else if (type == 0x4 || type == 0x14) {
+        LuaString data;
+    }
+}[[format("impl::format_Constant")]];
+
+struct LuaUpvalue {
+    u8 instack;
+    u8 idx;
+    u8 kind;
+};
+
+struct Vector<T> {
+    Size size;
+    T values[size];
+};
+
+
+struct AbsLineInfo {
+    Size pc;
+    Size line;
+};
+
+struct LocalVar {
+    LuaString varname;
+    Size startpc;
+    Size endpc;
+};
+
+struct LuaDebugInfo {
+    Vector<s8> lineInfo;
+    Vector<AbsLineInfo> abslineinfo;
+    Vector<LocalVar> local_vars;
+    Vector<LuaString> upvalues;
+};
+
+struct LuaFunction {
+    LuaString source;
+    Size line_defined;
+    Size last_line_defined;
+    u8 number_of_parameters;
+    u8 is_vararg;
+    u8 maxstacksize;
+    Vector<u32> code;
+    Vector<LuaConstant> constants;
+    Vector<LuaUpvalue> upvalues;
+    Vector<LuaFunction> protos;
+    LuaDebugInfo debugInfo;
+
+};
+
+struct LuaFile {
+    LuaBinaryHeader header;
+    u8 size_of_upvalues;
+    LuaFunction func;
+};
+
+LuaFile file @ 0;
\ No newline at end of file