From a17517defcb4a2b06cd5b84bc74af557eb781151 Mon Sep 17 00:00:00 2001
From: AlexKnauth <alexander@knauth.org>
Date: Mon, 16 Oct 2023 17:34:05 -0400
Subject: [PATCH] Mac std attach Module

---
 src/game_engine/unity/mono.rs | 51 +++++++++++++++++++++++++++++++++--
 1 file changed, 49 insertions(+), 2 deletions(-)

diff --git a/src/game_engine/unity/mono.rs b/src/game_engine/unity/mono.rs
index 46358c2..1f53b75 100644
--- a/src/game_engine/unity/mono.rs
+++ b/src/game_engine/unity/mono.rs
@@ -49,10 +49,19 @@ impl Module {
     /// correct for this function to work. If you don't know the version in
     /// advance, use [`attach_auto_detect`](Self::attach_auto_detect) instead.
     pub fn attach(process: &Process, version: Version) -> Option<Self> {
-        let module = ["mono.dll", "mono-2.0-bdwgc.dll"]
+        if let Some(module) = ["mono.dll", "mono-2.0-bdwgc.dll"]
             .iter()
-            .find_map(|&name| process.get_module_address(name).ok())?;
+            .find_map(|&name| process.get_module_address(name).ok()) {
+            return Self::attach_dll(process, version, module);
+        }
+        #[cfg(feature = "std")]
+        if let Ok(module_range) = process.get_module_range("libmonobdwgc-2.0.dylib") {
+            return Self::attach_dylib(process, version, module_range);
+        }
+        None
+    }
 
+    fn attach_dll(process: &Process, version: Version, module: Address) -> Option<Self> {
         let is_64_bit = pe::MachineType::read(process, module)? == pe::MachineType::X86_64;
         let offsets = Offsets::new(version, is_64_bit, BinaryFormat::PE);
 
@@ -101,6 +110,44 @@ impl Module {
         }
     }
 
+    #[cfg(feature = "std")]
+    fn attach_dylib(process: &Process, version: Version, module_range: (Address, u64)) -> Option<Self> {
+        let is_64_bit = macho::is_64_bit(process, macho::scan_macho_page(process, module_range)?)?;
+        let offsets = Offsets::new(version, is_64_bit, BinaryFormat::MachO);
+
+        let process_path = process.get_path().ok()?;
+        let contents_path = Path::new(&process_path).parent()?.parent()?;
+        let mono_module_path = contents_path.join("Frameworks").join("libmonobdwgc-2.0.dylib");
+        let mono_module_bytes = file_read_all_bytes(mono_module_path).ok()?;
+
+        let mono_assembly_foreach_offset: u32 = macho::get_function_offset(&mono_module_bytes, b"_mono_assembly_foreach")?;
+
+        let function_array: [u8; 0x100] = macho::slice_read(&mono_module_bytes, mono_assembly_foreach_offset as usize).ok()?;
+        let sig_function_array: Signature<0x100> = Signature::Simple(function_array);
+        let mono_assembly_foreach_address = sig_function_array.scan_process_range(process, module_range)?;
+
+        let assemblies: Address = match is_64_bit {
+            true => {
+                const SIG_MONO_64_DYLIB: Signature<3> = Signature::new("48 8B 3D");
+                // RIP-relative addressing
+                // 3 is the offset to the next thing after the signature
+                let scan_address = SIG_MONO_64_DYLIB.scan_process_range(process, (mono_assembly_foreach_address, 0x100))? + 3;
+                // 4 is the offset to the next instruction after relative
+                scan_address + 0x4 + process.read::<i32>(scan_address).ok()?
+            }
+            false => {
+                return None;
+            }
+        };
+
+        Some(Self {
+            is_64_bit,
+            version,
+            offsets,
+            assemblies,
+        })
+    }
+
     fn assemblies<'a>(&'a self, process: &'a Process) -> impl Iterator<Item = Assembly> + 'a {
         let mut assembly = self.assemblies;
         let mut iter_break = assembly.is_null();