Hook WinMain to perform setup and teardown actions

hook/Cargo.toml

@@ -32,3 +32,4 @@ mint_lib = { path = "../mint_lib" }
 bitflags = "2.4.1"
 widestring = "1.0.2"
 tokio = { workspace = true, features = ["full"] }
+tracing-appender = "0.2.3"

hook/src/hooks/mod.rs

@@ -18,6 +18,7 @@ use windows::Win32::System::Memory::{VirtualProtect, PAGE_EXECUTE_READWRITE};
 use crate::{
     globals,
     ue::{self, FLinearColor, UObject},
+    LOG_GUARD,
 };
 
 retour::static_detour! {
@@ -26,6 +27,8 @@ retour::static_detour! {
     static LoadGameFromSlot: unsafe extern "system" fn(*const ue::FString, i32) -> *const USaveGame;
     static DoesSaveGameExist: unsafe extern "system" fn(*const ue::FString, i32) -> bool;
     static UObjectTemperatureComponentTimerCallback: unsafe extern "system" fn(*mut c_void);
+    static WinMain: unsafe extern "system" fn(*mut (), *mut (), *mut (), i32, *const ()) -> i32;
+
 }
 
 #[repr(C)]
@@ -54,6 +57,12 @@ pub unsafe fn initialize() -> Result<()> {
     .cloned()
     .collect::<std::collections::HashMap<_, ExecFn>>();
 
+    WinMain.initialize(
+        std::mem::transmute(globals().resolution.core.as_ref().unwrap().main.0),
+        detour_main,
+    )?;
+    WinMain.enable()?;
+
     HookUFunctionBind.initialize(
         std::mem::transmute(globals().resolution.core.as_ref().unwrap().ufunction_bind.0),
         move |function| {
@@ -272,6 +281,29 @@ fn does_save_game_exist_detour(slot_name: *const ue::FString, user_index: i32) -
     }
 }
 
+fn detour_main(
+    h_instance: *mut (),
+    h_prev_instance: *mut (),
+    lp_cmd_line: *mut (),
+    n_cmd_show: i32,
+    cmd_line: *const (),
+) -> i32 {
+    let ret = unsafe {
+        WinMain.call(
+            h_instance,
+            h_prev_instance,
+            lp_cmd_line,
+            n_cmd_show,
+            cmd_line,
+        )
+    };
+
+    // about to exit, drop log guard
+    drop(unsafe { LOG_GUARD.take() });
+
+    ret
+}
+
 unsafe extern "system" fn exec_get_mod_json(
     _context: *mut ue::UObject,
     stack: *mut ue::kismet::FFrame,

hook/src/lib.rs

@@ -53,6 +53,7 @@ unsafe extern "system" fn init(_: usize) {
 }
 
 static mut GLOBALS: Option<Globals> = None;
+static mut LOG_GUARD: Option<tracing_appender::non_blocking::WorkerGuard> = None;
 
 pub struct Globals {
     resolution: hook_resolvers::HookResolution,
@@ -137,10 +138,6 @@ unsafe fn patch() -> Result<()> {
     if guard.is_none() {
         warn!("failed to set up logging");
     }
-    // Normally this guard should be held in the main scope so it's dropped on exit, but since we
-    // don't control the entrypoint we just leak it so it doesn't get dropped early. In the future
-    // the UE exit could be hooked to drop the guard there instead.
-    std::mem::forget(guard);
 
     let pak_path = bin_dir
         .and_then(Path::parent)
@@ -159,6 +156,7 @@ unsafe fn patch() -> Result<()> {
     info!("PS scan: {:#x?}", resolution);
 
     GLOBALS = Some(Globals { resolution, meta });
+    LOG_GUARD = guard;
 
     hooks::initialize()?;
 

hook_resolvers/src/lib.rs

@@ -1,6 +1,7 @@
 use patternsleuth::resolvers::futures::future::join_all;
 use patternsleuth::resolvers::unreal::blueprint_library::UFunctionBind;
 use patternsleuth::resolvers::unreal::fname::{FNameCtorWchar, FNameToString};
+use patternsleuth::resolvers::unreal::game_loop::Main;
 use patternsleuth::resolvers::unreal::gmalloc::GMalloc;
 use patternsleuth::resolvers::unreal::kismet::{FFrameStep, FFrameStepExplicitProperty};
 use patternsleuth::resolvers::unreal::save_game::{
@@ -205,6 +206,7 @@ impl_try_collector! {
     )]
     pub struct CoreResolution {
         pub gmalloc: GMalloc,
+        pub main: Main,
         pub fnametostring: FNameToString,
         pub fname_ctor_wchar: FNameCtorWchar,
         pub uobject_base_utility_get_path_name: UObjectBaseUtilityGetPathName,