Add some utility stuff

Cargo.lock

@@ -150,6 +150,16 @@ dependencies = [
  "winapi 0.2.8",
 ]
 
+[[package]]
+name = "proc-macro-crate"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "41fdbd1df62156fbc5945f4762632564d7d038153091c3fcf1067f6aef7cff92"
+dependencies = [
+ "thiserror",
+ "toml",
+]
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.29"
@@ -181,10 +191,16 @@ dependencies = [
 ]
 
 [[package]]
-name = "skidscan"
+name = "serde"
-version = "0.1.1"
+version = "1.0.130"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "89c52ddc5d6dde2bbb702e353d78c059cbbe07f15189ead0b7ac7da49b44bacc"
+checksum = "f12d06de37cf59146fbdecab66aa99f9fe4f78722e3607577a5375d66bd0c913"
+
+[[package]]
+name = "skidscan"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "91ddb509ef676cf26d1eac42416142360a15862275770dfada57e9b150244912"
 dependencies = [
  "libc",
  "skidscan-macros",
@@ -193,10 +209,11 @@ dependencies = [
 
 [[package]]
 name = "skidscan-macros"
-version = "0.1.1"
+version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c98a622ae309bfbfe69e99bbf9e8ce23efc15817eda4bda1369bbb3eea668f83"
+checksum = "881ef2150f0e4e2a855bb661a3ecd621ab1b6aa07b34aef941d1bd37b4267e8d"
 dependencies = [
+ "proc-macro-crate",
  "syn",
 ]
 
@@ -217,6 +234,35 @@ dependencies = [
  "unicode-xid",
 ]
 
+[[package]]
+name = "thiserror"
+version = "1.0.29"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "602eca064b2d83369e2b2f34b09c70b605402801927c65c11071ac911d299b88"
+dependencies = [
+ "thiserror-impl",
+]
+
+[[package]]
+name = "thiserror-impl"
+version = "1.0.29"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bad553cc2c78e8de258400763a647e80e6d1b31ee237275d756f6836d204494c"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "toml"
+version = "0.5.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a31142970826733df8241ef35dc040ef98c679ab14d7c3e54d827099b3acecaa"
+dependencies = [
+ "serde",
+]
+
 [[package]]
 name = "typenum"
 version = "1.14.0"

gmod/src/hax.rs

@@ -1,4 +1,5 @@
 #[macro_export]
+/// Common pattern for detouring.
 macro_rules! __vtable_offset {
 	($name:ident = {
 		win64: $win64:literal,
@@ -22,7 +23,8 @@ macro_rules! __vtable_offset {
 }
 
 #[macro_export]
-macro_rules! __vtable_func {
+/// Common pattern for detouring.
+macro_rules! __gmod_func {
 	($ty:ident = extern fn($($ident:ident: $arg:ty),*) $(-> $rtn:ty)?) => {
 		#[cfg(target_pointer_width = "64")]
 		pub type $ty = extern "fastcall" fn($($ident: $arg),*) $(-> $rtn)?;
@@ -36,6 +38,7 @@ macro_rules! __vtable_func {
 }
 
 #[macro_export]
+/// Common pattern for detouring.
 macro_rules! __hook_func {
 	($ty:ident = extern fn $fn:ident($($ident:ident: $arg:ty),*) $(-> $rtn:ty)? $code:block) => {
 		#[cfg(target_pointer_width = "64")]
@@ -57,3 +60,49 @@ macro_rules! __hook_func {
 		extern "C" fn $fn($($ident: $arg),*) $(-> $rtn)? $code
 	};
 }
+
+#[macro_export]
+/// Common pattern for detouring.
+macro_rules! find_gmod_signature {
+	(($library:ident, $library_path:ident), @EXPORT = $export:literal) => {
+		$library.get($export).ok().map(|func: Symbol<'static, _>| *func)
+	};
+
+	(($library:ident, $library_path:ident), @SIG = $sig:literal) => {
+		$crate::sigscan::signature!($sig).scan_module($library_path).ok().map(|x| std::mem::transmute(x))
+	};
+
+	(($library:ident, $library_path:ident) -> {
+		win64_x86_64: [$($win64_x86_64:tt)+],
+		win32_x86_64: [$($win32_x86_64:tt)+],
+
+		linux64_x86_64: [$($linux64_x86_64:tt)+],
+		linux32_x86_64: [$($linux32_x86_64:tt)+],
+
+		win32: [$($win32:tt)+],
+		linux32: [$($linux32:tt)+],
+	}) => {{
+		let x86_64 = $crate::is_x86_64();
+		if x86_64 {
+			#[cfg(all(target_os = "windows", target_pointer_width = "64"))] {
+				$crate::find_gmod_signature!(($library, $library_path), $($win64_x86_64)+)
+			}
+			#[cfg(all(target_os = "windows", target_pointer_width = "32"))] {
+				$crate::find_gmod_signature!(($library, $library_path), $($win32_x86_64)+)
+			}
+			#[cfg(all(target_os = "linux", target_pointer_width = "64"))] {
+				$crate::find_gmod_signature!(($library, $library_path), $($linux64_x86_64)+)
+			}
+			#[cfg(all(target_os = "linux", target_pointer_width = "32"))] {
+				$crate::find_gmod_signature!(($library, $library_path), $($linux32_x86_64)+)
+			}
+		} else {
+			#[cfg(target_os = "windows")] {
+				$crate::find_gmod_signature!(($library, $library_path), $($win32)+)
+			}
+			#[cfg(target_os = "linux")] {
+				$crate::find_gmod_signature!(($library, $library_path), $($linux32)+)
+			}
+		}
+	}}
+}

gmod/src/lib.rs

@@ -15,3 +15,103 @@ pub mod msgc;
 
 /// Advanced dark magic utilities
 pub mod hax;
+
+/// Returns whether this client is running the x86-64 branch
+///
+/// Current implementation checks the LuaJIT version exported by lua_shared
+pub fn is_x86_64() -> bool {
+	lua::LUA_SHARED.x86_64
+}
+
+/// Opens & returns a shared library loaded by Garry's Mod using the raw path to the module.
+///
+/// # Example
+/// ```no_run
+/// // This would only work on Windows x86-64 branch in 64-bit mode
+/// let (engine, engine_path): (gmod::libloading::Library, &'static str) = open_library_srv!("bin/win64/engine.dll").expect("Failed to open engine.dll!");
+/// println!("Opened engine.dll from: {}", engine_path);
+/// ```
+#[macro_export]
+macro_rules! open_library_raw {
+	($($path:literal),+) => {
+		::gmod::libloading::Library::new(concat!($($path),+)).map(|lib| (lib, concat!($($path),+)))
+	}
+}
+
+/// Opens & returns a shared library loaded by Garry's Mod, in "server mode" (will prioritize _srv.so on Linux main branch)
+///
+/// Respects 32-bit/64-bit main/x86-64 branches and finds the correct library.
+///
+/// # Example
+/// ```no_run
+/// let (engine, engine_path): (gmod::libloading::Library, &'static str) = open_library_srv!("engine").expect("Failed to open engine.dll!");
+/// println!("Opened engine.dll from: {}", engine_path);
+/// ```
+#[macro_export]
+macro_rules! open_library_srv {
+	($name:literal) => {{
+		#[cfg(not(all(any(target_os = "windows", target_os = "linux"), any(target_pointer_width = "32", target_pointer_width = "64"))))] {
+			compile_error!("Unsupported platform");
+		}
+
+		#[cfg(all(target_os = "windows", target_pointer_width = "64"))] {
+			::gmod::open_library_raw!("bin/win64/", $name, ".dll")
+		}
+		#[cfg(all(target_os = "windows", target_pointer_width = "32"))] {
+			::gmod::open_library_raw!("bin/", $name, ".dll")
+			.or_else(|_| ::gmod::open_library_raw!("garrysmod/bin/", $name, ".dll"))
+		}
+
+		#[cfg(all(target_os = "linux", target_pointer_width = "64"))] {
+			::gmod::open_library_raw!("bin/linux64/", $name, ".so")
+			.or_else(|_| ::gmod::open_library_raw!("bin/linux64/lib", $name, ".so"))
+		}
+		#[cfg(all(target_os = "linux", target_pointer_width = "32"))] {
+			::gmod::open_library_raw!("bin/linux32/", $name, ".so")
+			.or_else(|_| ::gmod::open_library_raw!("bin/linux32/lib", $name, ".so"))
+			.or_else(|_| ::gmod::open_library_raw!("bin/", $name, "_srv.so"))
+			.or_else(|_| ::gmod::open_library_raw!("bin/lib", $name, "_srv.so"))
+			.or_else(|_| ::gmod::open_library_raw!("bin/", $name, ".so"))
+			.or_else(|_| ::gmod::open_library_raw!("bin/lib", $name, ".so"))
+		}
+	}};
+}
+
+/// Opens & returns a shared library loaded by Garry's Mod. You are most likely looking for `open_library_srv!`, as this will prioritize non-_srv.so libraries on Linux main branch.
+///
+/// Respects 32-bit/64-bit main/x86-64 branches and finds the correct library.
+///
+/// # Example
+/// ```no_run
+/// let (engine, engine_path): (gmod::libloading::Library, &'static str) = open_library!("engine").expect("Failed to open engine.dll!");
+/// println!("Opened engine.dll from: {}", engine_path);
+/// ```
+#[macro_export]
+macro_rules! open_library {
+	($name:literal) => {{
+		#[cfg(not(all(any(target_os = "windows", target_os = "linux"), any(target_pointer_width = "32", target_pointer_width = "64"))))] {
+			compile_error!("Unsupported platform");
+		}
+
+		#[cfg(all(target_os = "windows", target_pointer_width = "64"))] {
+			::gmod::open_library_raw!("bin/win64/", $name, ".dll")
+		}
+		#[cfg(all(target_os = "windows", target_pointer_width = "32"))] {
+			::gmod::open_library_raw!("bin/", $name, ".dll")
+			.or_else(|_| ::gmod::open_library_raw!("garrysmod/bin/", $name, ".dll"))
+		}
+
+		#[cfg(all(target_os = "linux", target_pointer_width = "64"))] {
+			::gmod::open_library_raw!("bin/linux64/", $name, ".so")
+			.or_else(|_| ::gmod::open_library_raw!("bin/linux64/lib", $name, ".so"))
+		}
+		#[cfg(all(target_os = "linux", target_pointer_width = "32"))] {
+			::gmod::open_library_raw!("bin/linux32/", $name, ".so")
+			.or_else(|_| ::gmod::open_library_raw!("bin/linux32/lib", $name, ".so"))
+			.or_else(|_| ::gmod::open_library_raw!("bin/", $name, ".so"))
+			.or_else(|_| ::gmod::open_library_raw!("bin/lib", $name, ".so"))
+			.or_else(|_| ::gmod::open_library_raw!("bin/", $name, "_srv.so"))
+			.or_else(|_| ::gmod::open_library_raw!("bin/lib", $name, "_srv.so"))
+		}
+	}};
+}

gmod/src/lua/import.rs

@@ -69,10 +69,12 @@ impl LuaError {
 }
 
 lazy_static::lazy_static! {
-	pub(super) static ref LUA_SHARED: LuaShared = LuaShared::import();
+	pub(crate) static ref LUA_SHARED: LuaShared = LuaShared::import();
 }
 
-pub(super) struct LuaShared {
+pub(crate) struct LuaShared {
+	pub x86_64: bool,
+
 	pub lual_loadfile: Symbol<'static, unsafe extern "C-unwind" fn(state: LuaState, path: LuaString) -> i32>,
 	pub lual_loadstring: Symbol<'static, unsafe extern "C-unwind" fn(state: LuaState, path: LuaString) -> i32>,
 	pub lua_getfield: Symbol<'static, unsafe extern "C-unwind" fn(state: LuaState, index: i32, k: LuaString)>,
@@ -132,6 +134,8 @@ impl LuaShared {
 			}
 
 			Self {
+				x86_64: library.get::<unsafe extern "C-unwind" fn()>(b"luaJIT_version_2_1_0_beta3\0").is_ok(),
+
 				lual_loadfile: find_symbol!("luaL_loadfile"),
 				lual_loadstring: find_symbol!("luaL_loadstring"),
 				lua_getfield: find_symbol!("lua_getfield"),