Clean up

Author: mpfaff

src/debug/env.zig

@@ -30,3 +30,16 @@ pub fn dumpDoorstopPath(module: if (builtin.os.tag == .windows) std.os.windows.H
 
     logger.debug("Doorstop library path: {}", .{util.fmtString(doorstop_path)});
 }
+
+pub fn dumpStdHandle(name: []const u8, handle: ?std.os.windows.HANDLE) void {
+    var buf: [std.os.windows.PATH_MAX_WIDE]u16 = undefined;
+    if (handle) |h| {
+        const path = std.os.windows.GetFinalPathNameByHandle(h, .{}, &buf) catch |e| {
+            logger.debug("Standard {s} handle at {}, unable to determine path: {}", .{ name, util.fmtAddress(h), e });
+            return;
+        };
+        logger.debug("Standard {s} handle at {}, {s}", .{ name, util.fmtAddress(handle), std.unicode.fmtUtf16Le(path) });
+    } else {
+        logger.debug("Standard {s} handle at null", .{name});
+    }
+}

src/entrypoint.zig

@@ -40,25 +40,16 @@ pub fn entrypoint(module: if (builtin.os.tag == .windows) std.os.windows.HMODULE
     debug_env.dumpWorkingDir();
     debug_env.dumpDoorstopPath(module);
 
+    if (builtin.os.tag == .windows) {
+        root.hooks.windows.stdout_handle = std.os.windows.GetStdHandle(std.os.windows.STD_OUTPUT_HANDLE) catch null;
+        root.hooks.windows.stderr_handle = std.os.windows.GetStdHandle(std.os.windows.STD_ERROR_HANDLE) catch null;
+
+        debug_env.dumpStdHandle("output", root.hooks.windows.stdout_handle);
+        debug_env.dumpStdHandle("error", root.hooks.windows.stderr_handle);
+    }
+
     switch (builtin.os.tag) {
-        // windows
-        .windows => {
-            root.hooks.windows.stdout_handle = std.os.windows.GetStdHandle(std.os.windows.STD_OUTPUT_HANDLE) catch null;
-            root.hooks.windows.stderr_handle = std.os.windows.GetStdHandle(std.os.windows.STD_ERROR_HANDLE) catch null;
-
-            logger.debug("Standard output handle at {}", .{util.fmtAddress(root.hooks.windows.stdout_handle)});
-            logger.debug("Standard error handle at {}", .{util.fmtAddress(root.hooks.windows.stderr_handle)});
-            // char_t handle_path[MAX_PATH] = L"";
-            // GetFinalPathNameByHandle(stdout_handle, handle_path, MAX_PATH, 0);
-            // LOG("Standard output handle path: %" Ts, handle_path);
-
-            const target_module = std.os.windows.kernel32.GetModuleHandleW(std.unicode.utf8ToUtf16LeStringLiteral("UnityPlayer")) orelse blk: {
-                logger.debug("No UnityPlayer module found! Using executable as the hook target.", .{});
-                break :blk std.os.windows.kernel32.GetModuleHandleW(null).?;
-            };
-
-            root.hooks.installHooksWindows(target_module);
-        },
+        .windows => root.hooks.installHooksWindows(),
         else => root.hooks.installHooksNix(),
     }
 

src/hooks.zig

@@ -90,6 +90,8 @@ fn tryIatHookUntyped(
         logger.err("Failed to hook {s}. Error: {}", .{ msg, e });
         return;
     };
+    // Need to GetProcAddress instead of simply using the target_function address, because the target_function may be a
+    // "stub" function embedded in our DLL that invokes the real function.
     const result: *const anyopaque = std.os.windows.kernel32.GetProcAddress(target_module, target_function_name) orelse {
         const e = std.os.windows.unexpectedError(std.os.windows.GetLastError()) catch {};
         logger.err("Failed to hook {s}. Error: {}", .{ msg, e });
@@ -100,7 +102,12 @@ fn tryIatHookUntyped(
     };
 }
 
-pub fn installHooksWindows(module: std.os.windows.HMODULE) callconv(.c) void {
+pub fn installHooksWindows() void {
+    const module = std.os.windows.kernel32.GetModuleHandleW(std.unicode.utf8ToUtf16LeStringLiteral("UnityPlayer")) orelse blk: {
+        logger.debug("No UnityPlayer module found! Using executable as the hook target.", .{});
+        break :blk std.os.windows.kernel32.GetModuleHandleW(null).?;
+    };
+
     tryIatHook(module, "kernel32.dll", "GetProcAddress", &std.os.windows.kernel32.GetProcAddress, @ptrCast(&dlsym_hook), "GetProcAddress");
     tryIatHook(module, "kernel32.dll", "CloseHandle", &windows.CloseHandle, &windows.close_handle_hook, "CloseHandle");
 
@@ -118,7 +125,7 @@ fn tryPltHook(hook: *plthook.c.plthook_t, funcname: [:0]const u8, funcaddr: *any
     }
 }
 
-pub fn installHooksNix() callconv(.c) void {
+pub fn installHooksNix() void {
     const hook = plthook.openByFilename(comptime "UnityPlayer" ++ builtin.os.tag.dynamicLibSuffix()) catch |e| {
         const s: [*:0]const u8 = switch (e) {
             error.FileNotFound => "FileNotFound",