From ace7aa4acbe6c724650b9093eff1ed19bf3cd087 Mon Sep 17 00:00:00 2001
From: otavepto <153766569+otavepto@users.noreply.github.com>
Date: Wed, 3 Jan 2024 01:56:26 +0200
Subject: [PATCH] added a new debug option "ResumeByDebugger" for the Windows
 version of the client loader

---
 CHANGELOG.md                                  |  3 ++
 post_build/README.experimental_steamclient.md |  6 +++-
 .../win/ColdClientLoader.cpp                  | 29 +++++++++++++++++--
 .../win/ColdClientLoader.ini                  | 23 ++++++++-------
 4 files changed, 48 insertions(+), 13 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6a98a630..39671078 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,6 @@
+* added a new option to the Windows version of the client loader to aid in debugging.  
+the option is called `ResumeByDebugger`, and setting it to `1` will prevent the loader from  
+auto resuming the main app thread, giving you a chance to attach your debugger.  
 * make the script `generate_emu_config` generate an empty `DLC.txt` if the app has no DLCs
 * windows build: sign each file after build with a self-signed generated certificate + note in the release readme regarding false-positives
 * windows build: note in readme about Windows SDK
diff --git a/post_build/README.experimental_steamclient.md b/post_build/README.experimental_steamclient.md
index ac97ad2d..acb413c6 100644
--- a/post_build/README.experimental_steamclient.md
+++ b/post_build/README.experimental_steamclient.md
@@ -24,7 +24,11 @@ You do not need to create a `steam_interfaces.txt` file for the `steamclient` ve
    * `ExeCommandLine` additional args to pass to the exe, example: `-dx11 -windowed`  
    Optionally you can specify a different location for `steamclient(64).dll`:  
    * `SteamClientDll`: path to `steamclient.dll`, either full path or relative to this `.ini` file
-   * `SteamClientDll`: path to `steamclient(64).dll`, either full path or relative to this `.ini` file
+   * `SteamClientDll`: path to `steamclient(64).dll`, either full path or relative to this `.ini` file  
+   * For debug **build** only:
+     * `ResumeByDebugger`: setting this to `1` or 'y' or `true` will prevent the loader from calling `ResumeThread` on the main thread after spawning the .exe, and it will display a mesage with the process ID (PID) so you attach your debugger on it.  
+     Note that you have to resume the main thread from the debugger after attaching, also the entry breakpoint may not be set automatically, but you can do that manually.  
+
 
 **Note** that any arguments passed to `steamclient_loader.exe` via command line will be passed to the target `.exe`.  
 Example: `steamclient_loader.exe` `-dx11`  
diff --git a/tools/steamclient_loader/win/ColdClientLoader.cpp b/tools/steamclient_loader/win/ColdClientLoader.cpp
index 3c5b3c71..feee2a6a 100644
--- a/tools/steamclient_loader/win/ColdClientLoader.cpp
+++ b/tools/steamclient_loader/win/ColdClientLoader.cpp
@@ -10,6 +10,7 @@
 #include <memory.h>
 #include <tchar.h>
 #include <stdio.h>
+#include <string>
 
 bool IsNotRelativePathOrRemoveFileName(WCHAR* output, bool Remove)
 {
@@ -166,8 +167,32 @@ int APIENTRY wWinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance
 		return 1;
 	}
 	
-	// run and wait
-	ResumeThread(processInfo.hThread);
+	bool run_exe = true;
+#ifndef EMU_RELEASE_BUILD
+	{
+		std::wstring dbg_file(50, L'\0');
+		auto res_dbg_len = GetPrivateProfileStringW(L"Debug", L"ResumeByDebugger", L"", &dbg_file[0], dbg_file.size(), CurrentDirectory);
+		if (dbg_file[0]) {
+			dbg_file = dbg_file.substr(0, res_dbg_len);
+		} else {
+			dbg_file.clear();
+		}
+		for (auto &c : dbg_file) {
+			c = (wchar_t)std::tolower((int)c);
+		}
+		if (dbg_file == L"1" || dbg_file == L"y" || dbg_file == L"yes" || dbg_file == L"true") {
+			run_exe = false;
+			std::string msg = "Attach a debugger now to PID " + std::to_string(processInfo.dwProcessId) + " and resume its main thread";
+			MessageBoxA(NULL, msg.c_str(), "ColdClientLoader", MB_OK);
+		}
+	}
+#endif
+
+	// run
+	if (run_exe) {
+		ResumeThread(processInfo.hThread);
+	}
+	// wait
 	WaitForSingleObject(processInfo.hThread, INFINITE);
 
 	CloseHandle(processInfo.hThread);
diff --git a/tools/steamclient_loader/win/ColdClientLoader.ini b/tools/steamclient_loader/win/ColdClientLoader.ini
index bc65aa24..02d9fa5a 100644
--- a/tools/steamclient_loader/win/ColdClientLoader.ini
+++ b/tools/steamclient_loader/win/ColdClientLoader.ini
@@ -1,10 +1,13 @@
-#My own modified version of ColdClientLoader originally by Rat431
-[SteamClient]
-Exe=game.exe
-ExeRunDir=.
-ExeCommandLine=
-#IMPORTANT:
-AppId=
-
-SteamClientDll=steamclient.dll
-SteamClient64Dll=steamclient64.dll
+#My own modified version of ColdClientLoader originally by Rat431
+[SteamClient]
+Exe=game.exe
+ExeRunDir=.
+ExeCommandLine=
+#IMPORTANT:
+AppId=
+
+SteamClientDll=steamclient.dll
+SteamClient64Dll=steamclient64.dll
+
+[Debug]
+ResumeByDebugger=0