From 0df5b4e72c7f81883ef1a64f32aff3aa512dc0bc Mon Sep 17 00:00:00 2001
From: Thatchapon Unprasert <thatchapon.unp@outlook.com>
Date: Sat, 25 Jan 2025 12:42:14 +0700
Subject: [PATCH] Add simulator version of CydiaSubstrate.tbd

---
 CydiaSubstrate.tbd  | 11 +++++++++++
 README.md           |  2 ++
 installsubstrate.sh | 23 +++++++++++++++++++++--
 3 files changed, 34 insertions(+), 2 deletions(-)
 create mode 100644 CydiaSubstrate.tbd

diff --git a/CydiaSubstrate.tbd b/CydiaSubstrate.tbd
new file mode 100644
index 0000000..9510dca
--- /dev/null
+++ b/CydiaSubstrate.tbd
@@ -0,0 +1,11 @@
+--- !tapi-tbd
+tbd-version:     4
+targets:         [ armv7-ios, armv7s-ios, arm64-ios, arm64e-ios, i386-ios-simulator, x86_64-ios-simulator, arm64-ios-simulator ]
+install-name:    '/Library/Frameworks/CydiaSubstrate.framework/CydiaSubstrate'
+exports:
+  - targets:          [ armv7-ios, armv7s-ios, arm64-ios, arm64e-ios, i386-ios-simulator, x86_64-ios-simulator, arm64-ios-simulator ]
+    symbols:          [ _MSCloseImage, _MSDebug, _MSFindAddress, _MSFindSymbol,
+                        _MSGetImageByName, _MSHookClassPair, _MSHookFunction,
+                        _MSHookMemory, _MSHookMessageEx, _MSImageAddress,
+                        _MSMapImage ]
+...
diff --git a/README.md b/README.md
index defbb5b..ec0aa59 100644
--- a/README.md
+++ b/README.md
@@ -62,6 +62,8 @@ rm -rfv /tmp/simject_cycript /tmp/simject_cycript.zip
 
 2. Note that, from the step 1, you can symlink instead of copying `CydiaSubstrate.framework` to multiple places. This is what `installsubstrate.sh` does to ease your life.
 
+3. By default, tweaks built for simulator will not use CydiaSubstrate as logos is configured to generate hooking code using only internal Objective-C runtime methods. While hooking via `%hook` works regardless of generators, hooking via `%hookf` is not supported unless you explicitly specify the logos generator to be `MobileSubstrate` (or `libhooker`) by using [%config](https://theos.dev/docs/logos-syntax). For example, if you want to use CydiaSubstrate for hooking, add `%config(generator=MobileSubstrate)` to your `Tweak.x(m)`. Lastly, to build simulator tweaks successfully, copy `CydiaSubstrate.tbd` from this project to `$THEOS/vendor/lib/CydiaSubstrate.framework` and replace the existing one. Make a backup if necessary.
+
 ### simject usage
 
 1. Place your dynamic libraries and accompanying property lists inside `/opt/simject` to load them in the iOS Simulator. Do not delete `simject.plist` and `simject.dylib`.
diff --git a/installsubstrate.sh b/installsubstrate.sh
index 1ed2c51..a41425e 100755
--- a/installsubstrate.sh
+++ b/installsubstrate.sh
@@ -13,6 +13,8 @@ then
     echo -e "This will install cycript's CydiaSubstrate\n"
     echo -e "If you only want to symlink CydiaSubstrate.framework to new iOS runtimes, you can run:\n"
     echo -e "\t./installsubstrate.sh link\n"
+    echo -e "If you are developing simulator tweaks that utilize MSHookFunction, you can install the simulator-supported version of CydiaSubstrate.tbd (tbd v4) by running:\n"
+    echo -e "\t./installsubstrate.sh theos\n"
     exit 1
 fi
 
@@ -29,9 +31,26 @@ SJ_RUNTIME_ROOT_11_BETA=/Applications/Xcode-beta.app/Contents/Developer/Platform
 SJ_PATH=/opt/simject
 SJ_FW_PATH=${SJ_PATH}/Frameworks
 mkdir -p ${SJ_FW_PATH}
-cd ${SJ_FW_PATH}
 
-if [[ $1 = "link" ]]
+if [[ $1 = "theos" ]]
+then
+    CS_FW_PATH="$THEOS/vendor/lib/CydiaSubstrate.framework"
+    if [[ ! -d $CS_FW_PATH ]]
+    then
+        echo "Error: CydiaSubstrate.framework not found in ${CS_FW_PATH}"
+        exit 1
+    fi
+    if [[ -f $CS_FW_PATH/CydiaSubstrate.tbd.bak ]]
+    then
+        echo "Notice: CydiaSubstrate.tbd has already been backed up, skipping"
+        exit 0
+    fi
+    echo "Backing up CydiaSubstrate.tbd..."
+    mv $CS_FW_PATH/CydiaSubstrate.tbd $CS_FW_PATH/CydiaSubstrate.tbd.bak
+    echo "Copying the new CydiaSubstrate.tbd to $CS_FW_PATH..."
+    cp $SELF_DIR/CydiaSubstrate.tbd $CS_FW_PATH/
+    exit 0
+elif [[ $1 = "link" ]]
 then
     if [[ ! -d CydiaSubstrate.framework ]]
     then