From d8651420ccfddf84e3822f027c6f3a81ce02dbbd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ricardo=20Lu=C3=ADs=20Vaz=20Silva?= <ricolvs123@gmail.com>
Date: Tue, 1 Apr 2025 17:07:53 -0300
Subject: [PATCH] fix parameter/return checking

---
 src/common/scripting/vm/vm.h        | 16 ++++++-------
 src/common/scripting/vm/vmframe.cpp | 36 ++++++++++++++---------------
 2 files changed, 26 insertions(+), 26 deletions(-)

diff --git a/src/common/scripting/vm/vm.h b/src/common/scripting/vm/vm.h
index 727c8c3623..6f6176f280 100644
--- a/src/common/scripting/vm/vm.h
+++ b/src/common/scripting/vm/vm.h
@@ -545,7 +545,7 @@ void VMCheckParamCount(VMFunction* func, int argcount) { return VMCheckParamCoun
 // The type can't be mapped to ZScript automatically:
 
 template<typename NativeType> void VMCheckParam(VMFunction* func, int index) = delete;
-template<typename NativeType> void VMCheckReturn(VMFunction* func) = delete;
+template<typename NativeType> void VMCheckReturn(VMFunction* func, int index) = delete;
 
 // Native types we support converting to/from:
 
@@ -554,12 +554,12 @@ template<> void VMCheckParam<double>(VMFunction* func, int index);
 template<> void VMCheckParam<FString>(VMFunction* func, int index);
 template<> void VMCheckParam<DObject*>(VMFunction* func, int index);
 
-template<> void VMCheckReturn<void>(VMFunction* func);
-template<> void VMCheckReturn<int>(VMFunction* func);
-template<> void VMCheckReturn<double>(VMFunction* func);
-template<> void VMCheckReturn<FString>(VMFunction* func);
-template<> void VMCheckReturn<DObject*>(VMFunction* func);
-template<> void VMCheckReturn<void*>(VMFunction* func);
+template<> void VMCheckReturn<void>(VMFunction* func, int index);
+template<> void VMCheckReturn<int>(VMFunction* func, int index);
+template<> void VMCheckReturn<double>(VMFunction* func, int index);
+template<> void VMCheckReturn<FString>(VMFunction* func, int index);
+template<> void VMCheckReturn<DObject*>(VMFunction* func, int index);
+template<> void VMCheckReturn<void*>(VMFunction* func, int index);
 
 template<typename T>
 struct vm_decay_pointer_object
@@ -591,7 +591,7 @@ template<typename RetVal, typename... Args, size_t... I>
 void VMValidateSignatureSingle(VMFunction* func, std::index_sequence<I...>)
 {
 	VMCheckParamCount<RetVal>(func, sizeof...(Args));
-	VMCheckReturn<vm_pointer_decay<RetVal>>(func);
+	VMCheckReturn<vm_pointer_decay<RetVal>>(func, 0);
 	(VMCheckParam<vm_pointer_decay<Args>>(func, I), ...);
 }
 
diff --git a/src/common/scripting/vm/vmframe.cpp b/src/common/scripting/vm/vmframe.cpp
index e04c6f0d75..40b3dbef8c 100644
--- a/src/common/scripting/vm/vmframe.cpp
+++ b/src/common/scripting/vm/vmframe.cpp
@@ -566,53 +566,53 @@ void VMCheckParamCount(VMFunction* func, int retcount, int argcount)
 template<> void VMCheckParam<int>(VMFunction* func, int index)
 {
 	if (!func->Proto->ArgumentTypes[index]->isIntCompatible())
-		I_FatalError("%s argument %d is not an integer", func->PrintableName);
+		I_FatalError("%s argument %d is not an integer", func->PrintableName, index);
 }
 
 template<> void VMCheckParam<double>(VMFunction* func, int index)
 {
 	if (func->Proto->ArgumentTypes[index] != TypeFloat64)
-		I_FatalError("%s argument %d is not a double", func->PrintableName);
+		I_FatalError("%s argument %d is not a double", func->PrintableName, index);
 }
 
 template<> void VMCheckParam<FString>(VMFunction* func, int index)
 {
 	if (func->Proto->ArgumentTypes[index] != TypeString)
-		I_FatalError("%s argument %d is not a string", func->PrintableName);
+		I_FatalError("%s argument %d is not a string", func->PrintableName, index);
 }
 
 template<> void VMCheckParam<DObject*>(VMFunction* func, int index)
 {
-	if (func->Proto->ArgumentTypes[index]->isObjectPointer())
-		I_FatalError("%s argument %d is not an object", func->PrintableName);
+	if (!func->Proto->ArgumentTypes[index]->isObjectPointer())
+		I_FatalError("%s argument %d is not an object", func->PrintableName, index);
 }
 
-template<> void VMCheckReturn<void>(VMFunction* func)
+template<> void VMCheckReturn<void>(VMFunction* func, int index)
 {
 }
 
-template<> void VMCheckReturn<int>(VMFunction* func)
+template<> void VMCheckReturn<int>(VMFunction* func, int index)
 {
-	if (!func->Proto->ReturnTypes[0]->isIntCompatible())
-		I_FatalError("%s return value %d is not an integer", func->PrintableName);
+	if (!func->Proto->ReturnTypes[index]->isIntCompatible())
+		I_FatalError("%s return value %d is not an integer", func->PrintableName, index);
 }
 
-template<> void VMCheckReturn<double>(VMFunction* func)
+template<> void VMCheckReturn<double>(VMFunction* func, int index)
 {
-	if (func->Proto->ReturnTypes[0] != TypeFloat64)
-		I_FatalError("%s return value %d is not a double", func->PrintableName);
+	if (func->Proto->ReturnTypes[index] != TypeFloat64)
+		I_FatalError("%s return value %d is not a double", func->PrintableName, index);
 }
 
-template<> void VMCheckReturn<FString>(VMFunction* func)
+template<> void VMCheckReturn<FString>(VMFunction* func, int index)
 {
-	if (func->Proto->ReturnTypes[0] != TypeString)
-		I_FatalError("%s return value %d is not a string", func->PrintableName);
+	if (func->Proto->ReturnTypes[index] != TypeString)
+		I_FatalError("%s return value %d is not a string", func->PrintableName, index);
 }
 
-template<> void VMCheckReturn<DObject*>(VMFunction* func)
+template<> void VMCheckReturn<DObject*>(VMFunction* func, int index)
 {
-	if (func->Proto->ReturnTypes[0]->isObjectPointer())
-		I_FatalError("%s return value %d is not an object", func->PrintableName);
+	if (!func->Proto->ReturnTypes[index]->isObjectPointer())
+		I_FatalError("%s return value %d is not an object", func->PrintableName, index);
 }
 
 void VMCallCheckResult(VMFunction* func, VMValue* params, int numparams, VMReturn* results, int numresults)