bug fix for passing non-const reference parameters from Blueprint to …

…Lua.
liu6yang · Mar 28, 2020 · 556a5cd · 556a5cd
1 parent b6ab88f
commit 556a5cd
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Showing 2 changed files with 35 additions and 12 deletions.
diff --git a/Plugins/UnLua/Source/UnLua/Private/UEReflectionUtils.cpp b/Plugins/UnLua/Source/UnLua/Private/UEReflectionUtils.cpp
@@ -1354,19 +1354,15 @@ int32 FFunctionDesc::PostCall(lua_State *L, int32 NumParams, int32 FirstParamInd
 /**
  * Get OutParmRec for a non-const reference property
  */
-static FOutParmRec* GetNonConstOutParmRec(FOutParmRec *OutParam, UProperty *OutProperty)
+static FOutParmRec* FindOutParmRec(FOutParmRec *OutParam, UProperty *OutProperty)
 {
-    if (!OutProperty->HasAnyPropertyFlags(CPF_ConstParm))
+    while (OutParam)
     {
-        FOutParmRec *Out = OutParam;
-        while (Out)
+        if (OutParam->Property == OutProperty)
         {
-            if (Out->Property == OutProperty)
-            {
-                return Out;
-            }
-            Out = Out->NextOutParm;
+            return OutParam;
         }
+        OutParam = OutParam->NextOutParm;
     }
     return nullptr;
 }
@@ -1377,12 +1373,25 @@ static FOutParmRec* GetNonConstOutParmRec(FOutParmRec *OutParam, UProperty *OutP
 bool FFunctionDesc::CallLuaInternal(lua_State *L, void *InParams, FOutParmRec *OutParams, void *RetValueAddress) const
 {
     // prepare parameters for Lua function
+    FOutParmRec *OutParam = OutParams;
     for (const FPropertyDesc *Property : Properties)
     {
         if (Property->IsReturnParameter())
         {
             continue;
         }
+
+        if (Property->IsConstOutParameter())
+        {
+            OutParam = FindOutParmRec(OutParam, Property->GetProperty());
+            if (OutParam)
+            {
+                Property->GetValueInternal(L, OutParam->PropAddr, false);
+                OutParam = OutParam->NextOutParm;
+                continue;
+            }
+        }
+
         Property->GetValue(L, InParams, false);
     }
 
@@ -1395,11 +1404,11 @@ bool FFunctionDesc::CallLuaInternal(lua_State *L, void *InParams, FOutParmRec *O
     }
 
     int32 OutPropertyIndex = -NumResult;
-    FOutParmRec *OutParam = OutParams;
+    OutParam = OutParams;
     for (int32 i = 0; i < OutPropertyIndices.Num(); ++i)
     {
         FPropertyDesc *OutProperty = Properties[OutPropertyIndices[i]];
-        OutParam = GetNonConstOutParmRec(OutParam, OutProperty->GetProperty());
+        OutParam = FindOutParmRec(OutParam, OutProperty->GetProperty());
         check(OutParam);
         int32 Type = lua_type(L, OutPropertyIndex);
         if (Type == LUA_TNIL)

diff --git a/Plugins/UnLua/Source/UnLua/Private/UEReflectionUtils.h b/Plugins/UnLua/Source/UnLua/Private/UEReflectionUtils.h
@@ -57,7 +57,21 @@ class FPropertyDesc : public UnLua::ITypeInterface
     FORCEINLINE bool IsValid() const  { return Property != nullptr; }
 
     /**
-     * Test if this property is an out parameter. out parameter means return parameter or non-const parameter
+     * Test if this property is a const reference parameter.
+     *
+     * @return - true if the property is a const reference parameter, false otherwise
+     */
+    FORCEINLINE bool IsConstOutParameter() const { return Property->HasAllPropertyFlags(CPF_OutParm | CPF_ConstParm); }
+
+    /**
+     * Test if this property is a non-const reference parameter.
+     *
+     * @return - true if the property is a non-const reference parameter, false otherwise
+     */
+    FORCEINLINE bool IsNonConstOutParameter() const { return Property->HasAnyPropertyFlags(CPF_OutParm) && !Property->HasAnyPropertyFlags(CPF_ConstParm); }
+
+    /**
+     * Test if this property is an out parameter. out parameter means return parameter or non-const reference parameter
      *
      * @return - true if the property is an out parameter, false otherwise
      */