clang-format & add comments

Author: hekota

clang/lib/Sema/SemaOverload.cpp

@@ -1825,29 +1825,34 @@ TryImplicitConversion(Sema &S, Expr *From, QualType ToType,
     return ICS;
   }
 
-  const Type *FromTy = FromType->getUnqualifiedDesugaredType();
-  if (S.getLangOpts().HLSL && FromTy->isHLSLAttributedResourceType()) {
-    bool CanConvert = false;
-    const Type *ToTy = ToType->getUnqualifiedDesugaredType();
-    if (ToTy->isHLSLAttributedResourceType()) {
-      auto *ToResType = cast<HLSLAttributedResourceType>(ToTy);
-      auto *FromResType = cast<HLSLAttributedResourceType>(FromTy);
-      if (S.Context.hasSameUnqualifiedType(ToResType->getWrappedType(),
-                                          FromResType->getWrappedType()) &&
-          S.Context.hasSameUnqualifiedType(ToResType->getContainedType(),
-                                          FromResType->getContainedType()) &&
-          ToResType->getAttrs() == FromResType->getAttrs())
+  if (S.getLangOpts().HLSL) {
+    // Handle conversion of the HLSL resource types.
+    const Type *FromTy = FromType->getUnqualifiedDesugaredType();
+    if (FromTy->isHLSLAttributedResourceType()) {
+      // Attributed resource types can convert to other attributed
+      // resource types with the same attributes and contained types,
+      // or to __hlsl_resource_t without any attributes.
+      bool CanConvert = false;
+      const Type *ToTy = ToType->getUnqualifiedDesugaredType();
+      if (ToTy->isHLSLAttributedResourceType()) {
+        auto *ToResType = cast<HLSLAttributedResourceType>(ToTy);
+        auto *FromResType = cast<HLSLAttributedResourceType>(FromTy);
+        if (S.Context.hasSameUnqualifiedType(ToResType->getWrappedType(),
+                                             FromResType->getWrappedType()) &&
+            S.Context.hasSameUnqualifiedType(ToResType->getContainedType(),
+                                             FromResType->getContainedType()) &&
+            ToResType->getAttrs() == FromResType->getAttrs())
+          CanConvert = true;
+      } else if (ToTy->isHLSLResourceType()) {
         CanConvert = true;
-    }
-    else if (ToTy->isHLSLResourceType()) {
-      CanConvert = true;
-    }
-    if (CanConvert) {
-      ICS.setStandard();
-      ICS.Standard.setAsIdentityConversion();
-      ICS.Standard.setFromType(FromType);
-      ICS.Standard.setAllToTypes(ToType);
-      return ICS;
+      }
+      if (CanConvert) {
+        ICS.setStandard();
+        ICS.Standard.setAsIdentityConversion();
+        ICS.Standard.setFromType(FromType);
+        ICS.Standard.setAllToTypes(ToType);
+        return ICS;
+      }
     }
   }