use Equivalent(Optional<T>, Optional<T>)

Author: kastiglione

lldb/source/Plugins/TypeSystem/Swift/TypeSystemSwiftTypeRef.cpp

@@ -1328,7 +1328,7 @@ template <typename T> bool Equivalent(T l, T r) {
 
 /// Specialization for GetTypeInfo().
 template <> bool Equivalent<uint32_t>(uint32_t l, uint32_t r) {
-  if (l < r) {
+  if (l != r) {
     // Failure. Dump it for easier debugging.
     llvm::dbgs() << "TypeSystemSwiftTypeRef diverges from SwiftASTContext:\n";
 #define HANDLE_ENUM_CASE(VAL, CASE) \
@@ -1399,7 +1399,7 @@ template <> bool Equivalent<uint32_t>(uint32_t l, uint32_t r) {
     HANDLE_ENUM_CASE(r, eTypeIsBound);
     llvm::dbgs() << "\n";
   }
-  return l >= r;
+  return l == r;
 }
 
 /// Determine wether this demangle tree contains a sugar () node.
@@ -1508,10 +1508,9 @@ template <> bool Equivalent<ConstString>(ConstString l, ConstString r) {
   return l == r;
 }
 
-/// Version taylored to GetBitSize & friends.
-template <>
-bool Equivalent<llvm::Optional<uint64_t>>(llvm::Optional<uint64_t> l,
-                                          llvm::Optional<uint64_t> r) {
+/// Version tailored to GetBitSize & friends.
+template <typename T>
+bool Equivalent(llvm::Optional<T> l, llvm::Optional<T> r) {
   if (l == r)
     return true;
   // There are situations where SwiftASTContext incorrectly returns
@@ -1526,6 +1525,12 @@ bool Equivalent<llvm::Optional<uint64_t>>(llvm::Optional<uint64_t> l,
   return false;
 }
 
+// Introduced for `GetNumChildren`.
+template <typename T>
+bool Equivalent(llvm::Optional<T> l, T r) {
+  return Equivalent(l, llvm::Optional<T>(r));
+}
+
 } // namespace
 #endif
 
@@ -2079,10 +2084,13 @@ TypeSystemSwiftTypeRef::GetNumChildren(opaque_compiler_type_t type,
               SwiftLanguageRuntime::Get(exe_scope->CalculateProcess()))
         if (auto num_children =
                 runtime->GetNumChildren(GetCanonicalType(type), nullptr)) {
-          auto impl = [&]() -> uint32_t { return *num_children; };
-          VALIDATE_AND_RETURN(
-              impl, GetNumChildren, type,
-              (ReconstructType(type), omit_empty_base_classes, exe_ctx));
+          // Use lambda to intercept and unwrap the `Optional` return value.
+          return [&]() {
+            auto impl = [&]() { return num_children; };
+            VALIDATE_AND_RETURN(
+                impl, GetNumChildren, type,
+                (ReconstructType(type), omit_empty_base_classes, exe_ctx));
+          }().getValue();
         }
 
   LLDB_LOGF(GetLogIfAllCategoriesSet(LIBLLDB_LOG_TYPES),