Use UnsafeRawPointer?; Fix num children

Author: kastiglione

lldb/source/Plugins/Language/Swift/SwiftFormatters.cpp

@@ -734,12 +734,10 @@ namespace lldb_private {
 namespace formatters {
 namespace swift {
 
-namespace {
 /// The size of Swift Tasks. Fragments are tail allocated.
 static constexpr size_t AsyncTaskSize = sizeof(::swift::AsyncTask);
 /// The offset of ChildFragment, which is the first fragment of an AsyncTask.
 static constexpr offset_t ChildFragmentOffset = AsyncTaskSize;
-} // namespace
 
 class EnumSyntheticFrontEnd : public SyntheticChildrenFrontEnd {
 public:
@@ -831,8 +829,9 @@ class TaskSyntheticFrontEnd : public SyntheticChildrenFrontEnd {
   };
 
   llvm::Expected<uint32_t> CalculateNumChildren() override {
-    // Show only the first four children address/id/enqueuePriority/children.
-    return 4;
+    // Show only the first five children
+    // address/id/enqueuePriority/parent/children.
+    return 5;
   }
 
   lldb::ValueObjectSP GetChildAtIndex(uint32_t idx) override {
@@ -882,21 +881,24 @@ class TaskSyntheticFrontEnd : public SyntheticChildrenFrontEnd {
     }
     case 3: {
       if (!m_parent_task_sp) {
-        // TypeMangling for "Swift.UnsafeRawPointer"
+        auto process_sp = m_backend.GetProcessSP();
+        if (!process_sp)
+          return {};
+
+        // TypeMangling for "Swift.Optional<Swift.UnsafeRawPointer>"
         CompilerType raw_pointer_type =
-            m_ts->GetTypeFromMangledTypename(ConstString("$sSVD"));
+            m_ts->GetTypeFromMangledTypename(ConstString("$sSVSgD"));
 
         addr_t parent_addr = 0;
         if (m_task_info.isChildTask) {
-          if (auto process_sp = m_backend.GetProcessSP()) {
-            Status status;
-            // Read ChildFragment::Parent, the first field of the ChildFragment.
-            parent_addr = process_sp->ReadPointerFromMemory(
-                m_task_ptr + ChildFragmentOffset, status);
-            if (status.Fail() || parent_addr == LLDB_INVALID_ADDRESS)
-              parent_addr = 0;
-          }
+          // Read ChildFragment::Parent, the first field of the ChildFragment.
+          Status status;
+          parent_addr = process_sp->ReadPointerFromMemory(
+              m_task_ptr + ChildFragmentOffset, status);
+          if (status.Fail() || parent_addr == LLDB_INVALID_ADDRESS)
+            parent_addr = 0;
         }
+
         addr_t value = parent_addr;
         DataExtractor data{reinterpret_cast<const void *>(&value),
                            sizeof(value), endian::InlHostByteOrder(),

lldb/test/API/lang/swift/async/formatters/task/parent/Makefile

@@ -0,0 +1,3 @@
+SWIFT_SOURCES := main.swift
+SWIFTFLAGS_EXTRAS := -parse-as-library
+include Makefile.rules

lldb/test/API/lang/swift/async/formatters/task/parent/TestSwiftSyntheticTaskParent.py

@@ -0,0 +1,35 @@
+import re
+import lldb
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+
+ADDR_PATTERN = "(0x[0-9a-f]{6,})"
+
+class TestCase(TestBase):
+
+    @skipUnlessDarwin
+    @swiftTest
+    def test(self):
+        self.build()
+        _, process, _, _ = lldbutil.run_to_name_breakpoint(self, "breakHere")
+
+        # First breakpoint hit occurrs in a root task, with no parent.
+        self.expect("task info", substrs=["parent = nil"])
+        root_task = self._extract("task info", f"address = {ADDR_PATTERN}")
+
+        # Continue to the next hit of the same breakpoint, which is called from
+        # an async let child task.
+        process.Continue()
+        parent_of_child_task = self._extract("task info", f"parent = {ADDR_PATTERN}")
+
+        # Ensure the parent of the child is the same as the root task.
+        self.assertEqual(root_task, parent_of_child_task)
+
+    def _extract(self, command: str, pattern: str) -> str:
+        ret = lldb.SBCommandReturnObject()
+        self.ci.HandleCommand(command, ret)
+        match = re.search(pattern, ret.GetOutput(), flags=re.I)
+        self.assertTrue(match)
+        return match.group(1) if match else ""

lldb/test/API/lang/swift/async/formatters/task/parent/main.swift

@@ -0,0 +1,9 @@
+func breakHere() {}
+
+@main struct Main {
+    static func main() async {
+        await breakHere()
+        async let x = breakHere()
+        await x
+    }
+}