[lldb] Accept optional Task address in "task info" command

Author: kastiglione

lldb/source/Plugins/LanguageRuntime/Swift/SwiftLanguageRuntime.cpp

@@ -2260,21 +2260,41 @@ class CommandObjectLanguageSwiftTaskInfo final : public CommandObjectParsed {
 public:
   CommandObjectLanguageSwiftTaskInfo(CommandInterpreter &interpreter)
       : CommandObjectParsed(interpreter, "info",
-                            "Print the Task being run on the current thread.") {
+                            "Print info about the Task being run on the "
+                            "current thread or the Task at the given address."
+                            "language swift task info [<address>]") {
+    AddSimpleArgumentList(eArgTypeAddress, eArgRepeatOptional);
   }
 
 private:
   void DoExecute(Args &command, CommandReturnObject &result) override {
-    if (!m_exe_ctx.GetThreadPtr()) {
-      result.AppendError("must be run from a running process and valid thread");
-      return;
+    addr_t task_addr = LLDB_INVALID_ADDRESS;
+    StringRef task_name = "current_task";
+
+    if (command.GetArgumentCount() == 1) {
+      StringRef addr_arg = command.GetArgumentAtIndex(0);
+      if (addr_arg.getAsInteger(0, task_addr)) {
+        result.AppendErrorWithFormatv("invalid address format: {0}", addr_arg);
+        return;
+      }
+      task_name = "task";
     }
 
-    auto task_addr_or_err =
-        GetTaskAddrFromThreadLocalStorage(m_exe_ctx.GetThreadRef());
-    if (auto error = task_addr_or_err.takeError()) {
-      result.AppendError(toString(std::move(error)));
-      return;
+    if (task_addr == LLDB_INVALID_ADDRESS) {
+      if (!m_exe_ctx.GetThreadPtr()) {
+        result.AppendError(
+            "must be run from a running process and valid thread");
+        return;
+      }
+
+      auto task_addr_or_err =
+          GetTaskAddrFromThreadLocalStorage(m_exe_ctx.GetThreadRef());
+      if (auto error = task_addr_or_err.takeError()) {
+        result.AppendError(toString(std::move(error)));
+        return;
+      }
+
+      task_addr = task_addr_or_err.get();
     }
 
     auto ts_or_err = m_exe_ctx.GetTargetRef().GetScratchTypeSystemForLanguage(
@@ -2291,12 +2311,11 @@ class CommandObjectLanguageSwiftTaskInfo final : public CommandObjectParsed {
       return;
     }
 
-    addr_t task_addr = task_addr_or_err.get();
     // TypeMangling for "Swift.UnsafeCurrentTask"
     CompilerType task_type =
         ts->GetTypeFromMangledTypename(ConstString("$sSctD"));
     auto task_sp = ValueObject::CreateValueObjectFromAddress(
-        "current_task", task_addr, m_exe_ctx, task_type, false);
+        task_name, task_addr, m_exe_ctx, task_type, false);
     if (auto synthetic_sp = task_sp->GetSyntheticValue())
       task_sp = synthetic_sp;
 

lldb/test/API/lang/swift/async/tasks/info/TestSwiftTaskInfo.py

@@ -15,7 +15,8 @@ def _tail(output):
 class TestCase(TestBase):
 
     @skipUnlessDarwin
-    def test(self):
+    def test_compare_printed_task_variable_to_task_info(self):
+        """Compare the output of a printed Task to the output of `task info`."""
         self.build()
         lldbutil.run_to_source_breakpoint(
             self, "break here", lldb.SBFileSpec("main.swift")
@@ -25,3 +26,21 @@ def test(self):
         self.runCmd("language swift task info")
         task_info_output = self.res.GetOutput()
         self.assertEqual(_tail(task_info_output), _tail(frame_variable_output))
+
+    @skipUnlessDarwin
+    def test_compare_printed_task_variable_to_task_info_with_address(self):
+        """Compare the output of a printed Task to the output of `task info <address>`."""
+        self.build()
+        _, _, thread, _ = lldbutil.run_to_source_breakpoint(
+            self, "break here", lldb.SBFileSpec("main.swift")
+        )
+
+        frame = thread.frames[0]
+        task = frame.FindVariable("task")
+        task_addr = task.GetChildMemberWithName("address").unsigned
+
+        self.runCmd("frame variable task")
+        frame_variable_output = self.res.GetOutput()
+        self.runCmd(f"language swift task info {task_addr}")
+        task_info_output = self.res.GetOutput()
+        self.assertEqual(_tail(task_info_output), _tail(frame_variable_output))