[lldb] Fix handling of addresses given to swift task commands (swiftlang#11314)

The DIL implementation of `GetValueForVariableExpressionPath` succeeds when the "variable expression path" is an integer. This code expected the old behavior, where `GetValueForVariableExpressionPath` would fail for an integer value.

The fix is to try parsing the command arg as an address first (instead of as a fallback). If the command arg does not parse as an address, then it is tried as a variable expression path.

rdar://159531040

Author: kastiglione

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

@@ -2175,27 +2175,28 @@ ThreadForLiveTaskArgument(Args &command, ExecutionContext &exe_ctx) {
 
   StringRef arg = command[0].ref();
 
-  StackFrame &frame = exe_ctx.GetFrameRef();
-  uint32_t path_options =
-      StackFrame::eExpressionPathOptionsAllowDirectIVarAccess;
-  VariableSP var_sp;
-  Status status;
-  ValueObjectSP valobj_sp = frame.GetValueForVariableExpressionPath(
-      arg, eDynamicDontRunTarget, path_options, var_sp, status);
-
   addr_t task_ptr = LLDB_INVALID_ADDRESS;
-  if (status.Success() && valobj_sp) {
-    if (auto task_obj_sp = valobj_sp->GetChildMemberWithName("_task"))
-      task_ptr = task_obj_sp->GetValueAsUnsigned(LLDB_INVALID_ADDRESS);
-    if (task_ptr == LLDB_INVALID_ADDRESS)
-      return llvm::createStringError("failed to access Task pointer");
-  } else {
-    // The argument is not a valid variable expression, try parsing it as a
-    // (task) address.
-    if (arg.getAsInteger(0, task_ptr))
+  // First try the arg as a task address.
+  bool not_addr = arg.getAsInteger(0, task_ptr);
+  if (not_addr) {
+    StackFrame &frame = exe_ctx.GetFrameRef();
+    uint32_t path_options =
+        StackFrame::eExpressionPathOptionsAllowDirectIVarAccess;
+    VariableSP var_sp;
+    Status status;
+    ValueObjectSP valobj_sp = frame.GetValueForVariableExpressionPath(
+        arg, eDynamicDontRunTarget, path_options, var_sp, status);
+    if (!status.Success())
       return status.takeError();
+
+    if (valobj_sp)
+      if (auto task_obj_sp = valobj_sp->GetChildMemberWithName("_task"))
+        task_ptr = task_obj_sp->GetValueAsUnsigned(LLDB_INVALID_ADDRESS);
   }
 
+  if (task_ptr == 0 || task_ptr == LLDB_INVALID_ADDRESS)
+    return llvm::createStringError("failed to access Task pointer");
+
   if (auto *runtime = SwiftLanguageRuntime::Get(exe_ctx.GetProcessSP()))
     if (auto reflection_ctx = runtime->GetReflectionContext()) {
       auto task_info = reflection_ctx->asyncTaskInfo(task_ptr);

lldb/test/API/lang/swift/async/tasks/TestSwiftTaskBacktrace.py

@@ -5,7 +5,6 @@
 
 class TestCase(TestBase):
 
-    @skipIf(bugnumber="rdar://159531040")
     @swiftTest
     def test_backtrace_task_variable(self):
         self.build()
@@ -14,7 +13,6 @@ def test_backtrace_task_variable(self):
         )
         self.do_backtrace("task")
 
-    @skipIf(bugnumber="rdar://159531040")
     @swiftTest
     def test_backtrace_task_address(self):
         self.build()
@@ -33,6 +31,6 @@ def do_backtrace(self, arg):
                 ".sleep(",
                 "`second() at main.swift:6",
                 "`first() at main.swift:2",
-                "`closure #1 in static Main.main() at main.swift:12:19",
+                "`closure #1 in static Main.main() at main.swift:12",
             ],
         )

lldb/test/API/lang/swift/async/tasks/TestSwiftTaskSelect.py

@@ -3,7 +3,6 @@
 from lldbsuite.test.lldbtest import TestBase
 import lldbsuite.test.lldbutil as lldbutil
 
-@skipIf(bugnumber="rdar://159531153")
 class TestCase(TestBase):
 
     @swiftTest
@@ -31,9 +30,9 @@ def do_backtrace_selected_task(self, arg):
             "thread backtrace",
             substrs=[
                 ".sleep(",
-                "`second() at main.swift:6:",
-                "`first() at main.swift:2:",
-                "`closure #1 in static Main.main() at main.swift:12:",
+                "`second() at main.swift:6",
+                "`first() at main.swift:2",
+                "`closure #1 in static Main.main() at main.swift:12",
             ],
         )