lldb/test/API/python_api/value/linked_list/TestValueAPILinkedList.py

   1 """
   2 Test SBValue API linked_list_iter which treats the SBValue as a linked list and
   3 supports iteration till the end of list is reached.
   4 """
   5
   6 import lldb
   7 from lldbsuite.test.decorators import *
   8 from lldbsuite.test.lldbtest import *
   9 from lldbsuite.test import lldbutil
  10
  11
  12 class ValueAsLinkedListTestCase(TestBase):
  13     NO_DEBUG_INFO_TESTCASE = True
  14
  15     def setUp(self):
  16         # Call super's setUp().
  17         TestBase.setUp(self)
  18         # We'll use the test method name as the exe_name.
  19         self.exe_name = self.testMethodName
  20         # Find the line number to break at.
  21         self.line = line_number("main.cpp", "// Break at this line")
  22
  23     def test(self):
  24         """Exercise SBValue API linked_list_iter."""
  25         d = {"EXE": self.exe_name}
  26         self.build(dictionary=d)
  27         self.setTearDownCleanup(dictionary=d)
  28         exe = self.getBuildArtifact(self.exe_name)
  29
  30         # Create a target by the debugger.
  31         target = self.dbg.CreateTarget(exe)
  32         self.assertTrue(target, VALID_TARGET)
  33
  34         # Create the breakpoint inside function 'main'.
  35         breakpoint = target.BreakpointCreateByLocation("main.cpp", self.line)
  36         self.assertTrue(breakpoint, VALID_BREAKPOINT)
  37
  38         # Now launch the process, and do not stop at entry point.
  39         process = target.LaunchSimple(None, None, self.get_process_working_directory())
  40         self.assertTrue(process, PROCESS_IS_VALID)
  41
  42         # Get Frame #0.
  43         self.assertState(process.GetState(), lldb.eStateStopped)
  44         thread = lldbutil.get_stopped_thread(process, lldb.eStopReasonBreakpoint)
  45         self.assertTrue(
  46             thread.IsValid(),
  47             "There should be a thread stopped due to breakpoint condition",
  48         )
  49         frame0 = thread.GetFrameAtIndex(0)
  50
  51         # Get variable 'task_head'.
  52         task_head = frame0.FindVariable("task_head")
  53         self.assertTrue(task_head, VALID_VARIABLE)
  54         self.DebugSBValue(task_head)
  55
  56         # By design (see main.cpp), the visited id's are: [1, 2, 4, 5].
  57         visitedIDs = [1, 2, 4, 5]
  58         list = []
  59
  60         cvf = lldbutil.ChildVisitingFormatter(indent_child=2)
  61         for t in task_head.linked_list_iter("next"):
  62             self.assertTrue(t, VALID_VARIABLE)
  63             # Make sure that 'next' corresponds to an SBValue with pointer
  64             # type.
  65             self.assertTrue(t.TypeIsPointerType())
  66             if self.TraceOn():
  67                 print(cvf.format(t))
  68             list.append(int(t.GetChildMemberWithName("id").GetValue()))
  69
  70         # Sanity checks that the we visited all the items (no more, no less).
  71         if self.TraceOn():
  72             print("visited IDs:", list)
  73         self.assertEqual(visitedIDs, list)
  74
  75         # Let's exercise the linked_list_iter() API again, this time supplying
  76         # our end of list test function.
  77         def eol(val):
  78             """Test function to determine end of list."""
  79             # End of list is reached if either the value object is invalid
  80             # or it corresponds to a null pointer.
  81             if not val or int(val.GetValue(), 16) == 0:
  82                 return True
  83             # Also check the "id" for correct semantics.  If id <= 0, the item
  84             # is corrupted, let's return True to signify end of list.
  85             if int(val.GetChildMemberWithName("id").GetValue(), 0) <= 0:
  86                 return True
  87
  88             # Otherwise, return False.
  89             return False
  90
  91         list = []
  92         for t in task_head.linked_list_iter("next", eol):
  93             self.assertTrue(t, VALID_VARIABLE)
  94             # Make sure that 'next' corresponds to an SBValue with pointer
  95             # type.
  96             self.assertTrue(t.TypeIsPointerType())
  97             if self.TraceOn():
  98                 print(cvf.format(t))
  99             list.append(int(t.GetChildMemberWithName("id").GetValue()))
 100
 101         # Sanity checks that the we visited all the items (no more, no less).
 102         if self.TraceOn():
 103             print("visited IDs:", list)
 104         self.assertEqual(visitedIDs, list)
 105
 106         # Get variable 'empty_task_head'.
 107         empty_task_head = frame0.FindVariable("empty_task_head")
 108         self.assertTrue(empty_task_head, VALID_VARIABLE)
 109         self.DebugSBValue(empty_task_head)
 110
 111         list = []
 112         # There is no iterable item from empty_task_head.linked_list_iter().
 113         for t in empty_task_head.linked_list_iter("next", eol):
 114             if self.TraceOn():
 115                 print(cvf.format(t))
 116             list.append(int(t.GetChildMemberWithName("id").GetValue()))
 117
 118         self.assertEqual(len(list), 0)
 119
 120         # Get variable 'task_evil'.
 121         task_evil = frame0.FindVariable("task_evil")
 122         self.assertTrue(task_evil, VALID_VARIABLE)
 123         self.DebugSBValue(task_evil)
 124
 125         list = []
 126         # There 3 iterable items from task_evil.linked_list_iter(). :-)
 127         for t in task_evil.linked_list_iter("next"):
 128             if self.TraceOn():
 129                 print(cvf.format(t))
 130             list.append(int(t.GetChildMemberWithName("id").GetValue()))
 131
 132         self.assertEqual(len(list), 3)