lldb/test/API/functionalities/conditional_break/TestConditionalBreak.py

   1 """
   2 Test conditionally break on a function and inspect its variables.
   3 """
   4
   5 import lldb
   6 from lldbsuite.test.decorators import *
   7 from lldbsuite.test.lldbtest import *
   8 from lldbsuite.test import lldbutil
   9
  10 # rdar://problem/8532131
  11 # lldb not able to digest the clang-generated debug info correctly with respect to function name
  12 #
  13 # This class currently fails for clang as well as llvm-gcc.
  14
  15
  16 class ConditionalBreakTestCase(TestBase):
  17     @add_test_categories(["pyapi"])
  18     def test_with_python(self):
  19         """Exercise some thread and frame APIs to break if c() is called by a()."""
  20         self.build()
  21         self.do_conditional_break()
  22
  23     def test_with_command(self):
  24         """Simulate a user using lldb commands to break on c() if called from a()."""
  25         self.build()
  26         self.simulate_conditional_break_by_user()
  27
  28     def do_conditional_break(self):
  29         """Exercise some thread and frame APIs to break if c() is called by a()."""
  30         exe = self.getBuildArtifact("a.out")
  31
  32         target = self.dbg.CreateTarget(exe)
  33         self.assertTrue(target, VALID_TARGET)
  34
  35         breakpoint = target.BreakpointCreateByName("c", exe)
  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
  41         self.assertTrue(process, PROCESS_IS_VALID)
  42
  43         # The stop reason of the thread should be breakpoint.
  44         self.assertState(
  45             process.GetState(), lldb.eStateStopped, STOPPED_DUE_TO_BREAKPOINT
  46         )
  47
  48         # Find the line number where a's parent frame function is c.
  49         line = line_number(
  50             "main.c", "// Find the line number where c's parent frame is a here."
  51         )
  52
  53         # Suppose we are only interested in the call scenario where c()'s
  54         # immediate caller is a() and we want to find out the value passed from
  55         # a().
  56         #
  57         # The 10 in range(10) is just an arbitrary number, which means we would
  58         # like to try for at most 10 times.
  59         for j in range(10):
  60             if self.TraceOn():
  61                 print("j is: ", j)
  62             thread = lldbutil.get_one_thread_stopped_at_breakpoint(process, breakpoint)
  63             self.assertIsNotNone(
  64                 thread, "Expected one thread to be stopped at the breakpoint"
  65             )
  66
  67             if thread.GetNumFrames() >= 2:
  68                 frame0 = thread.GetFrameAtIndex(0)
  69                 name0 = frame0.GetFunction().GetName()
  70                 frame1 = thread.GetFrameAtIndex(1)
  71                 name1 = frame1.GetFunction().GetName()
  72                 # lldbutil.print_stacktrace(thread)
  73                 self.assertEqual(name0, "c", "Break on function c()")
  74                 if name1 == "a":
  75                     # By design, we know that a() calls c() only from main.c:27.
  76                     # In reality, similar logic can be used to find out the call
  77                     # site.
  78                     self.assertEqual(
  79                         frame1.GetLineEntry().GetLine(),
  80                         line,
  81                         "Immediate caller a() at main.c:%d" % line,
  82                     )
  83
  84                     # And the local variable 'val' should have a value of (int)
  85                     # 3.
  86                     val = frame1.FindVariable("val")
  87                     self.assertEqual("int", val.GetTypeName())
  88                     self.assertEqual("3", val.GetValue())
  89                     break
  90
  91             process.Continue()
  92
  93     def simulate_conditional_break_by_user(self):
  94         """Simulate a user using lldb commands to break on c() if called from a()."""
  95
  96         # Sourcing .lldb in the current working directory, which sets the main
  97         # executable, sets the breakpoint on c(), and adds the callback for the
  98         # breakpoint such that lldb only stops when the caller of c() is a().
  99         # the "my" package that defines the date() function.
 100         if self.TraceOn():
 101             print("About to source .lldb")
 102
 103         if not self.TraceOn():
 104             self.HideStdout()
 105
 106         # Separate out the "file " + self.getBuildArtifact("a.out") command from .lldb file, for the sake of
 107         # remote testsuite.
 108         self.runCmd("file " + self.getBuildArtifact("a.out"))
 109         self.runCmd("command source .lldb")
 110
 111         self.runCmd("break list")
 112
 113         if self.TraceOn():
 114             print("About to run.")
 115         self.runCmd("run", RUN_SUCCEEDED)
 116
 117         self.runCmd("break list")
 118
 119         if self.TraceOn():
 120             print("Done running")
 121
 122         # The stop reason of the thread should be breakpoint.
 123         self.expect(
 124             "thread list",
 125             STOPPED_DUE_TO_BREAKPOINT,
 126             substrs=["stopped", "stop reason = breakpoint"],
 127         )
 128
 129         # The frame info for frame #0 points to a.out`c and its immediate caller
 130         # (frame #1) points to a.out`a.
 131
 132         self.expect("frame info", "We should stop at c()", substrs=["a.out`c"])
 133
 134         # Select our parent frame as the current frame.
 135         self.runCmd("frame select 1")
 136         self.expect(
 137             "frame info", "The immediate caller should be a()", substrs=["a.out`a"]
 138         )