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Don't assume that stepping out of a function will land on the next line. 

For instance, some recent clang emits this code on x86_64:

    0x100002b99 <+57>: callq  0x100002b40               ; step_out_of_here at main.cpp:11
->  0x100002b9e <+62>: xorl   %eax, %eax
    0x100002ba0 <+64>: popq   %rbp
    0x100002ba1 <+65>: retq

and the "xorl %eax, %eax" is attributed to the same line as the callq.  Since
step out is supposed to stop just on returning from the function, you can't guarantee
it will end up on the next line.  I changed the test to check that we were either
on the call line or on the next line, since either would be right depending on the
debug information.
This commit is contained in:
Jim Ingham 2021-03-18 17:44:17 -07:00
parent fa26da0582
commit 71c4da83b6
2 changed files with 40 additions and 38 deletions
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76
lldb/test/API/functionalities/thread/step_out/TestThreadStepOut.py
View File

@ -62,50 +62,58 @@ class ThreadStepOutTestCase(TestBase):
"""Test thread step out on one thread via Python API (dwarf)."""
self.build(dictionary=self.getBuildFlags())
self.step_out_test(self.step_out_with_python)
def setUp(self):
# Call super's setUp().
TestBase.setUp(self)
# Find the line number for our breakpoint.
self.bkpt_string = '// Set breakpoint here'
self.breakpoint = line_number('main.cpp', self.bkpt_string)
self.step_in_line = line_number('main.cpp', '// But we might still be here')
self.step_out_dest = line_number('main.cpp', '// Expect to stop here after step-out.')
self.step_out_destination = line_number(
'main.cpp', '// Expect to stop here after step-out.')
def check_stepping_thread(self):
zeroth_frame = self.step_out_thread.frames[0]
line_entry = zeroth_frame.line_entry
self.assertTrue(line_entry.IsValid(), "Stopped at a valid line entry")
self.assertEqual("main.cpp", line_entry.file.basename, "Still in main.cpp")
# We can't really tell whether we stay on our line
# or get to the next line, it depends on whether there are any
# instructions between the call and the return.
line = line_entry.line
self.assertTrue(line == self.step_out_dest or line == self.step_in_line, "Stepped to the wrong line: {0}".format(line))
def step_out_single_thread_with_cmd(self):
other_threads = {}
for thread in self.process.threads:
if thread.GetIndexID() == self.step_out_thread.GetIndexID():
continue
other_threads[thread.GetIndexID()] = thread.frames[0].line_entry
# There should be other threads...
self.assertNotEqual(len(other_threads), 0)
self.step_out_with_cmd("this-thread")
self.expect(
"thread backtrace all",
"Thread location after step out is correct",
substrs=[
"main.cpp:%d" %
self.step_out_destination,
"main.cpp:%d" %
self.breakpoint])
# The other threads should not have made progress:
for thread in self.process.threads:
index_id = thread.GetIndexID()
line_entry = other_threads.get(index_id)
if line_entry:
self.assertEqual(thread.frames[0].line_entry.file.basename, line_entry.file.basename, "Thread {0} moved by file".format(index_id))
self.assertEqual(thread.frames[0].line_entry.line, line_entry.line, "Thread {0} moved by line".format(index_id))
def step_out_all_threads_with_cmd(self):
self.step_out_with_cmd("all-threads")
self.expect(
"thread backtrace all",
"Thread location after step out is correct",
substrs=[
"main.cpp:%d" %
self.step_out_destination])
def step_out_with_cmd(self, run_mode):
self.runCmd("thread select %d" % self.step_out_thread.GetIndexID())
self.runCmd("thread step-out -m %s" % run_mode)
self.expect("process status", "Expected stop reason to be step-out",
substrs=["stop reason = step out"])
self.expect(
"thread list",
"Selected thread did not change during step-out",
substrs=[
"* thread #%d" %
self.step_out_thread.GetIndexID()])
selected_thread = self.process.GetSelectedThread()
self.assertEqual(selected_thread.GetIndexID(), self.step_out_thread.GetIndexID(), "Step out changed selected thread.")
self.check_stepping_thread()
def step_out_with_python(self):
self.step_out_thread.StepOut()
@ -115,18 +123,12 @@ class ThreadStepOutTestCase(TestBase):
reason,
"Expected thread stop reason 'plancomplete', but got '%s'" %
lldbutil.stop_reason_to_str(reason))
# Verify location after stepping out
frame = self.step_out_thread.GetFrameAtIndex(0)
desc = lldbutil.get_description(frame.GetLineEntry())
expect = "main.cpp:%d" % self.step_out_destination
self.assertTrue(
expect in desc, "Expected %s but thread stopped at %s" %
(expect, desc))
self.check_stepping_thread()
def step_out_test(self, step_out_func):
"""Test single thread step out of a function."""
(self.inferior_target, self.inferior_process, thread, bkpt) = lldbutil.run_to_source_breakpoint(
(self.inferior_target, self.process, thread, bkpt) = lldbutil.run_to_source_breakpoint(
self, self.bkpt_string, lldb.SBFileSpec('main.cpp'), only_one_thread = False)
# We hit the breakpoint on at least one thread. If we hit it on both threads
@ -135,13 +137,13 @@ class ThreadStepOutTestCase(TestBase):
# the breakpoint:
(breakpoint_threads, other_threads) = ([], [])
lldbutil.sort_stopped_threads(self.inferior_process,
lldbutil.sort_stopped_threads(self.process,
breakpoint_threads=breakpoint_threads,
other_threads=other_threads)
if len(breakpoint_threads) == 1:
success = thread.Suspend()
self.assertTrue(success, "Couldn't suspend a thread")
bkpt_threads = lldbutil.continue_to_breakpoint(self.inferior_process,
bkpt_threads = lldbutil.continue_to_breakpoint(self.process,
bkpt)
self.assertEqual(len(bkpt_threads), 1, "Second thread stopped")
success = thread.Resume()

2
lldb/test/API/functionalities/thread/step_out/main.cpp
View File

@ -19,7 +19,7 @@ thread_func ()
pseudo_barrier_wait(g_barrier);
// Do something
step_out_of_here();
step_out_of_here(); // But we might still be here
// Return
return NULL; // Expect to stop here after step-out.