Pavel Labath 35674976f0 [lldb/Test] Introduce "assertSuccess"
Summary:
A lot of our tests do 'self.assertTrue(error.Success()'. The problem
with that is that when this fails, it produces a completely useless
error message (False is not True) and the most important piece of
information -- the actual error message -- is completely hidden.

Sometimes we mitigate that by including the error message in the "msg"
argument, but this has two additional problems:
- as the msg argument is evaluated unconditionally, one needs to be
  careful to not trigger an exception when the operation was actually
  successful.
- it requires more typing, which means we often don't do it

assertSuccess solves these problems by taking the entire SBError object
as an argument. If the operation was unsuccessful, it can format a
reasonable error message itself. The function still accepts a "msg"
argument, which can include any additional context, but this context now
does not need to include the error message.

To demonstrate usage, I replace a number of existing assertTrue
assertions with the new function. As this process is not easily
automatable, I have just manually updated a representative sample. In
some cases, I did not update the code to use assertSuccess, but I went
for even higher-level assertion apis (runCmd, expect_expr), as these are
even shorter, and can produce even better failure messages.

Reviewers: teemperor, JDevlieghere

Subscribers: arphaman, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D82759
2020-06-30 15:41:03 +02:00

79 lines
2.7 KiB
Python

"""
Tests expression evaluation in context of an objc class.
"""
import lldb
import lldbsuite.test.lldbutil as lldbutil
from lldbsuite.test.decorators import *
from lldbsuite.test.lldbtest import *
class ContextObjectObjcTestCase(TestBase):
mydir = TestBase.compute_mydir(__file__)
@skipUnlessDarwin
def test_context_object_objc(self):
"""Tests expression evaluation in context of an objc class."""
self.build()
(target, process, thread, bkpt) = lldbutil.run_to_source_breakpoint(self, '// Break here', self.main_source_spec)
frame = thread.GetFrameAtIndex(0)
#
# Test objc class variable
#
obj_val = frame.FindVariable("objcClass")
self.assertTrue(obj_val.IsValid())
obj_val = obj_val.Dereference()
self.assertTrue(obj_val.IsValid())
# Test an empty expression evaluation
value = obj_val.EvaluateExpression("")
self.assertFalse(value.IsValid())
self.assertFalse(value.GetError().Success())
# Test retrieving of a field (not a local with the same name)
value = obj_val.EvaluateExpression("field")
self.assertTrue(value.IsValid())
self.assertTrue(value.GetError().Success())
self.assertEqual(value.GetValueAsSigned(), 1111)
# Test if the self pointer is properly evaluated
# Test retrieving of an objcClass's property through the self pointer
value = obj_val.EvaluateExpression("self.property")
self.assertTrue(value.IsValid())
self.assertSuccess(value.GetError())
self.assertEqual(value.GetValueAsSigned(), 2222)
# Test objcClass's methods evaluation through the self pointer
value = obj_val.EvaluateExpression("[self method]")
self.assertTrue(value.IsValid())
self.assertSuccess(value.GetError())
self.assertEqual(value.GetValueAsSigned(), 3333)
# Test if we can use a computation result reference object correctly
obj_val = frame.EvaluateExpression("[ObjcClass createNew]")
self.assertTrue(obj_val.IsValid())
obj_val = obj_val.Dereference()
self.assertTrue(obj_val.IsValid())
# Test an expression evaluation on it
value = obj_val.EvaluateExpression("1")
self.assertTrue(value.IsValid())
self.assertSuccess(value.GetError())
# Test retrieving of a field on it
value = obj_val.EvaluateExpression("field")
self.assertTrue(value.IsValid())
self.assertSuccess(value.GetError())
self.assertEqual(value.GetValueAsSigned(), 1111)
def setUp(self):
TestBase.setUp(self)
self.main_source = "main.m"
self.main_source_spec = lldb.SBFileSpec(self.main_source)