teak-llvm/lldb/packages/Python/lldbsuite/test/lang/objc/exceptions/TestObjCExceptions.py
Kuba Mracek c9e1190a27 [lldb] Retrieve currently handled Obj-C exception via __cxa_current_exception_type and add GetCurrentExceptionBacktrace SB ABI
This builds on https://reviews.llvm.org/D43884 and https://reviews.llvm.org/D43886 and extends LLDB support of Obj-C exceptions to also look for a "current exception" for a thread in the C++ exception handling runtime metadata (via call to __cxa_current_exception_type). We also construct an actual historical SBThread/ThreadSP that contains frames from the backtrace in the Obj-C exception object.

The high level goal this achieves is that when we're already crashed (because an unhandled exception occurred), we can still access the exception object and retrieve the backtrace from the throw point. In Obj-C, this is particularly useful because a catch+rethrow is very common and in those cases you currently don't have any access to the throw point backtrace.

Differential Revision: https://reviews.llvm.org/D44072

llvm-svn: 349718
2018-12-20 02:01:59 +00:00

195 lines
8.0 KiB
Python

# encoding: utf-8
"""
Test lldb Obj-C exception support.
"""
from __future__ import print_function
import lldb
from lldbsuite.test.decorators import *
from lldbsuite.test.lldbtest import *
from lldbsuite.test import lldbutil
class ObjCExceptionsTestCase(TestBase):
mydir = TestBase.compute_mydir(__file__)
@skipUnlessDarwin
def test_objc_exceptions_at_throw(self):
self.build()
target = self.dbg.CreateTarget(self.getBuildArtifact("a.out"))
self.assertTrue(target, VALID_TARGET)
launch_info = lldb.SBLaunchInfo(["a.out", "0"])
lldbutil.run_to_name_breakpoint(self, "objc_exception_throw", launch_info=launch_info)
self.expect("thread list", STOPPED_DUE_TO_BREAKPOINT,
substrs=['stopped', 'stop reason = breakpoint'])
self.expect('thread exception', substrs=[
'(NSException *) exception = ',
'name: "ThrownException" - reason: "SomeReason"',
])
lldbutil.run_to_source_breakpoint(self, "// Set break point at this line.", lldb.SBFileSpec("main.mm"), launch_info=launch_info)
self.expect("thread list", STOPPED_DUE_TO_BREAKPOINT,
substrs=['stopped', 'stop reason = breakpoint'])
target = self.dbg.GetSelectedTarget()
thread = target.GetProcess().GetSelectedThread()
frame = thread.GetSelectedFrame()
# No exception being currently thrown/caught at this point
self.assertFalse(thread.GetCurrentException().IsValid())
self.assertFalse(thread.GetCurrentExceptionBacktrace().IsValid())
self.expect(
'frame variable e1',
substrs=[
'(NSException *) e1 = ',
'name: "ExceptionName" - reason: "SomeReason"'
])
self.expect(
'frame variable --dynamic-type no-run-target *e1',
substrs=[
'(NSException) *e1 = ',
'name = ', '"ExceptionName"',
'reason = ', '"SomeReason"',
'userInfo = ', '1 key/value pair',
'reserved = ', 'nil',
])
e1 = frame.FindVariable("e1")
self.assertTrue(e1)
self.assertEqual(e1.type.name, "NSException *")
self.assertEqual(e1.GetSummary(), 'name: "ExceptionName" - reason: "SomeReason"')
self.assertEqual(e1.GetChildMemberWithName("name").description, "ExceptionName")
self.assertEqual(e1.GetChildMemberWithName("reason").description, "SomeReason")
userInfo = e1.GetChildMemberWithName("userInfo").dynamic
self.assertEqual(userInfo.summary, "1 key/value pair")
self.assertEqual(userInfo.GetChildAtIndex(0).GetChildAtIndex(0).description, "some_key")
self.assertEqual(userInfo.GetChildAtIndex(0).GetChildAtIndex(1).description, "some_value")
self.assertEqual(e1.GetChildMemberWithName("reserved").description, "<nil>")
self.expect(
'frame variable e2',
substrs=[
'(NSException *) e2 = ',
'name: "ThrownException" - reason: "SomeReason"'
])
self.expect(
'frame variable --dynamic-type no-run-target *e2',
substrs=[
'(NSException) *e2 = ',
'name = ', '"ThrownException"',
'reason = ', '"SomeReason"',
'userInfo = ', '1 key/value pair',
'reserved = ',
])
e2 = frame.FindVariable("e2")
self.assertTrue(e2)
self.assertEqual(e2.type.name, "NSException *")
self.assertEqual(e2.GetSummary(), 'name: "ThrownException" - reason: "SomeReason"')
self.assertEqual(e2.GetChildMemberWithName("name").description, "ThrownException")
self.assertEqual(e2.GetChildMemberWithName("reason").description, "SomeReason")
userInfo = e2.GetChildMemberWithName("userInfo").dynamic
self.assertEqual(userInfo.summary, "1 key/value pair")
self.assertEqual(userInfo.GetChildAtIndex(0).GetChildAtIndex(0).description, "some_key")
self.assertEqual(userInfo.GetChildAtIndex(0).GetChildAtIndex(1).description, "some_value")
reserved = e2.GetChildMemberWithName("reserved").dynamic
self.assertGreater(reserved.num_children, 0)
callStackReturnAddresses = [reserved.GetChildAtIndex(i).GetChildAtIndex(1) for i in range(0, reserved.GetNumChildren())
if reserved.GetChildAtIndex(i).GetChildAtIndex(0).description == "callStackReturnAddresses"][0].dynamic
children = [callStackReturnAddresses.GetChildAtIndex(i) for i in range(0, callStackReturnAddresses.num_children)]
pcs = [i.unsigned for i in children]
names = [target.ResolveSymbolContextForAddress(lldb.SBAddress(pc, target), lldb.eSymbolContextSymbol).GetSymbol().name for pc in pcs]
for n in ["objc_exception_throw", "foo(int)", "main"]:
self.assertTrue(n in names, "%s is in the exception backtrace (%s)" % (n, names))
@skipUnlessDarwin
def test_objc_exceptions_at_abort(self):
self.build()
target = self.dbg.CreateTarget(self.getBuildArtifact("a.out"))
self.assertTrue(target, VALID_TARGET)
self.runCmd("run 0")
# We should be stopped at pthread_kill because of an unhandled exception
self.expect("thread list",
substrs=['stopped', 'stop reason = signal SIGABRT'])
self.expect('thread exception', substrs=[
'(NSException *) exception = ',
'name: "ThrownException" - reason: "SomeReason"',
'libobjc.A.dylib`objc_exception_throw',
'a.out`foo', 'at main.mm:25',
'a.out`rethrow', 'at main.mm:36',
'a.out`main',
])
process = self.dbg.GetSelectedTarget().process
thread = process.GetSelectedThread()
# There is an exception being currently processed at this point
self.assertTrue(thread.GetCurrentException().IsValid())
self.assertTrue(thread.GetCurrentExceptionBacktrace().IsValid())
history_thread = thread.GetCurrentExceptionBacktrace()
self.assertGreaterEqual(history_thread.num_frames, 4)
for n in ["objc_exception_throw", "foo(int)", "rethrow(int)", "main"]:
self.assertEqual(len([f for f in history_thread.frames if f.GetFunctionName() == n]), 1)
self.runCmd("kill")
self.runCmd("run 1")
# We should be stopped at pthread_kill because of an unhandled exception
self.expect("thread list",
substrs=['stopped', 'stop reason = signal SIGABRT'])
self.expect('thread exception', substrs=[
'(MyCustomException *) exception = ',
'libobjc.A.dylib`objc_exception_throw',
'a.out`foo', 'at main.mm:27',
'a.out`rethrow', 'at main.mm:36',
'a.out`main',
])
process = self.dbg.GetSelectedTarget().process
thread = process.GetSelectedThread()
history_thread = thread.GetCurrentExceptionBacktrace()
self.assertGreaterEqual(history_thread.num_frames, 4)
for n in ["objc_exception_throw", "foo(int)", "rethrow(int)", "main"]:
self.assertEqual(len([f for f in history_thread.frames if f.GetFunctionName() == n]), 1)
@skipUnlessDarwin
def test_cxx_exceptions_at_abort(self):
self.build()
target = self.dbg.CreateTarget(self.getBuildArtifact("a.out"))
self.assertTrue(target, VALID_TARGET)
self.runCmd("run 2")
# We should be stopped at pthread_kill because of an unhandled exception
self.expect("thread list",
substrs=['stopped', 'stop reason = signal SIGABRT'])
self.expect('thread exception', substrs=[])
process = self.dbg.GetSelectedTarget().process
thread = process.GetSelectedThread()
# C++ exceptions are not exposed in the API (yet).
self.assertFalse(thread.GetCurrentException().IsValid())
self.assertFalse(thread.GetCurrentExceptionBacktrace().IsValid())