[Lldb-commits] [lldb] r252963 - Another little stepping optimization: if any of the source step commands are running through a range
Zachary Turner via lldb-commits
lldb-commits at lists.llvm.org
Thu Nov 12 16:57:35 PST 2015
Ahh, seems it wasn't just Windows that was affected by this. Makes me feel
a little better :)
Posting the link to the buildbot failures here so that Jim can get full
logs if it helps.
http://lab.llvm.org:8011/builders/lldb-x86_64-ubuntu-14.04-cmake/builds/8391
On Thu, Nov 12, 2015 at 4:37 PM Ying Chen <chying at google.com> wrote:
> I reverted this patch for now.
> Please resubmit if you have a fix.
>
> Thanks,
> Ying
>
> On Thu, Nov 12, 2015 at 4:36 PM, Jim Ingham via lldb-commits <
> lldb-commits at lists.llvm.org> wrote:
>
>> If you can debug a failing case, and do whatever step operation got you
>> to the wrong place, then run up to that step, and do:
>>
>> (lldb) log enable -f <SOMEFILE> lldb step
>>
>> and then do the step, then send me that log plus the disassembly for the
>> function you were stepping in and the output of:
>>
>> (lldb) image dump line-table <SourceFile>
>>
>> for the source file you were stepping in.
>>
>> I should be able to see from there why we were stepping to the wrong
>> place.
>>
>> Jim
>>
>> > On Nov 12, 2015, at 4:03 PM, Zachary Turner <zturner at google.com> wrote:
>> >
>> > The error messages are always different because the error message is
>> printed by the test. I'm going to try to load up the executable for
>> TestStepNoDebug in the debugger and get a disassembly and do the step
>> >
>> > On Thu, Nov 12, 2015 at 4:01 PM Jim Ingham <jingham at apple.com> wrote:
>> > Is the line they stepped to - instead of the expected line - always
>> line 0?
>> >
>> > Jim
>> >
>> > > On Nov 12, 2015, at 3:52 PM, Zachary Turner <zturner at google.com>
>> wrote:
>> > >
>> > > Hi Jim,
>> > >
>> > > This breaks about 12 tests on Windows. The patch looks simple, but
>> this isn't really my area, is there anything I can give you to help
>> diagnose what might be wrong? The following tests fail:
>> > >
>> > > FAIL: LLDB (suite) :: Test-rdar-9974002.py (Windows zturner-win81 8
>> 6.2.9200 AMD64 Intel64 Family 6 Model 45 Stepping 7, GenuineIntel)
>> > > FAIL: LLDB (suite) :: TestDataFormatterHexCaps.py (Windows
>> zturner-win81 8 6.2.9200 AMD64 Intel64 Family 6 Model 45 Stepping 7,
>> GenuineIntel)
>> > > FAIL: LLDB (suite) :: TestDataFormatterNamedSummaries.py (Windows
>> zturner-win81 8 6.2.9200 AMD64 Intel64 Family 6 Model 45 Stepping 7,
>> GenuineIntel)
>> > > FAIL: LLDB (suite) :: TestDataFormatterPythonSynth.py (Windows
>> zturner-win81 8 6.2.9200 AMD64 Intel64 Family 6 Model 45 Stepping 7,
>> GenuineIntel)
>> > > FAIL: LLDB (suite) :: TestDataFormatterSynth.py (Windows
>> zturner-win81 8 6.2.9200 AMD64 Intel64 Family 6 Model 45 Stepping 7,
>> GenuineIntel)
>> > > FAIL: LLDB (suite) :: TestDiamond.py (Windows zturner-win81 8
>> 6.2.9200 AMD64 Intel64 Family 6 Model 45 Stepping 7, GenuineIntel)
>> > > FAIL: LLDB (suite) :: TestFormatPropagation.py (Windows zturner-win81
>> 8 6.2.9200 AMD64 Intel64 Family 6 Model 45 Stepping 7, GenuineIntel)
>> > > FAIL: LLDB (suite) :: TestFrames.py (Windows zturner-win81 8 6.2.9200
>> AMD64 Intel64 Family 6 Model 45 Stepping 7, GenuineIntel)
>> > > FAIL: LLDB (suite) :: TestInlineStepping.py (Windows zturner-win81 8
>> 6.2.9200 AMD64 Intel64 Family 6 Model 45 Stepping 7, GenuineIntel)
>> > > FAIL: LLDB (suite) :: TestSBData.py (Windows zturner-win81 8 6.2.9200
>> AMD64 Intel64 Family 6 Model 45 Stepping 7, GenuineIntel)
>> > > FAIL: LLDB (suite) :: TestStepNoDebug.py (Windows zturner-win81 8
>> 6.2.9200 AMD64 Intel64 Family 6 Model 45 Stepping 7, GenuineIntel)
>> > > FAIL: LLDB (suite) :: TestThreadJump.py (Windows zturner-win81 8
>> 6.2.9200 AMD64 Intel64 Family 6 Model 45 Stepping 7, GenuineIntel)
>> > >
>> > > And here's the error I get from one of the failing tests, although I
>> don't know how much insight it provides.
>> > >
>> > > Traceback (most recent call last):
>> > > File
>> "D:\src\llvm\tools\lldb\packages\Python\lldbsuite\test\lldbtest.py", line
>> 536, in wrapper
>> > > return func(self, *args, **kwargs)
>> > > File
>> "D:\src\llvm\tools\lldb\packages\Python\lldbsuite\test\lldbtest.py", line
>> 2228, in dwarf_test_method
>> > > return attrvalue(self)
>> > > File
>> "D:\src\llvm\tools\lldb\packages\Python\lldbsuite\test\lldbtest.py", line
>> 608, in wrapper
>> > > func(*args, **kwargs)
>> > > File
>> "D:\src\llvm\tools\lldb\packages\Python\lldbsuite\test\functionalities\step-avoids-no-debug\TestStepNoDebug.py",
>> line 41, in test_step_in_with_python
>> > > self.do_step_in_past_nodebug()
>> > > File
>> "D:\src\llvm\tools\lldb\packages\Python\lldbsuite\test\functionalities\step-avoids-no-debug\TestStepNoDebug.py",
>> line 105, in do_step_in_past_nodebug
>> > > self.hit_correct_line ("intermediate_return_value =
>> called_from_nodebug_actual(some_value)")
>> > > File
>> "D:\src\llvm\tools\lldb\packages\Python\lldbsuite\test\functionalities\step-avoids-no-debug\TestStepNoDebug.py",
>> line 57, in hit_correct_line
>> > > self.assertTrue (cur_line == target_line, "Stepped to line %d
>> instead of expected %d with pattern '%s'."%(cur_line, target_line, pattern))
>> > > AssertionError: False is not True : Stepped to line 0 instead of
>> expected 19 with pattern 'intermediate_return_value =
>> called_from_nodebug_actual(some_value)'.
>> > > Config=i686-d:\src\llvmbuild\ninja_release\bin\clang.exe
>> > > Session info generated @ Thu Nov 12 15:44:43 2015
>> > > To rerun this test, issue the following command from the 'test'
>> directory:
>> > >
>> > > If it's not obvious what the problem is, can we revert this until we
>> figure it out and then reland it?
>> > >
>> > > On Thu, Nov 12, 2015 at 2:34 PM Jim Ingham via lldb-commits <
>> lldb-commits at lists.llvm.org> wrote:
>> > > Author: jingham
>> > > Date: Thu Nov 12 16:32:09 2015
>> > > New Revision: 252963
>> > >
>> > > URL: http://llvm.org/viewvc/llvm-project?rev=252963&view=rev
>> > > Log:
>> > > Another little stepping optimization: if any of the source step
>> commands are running through a range
>> > > of addresses, and the range has no branches, instead of running to
>> the last instruction and
>> > > single-stepping over that, run to the first instruction after the end
>> of the range. If there
>> > > are no branches in the current range, then the bytes right after it
>> have to be in the current
>> > > function, and have to be instructions not data in code, so this is
>> safe. And it cuts down one
>> > > extra stepi per source range step.
>> > >
>> > > Incidentally, this also works around a bug in the llvm Intel
>> assembler where it treats the "rep"
>> > > prefix as a separate instruction from the repeated instruction. If
>> that were at the end of a
>> > > line range, then we would put a trap in place of the repeated
>> instruction, which is undefined
>> > > behavior. Current processors just ignore the repetition in this
>> case, which changes program behavior.
>> > > Since there would never be a line range break after the rep prefix,
>> always doing the range stepping
>> > > to the beginning of the new range avoids this problem.
>> > >
>> > > <rdar://problem/23461686>
>> > >
>> > > Modified:
>> > > lldb/trunk/source/Target/ThreadPlanStepRange.cpp
>> > >
>> > > Modified: lldb/trunk/source/Target/ThreadPlanStepRange.cpp
>> > > URL:
>> http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Target/ThreadPlanStepRange.cpp?rev=252963&r1=252962&r2=252963&view=diff
>> > >
>> ==============================================================================
>> > > --- lldb/trunk/source/Target/ThreadPlanStepRange.cpp (original)
>> > > +++ lldb/trunk/source/Target/ThreadPlanStepRange.cpp Thu Nov 12
>> 16:32:09 2015
>> > > @@ -390,12 +390,19 @@ ThreadPlanStepRange::SetNextBranchBreakp
>> > > if (branch_index == UINT32_MAX)
>> > > {
>> > > branch_index = instructions->GetSize() - 1;
>> > > + InstructionSP last_inst =
>> instructions->GetInstructionAtIndex(branch_index);
>> > > + size_t last_inst_size =
>> last_inst->GetOpcode().GetByteSize();
>> > > + run_to_address = last_inst->GetAddress();
>> > > + run_to_address.Slide(last_inst_size);
>> > > + }
>> > > + else if (branch_index - pc_index > 1)
>> > > + {
>> > > + run_to_address =
>> instructions->GetInstructionAtIndex(branch_index)->GetAddress();
>> > > }
>> > >
>> > > - if (branch_index - pc_index > 1)
>> > > + if (run_to_address.IsValid())
>> > > {
>> > > const bool is_internal = true;
>> > > - run_to_address =
>> instructions->GetInstructionAtIndex(branch_index)->GetAddress();
>> > > m_next_branch_bp_sp =
>> GetTarget().CreateBreakpoint(run_to_address, is_internal, false);
>> > > if (m_next_branch_bp_sp)
>> > > {
>> > >
>> > >
>> > > _______________________________________________
>> > > lldb-commits mailing list
>> > > lldb-commits at lists.llvm.org
>> > > http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
>> >
>>
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