[lldb-dev] lldb problems on linux
Kal Conley
kcconley at gmail.com
Thu Aug 8 08:10:21 PDT 2013
I am not able to post the source/binary of this inferior. I built it with
clang-3.4. If I build with g++4.7 lldb loads the source information
correctly, so this may be a clang bug if you think the generated dwarf info
is wrong. On the other hand gdb does handle this binary without a problem.
-Kal
2013/8/8 Malea, Daniel <daniel.malea at intel.com>
> Hmm, what compiler/version are you using to build the inferior you are
> trying to debug? Any chance you can file a bug at llvm.org/bugs and
> attach the problematic binary?
>
> Thanks,
> Dan
>
> From: Kal Conley <kcconley at gmail.com>
> Date: Thursday, 8 August, 2013 8:03 AM
> To: Andrew Kaylor <andrew.kaylor at intel.com>
> Cc: "lldb-dev at cs.uiuc.edu" <lldb-dev at cs.uiuc.edu>, Daniel Malea <
> daniel.malea at intel.com>
>
> Subject: Re: [lldb-dev] lldb problems on linux
>
> If I apply the following to ignore .debug_aranges source debugging
> works again:
>
> Index: source/Plugins/SymbolFile/DWARF/DWARFDebugInfo.cpp
> ===================================================================
> --- source/Plugins/SymbolFile/DWARF/DWARFDebugInfo.cpp (Revision 187863)
> +++ source/Plugins/SymbolFile/DWARF/DWARFDebugInfo.cpp (Arbeitskopie)
> @@ -58,7 +58,7 @@
>
> m_cu_aranges_ap.reset (new DWARFDebugAranges());
> const DataExtractor &debug_aranges_data =
> m_dwarf2Data->get_debug_aranges_data();
> - if (debug_aranges_data.GetByteSize() > 0)
> + if (0 && debug_aranges_data.GetByteSize() > 0)
> {
> if (log)
> log->Printf ("DWARFDebugInfo::GetCompileUnitAranges() for
> \"%s\" from .debug_aranges",
>
>
>
> 2013/8/8 Kal Conley <kcconley at gmail.com>
>
>> I enabled logging... I am seeing this when I run
>> (lldb) b main.cc:14
>>
>> <... Lots of other info ...>
>> main-thread Address Line Column File ISA Flags
>> main-thread ------------------ ------ ------ ------ --- -------------
>> main-thread 0x00000000004afa70 8 0 1 0 is_stmt
>> main-thread 0x00000000004afd2e 14 0 1 0 is_stmt
>> prologue_end
>> main-thread 0x00000000004afd69 16 0 1 0 is_stmt
>> main-thread 0x00000000004afd94 20 0 1 0 is_stmt
>> main-thread 0x00000000004afda3 23 0 1 0 is_stmt
>> main-thread 0x00000000004afe6c 24 0 1 0 is_stmt
>> main-thread 0x00000000004b017b 24 0 1 0 is_stmt
>> end_sequence
>> main-thread 0x00000000004b0180 2292 0 2 0 is_stmt
>> main-thread 0x00000000004b02b3 2292 0 2 0 is_stmt
>> prologue_end
>> main-thread 0x00000000004b0322 2292 0 2 0 is_stmt
>> end_sequence
>> main-thread 0x00000000004b0330 494 0 78 0 is_stmt
>> main-thread 0x00000000004b0409 494 0 78 0 is_stmt
>> prologue_end
>> main-thread 0x00000000004b04a1 494 0 78 0 is_stmt
>> end_sequence
>> main-thread 0x00000000004b04b0 2292 0 2 0 is_stmt
>> main-thread 0x00000000004b05e3 2292 0 2 0 is_stmt
>> prologue_end
>> main-thmain-thread DWARFDebugInfo::GetCompileUnitAranges() for
>> "/home/kal/test/test" from .debug_aranges
>> main-thread DWARFDebugAranges::Sort(minimize = 1) with 23 entriesread
>> 0x00000000004b0671 2292 0 2 0 is_stmt end_sequence
>> main-thread DWARFDebugAranges::Sort() 11 entries after minimizing (12
>> entries combined for 192 bytes saved)
>> main-thread 0x00000000: [0x45d670 - 0x45d7a4)
>> main-thread 0x00021392: [0x45d7b0 - 0x45d7be)
>> main-thread 0x00000000: [0x45dbf0 - 0x465c0c)
>> main-thread 0x0001d8d4: [0x465c10 - 0x467120)
>> main-thread 0x00021392: [0x467120 - 0x468172)
>> main-thread 0x0002429a: [0x468180 - 0x485d9c)
>> main-thread 0x0005cd35: [0x485da0 - 0x485e1f)
>> main-thread 0x0005dd15: [0x485e20 - 0x4865e5)
>> main-thread 0x0005fff2: [0x4865f0 - 0x486b7c)
>> main-thread 0x00061b4e: [0x486b80 - 0x487eff)
>> main-thread 0x00064a9d: [0x487f00 - 0x488295)
>> Breakpoint 1: no locations (pending).
>> WARNING: Unable to resolve breakpoint to any actual locations.
>>
>> The address 0x00000000004afd2e for line 14 is correct. If i run "b
>> main" I also get there. But that address isn't in the Aranges list.
>> -Kal
>>
>>
>> 2013/8/7 Kaylor, Andrew <andrew.kaylor at intel.com>
>>
>> I agree that logging is the best place to start. Without a better
>>> idea of what’s failing, it’s hard to say where to start.****
>>>
>>> ** **
>>>
>>> You could try something like setting a breakpoint in the
>>> CommandObjectBreakpointSet::DoExecute() function, and stepping through from
>>> there. I think that’s likely to get you to the beginning of the DWARF
>>> processing if setting a breakpoint is the first thing you do after creating
>>> the target (or specifying it on the command line). It’s a long and winding
>>> road from there to the meaty bits, but without some hints from the log
>>> output it’s hard to say where a wrong turn might have been taken.****
>>>
>>> ** **
>>>
>>> SymbolFileDWARF::ParseCompileUnit() is another potentially interesting
>>> starting place, but I think there’s a good chance you won’t get there if
>>> you aren’t seeing any source information.****
>>>
>>> ** **
>>>
>>> -Andy****
>>>
>>> ** **
>>>
>>> *From:* Malea, Daniel
>>> *Sent:* Wednesday, August 07, 2013 1:14 PM
>>> *To:* Kal Conley
>>> *Cc:* Kaylor, Andrew; lldb-dev at cs.uiuc.edu
>>>
>>> *Subject:* Re: [lldb-dev] lldb problems on linux****
>>>
>>> ** **
>>>
>>> Enabling logging is probably a good first place to start. If you're not
>>> seeing source information, then maybe lldb is unable to parse some stuff
>>> that clang is generating… to see what the DWARF parser is doing, you can:
>>> ****
>>>
>>> ** **
>>>
>>> (lldb) log enable dwarf all****
>>>
>>> ** **
>>>
>>> There's many logging categories that can be enabled; some are quite
>>> verbose..to see all of them, do:****
>>>
>>> ** **
>>>
>>> (lldb) log list****
>>>
>>> ** **
>>>
>>> Also, with the '-f' option, you can dump the output to a file for easier
>>> perusal.****
>>>
>>> ** **
>>>
>>> ** **
>>>
>>> Cheers,****
>>>
>>> Dan****
>>>
>>> ** **
>>>
>>> *From: *Kal Conley <kcconley at gmail.com>
>>> *Date: *Wednesday, 7 August, 2013 2:44 PM
>>> *To: *Daniel Malea <daniel.malea at intel.com>
>>> *Cc: *Andrew Kaylor <andrew.kaylor at intel.com>, "lldb-dev at cs.uiuc.edu" <
>>> lldb-dev at cs.uiuc.edu>
>>> *Subject: *Re: [lldb-dev] lldb problems on linux****
>>>
>>> ** **
>>>
>>> I am still seeing issues with source-level debugging. "target modules
>>> dump sections" has symbol entries. Also source level debugging is working
>>> in gdb, so I know that symbols are available.
>>> The strange thing is, I tried the same thing with a simple "Hello world"
>>> program and source level debugging worked. Both programs are being compiled
>>> with clang-3.4.
>>>
>>> Can someone give me a tip where I can should put breakpoints in LLDB to
>>> debug this?
>>>
>>> Thanks,
>>> -Kal
>>>
>>> Am 8/7/13 12:04 AM, schrieb Kal Conley:****
>>>
>>> Hi Dan,
>>> Sorry I wasn't clear. My fix fixes the test suite issue. The only
>>> remaining issue is the source debugging issue. I haven't got to look into
>>> that yet. I am on Debian Wheezy.
>>> -Kal
>>>
>>> Am 8/6/13 11:44 PM, schrieb Malea, Daniel:****
>>>
>>> Thank you Kal for the fix! Much appreciated :)****
>>>
>>> ** **
>>>
>>> I committed it in r187818.****
>>>
>>> ** **
>>>
>>> So, just to clarify, you're still unable to run the test suite after the
>>> fix? Which distro are you on?****
>>>
>>> ** **
>>>
>>> ** **
>>>
>>> Thanks,****
>>>
>>> Dan****
>>>
>>> ** **
>>>
>>> *From: *Kal Conley <kcconley at gmail.com>
>>> *Date: *Tuesday, 6 August, 2013 5:27 PM
>>> *To: *Andrew Kaylor <andrew.kaylor at intel.com>, "lldb-dev at cs.uiuc.edu" <
>>> lldb-dev at cs.uiuc.edu>
>>> *Subject: *Re: [lldb-dev] lldb problems on linux****
>>>
>>> ** **
>>>
>>> Hi Andy,
>>> So I figured out the python issue. Host::GetLLDBPath() is broken. It was
>>> failing for me because I am building in Release mode. It only works in
>>> Debug mode by luck :) The problem is lines 1035+ in
>>> source/Host/common/Host.cpp. llvm::Twine should only be used for temporary
>>> objects! See http://llvm.org/docs/ProgrammersManual.html#dss-twine
>>>
>>> I have attached a patch this fixes the issue. I haven't found time to
>>> investigate my other issue yet.
>>>
>>> Thanks!
>>> -Kal
>>>
>>> Am 8/6/13 4:29 PM, schrieb Kaylor, Andrew:****
>>>
>>> Hmm… I’ve never seen the -P option print the wrong path. Looking at
>>> the code (in Host::GetLLDBPath) it doesn’t even look possible for it to
>>> print what you’re seeing.****
>>>
>>> ****
>>>
>>> On the other hand, the second directory you mention should be the
>>> correct one. If you set PYTHONPATH to that does “python -c ‘import lldb’”
>>> work?****
>>>
>>> ****
>>>
>>> -Andy****
>>>
>>> ****
>>>
>>> *From:* Kal Conley [mailto:kcconley at gmail.com <kcconley at gmail.com>]
>>> *Sent:* Tuesday, August 06, 2013 2:00 AM
>>> *To:* Kaylor, Andrew
>>> *Cc:* lldb-dev at cs.uiuc.edu
>>> *Subject:* Re: [lldb-dev] lldb problems on linux****
>>>
>>> ****
>>>
>>> Hi Andy,
>>> I tried
>>> export PYTHONPATH=`$llvm/build/Debug+Asserts/bin/lldb -P`
>>> but it didn't work for me. If I run `build/bin/lldb -P` it outputs
>>> "build/lib7/site-packages" which doesn't exist.
>>> There is a directory build/lib/python-2.7/site-packages but if I set the
>>> PYTHONPATH to this directory I get the same errors.****
>>>
>>> I can import lldb; in python successfully though.****
>>>
>>> Any other ideas?****
>>>
>>> -Kal****
>>>
>>> ****
>>>
>>> 2013/8/5 Kaylor, Andrew <andrew.kaylor at intel.com>****
>>>
>>> Hi Kal,****
>>>
>>> ****
>>>
>>> For the second problem, you need to set the PYTHONPATH environment
>>> variable. Try this:****
>>>
>>> ****
>>>
>>> export PYTHONPATH=`$llvm/build/Debug+Asserts/bin/lldb -P`****
>>>
>>> ****
>>>
>>> Regarding the source information, I would start by using the following
>>> command within lldb (after you have created the target you want to debug):
>>> ****
>>>
>>> ****
>>>
>>> target modules dump sections****
>>>
>>> ****
>>>
>>> If you don’t see debug sections in that list, then that’s the problem.
>>> If you do, try enabling DWARF logging (‘log enable dwarf all’) and see if
>>> anything obvious turns up in the output when you try to set a breakpoint.
>>> ****
>>>
>>> ****
>>>
>>> -Andy****
>>>
>>> ****
>>>
>>> *From:* lldb-dev-bounces at cs.uiuc.edu [mailto:
>>> lldb-dev-bounces at cs.uiuc.edu] *On Behalf Of *Kal Conley
>>> *Sent:* Sunday, August 04, 2013 11:27 AM
>>> *To:* lldb-dev at cs.uiuc.edu****
>>>
>>>
>>> *Subject:* [lldb-dev] lldb problems on linux****
>>>
>>> ****
>>>
>>> Hi,****
>>>
>>> I recently build lldb from trunk (revision 187708) and source-level
>>> debugging isn't working for me. It seems its not loading any source
>>> information. What is the best way to troubleshoot this?****
>>>
>>> Also make check-lldb doesn't work on Linux when building with CMake. I
>>> just get error:
>>>
>>> This script requires lldb.py to be in either
>>> /home/user/tools/llvm_3.4~svn187708/tools/lldb/build/Debug/LLDB.framework/Resources/Python,
>>> /home/user/tools/llvm_3.4~svn187708/tools/lldb/build/Release/LLDB.framework/Resources/Python,
>>> or
>>> /home/user/tools/llvm_3.4~svn187708/tools/lldb/build/BuildAndIntegration/LLDB.framework/Resources/Python
>>> ****
>>>
>>> I get the same error with lldb-3.3.****
>>>
>>> ****
>>>
>>> Thanks!****
>>>
>>> ****
>>>
>>> ** **
>>>
>>> ** **
>>>
>>> ** **
>>>
>>
>>
>
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