<rdar://problem/11051056>
Found a race condition when sending async packets in the ProcessGDBRemote.
A little background: GDB remote clients can only send one packet at a time. You must send a packet and wait for a response. So when we continue, we obviously can't hold up the calling thread waiting for the process to stop again, so we have an async thread in the ProcessGDBRemote whose only job is to run packets that control the inferior process. When you send a continue packet, the only packet you can send is an interrupt packet (which consists of sending a CTRL+C (or a '\x03' byte)). This then stops the inferior and we can send the async packet, and then resume the target. There was a race condition that often happened during stepping where we are doing a source level single step which consists of many instruction steps and a few runs here and there when we step into a function. So the flow looks like:
inst single step
inst single step
inst single step
inst single step
inst single step
step BP and run
inst single step
inst single step
inst single step
Now if we got an async packet while the program is running we get something like:
send --> continue
send --> interrupt
recv <-- interrupt stop reply packet
send --> async packet
recv <-- async response
send --> continue again and wait for actual stop
Problems arise when this was happening when single stepping a thread where we would get:
send --> step thread 123
send --> interrupt
send --> stop reply for thread 123 (from the step)
Now we _might_ have an extra stop reply packet from the "interrupt" which we weren't checking for and we could end up with:
send --> async packet (like memory read!)
recv <-- async response (which is the interrupt stop reply packet)
Now we have the read memroy reply sitting in our buffer and waiting to be used as the reply for the next packet...
To further complicate things, the single step should have exited the async thread since the run control is finished, but now it will continue if it was interrupted.
The fixes I checked in to two major things:
- watch for the extra stop reply if we need to
- make sure we exit from the async thread run loop when the previous run control (like the instruction level single step) is finished.
Needless to say this makes very fast stepping in Xcode much more reliable.
llvm-svn: 153629
Fixed an issue with stepping where the stack frame list could get changed out from underneath you when multiple threads start accessing frame info.
llvm-svn: 153627
with recent Clang. Clang is now stricter about
presence of complete types and about use of the
"template" keyword in C++ for template-dependent
types.
llvm-svn: 153563
indicates that the section is thread specific. Any functions the load a module
given a slide, will currently ignore any sections that are thread specific.
lldb_private::Section now has:
bool
Section::IsThreadSpecific () const
{
return m_thread_specific;
}
void
Section::SetIsThreadSpecific (bool b)
{
m_thread_specific = b;
}
The ELF plug-in has been modified to set this for the ".tdata" and the ".tbss"
sections.
Eventually we need to have each lldb_private::Thread subclass be able to
resolve a thread specific section, but for now they will just not resolve. The
code for that should be trivual to add, but the address resolving functions
will need to be changed to take a "ExecutionContext" object instead of just
a target so that thread specific sections can be resolved.
llvm-svn: 153537
1 - sections only get a valid VM size if they have SHF_ALLOC in the section flags
2 - symbol names are marked as mangled if they start with "_Z"
Also fixed the DWARF parser to correctly use the section file size when extracting the DWARF.
llvm-svn: 153496
A new setting enable-synthetic-value is provided on the target to disable this behavior.
There also is a new GetNonSyntheticValue() API call on SBValue to go back from synthetic to non-synthetic. There is no call to go from non-synthetic to synthetic.
The test suite has been changed accordingly.
Fallout from changes to type searching: an hack has to be played to make it possible to use maps that contain std::string due to the special name replacement operated by clang
Fixing a test case that was using libstdcpp instead of libc++ - caught as a consequence of said changes to type searching
llvm-svn: 153495
Fixed type lookups to "do the right thing". Prior to this fix, looking up a type using "foo::bar" would result in a type list that contains all types that had "bar" as a basename unless the symbol file was able to match fully qualified names (which our DWARF parser does not).
This fix will allow type matches to be made based on the basename and then have the types that don't match filtered out. Types by name can be fully qualified, or partially qualified with the new "bool exact_match" parameter to the Module::FindTypes() method.
This fixes some issue that we discovered with dynamic type resolution as well as improves the overall type lookups in LLDB.
llvm-svn: 153482
Patched LLVM to handle generic i386 relocations.
This avoids some sudden termination problems on
i386 where the JIT would exit() out reporting
"Invalid CPU type!"
llvm-svn: 153467
Adding a test case that checks that we do not complete types before due time. This should help us track cases similar to the cascading data formatters.
llvm-svn: 153363
We do this by delegating to two available Watchpoint Register Pairs (wvr, wcr). With
each pair handling the 4 bytes of (uint64_t)variable.
llvm-svn: 153300
parse the output from "log enable --timestamp ...." and converts it to be relative
to the first timestamp and shows the time deltas between log lines. This can also
be used as a stand along script outside of lldb:
./delta.py log.txt
llvm-svn: 153288
Fixed a performance regression when dynamic types are enable where we would ask a C++ type if it can possibly be dynamic. Previously we would force the type to complete itself and then anwwer the question definitively. Now we ask the type if it is already complete and only definitively answer the question for completed types and just say "yes" for non-complete C++ types. We also always now answer yes for Objective C classes and do not complete those types either.
llvm-svn: 153284
- Addresses with no description were given
comments, leading to useless comments like
"; , "
- Addresses weren't resolved with respect
to the correct module.
llvm-svn: 153274
that the inferior cannot execute past the watchpoint-triggering instruction.
The solution is disable the watchpoint before resuming the inferior and make it hardware single step;
when the inferior stops again due to single step, re-enable the watchpoint and disable the single step
to make the inferior able to continue again without obstacle.
rdar://problem/9667960
llvm-svn: 153273
This is the feature that allowed the user to have things like:
class Base { ... };
class Derived : public Base { ... };
and have formatters defined for Base work automatically for Derived.
This feature turned out to be too expensive since it requires completing types.
This patch takes care of removing cascading (other than typedefs chain cascading), updating the test suite accordingly, and adding required Cocoa class names to keep the AppKit formatters working
llvm-svn: 153272
them both installed with the LLVM MC version being the default. I renamed the
name of the LLVM MC disassembler plug-in to "llvm-mc" and the LLVM enhanced
disassembly plug-in to "llvm-edis" and they can both be installed for now.
To use the "llvm-edis" disassembler, you can just specify it while disassembling:
(lldb) disassemble --plugin llvm-edis --name main
(lldb) disassemble --plugin llvm-mc --name main
This will allow us to compare the output of the two disassembler and eventually
deprecate the old one when the new one is ready. But it does use the new disassembler
by default so we continue to test it on a daily basis.
llvm-svn: 153231
However, the debugserver cannot get past the instruction which triggered the watchpoint.
So a workaround is in place for the time being which disables the triggered watchpoint
before resuming.
Lots of commented out printf's remain in the source which needs to be cleaned up.
WIP rdar://problem/9667960
llvm-svn: 153228
relocations (LLVM revision 153147). Now when
we report section locations in the target process,
LLVM will apply both those relocations whose
targets are in that section and those relocations
which reside in that section and point to other
sections.
llvm-svn: 153199
Greg Clayton