Commit Graph

9 Commits

Author SHA1 Message Date
Greg Clayton e0d378b334 Fixed the LLDB build so that we can have private types, private enums and
public types and public enums. This was done to keep the SWIG stuff from
parsing all sorts of enums and types that weren't needed, and allows us to
abstract our API better.

llvm-svn: 128239
2011-03-24 21:19:54 +00:00
Greg Clayton e576ab2996 All UnwindPlan objects are now passed around as shared pointers.
ArchDefaultUnwindPlan plug-in interfaces are now cached per architecture 
instead of being leaked for every frame.

Split the ArchDefaultUnwindPlan_x86 into ArchDefaultUnwindPlan_x86_64 and
ArchDefaultUnwindPlan_i386 interfaces.

There were sporadic crashes that were due to something leaking or being 
destroyed when doing stack crawls. This patch should clear up these issues.

llvm-svn: 125541
2011-02-15 00:19:15 +00:00
Greg Clayton 58be07b28c Added memory caching to lldb_private::Process. All lldb_private::Process
subclasses will automatically be able to take advantage of caching. The
cache line size is set to 512 by default.

This greatly speeds up stack backtraces on MacOSX when using the 
ProcessGDBRemote process plug-in since only about 6300 packets per second
can be sent.

Initial speedups show:

Prior to caching: 10,000 stack frames took 5.2 seconds
After caching: 10,000 stack frames in 240 ms!

About a 20x speedup!

llvm-svn: 122996
2011-01-07 06:08:19 +00:00
Greg Clayton 5ccbd294b2 Fixed issues with RegisterContext classes and the subclasses. There was
an issue with the way the UnwindLLDB was handing out RegisterContexts: it
was making shared pointers to register contexts and then handing out just
the pointers (which would get put into shared pointers in the thread and
stack frame classes) and cause double free issues. MallocScribble helped to
find these issues after I did some other cleanup. To help avoid any
RegisterContext issue in the future, all code that deals with them now
returns shared pointers to the register contexts so we don't end up with
multiple deletions. Also now that the RegisterContext class doesn't require
a stack frame, we patched a memory leak where a StackFrame object was being
created and leaked.

Made the RegisterContext class not have a pointer to a StackFrame object as
one register context class can be used for N inlined stack frames so there is
not a 1 - 1 mapping. Updates the ExecutionContextScope part of the 
RegisterContext class to never return a stack frame to indicate this when it
is asked to recreate the execution context. Now register contexts point to the
concrete frame using a concrete frame index. Concrete frames are all of the
frames that are actually formed on the stack of a thread. These concrete frames
can be turned into one or more user visible frames due to inlining. Each 
inlined stack frame has the exact same register context (shared via shared
pointers) as any parent inlined stack frames all the way up to the concrete 
frame itself.

So now the stack frames and the register contexts should behave much better.

llvm-svn: 122976
2011-01-06 22:15:06 +00:00
Jason Molenda 8fed295cee Refactor UnwindLLDB so it doesn't populate the entire stack unless
the frame count is requested or each frame is individually requested.

In practice this doesn't seem to help anything because we have
functions like StackFrameList::GetNumFrames() which is going to
request each frame anyway.  And classes like ThreadPlanStepRange
and ThreadPlanStepOverRange get the stack depth in their ctor forcing
a full stack walk.  But at least UnwindLLDB will delay doing a full
walk if it can.

llvm-svn: 118477
2010-11-09 02:31:21 +00:00
Jason Molenda 45b4924550 Fix thinko in UnwindTable.cpp where it wouldn't provde a
FuncUnwinders object if the eh_frame section was missing
from an objfile.  Worked fine on x86_64 but on i386 where
eh_frame is unusual, that resulted in the arch default 
UnwindPlan being used all the time instead of picking up
an assembly profile based unwindplan.

llvm-svn: 118467
2010-11-09 01:21:22 +00:00
Jason Molenda fa19c3e7d6 Built the native unwinder with all the warnings c++-4.2 could muster;
fixed them.  Added DISALLOW_COPY_AND_ASSIGN to classes that should
not be bitwise copied.  Added default initializers for member
variables that weren't being initialized in the ctor.  Fixed a few
shadowed local variable mistakes.

llvm-svn: 118240
2010-11-04 09:40:56 +00:00
Jason Molenda 5976200d43 Handle the case where no eh_frame section is present.
RegisterContextLLDB holds a reference to the SymbolContext
in the vector of Cursors that UnwindLLDB maintains.  Switch
UnwindLLDB to hold a vector of shared pointers of Cursors
so this reference doesn't become invalid.

Correctly falling back from the "fast" UnwindPlan to the
"full" UnwindPlan when additional registers need to be
retrieved.

llvm-svn: 118218
2010-11-04 00:53:20 +00:00
Jason Molenda ab4f1924db Check in the native lldb unwinder.
Not yet enabled as the default unwinder but there are no known
backtrace problems with the code at this point.

Added 'log enable lldb unwind' to help diagnose backtrace problems;
this output needs a little refining but it's a good first step.

eh_frame information is currently read unconditionally - the code
is structured to allow this to be delayed until it's actually needed.
There is a performance hit when you have to parse the eh_frame
information for any largeish executable/library so it's necessary
to avoid if possible.

It's confusing having both the UnwindPlan::RegisterLocation struct
and the RegisterConextLLDB::RegisterLocation struct, I need to rename
one of them.

The writing of registers isn't done in the RegisterConextLLDB subclass
yet; neither is the running of complex DWARF expressions from eh_frame
(e.g. used for _sigtramp on Mac OS X).

llvm-svn: 117256
2010-10-25 11:12:07 +00:00