Commit Graph

5 Commits

Author SHA1 Message Date
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