The Unwind and RegisterContext subclasses still need
to be finished; none of this code is used by lldb at
this point (unless you call into it by hand).
The ObjectFile class now has an UnwindTable object.
The UnwindTable object has a series of FuncUnwinders
objects (Function Unwinders) -- one for each function
in that ObjectFile we've backtraced through during this
debug session.
The FuncUnwinders object has a few different UnwindPlans.
UnwindPlans are a generic way of describing how to find
the canonical address of a given function's stack frame
(the CFA idea from DWARF/eh_frame) and how to restore the
caller frame's register values, if they have been saved
by this function.
UnwindPlans are created from different sources. One source is the
eh_frame exception handling information generated by the compiler
for unwinding an exception throw. Another source is an assembly
language inspection class (UnwindAssemblyProfiler, uses the Plugin
architecture) which looks at the instructions in the funciton
prologue and describes the stack movements/register saves that are
done.
Two additional types of UnwindPlans that are worth noting are
the "fast" stack UnwindPlan which is useful for making a first
pass over a thread's stack, determining how many stack frames there
are and retrieving the pc and CFA values for each frame (enough
to create StackFrameIDs). Only a minimal set of registers is
recovered during a fast stack walk.
The final UnwindPlan is an architectural default unwind plan.
These are provided by the ArchDefaultUnwindPlan class (which uses
the plugin architecture). When no symbol/function address range can
be found for a given pc value -- when we have no eh_frame information
and when we don't have a start address so we can't examine the assembly
language instrucitons -- we have to make a best guess about how to
unwind. That's when we use the architectural default UnwindPlan.
On x86_64, this would be to assume that rbp is used as a stack pointer
and we can use that to find the caller's frame pointer and pc value.
It's a last-ditch best guess about how to unwind out of a frame.
There are heuristics about when to use one UnwindPlan versues the other --
this will all happen in the still-begin-written UnwindLLDB subclass of
Unwind which runs the UnwindPlans.
llvm-svn: 113581
defines that are in "llvm/Support/MachO.h". This should allow ObjectFileMachO
and ObjectContainerUniversalMachO to be able to be cross compiled in Linux.
Also did some cleanup on the ASTType by renaming it to ClangASTType and
renaming the header file. Moved a lot of "AST * + opaque clang type *"
functionality from lldb_private::Type over into ClangASTType.
llvm-svn: 109046
enabled LLVM make style building and made this compile LLDB on Mac OS X. We
can now iterate on this to make the build work on both linux and macosx.
llvm-svn: 108009
type and sub-type, or an ELF e_machine value. Also added a generic CPU type
to the arch spec class so we can have a single arch definition that the LLDB
core code can use. Previously a lot of places in the code were using the
mach-o definitions from a macosx header file.
Switches over to using "llvm/Support/MachO.h" for the llvm::MachO::XXX for the
CPU types and sub types for mach-o ArchSpecs. Added "llvm/Support/ELF.h" so
we can use the "llvm::ELF::XXX" defines for the ELF ArchSpecs.
Got rid of all CPU_TYPE_ and CPU_SUBTYPE_ defines that were previously being
used in LLDB.
llvm-svn: 105806
Jason Molenda