an interface to a local or remote debugging platform. By default each host OS
that supports LLDB should be registering a "default" platform that will be
used unless a new platform is selected. Platforms are responsible for things
such as:
- getting process information by name or by processs ID
- finding platform files. This is useful for remote debugging where there is
an SDK with files that might already or need to be cached for debug access.
- getting a list of platform supported architectures in the exact order they
should be selected. This helps the native x86 platform on MacOSX select the
correct x86_64/i386 slice from universal binaries.
- Connect to remote platforms for remote debugging
- Resolving an executable including finding an executable inside platform
specific bundles (macosx uses .app bundles that contain files) and also
selecting the appropriate slice of universal files for a given platform.
So by default there is always a local platform, but remote platforms can be
connected to. I will soon be adding a new "platform" command that will support
the following commands:
(lldb) platform connect --name machine1 macosx connect://host:port
Connected to "machine1" platform.
(lldb) platform disconnect macosx
This allows LLDB to be well setup to do remote debugging and also once
connected process listing and finding for things like:
(lldb) process attach --name x<TAB>
The currently selected platform plug-in can now auto complete any available
processes that start with "x". The responsibilities for the platform plug-in
will soon grow and expand.
llvm-svn: 127286
of Stephen Wilson's idea (thanks for the input Stephen!). What I ended up
doing was:
- Got rid of ArchSpec::CPU (which was a generic CPU enumeration that mimics
the contents of llvm::Triple::ArchType). We now rely upon the llvm::Triple
to give us the machine type from llvm::Triple::ArchType.
- There is a new ArchSpec::Core definition which further qualifies the CPU
core we are dealing with into a single enumeration. If you need support for
a new Core and want to debug it in LLDB, it must be added to this list. In
the future we can allow for dynamic core registration, but for now it is
hard coded.
- The ArchSpec can now be initialized with a llvm::Triple or with a C string
that represents the triple (it can just be an arch still like "i386").
- The ArchSpec can still initialize itself with a architecture type -- mach-o
with cpu type and subtype, or ELF with e_machine + e_flags -- and this will
then get translated into the internal llvm::Triple::ArchSpec + ArchSpec::Core.
The mach-o cpu type and subtype can be accessed using the getter functions:
uint32_t
ArchSpec::GetMachOCPUType () const;
uint32_t
ArchSpec::GetMachOCPUSubType () const;
But these functions are just converting out internal llvm::Triple::ArchSpec
+ ArchSpec::Core back into mach-o. Same goes for ELF.
All code has been updated to deal with the changes.
This should abstract us until later when the llvm::TargetSpec stuff gets
finalized and we can then adopt it.
llvm-svn: 126278
module's AST context. Prior to this fix, with gcc binaries, we end up with
a full class definition for any used classes in each compile unit due to the
one definition rule. This would result in us making N copies of class T, where
N is the number of compile units that use class T, in the module AST. When
an expression would then try and use any types that were duplicated, it would
quickly confuse clang and make expression evaluation fail due to all of the
duplicate types that got copied over. This is now fixed by making a map of
types in the DWARF that maps type names to a collection of types + declaration
(file + line number) + DIE. Then later when we find a type we look in this
module map and find any already cached types that we can just use.
8935777
llvm-svn: 125207
cache even when a valid process exists. Previously, Target::ReadMemory would
read from the process if there was a valid one and then fallback to the
object file cache.
llvm-svn: 122989
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
we're using the stack pointer to define the CFA again. Makes unwinds
while sitting at the 'ret' instruction work, assuming we have accurate
function address bounds.
llvm-svn: 119327
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
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
prologue profiling.
Change the log print statements to elide the thread number, make
some of them only print when IsLogVerbose().
Add a couple of sanity checks for impossible CFA values so backtraces
don't go too far off into the weeds.
llvm-svn: 117343
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
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
