Commit Graph

83 Commits

Author SHA1 Message Date
Jason Molenda fbcb7f2c4e The first part of an lldb native stack unwinder.
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
2010-09-10 07:49:16 +00:00
Caroline Tice 428a9a58fa If the file the user specifies can't be found in the current directory,
and the user didn't specify a particular directory, search for the file 
using the $PATH environment variable.

llvm-svn: 113575
2010-09-10 04:48:55 +00:00
Greg Clayton c9800667e4 Cleaned up the output of "image lookup --address <ADDR>" which involved
cleaning up the output of many GetDescription objects that are part of a 
symbol context. This fixes an issue where no ranges were being printed out
for functions, blocks and symbols.

llvm-svn: 113571
2010-09-10 01:30:46 +00:00
Caroline Tice f20e8239cd Add comments to InstanceSettings constructors explaining why they have
to be set up the way they are.  Comment out code that removes pending
settings for live instances (after the settings are copied over).

llvm-svn: 113519
2010-09-09 18:26:37 +00:00
Caroline Tice 101c7c2060 Make all debugger-level user settable variables into instance variables.
Make get/set variable at the debugger level always set the particular debugger's instance variables rather than
the default variables.

llvm-svn: 113474
2010-09-09 06:25:08 +00:00
Caroline Tice 91123da2d1 Make sure creating a pending instance doesn't also trigger creating a live instance; also make sure creating a
pending instance uses the specified instance name rather than creating a new one; add brackets to instance names
when searching for and removing pending instances.

llvm-svn: 113370
2010-09-08 17:48:55 +00:00
Greg Clayton e83e731ec1 Remove the Flags member in lldb_private::Module in favor of bitfield boolean
member variables.

Modified lldb_private::Module to have an accessor that can be used to tell if
a module is a dynamic link editor (dyld) as there are functions in dyld on
darwin that mirror functions in libc (malloc, free, etc) that should not
be used when doing function lookups by name in expressions if there are more
than one match when looking up functions by name.

llvm-svn: 113313
2010-09-07 23:40:05 +00:00
Jim Ingham a767c9a3ae The settings mutexes get used recursively, and deadlock if they are normal mutexes.
llvm-svn: 113309
2010-09-07 23:31:30 +00:00
Greg Clayton 8dc0a9879c Stop line entries from dumping full paths when addresses dump themselves as symbol contexts.
llvm-svn: 113292
2010-09-07 21:56:53 +00:00
Jim Ingham 95852755a8 Move common code from GetSettingsController in Process & Debugger into static functions
in UserSettingsController.cpp.

llvm-svn: 113268
2010-09-07 20:27:09 +00:00
Caroline Tice 49e2737eb4 Fix various minor bugs in the Settings stuff.
llvm-svn: 113245
2010-09-07 18:35:40 +00:00
Greg Clayton 3c68757c45 Fixed an error that could occur during disassembly that could cause a function name to be printed before the first _and_ the second instruction of disassembly when there are two symbols -- one debug symbol and one linker symbol.
llvm-svn: 113181
2010-09-06 23:11:45 +00:00
Caroline Tice 3df9a8dfd7 This is a very large commit that completely re-does the way lldb
handles user settable internal variables (the equivalent of set/show
variables in gdb).  In addition to the basic infrastructure (most of
which is defined in UserSettingsController.{h,cpp}, there are examples
of two classes that have been set up to contain user settable
variables (the Debugger and Process classes).  The 'settings' command
has been modified to be a command-subcommand structure, and the 'set',
'show' and 'append' commands have been moved into this sub-commabnd
structure.  The old StateVariable class has been completely replaced
by this, and the state variable dictionary has been removed from the
Command Interpreter.  Places that formerly accessed the state variable
mechanism have been modified to access the variables in this new
structure instead (checking the term-width; getting/checking the
prompt; etc.)

Variables are attached to classes; there are two basic "flavors" of
variables that can be set: "global" variables (static/class-wide), and
"instance" variables (one per instance of the class).  The whole thing
has been set up so that any global or instance variable can be set at
any time (e.g. on start up, in your .lldbinit file), whether or not
any instances actually exist (there's a whole pending and default
values mechanism to help deal with that).

llvm-svn: 113041
2010-09-04 00:03:46 +00:00
Greg Clayton e41e58997c Improved name demangling performance by 20% on darwin.
llvm-svn: 113032
2010-09-03 23:26:12 +00:00
Johnny Chen 725945d568 Fixed an lldb infrastructure bug, where the debugger should reaaly update its
execution context only when the process is still alive.  When running the test
suite, the debugger is launching and killing processes constantly.

This might be the cause of the test hang as reported in rdar://problem/8377854,
where the debugger was looping infinitely trying to update a supposedly stale
thread list.

llvm-svn: 113022
2010-09-03 22:35:47 +00:00
Greg Clayton 6dadd508e7 Added a new bool parameter to many of the DumpStopContext() methods that
might dump file paths that allows the dumping of full paths or just the
basenames. Switched the stack frame dumping code to use just the basenames for
the files instead of the full path.

Modified the StackID class to no rely on needing the start PC for the current
function/symbol since we can use the SymbolContextScope to uniquely identify
that, unless there is no symbol context scope. In that case we can rely upon
the current PC value. This saves the StackID from having to calculate the 
start PC when the StackFrame::GetStackID() accessor is called.

Also improved the StackID less than operator to correctly handle inlined stack
frames in the same stack.

llvm-svn: 112867
2010-09-02 21:44:10 +00:00
Greg Clayton 288bdf9c1d StackFrame objects now own ValueObjects for any frame variables (locals, args,
function statics, file globals and static variables) that a frame contains. 
The StackFrame objects can give out ValueObjects instances for
each variable which allows us to track when a variable changes and doesn't
depend on variable names when getting value objects.

StackFrame::GetVariableList now takes a boolean to indicate if we want to
get the frame compile unit globals and static variables.

The value objects in the stack frames can now correctly track when they have
been modified. There are a few more tweaks needed to complete this work. The
biggest issue is when stepping creates partial stacks (just frame zero usually)
and causes previous stack frames not to match up with the current stack frames
because the previous frames only has frame zero. We don't really want to 
require that all previous frames be complete since stepping often must check
stack frames to complete their jobs. I will fix this issue tomorrow.

llvm-svn: 112800
2010-09-02 02:59:18 +00:00
Jim Ingham 680e177833 Don't re-look up the symbol in ResolveSymbolContextForAddress.
llvm-svn: 112679
2010-08-31 23:51:36 +00:00
Jim Ingham e40e42181f Added a way to open the current source file & line in an external editor, and you can turn this on with:
lldb -e

llvm-svn: 112502
2010-08-30 19:44:40 +00:00
Greg Clayton 59e8fc1c74 Clarified the intent of the SymbolContextScope class in the header
documentation. Symbol now inherits from the symbol
context scope so that the StackID can use a "SymbolContextScope *"
instead of a blockID (which could have been the same as some other
blockID from another symbol file). 

Modified the stacks that are created on subsequent stops to reuse
the previous stack frame objects which will allow for some internal
optimization using pointer comparisons during stepping. 

llvm-svn: 112495
2010-08-30 18:11:35 +00:00
Greg Clayton 73b953bc1f Detect when ValueObject values change each time they are evaluated.
llvm-svn: 112331
2010-08-28 00:08:07 +00:00
Greg Clayton 68275d5e56 Made it so we update the current frames from the previous frames by doing STL
swaps on the variable list, value object list, and disassembly. This avoids
us having to try and update frame indexes and other things that were getting
out of sync.

llvm-svn: 112301
2010-08-27 21:47:54 +00:00
Jim Ingham 2976d00adb Change "Current" as in GetCurrentThread, GetCurrentStackFrame, etc, to "Selected" i.e. GetSelectedThread. Selected makes more sense, since these are set by some user action (a selection). I didn't change "CurrentProcess" since this is always controlled by the target, and a given target can only have one process, so it really can't be selected.
llvm-svn: 112221
2010-08-26 21:32:51 +00:00
Greg Clayton 288e5afe6b Fixed another issue with the inline stack frames where if the first frame
has inlined functions that all started at the same address, then the inlined
backtrace would not produce correct stack frames.

Also cleaned up and inlined a lot of stuff in lldb_private::Address.

Added a function to StackFrame to detect if the frame is a concrete frame so
we can detect the difference between actual frames and inlined frames.

llvm-svn: 111989
2010-08-24 22:59:52 +00:00
Greg Clayton 9da7bd0739 Got a lot of the kinks worked out in the inline support after debugging more
complex inlined examples.

StackFrame classes don't have a "GetPC" anymore, they have "GetFrameCodeAddress()".
This is because inlined frames will have a PC value that is the same as the 
concrete frame that owns the inlined frame, yet the code locations for the
frame can be different. We also need to be able to get the real PC value for
a given frame so that variables evaluate correctly. To get the actual PC
value for a frame you can use:

    addr_t pc = frame->GetRegisterContext()->GetPC();

Some issues with the StackFrame stomping on its own symbol context were 
resolved which were causing the information to change for a frame when the
stack ID was calculated. Also the StackFrame will now correctly store the
symbol context resolve flags for any extra bits of information that were 
looked up (if you ask for a block only and you find one, you will alwasy have
the compile unit and function).

llvm-svn: 111964
2010-08-24 21:05:24 +00:00