was previously using the entire frame variable list instead of using the
in scope variable list. I added a new function to a stack frame:
lldb::VariableListSP
StackFrame::GetInScopeVariableList (bool get_file_globals);
This gets only variables that are in scope and they will be ordered such
that the variables from the current scope are first.
llvm-svn: 136745
Code cleanup:
- The Format Manager implementation is now split between two files: FormatClasses.{h|cpp} where the
actual formatter classes (ValueFormat, SummaryFormat, ...) are implemented and
FormatManager.{h|cpp} where the infrastructure classes (FormatNavigator, FormatManager, ...)
are contained. The wrapper code always remains in Debugger.{h|cpp}
- Several leftover fields, methods and comments from previous design choices have been removed
type category subcommands (enable, disable, delete) now can take a list of category names as input
- for type category enable, saying "enable A B C" is the same as saying
enable C
enable B
enable A
(the ordering is relevant in enabling categories, and it is expected that a user typing
enable A B C wants to look into category A, then into B, then into C and not the other
way round)
- for the other two commands, the order is not really relevant (however, the same inverted ordering
is used for consistency)
llvm-svn: 135494
instructions if they are conditional. Also fixed issues where the PC wasn't
getting bit zero stripped for ARM targets when a stack frame was thumb. We
now properly call through the GetOpcodeLoadAddress() functions to make sure
the addresses are properly stripped for any targets that may decorate up
their addresses.
We now don't pass the SIGSTOP signals along. We can revisit this soon, but
currently this was interfering with debugging some older ARM targets that
don't have vCont support in the GDB server.
llvm-svn: 134461
- ${*expr} now simply means to dereference expr before actually using it
- bitfields, array ranges and pointer ranges now work in a (hopefully) more natural and language-compliant way
a new class TypeHierarchyNavigator replicates the behavior of the FormatManager in going through type hierarchies
when one-lining summary strings, children's summaries can be used as well as values
llvm-svn: 134458
issue in the way block variables are marked as parsed. In the DWARF parser we
always parse all blocks for a function at once, so we can mark all blocks as
having all variables parsed and avoid recursive function calls to try and
reparse things that have already been handled.
Fixed an issue with how variables get scoped into blocks. The DWARF parser can
now handle abtract class definitions that contain concrete static variables.
When the concrete instance of the class functions get instantiated, they will
track down the concrete block for the abtract block and add the variable to
each block.
llvm-svn: 133302
inline contexts when the deepest most block is not inlined.
Added source path remappings to the lldb_private::Target class that allow it
to remap paths found in debug info so we can find source files that are elsewhere
on the current system.
Fixed disassembly by function name to disassemble inline functions that are
inside other functions much better and to show enough context before the
disassembly output so you can tell where things came from.
Added the ability to get more than one address range from a SymbolContext
class for the case where a block or function has discontiguous address ranges.
llvm-svn: 130044
pointer to a ValueObject or any of its dependent ValueObjects, and the whole cluster will
stay around as long as that shared pointer stays around.
llvm-svn: 130035
threads, and stack frame down in the lldb_private::Process,
lldb_private::Thread, lldb_private::StackFrameList and the
lldb_private::StackFrame classes. We had some command line
commands that had duplicate versions of the process status
output ("thread list" and "process status" for example).
Removed the "file" command and placed it where it should
have been: "target create". Made an alias for "file" to
"target create" so we stay compatible with GDB commands.
We can now have multple usable targets in lldb at the
same time. This is nice for comparing two runs of a program
or debugging more than one binary at the same time. The
new command is "target select <target-idx>" and also to see
a list of the current targets you can use the new "target list"
command. The flow in a debug session can be:
(lldb) target create /path/to/exe/a.out
(lldb) breakpoint set --name main
(lldb) run
... hit breakpoint
(lldb) target create /bin/ls
(lldb) run /tmp
Process 36001 exited with status = 0 (0x00000000)
(lldb) target list
Current targets:
target #0: /tmp/args/a.out ( arch=x86_64-apple-darwin, platform=localhost, pid=35999, state=stopped )
* target #1: /bin/ls ( arch=x86_64-apple-darwin, platform=localhost, pid=36001, state=exited )
(lldb) target select 0
Current targets:
* target #0: /tmp/args/a.out ( arch=x86_64-apple-darwin, platform=localhost, pid=35999, state=stopped )
target #1: /bin/ls ( arch=x86_64-apple-darwin, platform=localhost, pid=36001, state=exited )
(lldb) bt
* thread #1: tid = 0x2d03, 0x0000000100000b9a a.out`main + 42 at main.c:16, stop reason = breakpoint 1.1
frame #0: 0x0000000100000b9a a.out`main + 42 at main.c:16
frame #1: 0x0000000100000b64 a.out`start + 52
Above we created a target for "a.out" and ran and hit a
breakpoint at "main". Then we created a new target for /bin/ls
and ran it. Then we listed the targest and selected our original
"a.out" program, so we showed two concurent debug sessions
going on at the same time.
llvm-svn: 129695
expressions that are simple enough to get passed to the "frame var" underpinnings. The parser code will
have to be changed to also query for the dynamic types & offsets as it is looking up variables.
The behavior of "frame var" is controlled in two ways. You can pass "-d {true/false} to the frame var
command to get the dynamic or static value of the variables you are printing.
There's also a general setting:
target.prefer-dynamic-value (boolean) = 'true'
which is consulted if you call "frame var" without supplying a value for the -d option.
llvm-svn: 129623
plugin by name on the command line for when there is more than one disassembler
plugin.
Taught the Opcode class to dump itself so that "disassembler -b" will dump
the bytes correctly for each opcode type. Modified all places that were passing
the opcode bytes buffer in so that the bytes could be displayed to just pass
in a bool that indicates if we should dump the opcode bytes since the opcode
now lives inside llvm_private::Instruction.
llvm-svn: 128290
now, in addition to cpu type/subtype and architecture flavor, contains:
- byte order (big endian, little endian)
- address size in bytes
- llvm::Triple for true target triple support and for more powerful plug-in
selection.
llvm-svn: 125602
fragile ivars if requested. This was done by changing the previous second parameter
to an options bitfield that can be populated by logical OR'ing the new
StackFrame::ExpressionPathOption enum values together:
typedef enum ExpressionPathOption
{
eExpressionPathOptionCheckPtrVsMember = (1u << 0),
eExpressionPathOptionsNoFragileObjcIvar = (1u << 1),
};
So the old function was:
lldb::ValueObjectSP
StackFrame::GetValueForVariableExpressionPath (const char *var_expr, bool check_ptr_vs_member, Error &error);
But it is now:
lldb::ValueObjectSP
StackFrame::GetValueForVariableExpressionPath (const char *var_expr, uint32_t options, Error &error);
This allows the expression parser in Target::EvaluateExpression(...) to avoid
using simple frame variable expression paths when evaluating something that might
be a fragile ivar.
llvm-svn: 123938
the way LLDB lazily gets complete definitions for types within the debug info.
When we run across a class/struct/union definition in the DWARF, we will only
parse the full definition if we need to. This works fine for top level types
that are assigned directly to variables and arguments, but when we have a
variable with a class, lets say "A" for this example, that has a member:
"B *m_b". Initially we don't need to hunt down a definition for this class
unless we are ever asked to do something with it ("expr m_b->getDecl()" for
example). With my previous approach to lazy type completion, we would be able
to take a "A *a" and get a complete type for it, but we wouldn't be able to
then do an "a->m_b->getDecl()" unless we always expanded all types within a
class prior to handing out the type. Expanding everything is very costly and
it would be great if there were a better way.
A few months ago I worked with the llvm/clang folks to have the
ExternalASTSource class be able to complete classes if there weren't completed
yet:
class ExternalASTSource {
....
virtual void
CompleteType (clang::TagDecl *Tag);
virtual void
CompleteType (clang::ObjCInterfaceDecl *Class);
};
This was great, because we can now have the class that is producing the AST
(SymbolFileDWARF and SymbolFileDWARFDebugMap) sign up as external AST sources
and the object that creates the forward declaration types can now also
complete them anywhere within the clang type system.
This patch makes a few major changes:
- lldb_private::Module classes now own the AST context. Previously the TypeList
objects did.
- The DWARF parsers now sign up as an external AST sources so they can complete
types.
- All of the pure clang type system wrapper code we have in LLDB (ClangASTContext,
ClangASTType, and more) can now be iterating through children of any type,
and if a class/union/struct type (clang::RecordType or ObjC interface)
is found that is incomplete, we can ask the AST to get the definition.
- The SymbolFileDWARFDebugMap class now will create and use a single AST that
all child SymbolFileDWARF classes will share (much like what happens when
we have a complete linked DWARF for an executable).
We will need to modify some of the ClangUserExpression code to take more
advantage of this completion ability in the near future. Meanwhile we should
be better off now that we can be accessing any children of variables through
pointers and always be able to resolve the clang type if needed.
llvm-svn: 123613
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
function and also hooked up better error reporting for when things fail.
Fixed issues with trying to display children of pointers when none are
supposed to be shown (no children for function pointers, and more like this).
This was causing child value objects to be made that were correctly firing
an assertion.
llvm-svn: 121841
values or persistent expression variables. Now if an expression consists of
a value that is a child of a variable, or of a persistent variable only, we
will create a value object for it and make a ValueObjectConstResult from it to
freeze the value (for program variables only, not persistent variables) and
avoid running JITed code. For everything else we still parse up and JIT code
and run it in the inferior.
There was also a lot of clean up in the expression code. I made the
ClangExpressionVariables be stored in collections of shared pointers instead
of in collections of objects. This will help stop a lot of copy constructors on
these large objects and also cleans up the code considerably. The persistent
clang expression variables were moved over to the Target to ensure they persist
across process executions.
Added the ability for lldb_private::Target objects to evaluate expressions.
We want to evaluate expressions at the target level in case we aren't running
yet, or we have just completed running. We still want to be able to access the
persistent expression variables between runs, and also evaluate constant
expressions.
Added extra logging to the dynamic loader plug-in for MacOSX. ModuleList objects
can now dump their contents with the UUID, arch and full paths being logged with
appropriate prefix values.
Thread hardened the Communication class a bit by making the connection auto_ptr
member into a shared pointer member and then making a local copy of the shared
pointer in each method that uses it to make sure another thread can't nuke the
connection object while it is being used by another thread.
Added a new file to the lldb/test/load_unload test that causes the test a.out file
to link to the libd.dylib file all the time. This will allow us to test using
the DYLD_LIBRARY_PATH environment variable after moving libd.dylib somewhere else.
llvm-svn: 121745
RegisterContext* - normally this is retrieved from the ExecutionContext's
StackFrame but when we need to evaluate an expression while creating
the stack frame list this can be a little tricky.
Add DW_OP_deref_size, needed for the _sigtramp FDE expression.
Add support for processing DWARF expressions in RegisterContextLLDB.
Update callers to DWARFExpression::Evaluate.
llvm-svn: 119885
all of the calls inlined in the header file for better performance.
Fixed the summary for C string types (array of chars (with any combo if
modifiers), and pointers to chars) work in all cases.
Fixed an issue where a forward declaration to a clang type could cause itself
to resolve itself more than once if, during the resolving of the type itself
it caused something to try and resolve itself again. We now remove the clang
type from the forward declaration map in the DWARF parser when we start to
resolve it and avoid this additional call. This should stop any duplicate
members from appearing and throwing all the alignment of structs, unions and
classes.
llvm-svn: 117437
instance:
settings set frame-format <string>
settings set thread-format <string>
This allows users to control the information that is seen when dumping
threads and frames. The default values are set such that they do what they
used to do prior to changing over the the user defined formats.
This allows users with terminals that can display color to make different
items different colors using the escape control codes. A few alias examples
that will colorize your thread and frame prompts are:
settings set frame-format 'frame #${frame.index}: \033[0;33m${frame.pc}\033[0m{ \033[1;4;36m${module.file.basename}\033[0;36m ${function.name}{${function.pc-offset}}\033[0m}{ \033[0;35mat \033[1;35m${line.file.basename}:${line.number}}\033[0m\n'
settings set thread-format 'thread #${thread.index}: \033[1;33mtid\033[0;33m = ${thread.id}\033[0m{, \033[0;33m${frame.pc}\033[0m}{ \033[1;4;36m${module.file.basename}\033[0;36m ${function.name}{${function.pc-offset}}\033[0m}{, \033[1;35mstop reason\033[0;35m = ${thread.stop-reason}\033[0m}{, \033[1;36mname = \033[0;36m${thread.name}\033[0m}{, \033[1;32mqueue = \033[0;32m${thread.queue}}\033[0m\n'
A quick web search for "colorize terminal output" should allow you to see what
you can do to make your output look like you want it.
The "settings set" commands above can of course be added to your ~/.lldbinit
file for permanent use.
Changed the pure virtual
void ExecutionContextScope::Calculate (ExecutionContext&);
To:
void ExecutionContextScope::CalculateExecutionContext (ExecutionContext&);
I did this because this is a class that anything in the execution context
heirarchy inherits from and "target->Calculate (exe_ctx)" didn't always tell
you what it was really trying to do unless you look at the parameter.
llvm-svn: 115485
debug map showed that the location lists in the .o files needed some
refactoring in order to work. The case that was failing was where a function
that was in the "__TEXT.__textcoal_nt" in the .o file, and in the
"__TEXT.__text" section in the main executable. This made symbol lookup fail
due to the way we were finding a real address in the debug map which was
by finding the section that the function was in in the .o file and trying to
find this in the main executable. Now the section list supports finding a
linked address in a section or any child sections. After fixing this, we ran
into issue that were due to DWARF and how it represents locations lists.
DWARF makes a list of address ranges and expressions that go along with those
address ranges. The location addresses are expressed in terms of a compile
unit address + offset. This works fine as long as nothing moves around. When
stuff moves around and offsets change between the remapped compile unit base
address and the new function address, then we can run into trouble. To deal
with this, we now store supply a location list slide amount to any location
list expressions that will allow us to make the location list addresses into
zero based offsets from the object that owns the location list (always a
function in our case).
With these fixes we can now re-link random address ranges inside the debugger
for use with our DWARF + debug map, incremental linking, and more.
Another issue that arose when doing the DWARF in the .o files was that GCC
4.2 emits a ".debug_aranges" that only mentions functions that are externally
visible. This makes .debug_aranges useless to us and we now generate a real
address range lookup table in the DWARF parser at the same time as we index
the name tables (that are needed because .debug_pubnames is just as useless).
llvm-gcc doesn't generate a .debug_aranges section, though this could be
fixed, we aren't going to rely upon it.
Renamed a bunch of "UINT_MAX" to "UINT32_MAX".
llvm-svn: 113829
parent, sibling and first child block, and access to the
inline function information.
Added an accessor the StackFrame:
Block * lldb_private::StackFrame::GetFrameBlock();
LLDB represents inline functions as lexical blocks that have
inlined function information in them. The function above allows
us to easily get the top most lexical block that defines a stack
frame. When there are no inline functions in function, the block
returned ends up being the top most block for the function. When
the PC is in an inlined funciton for a frame, this will return the
first parent block that has inlined function information. The
other accessor: StackFrame::GetBlock() will return the deepest block
that matches the frame's PC value. Since most debuggers want to display
all variables in the current frame, the Block returned by
StackFrame::GetFrameBlock can be used to retrieve all variables for
the current frame.
Fixed the lldb_private::Block::DumpStopContext(...) to properly
display inline frames a block should display all of its inlined
functions. Prior to this fix, one of the call sites was being skipped.
This is a separate code path from the current default where inlined
functions get their own frames.
Fixed an issue where a block would always grab variables for any
child inline function blocks.
llvm-svn: 113195
Added extra logging for stepping.
Fixed an issue where cached stack frame data could be lost between runs when
the thread plans read a stack frame.
llvm-svn: 112973
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
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
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
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
instead of trying to maintain the real frame list (unwind frames) and an
inline frame list. The information is cheap to produce when we already have
looked up a block and was making stack frame uniquing difficult when trying
to use the previous stack when making the current stack.
We now maintain the previous value object lists for common frames between
a previous and current frames so we will be able to tell when variable values
change.
llvm-svn: 112277
code stepping. Also we now store the stack frames for the current and previous
stops in the thread in std::auto_ptr objects. When we create a thread stack
frame list we pass the previous frame into it so it can re-use the frames
and maintain will allow for variable changes to be detected. I will implement
the stack frame reuse next.
llvm-svn: 112152
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
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
which is now on by default. Frames are gotten from the unwinder as concrete
frames, then if inline frames are to be shown, extra information to track
and reconstruct these frames is cached with each Thread and exanded as needed.
I added an inline height as part of the lldb_private::StackID class, the class
that helps us uniquely identify stack frames. This allows for two frames to
shared the same call frame address, yet differ only in inline height.
Fixed setting breakpoint by address to not require addresses to resolve.
A quick example:
% cat main.cpp
% ./build/Debug/lldb test/stl/a.out
Current executable set to 'test/stl/a.out' (x86_64).
(lldb) breakpoint set --address 0x0000000100000d31
Breakpoint created: 1: address = 0x0000000100000d31, locations = 1
(lldb) r
Launching 'a.out' (x86_64)
(lldb) Process 38031 Stopped
* thread #1: tid = 0x2e03, pc = 0x0000000100000d31, where = a.out`main [inlined] std::string::_M_data() const at /usr/include/c++/4.2.1/bits/basic_string.h:280, stop reason = breakpoint 1.1, queue = com.apple.main-thread
277
278 _CharT*
279 _M_data() const
280 -> { return _M_dataplus._M_p; }
281
282 _CharT*
283 _M_data(_CharT* __p)
(lldb) bt
thread #1: tid = 0x2e03, stop reason = breakpoint 1.1, queue = com.apple.main-thread
frame #0: pc = 0x0000000100000d31, where = a.out`main [inlined] std::string::_M_data() const at /usr/include/c++/4.2.1/bits/basic_string.h:280
frame #1: pc = 0x0000000100000d31, where = a.out`main [inlined] std::string::_M_rep() const at /usr/include/c++/4.2.1/bits/basic_string.h:288
frame #2: pc = 0x0000000100000d31, where = a.out`main [inlined] std::string::size() const at /usr/include/c++/4.2.1/bits/basic_string.h:606
frame #3: pc = 0x0000000100000d31, where = a.out`main [inlined] operator<< <char, std::char_traits<char>, std::allocator<char> > at /usr/include/c++/4.2.1/bits/basic_string.h:2414
frame #4: pc = 0x0000000100000d31, where = a.out`main + 33 at /Volumes/work/gclayton/Documents/src/lldb/test/stl/main.cpp:14
frame #5: pc = 0x0000000100000d08, where = a.out`start + 52
Each inline frame contains only the variables that they contain and each inlined
stack frame is treated as a single entity.
llvm-svn: 111877
to spawn a thread for each process that is being monitored. Previously
LLDB would spawn a single thread that would wait for any child process which
isn't ok to do as a shared library (LLDB.framework on Mac OSX, or lldb.so on
linux). The old single thread used to call wait4() with a pid of -1 which
could cause it to reap child processes that it shouldn't have.
Re-wrote the way Function blocks are handles. Previously I attempted to keep
all blocks in a single memory allocation (in a std::vector). This made the
code somewhat efficient, but hard to work with. I got rid of the old BlockList
class, and went to a straight parent with children relationship. This new
approach will allow for partial parsing of the blocks within a function.
llvm-svn: 111706
Added the ability to read memory from the target's object files when we aren't
running, so disassembling works before you run!
Cleaned up the API to lldb_private::Target::ReadMemory().
Cleaned up the API to the Disassembler to use actual "lldb_private::Address"
objects instead of just an "addr_t". This is nice because the Address objects
when resolved carry along their section and module which can get us the
object file. This allows Target::ReadMemory to be used when we are not
running.
Added a new lldb_private::Address dump style: DumpStyleDetailedSymbolContext
This will show a full breakdown of what an address points to. To see some
sample output, execute a "image lookup --address <addr>".
Fixed SymbolContext::DumpStopContext(...) to not require a live process in
order to be able to print function and symbol offsets.
llvm-svn: 107350
to the debugger from GUI windows. Previously there was one global debugger
instance that could be accessed that had its own command interpreter and
current state (current target/process/thread/frame). When a GUI debugger
was attached, if it opened more than one window that each had a console
window, there were issues where the last one to setup the global debugger
object won and got control of the debugger.
To avoid this we now create instances of the lldb_private::Debugger that each
has its own state:
- target list for targets the debugger instance owns
- current process/thread/frame
- its own command interpreter
- its own input, output and error file handles to avoid conflicts
- its own input reader stack
So now clients should call:
SBDebugger::Initialize(); // (static function)
SBDebugger debugger (SBDebugger::Create());
// Use which ever file handles you wish
debugger.SetErrorFileHandle (stderr, false);
debugger.SetOutputFileHandle (stdout, false);
debugger.SetInputFileHandle (stdin, true);
// main loop
SBDebugger::Terminate(); // (static function)
SBDebugger::Initialize() and SBDebugger::Terminate() are ref counted to
ensure nothing gets destroyed too early when multiple clients might be
attached.
Cleaned up the command interpreter and the CommandObject and all subclasses
to take more appropriate arguments.
llvm-svn: 106615
Greg Clayton