The OperatingSystem plug-ins allow code to detect threads in memory and then say "memory thread 0x11111" is backed by the actual thread 1.
You can then single step these virtual threads. A problem arose when thread specific breakpoints were used during thread plans where we would say "set a breakpoint on thread 0x11111" and we would hit the breakpoint on the real thread 1 and the thread IDs wouldn't match and we would get rid of the "stopped at breakpoint" stop info due to this mismatch. Code was added to ensure these events get forwarded and thus allow single stepping a memory thread to work correctly.
Added a test case for this as well.
<rdar://problem/19211770>
llvm-svn: 234364
The issue with Thumb IT (if/then) instructions is the IT instruction preceeds up to four instructions that are made conditional. If a breakpoint is placed on one of the conditional instructions, the instruction either needs to match the thumb opcode size (2 or 4 bytes) or a BKPT instruction needs to be used as these are always unconditional (even in a IT instruction). If BKPT instructions are used, then we might end up stopping on an instruction that won't get executed. So if we do stop at a BKPT instruction, we need to continue if the condition is not true.
When using the BKPT isntructions are easy in that you don't need to detect the size of the breakpoint that needs to be used when setting a breakpoint even in a thumb IT instruction. The bad part is you will now always stop at the opcode location and let LLDB determine if it should auto-continue. If the BKPT instruction is used, the BKPT that is used for ARM code should be something that also triggers the BKPT instruction in Thumb in case you set a breakpoint in the middle of code and the code is actually Thumb code. A value of 0xE120BE70 will work since the lower 16 bits being 0xBE70 happens to be a Thumb BKPT instruction.
The alternative is to use trap or illegal instructions that the kernel will translate into breakpoint hits. On Mac this was 0xE7FFDEFE for ARM and 0xDEFE for Thumb. The darwin kernel currently doesn't recognize any 32 bit Thumb instruction as a instruction that will get turned into a breakpoint exception (EXC_BREAKPOINT), so we had to use the BKPT instruction on Mac. The linux kernel recognizes a 16 and a 32 bit instruction as valid thumb breakpoint opcodes. The benefit of using 16 or 32 bit instructions is you don't stop on opcodes in a IT block when the condition doesn't match.
To further complicate things, single stepping on ARM is often implemented by modifying the BCR/BVR registers and setting the processor to stop when the PC is not equal to the current value. This means single stepping is another way the ARM target can stop on instructions that won't get executed.
This patch does the following:
1 - Fix the internal debugserver for Apple to use the BKPT instruction for ARM and Thumb
2 - Fix LLDB to catch when we stop in the middle of a Thumb IT instruction and continue if we stop at an instruction that won't execute
3 - Fixes this in a way that will work for any target on any platform as long as it is ARM/Thumb
4 - Adds a patch for ignoring conditions that don't match when in ARM mode (see below)
This patch also provides the code that implements the same thing for ARM instructions, though it is disabled for now. The ARM patch will check the condition of the instruction in ARM mode and continue if the condition isn't true (and therefore the instruction would not be executed). Again, this is not enable, but the code for it has been added.
<rdar://problem/19145455>
llvm-svn: 223851
See the following llvm change for details:
r213743 | tnorthover | 2014-07-23 05:32:47 -0700 (Wed, 23 Jul 2014) | 9 lines
AArch64: remove arm64 triple enumerator.
This change fixes build breaks on Linux and MacOSX lldb.
llvm-svn: 213755
These changes were written by Greg Clayton, Jim Ingham, Jason Molenda.
It builds cleanly against TOT llvm with xcodebuild. I updated the
cmake files by visual inspection but did not try a build. I haven't
built these sources on any non-Mac platforms - I don't think this
patch adds any code that requires darwin, but please let me know if
I missed something.
In debugserver, MachProcess.cpp and MachTask.cpp were renamed to
MachProcess.mm and MachTask.mm as they picked up some new Objective-C
code needed to launch processes when running on iOS.
llvm-svn: 205113
pure virtual base class and made StackFrame a subclass of that. As
I started to build on top of that arrangement today, I found that it
wasn't working out like I intended. Instead I'll try sticking with
the single StackFrame class -- there's too much code duplication to
make a more complicated class hierarchy sensible I think.
llvm-svn: 193983
defines a protocol that all subclasses will implement. StackFrame
is currently the only subclass and the methods that Frame vends are
nearly identical to StackFrame's old methods.
Update all callers to use Frame*/Frame& instead of pointers to
StackFrames.
This is almost entirely a mechanical change that touches a lot of
the code base so I'm committing it alone. No new functionality is
added with this patch, no new subclasses of Frame exist yet.
I'll probably need to tweak some of the separation, possibly moving
some of StackFrame's methods up in to Frame, but this is a good
starting point.
<rdar://problem/15314068>
llvm-svn: 193907
(normally undefined) as indicating a breakpoint hit, in addition
to the normal (EXC_BREAKPOINT, EXC_ARM_BREAKPOINT) pair.
<rdar://problem/13730366>
llvm-svn: 180216
to have it not named appropriately. Also in StopInfoMachException, we aren't testing for software or not software, just
whether the thing is a breakpoint we set. So don't use "software"...
llvm-svn: 175241
objects for the backlink to the lldb_private::Process. The issues we were
running into before was someone was holding onto a shared pointer to a
lldb_private::Thread for too long, and the lldb_private::Process parent object
would get destroyed and the lldb_private::Thread had a "Process &m_process"
member which would just treat whatever memory that used to be a Process as a
valid Process. This was mostly happening for lldb_private::StackFrame objects
that had a member like "Thread &m_thread". So this completes the internal
strong/weak changes.
Documented the ExecutionContext and ExecutionContextRef classes so that our
LLDB developers can understand when and where to use ExecutionContext and
ExecutionContextRef objects.
llvm-svn: 151009
a watchpoint for either the variable encapsulated by SBValue (Watch) or the pointee
encapsulated by SBValue (WatchPointee).
Removed SBFrame::WatchValue() and SBFrame::WatchLocation() API as a result of that.
Modified the watchpoint related test suite to reflect the change.
Plus replacing WatchpointLocation with Watchpoint throughout the code base.
There are still cleanups to be dome. This patch passes the whole test suite.
Check it in so that we aggressively catch regressions.
llvm-svn: 141925
iterate on the available watchpoint locations and to perform watchpoint manipulations.
I still need to export the SBWatchpointLocation class as well as the added watchpoint
manipulation methods to the Python interface. And write test cases for them.
llvm-svn: 140575
data sent back to the debugger. On the debugger side, use the opportunity during the
StopInfoMachException::CreateStopReasonWithMachException() method to set the hardware index
for the very watchpoint location.
llvm-svn: 139975
parse NOP instructions. I added the new table entries for the NOP for the
plain NOP, Yield, WFE, WFI, and SEV variants. Modified the opcode emulation
function EmulateInstructionARM::EmulateMOVRdSP(...) to notify us when it is
creating a frame. Also added an abtract way to detect the frame pointer
register for both the standard ARM ABI and for Darwin.
Fixed GDBRemoteRegisterContext::WriteAllRegisterValues(...) to correctly be
able to individually write register values back if case the 'G' packet is
not implemented or returns an error.
Modified the StopInfoMachException to "trace" stop reasons. On ARM we currently
use the BVR/BCR register pairs to say "stop when the PC is not equal to the
current PC value", and this results in a EXC_BREAKPOINT mach exception that
has 0x102 in the code.
Modified debugserver to create the short option string from long option
definitions to make sure it doesn't get out of date. The short option string
was missing many of the newer short option values due to a modification of
the long options defs, and not modifying the short option string.
llvm-svn: 131911
class now implements the Host functionality for a lot of things that make
sense by default so that subclasses can check:
int
PlatformSubclass::Foo ()
{
if (IsHost())
return Platform::Foo (); // Let the platform base class do the host specific stuff
// Platform subclass specific code...
int result = ...
return result;
}
Added new functions to the platform:
virtual const char *Platform::GetUserName (uint32_t uid);
virtual const char *Platform::GetGroupName (uint32_t gid);
The user and group names are cached locally so that remote platforms can avoid
sending packets multiple times to resolve this information.
Added the parent process ID to the ProcessInfo class.
Added a new ProcessInfoMatch class which helps us to match processes up
and changed the Host layer over to using this new class. The new class allows
us to search for processs:
1 - by name (equal to, starts with, ends with, contains, and regex)
2 - by pid
3 - And further check for parent pid == value, uid == value, gid == value,
euid == value, egid == value, arch == value, parent == value.
This is all hookup up to the "platform process list" command which required
adding dumping routines to dump process information. If the Host class
implements the process lookup routines, you can now lists processes on
your local machine:
machine1.foo.com % lldb
(lldb) platform process list
PID PARENT USER GROUP EFF USER EFF GROUP TRIPLE NAME
====== ====== ========== ========== ========== ========== ======================== ============================
99538 1 username usergroup username usergroup x86_64-apple-darwin FileMerge
94943 1 username usergroup username usergroup x86_64-apple-darwin mdworker
94852 244 username usergroup username usergroup x86_64-apple-darwin Safari
94727 244 username usergroup username usergroup x86_64-apple-darwin Xcode
92742 92710 username usergroup username usergroup i386-apple-darwin debugserver
This of course also works remotely with the lldb-platform:
machine1.foo.com % lldb-platform --listen 1234
machine2.foo.com % lldb
(lldb) platform create remote-macosx
Platform: remote-macosx
Connected: no
(lldb) platform connect connect://localhost:1444
Platform: remote-macosx
Triple: x86_64-apple-darwin
OS Version: 10.6.7 (10J869)
Kernel: Darwin Kernel Version 10.7.0: Sat Jan 29 15:17:16 PST 2011; root:xnu-1504.9.37~1/RELEASE_I386
Hostname: machine1.foo.com
Connected: yes
(lldb) platform process list
PID PARENT USER GROUP EFF USER EFF GROUP TRIPLE NAME
====== ====== ========== ========== ========== ========== ======================== ============================
99556 244 username usergroup username usergroup x86_64-apple-darwin trustevaluation
99548 65539 username usergroup username usergroup x86_64-apple-darwin lldb
99538 1 username usergroup username usergroup x86_64-apple-darwin FileMerge
94943 1 username usergroup username usergroup x86_64-apple-darwin mdworker
94852 244 username usergroup username usergroup x86_64-apple-darwin Safari
The lldb-platform implements everything with the Host:: layer, so this should
"just work" for linux. I will probably be adding more stuff to the Host layer
for launching processes and attaching to processes so that this support should
eventually just work as well.
Modified the target to be able to be created with an architecture that differs
from the main executable. This is needed for iOS debugging since we can have
an "armv6" binary which can run on an "armv7" machine, so we want to be able
to do:
% lldb
(lldb) platform create remote-ios
(lldb) file --arch armv7 a.out
Where "a.out" is an armv6 executable. The platform then can correctly decide
to open all "armv7" images for all dependent shared libraries.
Modified the disassembly to show the current PC value. Example output:
(lldb) disassemble --frame
a.out`main:
0x1eb7: pushl %ebp
0x1eb8: movl %esp, %ebp
0x1eba: pushl %ebx
0x1ebb: subl $20, %esp
0x1ebe: calll 0x1ec3 ; main + 12 at test.c:18
0x1ec3: popl %ebx
-> 0x1ec4: calll 0x1f12 ; getpid
0x1ec9: movl %eax, 4(%esp)
0x1ecd: leal 199(%ebx), %eax
0x1ed3: movl %eax, (%esp)
0x1ed6: calll 0x1f18 ; printf
0x1edb: leal 213(%ebx), %eax
0x1ee1: movl %eax, (%esp)
0x1ee4: calll 0x1f1e ; puts
0x1ee9: calll 0x1f0c ; getchar
0x1eee: movl $20, (%esp)
0x1ef5: calll 0x1e6a ; sleep_loop at test.c:6
0x1efa: movl $12, %eax
0x1eff: addl $20, %esp
0x1f02: popl %ebx
0x1f03: leave
0x1f04: ret
This can be handy when dealing with the new --line options that was recently
added:
(lldb) disassemble --line
a.out`main + 13 at test.c:19
18 {
-> 19 printf("Process: %i\n\n", getpid());
20 puts("Press any key to continue..."); getchar();
-> 0x1ec4: calll 0x1f12 ; getpid
0x1ec9: movl %eax, 4(%esp)
0x1ecd: leal 199(%ebx), %eax
0x1ed3: movl %eax, (%esp)
0x1ed6: calll 0x1f18 ; printf
Modified the ModuleList to have a lookup based solely on a UUID. Since the
UUID is typically the MD5 checksum of a binary image, there is no need
to give the path and architecture when searching for a pre-existing
image in an image list.
Now that we support remote debugging a bit better, our lldb_private::Module
needs to be able to track what the original path for file was as the platform
knows it, as well as where the file is locally. The module has the two
following functions to retrieve both paths:
const FileSpec &Module::GetFileSpec () const;
const FileSpec &Module::GetPlatformFileSpec () const;
llvm-svn: 128563
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
This will allow debugger plug-ins to make any instance of "lldb_private::StopInfo"
that can completely describe any stop reason. It also provides a framework for
doing intelligent things with the stop info at important times in the lifetime
of the inferior.
Examples include the signal stop info in StopInfoUnixSignal. It will check with
the process to see that the current action is for the signal. These actions
include wether to stop for the signal, wether the notify that the signal was
hit, and wether to pass the signal along to the inferior process. The
StopInfoUnixSignal class overrides the "ShouldStop()" method of StopInfo and
this allows the stop info to determine if it should stop at the signal or
continue the process.
StopInfo subclasses must override the following functions:
virtual lldb::StopReason
GetStopReason () const = 0;
virtual const char *
GetDescription () = 0;
StopInfo subclasses can override the following functions:
// If the subclass returns "false", the inferior will resume. The default
// version of this function returns "true" which means the default stop
// info will stop the process. The breakpoint subclass will check if
// the breakpoint wants us to stop by calling any installed callback on
// the breakpoint, and also checking if the breakpoint is for the current
// thread. Signals will check if they should stop based off of the
// UnixSignal settings in the process.
virtual bool
ShouldStop (Event *event_ptr);
// Sublasses can state if they want to notify the debugger when "ShouldStop"
// returns false. This would be handy for breakpoints where you want to
// log information and continue and is also used by the signal stop info
// to notify that a signal was received (after it checks with the process
// signal settings).
virtual bool
ShouldNotify (Event *event_ptr)
{
return false;
}
// Allow subclasses to do something intelligent right before we resume.
// The signal class will figure out if the signal should be propagated
// to the inferior process and pass that along to the debugger plug-ins.
virtual void
WillResume (lldb::StateType resume_state)
{
// By default, don't do anything
}
The support the Mach exceptions was moved into the lldb/source/Plugins/Process/Utility
folder and now doesn't polute the lldb_private::Thread class with platform
specific code.
llvm-svn: 110184
Greg Clayton