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
Fixed include:
- Change Platform::ResolveExecutable(...) to take a ModuleSpec instead of a FileSpec + ArchSpec to help resolve executables correctly when we have just a path + UUID (no arch).
- Add the ability to set the listener in SBLaunchInfo and SBAttachInfo in case you don't want to use the debugger as the default listener.
- Modified all places that use the SBLaunchInfo/SBAttachInfo and the internal ProcessLaunchInfo/ProcessAttachInfo to not take a listener as a parameter since it is in the launch/attach info now
- Load a module's sections by default when removing a module from a target. Since we create JIT modules for expressions and helper functions, we could end up with stale data in the section load list if a module was removed from the target as the section load list would still have entries for the unloaded module. Target now has the following functions to help unload all sections a single or multiple modules:
size_t
Target::UnloadModuleSections (const ModuleList &module_list);
size_t
Target::UnloadModuleSections (const lldb::ModuleSP &module_sp);
llvm-svn: 222167
Improvements include:
* Use of libedit's wide character support, which is imperfect but a distinct improvement over ASCII-only
* Fallback for ASCII editing path
* Support for a "faint" prompt clearly distinguished from input
* Breaking lines and insert new lines in the middle of a batch by simply pressing return
* Joining lines with forward and backward character deletion
* Detection of paste to suppress automatic formatting and statement completion tests
* Correctly reformatting when lines grow or shrink to occupy different numbers of rows
* Saving multi-line history, and correctly preserving the "tip" of history during editing
* Displaying visible ^C and ^D indications when interrupting input or sending EOF
* Fledgling VI support for multi-line editing
* General correctness and reliability improvements
llvm-svn: 222163
There were many issues with synchronous mode that we discovered when started to try and add a "batch" mode. There was a race condition where the event handling thread might consume events when in sync mode and other times the Process::WaitForProcessToStop() would consume them. This also led to places where the Process IO handler might or might not get popped when it needed to be.
llvm-svn: 220254
an uninitialized value. In reality the code block that
initializes it and the code block that restores it will always
match up - but the analyzer doesn't know that and I want to
quiet it, so...
clang static analyzer fixit.
llvm-svn: 219869
Reviewed at http://reviews.llvm.org/D5738
This adds an SB API into SBProcess:
bool SBProcess::IsInstrumentationRuntimePresent(InstrumentationRuntimeType type);
which simply tells whether a particular InstrumentationRuntime (read "ASan") plugin is present and active.
llvm-svn: 219560
Reviewed at http://reviews.llvm.org/D5592
This patch gives LLDB some ability to interact with AddressSanitizer runtime library, on top of what we already have (historical memory stack traces provided by ASan). Namely, that's the ability to stop on an error caught by ASan, and access the report information that are associated with it. The report information is also exposed into SB API.
More precisely this patch...
adds a new plugin type, InstrumentationRuntime, which should serve as a generic superclass for other instrumentation runtime libraries, these plugins get notified when modules are loaded, so they get a chance to "activate" when a specific dynamic library is loaded
an instance of this plugin type, AddressSanitizerRuntime, which activates itself when it sees the ASan dynamic library or founds ASan statically linked in the executable
adds a collection of these plugins into the Process class
AddressSanitizerRuntime sets an internal breakpoint on __asan::AsanDie(), and when this breakpoint gets hit, it retrieves the report information from ASan
this breakpoint is then exposed as a new StopReason, eStopReasonInstrumentation, with a new StopInfo subclass, InstrumentationRuntimeStopInfo
the StopInfo superclass is extended with a m_extended_info field (it's a StructuredData::ObjectSP), that can hold arbitrary JSON-like data, which is the way the new plugin provides the report data
the "thread info" command now accepts a "-s" flag that prints out the JSON data of a stop reason (same way the "-j" flag works now)
SBThread has a new API, GetStopReasonExtendedInfoAsJSON, which dumps the JSON string into a SBStream
adds a test case for all of this
I plan to also get rid of the original ASan plugin (memory history stack traces) and use an instance of AddressSanitizerRuntime for that purpose.
Kuba
llvm-svn: 219546
As part of getting ConnectionFileDescriptor working on Windows,
there is going to be alot of platform specific work to be done.
As a result, the implementation is moving into Host. This patch
performs the code move and fixes up call-sites appropriately.
Reviewed by: Greg Clayton
Differential Revision: http://reviews.llvm.org/D5548
llvm-svn: 219143
There are several places where multiple threads are accessing the same variables simultaneously without any kind of protection. I propose using std::atomic<> to make it safer. I did a special build of lldb, using the google tool 'thread sanitizer' which identified many cases of multiple threads accessing the same memory. std::atomic is low overhead and does not use any locks for simple types such as int/bool.
See http://reviews.llvm.org/D5302 for more details.
Change by Shawn Best.
llvm-svn: 217818
This patch moves creates a thread abstraction that represents a
thread running inside the LLDB process. This is a replacement for
otherwise using lldb::thread_t, and provides a platform agnostic
interface to managing these threads.
Differential Revision: http://reviews.llvm.org/D5198
Reviewed by: Jim Ingham
llvm-svn: 217460
lldb's internal memory cache chunks that are read from the remote
system. For a remote connection that is especially slow, a user may
need to reduce it; reading a 512 byte chunk of memory whenever a
4-byte region is requested may not be the right decision in these
kinds of environments.
<rdar://problem/18175117>
llvm-svn: 217083
See http://reviews.llvm.org/D5108 for details.
This change does the following:
* eliminates the Process::GetUnixSignals() virtual method and replaces with a fixed getter.
* replaces the Process UnixSignals storage with a shared pointer.
* adds a Process constructor variant that can be passed the UnixSignalsSP. When the constructor without the UnixSignalsSP is specified, the Host's default UnixSignals is used.
* adds a host-specific version of GetUnixSignals() that is used when we need the host's appropriate UnixSignals variant.
* replaces GetUnixSignals() overrides in PlatformElfCore, ProcessGDBRemote, ProcessFreeBSD and ProcessLinux with code that appropriately sets the Process::UnixSignals for the process.
This change also enables some future patches that will enable llgs to be used for local Linux debugging.
llvm-svn: 216748
This change modifies the 'process launch' --disable-aslr option to take a boolean argument. If the user directly specifies --disable-aslr {true,false}, that setting will control whether the process is launched with ASLR disabled accordingly. In the event that the setting is not explicitly made on the process launch command line, then the value is retrieved from the target.disable-aslr setting (i.e. settings show target.disable-aslr).
llvm-svn: 215996
More specifically, this change can be summarized as follows:
1) Makes an lldbHostPosix library which contains code common to
all posix platforms.
2) Creates Host/FileSystem.h which defines a common FileSystem
interface.
3) Implements FileSystem.h in Host/windows and Host/posix.
4) Creates Host/FileCache.h, implemented in Host/common, which
defines a class useful for storing handles to open files needed
by the debugger.
Differential Revision: http://reviews.llvm.org/D4889
llvm-svn: 215775
FileAction was previously a nested class in ProcessLaunchInfo.
This led to some unfortunate style consequences, such as requiring
the AddPosixSpawnFileAction() funciton to be defined in the Target
layer, instead of the more appropriate Host layer. This patch
makes FileAction its own independent class in the Target layer,
and then moves AddPosixSpawnFileAction() into Host as a result.
Differential Revision: http://reviews.llvm.org/D4877
llvm-svn: 215649
result variable and use in in "Process::LoadImage" so that,
for instance, "process load" doesn't increment the return
variable number.
llvm-svn: 213440
The problem was that we have an IOHandler thread that services the IOHandler stack. The command interepter is on the top of the stack and it receives a "expression ..." command, and it calls the IOHandlerIsComplete() callback in the command interpereter delegate which runs an expression. This causes the IOHandlerProcessSTDIO to be pushed, but since we are running the code from the IOHandler thread, it won't get run. When CTRL+C is pressed, we do deliver the interrupt to the IOHandlerProcessSTDIO::Interrupt() function, but it was always writing 'i' to the interrupt pipe, even if we weren't actively reading from the debugger input and the pipes. This fix works around the issue by directly issuing the async interrupt to the process if the process is running.
A longer term more correct fix would to be run the IOHandler thread and have it just do the determination of the input and when complete input is received, run the code that handles that input on another thread and syncronize with that other thread to detect when more input is desired. That change is too big to make right now, so this fix will tide us over until we can get there.
<rdar://problem/16556228>
llvm-svn: 213196
This value gets set to a max uint32_t value when there is no known limit; otherwise,
it is set to a value appropriate for the platform. For the moment, only
Linux, FreeBSD and NetBSD set it to 16. All other platforms set it to
the max uint32_t value.
Modifies the Process private state thread names to fit within a 16-character limit
when the max thread name length is <= 16. These guarantee that the thread names
can be distinguished within the first 16 characters. Prior to this change, those
threads had names in the final dotted name segment that were not distinguishable
within the first 16 characters.
llvm-svn: 213183
This reverses out the options validators changes. We'll get these
back in once the changes to the output can be resolved.
Restores broken tests on FreeBSD, Linux, MacOSX.
Changes reverted: r212500, r212317, r212290.
llvm-svn: 212543
The purpose of the OptionValidator is to determine, based on some
arbitrary set of conditions, whether or not a command option is
valid for a given debugger state. An example of this might be
to selectively disable or enable certain command options that
don't apply to a particular platform.
This patch contains no functional change, and does not actually
make use of an OptionValidator for any purpose yet. A follow-up
patch will begin to add the logic and users of OptionValidator.
Reviewed by: Greg Clayton, Jim Ingham
Differential Revision: http://reviews.llvm.org/D4369
llvm-svn: 212290
Windows does support pipes, but they do so in a slightly different way. Added a Host layer which abstracts the use of pipes into a new Pipe class that everyone can use.
Windows benefits include:
- Being able to interrupt running processes when IO is directly hooked up
- being able to interrupt long running python scripts
- being able to interrupt anything based on ConnectionFileDescriptor
llvm-svn: 212220
This change brings in lldb-gdbserver (llgs) specifically for Linux x86_64.
(More architectures coming soon).
Not every debugserver option is covered yet. Currently
the lldb-gdbserver command line can start unattached,
start attached to a pid (process-name attach not supported yet),
or accept lldb attaching and launching a process or connecting
by process id.
The history of this large change can be found here:
https://github.com/tfiala/lldb/tree/dev-tfiala-native-protocol-linux-x86_64
Until mid/late April, I was not sharing the work and continued
to rebase it off of head (developed via id tfiala@google.com). I switched over to
user todd.fiala@gmail.com in the middle, and once I went to github, I did
merges rather than rebasing so I could share with others.
llvm-svn: 212069
Elevate ProcessInfo and ProcessLaunchInfo into their own headers.
llgs will be using ProcessLaunchInfo but doesn't need to pull in
the rest of Process.h.
This also moves a bunch of implementation details from the header
declarations into ProcessInfo.cpp and ProcessLaunchInfo.cpp.
Tested on Ubuntu 14.04 Cmake and MacOSX Xcode.
Related to https://github.com/tfiala/lldb/issues/26.
llvm-svn: 212005
Add a callback that will allow an expression to be cancelled between the
expression evaluation stages (for the ClangUserExpressions.)
<rdar://problem/16790467>, <rdar://problem/16573440>
llvm-svn: 207944
- CTRL+C wasn't clearing the command in lldb
- CTRL+C doesn't work in python macros in lldb
- Ctrl+C no longer interrupts the running process that you attach to
<rdar://problem/15949205>
<rdar://problem/16778652>
<rdar://problem/16774411>
llvm-svn: 207816
but by the time we go to halt, it has already stopped by hitting the
function end breakpoint. That wasn't being shown to the threads so the
Function call thread plan didn't know its job was done.
<rdar://problem/16515785>
llvm-svn: 205803
This is a purely mechanical change explicitly casting any parameters for printf
style conversion. This cleans up the warnings emitted by gcc 4.8 on Linux.
llvm-svn: 205607
I carefully reviewed exactly how the IOHandlers interact and found places where we weren't properly controlling things. There should be no overlapping prompts and all output should now come out in a controlled fashion.
<rdar://problem/16111293>
llvm-svn: 202525
Also remove SetStopOthers from the ThreadPlanCallFunction, because if the value you have doesn't match what is
in the EvaluateExpressionOptions the plan was passed when created it won't work correctly.
llvm-svn: 202464
We now write a 'q' to indicate to exit the IOHandlerProcessSTDIO::Run(), and a 'i' to interrupt the process. This should make this code safer to use in a signal handler function.
llvm-svn: 202311
libldi library to collect extended backtrace information; switch
to the libBacktraceRecording library and its APIs. Complete the
work of adding QueueItems to Queues and allow for the QueueItems
to be interrogated about their extended backtraces in turn.
There's still cleanup and documentation to do on this code but the
code is functional and I it's a good time to get the work-in-progress
checked in.
<rdar://problem/15314027>
llvm-svn: 200822
The many many benefits include:
1 - Input/Output/Error streams are now handled as real streams not a push style input
2 - auto completion in python embedded interpreter
3 - multi-line input for "script" and "expression" commands now allow you to edit previous/next lines using up and down arrow keys and this makes multi-line input actually a viable thing to use
4 - it is now possible to use curses to drive LLDB (please try the "gui" command)
We will need to deal with and fix any buildbot failures and tests and arise now that input/output and error are correctly hooked up in all cases.
llvm-svn: 200263
symbols correctly. There were a couple of pieces to this.
1) When a breakpoint location finds itself pointing to an Indirect symbol, when the site for it is created
it needs to resolve the symbol and actually set the site at its target.
2) Not all breakpoints want to do this (i.e. a straight address breakpoint should always set itself on the
specified address, so somem machinery was needed to specify that.
3) I added some info to the break list output for indirect symbols so you could see what was happening.
Also I made it clear when we re-route through re-exported symbols.
4) I moved ResolveIndirectFunction from ProcessPosix to Process since it works the exact same way on Mac OS X
and the other posix systems. If we find a platform that doesn't do it this way, they can override the
call in Process.
5) Fixed one bug in RunThreadPlan, if you were trying to run a thread plan after a "running" event had
been broadcast, the event coalescing would cause you to miss the ThreadPlan running event. So I added
a way to override the coalescing.
6) Made DynamicLoaderMacOSXDYLD::GetStepThroughTrampolinePlan handle Indirect & Re-exported symbols.
<rdar://problem/15280639>
llvm-svn: 198976
libdispatch aka Grand Central Dispatch (GCD) queues. Still fleshing out the
documentation and testing of these but the overall API is settling down so it's
a good time to check it in.
<rdar://problem/15600370>
llvm-svn: 197190
Example code:
remote_platform = lldb.SBPlatform("remote-macosx");
remote_platform.SetWorkingDirectory("/private/tmp")
debugger.SetSelectedPlatform(remote_platform)
connect_options = lldb.SBPlatformConnectOptions("connect://localhost:1111");
err = remote_platform.ConnectRemote(connect_options)
if err.Success():
print >> result, 'Connected to remote platform:'
print >> result, 'hostname: %s' % (remote_platform.GetHostname())
src = lldb.SBFileSpec("/Applications/Xcode.app/Contents/SharedFrameworks/LLDB.framework", False)
dst = lldb.SBFileSpec()
# copy src to platform working directory since "dst" is empty
err = remote_platform.Install(src, dst);
if err.Success():
print >> result, '%s installed successfully' % (src)
else:
print >> result, 'error: failed to install "%s": %s' % (src, err)
Implemented many calls needed in lldb-platform to be able to install a directory that contains symlinks, file and directories.
The remote lldb-platform can now launch GDB servers on the remote system so that remote debugging can be spawned through the remote platform when connected to a remote platform.
The API in SBPlatform is subject to change and will be getting many new functions.
llvm-svn: 195273
do anything right now. Add a few new methods to the Thread base
class which HistoryThread needs. I think I updated all the
CMakeLists files correctly for the new plugin.
llvm-svn: 194756
something; add a new ExtendedThreadList to Process where they can be retained
for the duration of a public stop.
<rdar://problem/15314068>
llvm-svn: 194367
It completes the job of using EvaluateExpressionOptions consistently throughout
the inferior function calling mechanism in lldb begun in Greg's patch r194009.
It removes a handful of alternate calls into the ClangUserExpression/ClangFunction/ThreadPlanCallFunction which
were there for convenience. Using the EvaluateExpressionOptions removes the need for them.
Using that it gets the --debug option from Greg's patch to work cleanly.
It also adds another EvaluateExpressionOption to not trap exceptions when running expressions. You shouldn't
use this option unless you KNOW your expression can't throw beyond itself. This is:
<rdar://problem/15374885>
At present this is only available through the SB API's or python.
It fixes a bug where function calls would unset the ObjC & C++ exception breakpoints without checking whether
they were set by somebody else already.
llvm-svn: 194182
Fixed the test case for "test/functionalities/exec/TestExec.py" on Darwin.
The issue was breakpoints were persisting and causing problems. When we exec, we need to clear out the process and target and start fresh with nothing and let the breakpoints populate themselves again. This patch correctly clears out the breakpoints and also flushes the process so that the objects (process/thread/frame) give out valid information.
llvm-svn: 194106
Cleaned up ClangUserExpression::Evaluate() to have only one variant that takes a "const EvaluateExpressionOptions& options" instead of taking many arguments.
The "--debug" option is designed to allow you to debug your expression by stopping at the first instruction (it enables --ignore-breakpoints=true and --unwind-on-error=false) and allowing you to step through your JIT code. It needs to be more integrated with the thread plan, so I am checking this in so Jim Ingham can make it happen.
llvm-svn: 194009
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
Added a way to set hardware breakpoints from the "breakpoint set" command with the new "--hardware" option. Hardware breakpoints are not a request, they currently are a requirement. So when breakpoints are specified as hardware breakpoints, they might fail to be set when they are able to be resolved and should be used sparingly. This is currently hooked up for GDB remote debugging.
Linux and FreeBSD should quickly enable this feature if possible, or return an error for any breakpoints that are hardware breakpoint sites in the "virtual Error Process::EnableBreakpointSite (BreakpointSite *bp_site);" function.
llvm-svn: 192491
- By default, the above function will wait for at least one event
- Set wait_always=false to make the function return immediately if the process is already stopped
llvm-svn: 192301
that /bin/sh re-exec's itself to /bin/bash, so it needs one more resume when you
are using it as the shell than /bin/bash did or you will stop at the start of your
program, rather than running it.
So I added a Platform API to get the number of resumes needed when launching with
a particular shell, and set the right values for Mac OS X.
<rdar://problem/14935282>
llvm-svn: 190381
/bin/sh is more portable, and all systems with /bin/bash are expected to
have /bin/sh as well, even if only a link to bash.
Review: http://llvm-reviews.chandlerc.com/D1576
llvm-svn: 189879
Greg Clayton