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
There was an error in ORing mask which is used for getting a list of variables.
Previously, these constants were unnamed, and possible it become the reason of this
bug. Also added test case for -stack-list-local and -stack-list_arguments.
Patch from Ilia K <ki.stfu@gmail.com>.
llvm-svn: 223674
section for x86_64 and i386 targets on Darwin systems. Currently only the
compact unwind encoding for normal frame-using functions is supported but it
will be easy handle frameless functions when I have a bit more free time to
test it. The LSDA and personality routines for functions are also retrieved
correctly for functions from the compact unwind section.
This new code is very fresh -- it passes the lldb testsuite and I've done
by-hand inspection of many functions and am getting correct behavior for all
of them. There may need to be some bug fixing over the next couple weeks as
I exercise and test it further. But I think it's fine right now so I'm
committing it.
<rdar://problem/13220837>
llvm-svn: 223625
It was observed that we dont need to set stdin to unbuffered and setting console
to non-canonical mode.
Patch originally came from "Ilia K <ki.stfu@gmail.com>"
llvm-svn: 223353
There were 2 different patches in discussion. One using ioctl
and other using select. We decided to use the ioctl but committed
code also have some changes which were only needed for 'select'.
This patch removes them.
llvm-svn: 223227
for x86_64. i386, arm, arm64 aren't handled yet but those are minor
variations on this format.
This commit also adds code to read the symbol table out of the
binary and read the LC_FUNCTION_STARTS to augment the symbol table
with the start addresses of all the functions - and print the
function names when showing the unwind info.
llvm-svn: 222951
UNWIND_X86_64_MODE_STACK_IND mode is almost correct; extra stack
space allocated before the reg saves isn't handled right. Still a
little wobbily on the file addresses of functions. Finally understand
how the 6 registers that may be saved are ordered in just 10 its
of space -- the Lehmer code for the registers is derived and then
the sequence is encoded in a variable base number. Added some
comments with references to what the code is doing so it'll be
easier for others to track down.
llvm-svn: 222884
some commands that will get run if the target crashes.
Also fix the bug where the local .lldbinit file was not getting
sourced before not after the target was created from the file options on the
driver command line.
<rdar://problem/19019843>
llvm-svn: 222295
information from the compact unwind section used on darwin
for exception handling, and dump that information..
The UNWIND_X86_64_MODE_RBP_FRAME and UNWIND_X86_64_MODE_DWARF
entries look to be handled correctly.
UNWIND_X86_64_MODE_STACK_IMMD and UNWIND_X86_64_MODE_STACK_IND
are still a work in progress.
Only x86_64 is supported right now. Given that this is an
experiment in parsing the section contents, I don't expect to
add other architectures; they are trivial variations on this
arch. There exists a real dumper included in the Xcode tools,
unwinddump.
llvm-svn: 222127
a number of warnings to be enabled. The one making the most noise
across the code base right now is CLANG_WARN_UNREACHABLE_CODE = YES.
llvm-svn: 219910
after all the commands have been executed except if one of the commands was an execution control
command that stopped because of a signal or exception.
Also adds a variant of SBCommandInterpreter::HandleCommand that takes an SBExecutionContext. That
way you can run an lldb command targeted at a particular target, thread or process w/o having to
select same before running the command.
Also exposes CommandInterpreter::HandleCommandsFromFile to the SBCommandInterpreter API, since that
seemed generally useful.
llvm-svn: 219654
do that (RunCommandInterpreter, HandleCommands, HandleCommandsFromFile) to gather
the options into an options class. Also expose that to the SB API's.
Change the way the "-o" options to the lldb driver are processed so:
1) They are run synchronously - didn't really make any sense to run the asynchronously.
2) The stop on error
3) "quit" in one of the -o commands will not quit lldb - not the command interpreter
that was running the -o commands.
I added an entry to the run options to stop-on-crash, but I haven't implemented that yet.
llvm-svn: 219553
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
This patch fixes the codesigning of debugserver on OSX when built with
cmake. Without this you get this error when debugging:
error: process launch failed: unable to locate debugserver
Note: you also need to set LLDB_DEBUGSERVER_PATH to point to your built debugserver.
e.g. export LLDB_DEBUGSERVER_PATH=`pwd`/bin/debugserver
Change by dawn@burble.org.
Tested on MacOSX 10.9.5 and Xcode 6.1 Beta using cmake/ninja.
Verified no build break on Linux Ubuntu cmake/ninja and Xcode 6.1 canonical build.
llvm-svn: 218890
See http://reviews.llvm.org/D5495 for more details.
These are changes that are part of an effort to support building llgs, within the AOSP source tree, using the Android.mk
build system, when using the llvm/clang/lldb git repos from AOSP replaced with the experimental ones currently in
github.com/tfiala/aosp-{llvm,clang,lldb,compiler-rt}.
llvm-svn: 218568
Build break change by Paul Osmialowski.
Minor changes to argument passing (converted unintentional pass-by-value to pass-by-ref) by Todd.
llvm-svn: 218186
Changes include:
- fix it so you can select the "host" platform using "platform select host"
- change all callbacks that create platforms to returns shared pointers
- fix TestImageListMultiArchitecture.py to restore the "host" platform by running "platform select host"
- Add a new "PlatformSP Platform::Find(const ConstString &name)" method to get a cached platform
- cache platforms that are created and re-use them instead of always creating a new one
llvm-svn: 218145
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
We would previously simply assume that the write would always succeed. However,
write(2) may return -1 for error as well as fail to perform a complete write (in
which case the returned number of bytes will be less than the requested bytes).
Explicitly check if an error condition is encountered. This would previously
not be caught as we default initialized success to true. Add an assertion that
we always perform a complete write (a continuous retry could be added to ensure
that we finish writing completely).
This was caught by GCC's signed comparison warning and manual inspection.
llvm-svn: 217355
See thread here:
http://lists.cs.uiuc.edu/pipermail/lldb-commits/Week-of-Mon-20140825/012580.html
The original change I made there was due to a segfault. That was
caused by me directly calling PluginManager::Initialize (), with
PluginManager::Initialize() depending on HostInfo::Initialize () to
have been called already (which it wasn't).
The call to PluginManager::Initialize () was erroneous (at least at the
current time) since that method is already called by Debugger::Initialize()'s
implementation.
We will want to revisit initializing a smaller core of the debugger
suitable for lldb-gdbserver and lldb-platform.
llvm-svn: 216581
Greg Clayton