When LLDB Python bindings are used and stack backtraces are enabled
for logging, getMainExecutable() is called with argv0 being null.
This caused the fallback function getprogpath() (used on FreeBSD, NetBSD
and Linux) to segfault. Make it handle null executable name gracefully.
Differential Revision: https://reviews.llvm.org/D91012
TestWatchpointMultipleThreads currently accounts for two scenarios:
setting the watchpoint before a new thread starts (presumably, verifying
that it will be propagated to the new thread) and setting it after
the thread starts (presumably, verifying that a new watchpoint is set
on all threads). However, the latter test currently assumes that
the thread will be reported to the debugger before the breakpoint is
hit. This is not the case on FreeBSD and NetBSD.
On NetBSD, new threads do not inherit debug registers from their parent
threads. Instead, LLDB copies them manually after the new thread is
reported. Since the thread is actually reported after the second
breakpoint location, both tests effectively check the same behavior
(i.e. watchpoint being set before the new thread is reported).
On FreeBSD, new threads inherit debug registers and we seem to hit
an interesting race condition. While the thread is reported after
the breakpoint is hit, the kernel seems to construct it and copy
the debug register before that happens. As a result, setting
the watchpoint at the second breakpoint location modifies the debug
registers of the first thread after they have been copied to the second
thread but before the debugger is aware of it. Therefore,
the watchpoint is not propagated to the second thread and the test
fails.
Extend the test to cover all three possible scenarios: setting
watchpoint before the thread is lanched, after it is launched but before
it is guaranteed to have started and after it has actually started. Add
a second barrier to account for the last case. This should ensure that
the second assumption (i.e. that the watchpoint is set on all currently
known threads) is actually tested on FreeBSD and NetBSD.
Differential Revision: https://reviews.llvm.org/D91030
Use skipUnlessDarwin decorator for tests that are specific to Darwin,
instead of skipIf... for all other platforms. This should make it clear
that these tests are not supposed to work elsewhere. It will also make
these tests stop repeatedly popping up while I look for tests that could
be fixed on the platform in question.
Differential Revision: https://reviews.llvm.org/D91003
Depends on D89408.
This diff finally implements trace decoding!
The current interface is
$ trace load /path/to/trace/session/file.json
$ thread trace dump instructions
thread #1: tid = 3842849, total instructions = 22
[ 0] 0x40052d
[ 1] 0x40052d
...
[19] 0x400521
$ # simply enter, which is a repeat command
[20] 0x40052d
[21] 0x400529
...
This doesn't do any disassembly, which will be done in the next diff.
Changes:
- Added an IntelPTDecoder class, that is a wrapper for libipt, which is the actual library that performs the decoding.
- Added TraceThreadDecoder class that decodes traces and memoizes the result to avoid repeating the decoding step.
- Added a DecodedThread class, which represents the output from decoding and that for the time being only stores the list of reconstructed instructions. Later it'll contain the function call hierarchy, which will enable reconstructing backtraces.
- Added basic APIs for accessing the trace in Trace.h:
- GetInstructionCount, which counts the number of instructions traced for a given thread
- IsTraceFailed, which returns an Error if decoding a thread failed
- ForEachInstruction, which iterates on the instructions traced for a given thread, concealing the internal storage of threads, as plug-ins can decide to generate the instructions on the fly or to store them all in a vector, like I do.
- DumpTraceInstructions was updated to print the instructions or show an error message if decoding was impossible.
- Tests included
Differential Revision: https://reviews.llvm.org/D89283
Remove the thread name caching code. It does not handle the possibility
of thread name changing between requests, therefore breaking
TestGdbRemoteThreadName. While technically we could cache the results
and reset the cache on resuming process, the gain from doing that
does not seem worth the effort.
Differential Revision: https://reviews.llvm.org/D90863
Fix TestGdbRemoteThreadName to call ::pthread_setname_np instead
of ::pthread_set_name_np on FreeBSD. While technically both names
are correct, the former is preferable because of compatibility
with Linux. Furthermore, the latter requires `#include <pthread_np.h>`
that was missing causing the test to fail to compile.
Differential Revision: https://reviews.llvm.org/D90862
The new FreeBSDRemote plugin has reached feature parity on i386
and amd64 targets. Use it by default on these architectures, while
allowing the use of the legacy plugin via FREEBSD_LEGACY_PLUGIN envvar.
Revisit the method of switching plugins. Apparently, the return value
of PlatformFreeBSD::CanDebugProcess() is what really decides whether
the legacy or the new plugin is used.
Update the test status. Reenable the tests that were previously
disabled on FreeBSD and do not cause hangs or are irrelevant to FreeBSD.
Mark all tests that fail reliably as expectedFailure. For now, tests
that are flaky (i.e. produce unstable results) are left enabled
and cause unpredictable test failures.
Differential Revision: https://reviews.llvm.org/D90757
`fork` is marked as `__WATCHOS_PROHIBITED __TVOS_PROHIBITED` so the test source
which is calling fork will never compile on watchOS/tvOS. This just adds the
skip decorator for these platforms.
Reviewed By: mib
Differential Revision: https://reviews.llvm.org/D89695
This is a follow up to D88792 which found an issue in a call to PExpectTest's
expect function that allows passing a string to the `substrs` parameter. However
this issue was found by just grepping and TestPExpect's expect function is still
accepting a single string as a value to `substrs`.
This patch adds the same sanity check that D88792 added to the PExpectTest's
implementation of `expect` and also adds a small test for it.
Reviewed By: kastiglione, JDevlieghere
Differential Revision: https://reviews.llvm.org/D89302
SBType::GetArrayElementType should return the actual type, not the
canonical type (e.g. int32_t, not the underlying int).
Added a test case to validate the new behavior. I also ran all other
tests on Linux (ninja check-lldb), they all pass.
Differential revision: https://reviews.llvm.org/D90318
This allows the Target to update its module list when loading a shared
module replaces an equivalent one.
A testcase is added which hits this codepath -- without the fix, the
target reports libbreakpad.so twice in its module list.
Reviewed By: jingham
Differential Revision: https://reviews.llvm.org/D89157
SymbolFileDWARF::GetTypes was not handling dwo correctly. The fix is
simple -- adding a GetNonSkeletonUnit call -- but I've snuck in a small
refactor as well.
Debug server is already launched by prep_debug_monitor_and_inferior. The
second seems to have been benign so far, but after 8cc49bec2 this test
started failing frequently on GreenDragon, and this is the only unusual
thing about it.
The intention is not to allow stop-hook commands to query the
user, so this is correct. It also works around a deadlock in
switching to the Python Session to execute python based commands
in the stop hook when the Debugger stdin is backed by a FILE *.
Differential Revision: https://reviews.llvm.org/D90332
This fixes an flakyness is all gdb-remote tests. These tests have been
(mildly) flaky since we started using "localhost" instead of 127.0.0.1
in the test suite. The reason is that lldb-server needs to create two
sockets (v4 and v6) to listen for localhost connections. The algorithm
it uses first tries to select a random port (bind(localhost:0)) for the
first address, and then bind the same port for the second one.
The creating of the second socket can fail as there's no guarantee that
port will be available -- it seems that the (linux) kernel tries to
choose an unused port for the first socket (I've had to create thousands
of sockets to reproduce this reliably), but this can apparantly fail
when the system is under load (and our test suite creates a _lot_ of
sockets).
The socket creationg operation is considered successful if it creates at
least one socket is created, but the test harness has no way of knowing
which one it is, so it can end up connecting to the wrong address.
I'm not aware of a way to atomically create two sockets bound to the
same port. One way to fix this would be to make lldb-server report the
address is it listening on instead of just the port. However, this would
be a breaking change and it's not clear to me that's worth it (the
algorithm works pretty well under normal circumstances).
Instead, this patch sidesteps that problem by using "reverse"
connections. This way, the test harness is responsible for creating the
listening socket so it can pass the address that it has managed to open.
It also results in much simpler code overall.
To preserve test coverage for the named pipe method, I've moved the
relevant code to a dedicated test. To avoid original problem, this test
passes raw addresses (as obtained by getaddrinfo(localhost)) instead of
"localhost".
Differential Revision: https://reviews.llvm.org/D90313
Replace the inline x86 watchpoint handling code with the reusable
NativeRegisterContextWatchpoint_x86. Implement watchpoint support
in NativeThreadFreeBSD and SIGTRAP handling for watchpoints.
Un-skip all concurrent_events tests as they pass with the new plugin.
Differential Revision: https://reviews.llvm.org/D90102
TestQuoting's different test methods all build their own test binaries but
we can just reuse the same test binary by merging all asserts into one method.
This reduces the test runtime from 8 seconds to 4 seconds on my machine.
This also removes the ability to have partial failures in this test, but given
how rarely this code is touched this seems like a fair tradeoff (and we will be
able to re-add this feature once we updated our test framework).
Some other small changes:
* Fixed that we cleanup "stdout.txt" instead of "output.txt" in the cleanup.
* Fixed some formatting issues.
* Call `build` instead of directly calling `buildDefault`.
Displaying large packed bitfields did not work if one was accessing them
through a pointer, and he used the "->" notation ("[0]." notation is
fine). The reason for that is that implicit dereference in -> is plumbed
all the way down to ValueObjectChild::UpdateValue, where the process of
fetching the child value was forked for this flag. The bitfield
"sliding" code was implemented only for the branch which did not require
dereferencing.
This patch restructures the function to avoid this mistake. Processing
now happens in two stages.
- first the parent is dereferenced (if needed)
- then the child value is computed (this step includes sliding and is
common for both branches)
Differential Revision: https://reviews.llvm.org/D89236
In a new Range class was introduced to simplify and the Disassembler API
and reduce duplication. It unintentionally broke the
SBFrame::Disassemble functionality because it unconditionally converts
the number of instructions to a Range{Limit::Instructions,
num_instructions}. This is subtly different from the previous behavior,
where now we're passing a Range and assume it's valid in the callee, the
original code would propagate num_instructions and the callee would
compare the value and decided between disassembling instructions or
bytes.
Unfortunately the existing tests was not particularly strict:
disassembly = frame.Disassemble()
self.assertNotEqual(len(disassembly), 0, "Disassembly was empty.")
This would pass because without this patch we'd disassemble zero
instructions, resulting in an error:
(lldb) script print(lldb.frame.Disassemble())
error: error reading data from section __text
Differential revision: https://reviews.llvm.org/D89925
This test checks that the output of `SBTarget.GetDescription()` contains the
substrings `'a.out', 'Target', 'Module', 'Breakpoint'` in that order. This test
is currently failing on Apple simulators as apparently 'Module' can't be found
in the output after 'Target".
The reason for that is that the actual output of `SBTarget.GetDescription()` looks like this:
```
Target
Module /build/path/lldb-test-build.noindex/python_api/target/TestTargetAPI.test_get_description_dwarf/a.out
0x7ff2b6d3f990: ObjectFileMachO64, file = /build/path/lldb-test-build.noindex/python_api/target/TestTargetAPI.test_get_description
[...]
0x7ff307150000: BreakpointList with 0 Breakpoints:
<LLDB module output repeats for each loaded module>
```
Clearly the string order should be `'Target', 'Module', 'a.out', 'Breakpoint'`.
However, LLDB is also a bunch of system shared libraries (libxpc.dylib,
libobjc.A.dylib, etc.) when *not* running against a simulator, we end up
unintentionally finding the `'Target', 'Module', 'Breakpoint'` substrings in the
trailing descriptions of the system modules. When running against a simulator we
however don't load shared system libraries.
This patch just moves the substrings in the correct order to make this test pass
without having any shared library modules in the description output.
Reviewed By: JDevlieghere
Differential Revision: https://reviews.llvm.org/D89698
When opening a minidump, we might discover that it reports a UUID for a
module that doesn't match the build ID, but rather a hash of the .text
section (according to either of two different hash functions, used by
breakpad and Facebook respectively). The current logic searches for a
module by filename only to check the hash; this change updates it to
first search by directory+filename. This is important when the
directory specified in the minidump must be interpreted relative to a
user-provided sysoort, as the leaf directory won't be in the search path
in that case.
Also add a regression test; without this change, module validation fails
because we have just the placeholder module which reports as its path
the platform path in the minidump.
Reviewed By: clayborg
Differential Revision: https://reviews.llvm.org/D89155
XFAIL nodefaultlib.cpp on darwin - the test does not pass there
XFAIL TestGdbRemoteMemoryAllocation on windows - memory is allocated
with incorrect permissions
This patch adds support for the _M and _m gdb-remote packets, which
(de)allocate memory in the inferior. This works by "injecting" a
m(un)map syscall into the inferior. This consists of:
- finding an executable page of memory
- writing the syscall opcode to it
- setting up registers according to the os syscall convention
- single stepping over the syscall
The advantage of this approach over calling the mmap function is that
this works even in case the mmap function is buggy or unavailable. The
disadvantage is it is more platform-dependent, which is why this patch
only works on X86 (_32 and _64) right now. Adding support for other
linux architectures should be easy and consist of defining the
appropriate syscall constants. Adding support for other OSes depends on
the its ability to do a similar trick.
Differential Revision: https://reviews.llvm.org/D89124
Currently one can redefine a persistent variable and LLDB will just silently
ignore the second definition:
```
(lldb) expr int $i = 1
(lldb) expr int $i = 2
(lldb) expr $i
(int) $i = 1
```
This patch makes this an error and rejects the expression with the second
definition.
A nice follow up would be to refactor LLDB's persistent variables to not just be
a pair of type and name, but also contain some way to obtain the original
declaration and source code that declared the variable. That way we could
actually make a full diagnostic as we would get from redefining a variable twice
in the same expression.
Reviewed By: labath, shafik, JDevlieghere
Differential Revision: https://reviews.llvm.org/D89310
While debugging another bug I found out that we currently don't set any limit
for the number of diagnostics Clang emits. If a user does something that
generates a lot of errors (like including some long header file from within the
expression function), then we currently spam the LLDB output with potentially
thousands of Clang error diagnostics.
Clang sets a default limit of 20 errors, but given that LLDB is often used
interactively for small expressions I would say a limit of 5 is enough. The
limit is implemented as a setting, so if a user cares about seeing having a
million errors printed to their terminal then they can just increase the
settings value.
Reviewed By: shafik, mib
Differential Revision: https://reviews.llvm.org/D88889
This patch adds several build system targets that run the normal test suite but
against the Watch/TV/iPhone simulators.
Reviewed By: JDevlieghere
Differential Revision: https://reviews.llvm.org/D89224
Depends on D88841
As per the discussion in the RFC, we'll implement both
thread trace dump [instructions | functions]
This is the first step in implementing the "instructions" dumping command.
It includes:
- A minimal ProcessTrace plugin for representing processes from a trace file. I noticed that it was a required step to mimic how core-based processes are initialized, e.g. ProcessElfCore and ProcessMinidump. I haven't had the need to create ThreadTrace yet, though. So far HistoryThread seems good enough.
- The command handling itself in CommandObjectThread, which outputs a placeholder text instead of the actual instructions. I'll do that part in the next diff.
- Tests
{F13132325}
Differential Revision: https://reviews.llvm.org/D88769
With the feedback I was getting in different diffs, I realized that splitting the parsing logic into two classes was not easy to deal with. I do see value in doing that, but I'd rather leave that as a refactor after most of the intel-pt logic is in place. Thus, I'm merging the common parser into the intel pt one, having thus only one that is fully aware of Intel PT during parsing and object creation.
Besides, based on the feedback in https://reviews.llvm.org/D88769, I'm creating a ThreadIntelPT class that will be able to orchestrate decoding of its own trace and can handle the stop events correctly.
This leaves the TraceIntelPT class as an initialization class that glues together different components. Right now it can initialize a trace session from a json file, and in the future will be able to initialize a trace session from a live process.
Besides, I'm renaming SettingsParser to SessionParser, which I think is a better name, as the json object represents a trace session of possibly many processes.
With the current set of targets, we have the following
- Trace: main interface for dealing with trace sessions
- TraceIntelPT: plugin Trace for dealing with intel pt sessions
- TraceIntelPTSessionParser: a parser of a json trace session file that can create a corresponding TraceIntelPT instance along with Targets, ProcessTraces (to be created in https://reviews.llvm.org/D88769), and ThreadIntelPT threads.
- ProcessTrace: (to be created in https://reviews.llvm.org/D88769) can handle the correct state of the traces as the user traverses the trace. I don't think there'll be a need an intel-pt specific implementation of this class.
- ThreadIntelPT: a thread implementation that can handle the decoding of its own trace file, along with keeping track of the current position the user is looking at when doing reverse debugging.
Differential Revision: https://reviews.llvm.org/D88841
The problem here is in the "sliding" code in
ValueObjectChild::UpdateValue. It modifies m_bitfield_bit_offset and
m_value to ensure the bitfield value fits the window given by the
underlying type.
However, this is broken next time UpdateValue is called, because it
updates the m_value value from the parent. However, the value cannot be
slid again because the m_bitfield_bit_offset is already modified.
It seems this can happen only under specific circumstances. One way to
trigger is is to run an expression which can be interpreted (jitting it
causes a new StackFrame and ValueObject variables to be created).
I fix this bug by modifying m_byte_offset instead of m_scalar, and
ensuring the changes are folded into m_scalar regardless of how many
times UpdateValue is called.
Differential Revision: https://reviews.llvm.org/D88992
This patch fixes a few issues seen when running `ninja check-lldb` in a Release build with VS2017:
- Some binaries couldn't be found (such as lldb-vscode.exe), because .exe wasn't appended to the file name.
- Many tests used to fail since our installed locale is in French - the OS error messages are not emitted in English.
- Our codepage being Windows-1252, python failed to decode some error messages with accentuations.
Differential Revision: https://reviews.llvm.org/D88975
