Commit Graph

90 Commits

Author SHA1 Message Date
Michał Górny b6c24c1619 [lldb] [gdb-remote] Move ReadPacketWithOutputSupport() to client
Move ReadPacketWithOutputSupport() from GDBRemoteCommunication
to GDBRemoteClientBase.  This function is client-specific and moving
it there simplifies followup patches that split communication into
separate thread.

Sponsored by: The FreeBSD Foundation

Differential Revision: https://reviews.llvm.org/D135028
2022-10-03 18:42:49 +02:00
Michał Górny bdb4468d39 [gdb-remote] Move broadcasting logic down to GDBRemoteClientBase
Move the broadcasting support from GDBRemoteCommunication
to GDBRemoteClientBase since this is where it is actually used.  Remove
GDBRemoteCommunication and subclass constructor arguments left over
after Communication cleanup.

Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D133427
2022-09-09 17:13:08 +02:00
Michał Górny 9823d42557 [lldb] [Core] Split read thread support into ThreadedCommunication
Split the read thread support from Communication into a dedicated
ThreadedCommunication subclass.  The read thread support is used only
by a subset of Communication consumers, and it adds a lot of complexity
to the base class.  Furthermore, having a dedicated subclass makes it
clear whether a particular consumer needs to account for the possibility
of read thread being running or not.

The modules currently calling `StartReadThread()` are updated to use
`ThreadedCommunication`.  The remaining modules use the simplified
`Communication` class.

`SBCommunication` is changed to use `ThreadedCommunication` in order
to avoid changing the public API.

`CommunicationKDP` is updated in order to (hopefully) compile with
the new code.  However, I do not have a Darwin box to test it, so I've
limited the changes to the bare minimum.

`GDBRemoteCommunication` is updated to become a `Broadcaster` directly.
Since it does not inherit from `ThreadedCommunication`, its event
support no longer collides with the one used for read thread and can
be implemented cleanly.  The support for
`eBroadcastBitReadThreadDidExit` is removed from the code -- since
the read thread was not used, this event was never reported.

Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D133251
2022-09-06 13:09:42 +02:00
Michał Górny bc04d24085 [lldb] [llgs] Implement non-stop style stop notification packets
Implement the support for %Stop asynchronous notification packet format
in LLGS.  This does not implement full support for non-stop mode for
threaded programs -- process plugins continue stopping all threads
on every event.  However, it will be used to implement asynchronous
events in multiprocess debugging.

The non-stop protocol is enabled using QNonStop packet.  When it is
enabled, the server uses notification protocol instead of regular stop
replies.  Since all threads are always stopped, notifications are always
generated for all active threads and copied into stop notification
queue.

If the queue was empty, the initial asynchronous %Stop notification
is sent to the client immediately.  The client needs to (eventually)
acknowledge the notification by sending the vStopped packet, in which
case it is popped from the queue and the stop reason for the next thread
is reported.  This continues until notification queue is empty again,
in which case an OK reply is sent.

Asychronous notifications are also used for vAttach results and program
exits.  The `?` packet uses a hybrid approach -- it returns the first
stop reason synchronously, and exposes the stop reasons for remaining
threads via vStopped queue.

The change includes a test case for a program generating a segfault
on 3 threads.  The server is expected to generate a stop notification
for the segfaulting thread, along with the notifications for the other
running threads (with "no stop reason").  This verifies that the stop
reasons are correctly reported for all threads, and that notification
queue works.

Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.llvm.org/D125575
2022-06-21 19:04:20 +02:00
Pavel Labath d0810779b1 [lldb] Modernize ThreadLauncher
Accept a function object instead of a raw pointer. This avoids a bunch
of boilerplate typically needed to pass arguments to the thread
functions.

Differential Revision: https://reviews.llvm.org/D120321
2022-02-23 14:25:59 +01:00
Pavel Labath 6f82264dbb [lldb/gdb-remote] Remove more non-stop mode remnants
The read thread handling is completely dead code now that non-stop mode
no longer exists.
2021-11-24 10:00:43 +01:00
Michał Górny 4373f3595f [lldb] [Host] Move port predicate-related logic to gdb-remote
Remove the port predicate from Socket and ConnectionFileDescriptor,
and move it to gdb-remote.  It is specifically relevant to the threading
used inside gdb-remote and with the new port callback API, we can
reliably move it there.  While at it, switch from the custom Predicate
to std::promise/std::future.

Differential Revision: https://reviews.llvm.org/D112357
2021-10-26 13:53:08 +02:00
Michał Górny 3d3017d344 [lldb] [gdb-remote] Use standardized GDB errno values
GDB uses normalized errno values for vFile errors.  Implement
the translation between them and system errno values in the gdb-remote
plugin.

Differential Revision: https://reviews.llvm.org/D108148
2021-09-10 14:08:36 +02:00
Michał Górny 21e2d7ce43 [lldb] [gdb-remote] Implement fallback to vFile:stat for GetFileSize()
Implement a fallback to getting the file size via vFile:stat packet
when the remote server does not implement vFile:size.  This makes it
possible to query file sizes from remote gdbserver.

Note that unlike vFile:size, the fallback will not work if the server is
unable to open the file.

While at it, add a few tests for the 'platform get-size' command.

Differential Revision: https://reviews.llvm.org/D107780
2021-09-10 11:09:35 +02:00
Konrad Kleine eaebcbc679 [lldb] NFC remove DISALLOW_COPY_AND_ASSIGN
Summary:
This is how I applied my clang-tidy check (see
https://reviews.llvm.org/D80531) in order to remove
`DISALLOW_COPY_AND_ASSIGN` and have deleted copy ctors and deleted
assignment operators instead.

```
lang=bash
grep DISALLOW_COPY_AND_ASSIGN /opt/notnfs/kkleine/llvm/lldb -r -l | sort | uniq > files

for i in $(cat files);
do
  clang-tidy \
    --checks="-*,modernize-replace-disallow-copy-and-assign-macro" \
    --format-style=LLVM \
    --header-filter=.* \
    --fix \
    -fix-errors \
    $i;
done
```

Reviewers: espindola, labath, aprantl, teemperor

Reviewed By: labath, aprantl, teemperor

Subscribers: teemperor, aprantl, labath, emaste, sbc100, aheejin, MaskRay, arphaman, usaxena95, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D80543
2020-06-02 13:23:53 -04:00
Jonas Devlieghere 88fbd8f9e7 [lldb/Reproducers] Decode run-length encoding in GDB replay server.
The GDB replay server sanity-checks that every packet it receives
matches what it expects from the serialized packet log. This mechanism
tripped for TestReproducerAttach.py on Linux, because one of the packets
(jModulesInfo) uses run-length encoding. The replay server was comparing
the expanded incoming packet with the unexpanded packet in the log. As a
result, it claimed to have received an unexpected packet, which caused
the test to fail.

This patch addresses that issue by expanding the run-length encoding
before comparing the packets.

Differential revision: https://reviews.llvm.org/D76163
2020-03-16 08:47:39 -07:00
Jonas Devlieghere cdc514e4c6 [lldb] Update header guards to be consistent and compliant with LLVM (NFC)
LLDB has a few different styles of header guards and they're not very
consistent because things get moved around or copy/pasted. This patch
unifies the header guards across LLDB and converts everything to match
LLVM's style.

Differential revision: https://reviews.llvm.org/D74743
2020-02-17 23:15:40 -08:00
Eric Christopher 1d41d1bcdf Revert "Temporarily revert [lldb] e81268d - [lldb/Reproducers] Support multiple GDB remotes"
On multiple retry this issue won't duplicate - will revisit with author if
duplication works again.

This reverts commit c9e0b354e2.
2019-12-10 15:04:45 -08:00
Eric Christopher c9e0b354e2 Temporarily revert [lldb] e81268d - [lldb/Reproducers] Support multiple GDB remotes
This was causing a crash in opt+assert builds on linux and a follow-up
message was posted.

This reverts commit e81268d03e
2019-12-10 12:29:46 -08:00
Jonas Devlieghere e81268d03e [lldb/Reproducers] Support multiple GDB remotes
When running the test suite with always capture on, a handful of tests
are failing because they have multiple targets and therefore multiple
GDB remote connections. The current reproducer infrastructure is capable
of dealing with that.

This patch reworks the GDB remote provider to support multiple GDB
remote connections, similar to how the reproducers support shadowing
multiple command interpreter inputs. The provider now keeps a list of
packet recorders which deal with a single GDB remote connection. During
replay we rely on the order of creation to match the number of packets
to the GDB remote connection.

Differential revision: https://reviews.llvm.org/D71105
2019-12-10 11:16:52 -08:00
Fangrui Song efe8e7e36d typedef enum -> enum
Reviewed By: labath

Differential Revision: https://reviews.llvm.org/D61883

llvm-svn: 360654
2019-05-14 08:55:50 +00:00
Jonas Devlieghere 8b3af63b89 [NFC] Remove ASCII lines from comments
A lot of comments in LLDB are surrounded by an ASCII line to delimit the
begging and end of the comment.

Its use is not really consistent across the code base, sometimes the
lines are longer, sometimes they are shorter and sometimes they are
omitted. Furthermore, it looks kind of weird with the 80 column limit,
where the comment actually extends past the line, but not by much.
Furthermore, when /// is used for Doxygen comments, it looks
particularly odd. And when // is used, it incorrectly gives the
impression that it's actually a Doxygen comment.

I assume these lines were added to improve distinguishing between
comments and code. However, given that todays editors and IDEs do a
great job at highlighting comments, I think it's worth to drop this for
the sake of consistency. The alternative is fixing all the
inconsistencies, which would create a lot more churn.

Differential revision: https://reviews.llvm.org/D60508

llvm-svn: 358135
2019-04-10 20:48:55 +00:00
Raphael Isemann 46508f6f11 Refactor HAVE_LIBCOMPRESSION and related code in GDBRemoteCommunication
Summary:
The field `m_decompression_scratch_type` is only used when `HAVE_LIBCOMPRESSION` is
defined, which caused a warning which I fixed in rLLDB350675 by just marking the variable as always used.

This patch fixes this in a better way by only defining the variable (and the related `m_decompression_scratch`
variable) when `HAVE_LIBCOMPRESSION` is defined. This also required changing the way we handle
`HAVE_LIBCOMPRESSION` works, as this was previously always defined on macOS within the source file
but not in the header. Now it's always defined from within our config header when CMake defines it or when
we are on macOS.

The field initialization was moved to the header to prevent that we have `#ifdef` within our initializer list.

Reviewers: #lldb, jasonmolenda, sgraenitz, labath

Reviewed By: labath

Subscribers: labath, beanz, mgorny, lldb-commits, dblaikie

Differential Revision: https://reviews.llvm.org/D57011

llvm-svn: 352175
2019-01-25 08:21:47 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Jason Molenda 4a793c846f Force libcompression calls to be enabled when building on Darwin
systems.  It has been available in the OS over over three years
now.  If lldb doesn't link against -lcompression, it should be an
error.

Allocate a scratch buffer for libcompression to use when decoding
packets, instead of it having to allocate & free one on every call.

Fix a typeo with the size of the buffer that compression_decode_buffer()
is expanding into.

<rdar://problem/41601084> 

llvm-svn: 349563
2018-12-18 23:02:50 +00:00
Pavel Labath 181b823b04 Move Broadcaster+Listener+Event combo from Core into Utility
Summary:
These are general purpose "utility" classes, whose functionality is not
debugger-specific in any way. As such, I believe they belong in the
Utility module.

This doesn't break any particular dependency (yet), but it reduces the
number of Core dependencies across the board.

Reviewers: zturner, jingham, teemperor, clayborg

Subscribers: mgorny, lldb-commits

Differential Revision: https://reviews.llvm.org/D55361

llvm-svn: 349157
2018-12-14 15:59:49 +00:00
Jonas Devlieghere 9e046f02e3 Add GDB remote packet reproducer.
llvm-svn: 346780
2018-11-13 19:18:16 +00:00
Jonas Devlieghere ceff6644bb Remove header grouping comments.
This patch removes the comments grouping header includes. They were
added after running IWYU over the LLDB codebase. However they add little
value, are often outdates and burdensome to maintain.

llvm-svn: 346626
2018-11-11 23:17:06 +00:00
Raphael Isemann 7fae4932ad Move Predicate.h from Host to Utility
Summary:
This class was initially in Host because its implementation used to be
very OS-specific. However, with C++11, it has become a very simple
std::condition_variable wrapper, with no host-specific code.

It is also a general purpose utility class, so it makes sense for it to
live in a place where it can be used by everyone.

This has no effect on the layering right now, but it enables me to later
move the Listener+Broadcaster+Event combo to a lower layer, which is
important, as these are used in a lot of places (notably for launching a
process in Host code).

Reviewers: jingham, zturner, teemperor

Reviewed By: zturner

Subscribers: xiaobai, mgorny, lldb-commits

Differential Revision: https://reviews.llvm.org/D50384

llvm-svn: 341089
2018-08-30 17:51:10 +00:00
Pavel Labath 145d95c964 Move Args.cpp from Interpreter to Utility
Summary:
The Args class is used in plenty of places besides the command
interpreter (e.g., anything requiring an argc+argv combo, such as when
launching a process), so it needs to be in a lower layer. Now that the
class has no external dependencies, it can be moved down to the Utility
module.

This removes the last (direct) dependency from the Host module to
Interpreter, so I remove the Interpreter module from Host's dependency
list.

Reviewers: zturner, jingham, davide

Subscribers: mgorny, lldb-commits

Differential Revision: https://reviews.llvm.org/D45480

llvm-svn: 330200
2018-04-17 18:53:35 +00:00
Pavel Labath 9af71b3875 Move StringExtractorGDBRemote.h to the include folder
While trying to use this header I noticed that it is not in the include
folder. Move it to there and update all #includes to reference that file
correctly.

llvm-svn: 327996
2018-03-20 16:14:00 +00:00
Pavel Labath 7da84753a3 Handle O reply packets during qRcmd
Summary:
Gdb servers like openocd may send many $O reply packets for the client to output during a qRcmd command sequence.  Currently, lldb interprets the first O packet as an unexpected response.  Besides generating no output, this causes lldb to get out of sync with future commands because it continues reading O packets from the first command as response to subsequent commands.

This patch handles any O packets during an qRcmd, treating the first non-O packet as the true response.

Preliminary discussion at http://lists.llvm.org/pipermail/lldb-dev/2018-January/013078.html

Reviewers: clayborg

Reviewed By: clayborg

Subscribers: labath, lldb-commits

Differential Revision: https://reviews.llvm.org/D41745
Patch by Owen Shaw <llvm@owenpshaw.net>

llvm-svn: 322190
2018-01-10 14:39:08 +00:00
Pavel Labath 1ebc85f86f llgs-tests: Replace the "log+return false" pattern with llvm::Error
Summary:
These tests used to log the error message and return plain bool mainly
because at the time they we written, we did not have a nice way to
assert on llvm::Error values. That is no longer true, so replace this
pattern with a more idiomatic approach.

As a part of this patch, I also move the formatting of
GDBRemoteCommunication::PacketResult values out of the test code, as
that can be useful elsewhere.

Reviewers: zturner, eugene

Subscribers: mgorny, lldb-commits

Differential Revision: https://reviews.llvm.org/D39790

llvm-svn: 317795
2017-11-09 15:45:09 +00:00
Zachary Turner 97206d5727 Rename Error -> Status.
This renames the LLDB error class to Status, as discussed
on the lldb-dev mailing list.

A change of this magnitude cannot easily be done without
find and replace, but that has potential to catch unwanted
occurrences of common strings such as "Error".  Every effort
was made to find all the obvious things such as the word "Error"
appearing in a string, etc, but it's possible there are still
some lingering occurences left around.  Hopefully nothing too
serious.

llvm-svn: 302872
2017-05-12 04:51:55 +00:00
Greg Clayton 84577092ba Don't ever reduce the timeout of a packet, only increase it.
Differential Revision: https://reviews.llvm.org/D32087

llvm-svn: 300455
2017-04-17 16:20:22 +00:00
Pavel Labath c4063eee0d Introduce chrono to the Communication class
This replaces the raw integer timeout parameters in the class with their
chrono-based equivalents.  To achieve this, I have moved the Timeout class to a
more generic place and added a quick unit test for it.

llvm-svn: 287920
2016-11-25 11:58:44 +00:00
Pavel Labath 11b63cd309 Attempt to fix freebsd build after r287864
the chrono library there uses long long as the underlying chrono type, but
defines int64_t as long (or the other way around, I am not sure). In any case,
this caused the implicit conversion to not trigger. This should address that.

Also fix up the relevant unit test.

llvm-svn: 287867
2016-11-24 11:22:43 +00:00
Pavel Labath 1eff73c324 Introduce chrono to more gdb-remote functions
Summary:
This replaces the usage of raw integers with duration classes in the gdb-remote
packet management functions. The values are still converted back to integers once
they go into the generic Communication class -- that I am leaving to a separate
change.

The changes are mostly straight-forward (*), the only tricky part was
representation of infinite timeouts.

Currently, we use UINT32_MAX to denote infinite timeout. This is not well suited
for duration classes, as they tend to do arithmetic on the values, and the
identity of the MAX value can easily get lost (e.g.
microseconds(seconds(UINT32_MAX)).count() != UINT32_MAX). We cannot use zero to
represent infinity (as Listener classes do) because we already use it to do
non-blocking polling reads. For this reason, I chose to have an explicit value
for infinity.

The way I achieved that is via llvm::Optional, and I think it reads quite
natural. Passing llvm::None as "timeout" means "no timeout", while passing zero
means "poll". The only tricky part is this breaks implicit conversions (seconds
are implicitly convertible to microseconds, but Optional<seconds> cannot be
easily converted into Optional<microseconds>). For this reason I added a special
class Timeout, inheriting from Optional, and enabling the necessary conversions
one would normally expect.

(*) The other tricky part was GDBRemoteCommunication::PopPacketFromQueue, which
was needlessly complicated. I've simplified it, but that one is only used in
non-stop mode, and so is untested.

Reviewers: clayborg, zturner, jingham

Subscribers: lldb-commits

Differential Revision: https://reviews.llvm.org/D26971

llvm-svn: 287864
2016-11-24 10:54:49 +00:00
Pavel Labath 3aa049102f Remove usages of TimeValue from gdb-remote process plugin
Summary:
Most of the changes are very straight-forward, the only tricky part was the
"packet speed-test" function, which is very time-heavy. As the function was
completely untested, I added a quick unit smoke test for it.

Reviewers: clayborg, zturner

Subscribers: lldb-commits

Differential Revision: https://reviews.llvm.org/D25391

llvm-svn: 285602
2016-10-31 17:19:42 +00:00
Kate Stone b9c1b51e45 *** This commit represents a complete reformatting of the LLDB source code
*** to conform to clang-format’s LLVM style.  This kind of mass change has
*** two obvious implications:

Firstly, merging this particular commit into a downstream fork may be a huge
effort.  Alternatively, it may be worth merging all changes up to this commit,
performing the same reformatting operation locally, and then discarding the
merge for this particular commit.  The commands used to accomplish this
reformatting were as follows (with current working directory as the root of
the repository):

    find . \( -iname "*.c" -or -iname "*.cpp" -or -iname "*.h" -or -iname "*.mm" \) -exec clang-format -i {} +
    find . -iname "*.py" -exec autopep8 --in-place --aggressive --aggressive {} + ;

The version of clang-format used was 3.9.0, and autopep8 was 1.2.4.

Secondly, “blame” style tools will generally point to this commit instead of
a meaningful prior commit.  There are alternatives available that will attempt
to look through this change and find the appropriate prior commit.  YMMV.

llvm-svn: 280751
2016-09-06 20:57:50 +00:00
Zachary Turner 26709df81d Convert some functions to use StringRef instead of c_str, len
This started as an effort to change StringExtractor to store a
StringRef internally instead of a std::string.  I got that working
locally with just 1 test failure which I was unable to figure out the
cause of.  But it was also a massive changelist due to a trickle
down effect of changes.

So I'm starting over, using what I learned from the first time to
tackle smaller, more isolated changes hopefully leading up to
a full conversion by the end.

At first the changes (such as in this CL) will seem mostly
a matter of preference and pointless otherwise.  However, there
are some places in my larger CL where using StringRef turned 20+
lines of code into 2, drastically simplifying logic.  Hopefully
once these go in they will illustrate some of the benefits of
thinking in terms of StringRef.

llvm-svn: 279917
2016-08-27 15:52:29 +00:00
Pavel Labath 5a123c4e37 Remove GetThreadSuffixSupported from GDBRemoteCommunication **base** class
Despite its comment, the function is only used in the Client class, and its presence was merely
complicating mock implementation in unit tests.

llvm-svn: 278785
2016-08-16 09:36:29 +00:00
Greg Clayton c6c420fca1 Switch over to using socketpair for local debugserver connections as they are twice as fast as TCP sockets (on macOS at least).
This change opens a socket pair and passes the second socket pair file descriptor down to the debugserver binary using a new option: "--fd=N" where N is the file descriptor. This file descriptor gets passed via posix_spawn() so that there is no need to do any bind/listen or bind/accept calls and eliminates the hanshake unix socket that is used to pass the result of the actual port that ends up being used so it can save time on launch as well as being faster.

This is currently only enabled on __APPLE__ builds. Other OSs should try modifying the #define from ProcessGDBRemote.cpp but the first person will need to port the --fd option over to lldb-server. Any OSs that enable USE_SOCKETPAIR_FOR_LOCAL_CONNECTION in their native builds can use the socket pair stuff. The #define is Apple only right now, but looks like:

#if defined (__APPLE__)
#define USE_SOCKETPAIR_FOR_LOCAL_CONNECTION 1
#endif

<rdar://problem/27814880> 

llvm-svn: 278524
2016-08-12 16:46:18 +00:00
Pavel Labath 8c1b6bd7d2 Reapply "Rewrite gdb-remote's SendContinuePacketAndWaitForResponse"
Resumbitting the commit after fixing the following problems:
- broken unit tests on windows: incorrect gtest usage on my part (TEST vs. TEST_F)
- the new code did not correctly handle the case where we went to interrupt the process, but it
  stopped due to a different reason - the interrupt request would remain queued and would
  interfere with the following "continue". I also added a unit test for this case.

This reapplies r277156 and r277139.

llvm-svn: 278118
2016-08-09 12:04:46 +00:00
Pavel Labath 4cb699260c Revert "Rewrite gdb-remote's SendContinuePacketAndWaitForResponse"
This reverts commit r277139, because:
- broken unittest on windows (likely typo on my part)
- seems to break TestCallThatRestart (needs investigation)

llvm-svn: 277154
2016-07-29 15:41:52 +00:00
Pavel Labath e768c4b858 Rewrite gdb-remote's SendContinuePacketAndWaitForResponse
SendContinuePacketAndWaitForResponse was huge function with very complex interactions with
several other functions (SendAsyncSignal, SendInterrupt, SendPacket). This meant that making any
changes to how packet sending functions and threads interact was very difficult and error-prone.

This change does not add any functionality yet, it merely paves the way for future changes. In a
follow-up, I plan to add the ability to have multiple query packets in flight (i.e.,
request,request,response,response instead of the usual request,response sequences) and use that
to speed up qModuleInfo packet processing.

Here, I introduce two special kinds of locks: ContinueLock, which is used by the continue thread,
and Lock, which is used by everyone else. ContinueLock (atomically) sends a continue packet, and
blocks any other async threads from accessing the connection. Other threads create an instance of
the Lock object when they want to access the connection. This object, while in scope prevents the
continue from being send. Optionally, it can also interrupt the process to gain access to the
connection for async processing.

Most of the syncrhonization logic is encapsulated within these two classes. Some of it still
had to bleed over into the SendContinuePacketAndWaitForResponse, but the function is still much
more manageable than before -- partly because of most of the work is done in the ContinueLock
class, and partly because I have factored out a lot of the packet processing code separate
functions (this also makes the functionality more easily testable). Most importantly, there is
none of syncrhonization code in the async thread users -- as far as they are concerned, they just
need to declare a Lock object, and they are good to go (SendPacketAndWaitForResponse is now a
very thin wrapper around the NoLock version of the function, whereas previously it had over 100
lines of synchronization code).  This will make my follow up changes there easy.

I have written a number of unit tests for the new code and I have ran the test suite on linux and
osx with no regressions.

Subscribers: tberghammer

Differential Revision: https://reviews.llvm.org/D22629

llvm-svn: 277139
2016-07-29 13:10:02 +00:00
Saleem Abdulrasool 2d6a9ec935 Clean up vestigial remnants of locking primitives
This finally removes the use of the Mutex and Condition classes. This is an
intricate patch as the Mutex and Condition classes were tied together.
Furthermore, many places had slightly differing uses of time values. Convert
timeout values to relative everywhere to permit the use of
std::chrono::duration, which is required for the use of
std::condition_variable's timeout. Adjust all Condition and related Mutex
classes over to std::{,recursive_}mutex and std::condition_variable.

This change primarily comes at the cost of breaking the TracingMutex which was
based around the Mutex class. It would be possible to write a wrapper to
provide similar functionality, but that is beyond the scope of this change.

llvm-svn: 277011
2016-07-28 17:32:20 +00:00
Tamas Berghammer ccd6cffba3 Modify "platform connect" to connect to processes as well
The standard remote debugging workflow with gdb is to start the
application on the remote host under gdbserver (e.g.: gdbserver :5039
a.out) and then connect to it with gdb.

The same workflow is supported by debugserver/lldb-gdbserver with a very
similar syntax but to access all features of lldb we need to be
connected also to an lldb-platform instance running on the target.

Before this change this had to be done manually with starting a separate
lldb-platform on the target machine and then connecting to it with lldb
before connecting to the process.

This change modifies the behavior of "platform connect" with
automatically connecting to the process instance if it was started by
the remote platform. With this command replacing gdbserver in a gdb
based worflow is usually as simple as replacing the command to execute
gdbserver with executing lldb-platform.

Differential revision: http://reviews.llvm.org/D14952

llvm-svn: 255016
2015-12-08 14:08:19 +00:00
Eugene Zelenko edb35d95d1 Fix Clang-tidy modernize-use-override warnings in some files in source/Plugins; other minor fixes.
llvm-svn: 251167
2015-10-24 01:08:35 +00:00
Oleksiy Vyalov 9fe526c2e7 Add domain socket support to gdb-remote protocol and lldb-server.
http://reviews.llvm.org/D13881

llvm-svn: 250933
2015-10-21 19:34:26 +00:00
Greg Clayton 6988abc14d Allow LLDB.framework to locate debugserver even when it doesn't exist in the LLDB.framework.
This allows open source MacOSX clients to not have to build debugserver and the current LLDB can find debugserver inside the selected Xcode.app on your system.

<rdar://problem/23167253>

llvm-svn: 250735
2015-10-19 20:44:01 +00:00
Jason Molenda 91ffe0a570 Add a new wart, I mean feature, on to gdb-remote protocol: compression.
For some communication channels, sending large packets can be very 
slow.  In those cases, it may be faster to compress the contents of
the packet on the target device and decompress it on the debug host
system.  For instance, communicating with a device using something
like Bluetooth may be an environment where this tradeoff is a good one.

This patch adds a new field to the response to the "qSupported" packet
(which returns a "qXfer:features:" response) -- SupportedCompressions
and DefaultCompressionMinSize.  These tell you what the remote
stub can support.

lldb, if it wants to enable compression and can handle one of those 
algorithms, it can send a QEnableCompression packet specifying the
algorithm and optionally the minimum packet size to use compression
on.  lldb may have better knowledge about the best tradeoff for
a given communication channel.

I added support to debugserver an lldb to use the zlib APIs
(if -DHAVE_LIBZ=1 is in CFLAGS and -lz is in LDFLAGS) and the
libcompression APIs on Mac OS X 10.11 and later 
(if -DHAVE_LIBCOMPRESSION=1).  libz "zlib-deflate" compression.
libcompression can support deflate, lz4, lzma, and a proprietary
lzfse algorithm.  libcompression has been hand-tuned for Apple
hardware so it should be preferred if available.

debugserver currently only adds the SupportedCompressions when
it is being run on an Apple watch (TARGET_OS_WATCH).  Comment
that #if out from RNBRemote.cpp if you want to enable it to
see how it works.  I haven't tested this on a native system
configuration but surely it will be slower to compress & decompress
the packets in a same-system debug session.

I haven't had a chance to add support for this to 
GDBRemoteCommunciationServer.cpp yet.

<rdar://problem/21090180> 

llvm-svn: 240066
2015-06-18 21:46:06 +00:00
Ewan Crawford fab40d3911 Add Read Thread to GDBRemoteCommunication
In order to support asynchronous notifications for non-stop mode this patch adds a packet read thread. This is done by implementing AppendBytesToCache() from the communications class, which continually reads packets into a packet queue. To initialize this thread StartReadThread() must be called by the client, so since llgs and platform tools use the GBDRemoteCommunicatos code they must also call this function as well as ProcessGDBRemote.

When the read thread detects an async notify packet it broadcasts this event, where the matching listener will be added in the next non-stop patch.

Packets are now accessed by calling ReadPacket() which pops a packet from the queue, instead of using WaitForPacketWithTimeoutMicroSecondsNoLock()

Reviewers: vharron, clayborg

Subscribers: lldb-commits, labath, ted, domipheus, deepak2427 

Differential Revision: http://reviews.llvm.org/D10085

llvm-svn: 239824
2015-06-16 15:50:18 +00:00
Greg Clayton b30c50c8fa Add a new "qEcho" packet with the following format:
qEcho:%s

where '%s' is any valid string. The response to this packet is the exact packet itself with no changes, just reply with what you received!

This will help us to recover from packets timing out much more gracefully. Currently if a packet times out, LLDB quickly will hose up the debug session. For example, if we send a "abc" packet and we expect "ABC" back in response, but the "abc" command takes longer than the current timeout value this will happen:


--> "abc"
<-- <<<error: timeout>>>

Now we want to send "def" and get "DEF" back:

--> "def"
<-- "ABC"

We got the wrong response for the "def" packet because we didn't sync up with the server to clear any current responses from previously issues commands.

The fix is to modify GDBRemoteCommunication::WaitForPacketWithTimeoutMicroSecondsNoLock() so that when it gets a timeout, it syncs itself up with the client by sending a "qEcho:%u" where %u is an increasing integer, one for each time we timeout. We then wait for 3 timeout periods to sync back up. So the above "abc" session would look like:

--> "abc"
<-- <<<error: timeout>>> 1 second
--> "qEcho:1"
<-- <<<error: timeout>>> 1 second
<-- <<<error: timeout>>> 1 second
<-- "abc"
<-- "qEcho:1"

The first timeout is from trying to get the response, then we know we timed out and we send the "qEcho:1" packet and wait for 3 timeout periods to get back in sync knowing that we might actually get the response for the "abc" packet in the mean time...

In this case we would actually succeed in getting the response for "abc". But lets say the remote GDB server is deadlocked and will never response, it would look like:

--> "abc"
<-- <<<error: timeout>>> 1 second
--> "qEcho:1"
<-- <<<error: timeout>>> 1 second
<-- <<<error: timeout>>> 1 second
<-- <<<error: timeout>>> 1 second

We then disconnect and say we lost connection.

We might also have a bad GDB server that just dropped the "abc" packet on the floor. We can still recover in this case and it would look like:

--> "abc"
<-- <<<error: timeout>>> 1 second
--> "qEcho:1"
<-- "qEcho:1"

Then we know our remote GDB server is still alive and well, and it just dropped the "abc" response on the floor and we can continue to debug.

<rdar://problem/21082939>

llvm-svn: 238530
2015-05-29 00:01:55 +00:00
Ewan Crawford 9aa2da0025 Change ProcessGDBRemote last stop packet to a container.
In ProcessGDBRemote we currently have a single packet, m_last_stop_packet, used to set the thread stop info.
However in non-stop mode we can receive several stop reply packets in a sequence for different threads. As a result we need to use a container to hold them before they are processed.

This patch also changes the return type of CheckPacket() so we can detect async notification packets.

Reviewers: clayborg

Subscribers: labath, ted, deepak2427, lldb-commits

Differential Revision: http://reviews.llvm.org/D9853

llvm-svn: 238323
2015-05-27 14:12:34 +00:00