.. from the guts of GDBRemoteCommunication to ~top level.
This is motivated by #131519 and by the fact that's impossible to guess
whether the author of a symlink intended it to be a "convenience
shortcut" -- meaning it should be resolved before looking for related
files; or an "implementation detail" -- meaning the related files should
be located near the symlink itself.
This debate is particularly ridiculous when it comes to lldb-server
running in platform mode, because it also functions as a debug server,
so what we really just need to do is to pass /proc/self/exe in a
platform-independent manner.
Moving the location logic higher up achieves that as lldb-platform (on
non-macos) can pass `HostInfo::GetProgramFileSpec`, while liblldb can
use the existing complex logic (which only worked on liblldb anyway as
lldb-platform doesn't have a lldb_private::Platform instance).
Another benefit of this patch is a reduction in dependency from
GDBRemoteCommunication to the rest of liblldb (achieved by avoiding the
Platform dependency).
It's not necessary on posix platforms as of #126935 and it's ignored on
windows as of #138896. For both platforms, we have a better way of
inheriting FDs/HANDLEs.
This fixes issues found in e066f35c6981c720e3a7e5883efc40c861b3b7, which
was later reverted. The problem was with "k" message which was sent with
sync_on_timeout flag set to true, so lldb was waiting for response,
which is currently not being sent by lldb-server. Not waiting for
response at all seems to be not a solution, because on MAC OS X lldb
waits for response from "k" to gracefully kill inferior.
The function was extremely messy in that it, depending on the set of
arguments, it could either modify the Connection object in `this` or
not. It had a lot of arguments, with each call site passing a different
combination of null values. This PR:
- packs "url" and "comm_fd" arguments into a variant as they are
mutually exclusive
- removes the (surprising) "null url *and* null comm_fd" code path which
is not used as of https://github.com/llvm/llvm-project/pull/145017
- marks the function as `static` to make it clear it (now) does not
operate on the `this` object.
Depends on #145017
Originally added for reproducers, it is now only used for test code.
While we could make it a test helper, I think that after #145015 it is
simple enough to not be needed.
Also squeeze in a change to make ConnectionFileDescriptor accept a
unique_ptr<Socket>.
It creates a pair of connected sockets using the simplest mechanism for
the given platform (TCP on windows, socketpair(2) elsewhere).
Main motivation is to remove the ugly platform-specific code in
ProcessGDBRemote::LaunchAndConnectToDebugserver, but it can also be used
in other places where we need to create a pair of connected sockets.
Patch fixes the sync-on-timeout logic in lldb and switches to qEcho
based ping, instead of qC. This fixes vRun message case, when there is
no process yet and qC returns an error.
This reverts commit
a0260a95ec,
reapplying
7c5f5f3ef8,
with a fix that makes *both*
pipe handles inheritable.
The original commit description was:
This is a follow-up to https://github.com/llvm/llvm-project/pull/126935,
which enables passing handles to a child
process on windows systems. Unlike on unix-like systems, the handles
need to be created with the "inheritable" flag because there's to way to
change the flag value after it has been created. This is why I don't
respect the child_process_inherit flag but rather always set the flag to
true. (My next step is to delete the flag entirely.)
This does mean that pipe may be created as inheritable even if its not
necessary, but I think this is offset by the fact that windows (unlike
unixes, which pass all ~O_CLOEXEC descriptors through execve and *all*
descriptors through fork) has a way to specify the precise set of
handles to pass to a specific child process.
If this turns out to be insufficient, instead of a constructor flag, I'd
rather go with creating a separate api to create an inheritable copy of
a handle (as typically, you only want to inherit one end of the pipe).
This is a follow-up to https://github.com/llvm/llvm-project/pull/126935,
which enables passing handles to a child
process on windows systems. Unlike on unix-like systems, the handles
need to be created with the "inheritable" flag because there's to way to
change the flag value after it has been created. This is why I don't
respect the child_process_inherit flag but rather always set the flag to
true. (My next step is to delete the flag entirely.)
This does mean that pipe may be created as inheritable even if its not
necessary, but I think this is offset by the fact that windows (unlike
unixes, which pass all ~O_CLOEXEC descriptors through execve and *all*
descriptors through fork) has a way to specify the precise set of
handles to pass to a specific child process.
If this turns out to be insufficient, instead of a constructor flag, I'd
rather go with creating a separate api to create an inheritable copy of
a handle (as typically, you only want to inherit one end of the pipe).
- use early exits where possible
- avoid the listen thread by using Socket APIs which allow separate
"listen" and "accept" steps
- use formatv-like log statements
There "should" be no functional changes from this patch.
I *think* this was the reason behind the failures in
2fd860c1f559c0b0be66cc000e38270a04d0a1a3: the clang include tool showed
the Config.h headers as unused, and because the macro was referenced
through an `#ifdef`, its removal didn't cause build failures. Switching
to `#cmakedefine01` + `#if` should make sure this does not happen again.
According to D48977, the `#ifndef`+`#cmakedefine` patterns is due to
some files redefining the macro themselves. I no longer see any such
files in the source tree (there also were no files like that in the
source tree at the revision mentioned, but the macro *was* defined in
the hand-maintained XCode project we had at the time).
This reverts commit 68ab45f0533f3bbfc1c96bddd53de7e769180219, reapplying
2fd860c1f559c0b0be66cc000e38270a04d0a1a3. The only change is keeping
"lldb/Host/Config.h", which I believe was the cause of the failures.
The main motivation for this was the inconsistency in handling of
partial reads/writes between the windows and posix implementations
(windows was returning partial reads, posix was trying to fill the
buffer completely). I settle on the windows implementation, as that's
the more common behavior, and the "eager" version can be implemented on
top of that (in most cases, it isn't necessary, since we're writing just
a single byte).
Since this also required auditing the callers to make sure they're
handling partial reads/writes correctly, I used the opportunity to
modernize the function signatures as a forcing function. They now use
the `Timeout` class (basically an `optional<duration>`) to support both
polls (timeout=0) and blocking (timeout=nullopt) operations in a single
function, and use an `Expected` instead of a by-ref result to return the
number of bytes read/written.
As a drive-by, I also fix a problem with the windows implementation
where we were rounding the timeout value down, which meant that calls
could time out slightly sooner than expected.
It's never set to true. Also, using inheritable FDs in a multithreaded
process pretty much guarantees descriptor leaks. It's better to
explicitly pass a specific FD to a specific subprocess, which we already
mostly can do using the ProcessLaunchInfo FileActions.
Allows us to stop waiting for a connection if it doesn't come in a
certain amount of time. Right now, I'm keeping the status quo (infitnite
wait) in the "production" code, but using smaller (finite) values in
tests. (A lot of these tests create "loopback" connections, where a
really short wait is sufficient: on linux at least even a poll (0s wait)
is sufficient if the other end has connect()ed already, but this doesn't
seem to be the case on Windows, so I'm using a 1s wait in these cases).
(this is lldb part)
Without these explicit includes, removing other headers, who implicitly
include llvm-config.h, may have non-trivial side effects. For example,
`clangd` may report even `llvm-config.h` as "no used" in case it defines
a macro, that is explicitly used with #ifdef. It is actually amplified
with different build configs which use different set of macros.
This patch removes all of the Set.* methods from Status.
This cleanup is part of a series of patches that make it harder use the
anti-pattern of keeping a long-lives Status object around and updating
it while dropping any errors it contains on the floor.
This patch is largely NFC, the more interesting next steps this enables
is to:
1. remove Status.Clear()
2. assert that Status::operator=() never overwrites an error
3. remove Status::operator=()
Note that step (2) will bring 90% of the benefits for users, and step
(3) will dramatically clean up the error handling code in various
places. In the end my goal is to convert all APIs that are of the form
` ResultTy DoFoo(Status& error)
`
to
` llvm::Expected<ResultTy> DoFoo()
`
How to read this patch?
The interesting changes are in Status.h and Status.cpp, all other
changes are mostly
` perl -pi -e 's/\.SetErrorString/ = Status::FromErrorString/g' $(git
grep -l SetErrorString lldb/source)
`
plus the occasional manual cleanup.
MAX_PATH is definitely larger than 6 bytes we are expecting for this
message, and could be rather large depending on the target OS (4K for
some Linux OSs).
Since the buffer gets allocated on the stack we better be conservative
and allocate what we actually need.
The `else if` condition for checking `m_compression_type` is redundant
as it matches with a previous `if` condition, making the expression
always false. Reported by cppcheck as a possible cut-and-paste error.
Caught by cppcheck -
lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp:543:35:
style: Expression is always false because 'else if' condition matches
previous condition at line 535. [multiCondition]
Fix#91222
StreamFile subclasses Stream (from lldbUtility) and is backed by a File
(from lldbHost). It does not depend on anything from lldbCore or any of its
sibling libraries, so I think it makes sense for this to live in
lldbHost instead.
Differential Revision: https://reviews.llvm.org/D157460
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
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
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
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
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
Although I cannot find any mention of this in the specification, both
gdb and lldb agree on sending an initial + packet after establishing the
connection.
OTOH, gdbserver and lldb-server behavior is subtly different. While
lldb-server *expects* the initial ack, and drops the connection if it is
not received, gdbserver will just ignore a spurious ack at _any_ point
in the connection.
This patch changes lldb's behavior to match that of gdb. An ACK packet
is ignored at any point in the connection (except when expecting an ACK
packet, of course). This is inline with the "be strict in what you
generate, and lenient in what you accept" philosophy, and also enables
us to remove some special cases from the server code. I've extended the
same handling to NAK (-) packets, mainly because I don't see a reason to
treat them differently here.
(The background here is that we had a stub which was sending spurious
+ packets. This bug has since been fixed, but I think this change makes
sense nonetheless.)
Differential Revision: https://reviews.llvm.org/D114520
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
Add a Communication::WriteAll() that resumes Write() if the initial call
did not write all data. Use it in GDBRemoteCommunication when sending
packets in order to fix handling partial writes (i.e. just resume/retry
them rather than erring out). This fixes LLDB failures when writing
large packets to a pty.
Differential Revision: https://reviews.llvm.org/D112169
Replace misc. StringConvert uses with llvm::to_integer()
and llvm::to_float(), except for cases where further refactoring is
planned. The purpose of this change is to eliminate the StringConvert
API that is duplicate to LLVM, and less correct in behavior at the same
time.
Differential Revision: https://reviews.llvm.org/D110447
The C headers are deprecated so as requested in D102845, this is replacing them
all with their (not deprecated) C++ equivalent.
Reviewed By: shafik
Differential Revision: https://reviews.llvm.org/D103084
