Summary:
A *.cpp file header in LLDB (and in LLDB) should like this:
```
//===-- TestUtilities.cpp -------------------------------------------------===//
```
However in LLDB most of our source files have arbitrary changes to this format and
these changes are spreading through LLDB as folks usually just use the existing
source files as templates for their new files (most notably the unnecessary
editor language indicator `-*- C++ -*-` is spreading and in every review
someone is pointing out that this is wrong, resulting in people pointing out that this
is done in the same way in other files).
This patch removes most of these inconsistencies including the editor language indicators,
all the different missing/additional '-' characters, files that center the file name, missing
trailing `===//` (mostly caused by clang-format breaking the line).
Reviewers: aprantl, espindola, jfb, shafik, JDevlieghere
Reviewed By: JDevlieghere
Subscribers: dexonsmith, wuzish, emaste, sdardis, nemanjai, kbarton, MaskRay, atanasyan, arphaman, jfb, abidh, jsji, JDevlieghere, usaxena95, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D73258
Summary:
This is the first of a few patches I have to improve the performance of dynamic module loading on Android.
In this first diff I'll describe the context of my main motivation and will then link to it in the other diffs to avoid repeating myself.
## Motivation
I have a few scenarios where opening a specific feature on an Android app takes around 40s when lldb is attached to it. The reason for that is because 40 modules are dynamicly loaded at that point in time and each one of them is taking ~1s.
## The problem
To learn about new modules we have a breakpoint on a linker function that is called twice whenever a module is loaded. One time just before it's loaded (so lldb can check which modules are loaded) and another right after it's loaded (so lldb can check again which ones are loaded and calculate the diference).
It's figuring out which modules are loaded that is taking quite some time. This is currently done by traversing the linked list of loaded shared libraries that the linker maintains in memory. Each item in the linked list requires its own `x` packet sent to the gdb server (this is android so the network also plays a part). In my scenario there are 400+ loaded libraries and even though we read 0x800 worth of bytes at a time we still make ~180 requests that end up taking 150-200ms.
We also do this twice, once before the module is loaded (state = eAdd) and another right after (state = eConsistent) which easly adds up to ~400ms per module.
## A solution
**Implement `xfer:libraries-svr4` in lldb-server:**
I noticed in the code that loads the new modules that it had support for the `xfer:libraries-svr4` packet (added ~4 years ago to support the ds2 debug server) but we didn't support it in lldb-server. This single packet returns an xml list of all the loaded modules by the process. The advantage is that there's no more need to make 180 requests to read the linked list. Additionally this new requests takes around 10ms.
**More efficient usage of the `xfer:libraries-svr4` packet in lldb:**
When `xfer:libraries-svr4` is available the Process class has a `LoadModules` function that requests this packet and then loads or unloads modules based on the current list of loaded modules by the process.
This is the function that is used by the DYLDRendezvous class to get the list of loaded modules before and after the module is loaded. However, this is really not needed since the LoadModules function already loaded or unloaded the modules accordingly. I changed this strategy to call LoadModules only once (after the process has loaded the module).
**Bugs**
I found a few issues in lldb while implementing this and have submitted independent patches for them.
I tried to devide this into multiple logical patches to make it easier to review and discuss.
## Tests
I wanted to put these set of diffs up before having all the tests up and running to start having them reviewed from a techical point of view. I'm also having some trouble making the tests running on linux so I need more time to make that happen.
# This diff
The `xfer` packages follow the same protocol, they are requested with `xfer:<object>:<read|write>:<annex>:<offset,length>` and a return that starts with `l` or `m` depending if the offset and length covers the entire data or not. Before implementing the `xfer:libraries-svr4` I refactored the `xfer:auxv` to generically handle xfer packets so we can easly add new ones.
The overall structure of the function ends up being:
* Parse the packet into its components: object, offset etc.
* Depending on the object do its own logic to generate the data.
* Return the data based on its size, the requested offset and length.
Reviewers: clayborg, xiaobai, labath
Reviewed By: labath
Subscribers: mgorny, krytarowski, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D62499
llvm-svn: 362982
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
This patch removes the comments following the header includes. They were
added after running IWYU over the LLDB codebase. However they add little
value, are often outdates and burdensome to maintain.
Differential revision: https://reviews.llvm.org/D54385
llvm-svn: 346625
This is intended as a clean up after the big clang-format commit
(r280751), which unfortunately resulted in many of the comment
paragraphs in LLDB being very hard to read.
FYI, the script I used was:
import textwrap
import commands
import os
import sys
import re
tmp = "%s.tmp"%sys.argv[1]
out = open(tmp, "w+")
with open(sys.argv[1], "r") as f:
header = ""
text = ""
comment = re.compile(r'^( *//) ([^ ].*)$')
special = re.compile(r'^((([A-Z]+[: ])|([0-9]+ )).*)|(.*;)$')
for line in f:
match = comment.match(line)
if match and not special.match(match.group(2)):
# skip intentionally short comments.
if not text and len(match.group(2)) < 40:
out.write(line)
continue
if text:
text += " " + match.group(2)
else:
header = match.group(1)
text = match.group(2)
continue
if text:
filled = textwrap.wrap(text, width=(78-len(header)),
break_long_words=False)
for l in filled:
out.write(header+" "+l+'\n')
text = ""
out.write(line)
os.rename(tmp, sys.argv[1])
Differential Revision: https://reviews.llvm.org/D46144
llvm-svn: 331197
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
Summary:
This patch adds support for sending strings along with
error codes in the reply packets. The implementation is
based on the feedback recieved in the lldb-dev mailing
list. The patch also adds an extra packet for the client
to query if the server has the capability to provide
strings along with error replys.
Reviewers: labath, jingham, sas, lldb-commits, clayborg
Reviewed By: labath, clayborg
Differential Revision: https://reviews.llvm.org/D34945
llvm-svn: 307768
Summary:
The changes consist of new packets for trace manipulation and
trace collection. The new packets are also documented. The packets
are capable of providing custom trace specific parameters to start
tracing and also retrieve such configuration from the server.
Reviewers: clayborg, lldb-commits, tberghammer, labath, zturner
Reviewed By: clayborg, labath
Subscribers: krytarowski, lldb-commits
Differential Revision: https://reviews.llvm.org/D32585
llvm-svn: 303972
This patch makes adjustments to header file includes in
lldbUtility based on recommendations by the iwyu tool
(include-what-you-use). The goal here is to make sure that
all files include the exact set of headers which are needed
for that file only, to eliminate cases of dead includes (e.g.
someone deleted some code but forgot to delete the header
includes that that code necessitated), and to eliminate the
case where header includes are picked up transitively.
llvm-svn: 299676
Summary: QPassSignals package allows lldb client to tell lldb-server to ignore certain types of signals and re-inject them back to inferior without stopping execution.
Reviewers: jmajors, labath
Subscribers: danalbert, srhines, emaste, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D30286
Author: Eugene Zemtsov <ezemtsov@google.com>
llvm-svn: 296101
Summary:
This adds the jModulesInfo packet, which is the equivalent of qModulesInfo, but it enables us to
query multiple modules at once. This makes a significant speed improvement in case the
application has many (over a hundred) modules, and the communication link has a non-negligible
latency. This functionality is accessed by ProcessGdbRemote::PrefetchModuleSpecs(), which does
the caching. GetModuleSpecs() is modified to first consult the cache before asking the remote
stub. PrefetchModuleSpecs is currently only called from POSIX-DYLD dynamic loader plugin, after
it reads the list of modules from the inferior memory, but other uses are possible.
This decreases the attach time to an android application by about 40%.
Reviewers: clayborg
Subscribers: tberghammer, lldb-commits, danalbert
Differential Revision: https://reviews.llvm.org/D24236
llvm-svn: 280919
*** 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
rnb_err_t
RNBRemote::HandlePacket_stop_process (const char *p)
{
if (!DNBProcessInterrupt(m_ctx.ProcessID()))
HandlePacket_last_signal (NULL);
return rnb_success;
}
In the call to DNBProcessInterrupt we did:
nub_bool_t
DNBProcessInterrupt(nub_process_t pid)
{
MachProcessSP procSP;
if (GetProcessSP (pid, procSP))
return procSP->Interrupt();
return false;
}
This would always return false. It would cause HandlePacket_stop_process to always call "HandlePacket_last_signal (NULL);" which would send an extra stop reply packet _if_ the process is stopped. On a machine with enough cores, it would call DNBProcessInterrupt(...) and then HandlePacket_last_signal(NULL) so quickly that it will never send out an extra stop reply packet. But if the machine is slow enough or doesn't have enough cores, it could cause the call to HandlePacket_last_signal() to actually succeed and send an extra stop reply packet. This would cause problems up in GDBRemoteCommunicationClient::SendContinuePacketAndWaitForResponse() where it would get the first stop reply packet and then possibly return or execute an async packet. If it returned, then the next packet that was sent will get the second stop reply as its response. If it executes an async packet, the async packet will get the wrong response.
To fix this I did the following:
1 - in debugserver, I fixed "bool MachProcess::Interrupt()" to return true if it sends the signal so we avoid sending the stop reply twice on slower machines
2 - Added a log line to RNBRemote::HandlePacket_stop_process() to say if we ever send an extra stop reply so we will see this in the darwin console output if this does happen
3 - Added response validators to StringExtractorGDBRemote so that we can verify some responses to some packets.
4 - Added validators to packets that often follow stop reply packets like the "m" packet for memory reads, JSON packets since "jThreadsInfo" is often sent immediately following a stop reply.
5 - Modified GDBRemoteCommunicationClient::SendPacketAndWaitForResponseNoLock() to validate responses. Any "StringExtractorGDBRemote &response" that contains a valid response verifier will verify the response and keep looking for correct responses up to 3 times. This will help us get back on track if we do get extra stop replies. If a StringExtractorGDBRemote does not have a response validator, it will accept any packet in response.
6 - In GDBRemoteCommunicationClient::SendPacketAndWaitForResponse we copy the response validator from the "response" argument over into m_async_response so that if we send the packet by interrupting the running process, we can validate the response we actually get in GDBRemoteCommunicationClient::SendContinuePacketAndWaitForResponse()
7 - Modified GDBRemoteCommunicationClient::SendContinuePacketAndWaitForResponse() to always check for an extra stop reply packet for 100ms when the process is interrupted. We were already doing this because we might interrupt a process with a \x03 packet, yet the process was in the process of stopping due to another reason. This race condition could cause an extra stop reply packet because the GDB remote protocol says if a \x03 packet is sent while the process is stopped, we should send a stop reply packet back. Now we always check for an extra stop reply packet when we manually interrupt a process.
The issue was showing up when our IDE would attempt to set a breakpoint while the process is running and this would happen:
--> \x03
<-- $T<stop reply 1>
--> z0,AAAAA,BB (set breakpoint)
<-- $T<stop reply 1> (incorrect extra stop reply packet)
--> c
<-- OK (response from z0 packet)
Now all packet traffic was off by one response. Since we now have a validator on the response for "z" packets, we do this:
--> \x03
<-- $T<stop reply 1>
--> z0,AAAAA,BB (set breakpoint)
<-- $T<stop reply 1> (Ignore this because this can't be the response to z0 packets)
<-- OK -- (we are back on track as this is a valid response to z0)
...
As time goes on we should add more packet validators.
<rdar://problem/22859505>
llvm-svn: 265086
The standard remote debugging workflow with gdb is to start the
application on the remote host under gdbserver (e.g.: gdbserver :5039
a.out) and then connect to it with gdb.
The same workflow is supported by debugserver/lldb-gdbserver with a very
similar syntax but to access all features of lldb we need to be
connected also to an lldb-platform instance running on the target.
Before this change this had to be done manually with starting a separate
lldb-platform on the target machine and then connecting to it with lldb
before connecting to the process.
This change modifies the behavior of "platform connect" with
automatically connecting to the process instance if it was started by
the remote platform. With this command replacing gdbserver in a gdb
based worflow is usually as simple as replacing the command to execute
gdbserver with executing lldb-platform.
Differential revision: http://reviews.llvm.org/D14952
llvm-svn: 255016
Summary:
This commit adds support for binary memory reads ($x) to lldb-server. It also removes the "0x"
prefix from the $x client packet, to make it more compatible with the old $m packet. This allows
us to use almost the same code for handling both packet types. I have verified that debugserver
correctly handles $x packets even without the leading "0x". I have added a test which verifies
that the stub returns the same memory contents for both kinds of memory reads ($x and $m).
Reviewers: tberghammer, jasonmolenda
Subscribers: iancottrell, lldb-commits
Differential Revision: http://reviews.llvm.org/D13695
llvm-svn: 250295
Summary:
This commit adds initial support for the jThreadsInfo packet to lldb-server. The current
implementation does not expedite inferior memory. I have also added a description of the new
packet to our protocol documentation (mostly taken from Greg's earlier commit message).
Reviewers: clayborg, ovyalov, tberghammer
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D11187
llvm-svn: 242402
Summary:
- Consolidate Unix signals selection in UnixSignals.
- Make Unix signals available from platform.
- Add jSignalsInfo packet to retrieve Unix signals from remote platform.
- Get a copy of the platform signal for each remote process.
- Update SB API for signals.
- Update signal utility in test suite.
Reviewers: ovyalov, clayborg
Subscribers: chaoren, jingham, labath, emaste, tberghammer, lldb-commits
Differential Revision: http://reviews.llvm.org/D11094
llvm-svn: 242101