Commit Graph

31 Commits

Author SHA1 Message Date
Jonas Devlieghere 3b4db10f34
[lldb] Actually support more than 32 logging categories
In January, Greg put up a patch (D117382) to support, among other
things, more than 32 log categories. That led to a bunch of nice
cleanups, but categories remained constrained because different parts of
the code were still using uint32_t. This patch fixes the remaining
issues and makes it possible to add a 32nd log category.

Differential revision: https://reviews.llvm.org/D134245
2022-09-19 22:31:20 -07:00
Jonas Devlieghere 9bdb7e5734
[lldb] Add a log dump command
Add a log dump command to dump logs to a file. This only works for
channels that have a log handler associated that supports dumping. For
now that's limited to the circular log handler, but more could be added
in the future.

Differential revision: https://reviews.llvm.org/D128557
2022-06-27 10:02:34 -07:00
Jonas Devlieghere 70841b97eb
[lldb] Make thread safety the responsibility of the log handlers
Drop the thread-safe flag and make the locking strategy the
responsibility of the individual log handler.

Previously we got away with a non-thread safe mode because we were using
unbuffered streams that rely on the underlying syscalls/OS for
synchronization. With the introduction of log handlers, we can have
arbitrary logic involved in writing out the logs. With this patch the
log handlers can pick the most appropriate locking strategy for their
particular implementation.

Differential revision: https://reviews.llvm.org/D127922
2022-06-23 09:12:05 -07:00
Jonas Devlieghere 09dea54669
[lldb] Support a buffered logging mode
This patch adds a buffered logging mode to lldb. A buffer size can be
passed to `log enable` with the -b flag. If no buffer size is specified,
logging is unbuffered.

Differential revision: https://reviews.llvm.org/D127986
2022-06-23 09:12:01 -07:00
Jonas Devlieghere de74756571
[lldb] Remove LogHandler::Create functions (NFC)
Remove the LogHandler::Create functions. Except for the StreamHandler
they were just forwarding their arguments to std::make_shared.
2022-06-16 21:04:08 -07:00
Jonas Devlieghere 6ac608b3d8
[lldb] Add RotatingLogHandler
Add a log handler that maintains a circular buffer with a fixed size.

Differential revision: https://reviews.llvm.org/D127937
2022-06-16 15:17:40 -07:00
Jonas Devlieghere 6ff49af33d
[lldb] Introduce the concept of a log handler (NFC)
This patch introduces the concept of a log handlers. Log handlers allow
customizing the way log output is emitted. The StreamCallback class
tried to do something conceptually similar. The benefit of the log
handler interface is that you don't need to conform to llvm's
raw_ostream interface.

Differential revision: https://reviews.llvm.org/D127922
2022-06-16 13:34:28 -07:00
Pavel Labath c34698a811 [lldb] Rename Logging.h to LLDBLog.h and clean up includes
Most of our code was including Log.h even though that is not where the
"lldb" log channel is defined (Log.h defines the generic logging
infrastructure). This worked because Log.h included Logging.h, even
though it should.

After the recent refactor, it became impossible the two files include
each other in this direction (the opposite inclusion is needed), so this
patch removes the workaround that was put in place and cleans up all
files to include the right thing. It also renames the file to LLDBLog to
better reflect its purpose.
2022-02-03 14:47:01 +01:00
Pavel Labath 0f08db66db [lldb] Make logging machinery type-safe
This patch makes use of c++ type checking and scoped enums to make
logging statements shorter and harder to misuse.

Defines like LIBLLDB_LOG_PROCESS are replaces with LLDBLog::Process.
Because it now carries type information we do not need to worry about
matching a specific enum value with the right getter function -- the
compiler will now do that for us.

The main entry point for the logging machinery becomes the GetLog
(template) function, which will obtain the correct Log object based on
the enum type. It achieves this through another template function
(LogChannelFor<T>), which must be specialized for each type, and should
return the appropriate channel object.

This patch also removes the ability to log a message if multiple
categories are enabled simultaneously as it was unused and confusing.

This patch does not actually remove any of the existing interfaces. The
defines and log retrieval functions are left around as wrappers around
the new interfaces. They will be removed in follow-up patch.

Differential Revision: https://reviews.llvm.org/D117490
2022-01-25 12:13:49 +01:00
Pavel Labath caa7e765e5 [lldb] Make ProcessLauncherPosixFork (mostly) async-signal-safe
Multithreaded applications using fork(2) need to be extra careful about
what they do in the fork child. Without any special precautions (which
only really work if you can fully control all threads) they can only
safely call async-signal-safe functions. This is because the forked
child will contain snapshot of the parents memory at a random moment in
the execution of all of the non-forking threads (this is where the
similarity with signals comes in).

For example, the other threads could have been holding locks that can
now never be released in the child process and any attempt to obtain
them would block. This is what sometimes happen when using tcmalloc --
our fork child ends up hanging in the memory allocation routine. It is
also what happened with our logging code, which is why we added a
pthread_atfork hackaround.

This patch implements a proper fix to the problem, by which is to make
the child code async-signal-safe. The ProcessLaunchInfo structure is
transformed into a simpler ForkLaunchInfo representation, one which can
be read without allocating memory and invoking complex library
functions.

Strictly speaking this implementation is not async-signal-safe, as it
still invokes library functions outside of the posix-blessed set of
entry points. Strictly adhering to the spec would mean reimplementing a
lot of the functionality in pure C, so instead I rely on the fact that
any reasonable implementation of some functions (e.g.,
basic_string::c_str()) will not start allocating memory or doing other
unsafe things.

The new child code does not call into our logging infrastructure, which
enables us to remove the pthread_atfork call from there.

Differential Revision: https://reviews.llvm.org/D116165
2021-12-29 09:45:47 +01:00
Martin Storsjö e50f9c419a [lldb] Rename StringRef _lower() method calls to _insensitive() 2021-06-25 00:22:01 +03:00
Raphael Isemann 76e47d4887 [lldb][NFC] Use C++ versions of the deprecated C standard library headers
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
2021-05-26 12:46:12 +02:00
Benjamin Kramer adcd026838 Make llvm::StringRef to std::string conversions explicit.
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.

This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.

This doesn't actually modify StringRef yet, I'll do that in a follow-up.
2020-01-28 23:25:25 +01:00
Raphael Isemann 808142876c [lldb][NFC] Fix all formatting errors in .cpp file headers
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
2020-01-24 08:52:55 +01:00
Raphael Isemann 8126340b3f [lldb] Fix log output and UtilityTests/LogChannelTest.List
I refactored this code in 372691 and it seems I didn't fully
replicate the original log output, so that test was failing.

llvm-svn: 372696
2019-09-24 08:20:05 +00:00
Raphael Isemann 6ba63d8851 [lldb] Add completion support for log enable/disable/list
Reviewers: #lldb, JDevlieghere

Reviewed By: JDevlieghere

Subscribers: JDevlieghere, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D67903

llvm-svn: 372691
2019-09-24 07:18:09 +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
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
Jonas Devlieghere 672d2c1255 Remove comments after header includes.
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
2018-11-11 23:16:43 +00:00
Tatyana Krasnukha 0b8bea311f Adjust thread name column width depending on real name length.
Make 16-byte aligned field instead of truncating a name to 16 byte.

llvm-svn: 336993
2018-07-13 11:49:28 +00:00
Adrian Prantl 05097246f3 Reflow paragraphs in comments.
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
2018-04-30 16:49:04 +00:00
Nico Weber b1cb0b7957 s/LLVM_ON_WIN32/_WIN32/, lldb
LLVM_ON_WIN32 is set exactly with MSVC and MinGW (but not Cygwin) in            
HandleLLVMOptions.cmake, which is where _WIN32 defined too.  Just use the        
default macro instead of a reinvented one.                                      
                                                                                
See thread "Replacing LLVM_ON_WIN32 with just _WIN32" on llvm-dev and cfe-dev.  
No intended behavior change.

llvm-svn: 329697
2018-04-10 13:33:45 +00:00
Pavel Labath d2aab749d1 Log: delimit thread name in log message
The thread name was not followed by a space, which meant it was glued to
the log message. I also align the name as we do that with other log
fields. I align it to 16 chars instead of llvm::max_thread_name(), as
that can be 64 on darwin, which is rather long. If anybody feels
differently about that, we can change it.

llvm-svn: 317679
2017-11-08 10:48:54 +00:00
Pavel Labath d813309e03 Logging: Disable logging after fork()
Summary:
We had a bug where if we had forked (in the ProcessLauncherPosixFork)
while another thread was writing a log message, we would deadlock. This
happened because the fork child inherited the locked log rwmutex, which
would never get unlocked. This meant the child got stuck trying to
disable all log channels.

The bug existed for a while but only started being apparent after
D37930, which started using ThreadLauncher (which uses logging) instead
of std::thread (which does not) for launching TaskPool threads.

The fix is to use pthread_atfork to disable logging in the forked child.

Reviewers: zturner, eugene, clayborg

Subscribers: lldb-commits

Differential Revision: https://reviews.llvm.org/D38938

llvm-svn: 316368
2017-10-23 19:41:17 +00:00
Pavel Labath 6858988df3 Revert "Logging: Make sure logging machinery is in a consistent state after forking"
The pthread_atfork trick breaks on android, because
pthread_rwlock_unlock detects that it is not the same thread which
locked the lock. This means that the subsequent lock attempt will still
deadlock (only this time it happens deterministically instead of at
random). Reverting to find a better solution.

This reverts commit r316173.

llvm-svn: 316231
2017-10-20 19:44:53 +00:00
Pavel Labath 6c3c02a3bd Logging: Make sure logging machinery is in a consistent state after forking
Summary:
We had a bug where if we had forked (in the ProcessLauncherPosixFork)
while another thread was writing a log message, we would deadlock. This
happened because the fork child inherited the locked log rwmutex, which
would never get unlocked. This meant the child got stuck trying to
disable all log channels.

The bug existed for a while but only started being apparent after
D37930, which started using ThreadLauncher (which uses logging) instead
of std::thread (which does not) for launching TaskPool threads.

The fix is to use pthread_atfork to make sure noone is writing a log
message while we are forking.

Reviewers: zturner, eugene, clayborg

Subscribers: lldb-commits

Differential Revision: https://reviews.llvm.org/D38938

llvm-svn: 316173
2017-10-19 17:40:51 +00:00
Zachary Turner 4479ac15c9 iwyu fixes on lldbUtility.
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
2017-04-06 18:12:24 +00:00
Pavel Labath 775588c0c3 Remove lldb streams from the Log class completely
Summary:
previously we switched to llvm streams for log output, this completes
the switch for the error streams.

I also clean up the includes and remove the unused argument from
DisableAllLogChannels().

This required adding a bit of boiler plate to convert the output in the
command interpreter, but that should go away when we switch command
results to use llvm streams as well.

Reviewers: zturner, eugene

Subscribers: lldb-commits, emaste

Differential Revision: https://reviews.llvm.org/D30894

llvm-svn: 297812
2017-03-15 09:06:58 +00:00
Pavel Labath f5aaa999b9 Fix remaining threading issues in Log.h
Summary:
This fixes two threading issues in the logging code. The access to the
mask and options flags had data races when we were trying to
enable/disable logging while another thread was writing to the log.
Since we can log from almost any context, and we want it to be fast, so
I avoided locking primitives and used atomic variables instead. I have
also removed the (unused) setters for the mask and flags to make sure
that the only way to set them is through the enable/disable channel
functions.

I also add tests, which when run under tsan, verify that the use cases
like "doing an LLDB_LOGV while another thread disables logging" are
data-race-free.

Reviewers: zturner, clayborg

Subscribers: lldb-commits

Differential Revision: https://reviews.llvm.org/D30702

llvm-svn: 297368
2017-03-09 10:16:07 +00:00
Pavel Labath a96eac62d6 Update log_options unit test
it was accessing the details of the Log class directly. Let it go
through the channel class instead.

This also discovered a bug when we were setting but not clearing the log
options when enabling a channel.

llvm-svn: 297053
2017-03-06 19:10:19 +00:00
Zachary Turner 6f9e690199 Move Log from Core -> Utility.
All references to Host and Core have been removed, so this
class can now safely be lowered into Utility.

Differential Revision: https://reviews.llvm.org/D30559

llvm-svn: 296909
2017-03-03 20:56:28 +00:00