[lldb][debugserver] Read/write SME registers on arm64 (#119171)

**Note:** The register reading and writing depends on new register
flavor support in thread_get_state/thread_set_state in the kernel,

[lldb][debugserver] Read/write SME registers on arm64 (#119171)

**Note:** The register reading and writing depends on new register
flavor support in thread_get_state/thread_set_state in the kernel, which
will be first available in macOS 15.4.

The Apple M4 line of cores includes the Scalable Matrix Extension (SME)
feature. The M4s do not implement Scalable Vector Extension (SVE),
although the processor is in Streaming SVE Mode when the SME is being
used. The most obvious side effects of being in SSVE Mode are that (on
the M4 cores) NEON instructions cannot be used, and watchpoints may get
false positives, the address comparisons are done at a lowered
granularity.

When SSVE mode is enabled, the kernel will provide the Streaming Vector
Length register, which is a maximum of 64 bytes with the M4. Also
provided are SVCR (with bits indicating if SSVE mode and SME mode are
enabled), TPIDR2, SVL. Then the SVE registers Z0..31 (SVL bytes long),
P0..15 (SVL/8 bytes), the ZA matrix register (SVL*SVL bytes), and the M4
supports SME2, so the ZT0 register (64 bytes).

When SSVE/SME are disabled, none of these registers are provided by the
kernel - reads and writes of them will fail.

Unlike Linux, lldb cannot modify the SVL through a thread_set_state
call, or change the processor state's SSVE/SME status. There is also no
way for a process to request a lowered SVL size today, so the work that
David did to handle VL/SVL changing while stepping through a process is
not an issue on Darwin today. But debugserver should be providing
everything necessary so we can reuse all of David's work on resizing the
register contexts in lldb if it happens in the future. debugbserver
sends svl, svcr, and tpidr2 in the expedited registers when a thread
stops, if SSVE|SME mode are enabled (if the kernel allows it to read the
ARM_SME_STATE register set).

While the maximum SVL is 64 bytes on M4, the AArch64 maximum possible
SVL is 256; this would give us a 64k ZA register. If debugserver sized
all of its register contexts assuming the largest possible SVL, we could
easily use 2MB more memory for the register contexts of all threads in a
process -- and on iOS et al, processes must run within a small memory
allotment and this would push us over that.

Much of the work in debugserver was changing the arm64 register context
from being a static compile-time array of register sets, to being
initialized at runtime if debugserver is running on a machine with SME.
The ZA is only created to the machine's actual maximum SVL. The size of
the 32 SVE Z registers is less significant so I am statically allocating
those to the architecturally largest possible SVL value today.

Also, debugserver includes information about registers that share the
same part of the register file. e.g. S0 and D0 are the lower parts of
the NEON 128-bit V0 register. And when running on an SME machine, v0 is
the lower 128 bits of the SVE Z0 register. So the register maps used
when defining the VFP registers must differ depending on the
capabilities of the cpu at runtime.

I also changed register reading in debugserver, where formerly when
debugserver was asked to read a register, and the thread_get_state read
of that register failed, it would return all zero's. This is necessary
when constructing a `g` packet that gets all registers - because there
is no separation between register bytes, the offsets are fixed. But when
we are asking for a single register (e.g. Z0) when not in SSVE/SME mode,
this should return an error.

This does mean that when you're running on an SME capabable machine, but
not in SME mode, and do `register read -a`, lldb will report that 48 SVE
registers were unavailable and 5 SME registers were unavailable. But
that's only when `-a` is used.

The register reading and writing depends on new register flavor support
in thread_get_state/thread_set_state in the kernel, which is not yet in
a release. The test case I wrote is skipped on current OSes. I pilfered
the SME register setup from some of David's existing SME test files;
there were a few Linux specific details in those tests that they weren't
easy to reuse on Darwin.

rdar://121608074

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[lldb][debugserver][NFC] Simplify macOS thread name fetching. (#111684)

Remove unnecessary `proc_pidinfo` calling.

[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++ equivale

[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

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[lldb/debugserver] Unify the breakpoint/watchpoint interface (NFCI)

Unify the interface for enabling and disabling breakpoints with their
watchpoint counterpart. This allows both to go through
DoHar

[lldb/debugserver] Unify the breakpoint/watchpoint interface (NFCI)

Unify the interface for enabling and disabling breakpoints with their
watchpoint counterpart. This allows both to go through
DoHardwareBreakpointAction.

Differential revision: https://reviews.llvm.org/D72981

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[lldb][NFC] Use static_cast instead of reinterpret_cast where possible

Summary: There are a few places in LLDB where we do a `reinterpret_cast` for conversions that we could also do with `static_cas

[lldb][NFC] Use static_cast instead of reinterpret_cast where possible

Summary: There are a few places in LLDB where we do a `reinterpret_cast` for conversions that we could also do with `static_cast`. This patch moves all this code to `static_cast`.

Reviewers: shafik, JDevlieghere, labath

Reviewed By: labath

Subscribers: arphaman, usaxena95, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D72161

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[debugserver] Fix IsUserReady thread filtering

Summary:
In 2010 (r118866), filtering code was added to debugserver to avoid reporting threads
that were "not ready to be displayed to the user". This

[debugserver] Fix IsUserReady thread filtering

Summary:
In 2010 (r118866), filtering code was added to debugserver to avoid reporting threads
that were "not ready to be displayed to the user". This code inspects the thread's
state and discards threads marked 'uninterruptible'. Turns out, this state is pretty
common and not only a characterisitic of 'user-readiness'. This filtering was tracked
down as the source of the flakiness of TestQueues and TestConcurrent* with the symptom
of missing threads.

We discussed with the kernel team and there should be no need for us to filter the
restult of task_threads(). Everything that is returned from there can be examined.
So I went on and tried to remove the filtering completely. This produces other test
failures, where we were reporting more theads than expected. Always threads that had
been terminated, but weren't removed from the task bookkeeping structures yet. Those
threads always had a PC of 0.

This patch changes the heuristic to make the filtering a little less strict and only
rejects threads that are 'uninteruptible' *and* have a PC of 0. This has proven to be
solid in my testing.

Reviewers: jasonmolenda, clayborg, jingham

Subscribers: jdoerfert, lldb-commits

Differential Revision: https://reviews.llvm.org/D58912

llvm-svn: 355555

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Replace 'ap' with 'up' suffix in variable names. (NFC)

The `ap` suffix is a remnant of lldb's former use of auto pointers,
before they got deprecated. Although all their uses were replaced by
unique

Replace 'ap' with 'up' suffix in variable names. (NFC)

The `ap` suffix is a remnant of lldb's former use of auto pointers,
before they got deprecated. Although all their uses were replaced by
unique pointers, some variables still carried the suffix.

In r353795 I removed another auto_ptr remnant, namely redundant calls to
::get for unique_pointers. Jim justly noted that this is a good
opportunity to clean up the variable names as well.

I went over all the changes to ensure my find-and-replace didn't have
any undesired side-effects. I hope I didn't miss any, but if you end up
at this commit doing a git blame on a weirdly named variable, please
know that the change was unintentional.

llvm-svn: 353912

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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 ne

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

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Simplify Boolean expressions

This patch simplifies boolean expressions acorss LLDB. It was generated
using clang-tidy with the following command:

run-clang-tidy.py -checks='-*,readability-simplify-

Simplify Boolean expressions

This patch simplifies boolean expressions acorss LLDB. It was generated
using clang-tidy with the following command:

run-clang-tidy.py -checks='-*,readability-simplify-boolean-expr' -format -fix $PWD

Differential revision: https://reviews.llvm.org/D55584

llvm-svn: 349215

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Change uses of strncpy in debugserver to strlcpy
for better safety.

<rdar://problem/32906923>

llvm-svn: 320242

fix format specifier warnings

llvm-svn: 297228

*** 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 t

*** 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

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Quiet build warnings on MacOSX.

llvm-svn: 245373

Fix warnings.

Reviewers: clayborg

Subscribers: lldb-commits

Differential Revision: http://reviews.llvm.org/D11404

llvm-svn: 242913

Fix debugserver warnings on MacOSX.

llvm-svn: 231692

Initial merge of some of the iOS 8 / Mac OS X Yosemite specific
lldb support. I'll be doing more testing & cleanup but I wanted to
get the initial checkin done.

This adds a new SBExpressionOptions:

Initial merge of some of the iOS 8 / Mac OS X Yosemite specific
lldb support. I'll be doing more testing & cleanup but I wanted to
get the initial checkin done.

This adds a new SBExpressionOptions::SetLanguage API for selecting a
language of an expression.

I added adds a new SBThread::GetInfoItemByPathString for retriving
information about a thread from that thread's StructuredData.

I added a new StructuredData class for representing
key-value/array/dictionary information (e.g. JSON formatted data).
Helper functions to read JSON and create a StructuredData object,
and to print a StructuredData object in JSON format are included.

A few Cocoa / Cocoa Touch data formatters were updated by Enrico
to track changes in iOS 8 / Yosemite.

Before we query a thread's extended information, the system runtime may
provide hints to the remote debug stub that it will use to retrieve values
out of runtime structures. I added a new SystemRuntime method
AddThreadExtendedInfoPacketHints which allows the SystemRuntime to add
key-value type data to the initial request that we send to the remote stub.

The thread-format formatter string can now retrieve values out of a thread's
extended info structured data. The default thread-format string picks up
two of these - thread.info.activity.name and thread.info.trace_messages.

I added a new "jThreadExtendedInfo" packet in debugserver; I will
add documentation to the lldb-gdb-remote.txt doc soon. It accepts
JSON formatted arguments (most importantly, "thread":threadnum) and
it returns a variety of information regarding the thread to lldb
in JSON format. This JSON return is scanned into a StructuredData
object that is associated with the thread; UI layers can query the
thread's StructuredData to see if key-values are present, and if
so, show them to the user. These key-values are likely to be
specific to different targets with some commonality among many
targets. For instance, many targets will be able to advertise the
pthread_t value for a thread.

I added an initial rough cut of "thread info" command which will print
the information about a thread from the jThreadExtendedInfo result.
I need to do more work to make this format reasonably.

Han Ming added calls into the pmenergy and pmsample libraries if
debugserver is run on Mac OS X Yosemite to get information about the
inferior's power use.

I added support to debugserver for gathering the Genealogy information
about threads, if it exists, and returning it in the jThreadExtendedInfo
JSON result.

llvm-svn: 210874

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<rdar://problem/15172417>

Added two new GDB server packets to debugserver: "QSaveRegisterState" and "QRestoreRegiterState".

"QSaveRegisterState" makes the remote GDB server save all register values

<rdar://problem/15172417>

Added two new GDB server packets to debugserver: "QSaveRegisterState" and "QRestoreRegiterState".

"QSaveRegisterState" makes the remote GDB server save all register values and it returns a save identifier as an unsigned integer. This packet can be used prior to running expressions to save all registers.

All registers can them we later restored with "QRestoreRegiterState:SAVEID" what SAVEID is the integer identifier that was returned from the call to QSaveRegisterState.

Cleaned up redundant code in lldb_private::Thread, lldb_private::ThreadPlanCallFunction.
Moved the lldb_private::Thread::RegisterCheckpoint into its own header file and it is now in the lldb_private namespace. Trimmed down the RegisterCheckpoint class to omit stuff that wasn't used (the stack ID).

Added a few new virtual methods to lldb_private::RegisterContext that allow subclasses to efficiently save/restore register states and changed the RegisterContextGDBRemote to take advantage of these new calls.

llvm-svn: 194621

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Get debugserver to call task_set_state to prime the control registers so that watchpoints
take for threads created while the program is running. Remove the testcase skips from TestConcurrentEvents.p

Get debugserver to call task_set_state to prime the control registers so that watchpoints
take for threads created while the program is running. Remove the testcase skips from TestConcurrentEvents.py,
since they all pass now, and fix TestWatchpointMultipleThreads.py - which should have caught this problem -
so it doesn't artificially break on new thread creation before the watchpoint triggers.

llvm.org/pr16566
<rdar://problem/14383244>

llvm-svn: 186132

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Remove some unnecessary uses of nub_break_t in the arm specific
support files for debugserver to fix a build failure for arm. Also
remove some of the code used for software-driven single instruction

Remove some unnecessary uses of nub_break_t in the arm specific
support files for debugserver to fix a build failure for arm. Also
remove some of the code used for software-driven single instruction
stepping; this is slowly being yanked out and these particular bits
overlap with the nub_break_t going away.

llvm-svn: 184828

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Huge performance improvements when one breakpoint contains many locations.

325,000 breakpoints for running "breakpoint set --func-regex ." on lldb itself (after hitting a breakpoint at main so that

Huge performance improvements when one breakpoint contains many locations.

325,000 breakpoints for running "breakpoint set --func-regex ." on lldb itself (after hitting a breakpoint at main so that LLDB.framework is loaded) used to take up to an hour to set, now we are down under a minute. With warm file caches, we are at 40 seconds, and that is with setting 325,000 breakpoint through the GDB remote API. Linux and the native debuggers might be faster. I haven't timed what how much is debug info parsing and how much is the protocol traffic to/from GDB remote.

That there were many performance issues. Most of them were due to storing breakpoints in the wrong data structures, or using the wrong iterators to traverse the lists, traversing the lists in inefficient ways, and not optimizing certain function name lookups/symbol merges correctly.

Debugging after that is also now very efficient. There were issues with replacing the breakpoint opcodes in memory that was read, and those routines were also fixed.

llvm-svn: 183820

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Change debugserver from using the mach port number (in debugserver's
own port namepsace) as the thread identifier to using the system-wide
globally unique thread id as the thread identifier number.

Change debugserver from using the mach port number (in debugserver's
own port namepsace) as the thread identifier to using the system-wide
globally unique thread id as the thread identifier number.

MachThread.cpp keeps both the unique id and the mach port number
for each thread. All layers outside MachThread class use the unique
id with three exceptions: (1) Mach exceptions come in with the port
number (thread_port) which needs to be translated, (2) any calls to
low-level thread_get_state/thread_set_state/thread_suspend etc need
to use the mach port number, (3) MachThreadList::UpdateThreadList
which creates the MachThread objects gets the unique id and passes
it to the MachThread ctor as an argument.

In general, any time nub_thread_t is used, it is now referring to a
unique thread id. Any time a thread_t is used, it is now referring
to a mach port number. There was some interchangability of these
types previously. nub_thread_t has also been changed to a 64-bit
type which necessitated some printf specification string changes.

I haven't been able to test these changes extensively yet but want
to checkpoint the work. The scenarios I've been testing are all
working correctly so while there may be some corner cases I haven't
hit yet, I think it is substantially correct.

<rdar://problem/12931414>

llvm-svn: 175870

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rdar://problem/11320188

Designate MachThreadList as a transaction coordinator when doing Enable/DisableHardwareWatchpoint on the list of threads.
In case the operation (iterating on the threads and

rdar://problem/11320188

Designate MachThreadList as a transaction coordinator when doing Enable/DisableHardwareWatchpoint on the list of threads.
In case the operation (iterating on the threads and doing enable/disable) fails in the middle, we rollback the already
enabled/disabled threads to their checkpointed states. When all the threads succeed in enable/disable, we ask each thread
to finsih the transaction and commit the change of the debug state.

llvm-svn: 157858

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Add the capability to display the number of supported hardware watchpoints to the "watchpoint list" command.

Add default Process::GetWatchpointSupportInfo() impl which returns an error of "not suppo

Add the capability to display the number of supported hardware watchpoints to the "watchpoint list" command.

Add default Process::GetWatchpointSupportInfo() impl which returns an error of "not supported".
Add "qWatchpointSupportInfo" packet to the gdb communication layer to support this, and modify TestWatchpointCommands.py to test it.

llvm-svn: 157345

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Check the return value of GetBasicInfo before dereferencing it. <rdar://problem/10568492>

llvm-svn: 147883

Enabled the "printf" attribute on all debugserver logging functions and fixed
the ensuing mayhem.

llvm-svn: 143244