Commit Graph

1415 Commits

Author SHA1 Message Date
Jonas Devlieghere
aed965d55d [lldb] Don't construct the demangled strings while indexing the symbol table
The symbol table needs to demangle all symbol names when building its
index. However, this doesn't require the full mangled name: we only need
the base name and the function declaration context. Currently, we always
construct the demangled string during indexing and cache it in the
string pool as a way to speed up future lookups.

Constructing the demangled string is by far the most expensive step of
the demangling process, because the output string can be exponentially
larger than the input and unless you're dumping the symbol table, many
of those demangled names will not be needed again.

This patch avoids constructing the full demangled string when we can
partially demangle. This speeds up indexing and reduces memory usage.

I gathered some numbers by attaching to Slack:

Before
------

  Memory usage: 280MB
  Benchmark 1: ./bin/lldb -n Slack -o quit
    Time (mean ± σ):      4.829 s ±  0.518 s    [User: 4.012 s, System: 0.208 s]
    Range (min … max):    4.624 s …  6.294 s    10 runs

After
-----

  Memory usage: 189MB
  Benchmark 1: ./bin/lldb -n Slack -o quit
    Time (mean ± σ):      4.182 s ±  0.025 s    [User: 3.536 s, System: 0.192 s]
    Range (min … max):    4.152 s …  4.233 s    10 runs

Differential revision: https://reviews.llvm.org/D118814
2022-02-04 10:17:39 -08:00
Zequan Wu
607ffa5515 [LLDB] Fix window bot failure
This attempts to fix this bot failure: https://lab.llvm.org/buildbot/#/builders/83/builds/14736 caused by D118750 by un-xfail those expected failed tests.

Differential Revision: https://reviews.llvm.org/D118866
2022-02-03 11:27:48 -08:00
Michał Górny
ac666d1799 [lldb] [gdb-remote] Support getting siginfo via API
Add Thread::GetSiginfo() and SBThread::GetSiginfo() methods to retrieve
the siginfo value from server.

Differential Revision: https://reviews.llvm.org/D118055
2022-01-28 17:47:47 +01:00
Michał Górny
59a3f65f5e Revert "[lldb] [gdb-remote] Support getting siginfo via API"
This reverts commit 1a8f60f5f5.
The API requires further work.
2022-01-28 10:15:52 +01:00
Shubham Sandeep Rastogi
cf93a08575 Fixed typos in TestLldbGdbServer.py
Fixed more typos
2022-01-27 14:12:24 -08:00
Shubham Sandeep Rastogi
867fdec194 Disable TestLldbGdbServer on Dwarf2 and clang versions below 14
We have been noticing issues with the lldb bots on builds using versions below clang 14 and dwarf 2, so to make sure we can get clean builds for a while, we are disabling the tests for those versions

Differential Revision: https://reviews.llvm.org/D118395
2022-01-27 14:02:35 -08:00
Shubham Sandeep Rastogi
ee54868a76 Revert "Disable TestLldbGdbServer on Dwarf2 and clang versions below 14"
This reverts commit cd31763770.
2022-01-27 13:36:21 -08:00
Shubham Sandeep Rastogi
cd31763770 Disable TestLldbGdbServer on Dwarf2 and clang versions below 14
We have been noticing issues with the lldb bots on builds using versions below clang 14 and dwarf 2, so to make sure we can get clean builds for a while, we are disabling the tests for those versions

Differential Revision: https://reviews.llvm.org/D118395
2022-01-27 13:29:34 -08:00
Med Ismail Bennani
48c36a15a3 [lldb/test] Disable test_launch_scripted_process_stack_frames on x86_64
There seems to be an issue on x86_64 when launching a ScriptdProcess.
This disables temporarely the test that causes the bot to timeout until
I finish investigating the issue.

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2022-01-27 18:42:08 +01:00
Pavel Labath
33eb3f14eb [lldb] Delete TestBacktraceAll.py
This test is completely nondeterministic, environment-dependent and does
not test what it was supposed to test (reverting the associated patch
does not make it fail).

I tried to figure out what the patch was meant to fix to see if I can
create a better test with the current tools, but I was not able to
understand the problem (it sounds like it has something to do with local
classes, but I don't understand the details).
2022-01-27 15:01:08 +01:00
Michał Górny
1a8f60f5f5 [lldb] [gdb-remote] Support getting siginfo via API
Add Thread::GetSiginfo() and SBThread::GetSiginfo() methods to retrieve
the siginfo value from server.

Differential Revision: https://reviews.llvm.org/D118055
2022-01-27 13:33:47 +01:00
Med Ismail Bennani
aae3c4f2b4 [lldb/test] Skip TestSBModule unless darwin
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2022-01-27 01:05:12 +01:00
Med Ismail Bennani
a6b5624372 Revert "[lldb/test] Try to fix TestSBModule failure"
This reverts commit 326516448c.
2022-01-27 01:04:38 +01:00
Med Ismail Bennani
326516448c [lldb/test] Try to fix TestSBModule failure
This should fix https://lab.llvm.org/buildbot/#/builders/68/builds/25571

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2022-01-27 01:00:29 +01:00
Med Ismail Bennani
ff52ef334b [lldb/API] Add ability to check if module is backed by a file on disk
This patch introduces a new SBAPI method: `SBModule::IsFileBacked`

As the name suggests, it tells the user if the module's object file is
on disk or in memory.

rdar://68538278

Differential Revision: https://reviews.llvm.org/D118261

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2022-01-26 20:40:24 +01:00
David Spickett
070090d08e [lldb] Add option to show memory tags in memory read output
This adds an option --show-tags to "memory read".

(lldb) memory read mte_buf mte_buf+32 -f "x" -s8 --show-tags
0x900fffff7ff8000: 0x0000000000000000 0x0000000000000000 (tag: 0x0)
0x900fffff7ff8010: 0x0000000000000000 0x0000000000000000 (tag: 0x1)

Tags are printed on the end of each line, if that
line has any tags associated with it. Meaning that
untagged memory output is unchanged.

Tags are printed based on the granule(s) of memory that
a line covers. So you may have lines with 1 tag, with many
tags, no tags or partially tagged lines.

In the case of partially tagged lines, untagged granules
will show "<no tag>" so that the ordering is obvious.
For example, a line that covers 2 granules where the first
is not tagged:

(lldb) memory read mte_buf-16 mte_buf+16 -l32 -f"x" --show-tags
0x900fffff7ff7ff0: 0x00000000 <...> (tags: <no tag> 0x0)

Untagged lines will just not have the "(tags: ..." at all.
Though they may be part of a larger output that does have
some tagged lines.

To do this I've extended DumpDataExtractor to also print
memory tags where it has a valid execution context and
is asked to print them.

There are no special alignment requirements, simply
use "memory read" as usual. All alignment is handled
in DumpDataExtractor.

We use MakeTaggedRanges to find all the tagged memory
in the current dump, then read all that into a MemoryTagMap.

The tag map is populated once in DumpDataExtractor and re-used
for each subsequently printed line (or recursive call of
DumpDataExtractor, which some formats do).

Reviewed By: omjavaid

Differential Revision: https://reviews.llvm.org/D107140
2022-01-26 14:40:39 +00:00
Jonas Devlieghere
cd8122b27f [lldb] Add ConstString memory usage statistics
Add statistics about the memory usage of the string pool. I'm
particularly interested in the memory used by the allocator, i.e. the
number of bytes actually used by the allocator it self as well as the
number of bytes allocated through the allocator.

Differential revision: https://reviews.llvm.org/D117914
2022-01-24 15:13:17 -08:00
Med Ismail Bennani
c3ca2c6b14 [lldb/test] Fix TestScriptedProcess.test_scripted_process_and_scripted_thread
This patch updates `dummy_scripted_process.py` to report the dummy
thread correctly to reflect the changes introduced by `d3e0f7e`.

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2022-01-24 21:48:31 +01:00
Med Ismail Bennani
cfa55bfe78 [lldb/Plugins] Enrich ScriptedThreads Stop Reasons with Exceptions
This patch adds Exceptions to the list of supported stop reasons for
Scripted Threads.

The main motivation for this is that breakpoints are triggered as a
special exception class on ARM platforms, so adding it as a stop reason
allows the ScriptedProcess to selected the ScriptedThread that stopped at
a breakpoint (or crashed :p).

rdar://87430376

Differential Revision: https://reviews.llvm.org/D117074

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2022-01-24 20:25:54 +01:00
Med Ismail Bennani
d3e0f7e150 [lldb/Plugins] Add support of multiple ScriptedThreads in a ScriptedProcess
This patch adds support of multiple Scripted Threads in a ScriptedProcess.

This is done by fetching the Scripted Threads info dictionary at every
ScriptedProcess::DoUpdateThreadList and iterate over each element to
create a new ScriptedThread using the object instance, if it was not
already available.

This patch also adds the ability to pass a pointer of a script interpreter
object instance to initialize a ScriptedInterface instead of having to call
the script object initializer in the ScriptedInterface constructor.

This is used to instantiate the ScriptedThreadInterface from the
ScriptedThread constructor, to be able to perform call on that script
interpreter object instance.

Finally, the patch also updates the scripted process test to check for
multiple threads.

rdar://84507704

Differential Revision: https://reviews.llvm.org/D117071

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2022-01-24 20:25:53 +01:00
David Spickett
7d19566c3b [lldb] Ignore non-address bits in "memory find" arguments
This removes the non-address bits before we try to use
the addresses.

Meaning that when results are shown, those results won't
show non-address bits either. This follows what "memory read"
has done. On the grounds that non-address bits are a property
of a pointer, not the memory pointed to.

I've added testing and merged the find and read tests into one
file.

Note that there are no API side changes because "memory find"
does not have an equivalent API call.

Reviewed By: omjavaid

Differential Revision: https://reviews.llvm.org/D117299
2022-01-24 10:42:49 +00:00
David Blaikie
8b280df504 Rough guess at fixing lldb tests to handle Clang defaulting to DWARFv5 2022-01-23 21:24:25 -08:00
Dave Lee
b95150418f [lldb] Allow aliases to aliases of raw input commands
Allow users to create aliases for aliases to raw input commands. That probably
sounds convoluted, so here's an example:

```
command alias some-setup env SOMEVAR=SOMEVALUE
```

This an alias based on `env`, which itself is an alias for `_regex-env`.
`_regex-env` is a `command regex` command, which takes raw input.

The above `some-setup` alias fails with:

```
error: Unable to create requested alias.
```

This change allows such aliases to be created. lldb already supports aliases to
aliases for parsed commands.

Differential Revision: https://reviews.llvm.org/D117259
2022-01-21 17:57:34 -08:00
David Spickett
787f91b0bb [lldb] Remove non-address bits from addresses given to memory tag commands
Although the memory tag commands use a memory tag manager to handle
addresses, that only removes the top byte.

That top byte is 4 bits of memory tag and 4 free bits, which is more
than it should strictly remove but that's how it is for now.

There are other non-address bit uses like pointer authentication.
To ensure the memory tag manager only has to deal with memory tags,
use the ABI plugin to remove the rest.

The tag access test has been updated to sign all the relevant pointers
and require that we're running on a system with pointer authentication
in addition to memory tagging.

The pointers will look like:
<4 bit user tag><4 bit memory tag><signature><bit virtual address>

Note that there is currently no API for reading memory tags. It will
also have to consider this when it arrives.

Reviewed By: omjavaid

Differential Revision: https://reviews.llvm.org/D117672
2022-01-20 10:48:14 +00:00
Pavel Labath
903424532f [lldb] Introduce SBPlatform::SetSDKRoot
It complements the existing SBDebugger::SetCurrentPlatformSDKRoot and
allows one to set the sysroot of a platform without making it current.

Differential Revision: https://reviews.llvm.org/D117550
2022-01-19 12:49:47 +01:00
Michał Górny
e69a3d18f4 [lldb] [gdb-remote] Support client fallback for servers without reg defs
Provide minimal register definition defaults for working with servers
that implement neither target.xml nor qRegisterInfo packets.  This is
useful e.g. when interacting with FreeBSD's kernel minimal gdbserver
that does not send target.xml but uses the same layout for its supported
register subset as GDB.

The prerequisite for this is the ability to determine the correct
architecture, e.g. from the target executable.

Differential Revision: https://reviews.llvm.org/D116896
2022-01-17 22:31:49 +01:00
Jonas Devlieghere
a6469cdbc4 [lldb] Correctly display the number of types found
Correctly display the number of types found for `target modules lookup
--type` and add a test.

Fixes #53219
2022-01-15 10:31:49 -08:00
Dave Lee
a7e7f541c0 [lldb] Remove anon struct from frame-var-anon-unions test
This test for anonymous unions seems off. It tests the following:

```
union {
  // fields
};

struct {
  // fields
} var{...};
```

Both are anonymous types, but the first does not declare a variable and the
second one does. The test then checks that `frame var` can directly access the
fields of the anonymous union, but can't directly access the fields of the
anonymous struct variable.

The second test, to directly access the members of the struct variable, seems
pointless as similar code would not compile. A demonstration:

```
struct {
  int a;
  int z;
} a_z{23, 45};

printf("%d\n", a_z.a); // fine
printf("%d\n", a); // this does not compile
```

Since we can't directly access the fields in code, I'm not sure there's a
reason to test that lldb also can't directly access them (other than perhaps as
a regression test).

Differential Revision: https://reviews.llvm.org/D116863
2022-01-15 10:20:52 -08:00
Jonas Devlieghere
a10692c734 [lldb] Only promote -Wignored-attributes to an error
Avoid other warnings from failing the test, such as
-Wunused-command-line-argument in the downstream Swift fork.
2022-01-14 16:19:16 -08:00
Muhammad Omair Javaid
df13239c11 [LLDB] Skip TestIOHandlerPythonREPLSigint.py on AArch64/Linux
TestIOHandlerPythonREPLSigint.py is running falky on AArch64/Linux
buildbot failing randomly. Skipping it for AArch64/Linux as well.
2022-01-15 03:24:26 +05:00
Muhammad Omair Javaid
3dc858f984 [LLDB] Skip TestIOHandlerPythonREPLSigint.py on Arm/Linux
TestIOHandlerPythonREPLSigint.py is failing on Arm/Linux buildbot. I am
marking it as skip for now.
2022-01-14 15:46:54 +05:00
Jonas Devlieghere
049ae93097 [lldb] Fix that the embedded Python REPL crashes if it receives SIGINT
When LLDB receives a SIGINT while running the embedded Python REPL it
currently just crashes in ScriptInterpreterPythonImpl::Interrupt with an
error such as the one below:

  Fatal Python error: PyThreadState_Get: the function must be called
  with the GIL held, but the GIL is released (the current Python thread
  state is NULL)

The faulty code that causes this error is this part of
ScriptInterpreterPythonImpl::Interrupt:

  PyThreadState *state = PyThreadState_GET();
  if (!state)
    state = GetThreadState();
  if (state) {
    long tid = state->thread_id;
    PyThreadState_Swap(state);
    int num_threads = PyThreadState_SetAsyncExc(tid, PyExc_KeyboardInterrupt);

The obvious fix I tried is to just acquire the GIL before this code is
running which fixes the crash but the KeyboardInterrupt we want to raise
immediately is actually just queued and would only be raised once the
next line of input has been parsed (which e.g. won't interrupt Python
code that is currently waiting on a timer or IO from what I can see).
Also none of the functions we call here is marked as safe to be called
from a signal handler from what I can see, so we might still end up
crashing here with some bad timing.

Python 3.2 introduced PyErr_SetInterrupt to solve this and the function
takes care of all the details and avoids doing anything that isn't safe
to do inside a signal handler. The only thing we need to do is to
manually setup our own fake SIGINT handler that behaves the same way as
the standalone Python REPL signal handler (which raises a
KeyboardInterrupt).

From what I understand the old code used to work with Python 2 so I kept
the old code around until we officially drop support for Python 2.

There is a small gap here with Python 3.0->3.1 where we might still be
crashing, but those versions have reached their EOL more than a decade
ago so I think we don't need to bother about them.

Differential revision: https://reviews.llvm.org/D104886
2022-01-13 15:27:38 -08:00
David Spickett
cf7bfd6d05 [lldb][AArch64] Remove armv8.3-a flag from tagged memory read test
This was left over from when I had used some pointer authentication
instructions to sign the pointer. Then I realised that simply setting
the top byte is enough to prove the ABI plugin is being called.

Top byte ignore is a feature of the armv8-a architecure and doesn't
need any extra compiler flags.
2022-01-13 14:25:18 +00:00
Michał Górny
1e74e5e9e3 [lldb] [llgs] Implement qXfer:siginfo:read
Implement the qXfer:siginfo:read that is used to read the siginfo_t
(extended signal information) for the current thread.  This is currently
implemented on FreeBSD and Linux.

Differential Revision: https://reviews.llvm.org/D117113
2022-01-13 11:24:36 +01:00
Stella Stamenova
8fec756c0b [lldb] Disable one more watchpoint test on Windows
This should be the last remaining flaky watchpoint test on Windows
2022-01-12 08:55:48 -08:00
David Spickett
3fd9c90bdc [lldb][AArch64] Correct top nibble setting in memory tag read tests
Due to a missing cast the << 60 always resulted in zero leaving
the top nibble empty. So we weren't actually testing that lldb
ignores those bits in addition to the tag bits.

Correct that and also set the top nibbles to ascending values
so that we can catch if lldb only removes one of the tag bits
and top nibble, but not both.

In future the tag manager will likely only remove the tag bits
and leave non-address bits to the ABI plugin but for now make
sure we're testing what we claim to implement.
2022-01-12 12:28:13 +00:00
David Spickett
091e760cd3 [lldb] Don't print "Command Options Usage:" for an alias with no options
"shell" is an alias to "platform shell -h --". Previously you would get this
help text:

(lldb) help shell
Run a shell command on the host.  Expects 'raw' input (see 'help raw-input'.)

Syntax: shell <shell-command>

Command Options Usage:

'shell' is an abbreviation for 'platform shell -h   --'

Since the code doesn't handle the base command having options
but the alias removing them. With these changes you get:

(lldb) help shell
Run a shell command on the host.  Expects 'raw' input (see 'help raw-input'.)

Syntax: shell <shell-command>

'shell' is an abbreviation for 'platform shell -h   --'

Note that we already handle a non-alias command having no options,
for example "quit":

(lldb) help quit
Quit the LLDB debugger.

Syntax: quit [exit-code]

Reviewed By: JDevlieghere, jingham

Differential Revision: https://reviews.llvm.org/D117004
2022-01-12 10:07:38 +00:00
Dave Lee
06c7bdc8f1 [lldb] Specify LLVM target requirements in TestLaunchProcessPosixSpawn 2022-01-11 19:00:47 -08:00
David Spickett
88fdce5be6 [lldb] Remove non address bits from memory read arguments
Addresses on AArch64 can have top byte tags, memory tags and pointer
authentication signatures in the upper bits.

While testing memory tagging I found that memory read couldn't
read a range if the two addresses had different tags. The same
could apply to signed pointers given the right circumstance.

(lldb) memory read mte_buf_alt_tag mte_buf+16
error: end address (0x900fffff7ff8010) must be greater than the start
address (0xa00fffff7ff8000).

Or it would try to read a lot more memory than expected.

(lldb) memory read mte_buf mte_buf_alt_tag+16
error: Normally, 'memory read' will not read over 1024 bytes of data.
error: Please use --force to override this restriction just once.
error: or set target.max-memory-read-size if you will often need a
larger limit.

Fix this by removing non address bits before we calculate the read
range. A test is added for AArch64 Linux that confirms this by using
the top byte ignore feature.

This means that if you do read with a tagged pointer the output
does not include those tags. This is potentially confusing but I think
overall it's better that we don't pretend that we're reading memory
from a range that the process is unable to map.

(lldb) p ptr1
(char *) $4 = 0x3400fffffffff140 "\x80\xf1\xff\xff\xff\xff"
(lldb) p ptr2
(char *) $5 = 0x5600fffffffff140 "\x80\xf1\xff\xff\xff\xff"
(lldb) memory read ptr1 ptr2+16
0xfffffffff140: 80 f1 ff ff ff ff 00 00 38 70 bc f7 ff ff 00 00  ........8p......

Reviewed By: omjavaid, danielkiss

Differential Revision: https://reviews.llvm.org/D103626
2022-01-11 13:24:09 +00:00
Stella Stamenova
9b5cf7267b [lldb] Disable several lldb tests that are flaky on Windows
This tests have recently become flaky (flakier?) causing occasional failures in the windows lldb buildbot
2022-01-10 10:21:12 -08:00
Pavel Labath
8ccfcab34f [lldb/platform-gdb] Clear cached protocol state upon disconnection
Previously we would persist the flags indicating whether the remote side
supports a particular feature across reconnects, which is obviously not
a good idea.

I implement the clearing by nuking (its the only way to be sure :) the
entire GDBRemoteCommunication object in the disconnect operation and
creating a new one upon connection. This allows us to maintain a nice
invariant that the GDBRemoteCommunication object (which is now a
pointer) exists only if it is connected. The downside to that is that a
lot of functions now needs to check the validity of the pointer instead
of blindly accessing the object.

The process communication does not suffer from the same issue because we
always destroy the entire Process object for a relaunch.

Differential Revision: https://reviews.llvm.org/D116539
2022-01-10 16:27:30 +01:00
Dave Lee
c4cdf86569 [lldb] Skip TestTargetXMLArch if no support for x86 target
If LLVM is configured without X86 as one of its TARGETS_TO_BUILD, then lldb
will crash when using X86 disassembler (which it does while running `image
show-unwind`).
2022-01-09 22:40:03 -08:00
Dave Lee
ed3a4a4948 [lldb] Skip TestVSCode_coreFile if no x86 target support 2022-01-09 22:01:31 -08:00
Dave Lee
4a8549354c [lldb] Guard libstdc++ specific 'frame var' test
While working on D116788 (properly error out of `frame var`), this libstdc++
specific `frame var` invocation was found in the tests. This test is in the
generic directory, but has this one case that requires libstdc++. The fix here
is to put the one `expect()` inside of a condition that checks for libstdc++.

Differential Revision: https://reviews.llvm.org/D116901
2022-01-09 21:37:42 -08:00
Dave Lee
aad27a8907 [lldb] Check for arm64 in TestDisassembleRawData
This test checks for `aarch64` but the lit config could also contain `arm64`.
This change adds `arm64` to make the test pass in all cases.

Differential Revision: https://reviews.llvm.org/D116912
2022-01-09 21:36:55 -08:00
Dave Lee
08f70adedb Revert "[lldb] Set result error state in 'frame variable'"
This reverts commit 2bcff220bf.
2022-01-09 14:12:47 -08:00
Dave Lee
2bcff220bf [lldb] Set result error state in 'frame variable'
Ensure that errors in `frame variable` are reflected in result object.

The statistics for `frame variable` show invocations as being successful, even
when executing one of the error paths.

This change replaces `result.GetErrorStream()` with `result.AppendError()`,
which also sets the status to `eReturnStatusFailed`.

Differential Revision: https://reviews.llvm.org/D116788

(cherry picked from commit 2c7d10c412)
2022-01-09 13:26:30 -08:00
Dave Lee
39ea676d9d [lldb] Compute fully qualified command names in FindCommandsForApropos
Fixes incomplete command names in `apropos` results.

The full command names given by `apropos` have come from command name string
literals given to `CommandObject` constructors. For most commands, this has
been accurate, but some commands have incorrect strings. This results in
`apropos` output that doesn't tell the user the full command name they might
want learn more about. These strings can be fixed.

There's a seperate issue that can't be fixed as easily: plugin commands. With
the way they're implemented, plugin commands have to exclude the root command
from their command name string. To illustrate, the `language objc` subcommand
has to set its command name string to "objc", which results in apropos printing
results as `objc ...` instead of `language objc ...`.

To fix both of these issues, this commit changes `FindCommandsForApropos` to
derive the fully qualified command name using the keys of subcommand maps.

Differential Revision: https://reviews.llvm.org/D116491

(cherry picked from commit b3bfd595a5)
2022-01-09 12:11:32 -08:00
Jonas Devlieghere
ab7618914d [lldb] Use lit_config.note to print module cache message 2022-01-07 13:35:18 -08:00
Ben Jackson
7244e9c2f5 [LLDB] libcxx summary formatters for std::string_view
When printing a std::string_view, print the referenced string as the
summary. Support string_view, u32string_view, u16string_view and
wstring_view, as we do for std::string and friends.

This is based on the existing fomratter for std::string, and just
extracts the data and length members, pushing them through the existing
string formatter.

In testing this, a "FIXME" was corrected for printing of non-ASCII empty
values. Previously, the "u", 'U" etc. prefixes were not printed for
basic_string<> types that were not char. This is trivial to resolve by
printing the prefix before the "".

Differential revision: https://reviews.llvm.org/D112222
2022-01-07 11:41:16 -08:00