Commit Graph

13818 Commits

Author SHA1 Message Date
David Spickett c65627a1fe Revert "[lldb] Don't send invalid region addresses to lldb server"
This reverts commit c687af0c30
due to a test failure on Windows.
2020-09-17 13:07:44 +01:00
David Spickett c687af0c30 [lldb] Don't send invalid region addresses to lldb server
Previously when <addr> in "memory region <addr>" didn't
parse correctly, we'd print an error then also ask lldb-server
for a region containing LLDB_INVALID_ADDRESS.

(lldb) memory region not_an_address
error: invalid address argument "not_an_address"...
error: Server returned invalid range

Only send the command to lldb-server if the address
parsed correctly.

(lldb) memory region not_an_address
error: invalid address argument "not_an_address"...

Reviewed By: labath

Differential Revision: https://reviews.llvm.org/D87694
2020-09-17 10:26:16 +01:00
Jonas Devlieghere 57dd92746a [lldb] Return FileSP and StreamFileSP by value in IOHandler (NFC)
Smart pointers should be returned by value.
2020-09-16 21:15:05 -07:00
Eric Christopher c140322819 Use zu rather than llu format specifier for size_t (-Wformat warning fix). 2020-09-16 19:28:05 -07:00
Patrick Beard f723d193e2 Add '<' meta command to read in code from external file
Perform all error handling in ReadCode()

Add :help text describing “< path”, add extra line before Commands

Differential Revision: https://reviews.llvm.org/D87640
2020-09-16 11:36:54 -07:00
Greg Clayton 79f22b1f99 Fix .debug_aranges parsing.
Code was added that used llvm error checking to parse .debug_aranges, but the error check after parsing the DWARFDebugArangesSet was reversed and was causing no error to be returned with no valid address ranges being actually used. This meant we always would fall back onto creating out own address ranges by parsing the compile unit's ranges. This was causing problems for cases where the DW_TAG_compile_unit had a single address range by using a DW_AT_low_pc and DW_AT_high_pc attribute pair (not using a DW_AT_ranges attribute), but the .debug_aranges had correct split ranges. In this case we would end up using the single range for the compile unit that encompassed all of the ranges from the .debug_aranges section and would cause address resolving issues in LLDB where address lookups would fail for certain addresses.

Differential Revision: https://reviews.llvm.org/D87626
2020-09-15 11:50:57 -07:00
Jonas Devlieghere 127faae752 [lldb] Add -l/--language option to script command
Make it possible to run the script command with a different language
than currently selected.

  $ ./bin/lldb -l python
  (lldb) script -l lua
  >>> io.stdout:write("Hello, World!\n")
  Hello, World!

When passing the language option and a raw command, you need to separate
the flag from the script code with --.

  $ ./bin/lldb -l python
  (lldb) script -l lua -- io.stdout:write("Hello, World!\n")
  Hello, World!

Differential revision: https://reviews.llvm.org/D86996
2020-09-15 09:40:17 -07:00
Pavel Labath af3789a188 [lldb] Improve qemu interop for aarch64
qemu calls the "fp" and "lr" registers via their generic names
(x29/x30). This mismatch manifested itself as not being able to unwind
or display values of some local variables.
2020-09-15 13:32:08 +02:00
Mateusz Mikuła cc76965b19 [MinGW] Use lib prefix for libraries
In MinGW world, UNIX like lib prefix is preferred for the libraries.
This patch adjusts CMake files to do that.

Differential Revision: https://reviews.llvm.org/D87517
2020-09-12 22:01:29 +03:00
Jonas Devlieghere 33eb647042 [lldb] Use GetNonKVOClassDescriptor to get the NSDictionary class descriptor
On macOS Big Sur the class descriptor contains the NSKVONotifying_
prefix. This is covered by TestDataFormatterObjCKVO.

Differential revision: https://reviews.llvm.org/D87545
2020-09-11 17:37:14 -07:00
Med Ismail Bennani 4da8fa45a0 [lldb/API] Add Breakpoint::SerializeToStructuredData to SBAPI
This patch adds a way to fetch breakpoint metadatas as a serialized
`Structured` Data format (JSON). This can be used by IDEs to update
their UI when a breakpoint is set or modified from the console.

rdar://11013798

Differential Revision: https://reviews.llvm.org/D87491

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2020-09-11 20:09:55 +02:00
Jonas Devlieghere bc0a35f3b7 [lldb] Add missing LLDB_REGISTER_CONSTRUCTOR in SBPlatform
This fixes the following assertion in TestPlatformPython.py.

  Assertion failed: (id != 0 && "Forgot to add function to
  registry?")
2020-09-10 18:50:02 -07:00
Kamil Rytarowski 52f42720b2 [lldb] [netbsd] Avoid comparison of signed and unsigned integers
Cast ProcessID to ::pid_t.
2020-09-10 15:49:15 +02:00
Raphael Isemann b85222520f [lldb] Enable std::pair in CxxModuleHandler
This adds support for substituting std::pair instantiations with enabled
import-std-module.

With the fixes in parent revisions we can currently substitute a single pair
(however, a result that returns a second pair currently causes LLDB to crash
while importing the second template instantiation).

Reviewed By: aprantl

Differential Revision: https://reviews.llvm.org/D85141
2020-09-09 10:49:53 +02:00
Raphael Isemann 7866b91405 [lldb] Fix a crash when the ASTImporter is giving us two Imported callbacks for the same target decl
The ASTImporter has an `Imported(From, To)` callback that notifies subclasses
that a declaration has been imported in some way. LLDB uses this in the
`CompleteTagDeclsScope` to see which records have been imported into the scratch
context. If the record was declared inside the expression, then the
`CompleteTagDeclsScope` will forcibly import the full definition of that record
to the scratch context so that the expression AST can safely be disposed later
(otherwise we might end up going back to the deleted AST to complete the
minimally imported record). The way this is implemented is that there is a list
of decls that need to be imported (`m_decls_to_complete`) and we keep completing
the declarations inside that list until the list is empty. Every `To` Decl we
get via the `Imported` callback will be added to the list of Decls to be
completed.

There are some situations where the ASTImporter will actually give us two
`Imported` calls with the same `To` Decl. One way where this happens is if the
ASTImporter decides to merge an imported definition into an already imported
one. Another way is that the ASTImporter just happens to get two calls to
`ASTImporter::Import` for the same Decl. This for example happens when importing
the DeclContext of a Decl requires importing the Decl itself, such as when
importing a RecordDecl that was declared inside a function.

The bug addressed in this patch is that when we end up getting two `Imported`
calls for the same `To` Decl, then we would crash in the
`CompleteTagDeclsScope`.  That's because the first time we complete the Decl we
remove the Origin tracking information (that maps the Decl back to from where it
came from). The next time we try to complete the same `To` Decl the Origin
tracking information is gone and we hit the `to_context_md->getOrigin(decl).ctx
== m_src_ctx` assert (`getOrigin(decl).ctx` is a nullptr the second time as the
Origin was deleted).

This is actually a regression coming from D72495. Before D72495
`m_decls_to_complete` was actually a set so every declaration in there could
only be queued once to be completed. The set was changed to a vector to make the
iteration over it deterministic, but that also causes that we now potentially
end up trying to complete a Decl twice.

This patch essentially just reverts D72495 and makes the `CompleteTagDeclsScope`
use a SetVector for the list of declarations to be completed. The SetVector
should filter out the duplicates (as the original `set` did) and also ensure that
the completion order is deterministic. I actually couldn't find any way to cause
LLDB to reproduce this bug by merging declarations (this would require that we
for example declare two namespaces in a non-top-level expression which isn't
possible). But the bug reproduces very easily by just declaring a class in an
expression, so that's what the test is doing.

Reviewed By: shafik

Differential Revision: https://reviews.llvm.org/D85648
2020-09-09 10:31:39 +02:00
Raphael Isemann 32c8da41dc [lldb] Don't infinite loop in SemaSourceWithPriorities::CompleteType when trying to complete a forward decl
SemaSourceWithPriorities is a special SemaSource that wraps our normal LLDB
ExternalASTSource and the ASTReader (which is used for the C++ module loading).
It's only active when the `import-std-module` setting is turned on.

The `CompleteType` function there in `SemaSourceWithPriorities` is looping over
all ExternalASTSources and asks each to complete the type. However, that loop is
in another loop that keeps doing that until the type is complete. If that
function is ever called on a type that is a forward decl then that causes LLDB
to go into an infinite loop.

I remember I added that second loop and the comment because I thought I saw a
similar pattern in some other Clang code, but after some grepping I can't find
that code anywhere and it seems the rest of the code base only calls
CompleteType once (It would also be kinda silly to have calling it multiple
times). So it seems that's just a silly mistake.

The is implicitly tested by importing `std::pair`, but I also added a simpler
dedicated test that creates a dummy libc++ module with some forward declarations
and then imports them into the scratch AST context. At some point the
ASTImporter will check if one of the forward decls could be completed by the
ExternalASTSource, which will cause the `SemaSourceWithPriorities` to go into an
infinite loop once it receives the `CompleteType` call.

Reviewed By: shafik

Differential Revision: https://reviews.llvm.org/D87289
2020-09-09 10:05:57 +02:00
Muhammad Omair Javaid 7695332166 Move NativeRegisterContextLinux/RegisterContextPOSIX*_arm to RegisterInfoAndSetInterface
This patch removes register set definitions and other redundant code from
NativeRegisterContextLinux/RegisterContextPOSIX*_arm. Register sets are now
moved under RegisterInfosPOSIX_arm which now uses RegisterInfoAndSetInterface.
This is similar to what we earlier did for AArch64.

Reviewed By: labath

Differential Revision: https://reviews.llvm.org/D86962
2020-09-07 09:06:46 +05:00
Raphael Isemann bdc4c0bc5c Revert "[lldb] avoid assert in threadsanitizer tests on linux"
This reverts commit f369d51896. The bug this
fixes was already fixed by 1c5a0cb1c3 with the
same approach and this commit is now just giving the variable a second fallback
value.
2020-09-04 09:30:56 +02:00
Luboš Luňák f369d51896 [lldb] avoid assert in threadsanitizer tests on linux
The tests are unsupported on linux, but they assert in
Thread::GetStopDescriptionRaw() because of empty stop reason
description. And it is empty because
InstrumentationRuntimeTSan::NotifyBreakpointHit() fails
to get report from InstrumentationRuntimeTSan::RetrieveReportData(),
which is possibly(?) the reason why this is unsupported on linux.
Add a dummy stop reason description for this case, which changes
the test result from failing to unsupported.
2020-09-03 21:18:17 +02:00
Med Ismail Bennani bf8f6e89c8 [lldb/Interpreter] Fix language detection for the REPL InitFile
Previously, before loading the REPL language-specific init file, lldb
checked the selected target language in which case it returned an unknown
language type with the REPL target.

Instead, the patch calls `Language::GetLanguagesSupportingREPLs` and
look for the first element of that set. In case lldb was not configured
with a REPL language, then, it will just stop sourcing the REPL init
file and fallback to the original logic (continuing with the default
init file).

rdar://65836048

Differential Revision: https://reviews.llvm.org/D87076

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2020-09-03 10:57:56 +02:00
Raphael Isemann 5b354d204d [lldb] Make symbol list output from `image dump symtab` not depend on internal ordering of DenseMap
`image dump symtab` seems to output the symbols in whatever order they appear in
the DenseMap that is used to filter out symbols with non-unique addresses. As
DenseMap is a hash map this order can change at any time so the output of this
command is pretty unstable. This also causes the `Breakpad/symtab.test` to fail
with enabled reverse iteration (which reverses the DenseMap order to find issues
like this).

This patch makes the DenseMap a std::vector and uses a separate DenseSet to do
the address filtering. The output order is now dependent on the order in which
the symbols are read (which should be deterministic). It might also avoid a bit
of work as all the work for creating the Symbol constructor parameters is only
done when we can actually emplace a new Symbol.

Reviewed By: labath

Differential Revision: https://reviews.llvm.org/D87036
2020-09-03 10:27:19 +02:00
Martin Storsjö 13cde6733b [lldb] Remove a stray semicolon, fixing pedantic GCC warnings. NFC. 2020-09-03 11:19:40 +03:00
Jonas Devlieghere 3746906193 [lldb] Add reproducer verifier
Add a reproducer verifier that catches:

 - Missing or invalid home directory
 - Missing or invalid working directory
 - Missing or invalid module/symbol paths
 - Missing files from the VFS

The verifier is enabled by default during replay, but can be skipped by
passing --reproducer-no-verify.

Differential revision: https://reviews.llvm.org/D86497
2020-09-02 22:00:00 -07:00
Jonas Devlieghere fa95e35593 [lldb] Pass -fno-objc-exceptions for objcxx targets
When compiling an Objective-C++ file, __has_feature(cxx_exceptions) will
return true with -fno-exceptions but without -fno-objc-exceptions. This
was causing LLVM_ENABLE_EXCEPTIONS to be defined for a subset of files.
2020-09-02 21:59:48 -07:00
Jonas Devlieghere 426fa35b65 [lldb] Always record both the working and home directory.
Treat the home directory like the current working directory and always
capture both in the VFS.
2020-09-02 20:53:11 -07:00
Jordan Rupprecht f7e04b710d [lldb/Gui] zero-initialize children_stop_id
This is currently causing msan warnings in the API tests when run under msan, e.g. `commands/gui/basic/TestGuiBasic.py`.

Reviewed By: clayborg

Differential Revision: https://reviews.llvm.org/D86825
2020-09-02 20:05:17 -07:00
Jordan Rupprecht c5aa63dd56 [lldb/Host] Add missing proc states
The /proc/<pid>/status parsing is missing a few cases:
- Idle
- Parked
- Dead

If we encounter an unknown proc state, this leads to an msan warning. In reality, we only check that the state != Zombie, so it doesn't really matter that we handle all cases, but handle them anyway (current list: [1]). Also explicitly set it to unknown if we encounter an unknown state. There will still be an msan warning if the proc entry has no `State:` line, but that should not happen.

Use a StringSwitch to make the handling of proc states a little more compact.

[1] https://github.com/torvalds/linux/blob/master/fs/proc/array.c

Reviewed By: labath

Differential Revision: https://reviews.llvm.org/D86818
2020-09-02 08:24:06 -07:00
Med Ismail Bennani addb5148f5 [lldb/Target] Add custom interpreter option to `platform shell`
This patch adds the ability to use a custom interpreter with the
`platform shell` command. If the user set the `-s|--shell` option
with the path to a binary, lldb passes it down to the platform's
`RunShellProcess` method and set it as the shell to use in
`ProcessLaunchInfo to run commands.

Note that not all the Platforms support running shell commands with
custom interpreters (i.e. RemoteGDBServer is only expected to use the
default shell).

This patch also makes some refactoring and cleanups, like swapping
CString for StringRef when possible and updating `SBPlatformShellCommand`
with new methods and a new constructor.

rdar://67759256

Differential Revision: https://reviews.llvm.org/D86667

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2020-09-02 16:36:10 +02:00
Jonas Devlieghere 9390b346fc [lldb] Move ScriptCommand and RegexCommand under Commands (NFC)
Move the CommandObjectScript and CommandObjectRegexCommand under
Commands where all the other CommandObject implementations live.

Although neither implementations currently use the TableGen-generated
CommandOptions.inc, this move would have been necessary anyway if they
were to in the future.
2020-09-01 17:33:39 -07:00
Med Ismail Bennani 0224738c1a [lldb/interpreter] Improve REPL init file compatibility
This patch changes the command interpreter sourcing logic for the REPL
init file. Instead of looking for a arbitrary file name, it standardizes
the REPL init file name to match to following scheme:

                          `.lldbinit-<language>-repl`

This will make the naming more homogenous and the sourcing logic future-proof.

rdar://65836048

Differential Revision: https://reviews.llvm.org/D86987

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2020-09-02 01:21:22 +02:00
Raphael Isemann 7c80f2da81 Revert "[lldb] Add reproducer verifier"
This reverts commit 297f69afac. It broke
the Fedora 33 x86-64 bot. See the review for more info.
2020-09-01 12:21:44 +02:00
Petr Hosek 3c7bfbd683 [CMake] Use find_library for ncurses
Currently it is hard to avoid having LLVM link to the system install of
ncurses, since it uses check_library_exists to find e.g. libtinfo and
not find_library or find_package.

With this change the ncurses lib is found with find_library, which also
considers CMAKE_PREFIX_PATH. This solves an issue for the spack package
manager, where we want to use the zlib installed by spack, and spack
provides the CMAKE_PREFIX_PATH for it.

This is a similar change as https://reviews.llvm.org/D79219, which just
landed in master.

Patch By: haampie

Differential Revision: https://reviews.llvm.org/D85820
2020-08-31 20:06:21 -07:00
Jonas Devlieghere 297f69afac [lldb] Add reproducer verifier
Add a reproducer verifier that catches:

 - Missing or invalid home directory
 - Missing or invalid working directory
 - Missing or invalid module/symbol paths
 - Missing files from the VFS

The verifier is enabled by default during replay, but can be skipped by
passing --reproducer-no-verify.

Differential revision: https://reviews.llvm.org/D86497
2020-08-31 15:14:18 -07:00
Gongyu Deng 1cd99fe9d4 [lldb] tab completion for class `CommandObjectTypeFormatterDelete`
1. Added a dedicated completion to class `CommandObjectTypeFormatterDelete`
   which can be used by these commands: `type filter/format/summary/synthetic delete`;
2. Added a related test case.

Reviewed By: teemperor

Differential Revision: https://reviews.llvm.org/D84142
2020-08-31 14:18:07 +02:00
Raphael Isemann 1c5a0cb1c3 [lldb] Don't crash when LLDB can't extract the tsan report
Right now all tsan tests are crashing on Linux. The tests were already marked as
expected failures, but since commit 20ce8affce added an assert that every
StopInfo needs a non-empty stop description the tests actually started crash
(which is even with an expectedFailure a failed test).

The reason for that is that we never had any stop description when hitting tsan
errors on Linux. Before the assert that just made the test fail, but now the
empty description is hitting the assert. This patch just adds a generic stop
description mentioning tsan to prevent that we hit that assert on platforms
where we don't support extracting the tsan report.

Reviewed By: friss

Differential Revision: https://reviews.llvm.org/D86593
2020-08-31 11:13:11 +02:00
Jonas Devlieghere cdc18163cd [lldb] Fix typo in disassemble_options_line description 2020-08-28 11:41:59 -07:00
Pavel Labath 9b50546b0b [lldb/Utility] Polish the Scalar class
This patch is mostly about removing the "Category" enum, which was
very useful when the Type enum contained a large number of types, but
now the two are completely identical.

It also removes some other artifacts like unused typedefs and macros.
2020-08-28 11:51:25 +02:00
Pavel Labath 1f9595ede4 [lldb] Reduce intentation in SymbolFileDWARF::ParseVariableDIE
using early exits. NFC.
2020-08-28 11:44:03 +02:00
Harmen Stoppels cdcb9ab10e Revert "Use find_library for ncurses"
The introduction of find_library for ncurses caused more issues than it solved problems. The current open issue is it makes the static build of LLVM fail. It is better to revert for now, and get back to it later.

Revert "[CMake] Fix an issue where get_system_libname creates an empty regex capture on windows"
This reverts commit 1ed1e16ab8.

Revert "Fix msan build"
This reverts commit 34fe9613dd.

Revert "[CMake] Always mark terminfo as unavailable on Windows"
This reverts commit 76bf26236f.

Revert "[CMake] Fix OCaml build failure because of absolute path in system libs"
This reverts commit 8e4acb82f7.

Revert "[CMake] Don't look for terminfo libs when LLVM_ENABLE_TERMINFO=OFF"
This reverts commit 495f91fd33.

Revert "Use find_library for ncurses"
This reverts commit a52173a3e5.

Differential revision: https://reviews.llvm.org/D86521
2020-08-27 17:57:26 -07:00
Pavel Labath 0de1463373 [lldb] Fix Type::GetByteSize for pointer types
The function was returning an incorrect (empty) value on the first
invocation. Given that this only affected the first invocation, this
bug/typo went mostly unaffected. DW_AT_const_value were particularly
badly affected by this as the GetByteSize call is
SymbolFileDWARF::ParseVariableDIE is likely to be the first call of this
function, and its effects cannot be undone by retrying.

Depends on D86348.

Differential Revision: https://reviews.llvm.org/D86436
2020-08-27 15:37:49 +02:00
Pavel Labath 9f5927e42b [lldb/DWARF] Fix handling of variables with both location and const_value attributes
Class-level static constexpr variables can have both DW_AT_const_value
(in the "declaration") and a DW_AT_location (in the "definition")
attributes. Our code was trying to handle this, but it was brittle and
hard to follow (and broken) because it was processing the attributes in
the order in which they were found.

Refactor the code to make the intent clearer -- DW_AT_location trumps
DW_AT_const_value, and fix the bug which meant that we were not
displaying these variables properly (the culprit was the delayed parsing
of the const_value attribute due to a need to fetch the variable type.

Differential Revision: https://reviews.llvm.org/D86615
2020-08-27 15:05:47 +02:00
Pavel Labath 219ccdfdde [lldb/Utility] Use APSInt in the Scalar class
This enables us to further simplify some code because it no longer needs
to switch on the signedness of the type (APSInt handles that).
2020-08-27 15:05:47 +02:00
David Spickett c1e6f1a7b1 [lldb] Fix gcc 5.4.0 compile error
Specify type when constructing PromotionKeys,
this fixes error:
"chosen constructor is explicit in copy-initialization"
when compiling lldb with GCC 5.4.0.

This is due to std::tuple having an explicit
default constructor, see:
http://cplusplus.github.io/LWG/lwg-defects.html#2193

Reviewed By: labath

Differential Revision: https://reviews.llvm.org/D86690
2020-08-27 10:23:05 +01:00
Greg Clayton c55db4600b Load correct module for linux and android when duplicates exist in minidump.
Breakpad creates minidump files that can a module loaded multiple times. We found that when a process mmap's the object file for a library, this can confuse breakpad into creating multiple modules in the module list. This patch fixes the GetFilteredModules() to check the linux maps for permissions and use the one that has execute permissions. Typically when people mmap a file into memory they don't map it as executable. This helps people to correctly load minidump files for post mortem analysis.

Differential Revision: https://reviews.llvm.org/D86375
2020-08-26 15:48:34 -07:00
Raphael Isemann 4a15f51a4f [lldb][NFC] Simplify string literal in GDBRemoteCommunicationClient 2020-08-26 16:25:11 +02:00
Pavel Labath 82982304d7 [lldb/DWARF] More DW_AT_const_value fixes
This fixes several issues in handling of DW_AT_const_value attributes:
- the first is that the size of the data given by data forms does not
  need to match the size of the underlying variable. We already had the
  case to handle this for DW_FORM_(us)data -- this extends the handling
  to other data forms. The main reason this was not picked up is because
  clang uses leb forms in these cases while gcc prefers the fixed-size
  ones.
- The handling of DW_AT_strp form was completely broken -- we would end
  up using the pointer value as the result. I've reorganized this code
  so that it handles all string forms uniformly.
- In case of a completely bogus form we would crash due to
  strlen(nullptr).

Depends on D86311.

Differential Revision: https://reviews.llvm.org/D86348
2020-08-26 13:17:26 +02:00
Jason Molenda 99d187a003 Update UnwindPlan dump to list if it is a trap handler func; also Command
Update the "image show-unwind" command output to show if the function
being shown is listed as a user-setting or platform trap handler.

Update the individual UnwindPlan dumps to show whether the unwind plan
is registered as a trap handler.
2020-08-25 20:53:59 -07:00
Jonas Devlieghere 521220690a [lldb] Make Reproducer compatbile with SubsystemRAII (NFC)
Make Reproducer compatbile with SubsystemRAII and use it in
LocateSymbolFileTest.
2020-08-25 13:00:04 -07:00
Muhammad Omair Javaid 4283320b72 [LLDB] Fix SVE offset calculation in NativeRegisterContextLinux_arm64
There was typo left from changes in CalculateSVEOffset where we moved
FPSR/FPCR offset calculation into WriteRegister and ReadRegister.

Differential Revision: https://reviews.llvm.org/D79699
2020-08-25 03:54:41 +05:00
shafik 93b255142b [LLDB] Fix how ValueObjectVariable handles DW_AT_const_value when the DWARFExpression holds the data that represents a constant value
In some cases when we have a DW_AT_const_value and the data can be found in the
DWARFExpression then ValueObjectVariable does not handle it properly and we end
up with an extracting data from value failed error.

The test is a very stripped down assembly file since reproducing this relies on the results of compiling with -O1 which may not be stable over time.

Differential Revision: https://reviews.llvm.org/D86311
2020-08-24 15:17:27 -07:00