90 Commits

Author SHA1 Message Date
Jonas Devlieghere
f28a497a06
[lldb] Support specifying a language for breakpoint conditions (#147603)
LLDB breakpoint conditions take an expression that's evaluated using the
language of the code where the breakpoint is located. Users have asked
to have an option to tell it to evaluate the expression in a specific
language.

This is feature is especially helpful for Swift, for example for a
condition based on the value in memory at an offset from a register.
Such a condition is pretty difficult to write in Swift, but easy in C.

This PR adds a new argument (-Y) to specify the language of the
condition expression. We can't reuse the current -L option, since you
might want to break on only Swift symbols, but run a C expression there
as per the example above.

rdar://146119507
2025-07-10 15:24:27 -07:00
Jonas Devlieghere
378f248934
[lldb] Add SB API to make a breakpoint a hardware breakpoint (#146602)
This adds SBBreakpoint::SetIsHardware, allowing clients to mark an
existing breakpoint as a hardware breakpoint purely through the API.
This is safe to do after creation, as the hardware/software distinction
doesn't affect how breakpoint locations are selected.

In some cases (e.g. when writing a trap instruction would alter program
behavior), it's important to use hardware breakpoints. Ideally, we’d
extend the various `Create` methods to support this, but given their
number, this patch limits the scope to the post-creation API. As a
workaround, users can also rely on target.require-hardware-breakpoint or
use the `breakpoint set` command.

rdar://153528045
2025-07-03 11:17:19 -07:00
Greg Clayton
c4fb7180cb
[lldb][NFC] Make the target's SectionLoadList private. (#113278)
Lots of code around LLDB was directly accessing the target's section
load list. This NFC patch makes the section load list private so the
Target class can access it, but everyone else now uses accessor
functions. This allows us to control the resolving of addresses and will
allow for functionality in LLDB which can lazily resolve addresses in
JIT plug-ins with a future patch.
2025-01-14 20:12:46 -08:00
Adrian Prantl
b798f4bd50
[lldb] Make deep copies of Status explicit (NFC) (#107170) 2024-09-05 12:44:13 -07:00
Adrian Prantl
0642cd768b
[lldb] Turn lldb_private::Status into a value type. (#106163)
This patch removes all of the Set.* methods from Status.

This cleanup is part of a series of patches that make it harder use the
anti-pattern of keeping a long-lives Status object around and updating
it while dropping any errors it contains on the floor.

This patch is largely NFC, the more interesting next steps this enables
is to:
1. remove Status.Clear()
2. assert that Status::operator=() never overwrites an error
3. remove Status::operator=()

Note that step (2) will bring 90% of the benefits for users, and step
(3) will dramatically clean up the error handling code in various
places. In the end my goal is to convert all APIs that are of the form

`    ResultTy DoFoo(Status& error)
`
to

`    llvm::Expected<ResultTy> DoFoo()
`
How to read this patch?

The interesting changes are in Status.h and Status.cpp, all other
changes are mostly

` perl -pi -e 's/\.SetErrorString/ = Status::FromErrorString/g' $(git
grep -l SetErrorString lldb/source)
`
plus the occasional manual cleanup.
2024-08-27 10:59:31 -07:00
Dhruv Srivastava
b804516dc5
[lldb][AIX] 1. Avoid namespace collision on other platforms (#104679)
This PR is in reference to porting LLDB on AIX.

Link to discussions on llvm discourse and github:
1.  https://discourse.llvm.org/t/port-lldb-to-ibm-aix/80640
2.  #101657 

The complete changes for porting are present in this draft PR:
https://github.com/llvm/llvm-project/pull/102601

The changes on this PR are intended to avoid namespace collision for
certain typedefs between lldb and other platforms:
1. tid_t --> lldb::tid_t
2. offset_t --> lldb::offset_t
2024-08-20 10:19:32 +01:00
Shivam Gupta
1e92ad41d8
[lldb] Use const reference for range variables to improve performance (NFC) (#94840)
Cppcheck recommends using a const reference for range variables in a
for-each loop.
This avoids unnecessary copying of elements, improving performance.

Caught by cppcheck -
lldb/source/API/SBBreakpoint.cpp:717:22: performance: Range variable
'name' should be declared as const reference. [iterateByValue]
lldb/source/API/SBTarget.cpp:1150:15: performance: Range variable 'name'
should be declared as const reference. [iterateByValue]
lldb/source/Breakpoint/Breakpoint.cpp:888:26: performance: Range
variable 'name' should be declared as const reference. [iterateByValue]
lldb/source/Breakpoint/BreakpointIDList.cpp:262:26: performance: Range
variable 'name' should be declared as const reference. [iterateByValue]

Fix #91213
Fix #91217
Fix #91219
Fix #91220
2024-06-08 22:34:40 +05:30
Alex Langford
f2d32ddcec [lldb] Sink StreamFile into lldbHost
StreamFile subclasses Stream (from lldbUtility) and is backed by a File
(from lldbHost). It does not depend on anything from lldbCore or any of its
sibling libraries, so I think it makes sense for this to live in
lldbHost instead.

Differential Revision: https://reviews.llvm.org/D157460
2023-08-09 17:17:18 -07:00
Alex Langford
41714c959d [lldb] Guarantee the lifetimes of all strings returned from SBAPI
LLDB should guarantee that the strings returned by SBAPI methods
live forever. I went through every method that returns a string and made
sure that it was added to the ConstString StringPool before returning if
it wasn't obvious that it was already doing so.
I've also updated the docs to document this behavior.

Differential Revision: https://reviews.llvm.org/D150804
2023-05-18 15:13:36 -07:00
Med Ismail Bennani
9a9fce1fed [lldb] Fix {break,watch}point command function stopping behaviour
In order to run a {break,watch}point command, lldb can resolve to the
script interpreter to run an arbitrary piece of code or call into a
user-provided function. To do so, we will generate a wrapping function,
where we first copy lldb's internal dictionary keys into the
interpreter's global dictionary, copied inline the user code before
resetting the global dictionary to its previous state.

However, {break,watch}point commands can optionally return a value that
would tell lldb whether we should stop or not. This feature was
only implemented for breakpoint commands and since we inlined the user
code directly into the wrapping function, introducing an early return,
that caused lldb to let the interpreter global dictionary tinted with the
internal dictionary keys.

This patch fixes that issue while also adding the stopping behaviour to
watchpoint commands.

To do so, this patch refactors the {break,watch}point command creation
method, to let the lldb wrapper function generator know if the user code is
a function call or a arbitrary expression.

Then the wrapper generator, if the user input was a function call, the
wrapper function will call the user function and save the return value into
a variable. If the user input was an arbitrary expression, the wrapper  will
inline it into a nested function, call the nested function and save the
return value into the same variable. After resetting the interpreter global
dictionary to its previous state, the generated wrapper function will return
the varible containing the return value.

rdar://105461140

Differential Revision: https://reviews.llvm.org/D144688

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2023-02-28 11:39:58 -08:00
Kazu Hirata
360c1111e3 Use llvm::is_contained (NFC) 2022-07-20 09:09:19 -07:00
Jonas Devlieghere
1755f5b1d7 [lldb] Decouple instrumentation from the reproducers
Remove the last remaining references to the reproducers from the
instrumentation. This patch renames the relevant files and macros.

Differential revision: https://reviews.llvm.org/D117712
2022-01-20 18:06:14 -08:00
Jonas Devlieghere
da4b7437f9 [lldb] Remove LLDB_RECORD_DUMMY_* macros 2022-01-10 12:05:54 -08:00
Jonas Devlieghere
d232abc33b [lldb] Remove LLDB_RECORD_RESULT macro 2022-01-09 22:54:17 -08:00
Jonas Devlieghere
d51402ac6b [lldb] Remove reproducer instrumentation
This patch removes most of the reproducer instrumentation. It keeps
around the LLDB_RECORD_* macros for logging. See [1] for more details.

[1] https://lists.llvm.org/pipermail/lldb-dev/2021-September/017045.html

Differential revision: https://reviews.llvm.org/D116847
2022-01-09 21:40:55 -08:00
Kazu Hirata
a3436f7340 [API] Remove redundant member initialization (NFC)
Identified with readability-redundant-member-init.
2022-01-02 22:44:16 -08:00
Jim Ingham
cfb96d845a Convert functions that were returning BreakpointOption * to BreakpointOption &.
This is an NFC cleanup.

Many of the API's that returned BreakpointOptions always returned valid ones.
Internally the BreakpointLocations usually have null BreakpointOptions, since they
use their owner's options until an option is set specifically on the location.
So the original code used pointers & unique_ptr everywhere for consistency.
But that made the code hard to reason about from the outside.

This patch changes the code so that everywhere an API is guaranteed to
return a non-null BreakpointOption, it returns it as a reference to make
that clear.

It also changes the Breakpoint to hold a BreakpointOption
member where it previously had a UP.  Since we were always filling the UP
in the Breakpoint constructor, having the UP wasn't helping anything.

Differential Revision: https://reviews.llvm.org/D104162
2021-06-15 14:34:02 -07:00
Jim Ingham
6754caa9bf Add an SB API to get the SBTarget from an SBBreakpoint
Differential Revision: https://reviews.llvm.org/D89358
2020-10-15 14:28:44 -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
d9d992bb88 [lldb/API] Add missing LLDB_RECORD_RESULT 2020-07-01 14:41:11 -07:00
Med Ismail Bennani
f70cad2612
[lldb/api] Improve error reporting in SBBreakpoint::AddName (NFCI)
This patch improves the error reporting for SBBreakpoint::AddName by
adding a new method `SBBreakpoint::AddNameWithErrorHandling` that returns
a SBError instead of a boolean.

This way, if the breakpoint naming failed in the backend, the client
(i.e. Xcode), will be able to report the reason of that failure to the
user.

rdar://64765461

Differential Revision: https://reviews.llvm.org/D82879

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2020-07-01 12:45:05 +02:00
Med Ismail Bennani
a61f62a7b6 Revert "[lldb/api] Improve error reporting in SBBreakpoint::AddName (NFCI)"
This reverts commit 56bb1d1755ae38b4e7a67f775978b18a601f215f.
2020-07-01 12:41:32 +02:00
Med Ismail Bennani
56bb1d1755 [lldb/api] Improve error reporting in SBBreakpoint::AddName (NFCI)
This patch improves the error reporting for SBBreakpoint::AddName by
adding a new method `SBBreakpoint::AddNameWithErrorHandling` that returns
a SBError instead of a boolean.

This way, if the breakpoint naming failed in the backend, the client
(i.e. Xcode), will be able to report the reason of that failure to the
user.

rdar://64765461

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
2020-07-01 12:37:00 +02:00
Jonas Devlieghere
866b7a6519 [lldb] Replace empty ctor en dtor bodies with =default (NFC)
Use = default instead of empty constructor and destructor bodies in the
API layer.
2020-02-17 22:58:26 -08:00
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
Jim Ingham
738af7a624 Add the ability to pass extra args to a Python breakpoint callback.
For example, it is pretty easy to write a breakpoint command that implements "stop when my caller is Foo", and
    it is pretty easy to write a breakpoint command that implements "stop when my caller is Bar". But there's no
    way to write a generic "stop when my caller is..." function, and then specify the caller when you add the
    command to a breakpoint.

    With this patch, you can pass this data in a SBStructuredData dictionary. That will get stored in
    the PythonCommandBaton for the breakpoint, and passed to the implementation function (if it has the right
    signature) when the breakpoint is hit. Then in lldb, you can say:

    (lldb) break com add -F caller_is -k caller_name -v Foo

    More generally this will allow us to write reusable Python breakpoint commands.

    Differential Revision: https://reviews.llvm.org/D68671
2019-10-25 14:05:07 -07:00
Jonas Devlieghere
2b29b432d2 [ScriptInterpreter] Move ownership into debugger (NFC)
This is part two of the change started in r359330. This patch moves the
ownership of the script interpreter from the command interpreter into
the debugger. I would've preferred to remove the lazy initialization,
however the fact that the scripting language is set after the debugger
is created makes that tricky. So for now this does exactly the same
thing as when it was under the command interpreter. The result is that
this patch is fully NFC.

Differential revision: https://reviews.llvm.org/D61211

llvm-svn: 359354
2019-04-26 22:43:16 +00:00
Jonas Devlieghere
306809f292 [Reproducers] Capture return values of functions returning by ptr/ref
For some reason I had convinced myself that functions returning by
pointer or reference do not require recording their result. However,
after further considering I don't see how that could work, at least not
with the current implementation. Interestingly enough, the reproducer
instrumentation already (mostly) accounts for this, though the
lldb-instr tool did not.

This patch adds the missing macros and updates the lldb-instr tool.

Differential revision: https://reviews.llvm.org/D60178

llvm-svn: 357639
2019-04-03 21:31:22 +00:00
Michal Gorny
ae211ece6a [lldb] [Reproducer] Move SBRegistry registration into declaring files
Move SBRegistry method registrations from SBReproducer.cpp into files
declaring the individual APIs, in order to reduce the memory consumption
during build and improve maintainability.  The current humongous
SBRegistry constructor exhausts all memory on a NetBSD system with 4G
RAM + 4G swap, therefore making it impossible to build LLDB.

Differential Revision: https://reviews.llvm.org/D59427

llvm-svn: 356481
2019-03-19 17:13:13 +00:00
Pavel Labath
7f5237bccc Add "operator bool" to SB APIs
Summary:
Our python version of the SB API has (the python equivalent of)
operator bool, but the C++ version doesn't.

This is because our python operators are added by modify-python-lldb.py,
which performs postprocessing on the swig-generated interface files.

In this patch, I add the "operator bool" to all SB classes which have an
IsValid method (which is the same logic used by modify-python-lldb.py).
This way, we make the two interfaces more constent, and it allows us to
rely on swig's automatic syntesis of python __nonzero__ methods instead
of doing manual fixups.

Reviewers: zturner, jingham, clayborg, jfb, serge-sans-paille

Subscribers: jdoerfert, lldb-commits

Differential Revision: https://reviews.llvm.org/D58792

llvm-svn: 355824
2019-03-11 13:58:46 +00:00
Jonas Devlieghere
0d7b0c960d [Reproducers] Add missing LLDB_RECORD_DUMMY macros
Re-ran lldb-inst on the API folder to insert missing LLDB_RECORD_DUMMY
macros.

llvm-svn: 355711
2019-03-08 19:09:27 +00:00
Jonas Devlieghere
581af8b09d [SBAPI] Log from record macro
The current record macros already log the function being called. This
patch extends the macros to also log their input arguments and removes
explicit logging from the SB API.

This might degrade the amount of information in some cases (because of
smarter casts or efforts to log return values). However I think this is
outweighed by the increased coverage and consistency. Furthermore, using
the reproducer infrastructure, diagnosing bugs in the API layer should
become much easier compared to relying on log messages.

Differential revision: https://reviews.llvm.org/D59101

llvm-svn: 355649
2019-03-07 22:47:13 +00:00
Jonas Devlieghere
baf5664f50 [Reproducers] Add SBReproducer macros
This patch adds the SBReproducer macros needed to capture and reply the
corresponding calls. This patch was generated by running the lldb-instr
tool on the API source files.

Differential revision: https://reviews.llvm.org/D57475

llvm-svn: 355459
2019-03-06 00:06:00 +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
e103ae92ef Add setting to require hardware breakpoints.
When debugging read-only memory we cannot use software breakpoint. We
already have support for hardware breakpoints and users can specify them
with `-H`. However, there's no option to force LLDB to use hardware
breakpoints internally, for example while stepping.

This patch adds a setting target.require-hardware-breakpoint that forces
LLDB to always use hardware breakpoints. Because hardware breakpoints
are a limited resource and can fail to resolve, this patch also extends
error handling in thread plans, where breakpoints are used for stepping.

Differential revision: https://reviews.llvm.org/D54221

llvm-svn: 346920
2018-11-15 01:18:15 +00:00
Jonas Devlieghere
ceff6644bb Remove header grouping comments.
This patch removes the comments grouping header includes. They were
added after running IWYU over the LLDB codebase. However they add little
value, are often outdates and burdensome to maintain.

llvm-svn: 346626
2018-11-11 23:17:06 +00:00
Jim Ingham
3815e702e7 Add a "scripted" breakpoint type to lldb.
This change allows you to write a new breakpoint type where the
logic for setting breakpoints is determined by a Python callback
written using the SB API's.

Differential Revision: https://reviews.llvm.org/D51830

llvm-svn: 342185
2018-09-13 21:35:32 +00:00
Jim Ingham
b842f2ecf0 Make breakpoint names real entities.
When introduced, breakpoint names were just tags that you could
apply to breakpoints that would allow you to refer to a breakpoint
when you couldn't capture the ID, or to refer to a collection of
breakpoints.  

This change makes the names independent holders of breakpoint options
that you can then apply to breakpoints when you add the name to the
breakpoint.  It adds the "breakpoint name configure" command to set
up or reconfigure breakpoint names.  There is also full support for
then in the SB API, including a new SBBreakpointName class.

The connection between the name and the breakpoints
sharing the name remains live, so if you reconfigure the name, all the
breakpoint options all change as well.  This allows a quick way
to share complex breakpoint behavior among a bunch of breakpoints, and
a convenient way to iterate on the set.

You can also create a name from a breakpoint, allowing a quick way
to copy options from one breakpoint to another.

I also added the ability to make hidden and delete/disable protected
names.  When applied to a breakpoint, you will only be able to list,
delete or disable that breakpoint if you refer to it explicitly by ID.

This feature will allow GUI's that need to use breakpoints for their
own purposes to keep their breakpoints from getting accidentally 
disabled or deleted.

<rdar://problem/22094452>

llvm-svn: 313292
2017-09-14 20:22:49 +00:00
Jim Ingham
1c7dc829bc Cut and paste error from r23162.
llvm-svn: 309977
2017-08-03 19:38:38 +00:00
Jim Ingham
f08f5c9926 Add an auto-continue flag to breakpoints & locations.
You can get a breakpoint to auto-continue by adding "continue"
as a command, but that has the disadvantage that if you hit two
breakpoints simultaneously, the continue will force the process
to continue, and maybe even forstalling the commands on the other.
The auto-continue flag means the breakpoints can negotiate about
whether to stop.

Writing tests, I wanted to supply some commands when I made the
breakpoints, so I also added that ability.

llvm-svn: 309969
2017-08-03 18:13:24 +00:00
Zachary Turner
97206d5727 Rename Error -> Status.
This renames the LLDB error class to Status, as discussed
on the lldb-dev mailing list.

A change of this magnitude cannot easily be done without
find and replace, but that has potential to catch unwanted
occurrences of common strings such as "Error".  Every effort
was made to find all the obvious things such as the word "Error"
appearing in a string, etc, but it's possible there are still
some lingering occurences left around.  Hopefully nothing too
serious.

llvm-svn: 302872
2017-05-12 04:51:55 +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
Pavel Labath
6ac8403430 Switch SBBreakpoint to storing a weak_ptr of the internal breakpoint object
Summary:
There is nothing we can do with the breakpoint once the associated
target becomes deleted. This will make sure we don't hold on to more
resources than we need in this case. In particular, this fixes the case
TestStepOverBreakpoint on windows, where a lingering SBBreakpoint object
causes us to nor unmap the executable file from memory.

Reviewers: clayborg, jingham

Subscribers: lldb-commits

Differential Revision: https://reviews.llvm.org/D30249

llvm-svn: 296328
2017-02-27 11:05:34 +00:00
Zachary Turner
bf9a77305f Move classes from Core -> Utility.
This moves the following classes from Core -> Utility.

ConstString
Error
RegularExpression
Stream
StreamString

The goal here is to get lldbUtility into a state where it has
no dependendencies except on itself and LLVM, so it can be the
starting point at which to start untangling LLDB's dependencies.
These are all low level and very widely used classes, and
previously lldbUtility had dependencies up to lldbCore in order
to use these classes.  So moving then down to lldbUtility makes
sense from both the short term and long term perspective in
solving this problem.

Differential Revision: https://reviews.llvm.org/D29427

llvm-svn: 293941
2017-02-02 21:39:50 +00:00
Todd Fiala
653e3f4e19 Remove weak-linked symbols for SBBreakpointListImpl
Summary:
Similar to SBStructuredData's Impl class, SBBreakpointListImpl was
getting weak-link exported in the lldb namespace. This change list fixes
that by moving out of the lldb public namespace, which removes it from
public export visibility.

Fixes:
rdar://28960344

Reviewers: jingham

Subscribers: lldb-commits

Differential Revision: https://reviews.llvm.org/D26553

llvm-svn: 286631
2016-11-11 21:06:40 +00:00
Jim Ingham
f7e0725628 Fix serialization of Python breakpoint commands.
CommandData breakpoint commands didn't know whether they were
Python or Command line commands, so they couldn't serialize &
deserialize themselves properly.  Fix that.
I also changed the "breakpoint list" command to note in the output
when the commands are Python commands.  Fortunately only one test
was relying on this explicit bit of text output.

llvm-svn: 282432
2016-09-26 19:47:37 +00:00
Jim Ingham
92d1960e3b Add some more tests for breakpoint serialization.
Serialize breakpoint names & the hardware_requested attributes.
Also added a few missing affordances to SBBreakpoint whose absence
writing the tests pointed out.

<rdar://problem/12611863>

llvm-svn: 282036
2016-09-20 22:54:49 +00:00
Jim Ingham
6d1e4696a2 First tests for serializing breakpoints.
Plus a few bug fixes I found along the way.

llvm-svn: 281690
2016-09-16 01:41:27 +00:00
Jim Ingham
01f1666471 Add SB API's for writing breakpoints to & creating the from a file.
Moved the guts of the code from CommandObjectBreakpoint to Target (should
have done it that way in the first place.)  Added an SBBreakpointList class
so there's a way to specify which breakpoints to serialize and to report the
deserialized breakpoints.

<rdar://problem/12611863> 

llvm-svn: 281520
2016-09-14 19:07:35 +00:00
Zachary Turner
4e4fbe8211 Some more pointer safety in Breakpoint.
Plumb unique_ptrs<> all the way through the baton interface.
NFC, this is a minor improvement to remove the possibility of an
accidental pointer ownership issue.

Reviewed By: jingham
Differential Revision: https://reviews.llvm.org/D24495

llvm-svn: 281360
2016-09-13 17:53:38 +00:00