Commit Graph

74 Commits

Author SHA1 Message Date
Arthur Eubanks d002cd4e0f [test] Move coro-retcon-unreachable.ll into llvm/test
Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D94257
2021-01-07 14:06:01 -08:00
Fangrui Song fd739804e0 [test] Add {{.*}} to make ELF tests immune to dso_local/dso_preemptable/(none) differences
For a default visibility external linkage definition, dso_local is set for ELF
-fno-pic/-fpie and COFF and Mach-O. Since default clang -cc1 for ELF is similar
to -fpic ("PIC Level" is not set), this nuance causes unneeded binary format differences.

To make emitted IR similar, ELF -cc1 -fpic will default to -fno-semantic-interposition,
which sets dso_local for default visibility external linkage definitions.

To make this flip smooth and enable future (dso_local as definition default),
this patch replaces (function) `define ` with `define{{.*}} `,
(variable/constant/alias) `= ` with `={{.*}} `, or inserts appropriate `{{.*}} `.
2020-12-31 00:27:11 -08:00
CJ Johnson 69cd776e1e [CodeGen] Apply 'nonnull' and 'dereferenceable(N)' to 'this' pointer
arguments.

* Adds 'nonnull' and 'dereferenceable(N)' to 'this' pointer arguments
* Gates 'nonnull' on -f(no-)delete-null-pointer-checks
* Introduces this-nonnull.cpp and microsoft-abi-this-nullable.cpp tests to
  explicitly test the behavior of this change
* Refactors hundreds of over-constrained clang tests to permit these
  attributes, where needed
* Updates Clang12 patch notes mentioning this change

Reviewed-by: rsmith, jdoerfert

Differential Revision: https://reviews.llvm.org/D17993
2020-11-16 17:39:17 -08:00
Xun Li 19f0770923 [Coroutine][Sema] Cleanup temporaries as early as possible
The original bug was discovered in T75057860. Clang front-end emits an AST that looks like this for an co_await expression:
|- ExprWithCleanups
  |- -CoawaitExpr
    |- -MaterializeTemporaryExpr ... Awaiter
      ...
    |- -CXXMemberCallExpr ... .await_ready
      ...
    |- -CallExpr ... __builtin_coro_resume
      ...
    |- -CXXMemberCallExpr ... .await_resume
      ...

ExprWithCleanups is responsible for cleaning up (including calling dtors) for the temporaries generated in the wrapping expression).
In the above structure, the __builtin_coro_resume part (which corresponds to the code for the suspend case in the co_await with symmetric transfer), the pseudocode looks like this:
  __builtin_coro_resume(
   awaiter.await_suspend(
     from_address(
       __builtin_coro_frame())).address());

One of the temporaries that's generated as part of this code is the coroutine handle returned from awaiter.await_suspend() call. The call returns a handle  which is a prvalue (since it's a returned value on the fly). In order to call the address() method on it, it needs to be converted into an xvalue. Hence a materialized temp is created to hold it. This temp will need to be cleaned up eventually. Now, since all cleanups happen at the end of the entire co_await expression, which is after the <coro.suspend> suspension point, the compiler will think that such a temp needs to live across suspensions, and need to be put on the coroutine frame, even though it's only used temporarily just to call address() method.
Such a phenomena not only unnecessarily increases the frame size, but can lead to ASAN failures, if the coroutine was already destroyed as part of the await_suspend() call. This is because if the coroutine was already destroyed, the frame no longer exists, and one can not store anything into it. But if the temporary object is considered to need to live on the frame, it will be stored into the frame after await_suspend() returns.

A fix attempt was done in https://reviews.llvm.org/D87470. Unfortunately it is incorrect. The reason is that cleanups in Clang works more like linearly than nested. There is one current state indicating whether it needs cleanup, and an ExprWithCleanups resets that state. This means that an ExprWithCleanups must be capable of cleaning up all temporaries created  in the wrapping expression, otherwise there will be dangling temporaries cleaned up at the wrong place.
I eventually found a walk-around (https://reviews.llvm.org/D89066) that doesn't break any existing tests while fixing the issue. But it targets the final co_await only. If we ever have a co_await that's not on the final awaiter and the frame gets destroyed after suspend, we are in trouble. Hence we need a proper fix.

This patch is the proper fix. It does the folllowing things to fully resolve the issue:
1. The AST has to be generated in the order according to their nesting relationship. We should not generate AST out of order because then the code generator would incorrectly track the state of temporaries and when a cleanup is needed. So the code in buildCoawaitCalls is reorganized so that we will be generating the AST for each coawait member call in order along with their child AST.
2. await_ready() call is wrapped with an ExprWithCleanups so that temporaries in it gets cleaned up as early as possible to avoid living across suspension.
3. await_suspend() call is wrapped with an ExprWithCleanups if it's not a symmetric transfer. In the case of a symmetric transfer, in order to maintain the musttail call contract, the ExprWithCleanups is wraaped before the resume call.
4. In the end, we mark again that it needs a cleanup, so that the entire CoawaitExpr will be wrapped with a ExprWithCleanups which will clean up the Awaiter object associated with the await expression.

Differential Revision: https://reviews.llvm.org/D90990
2020-11-10 13:27:42 -08:00
Matt Arsenault 0a7cd99a70 Reapply "OpaquePtr: Add type to sret attribute"
This reverts commit eb9f7c28e5.

Previously this was incorrectly handling linking of the contained
type, so this merges the fixes from D88973.
2020-10-16 11:05:02 -04:00
Xun Li d80ecdf27f [Coroutine] Rename coro-semmetric-transfer.cpp and possibly fix test failure
Some tests start to fail after https://reviews.llvm.org/D89066.
It's because the size of pointers are different on different targets.
Limit the target in the command so there is no confusion.
Also noticed I had typo in the test name.
Adding disable-llvm-passes option to make the test more stable as well.

Differential Revision: https://reviews.llvm.org/D89269
2020-10-12 15:29:07 -07:00
Xun Li dce8f2bb25 [Coroutine][Sema] Only tighten the suspend call temp lifetime for final awaiter
In https://reviews.llvm.org/D87470 I added the change to tighten the lifetime of the expression awaiter.await_suspend().address.
Howver it was incorrect. ExprWithCleanups will call the dtor and end the lifetime for all the temps created in the current full expr.
When this is called on a normal await call, we don't want to do that.
We only want to do this for the call on the final_awaiter, to avoid writing into the frame after the frame is destroyed.
This change fixes it, by checking IsImplicit.

Differential Revision: https://reviews.llvm.org/D89066
2020-10-12 12:00:20 -07:00
Tres Popp eb9f7c28e5 Revert "OpaquePtr: Add type to sret attribute"
This reverts commit 55c4ff91bd.

Issues were introduced as discussed in https://reviews.llvm.org/D88241
where this change made previous bugs in the linker and BitCodeWriter
visible.
2020-09-29 10:31:04 +02:00
Matt Arsenault 55c4ff91bd OpaquePtr: Add type to sret attribute
Make the corresponding change that was made for byval in
b7141207a4. Like byval, this requires a
bulk update of the test IR tests to include the type before this can
be mandatory.
2020-09-25 14:07:30 -04:00
Xun Li df477db5f9 [Coroutine][Sema] Tighten the lifetime of symmetric transfer returned handle
In generating the code for symmetric transfer, a temporary object is created to store the returned handle from await_suspend() call of the awaiter. Previously this temp won't be cleaned up until very later, which ends up causing this temp to be spilled to the heap. However, we know that this temp will no longer be needed after the coro_resume call. We can clean it up right after.

Differential Revision: https://reviews.llvm.org/D87470
2020-09-11 13:35:37 -07:00
Xun Li 516803dc86 [Coroutines] Ensure co_await promise.final_suspend() does not throw
Summary:
This patch addresses https://bugs.llvm.org/show_bug.cgi?id=46256
The spec of coroutine requires that the expression co_­await promise.final_­suspend() shall not be potentially-throwing.
To check this, we recursively look at every call (including Call, MemberCall, OperatorCall and Constructor) in all code
generated by the final suspend, and ensure that the callees are declared with noexcept. We also look at any returned data
type that requires explicit destruction, and check their destructors for noexcept.

This patch does not check declarations with dependent types yet, which will be done in future patches.

Updated all tests to add noexcept to the required functions, and added a dedicated test for this patch.

This patch might start to cause existing codebase fail to compile because most people may not have been strict in tagging
all the related functions noexcept.

Reviewers: lewissbaker, modocache, junparser

Reviewed By: modocache

Subscribers: arphaman, junparser, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D82029
2020-06-22 15:01:42 -07:00
Eli Friedman 62f3ef2b53 [CGCall] Annotate references with "align" attribute.
If we're going to assume references are dereferenceable, we should also
assume they're aligned: otherwise, we can't actually dereference them.

See also D80072.

Differential Revision: https://reviews.llvm.org/D80166
2020-05-19 20:21:30 -07:00
Erik Pilkington de98cf92e3 [CodeGen] Add an alignment attribute to all sret parameters
This fixes a miscompile when the parameter is actually underaligned.
rdar://58316406

Differential revision: https://reviews.llvm.org/D74183
2020-03-24 15:31:57 -04:00
Jun Ma d0f4af8f30 [Coroutines] Insert lifetime intrinsics even O0 is used
Differential Revision: https://reviews.llvm.org/D76119
2020-03-24 13:41:55 +08:00
Jun Ma 53c2e10fb8 [Coroutines] Do not evaluate InitListExpr of a co_return
Differential Revision: https://reviews.llvm.org/D76118
2020-03-16 12:42:44 +08:00
Jun Ma 624dbfcc1b [Coroutines][New pass manager] Move CoroElide pass to right position
Differential Revision: https://reviews.llvm.org/D75345
2020-03-01 21:48:24 +08:00
Roman Lebedev 3dd5a298bf
[clang] Annotating C++'s `operator new` with more attributes
Summary:
Right now we annotate C++'s `operator new` with `noalias` attribute,
which very much is healthy for optimizations.

However as per [[ http://eel.is/c++draft/basic.stc.dynamic.allocation | `[basic.stc.dynamic.allocation]` ]],
there are more promises on global `operator new`, namely:
* non-`std::nothrow_t` `operator new` *never* returns `nullptr`
* If `std::align_val_t align` parameter is taken, the pointer will also be `align`-aligned
* ~~global `operator new`-returned pointer is `__STDCPP_DEFAULT_NEW_ALIGNMENT__`-aligned ~~ It's more caveated than that.

Supplying this information may not cause immediate landslide effects
on any specific benchmarks, but it for sure will be healthy for optimizer
in the sense that the IR will better reflect the guarantees provided in the source code.

The caveat is `-fno-assume-sane-operator-new`, which currently prevents emitting `noalias`
attribute, and is automatically passed by Sanitizers ([[ https://bugs.llvm.org/show_bug.cgi?id=16386 | PR16386 ]]) - should it also cover these attributes?
The problem is that the flag is back-end-specific, as seen in `test/Modules/explicit-build-flags.cpp`.
But while it is okay to add `noalias` metadata in backend, we really should be adding at least
the alignment metadata to the AST, since that allows us to perform sema checks on it.

Reviewers: erichkeane, rjmccall, jdoerfert, eugenis, rsmith

Reviewed By: rsmith

Subscribers: xbolva00, jrtc27, atanasyan, nlopes, cfe-commits

Tags: #llvm, #clang

Differential Revision: https://reviews.llvm.org/D73380
2020-02-26 01:37:17 +03:00
Brian Gesiak 048239e46e [Coroutines][6/6] Clang schedules new passes
Summary:
Depends on https://reviews.llvm.org/D71902.

The last in a series of six patches that ports the LLVM coroutines
passes to the new pass manager infrastructure.

This patch has Clang schedule the new coroutines passes when the
`-fexperimental-new-pass-manager` option is used. With this and the
previous 5 patches, Clang is capable of building and successfully
running the test suite of large coroutines projects such as
https://github.com/lewissbaker/cppcoro with
`ENABLE_EXPERIMENTAL_NEW_PASS_MANAGER=On`.

Reviewers: GorNishanov, lewissbaker, chandlerc, junparser

Subscribers: EricWF, cfe-commits, llvm-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D71903
2020-02-19 01:03:28 -05:00
Fangrui Song dbc96b518b Revert "[CodeGenModule] Assume dso_local for -fpic -fno-semantic-interposition"
This reverts commit 789a46f2d7.

Accidentally committed.
2020-02-03 10:09:39 -08:00
Fangrui Song 789a46f2d7 [CodeGenModule] Assume dso_local for -fpic -fno-semantic-interposition
Summary:
Clang -fpic defaults to -fno-semantic-interposition (GCC -fpic defaults
to -fsemantic-interposition).
Users need to specify -fsemantic-interposition to get semantic
interposition behavior.

Semantic interposition is currently a best-effort feature. There may
still be some cases where it is not handled well.

Reviewers: peter.smith, rnk, serge-sans-paille, sfertile, jfb, jdoerfert

Subscribers: dschuff, jyknight, dylanmckay, nemanjai, jvesely, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, sabuasal, niosHD, jrtc27, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, arphaman, PkmX, jocewei, jsji, Jim, lenary, s.egerton, pzheng, sameer.abuasal, apazos, luismarques, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D73865
2020-02-03 09:52:48 -08:00
John McCall 5f60b68c68 Remove unreachable blocks before splitting a coroutine.
The suspend-crossing algorithm is not correct in the presence of uses
that cannot be reached on some successor path from their defs.

llvm-svn: 368796
2019-08-14 03:54:13 +00:00
Tim Northover a009a60a91 IR: print value numbers for unnamed function arguments
For consistency with normal instructions and clarity when reading IR,
it's best to print the %0, %1, ... names of function arguments in
definitions.

Also modifies the parser to accept IR in that form for obvious reasons.

llvm-svn: 367755
2019-08-03 14:28:34 +00:00
Sean Fertile d900dd0c23 Revert "[CodeGenCXX] Treat 'this' as noalias in constructors"
This reverts commit https://reviews.llvm.org/rL344150 which causes
MachineOutliner related failures on the ppc64le multistage buildbot.

llvm-svn: 344526
2018-10-15 15:43:00 +00:00
Anton Bikineev cc7e74753a [CodeGenCXX] Treat 'this' as noalias in constructors
This is currently a clang extension and a resolution
of the defect report in the C++ Standard.

Differential Revision: https://reviews.llvm.org/D46441

llvm-svn: 344150
2018-10-10 16:14:51 +00:00
Brian Gesiak 12728474b3 [Coroutines] Less IR for noexcept await_resume
Summary:
In his review of https://reviews.llvm.org/D45860, @GorNishanov suggested
avoiding generating additional exception-handling IR in the case that
the resume function was marked as 'noexcept', and exceptions could not
occur. This implements that suggestion.

Test Plan: `check-clang`

Reviewers: GorNishanov, EricWF

Reviewed By: GorNishanov

Subscribers: cfe-commits, GorNishanov

Differential Revision: https://reviews.llvm.org/D47673

llvm-svn: 335422
2018-06-23 18:57:26 +00:00
Gor Nishanov 07ac63f89e [coroutines] Pass implicit object parameter to promise ctor (fix BUG37604)
Summary:
Complete the implementation of p0914r1.
Implicit object parameter should be passed to a promise constructor.

Fixes: https://bugs.llvm.org/show_bug.cgi?id=37604

Reviewers: modocache, rsmith, lewissbaker

Reviewed By: modocache

Subscribers: cfe-commits, EricWF

Differential Revision: https://reviews.llvm.org/D47454

llvm-svn: 333379
2018-05-28 18:08:47 +00:00
Brian Gesiak ea9144e818 [Coroutines] Catch exceptions in await_resume
Summary:
http://wg21.link/P0664r2 section "Evolution/Core Issues 24" describes a
proposed change to Coroutines TS that would have any exceptions thrown
after the initial suspend point of a coroutine be caught by the handler
specified by the promise type's 'unhandled_exception' member function.
This commit provides a sample implementation of the specified behavior.

Test Plan: `check-clang`

Reviewers: GorNishanov, EricWF

Reviewed By: GorNishanov

Subscribers: cfe-commits, lewissbaker, eric_niebler

Differential Revision: https://reviews.llvm.org/D45860

llvm-svn: 331519
2018-05-04 14:02:37 +00:00
Gor Nishanov 2a78fa5209 [coroutines] Add __builtin_coro_noop => llvm.coro.noop
A recent addition to Coroutines TS (https://wg21.link/p0913) adds a pre-defined
coroutine noop_coroutine that does nothing. To implement this feature, we implemented
an llvm.coro.noop intrinsic that returns a coroutine handle to a coroutine that
does nothing when resumed or destroyed.

This patch adds a builtin __builtin_coro_noop() that maps to llvm.coro.noop intrinsic.

Related llvm change: https://reviews.llvm.org/D45114

llvm-svn: 328993
2018-04-02 17:35:37 +00:00
Brian Gesiak cb02402489 [Coroutines] Find custom allocators in class scope
Summary:
https://reviews.llvm.org/rL325291 implemented Coroutines TS N4723
section [dcl.fct.def.coroutine]/7, but it performed lookup of allocator
functions within both the global and class scope, whereas the specified
behavior is to perform lookup for custom allocators within just the
class scope.

To fix, add parameters to the `Sema::FindAllocationFunctions` function
such that it can be used to lookup allocators in global scope,
class scope, or both (instead of just being able to look up in just global
scope or in both global and class scope). Then, use those parameters
from within the coroutine Sema.

This incorrect behavior had the unfortunate side-effect of causing the
bug https://bugs.llvm.org/show_bug.cgi?id=36578 (or at least the reports
of that bug in C++ programs). That bug would occur for any C++ user with
a coroutine frame that took a single pointer argument, since it would
then find the global placement form `operator new`, described in the
C++ standard 18.6.1.3.1. This patch prevents Clang from generating code
that triggers the LLVM assert described in that bug report.

Test Plan: `check-clang`

Reviewers: GorNishanov, eric_niebler, lewissbaker

Reviewed By: GorNishanov

Subscribers: EricWF, cfe-commits

Differential Revision: https://reviews.llvm.org/D44552

llvm-svn: 328949
2018-04-01 22:59:22 +00:00
Reid Kleckner fb93154bf1 [MS] Don't escape MS C++ names with \01
It is not needed after LLVM r327734. Now it will be easier to copy-paste
IR symbol names from Clang.

llvm-svn: 327738
2018-03-16 20:36:49 +00:00
Reid Kleckner ae9b070111 [MS] Always use base dtors in place of complete/vbase dtors when possible
Summary:
Previously we tried too hard to uphold the fiction that destructor
variants work like they do on Itanium throughout the ABI-neutral parts
of clang. This lead to MS C++ ABI incompatiblities and other bugs. Now,
-mconstructor-aliases will no longer control this ABI detail, and clang
-cc1's LLVM IR output will be this much closer to the clang driver's.

Based on a patch by Zahira Ammarguellat:
  https://reviews.llvm.org/D39063

I've tried to move the logic that Zahira added into MicrosoftCXXABI.cpp.
There is only one ABI-specific detail sticking out, and that is in
CodeGenModule::getAddrOfCXXStructor, where we collapse complete dtors to
base dtors in the MS ABI.

This fixes PR32990.

Reviewers: erichkeane, zahiraam, majnemer, rjmccall

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D44505

llvm-svn: 327732
2018-03-16 19:40:50 +00:00
Rafael Espindola 922f2aa9b2 Bring r325915 back.
The tests that failed on a windows host have been fixed.

Original message:

Start setting dso_local for COFF.

With this there are still some GVs where we don't set dso_local
because setGVProperties is never called. I intend to fix that in
followup commits. This is just the bare minimum to teach
shouldAssumeDSOLocal what it should do for COFF.

llvm-svn: 325940
2018-02-23 19:30:48 +00:00
Rafael Espindola 43ce3a3a4d Revert "Start setting dso_local for COFF."
This reverts commit r325915.

It will take some time to fix the failures on a windows host.

llvm-svn: 325929
2018-02-23 18:09:29 +00:00
Rafael Espindola 004d240b6a Start setting dso_local for COFF.
With this there are still some GVs where we don't set dso_local
because setGVProperties is never called. I intend to fix that in
followup commits. This is just the bare minimum to teach
shouldAssumeDSOLocal what it should do for COFF.

llvm-svn: 325915
2018-02-23 15:32:32 +00:00
Brian Gesiak 986062219f [Coroutines] Use allocator overload when available
Summary:
Depends on https://reviews.llvm.org/D42605.

An implementation of the behavior described in `[dcl.fct.def.coroutine]/7`:
when a promise type overloads `operator new` using a "placement new"
that takes the same argument types as the coroutine function, that
overload is used when allocating the coroutine frame.

Simply passing references to the coroutine function parameters directly
to `operator new` results in invariant violations in LLVM's coroutine
splitting pass, so this implementation modifies Clang codegen to
produce allocator-specific alloc/store/loads for each parameter being
forwarded to the allocator.

Test Plan: `check-clang`

Reviewers: rsmith, GorNishanov, eric_niebler

Reviewed By: GorNishanov

Subscribers: lewissbaker, EricWF, cfe-commits

Differential Revision: https://reviews.llvm.org/D42606

llvm-svn: 325291
2018-02-15 20:37:22 +00:00
Eric Fiselier 8ed97272ab [coroutines] Fix application of NRVO to Coroutine "Gro" or return object.
Summary:
Fix NRVO for Gro variable.

Previously, we only marked the GRO declaration as an NRVO variable
when its QualType and the function return's QualType matched exactly
(using operator==). However, this was incorrect for two reasons:

1. We were marking non-class types, such as ints, as being NRVO variables.

2. We failed to  handle cases where the canonical types were the same, but the actual `QualType` objects were different. For example, if  one was represented by a typedef. (Example: https://godbolt.org/g/3UFgsL)

This patch fixes these bugs by marking the Gro variable as supporting NRVO only
when `BuildReturnStmt` marks the Gro variable as a coroutine candidate.






Reviewers: rsmith, GorNishanov, nicholas

Reviewed By: GorNishanov

Subscribers: majnemer, cfe-commits

Differential Revision: https://reviews.llvm.org/D42343

llvm-svn: 324037
2018-02-01 23:47:54 +00:00
Eric Fiselier 96f8c5c420 Revert "[coroutines] Fix application of NRVO to Coroutine "Gro" or return object."
This reverts commit r323712. It's causing some test failures on certain machines.
Not sure why, will investigate.

llvm-svn: 323717
2018-01-30 00:32:25 +00:00
Eric Fiselier a8fc370d51 [coroutines] Fix application of NRVO to Coroutine "Gro" or return object.
Summary:
Fix NRVO for Gro variable.

Previously, we only marked the GRO declaration as an NRVO variable
when its QualType and the function return's QualType matched exactly
(using operator==). However, this was incorrect for two reasons:

1. We were marking non-class types, such as ints, as being NRVO variables.

2. We failed to  handle cases where the canonical types were the same, but the actual `QualType` objects were different. For example, if  one was represented by a typedef. (Example: https://godbolt.org/g/3UFgsL)

This patch fixes these bugs by marking the Gro variable as supporting NRVO only
when `BuildReturnStmt` marks the Gro variable as a coroutine candidate.






Reviewers: rsmith, GorNishanov, nicholas

Reviewed By: GorNishanov

Subscribers: majnemer, cfe-commits

Differential Revision: https://reviews.llvm.org/D42343

llvm-svn: 323712
2018-01-29 23:52:57 +00:00
Brian Gesiak 61f4ac98e0 [coroutines] Pass coro func args to promise ctor
Summary:
Use corutine function arguments to initialize a promise type, but only
if the promise type defines a constructor that takes those arguments.
Otherwise, fall back to the default constructor.

Test Plan: check-clang

Reviewers: rsmith, GorNishanov, eric_niebler

Reviewed By: GorNishanov

Subscribers: toby-allsopp, lewissbaker, EricWF, cfe-commits

Differential Revision: https://reviews.llvm.org/D41820

llvm-svn: 323381
2018-01-24 22:15:42 +00:00
Gor Nishanov 04491bd8f3 [coroutines] Promote cleanup.dest.slot allocas to registers to avoid storing it in the coroutine frame
Summary:
We don't want to store cleanup dest slot saved into the coroutine frame (as some of the cleanup code may
access them after coroutine frame destroyed).

This is an alternative to https://reviews.llvm.org/D37093

It is possible to do this for all functions, but, cursory check showed that in -O0, we get slightly longer function (by 1-3 instructions), thus, we are only limiting cleanup.dest.slot elimination to coroutines.

Reviewers: rjmccall, hfinkel, eric_niebler

Reviewed By: eric_niebler

Subscribers: EricWF, cfe-commits

Differential Revision: https://reviews.llvm.org/D39768

llvm-svn: 317981
2017-11-11 17:00:43 +00:00
Gor Nishanov 0f33300609 [coroutines] Support coroutine-handle returning await-suspend (i.e symmetric control transfer)
Summary:
If await_suspend returns a coroutine_handle, as in the example below:
```
  coroutine_handle<> await_suspend(coroutine_handle<> h) {
    coro.promise().waiter = h;
    return coro;
  }
```
suspensionExpression processing will resume the coroutine pointed at by that handle.
Related LLVM change rL311751 makes resume calls of this kind `musttail` at any optimization level.

This enables unlimited symmetric control transfer from coroutine to coroutine without blowing up the stack.

Reviewers: GorNishanov

Reviewed By: GorNishanov

Subscribers: rsmith, EricWF, cfe-commits

Differential Revision: https://reviews.llvm.org/D37131

llvm-svn: 311762
2017-08-25 04:46:54 +00:00
Eric Fiselier e9a5e7e407 [coroutines] Evaluate the operand of void `co_return` expressions.
Summary:
Previously Clang incorrectly ignored the expression of a void `co_return`. This patch addresses that bug.

I'm not quite sure if I got the code-gen right, but this patch is at least a start.

Reviewers: rsmith, GorNishanov

Reviewed By: rsmith, GorNishanov

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D36070

llvm-svn: 309545
2017-07-31 07:48:13 +00:00
Eric Fiselier cddaf8728f [coroutines] Allow co_await and co_yield expressions that return an lvalue to compile
Summary:
The title says it all.


Reviewers: GorNishanov, rsmith

Reviewed By: GorNishanov

Subscribers: rjmccall, cfe-commits

Differential Revision: https://reviews.llvm.org/D34194

llvm-svn: 305496
2017-06-15 19:43:36 +00:00
Eric Fiselier de7943b947 [coroutines] Fix rebuilding of dependent coroutine parameters
Summary:
We were not handling correctly rebuilding of parameter and were not creating copies for them.
Now we will always rebuild parameter moves in TreeTransform's TransformCoroutineBodyStmt.

Reviewers: rsmith, GorNishanov

Reviewed By: rsmith

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D33797

llvm-svn: 304620
2017-06-03 00:22:18 +00:00
Gor Nishanov 050e79e958 CGCleanup: (NFC) add another test for r304335 - Don't try to spill static allocas
Summary:
Coroutine related test that used to trigger broken IR prior to r304335.

```
%x = alloca i32, align 4
store i32* %x, i32** %tmp.exprcleanup, align 4 ; <===== HERE
%ref.tmp3 = alloca %struct.A, align 1
%agg.tmp5 = alloca %"struct.std::experimental::coroutines_v1::coroutine_handle.0", align 4
%tmp.exprcleanup = alloca i32*, align 4
%allocapt = bitcast i32 undef to i32
store i32 %0, i32* %.addr, align 4
```

Fixed with r304335

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D33750

llvm-svn: 304380
2017-06-01 01:15:25 +00:00
Gor Nishanov 33d5fd24a0 [coroutines] Add support for coroutines with non-scalar parameters
Summary:
Simple types like int are handled by LLVM Coroutines just fine.
But for non-scalar parameters we need to create copies of those parameters in the coroutine frame and make all uses of those parameters to refer to parameter copies.

Reviewers: rsmith, EricWF, GorNishanov

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D33507

llvm-svn: 303803
2017-05-24 20:09:14 +00:00
Gor Nishanov afff89eecb [coroutines] Make generic lambda coroutines work
Summary:
1. Coroutine cannot be constexpr (added a check in SemaLambda.cpp not to mark coroutine as constexpr)
2. TransformCoroutineBodyStmt should transform ResultDecl and ReturnStmt

Reviewers: rsmith, GorNishanov

Reviewed By: GorNishanov

Subscribers: EricWF, cfe-commits

Differential Revision: https://reviews.llvm.org/D33498

llvm-svn: 303764
2017-05-24 15:44:57 +00:00
Gor Nishanov ab7e8aebee [coroutines] [NFC] Add tests for return_void, unhandled_exception and promise dtor
Summary:
* Test that coroutine promise destructor is called.
* Test that we call return_void on fallthrough
* Test that we call unhandled exception in a try catch surrounding the body

Reviewers: EricWF, GorNishanov

Reviewed By: GorNishanov

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D33479

llvm-svn: 303748
2017-05-24 14:19:48 +00:00
Gor Nishanov 4c2f68fd7c [coroutines] Implement correct GRO lifetime
Summary:
Sema creates a declaration for gro variable as:

auto $gro = $promise.get_return_object();

However, gro variable has to outlive coroutine frame and coroutine promise, but,
it can only be initialized after the coroutine promise was created, thus, we
split its emission in two parts: EmitGroAlloca emits an alloca and sets up
the cleanups. Later when the coroutine promise is available we initialize
the gro and set the flag that the cleanup is now active.

Duplicate of: https://reviews.llvm.org/D31670 (which arc patch refuses to apply for some reason)

Reviewers: GorNishanov, rsmith

Reviewed By: GorNishanov

Subscribers: EricWF, cfe-commits

Differential Revision: https://reviews.llvm.org/D33477

llvm-svn: 303716
2017-05-24 02:38:26 +00:00
Gor Nishanov e4f15a2bf0 [coroutines] Skip over passthrough operator co_await
https://reviews.llvm.org/D31627

llvm-svn: 303605
2017-05-23 05:25:31 +00:00