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
Define the __vector_pair and __vector_quad types that are used to manipulate
the new accumulator registers introduced by MMA on PowerPC. Because these two
types are specific to PowerPC, they are defined in a separate new file so it
will be easier to add other PowerPC specific types if we need to in the future.
Differential Revision: https://reviews.llvm.org/D81508
Because of typo-correction, the AST can be transformed, and the transformed
AST is marginally useful for diagnostics purpose, the following
diagnostics usually do harm than good (easily cause confusions).
Given the following code:
```
void abcc();
void test() {
if (abc());
// diagnostic 1 (for the typo-correction): the typo is correct to `abcc()`, so the code is treate as `if (abcc())` in AST perspective;
// diagnostic 2 (for mismatch type): we perform an type-analysis on `if`, discover the type is not match
}
```
The secondary diagnostic "convertable to bool" is likely bogus to users.
The idea is to use RecoveryExpr (clang's dependent mechanism) to preserve the
recovery behavior but suppress all follow-up diagnostics.
Differential Revision: https://reviews.llvm.org/D89946
This allows using annotation in a much more contexts than it currently has.
especially when annotation with template or constexpr.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D88645
The dependent mechanism for C error-recovery is mostly finished,
this is the only place we have missed.
Differential Revision: https://reviews.llvm.org/D89045
This reapplies D88384 with the minor modification that an assertion was
changed to a regular conditional and graceful exit from
ASTContext::mergeTypes.
This test is going to be removed because using dynamic rounding mode
in initializers is changing. It also causes build failures in some
cases, so remove it now.
- Fix a memory leak accidentally introduced yesterday by using CodeGen's
existing mangling context instead of creating a new context afresh.
- Move GNU-runtime ObjC method mangling into the AST mangler; this will
eventually be necessary to support direct methods there, but is also
just the right architecture.
- Make the Apple-runtime method mangling work properly when given an
interface declaration, fixing a bug (which had solidified into a test)
where mangling a category method from the interface could cause it to
be mangled as if the category name was a class name. (Category names
are namespaced within their class and have no global meaning.)
- Fix a code cross-reference in dsymutil.
Based on a patch by Ellis Hoag.
Especially for templates we need to check at some point if the base
function matches the specialization we might call instead. Before this
lead to the replacement of `std::sqrt(int(2))` calls with one that
converts the argument to a `std::complex<int>`, clearly not the desired
behavior.
Reported as PR47655
Reviewed By: JonChesterfield
Differential Revision: https://reviews.llvm.org/D88384
The change implements evaluation of constant floating point expressions
under non-default rounding modes. The main objective was to support
evaluation of global variable initializers, where constant rounding mode
may be specified by `#pragma STDC FENV_ROUND`.
Differential Revision: https://reviews.llvm.org/D87822
This attribute allows declarations to be restricted to the framework
itself, enabling Swift to remove the declarations when importing
libraries. This is useful in the case that the functions can be
implemented in a more natural way for Swift.
This is based on the work of the original changes in
8afaf3aad2
Differential Revision: https://reviews.llvm.org/D87720
Reviewed By: Aaron Ballman
Add the `swift_newtype` attribute which allows a type definition to be
imported into Swift as a new type. The imported type must be either an
enumerated type (enum) or an object type (struct).
This is based on the work of the original changes in
8afaf3aad2
Differential Revision: https://reviews.llvm.org/D87652
Reviewed By: Aaron Ballman
Previously methods `FPOptions::get*` returned unsigned value even if the
corresponding property was represented by specific enumeration type. With
this change such methods return actual type of the property. It also
allows printing value of a property as text rather than integer code.
Differential Revision: https://reviews.llvm.org/D87812
Instead of relying on whether a certain identifier is a builtin, introduce BuiltinAttr to specify a declaration as having builtin semantics.
This fixes incompatible redeclarations of builtins, as reverting the identifier as being builtin due to one incompatible redeclaration would have broken rest of the builtin calls.
Mostly-compatible redeclarations of builtins also no longer have builtin semantics. They don't call the builtin nor inherit their attributes.
A long-standing FIXME regarding builtins inside a namespace enclosed in extern "C" not being recognized is also addressed.
Due to the more correct handling attributes for builtin functions are added in more places, resulting in more useful warnings.
Tests are updated to reflect that.
Intrinsics without an inline definition in intrin.h had `inline` and `static` removed as they had no effect and caused them to no longer be recognized as builtins otherwise.
A pthread_create() related test is XFAIL-ed, as it relied on it being recognized as a builtin based on its name.
The builtin declaration syntax is too restrictive and doesn't allow custom structs, function pointers, etc.
It seems to be the only case and fixing this would require reworking the current builtin syntax, so this seems acceptable.
Fixes PR45410.
Reviewed By: rsmith, yutsumi
Differential Revision: https://reviews.llvm.org/D77491
With this extension the effects of `omp begin declare variant` will be
applied to template function declarations. The behavior is opt-in and
controlled by the `extension(allow_templates)` trait. While generally
useful, this will enable us to implement complex math function calls by
overloading the templates of the standard library with the ones in
libc++.
Reviewed By: JonChesterfield
Differential Revision: https://reviews.llvm.org/D85735
This extension allows to declare variants in between `omp begin/end
declare variant` that do not match the type of the existing function
with that name. Without this extension we would not find a base function
(with a compatible type), therefore create a new one, which would
cause conflicting declarations. With this extension we will not create
"missing" base functions, which basically renders these specializations
harmless. They will be generated but never called.
Reviewed By: JonChesterfield
Differential Revision: https://reviews.llvm.org/D85878
Due to `omp begin/end declare variant`, OpenMP context selectors can be
nested. This patch adds initial support for this so we can use it for
target math variants. We should improve the detection of "equivalent"
scores and user conditions, we should also revisit the data structures
of the OMPTraitInfo object, however, both are not pressing issues right
now.
Reviewed By: JonChesterfield
Differential Revision: https://reviews.llvm.org/D85877
This extends semantic analysis of attributes for Swift interoperability
by introducing the `swift_bridge` attribute. This attribute enables
bridging Objective-C types to Swift specific types.
This is based on the work of the original changes in
8afaf3aad2
Differential Revision: https://reviews.llvm.org/D87532
Reviewed By: Aaron Ballman
Extend the semantic attributes that clang processes for Swift to include
`swift_bridged_typedef`. This attribute enables typedefs to be bridged
into Swift with a bridged name.
This is based on the work of the original changes in
8afaf3aad2
Differential Revision: https://reviews.llvm.org/D87396
Reviewed By: Aaron Ballman
This is recommit of 6c8041aa0f, reverted in de044f7562 because of some
fails. Original commit message is below.
This change allow a CastExpr to have optional FPOptionsOverride object,
stored in trailing storage. Of all cast nodes only ImplicitCastExpr,
CStyleCastExpr, CXXFunctionalCastExpr and CXXStaticCastExpr are allowed
to have FPOptions.
Differential Revision: https://reviews.llvm.org/D85960
This change allow a CastExpr to have optional FPOptionsOverride object,
stored in trailing storage. Of all cast nodes only ImplicitCastExpr,
CStyleCastExpr, CXXFunctionalCastExpr and CXXStaticCastExpr are allowed
to have FPOptions.
Differential Revision: https://reviews.llvm.org/D85960
Decl::dump is primarily used for debugging to visualise the current state of a
declaration. Usually Decl::dump just displays the current state of the Decl and
doesn't actually change any of its state, however since commit
457226e02a the method actually started loading
additional declarations from the ExternalASTSource. This causes that calling
Decl::dump during a debugging session now actually does permanent changes to the
AST and will cause the debugged program run to deviate from the original run.
The change that caused this behaviour is the addition of
`hasConstexprDestructor` (which is called from the TextNodeDumper) which
performs a lookup into the current CXXRecordDecl to find the destructor. All
other similar methods just return their respective bit in the DefinitionData
(which obviously doesn't have such side effects).
This just changes the node printer to emit "unknown_constexpr" in case a
CXXRecordDecl is dumped that could potentially call into the ExternalASTSource
instead of the usually empty string/"constexpr". For CXXRecordDecls that can
safely be dumped the old behaviour is preserved
Reviewed By: bruno
Differential Revision: https://reviews.llvm.org/D80878
This change implements pragma STDC FENV_ROUND, which is introduced by
the extension to standard (TS 18661-1). The pragma is implemented only
in frontend, it sets apprpriate state of FPOptions stored in Sema. Use
of these bits in constant evaluation adn/or code generator is not in the
scope of this change.
Parser issues warning on unsuppored pragma when it encounteres pragma
STDC FENV_ROUND, however it makes syntax checks and updates Sema state
as if the pragma were supported.
Primary purpose of the partial implementation is to facilitate
development of non-default floating poin environment. Previously a
developer cannot set non-default rounding mode in sources, this mades
preparing tests for say constant evaluation substantially complicated.
Differential Revision: https://reviews.llvm.org/D86921
OpenMP 5.0 supports nested declare target regions. So, in general,it is
allow to mark a declarationas declare target with different device_type
or link type. Patch adds support for such kind of nesting.
Differential Revision: https://reviews.llvm.org/D86239
ns_error_domain can be used by, e.g. NS_ERROR_ENUM, in order to
identify a global declaration representing the domain constant.
Introduces the attribute, Sema handling, diagnostics, and test case.
This is cherry-picked from a14779f504
and adapted to updated Clang APIs.
Reviewed By: gribozavr2, aaron.ballman
Differential Revision: https://reviews.llvm.org/D84005
The CXXFoldExpr's range is invalid if the cxxfoldexpr is formed via the
Concept's TypeContraints (because the parentheses are not written in the
source code). We fallback to use the range from the pattern.
Differential Revision: https://reviews.llvm.org/D85645
Summary:
Introduced OMPChildren class to handle all associated clauses, statement
and child expressions/statements. It allows to represent some directives
more correctly (like flush, depobj etc. with pseudo clauses, ordered
depend directives, which are standalone, and target data directives).
Also, it will make easier to avoid using of CapturedStmt in directives,
if required (atomic, tile etc. directives).
Also, it simplifies serialization/deserialization of the
executable/declarative directives.
Reduces number of allocation operations for mapper declarations.
Reviewers: jdoerfert
Subscribers: yaxunl, guansong, jfb, cfe-commits, sstefan1, aaron.ballman, caomhin
Tags: #clang
Differential Revision: https://reviews.llvm.org/D83261
This patch introduces 2 new address spaces in OpenCL: global_device and global_host
which are a subset of a global address space, so the address space scheme will be
looking like:
```
generic->global->host
->device
->private
->local
constant
```
Justification: USM allocations may be associated with both host and device memory. We
want to give users a way to tell the compiler the allocation type of a USM pointer for
optimization purposes. (Link to the Unified Shared Memory extension:
https://github.com/intel/llvm/blob/sycl/sycl/doc/extensions/USM/cl_intel_unified_shared_memory.asciidoc)
Before this patch USM pointer could be only in opencl_global
address space, hence a device backend can't tell if a particular pointer
points to host or device memory. On FPGAs at least we can generate more
efficient hardware code if the user tells us where the pointer can point -
being able to distinguish between these types of pointers at compile time
allows us to instantiate simpler load-store units to perform memory
transactions.
Patch by Dmitry Sidorov.
Reviewed By: Anastasia
Differential Revision: https://reviews.llvm.org/D82174
Summary:
It returned an invalid location in case of a constrained-parameter
with no explicit arguments.
Reviewers: hokein
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D84613
Xun Li