Implements https://isocpp.org/files/papers/P2662R3.pdf
The feature is exposed as an extension in older language modes.
Mangling is not yet supported and that is something we will have to do before release.
C++14 introduced deduced return type for regular functions, but shortly after [CWG1878](https://wg21.link/cwg1878) was filed and resolved to disallow deduced return types in conversion function templates. So this patch diagnoses such usage of deduced return type in C++14 mode onwards.
Fixes#51776
This patch replaces the `__arm_new_za`, `__arm_shared_za` and
`__arm_preserves_za` attributes in favour of:
* `__arm_new("za")`
* `__arm_in("za")`
* `__arm_out("za")`
* `__arm_inout("za")`
* `__arm_preserves("za")`
As described in https://github.com/ARM-software/acle/pull/276.
One change is that `__arm_in/out/inout/preserves(S)` are all mutually
exclusive, whereas previously it was fine to write `__arm_shared_za
__arm_preserves_za`. This case is now represented with `__arm_in("za")`.
The current implementation uses the same LLVM attributes under the hood,
since `__arm_in/out/inout` are all variations of "shared ZA", so can use
the existing `aarch64_pstate_za_shared` attribute in LLVM.
#77941 will add support for the new "zt0" state as introduced
with SME2.
Per [[class.friend]p6](http://eel.is/c++draft/class.friend#6) a friend
function shall not be defined if its name isn't unqualified. A
_template-id_ is not a name, meaning that a friend function
specialization does not meet this criteria and cannot be defined.
GCC, MSVC, and EDG all consider friend function specialization
definitions to be invalid de facto explicit specializations and diagnose
them as such.
Instantiating a dependent friend function specialization definition
[currently sets off an assert](https://godbolt.org/z/Krqdq95hY) in
`FunctionDecl::setFunctionTemplateSpecialization`. This happens because
we do not set the `TemplateSpecializationKind` of the `FunctionDecl`
created by template argument deduction to `TSK_ExplicitSpecialization`
for friend functions
[here](https://github.com/llvm/llvm-project/blob/main/clang/lib/Sema/SemaTemplate.cpp#L9600).
I changed the assert condition because I believe this is the correct
behavior.
If a template is defined via an external AST source, it won't have a
location. When we emit warnings about misusing such templates we
shouldn't emit a "template is declared here" warning with no location,
as that's just confusing.
Reviewers: llvm-beanz, erichkeane, AaronBallman
Reviewed By: erichkeane, AaronBallman
Pull Request: https://github.com/llvm/llvm-project/pull/71264
Close https://github.com/llvm/llvm-project/issues/73893
As the issue shows, generally, the diagnose information for
invisible namespace is confusing more than helpful. Also this patch
implements the same solution as suggested in the issue: don't diagnose
on invisible namespace.
- Support non-member functions and callable objects for size and data().
We previously tried to (badly) pick the best overload ourselves, in a
way that would only support member functions. We now leave clang
construct an unresolved member expression and call that, properly
performing overload resolution with callable objects and static
functions, consistent with the logic for `get` calls for structured
bindings.
- Support UDLs as message expression.
- Add tests and mark CWG2798 as resolved
Close https://github.com/llvm/llvm-project/issues/71347
Previously I misread the concept of module purview. I thought if a
declaration attached to a unnamed module, it can't be part of the module
purview. But after the issue report, I recognized that module purview is
more of a concept about locations instead of semantics.
Concretely, the things in the language linkage after module declarations
can be exported.
This patch refactors `Module::isModulePurview()` and introduces some
possible code cleanups.
This patch converts `CXXConstructExpr::ConstructionKind` into a scoped enum in namespace scope, making it eligible for forward declaring. This is useful in cases like annotating bit-fields with `preferred_type`.
During the recent refactoring (b120fe8d3288c4dca1b5427ca34839ce8833f71c) this enum was moved out of `RecordDecl`. During post-commit review it was found out that its association with `RecordDecl` should be expressed in the name.
This patch converts `LinkageSpecDecl::LanguageIDs` into scoped enum, and moves it to namespace scope, so that it can be forward-declared where required.
This patch moves ElaboratedTypeKeyword before `Type` definition so that the enum is complete where bit-field for it is declared. It also converts it to scoped enum and removes `ETK_` prefix.
Per https://eel.is/c++draft/dcl.fct.def.default#2.2, the explicit object
parameter of a defaulted special member function must be of the same
type as the one of an equivalent implicitly defaulted function, ignoring
references.
Fixes#69233
The dependence of a template argument is not only determined by the
argument itself, but also by the type of the template parameter:
> Furthermore, a non-type
[template-argument](https://eel.is/c++draft/temp.names#nt:template-argument)
is dependent if the corresponding non-type
[template-parameter](https://eel.is/c++draft/temp.param#nt:template-parameter)
is of reference or pointer type and the
[template-argument](https://eel.is/c++draft/temp.names#nt:template-argument)
designates or points to a member of the current instantiation or a
member of a dependent
type[.](https://eel.is/c++draft/temp.dep#temp-3.sentence-1)
For example:
```cpp
struct A{};
template <const A& T>
const A JoinStringViews = T;
template <int V>
class Builder {
public:
static constexpr A Equal{};
static constexpr auto Val = JoinStringViews<Equal>;
};
```
The constant expression `Equal` is not dependent, but because the type
of the template parameter is a reference type and `Equal` is a member of
the current instantiation, the template argument of
`JoinStringViews<Equal>` is actually dependent, which makes
`JoinStringViews<Equal>` dependent.
When a template-id of a variable template is dependent,
`CheckVarTemplateId` will return an `UnresolvedLookupExpr`, but
`UnresolvedLookupExpr` calculates dependence by template arguments only
(the `ConstantExpr` `Equal` here), which is not dependent. This causes
type deduction to think that `JoinStringViews<Equal>` is `OverloadTy`
and treat it as a function template, which is clearly wrong.
This PR adds a `KnownDependent` parameter to the constructor of
`UnresolvedLookupExpr`. After canonicalization, if `CanonicalConverted`
contains any dependent argument, `KnownDependent` is set to `true`. This
fixes the dependence calculation of `UnresolvedLookupExpr` for dependent
variable templates.
Fixes#65153 .
This patch fixes the display of characters appearing in LHS or RHS of == expression in notes to static assertion failure.
This applies C-style escape if the printed character is a special character. This also adds a numerical value displayed next to the character representation.
This also tries to print multi-byte characters if the user-provided expression is multi-byte char type.
Reviewed By: cor3ntin
Differential Revision: https://reviews.llvm.org/D155610
CheckDefaultArgumentVisitor::Visit(...) assumes that the children of
Expr will not be NULL. This is not a valid assumption and when we have a
CXXFoldExpr the children can be NULL and this causes a crash.
Fixes: https://github.com/llvm/llvm-project/issues/67395
This reverts commit 491b2810fb7fe5f080fa9c4f5945ed0a6909dc92.
This change broke valid code and generated incorrect diagnostics, see
https://reviews.llvm.org/D155064
This patch makes clang diagnose extensive cases of consteval if and is_constant_evaluated usage that are tautologically true or false.
This introduces a new IsRuntimeEvaluated boolean flag to Sema::ExpressionEvaluationContextRecord that means the immediate appearance of if consteval or is_constant_evaluated are tautologically false(e.g. inside if !consteval {} block or non-constexpr-qualified function definition body)
This patch also pushes new expression evaluation context when parsing the condition of if constexpr and initializer of constexpr variables so that Sema can be aware that the use of consteval if and is_consteval are tautologically true in if constexpr condition and constexpr variable initializers.
BEFORE this patch, the warning for is_constant_evaluated was emitted from constant evaluator. This patch moves the warning logic to Sema in order to diagnose tautological use of is_constant_evaluated in the same way as consteval if.
This patch separates initializer evaluation context from InitializerScopeRAII.
This fixes a bug that was happening when user takes address of function address in initializers of non-local variables.
Fixes https://github.com/llvm/llvm-project/issues/43760
Fixes https://github.com/llvm/llvm-project/issues/51567
Reviewed By: cor3ntin, ldionne
Differential Revision: https://reviews.llvm.org/D155064
The compiler should not warn on code such as:
class [[maybe_unused]] MaybeUnusedClass {};
class C {
MaybeUnusedClass c;
};
Patch based on comments on the bug by Shafik and Aaron.
Fixes#61334
Differential revision: https://reviews.llvm.org/D159083
This makes sure we can preserve invalid-ness for consumers of this
node, it prevents crashes. It also aligns better with rest of the places that
store invalid expressions.
Differential Revision: https://reviews.llvm.org/D157868
This patch adds all the language-level function keywords defined in:
https://github.com/ARM-software/acle/pull/188 (merged)
https://github.com/ARM-software/acle/pull/261 (update after D148700 landed)
The keywords are used to control PSTATE.ZA and PSTATE.SM, which are
respectively used for enabling the use of the ZA matrix array and Streaming
mode. This information needs to be available on call sites, since the use
of ZA or streaming mode may have to be enabled or disabled around the
call-site (depending on the IR attributes set on the caller and the
callee). For calls to functions from a function pointer, there is no IR
declaration available, so the IR attributes must be added explicitly to the
call-site.
With the exception of '__arm_locally_streaming' and '__arm_new_za' the
information is part of the function's interface, not just the function
definition, and thus needs to be propagated through the
FunctionProtoType::ExtProtoInfo.
This patch adds the defintions of these keywords, as well as codegen and
semantic analysis to ensure conversions between function pointers are valid
and that no conflicting keywords are set. For example, '__arm_streaming'
and '__arm_streaming_compatible' are mutually exclusive.
Differential Revision: https://reviews.llvm.org/D127762
This reverts commit bddaa35177861545fc329123e55b6a3b34549507.
Reverting as requested at https://reviews.llvm.org/D155895#4566945
(for breaking tests on Windows).
Anonymous unions should be transparent wrt `[[clang::trivial_abi]]`.
Consider the test input below:
```
struct [[clang::trivial_abi]] Trivial {
Trivial() {}
Trivial(Trivial&& other) {}
Trivial& operator=(Trivial&& other) { return *this; }
~Trivial() {}
};
static_assert(__is_trivially_relocatable(Trivial), "");
struct [[clang::trivial_abi]] S2 {
S2(S2&& other) {}
S2& operator=(S2&& other) { return *this; }
~S2() {}
union { Trivial field; };
};
static_assert(__is_trivially_relocatable(S2), "");
```
Before the fix Clang would warn that 'trivial_abi' is disallowed on 'S2'
because it has a field of a non-trivial class type (the type of the
anonymous union is non-trivial, because it doesn't have the
`[[clang::trivial_abi]]` attribute applied to it). Consequently, before
the fix the `static_assert` about `__is_trivially_relocatable` would
fail.
Note that `[[clang::trivial_abi]]` cannot be applied to the anonymous
union, because Clang warns that 'trivial_abi' is disallowed on '(unnamed
union at ...)' because its copy constructors and move constructors are
all deleted. Also note that it is impossible to provide copy nor move
constructors for anonymous unions and structs.
Reviewed By: gribozavr2
Differential Revision: https://reviews.llvm.org/D155895
This is a C++ feature that allows the use of `_` to
declare multiple variable of that name in the same scope;
these variables can then not be referred to.
In addition, while P2169 does not extend to parameter
declarations, we stop warning on unused parameters of that name,
for consistency.
The feature is backported to all C++ language modes.
Reviewed By: #clang-language-wg, aaron.ballman
Differential Revision: https://reviews.llvm.org/D153536
This patch does a few things:
* Fix aggregate initialization.
When an aggregate has an initializer that is immediate-escalating,
the context in which it is used automatically becomes an immediate function.
The wording does that by rpretending an aggregate initialization is itself
an invocation which is not really how clang works, so my previous attempt
was... wrong.
* Fix initialization of defaulted constructors with immediate escalating
default member initializers.
The wording was silent about that case and I did not handled it fully
https://cplusplus.github.io/CWG/issues/2760.html
* Fix diagnostics
In some cases clang would produce additional and unhelpful
diagnostics by listing the invalid references to consteval
function that appear in immediate escalating functions
Fixes https://github.com/llvm/llvm-project/issues/63742
Reviewed By: aaron.ballman, #clang-language-wg, Fznamznon
Differential Revision: https://reviews.llvm.org/D155175
https://godbolt.org/z/cMKE3o1aG
According to the issue https://github.com/llvm/llvm-project/issues/63960 , compiler falsely complains that no viable `operator<=>` was found while we are actually looking for a `operator==`.
This bug has been fixed through adding a check of the `OverloadedOperatorKind` type's object, `OO`, to see if it is `OO_EqualEqual` in addition to `OO_ExclaimEqual`.
Reviewed By: #clang-language-wg, cor3ntin
Differential Revision: https://reviews.llvm.org/D155714
1. Teach -Wuser-defined-literals to warn on using double underscores in
literal suffix identifiers.
2. Add -Wdeprecated-literal-operator to warn about the use of the first
grammar production of literal-operator-id, which defaults to off for now.
Differential Revision: https://reviews.llvm.org/D152632
This patch renames the `OpenMPIRBuilderConfig` flags to reduce confusion over
their meaning. `IsTargetCodegen` becomes `IsGPU`, whereas `IsEmbedded` becomes
`IsTargetDevice`. The `-fopenmp-is-device` compiler option is also renamed to
`-fopenmp-is-target-device` and the `omp.is_device` MLIR attribute is renamed
to `omp.is_target_device`. Getters and setters of all these renamed properties
are also updated accordingly. Many unit tests have been updated to use the new
names, but an alias for the `-fopenmp-is-device` option is created so that
external programs do not stop working after the name change.
`IsGPU` is set when the target triple is AMDGCN or NVIDIA PTX, and it is only
valid if `IsTargetDevice` is specified as well. `IsTargetDevice` is set by the
`-fopenmp-is-target-device` compiler frontend option, which is only added to
the OpenMP device invocation for offloading-enabled programs.
Differential Revision: https://reviews.llvm.org/D154591
This patch proposes to handle in an uniform fashion
the parsing of strings that are never evaluated,
in asm statement, static assert, attrributes, extern,
etc.
Unevaluated strings are UTF-8 internally and so currently
behave as narrow strings, but these things will diverge with
D93031.
The big question both for this patch and the P2361 paper
is whether we risk breaking code by disallowing
encoding prefixes in this context.
I hope this patch may allow to gather some data on that.
Future work:
Improve the rendering of unicode characters, line break
and so forth in static-assert messages
Reviewed By: aaron.ballman, shafik
Differential Revision: https://reviews.llvm.org/D105759
This commit implements support for WebAssembly table types and
respective builtins. Table tables are WebAssembly objects to store
reference types. They have a large amount of semantic restrictions
including, but not limited to, only being allowed to be declared
at the top-level as static arrays of zero-length. Not being arguments
or result of functions, not being stored ot memory, etc.
This commit introduces the __attribute__((wasm_table)) to attach to
arrays of WebAssembly reference types. And the following builtins to
manage tables:
* ref __builtin_wasm_table_get(table, idx)
* void __builtin_wasm_table_set(table, idx, ref)
* uint __builtin_wasm_table_size(table)
* uint __builtin_wasm_table_grow(table, ref, uint)
* void __builtin_wasm_table_fill(table, idx, ref, uint)
* void __builtin_wasm_table_copy(table, table, uint, uint, uint)
This commit also enables reference-types feature at bleeding-edge.
This is joint work with Alex Bradbury (@asb).
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D139010
The C++ standard allows abstract parameters in deleted functions
and in function declarations
> The type of a parameter or the return type for a function definition
> shall not be a (possibly cv-qualified) class type that is
> incomplete or abstract within the function body
> unless the function is deleted.
Fixes https://github.com/llvm/llvm-project/issues/63012
Reviewed By: #clang-language-wg, aaron.ballman
Differential Revision: https://reviews.llvm.org/D152096
