i.e., in a call like `function(new Unknown);` the parser should skip only until the
semicolon.
Before this change, everything was skipped until a balanced closing
parenthesis or brace was found. This strategy can cause completely bogus
ASTs. For instance, in the case of the test `new-unknown-type.cpp`,
`struct Bar` would end nested under the namespace `a::b`.
OpenCL has a reserved operator (^^), the use of which was diagnosed as
an error (735c6cdebdcd4292928079cb18a90f0dd5cd65fb). However, OpenCL
also encourages working with the blocks language extension. This token
has a parsing ambiguity as a result. Consider:
unsigned x=0;
unsigned y=x^^{return 0;}();
This should result in y holding the value zero (0^0) through an
immediately invoked block call as the right-hand side of the xor
operator. However, it causes errors instead because of this reserved
token: https://godbolt.org/z/navf7jTv1
This token is still reserved in OpenCL 3.0, so we still wish to issue a
diagnostic for its use. However, we do not need to create a token for an
extension point that's been unused for about a decade. So this patch
moves the diagnostic from a parsing diagnostic to a lexing diagnostic
and no longer forms a single token. The diagnostic behavior is slightly
worse as a result, but still seems acceptable.
Part of the reason this is coming up is because WG21 is considering
using ^^ as a token for reflection, so this token may come back in the
future.
When various `Sema*.h` and `Sema*.cpp` files were created, cleanup of
`Sema.h` includes and forward declarations was left for the later.
Now's the time. This commit touches `Sema.h` and Sema components:
1. Unused includes are removed.
2. Unused forward declarations are removed.
3. Missing includes are added (those files are largely IWYU-clean now).
4. Includes were converted into forward declarations where possible.
As this commit focuses on headers, all changes to `.cpp` files were
minimal, and were aiming at keeping everything buildable.
HLSL has a set of intangible types which are described in in the
[draft HLSL Specification
(**[Basic.types]**)](https://microsoft.github.io/hlsl-specs/specs/hlsl.pdf):
There are special implementation-defined types such as handle types,
which fall into a category of standard intangible types. Intangible
types are types that have no defined object representation or value
representation, as such the size is unknown at compile time.
A class type T is an intangible class type if it contains an base
classes or members of intangible class type, standard intangible type,
or arrays of such types. Standard intangible types and intangible class
types are collectively called intangible
types([9](https://microsoft.github.io/hlsl-specs/specs/hlsl.html#Intangible)).
This PR implements one standard intangible type `__hlsl_resource_t`
and sets up the infrastructure that will make it easier to add more
in the future, such as samplers or raytracing payload handles. The
HLSL intangible types are declared in
`clang/include/clang/Basic/HLSLIntangibleTypes.def` and this file is
included with related macro definition in most places that require edits
when a new type is added.
The new types are added as keywords and not typedefs to make sure they
cannot be redeclared, and they can only be declared in builtin implicit
headers. The `__hlsl_resource_t` type represents a handle to a memory
resource and it is going to be used in builtin HLSL buffer types like this:
template <typename T>
class RWBuffer {
[[hlsl::contained_type(T)]]
[[hlsl::is_rov(false)]]
[[hlsl::resource_class(uav)]]
__hlsl_resource_t Handle;
};
Part 1/3 of llvm/llvm-project#90631.
---------
Co-authored-by: Justin Bogner <mail@justinbogner.com>
`is_null_pointer` can be implemented very efficiently as
`__is_same(__remove_cv(T), decltype(nullptr))`. Since GCC supports both
of these builtins as well, libc++ has no interest in using
`__is_nullptr` instead. Furthermore, I could find only a single use in
the wild
(https://sourcegraph.com/search?q=context:global+__is_nullptr%28+-file:clang&patternType=keyword&sm=0).
Because of these reasons I don't think it's worth keeping this builtin
around.
There are 5 unary operators that can be followed by a non-parenthesized
expression: `sizeof`, `__datasizeof`, `__alignof`, `alignof`,
`_Alignof`. When we nest them too deep, `BalancedDelimiterTracker` does
not help, because there are no parentheses, and we crash. Instead, this
patch recognize chains of those operators, and parse them with
sufficient stack space.
Fixes#45061
`__is_layout_compatible` was added in Clang 19 (#81506), and at that
time it wasn't entirely clear whether it should be a revertible type
trait or not. We decided to follow the example of other type traits.
Since then #95969 happened, and now we know that we don't want new
revertible type traits.
This patch removes `__is_layout_compatible` from revertible type traits
list, and leaves a comment what revertible type traits are, and that new
type traits should not be added there.
The intention is to also cherry-pick this to 19 branch.
The builtin computes the discriminator for a type, which can be used to
sign/authenticate function pointers and member function pointers.
If the type passed to the builtin is a C++ member function pointer type,
the result is the discriminator used to signed member function pointers
of that type. If the type is a function, function pointer, or function
reference type, the result is the discriminator used to sign functions
of that type. It is ill-formed to use this builtin with any other type.
A call to this function is an integer constant expression.
Co-Authored-By: John McCall rjmccall@apple.com
It seems for C++ lexer has some caching ability which doesn't expect
injecting "new" tokens in the middle of the cache. Technically #embed
tokens are not completely new since they have already been read from the
file and there was #embed annotation token in this place, so set
`reinject` flag for them to silence assertion.
Instead of playing "whack a mole" with places where #embed should be
expanded as comma-separated list, just inject each byte as a token back
into the stream, separated by commas.
This reverts commit ce4aada6e2135e29839f672a6599db628b53295d and a
follow-up patch 8ef26f1289bf069ccc0d6383f2f4c0116a1206c1.
This new warning can not be fully suppressed by the
`-Wno-missing-dependent-template-keyword` flag, this gives developer no
time to do the cleanup in a large codebase, see https://github.com/llvm/llvm-project/pull/98547#issuecomment-2228250884
Constructs like `__is_pointer(Foo)` are never considered to be functions
declarations.
This matches usages in libstdc++, and we can hope
no one else redefine these reserved identifiers.
Fixes#95598
Reapplies #92957, fixing an instance where the `template` keyword was
missing prior to a dependent name in `llvm/ADT/ArrayRef.h`. An
_alias-declaration_ is used to work around a bug affecting GCC releases
before 11.1 (see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94799) which
rejects the use of the `template` keyword prior to the
_nested-name-specifier_ in the class member access.
CWG1835 was one of the many core issues resolved by P1787R6: "Declarations and where to
find them" (http://wg21.link/p1787r6). Its resolution changes how
member-qualified names (as defined by [basic.lookup.qual.general] p2) are looked
up. This patch implementation that resolution.
Previously, an _identifier_ following `.` or `->` would be first looked
up in the type of the object expression (i.e. qualified lookup), and
then in the context of the _postfix-expression_ (i.e. unqualified
lookup) if nothing was found; the result of the second lookup was
required to name a class template. Notably, this second lookup would
occur even when the object expression was dependent, and its result
would be used to determine whether a `<` token is the start of a
_template-argument_list_.
The new wording in [basic.lookup.qual.general] p2 states:
> A member-qualified name is the (unique) component name, if any, of
> - an _unqualified-id_ or
> - a _nested-name-specifier_ of the form _`type-name ::`_ or
_`namespace-name ::`_
>
> in the id-expression of a class member access expression. A
***qualified name*** is
> - a member-qualified name or
> - the terminal name of
> - a _qualified-id_,
> - a _using-declarator_,
> - a _typename-specifier_,
> - a _qualified-namespace-specifier_, or
> - a _nested-name-specifier_, _elaborated-type-specifier_, or
_class-or-decltype_ that has a _nested-name-specifier_.
>
> The _lookup context_ of a member-qualified name is the type of its
associated object expression (considered dependent if the object
expression is type-dependent). The lookup context of any other qualified
name is the type, template, or namespace nominated by the preceding
_nested-name-specifier_.
And [basic.lookup.qual.general] p3 now states:
> _Qualified name lookup_ in a class, namespace, or enumeration performs
a search of the scope associated with it except as specified below.
Unless otherwise specified, a qualified name undergoes qualified name
lookup in its lookup context from the point where it appears unless the
lookup context either is dependent and is not the current instantiation
or is not a class or class template. If nothing is found by qualified
lookup for a member-qualified name that is the terminal name of a
_nested-name-specifier_ and is not dependent, it undergoes unqualified
lookup.
In non-standardese terms, these two paragraphs essentially state the
following:
- A name that immediately follows `.` or `->` in a class member access
expression is a member-qualified name
- A member-qualified name will be first looked up in the type of the
object expression `T` unless `T` is a dependent type that is _not_ the
current instantiation, e.g.
```
template<typename T>
struct A
{
void f(T* t)
{
this->x; // type of the object expression is 'A<T>'. although 'A<T>' is dependent, it is the
// current instantiation so we look up 'x' in the template definition context.
t->y; // type of the object expression is 'T' ('->' is transformed to '.' per [expr.ref]).
// 'T' is dependent and is *not* the current instantiation, so we lookup 'y' in the
// template instantiation context.
}
};
```
- If the first lookup finds nothing and:
- the member-qualified name is the first component of a
_nested-name-specifier_ (which could be an _identifier_ or a
_simple-template-id_), and either:
- the type of the object expression is the current instantiation and it
has no dependent base classes, or
- the type of the object expression is not dependent
then we lookup the name again, this time via unqualified lookup.
Although the second (unqualified) lookup is stated not to occur when the
member-qualified name is dependent, a dependent name will _not_ be
dependent once the template is instantiated, so the second lookup must
"occur" during instantiation if qualified lookup does not find anything.
This means that we must perform the second (unqualified) lookup during
parsing even when the type of the object expression is dependent, but
those results are _not_ used to determine whether a `<` token is the
start of a _template-argument_list_; they are stored so we can replicate
the second lookup during instantiation.
In even simpler terms (paraphrasing the meeting minutes from the review of P1787; see https://wiki.edg.com/bin/view/Wg21summer2020/P1787%28Lookup%29Review2020-06-15Through2020-06-18):
- Unqualified lookup always happens for the first name in a
_nested-name-specifier_ that follows `.` or `->`
- The result of that lookup is only used to determine whether `<` is the
start of a _template-argument-list_ if the first (qualified) lookup
found nothing and the lookup context:
- is not dependent, or
- is the current instantiation and has no dependent base classes.
An example:
```
struct A
{
void f();
};
template<typename T>
using B = A;
template<typename T>
struct C : A
{
template<typename U>
void g();
void h(T* t)
{
this->g<int>(); // ok, '<' is the start of a template-argument-list ('g' was found via qualified lookup in the current instantiation)
this->B<void>::f(); // ok, '<' is the start of a template-argument-list (current instantiation has no dependent bases, 'B' was found via unqualified lookup)
t->g<int>(); // error: '<' means less than (unqualified lookup does not occur for a member-qualified name that isn't the first component of a nested-name-specifier)
t->B<void>::f(); // error: '<' means less than (unqualified lookup does not occur if the name is dependent)
t->template B<void>::f(); // ok: '<' is the start of a template-argument-list ('template' keyword used)
}
};
```
Some additional notes:
- Per [basic.lookup.qual.general] p1, lookup for a
member-qualified name only considers namespaces, types, and templates
whose specializations are types if it's an _identifier_ followed by
`::`; lookup for the component name of a _simple-template-id_ followed
by `::` is _not_ subject to this rule.
- The wording which specifies when the second unqualified lookup occurs
appears to be paradoxical. We are supposed to do it only for the first
component name of a _nested-name-specifier_ that follows `.` or `->`
when qualified lookup finds nothing. However, when that name is followed
by `<` (potentially starting a _simple-template-id_) we don't _know_
whether it will be the start of a _nested-name-specifier_ until we do
the lookup -- but we aren't supposed to do the lookup until we know it's
part of a _nested-name-specifier_! ***However***, since we only do the
second lookup when the first lookup finds nothing (and the name isn't
dependent), ***and*** since neither lookup is type-only, the only valid
option is for the name to be the _template-name_ in a
_simple-template-id_ that is followed by `::` (it can't be an
_unqualified-id_ naming a member because we already determined that the
lookup context doesn't have a member with that name). Thus, we can lock
into the _nested-name-specifier_ interpretation and do the second lookup
without having to know whether the _simple-template-id_ will be followed
by `::` yet.
This commit implements the entirety of the now-accepted [N3017
-Preprocessor
Embed](https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3017.htm) and
its sister C++ paper [p1967](https://wg21.link/p1967). It implements
everything in the specification, and includes an implementation that
drastically improves the time it takes to embed data in specific
scenarios (the initialization of character type arrays). The mechanisms
used to do this are used under the "as-if" rule, and in general when the
system cannot detect it is initializing an array object in a variable
declaration, will generate EmbedExpr AST node which will be expanded by
AST consumers (CodeGen or constant expression evaluators) or expand
embed directive as a comma expression.
This reverts commit
682d461d5a.
---------
Co-authored-by: The Phantom Derpstorm <phdofthehouse@gmail.com>
Co-authored-by: Aaron Ballman <aaron@aaronballman.com>
Co-authored-by: cor3ntin <corentinjabot@gmail.com>
Co-authored-by: H. Vetinari <h.vetinari@gmx.com>
This commit implements the entirety of the now-accepted [N3017 -
Preprocessor
Embed](https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3017.htm) and
its sister C++ paper [p1967](https://wg21.link/p1967). It implements
everything in the specification, and includes an implementation that
drastically improves the time it takes to embed data in specific
scenarios (the initialization of character type arrays). The mechanisms
used to do this are used under the "as-if" rule, and in general when the
system cannot detect it is initializing an array object in a variable
declaration, will generate EmbedExpr AST node which will be expanded
by AST consumers (CodeGen or constant expression evaluators) or
expand embed directive as a comma expression.
---------
Co-authored-by: Aaron Ballman <aaron@aaronballman.com>
Co-authored-by: cor3ntin <corentinjabot@gmail.com>
Co-authored-by: H. Vetinari <h.vetinari@gmx.com>
Co-authored-by: Podchishchaeva, Mariya <mariya.podchishchaeva@intel.com>
This patch continues previous efforts to split `Sema` up, this time
covering code completion.
Context can be found in #84184.
Dropping `Code` prefix from function names in `SemaCodeCompletion` would
make sense, but I think this PR has enough changes already.
As usual, formatting changes are done as a separate commit. Hopefully
this helps with the review.
This implementation takes quite a bit from the OMP implementation of
array sections, but only has to enforce the rules as applicable to
OpenACC. Additionally, it does its best to create an AST node (with the
assistance of RecoveryExprs) with as much checking done as soon as
possible in the case of instantiations.
OpenACC is going to need an array sections implementation that is a
simpler version/more restrictive version of the OpenMP version.
This patch moves `OMPArraySectionExpr` to `Expr.h` and renames it `ArraySectionExpr`,
then adds an enum to choose between the two.
This also fixes a couple of 'drive-by' issues that I discovered on the way,
but leaves the OpenACC Sema parts reasonably unimplemented (no semantic
analysis implementation), as that will be a followup patch.
This patch moves SYCL-related `Sema` functions into new `SemaSYCL`
class, following the recent example of OpenACC and HLSL. This is a part
of the effort to split `Sema`. Additional context can be found in
#82217, #84184, #87634.
This implements the C++23 `[[assume]]` attribute.
Assumption information is lowered to a call to `@llvm.assume`, unless the expression has side-effects, in which case it is discarded and a warning is issued to tell the user that the assumption doesn’t do anything. A failed assumption at compile time is an error (unless we are in `MSVCCompat` mode, in which case we don’t check assumptions at compile time).
Due to performance regressions in LLVM, assumptions can be disabled with the `-fno-assumptions` flag. With it, assumptions will still be parsed and checked, but no calls to `@llvm.assume` will be emitted and assumptions will not be checked at compile time.
Admittedly a bit awkward, `visionos` is the correct and accepted
spelling for annotating availability for xrOS target triples. This patch
detects errors and handles cases when `xros` is mistakenly passed.
In addition, add APIs for introduced/deprecated/obsoleted versioning in
DarwinSDKInfo mappings.
This patch implements `__is_layout_compatible` intrinsic, which supports
`std::is_layout_compatible` type trait introduced in C++20
([P0466R5](https://wg21.link/p0466r5) "Layout-compatibility and
Pointer-interconvertibility Traits"). Name matches GCC and MSVC
intrinsic.
Basically, this patch exposes our existing machinery for checking for
layout compatibility and figuring out common initial sequences. Said
machinery is a bit outdated, as it doesn't implement
[CWG1719](https://cplusplus.github.io/CWG/issues/1719.html) "Layout
compatibility and cv-qualification revisited" and
[CWG2759](https://cplusplus.github.io/CWG/issues/2759.html)
"`[[no_unique_address]` and common initial sequence". Those defect
reports are considered out of scope of of this PR, but will be
implemented in subsequent PRs.
Partially addresses #48204
Our usual pattern when issuing an extension warning is to also issue a
default-off diagnostic about the keywords not being compatible with
standards before a certain point. This adds those diagnostics for C11
keywords.
- Sema::isSimpleTypeSpecifier return true for _Bool in c99 (currently
returns false for _Bool, regardless of C dialect). (Fixes#72203)
- replace the logic with a check for simple types and a proper check for
a valid keyword in the appropriate dialect
Co-authored-by: Carl Peto <CPeto@becrypt.com>
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.
While investigating implementing 'var-list' generically for the variety
of clauses that support this syntax (an extensive list!) I discovered
that it includes 'compound types' and members of compound types, as well
as array sections.
This patch genericizes that function, and implements it in terms of an
assignment expression, and enables a simplified version of OMP Array
Sections for it. OpenACC only supports a startidx + length, so this
patch implements that parsing.
However, it is currently still being represented as an OpenMP Array
Section, which is semantically very similar. It is my intent to come
back and genericize the OMP Array Sections types (or create a similar
expression node) in the future when dealing with Sema.
At the moment, the only obvious problem with it is that the diagnostic
for using it in the 'wrong' place says OpenMP instead of OpenACC, which
I intend to fix when I deal with the AST node changes.
The data size is required for implementing the `memmove` optimization
for `std::copy`, `std::move` etc. correctly as well as replacing
`__compressed_pair` with `[[no_unique_address]]` in libc++. Since the
compiler already knows the data size, we can avoid some complexity by
exposing that information.
This patch converts `SourceLocExpr::IdentKind` into a scoped enum at namespace scope, making it eligible to be forward-declared. This is needed by `preferred_type` annotations on bit-fields.
Adds a new `__builtin_vectorelements()` function which returns the
number of elements for a given vector either at compile-time for
fixed-sized vectors, e.g., created via `__attribute__((vector_size(N)))`
or at runtime via a call to `@llvm.vscale.i32()` for scalable vectors,
e.g., SVE or RISCV V.
The new builtin follows a similar path as `sizeof()`, as it essentially
does the same thing but for the number of elements in vector instead of
the number of bytes. This allows us to re-use a lot of the existing
logic to handle types etc.
A small side addition is `Type::isSizelessVectorType()`, which we need
to distinguish between sizeless vectors (SVE, RISCV V) and sizeless
types (WASM).
This is the [corresponding
discussion](https://discourse.llvm.org/t/new-builtin-function-to-get-number-of-lanes-in-simd-vectors/73911).
The bounds of a c++ array is a _constant-expression_. And in C++ it is
also a constant expression.
But we also support VLAs, ie arrays with non-constant bounds.
We need to take care to handle the case of a consteval function (which
are specified to be only immediately called in non-constant contexts)
that appear in arrays bounds.
This introduces `Sema::isAlwayConstantEvaluatedContext`, and a flag in
ExpressionEvaluationContextRecord, such that immediate functions in
array bounds are always immediately invoked.
Sema had both `isConstantEvaluatedContext` and
`isConstantEvaluated`, so I took the opportunity to cleanup that.
The change in `TimeProfilerTest.cpp` is an unfortunate manifestation of
the problem that #66203 seeks to address.
Fixes#65520
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
This is information that the compiler already has, and should be exposed
so that the library doesn't need to reimplement the exact same
functionality.
Differential Revision: https://reviews.llvm.org/D135341
