This patch adds the Parse and Sema support for RegularKeyword attributes,
following on from a previous patch that added Attr.td support.
The patch is quite large. However, nothing outside the tests is
specific to the first RegularKeyword attribute (__arm_streaming).
The patch should therefore be a one-off, up-front cost. Other
attributes just need an entry in Attr.td and the usual Sema support.
The approach taken in the patch is that the keywords can be used with
any language version. If standard attributes were added in language
version Y, the keyword rules for version X<Y are the same as they were
for version Y (to the extent possible). Any extensions beyond Y are
handled in the same way for both keywords and attributes. This ensures
that existing C++11 successors like C++17 are not treated differently
from versions that have yet to be defined.
Some notes on the implementation:
* The patch emits errors rather than warnings for diagnostics that
relate to keywords.
* Where possible, the patch drops “attribute” from diagnostics
relating to keywords.
* One exception to the previous point is that warnings about C++
extensions do still mention attributes. The use there seemed OK
since the diagnostics are noting a change in the production rules.
* If a diagnostic string needs to be different for keywords and
attributes, the patch standardizes on passing the attribute/
name/token followed by 0 for attributes and 1 for keywords.
* Although the patch updates warn_attribute_wrong_decl_type_str,
warn_attribute_wrong_decl_type, and warn_attribute_wrong_decl_type,
only the error forms of these strings are used for keywords.
* I couldn't trigger the warnings in checkUnusedDeclAttributes,
even for existing attributes. An assert on the warnings caused
no failures in the testsuite. I think in practice all standard
attributes would be diagnosed before this.
* The patch drops a call to standardAttributesAllowed in
ParseFunctionDeclarator. This is because MaybeParseCXX11Attributes
checks the same thing itself, where appropriate.
* The new tests are based on c2x-attributes.c and
cxx0x-attributes.cpp. The C++ test also incorporates a version of
cxx11-base-spec-attributes.cpp. The FIXMEs are carried across from
the originals.
Differential Revision: https://reviews.llvm.org/D148702
During the ISO C++ Committee meeting plenary session the C++23 Standard
has been voted as technical complete.
This updates the reference to c++2b to c++23 and updates the __cplusplus
macro.
Drive-by fixes c++1z -> c++17 and c++2a -> c++20 when seen.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D149553
Sema.h is huge. This makes a small reduction to it by moving
EnterExpressionEvaluationContext into a new header, since it is an
independent component.
Differential Revision: https://reviews.llvm.org/D149796
Since this was originally a name in library, it needs an escape hatch
for versions of Clang that are slightly out-of-sync with libc++.
Differential Revision: https://reviews.llvm.org/D148677
This patch adds static functions for constructing most
AttributeCommonInfo::Forms. Direct construction is only retained where
all fields (currently the syntax and spelling) are specified explicitly.
This is a wash on its own. The purpose is to allow extra fields
to be added to Form without disrupting all callers. In particular,
it allows extra information to be stored about keywords without
affecting non-keyword uses.
No functional change intended.
Differential Revision: https://reviews.llvm.org/D148104
This patch adds an extra AttributeCommonInfo::Form constructor
for keywords, represented by their TokenKind. This isn't a
win on its own, but it helps with later patches.
No functional change intended.
Differential Revision: https://reviews.llvm.org/D148103
This implements WG14 N2934
(https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2934.pdf), which
adds keywords for alignas, alignof, bool, static_assert, and
thread_local in C, as aliases for _Alignas, _Alignof, _Bool,
_Static_assert, and _Thread_local. We already supported the keywords in
C2x mode, but this completes support by adding pre-C2x compat warnings
and updates the stdalign.h header in freestanding mode.
As the diagnostic message shows, we should remove -fmodules-ts flag in
clang/llvm17. Since clang/llvm16 is already branched. We can remove the
depreacared flag now.
This reverts commit e70ca7b35319a3621f9d9c6475926428f8c5c000 and the
followup patch "[clang] Fix the location of UsingTypeLoc"
(ebbeb164c25a40cb6ba9c6b18dce5dcd06c0bb07).
The patch causes an incorrect lookup result:
```
namespace ns { struct Foo { };}
using ns::Foo;
void test() {
struct Foo {
} k; // the type of k refers to ns::Foo, rather than the local Foo!
}
```
Support building UsingType for elaborated type specifiers:
```
namespace ns { class Foo {}; }
using ns::Foo;
// The TypeLoc of `Foo` below should be a ElaboratedTypeLoc with an
// inner UsingTypeLoc rather than the underlying `CXXRecordTypeLoc`
class Foo foo;
```
Differential Revision: https://reviews.llvm.org/D141280
https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2350.htm made very
clear that it is an UB having type definitions with in offsetof.
Clang supports defining a type as the first argument as a conforming
extension due to how many projects use the construct in C99 and earlier
to calculate the alignment of a type. GCC also supports defining a type
as the first argument.
This adds extension warnings and documentation for the functionality
Clang explicitly supports.
Fixes#57065
Reverts the revert of 39da55e8f548a11f7dadefa73ea73d809a5f1729
Co-authored-by: Yingchi Long <i@lyc.dev>
Co-authored-by: Aaron Ballman <aaron@aaronballman.com>
Differential Revision: https://reviews.llvm.org/D133574
https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2350.htm made very
clear that it is an UB having type definitions with in offsetof.
Clang supports defining a type as the first argument as a conforming
extension due to how many projects use the construct in C99 and earlier
to calculate the alignment of a type. GCC also supports defining a type
as the first argument.
This adds extension warnings and documentation for the functionality
Clang explicitly supports.
Fixes#57065
Co-authored-by: Yingchi Long <i@lyc.dev>
Co-authored-by: Aaron Ballman <aaron@aaronballman.com>
Implement https://cplusplus.github.io/CWG/issues/2631.html.
Immediate calls in default arguments and defaults members
are not evaluated.
Instead, we evaluate them when constructing a
`CXXDefaultArgExpr`/`BuildCXXDefaultInitExpr`.
The immediate calls are executed by doing a
transform on the initializing expression.
Note that lambdas are not considering subexpressions so
we do not need to transform them.
As a result of this patch, unused default member
initializers are not considered odr-used, and
errors about members binding to local variables
in an outer scope only surface at the point
where a constructor is defined.
Reviewed By: aaron.ballman, #clang-language-wg, rupprecht
Differential Revision: https://reviews.llvm.org/D136554
clang would improperly disallow GNU attributes before C++ standard
attributes when a declaration had a linkage specifier. Handle this
similarly to the previous case of invalid parsing. We now better match
the parsing rules from GCC.
Differential Revision: https://reviews.llvm.org/D140507
Reviewed By: aaron.ballman
This reverts commit f1f1b60c7ba607e9ffe3bc012161d43ef95ac773.
Temporary revert, possibly triggers a new assertion failure on
QualType::getCommonPtr.
We're working on a reproducer, to follow-up on
https://reviews.llvm.org/D136554.
Implement https://cplusplus.github.io/CWG/issues/2631.html.
Immediate calls in default arguments and defaults members
are not evaluated.
Instead, we evaluate them when constructing a
`CXXDefaultArgExpr`/`BuildCXXDefaultInitExpr`.
The immediate calls are executed by doing a
transform on the initializing expression.
Note that lambdas are not considering subexpressions so
we do not need to transform them.
As a result of this patch, unused default member
initializers are not considered odr-used, and
errors about members binding to local variables
in an outer scope only surface at the point
where a constructor is defined.
Reviewed By: aaron.ballman, #clang-language-wg
Differential Revision: https://reviews.llvm.org/D136554
Implement https://cplusplus.github.io/CWG/issues/2631.html.
Immediate calls in default arguments and defaults members
are not evaluated.
Instead, we evaluate them when constructing a
`CXXDefaultArgExpr`/`BuildCXXDefaultInitExpr`.
The immediate calls are executed by doing a
transform on the initializing expression.
Note that lambdas are not considering subexpressions so
we do not need to transform them.
As a result of this patch, unused default member
initializers are not considered odr-used, and
errors about members binding to local variables
in an outer scope only surface at the point
where a constructor is defined.
Reviewed By: aaron.ballman, #clang-language-wg
Differential Revision: https://reviews.llvm.org/D136554
Implement https://cplusplus.github.io/CWG/issues/2631.html.
Immediate calls in default arguments and defaults members
are not evaluated.
Instead, we evaluate them when constructing a
`CXXDefaultArgExpr`/`BuildCXXDefaultInitExpr`.
The immediate calls are executed by doing a
transform on the initializing expression.
Note that lambdas are not considering subexpressions so
we do not need to transform them.
As a result of this patch, unused default member
initializers are not considered odr-used, and
errors about members binding to local variables
in an outer scope only surface at the point
where a constructor is defined.
Reviewed By: aaron.ballman, #clang-language-wg
Differential Revision: https://reviews.llvm.org/D136554
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated. The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.
This is part of an effort to migrate from llvm::Optional to
std::optional:
https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
This reverts commit 26fa17ed2914bd80c066d36b325fd3104e45554c.
This reverts commit 4403c4f9e77e673a2771edfc7ab0ebb234e97485.
There is still an ODR issue causing linker errors, investigating.
Implement https://cplusplus.github.io/CWG/issues/2631.html.
Immediate calls in default arguments and defaults members
are not evaluated.
Instead, we evaluate them when constructing a
`CXXDefaultArgExpr`/`BuildCXXDefaultInitExpr`.
The immediate calls are executed by doing a
transform on the initializing expression.
Note that lambdas are not considering subexpressions so
we do not need to transform them.
As a result of this patch, unused default member
initializers are not considered odr-used, and
errors about members binding to local variables
in an outer scope only surface at the point
where a constructor is defined.
Reviewed By: aaron.ballman, #clang-language-wg
Differential Revision: https://reviews.llvm.org/D136554
Adds support for NamespaceDecl to inform if its part of a nested namespace.
This flag only corresponds to the inner namespaces in a nested namespace declaration.
In this example:
namespace <X>::<Y>::<Z> {}
Only <Y> and <Z> will be classified as nested.
This flag isn't meant for assisting in building the AST, more for static analysis and refactorings.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D90568
We would previously reject valid input where GNU attributes preceded the
standard attributes on top-level declarations. A previous attribute
handling change had begun rejecting this whilst GCC does honour this
layout. In practice, this breaks use of `extern "C"` attributed
functions which use both standard and GNU attributes as experienced by
the Swift runtime.
Objective-C deserves an honourable mention for requiring some additional
special casing. Because attributes on declarations and definitions
differ in semantics, we need to replicate some of the logic for
detecting attributes to declarations to which they appertain cannot be
attributed. This should match the existing case for the application of
GNU attributes to interfaces, protocols, and implementations.
Take the opportunity to split out the tooling tests into two cases: ones
which process macros and ones which do not.
Special thanks to Aaron Ballman for the many hints and extensive rubber
ducking that was involved in identifying the various places where we
accidentally dropped attributes.
Differential Revision: https://reviews.llvm.org/D137979Fixes: #58229
Reviewed By: aaron.ballman, arphaman
This reverts commit 7acfe3629479c8489fc2d7f629994dc200be990c.
This reverts commit 5f87a892a7bed9cb0599573b9aaf387bc1df9c14.
This reverts commit 6875ac69279a3a02fab382a2c8d121558ecbfa91.
Implement https://cplusplus.github.io/CWG/issues/2631.html.
Immediate calls in default arguments and defaults members
are not evaluated.
Instead, we evaluate them when constructing a
`CXXDefaultArgExpr`/`BuildCXXDefaultInitExpr`.
The immediate calls are executed by doing a
transform on the initializing expression.
Note that lambdas are not considering subexpressions so
we do not need to transform them.
As a result of this patch, unused default member
initializers are not considered odr-used, and
errors about members binding to local variables
in an outer scope only surface at the point
where a constructor is defined.
Reviewed By: aaron.ballman, #clang-language-wg
Differential Revision: https://reviews.llvm.org/D136554
Implement https://cplusplus.github.io/CWG/issues/2631.html.
Immediate calls in default arguments and defaults members
are not evaluated.
Instead, we evaluate them when constructing a
`CXXDefaultArgExpr`/`BuildCXXDefaultInitExpr`.
The immediate calls are executed by doing a
transform on the initializing expression.
Note that lambdas are not considering subexpressions so
we do not need to transform them.
As a result of this patch, unused default member
initializers are not considered odr-used, and
errors about members binding to local variables
in an outer scope only surface at the point
where a constructor is defined.
Reviewed By: aaron.ballman, #clang-language-wg
Differential Revision: https://reviews.llvm.org/D136554
... as builtins.
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.
This was originally a part of D116280.
Depends on D135175.
Differential Revision: https://reviews.llvm.org/D135177
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.
This was originally a part of D116280.
Differential Revision: https://reviews.llvm.org/D135175
This patch implements P0634r3 that removes the need for 'typename' in certain contexts.
For example,
```
template <typename T>
using foo = T::type; // ok
```
This is also allowed in previous language versions as an extension, because I think it's pretty useful. :)
Reviewed By: #clang-language-wg, erichkeane
Differential Revision: https://reviews.llvm.org/D53847
Although using-enum's grammar is 'using elaborated-enum-specifier',
the lookup for the enum is ordinary lookup (and not the tagged-type
lookup that normally occurs wth an tagged-type specifier). Thus (a)
we can find typedefs and (b) do not find enum tags hidden by a non-tag
name (the struct stat thing).
This reimplements that part of using-enum handling, to address DR2621,
where clang's behaviour does not match std intent (and other
compilers).
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D134283
The patch diagnoses an identifier as a future keyword if it exists in a
future language mode, such as:
int restrict;
in C modes earlier than C99. We now give a warning to the user that
such an identifier is a future keyword. Handles keywords from C as well
as C++.
Differential Revision: https://reviews.llvm.org/D131683
Adds
* `__add_lvalue_reference`
* `__add_pointer`
* `__add_rvalue_reference`
* `__decay`
* `__make_signed`
* `__make_unsigned`
* `__remove_all_extents`
* `__remove_extent`
* `__remove_const`
* `__remove_volatile`
* `__remove_cv`
* `__remove_pointer`
* `__remove_reference`
* `__remove_cvref`
These are all compiler built-in equivalents of the unary type traits
found in [[meta.trans]][1]. The compiler already has all of the
information it needs to answer these transformations, so we can skip
needing to make partial specialisations in standard library
implementations (we already do this for a lot of the query traits). This
will hopefully improve compile times, as we won't need use as much
memory in such a base part of the standard library.
[1]: http://wg21.link/meta.trans
Co-authored-by: zoecarver
Reviewed By: aaron.ballman, rsmith
Differential Revision: https://reviews.llvm.org/D116203
This reverts commit bc60cf2368de90918719dc7e3d7c63a72cc007ad.
Doesn't build on Windows and breaks gcc 9 build, see
https://reviews.llvm.org/D116203#3722094 and
https://reviews.llvm.org/D116203#3722128
Also revert two follow-ups. One fixed a warning added in
bc60cf2368de90918719dc7e3d7c63a72cc007ad, the other
makes use of the feature added in bc60cf2368de90918719dc7e3d7c63a72cc007ad
in libc++:
Revert "[libcxx][NFC] utilises compiler builtins for unary transform type-traits"
This reverts commit 06a1d917ef1f507aaa2f6891bb654696c866ea3a.
Revert "[Sema] Fix a warning"
This reverts commit c85abbe879ef3257de4db862ce249b060cc3d2a4.
Adds
* `__add_lvalue_reference`
* `__add_pointer`
* `__add_rvalue_reference`
* `__decay`
* `__make_signed`
* `__make_unsigned`
* `__remove_all_extents`
* `__remove_extent`
* `__remove_const`
* `__remove_volatile`
* `__remove_cv`
* `__remove_pointer`
* `__remove_reference`
* `__remove_cvref`
These are all compiler built-in equivalents of the unary type traits
found in [[meta.trans]][1]. The compiler already has all of the
information it needs to answer these transformations, so we can skip
needing to make partial specialisations in standard library
implementations (we already do this for a lot of the query traits). This
will hopefully improve compile times, as we won't need use as much
memory in such a base part of the standard library.
[1]: http://wg21.link/meta.trans
Co-authored-by: zoecarver
Reviewed By: aaron.ballman, rsmith
Differential Revision: https://reviews.llvm.org/D116203
This patch rewords the static assert diagnostic output. Failing a
_Static_assert in C should not report that static_assert failed. This
changes the wording to be more like GCC and uses "static assertion"
when possible instead of hard coding the name. This also changes some
instances of 'static_assert' to instead be based on the token in the
source code.
Differential Revision: https://reviews.llvm.org/D129048
Looks like we again are going to have problems with libcxx tests that
are overly specific in their dependency on clang's diagnostics.
This reverts commit 6542cb55a3eb115b1c3592514590a19987ffc498.
