[clang] Improve `_Alignas` on a `struct` declaration diagnostic (#65638)

Fixes https://github.com/llvm/llvm-project/issues/58637.

Adds `isAlignas()` method on `AttributeCommonInfo` which account

[clang] Improve `_Alignas` on a `struct` declaration diagnostic (#65638)

Fixes https://github.com/llvm/llvm-project/issues/58637.

Adds `isAlignas()` method on `AttributeCommonInfo` which accounts for
C++ `alignas` as well as C11 `_Alignas`.

The method is used to improve diagnostic in C when `_Alignas` is used in
C at the wrong location. This corrects the previously suggested move
of `_Alignas` past the declaration specifier, now warns attribute
`_Alignas` is ignored.

Based on https://reviews.llvm.org/D141177.

show more ...

Complete the implementation of P2361 Unevaluated string literals

The attributes changes were left out of Clang 17.
Attributes that used to take a string literal now accept an unevaluated
string lite

Complete the implementation of P2361 Unevaluated string literals

The attributes changes were left out of Clang 17.
Attributes that used to take a string literal now accept an unevaluated
string literal instead, which means they reject numeric escape sequences
and strings literal with an encoding prefix - but the later was already
ill-formed in most cases.

We need to know that we are going to parse an unevaluated string literal
before we do - so we can reject numeric escape sequence,
so we derive from Attrs.td which attributes parameters are expected
to be string literals.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D156237

show more ...

[clang] Reject non-declaration C++11 attributes on declarations

For backwards compatiblity, we emit only a warning instead of an error if the
attribute is one of the existing type attributes that we

[clang] Reject non-declaration C++11 attributes on declarations

For backwards compatiblity, we emit only a warning instead of an error if the
attribute is one of the existing type attributes that we have historically
allowed to "slide" to the `DeclSpec` just as if it had been specified in GNU
syntax. (We will call these "legacy type attributes" below.)

The high-level changes that achieve this are:

- We introduce a new field `Declarator::DeclarationAttrs` (with appropriate
accessors) to store C++11 attributes occurring in the attribute-specifier-seq
at the beginning of a simple-declaration (and other similar declarations).
Previously, these attributes were placed on the `DeclSpec`, which made it
impossible to reconstruct later on whether the attributes had in fact been
placed on the decl-specifier-seq or ahead of the declaration.

- In the parser, we propgate declaration attributes and decl-specifier-seq
attributes separately until we can place them in
`Declarator::DeclarationAttrs` or `DeclSpec::Attrs`, respectively.

- In `ProcessDeclAttributes()`, in addition to processing declarator attributes,
we now also process the attributes from `Declarator::DeclarationAttrs` (except
if they are legacy type attributes).

- In `ConvertDeclSpecToType()`, in addition to processing `DeclSpec` attributes,
we also process any legacy type attributes that occur in
`Declarator::DeclarationAttrs` (and emit a warning).

- We make `ProcessDeclAttribute` emit an error if it sees any non-declaration
attributes in C++11 syntax, except in the following cases:
- If it is being called for attributes on a `DeclSpec` or `DeclaratorChunk`
- If the attribute is a legacy type attribute (in which case we only emit
a warning)

The standard justifies treating attributes at the beginning of a
simple-declaration and attributes after a declarator-id the same. Here are some
relevant parts of the standard:

- The attribute-specifier-seq at the beginning of a simple-declaration
"appertains to each of the entities declared by the declarators of the
init-declarator-list" (https://eel.is/c++draft/dcl.dcl#dcl.pre-3)

- "In the declaration for an entity, attributes appertaining to that entity can
appear at the start of the declaration and after the declarator-id for that
declaration." (https://eel.is/c++draft/dcl.dcl#dcl.pre-note-2)

- "The optional attribute-specifier-seq following a declarator-id appertains to
the entity that is declared."
(https://eel.is/c++draft/dcl.dcl#dcl.meaning.general-1)

The standard contains similar wording to that for a simple-declaration in other
similar types of declarations, for example:

- "The optional attribute-specifier-seq in a parameter-declaration appertains to
the parameter." (https://eel.is/c++draft/dcl.fct#3)

- "The optional attribute-specifier-seq in an exception-declaration appertains
to the parameter of the catch clause" (https://eel.is/c++draft/except.pre#1)

The new behavior is tested both on the newly added type attribute
`annotate_type`, for which we emit errors, and for the legacy type attribute
`address_space` (chosen somewhat randomly from the various legacy type
attributes), for which we emit warnings.

Depends On D111548

Reviewed By: aaron.ballman, rsmith

Differential Revision: https://reviews.llvm.org/D126061

show more ...

Allow parameter pack expansions and initializer lists in annotate attribute

These changes make the Clang parser recognize expression parameter pack
expansion and initializer lists in attribute argum

Allow parameter pack expansions and initializer lists in annotate attribute

These changes make the Clang parser recognize expression parameter pack
expansion and initializer lists in attribute arguments. Because
expression parameter pack expansion requires additional handling while
creating and instantiating templates, the support for them must be
explicitly supported through the AcceptsExprPack flag.

Handling expression pack expansions may require a delay to when the
arguments of an attribute are correctly populated. To this end,
attributes that are set to accept these - through setting the
AcceptsExprPack flag - will automatically have an additional variadic
expression argument member named DelayedArgs. This member is not
exposed the same way other arguments are but is set through the new
CreateWithDelayedArgs creator function generated for applicable
attributes.

To illustrate how to implement support for expression pack expansion
support, clang::annotate is made to support pack expansions. This is
done by making handleAnnotationAttr delay setting the actual attribute
arguments until after template instantiation if it was unable to
populate the arguments due to dependencies in the parsed expressions.

show more ...

[Parse] Use empty RecoveryExpr when if/while/do/switch conditions fail to parse

This allows the body to be parsed.
An special-case that would replace a missing if condition with OpaqueValueExpr
was

[Parse] Use empty RecoveryExpr when if/while/do/switch conditions fail to parse

This allows the body to be parsed.
An special-case that would replace a missing if condition with OpaqueValueExpr
was removed as it's now redundant (unless recovery-expr is disabled).

For loops are not handled at this point, as the parsing is more complicated.

Differential Revision: https://reviews.llvm.org/D113752

show more ...

[clang][Parse] Add parsing support for C++ attributes on using-declarations

This is a re-application of dc67299 which was reverted in f63adf5b because
it broke the build. The issue should now be fix

[clang][Parse] Add parsing support for C++ attributes on using-declarations

This is a re-application of dc67299 which was reverted in f63adf5b because
it broke the build. The issue should now be fixed.

Attribution note: The original author of this patch is Erik Pilkington.
I'm only trying to land it after rebasing.

Differential Revision: https://reviews.llvm.org/D91630

show more ...

Revert "[clang][Parse] Add parsing support for C++ attributes on using-declarations"

This reverts commit dc672999a9b12a156991891dc400308b52d569ba.
Breaks check-clang everywhere, see https://reviews.

Revert "[clang][Parse] Add parsing support for C++ attributes on using-declarations"

This reverts commit dc672999a9b12a156991891dc400308b52d569ba.
Breaks check-clang everywhere, see https://reviews.llvm.org/D91630

show more ...

[clang][Parse] Add parsing support for C++ attributes on using-declarations

Differential Revision: https://reviews.llvm.org/D91630

Speculative fix for failing build bot.

This attempts to resolve an issue found by http://45.33.8.238/macm1/6821/step_6.txt

[clang][parser] Set source ranges for GNU-style attributes

Set the source ranges for parsed GNU-style attributes in
ParseGNUAttributes(), the same way that ParseCXX11Attributes() does it.

Different

[clang][parser] Set source ranges for GNU-style attributes

Set the source ranges for parsed GNU-style attributes in
ParseGNUAttributes(), the same way that ParseCXX11Attributes() does it.

Differential Revision: https://reviews.llvm.org/D75844

show more ...

[clang][parser] Allow GNU-style attributes in explicit template...

... instantiations

They are currently not being diagnosed because ProhibitAttributes() does
not handle attribute lists with an inv

[clang][parser] Allow GNU-style attributes in explicit template...

... instantiations

They are currently not being diagnosed because ProhibitAttributes() does
not handle attribute lists with an invalid source range. But once it
does, we need to allow GNU attributes in this place.

Additionally, start optionally diagnosing empty attr lists in
ProhibitCXX11Attributes(), since ProhibitAttribute() does it.

Differential Revision: https://reviews.llvm.org/D97362

show more ...

Introduce the _Clang scoped attribute token.

Currently, we only accept clang as the scoped attribute identifier for double square bracket attributes provided by Clang, but this has the potential to

Introduce the _Clang scoped attribute token.

Currently, we only accept clang as the scoped attribute identifier for double square bracket attributes provided by Clang, but this has the potential to conflict with user-defined macros. To help alleviate these concerns, this introduces the _Clang scoped attribute identifier as an alias for clang. It also introduces a warning with a fixit on the off chance someone attempts to use __clang__ as the scoped attribute (which is a predefined compiler identification macro).

llvm-svn: 346521

show more ...

Add a fixit for attributes incorrectly placed prior to 'struct/class/enum' keyword.

Suggest moving the following erroneous attrib list (based on location)
[[]] struct X;
to
struct [[]] X;

Additi

Add a fixit for attributes incorrectly placed prior to 'struct/class/enum' keyword.

Suggest moving the following erroneous attrib list (based on location)
[[]] struct X;
to
struct [[]] X;

Additionally, added a fixme for the current implementation that diagnoses misplaced attributes to consider using the newly introduced diagnostic (that I think is more user-friendly).

llvm-svn: 321449

show more ...

Determine the attribute subject for diagnostics based on declarative information in DeclNodes.td. This greatly reduces the number of enumerated values used for more complex diagnostics; these are now

Determine the attribute subject for diagnostics based on declarative information in DeclNodes.td. This greatly reduces the number of enumerated values used for more complex diagnostics; these are now only required when the "attribute only applies to" diagnostic needs to be generated manually as part of semantic processing.

This also clarifies some terminology used by the diagnostic (methods -> Objective-C methods, fields -> non-static data members, etc).

Many of the tests needed to be updated in multiple places for the diagnostic wording tweaks. The first instance of the diagnostic for that attribute is fully specified and subsequent instances cut off the complete list (to make it easier if additional subjects are added in the future for the attribute).

llvm-svn: 319002

show more ...

Fix backwards warning for use of C++17 attributes-on-namespaces-and-enumerators feature.

llvm-svn: 315784

Replace remaining user-visible mentions of C++1z with C++17.

llvm-svn: 310804

Fix constructor declarator detection for the case when the name is followed by
an attribute-specifier-seq. (Also fixes the same problem for deduction-guides.)

llvm-svn: 294396

Silence duplicate diagnostics because parsing of a standards-based attribute triggers parsing diagnostics that may also be picked up during semantic analysis.

llvm-svn: 262960

P0188R1: add support for standard [[fallthrough]] attribute. This is almost
exactly the same as clang's existing [[clang::fallthrough]] attribute, which
has been updated to have the same semantics. T

P0188R1: add support for standard [[fallthrough]] attribute. This is almost
exactly the same as clang's existing [[clang::fallthrough]] attribute, which
has been updated to have the same semantics. The one significant difference
is that [[fallthrough]] is ill-formed if it's not used immediately before a
switch label (even when -Wimplicit-fallthrough is disabled). To support that,
we now build a CFG of any function that uses a '[[fallthrough]];' statement
to check.

In passing, fix some bugs with our support for statement attributes -- in
particular, diagnose their use on declarations, rather than asserting.

llvm-svn: 262881

show more ...

[Sema] Tweak incomplete enum types on MSVC ABI targets

Enums without an explicit, fixed, underlying type are implicitly given a
fixed 'int' type for ABI compatibility with MSVC. However, we can
enf

[Sema] Tweak incomplete enum types on MSVC ABI targets

Enums without an explicit, fixed, underlying type are implicitly given a
fixed 'int' type for ABI compatibility with MSVC. However, we can
enforce the standard-mandated rules on these types as-if we didn't know
this fact if the tag is not part of a definition.

llvm-svn: 249667

show more ...

Update tests touched by r249656

These test updates almost exclusively around the change in behavior
around enum: enums without a definition are considered incomplete except
when targeting MSVC ABIs.

Update tests touched by r249656

These test updates almost exclusively around the change in behavior
around enum: enums without a definition are considered incomplete except
when targeting MSVC ABIs. Since these tests are interested in the
'incomplete-enum' behavior, restrict them to %itanium_abi_triple.

llvm-svn: 249660

show more ...

[parse] Don't crash on alternative operator spellings from macros in c++11 attributes.

Found by afl-fuzz.

llvm-svn: 233499

Minor tweaks to r229447 to ensure the attribute is properly quoted when diagnosed.

llvm-svn: 229454

Sema: diagnose use of unscoped deprecated prior to C++14

The deprecated attribute was adopted as part of the C++14, however, there is a
GNU version available in C++11. When using C++ earlier than C

Sema: diagnose use of unscoped deprecated prior to C++14

The deprecated attribute was adopted as part of the C++14, however, there is a
GNU version available in C++11. When using C++ earlier than C++14, diagnose the
use of the attribute without the GNU scope, but only when using the generalised
attribute syntax.

llvm-svn: 229447

show more ...

Parse: Don't crash when an annotation token shows up in a C++11 attr

It's not safe to blindly call getIdentifierInfo without checking the
token is not an annotation token.

llvm-svn: 225533