Commit Graph

1083 Commits

Author SHA1 Message Date
Haojian Wu 6e63f96e11 [Parse] Improve diagnostic and recovery when there is an extra override in the outline method definition.
The clang behavior was poor before this patch:

```
void B::foo() override {}
// Before: clang emited "expcted function body after function
// declarator", and skiped all contents until it hits a ";", the
// following function f() is discarded.

// VS

// Now "override is not allowed" with a remove fixit, and following f()
// is retained.
void f();
```

Differential Revision: https://reviews.llvm.org/D111883
2021-10-18 10:00:21 +02:00
Qiu Chaofan fae0dfa642 [Clang] Add __ibm128 type to represent ppc_fp128
Currently, we have no front-end type for ppc_fp128 type in IR. PowerPC
target generates ppc_fp128 type from long double now, but there's option
(-mabi=(ieee|ibm)longdouble) to control it and we're going to do
transition from IBM extended double-double ppc_fp128 to IEEE fp128 in
the future.

This patch adds type __ibm128 which always represents ppc_fp128 in IR,
as what GCC did for that type. Without this type in Clang, compilation
will fail if compiling against future version of libstdcxx (which uses
__ibm128 in headers).

Although all operations in backend for __ibm128 is done by software,
only PowerPC enables support for it.

There's something not implemented in this commit, which can be done in
future ones:

- Literal suffix for __ibm128 type. w/W is suitable as GCC documented.
- __attribute__((mode(IF))) should be for __ibm128.
- Complex __ibm128 type.

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D93377
2021-09-06 18:00:58 +08:00
Justas Janickas f9bc1b3bee [OpenCL] Defines helper function for kernel language compatible OpenCL version
This change defines a helper function getOpenCLCompatibleVersion()
inside LangOptions class. The function contains mapping between
C++ for OpenCL versions and their corresponding compatible OpenCL
versions. This mapping function should be updated each time a new
C++ for OpenCL language version is introduced. The helper function
is expected to simplify conditions on OpenCL C and C++ for OpenCL
versions inside compiler code.

Code refactoring performed.

Differential Revision: https://reviews.llvm.org/D108693
2021-08-31 10:08:38 +01:00
Justas Janickas cfdfb75c1f [OpenCL] Clang diagnostics allow reporting C++ for OpenCL version.
Some Clang diagnostics could only report OpenCL C version. Because
C++ for OpenCL can be used as an alternative to OpenCL C, the text
for diagnostics should reflect that.

Desrciptions modified for these diagnostics:
`err_opencl_unknown_type_specifier`
`warn_option_invalid_ocl_version`
`err_attribute_requires_opencl_version`
`warn_opencl_attr_deprecated_ignored`
`ext_opencl_ext_vector_type_rgba_selector`

Differential Revision: https://reviews.llvm.org/D107648
2021-08-13 13:55:22 +01:00
Sam McCall ece4e92085 [CodeComplete] Basic code completion for attribute names.
Only the bare name is completed, with no args.
For args to be useful we need arg names. These *are* in the tablegen but
not currently emitted in usable form, so left this as future work.

C++11, C2x, GNU, declspec, MS syntax is supported, with the appropriate
spellings of attributes suggested.
`#pragma clang attribute` is supported but not terribly useful as we
only reach completion if parens are balanced (i.e. the line is not truncated)

There's no filtering of which attributes might make sense in this
grammatical context (e.g. attached to a function). In code-completion context
this is hard to do, and will only work in few cases :-(

There's also no filtering by langopts: this is because currently the
only way of checking is to try to produce diagnostics, which requires a
valid ParsedAttr which is hard to get.
This should be fairly simple to fix but requires some tablegen changes
to expose the logic without the side-effect.

Differential Revision: https://reviews.llvm.org/D107696
2021-08-12 23:49:10 +02:00
Alex Orlov 638dcea010 [clang] Implement P0692R1 from C++20 (access checking on specializations and instantiations)
This patch implements paper P0692R1 from the C++20 standard. Disable usual access checking rules to template argument names in a declaration of partial specializations, explicit instantiation or explicit specialization (C++20 13.7.5/10, 13.9.1/6).
Fixes: https://llvm.org/PR37424
This patch also implements option *A* from this paper P0692R1 from the C++20 standard.
This patch follows the @rsmith suggestion from D78404.

Reviewed By: krisb

Differential Revision: https://reviews.llvm.org/D92024
2021-08-10 19:20:50 +04:00
Anton Zabaznov acc5850495 [OpenCL] Add support of __opencl_c_pipes feature macro.
'pipe' keyword is introduced in OpenCL C 2.0: so do checks for OpenCL C version while
parsing and then later on check for language options to construct actual pipe. This feature
requires support of __opencl_c_generic_address_space, so diagnostics for that is provided as well.

This is the same patch as in D106748 but with a tiny fix in checking of diagnostic messages.
Also added tests when program scope global variables are not supported.

Reviewed By: Anastasia

Differential Revision: https://reviews.llvm.org/D107154
2021-07-30 18:10:25 +03:00
Anton Zabaznov da6626d126 Revert "[OpenCL] Add support of __opencl_c_pipes feature macro."
This reverts commit d1e4b25756.
2021-07-30 06:34:29 +03:00
Anton Zabaznov d1e4b25756 [OpenCL] Add support of __opencl_c_pipes feature macro.
'pipe' keyword is introduced in OpenCL C 2.0: so do checks for OpenCL C version while
parsing and then later on check for language options to construct actual pipe. This feature
requires support of __opencl_c_generic_address_space, so diagnostics for that is provided as well.

Reviewed By: Anastasia

Differential Revision: https://reviews.llvm.org/D106748
2021-07-30 05:27:55 +03:00
Anton Zabaznov 78463ebde2 [OpenCL] Add support of __opencl_c_generic_address_space feature macro
Reviewed By: Anastasia

Differential Revision: https://reviews.llvm.org/D103401
2021-07-13 13:14:10 +03:00
Aaron Ballman de59f56440 [OpenMP] Support OpenMP 5.1 attributes
OpenMP 5.1 added support for writing OpenMP directives using [[]]
syntax in addition to using #pragma and this introduces support for the
new syntax.

In OpenMP, the attributes take one of two forms:
[[omp::directive(...)]] or [[omp::sequence(...)]]. A directive
attribute contains an OpenMP directive clause that is identical to the
analogous #pragma syntax. A sequence attribute can contain either
sequence or directive arguments and is used to ensure that the
attributes are processed sequentially for situations where the order of
the attributes matter (remember:
https://eel.is/c++draft/dcl.attr.grammar#4.sentence-4).

The approach taken here is somewhat novel and deserves mention. We
could refactor much of the OpenMP parsing logic to work for either
pragma annotation tokens or for attribute clauses. It would be a fair
amount of effort to share the logic for both, but it's certainly
doable. However, the semantic attribute system is not designed to
handle the arbitrarily complex arguments that OpenMP directives
contain. Adding support to thread the novel parsed information until we
can produce a semantic attribute would be considerably more effort.
What's more, existing OpenMP constructs are not (often) represented as
semantic attributes. So doing this through Attr.td would be a massive
undertaking that would likely only benefit OpenMP and comes with
additional risks. Rather than walk down that path, I am taking
advantage of the fact that the syntax of the directives within the
directive clause is identical to that of the #pragma form. Once the
parser recognizes that we're processing an OpenMP attribute, it caches
all of the directive argument tokens and then replays them as though
the user wrote a pragma. This reuses the same OpenMP parsing and
semantic logic directly, but does come with a risk if the OpenMP
committee decides to purposefully diverge their pragma and attribute
syntaxes. So, despite this being a novel approach that does token
replay, I think it's actually a better approach than trying to do this
through the declarative syntax in Attr.td.
2021-07-12 06:51:19 -04:00
Louis Dionne 97d234935f [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
2021-06-01 08:47:50 -04:00
Nico Weber f63adf5b67 Revert "[clang][Parse] Add parsing support for C++ attributes on using-declarations"
This reverts commit dc672999a9.
Breaks check-clang everywhere, see https://reviews.llvm.org/D91630
2021-05-28 14:49:18 -04:00
Erik Pilkington dc672999a9 [clang][Parse] Add parsing support for C++ attributes on using-declarations
Differential Revision: https://reviews.llvm.org/D91630
2021-05-28 12:00:33 -04:00
Zarko Todorovski 8fa168fc50 Parse vector bool when stdbool.h and altivec.h are included
Currently when including stdbool.h and altivec.h declaration of `vector bool` leads to
errors due to `bool` being expanded to '_Bool`. This patch allows the parser
to recognize `_Bool`.

Reviewed By: hubert.reinterpretcast, Everybody0523

Differential Revision: https://reviews.llvm.org/D102064
2021-05-13 11:48:32 -04:00
Anastasia Stulova 76f1de10f4 [OpenCL] Fix optional image types.
This change allows the use of identifiers for image types
from `cl_khr_gl_msaa_sharing` freely in the kernel code if
the extension is not supported since they are not in the
list of the reserved identifiers.

This change also removed the need for pragma for the types
in the extensions since the spec does not require the pragma
uses.

Differential Revision: https://reviews.llvm.org/D100983
2021-05-07 13:29:28 +01:00
Anastasia Stulova 64911eec75 [OpenCL] Allow pipe as a valid identifier prior to OpenCL 2.0.
Pipe has not been a reserved keyword in the earlier OpenCL
standards. However we failed to allow its use as an identifier
in the original commit. This issues is fixed now and testing
is improved accordingly.

Differential Revision: https://reviews.llvm.org/D101052
2021-05-04 14:30:42 +01:00
Timm Bäder 1b4800c262 [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
2021-04-04 07:59:22 +02:00
Timm Bäder 908a267b5a Revert "[clang][parser] Set source ranges for GNU-style attributes"
This reverts commit 1ea9fa8c50.
2021-04-01 17:32:40 +02:00
Timm Bäder 1ea9fa8c50 [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
2021-04-01 17:25:23 +02:00
Timm Bäder 5018e15fdf [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
2021-03-31 16:44:19 +02:00
Sam McCall 128ce70eef [CodeCompletion] Avoid spurious signature help for init-list args
Somewhat surprisingly, signature help is emitted as a side-effect of
computing the expected type of a function argument.
The reason is that both actions require enumerating the possible
function signatures and running partial overload resolution, and doing
this twice would be wasteful and complicated.

Change #1: document this, it's subtle :-)

However, sometimes we need to compute the expected type without having
reached the code completion cursor yet - in particular to allow
completion of designators.
eb4ab3358c did this but introduced a
regression - it emits signature help in the wrong location as a side-effect.

Change #2: only emit signature help if the code completion cursor was reached.

Currently there is PP.isCodeCompletionReached(), but we can't use it
because it's set *after* running code completion.
It'd be nice to set this implicitly when the completion token is lexed,
but ConsumeCodeCompletionToken() makes this complicated.

Change #3: call cutOffParsing() *first* when seeing a completion token.

After this, the fact that the Sema::Produce*SignatureHelp() functions
are even more confusing, as they only sometimes do that.
I don't want to rename them in this patch as it's another large
mechanical change, but we should soon.

Change #4: prepare to rename ProduceSignatureHelp() to GuessArgumentType() etc.

Differential Revision: https://reviews.llvm.org/D98488
2021-03-16 12:46:40 +01:00
Anton Zabaznov 840643bbe1 [OpenCL] Refactor diagnostic for OpenCL extension/feature
There is no need to check for enabled pragma for core or optional core features,
thus this check is removed

Reviewed By: Anastasia

Differential Revision: https://reviews.llvm.org/D97058
2021-03-12 11:43:53 +03:00
Timm Bäder 64d06ed9c9 [clang][parse][NFC] Remove dead ProhibitAttributes() call
GNU-style attribute in enum bodies are allowed (and used by several
tests), and this call to ProhibitAttributes() was dead code.

Differential Revision: https://reviews.llvm.org/D97271
2021-02-23 13:54:35 +01:00
Anton Zabaznov a5b627aa4f [OpenCL] Introduce new language options for OpenCL keywords.
OpenCL keywords 'pipe' and 'generic' are unconditionally
supported for OpenCL C 2.0 or in OpenCL C++ mode. In OpenCL C 3.0
these keywords are available if corresponding optional core
feature is supported.

Reviewed By: Anastasia, svenvh

Differential Revision: https://reviews.llvm.org/D95778
2021-02-05 11:18:48 +03:00
Nico Weber 764a7a2155 clang: Fix static_assert in a few contexts in microsoft mode
Follow-up to D17444. Fixes PR48904. See bug for details.

Differential Revision: https://reviews.llvm.org/D95559
2021-01-27 18:15:25 -05:00
Aaron Ballman 9f2c7effd7 Parse different attribute syntaxes in arbitrary order
In Clang today, we parse the different attribute syntaxes
(__attribute__, __declspec, and [[]]) in a fairly rigid order. This
leads to confusion for users when they guess the order incorrectly,
and leads to bug reports like PR24559 or necessitates changes like
D94788.

This patch adds a helper function to allow us to more easily parse
attributes in arbitrary order, and then updates all of the places
where we would parse two or more different syntaxes in a rigid order to
use the helper method. The patch does not attempt to handle Microsoft
attributes ([]) because those are ambiguous with other code constructs
and we don't have any attributes that use the syntax.
2021-01-27 15:30:15 -05:00
Anastasia Stulova 4fde2b6a0c [OpenCL] Add clang extension for function pointers.
The new clang internal extension '__cl_clang_function_pointers'
allows use of function pointers and other features that have
the same functionality:
- Use of member function pointers;
- Unrestricted use of references to functions;
- Virtual member functions.

This not a vendor extension and therefore it doesn't require any
special target support. Exposing this functionality fully
will require vendor or Khronos extension.

Tags: #clang

Differential Revision: https://reviews.llvm.org/D94021
2021-01-06 20:39:57 +00:00
Nigel Perks 27ea7d0a6e Fix inconsistent availability attribute message string literal check.
Function Parser::ParseAvailabilityAttribute checks that the message string of
an availability attribute is not a wide string literal. Test case
clang/test/Parser/attr-availability.c specifies that a string literal is
expected.

The code checked that the first token in a string concatenation is a string
literal, and then that the concatenated string consists of 1-byte characters.
On a target where wide character is 1 byte, a string concatenation "a" L"b"
passes both those checks, but L"b" alone is rejected. More generally, "a" u8"b"
passes the checks, but u8"b" alone is rejected.

So check isAscii() instead of character size.
2020-12-08 12:33:59 -05:00
Erik Pilkington 9cd2413f1c [clang] Add a new nullability annotation for swift async: _Nullable_result
_Nullable_result generally like _Nullable, except when being imported into a
swift async method. rdar://70106409

Differential revision: https://reviews.llvm.org/D92495
2020-12-07 17:19:20 -05:00
Erik Pilkington 090dd647d9 [Sema] Fold VLAs to constant arrays in a few more contexts
552c6c2 removed support for promoting VLAs to constant arrays when the bounds
isn't an ICE, since this can result in miscompiling a conforming program that
assumes that the array is a VLA. Promoting VLAs for fields is still supported,
since clang doesn't support VLAs in fields, so no conforming program could have
a field VLA.

This change is really disruptive, so this commit carves out two more cases
where we promote VLAs which can't miscompile a conforming program:

 - When the VLA appears in an ivar -- this seems like a corollary to the field thing
 - When the VLA has an initializer -- VLAs can't have an initializer

Differential revision: https://reviews.llvm.org/D90871
2020-12-04 10:03:23 -05:00
Thorsten 41b65f166b Convert ConstexprKind from Specifiers.h to a scoped enum; NFC 2020-11-16 14:10:19 -05:00
Thorsten 7c6412e0cc Convert TypeSpecifierSign from Specifiers.h to a scoped enum; NFC 2020-11-16 09:08:08 -05:00
faisalv e6aa06545b [NFC, Refactor] Modernize the TypeSpecifierWidth enum (Specifiers.h) to a scoped enum
Reviewed here: https://reviews.llvm.org/D91409 by Aaron.
Highlights of the review:
  - avoid an underlying type for enums
  - avoid enum bit fields (MSVC packing anomalies) and favor static_casts to unsigned bit-fields

Patch by Thorsten Schuett <schuett@gmail.com> w some minor fixes in SemaType.cpp where a couple asserts had to be repaired to deal with lack of implicit coversion to int.

Thanks Thorsten!
2020-11-15 11:13:57 -06:00
Aaron Ballman 66b876c014 Pass the source range when diagnosing an unknown attribute
This way, the whole attribute gets highlighted with diagnostics instead
of just the scope name in an attribute like [[clang::unknown]].
2020-11-13 10:29:44 -08:00
Faisal Vali e4d27932a5 [NFC, Refactor] Rename the (scoped) enum DeclaratorContext's enumerators to remove duplication
Since these are scoped enumerators, they have to be prefixed by DeclaratorContext, so lets remove Context from the name, and return some characters to the multiverse.

Patch was reviewed here: https://reviews.llvm.org/D91011

Thank you to aaron, bruno, wyatt and barry for indulging me.
2020-11-10 23:40:12 -06:00
Aaron Puchert 5dbccc6c89 Better source location for -Wignored-qualifiers on trailing return types
We collect the source location of a trailing return type in the parser,
improving the location for regular functions and providing a location
for lambdas, where previously there was none.

Fixes PR47732.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D90129
2020-10-28 23:32:57 +01:00
Haojian Wu 702529d899 [clang] Fix returning the underlying VarDecl as top-level decl for VarTemplateDecl.
Given the following VarTemplateDecl AST,

```
VarTemplateDecl col:26 X
|-TemplateTypeParmDecl typename depth 0 index 0
`-VarDecl X 'bool' cinit
  `-CXXBoolLiteralExpr 'bool' true
```

previously, we returned the VarDecl as the top-level decl, which was not
correct, the top-level decl should be VarTemplateDecl.

Differential Revision: https://reviews.llvm.org/D89098
2020-10-12 10:46:18 +02:00
Aaron Ballman 538762fef0 Better diagnostics for anonymous bit-fields with attributes or an initializer.
The current C++ grammar allows an anonymous bit-field with an attribute,
but this is ambiguous (the attribute in that case could appertain to the
type instead of the bit-field). The current thinking in the Core Working
Group is that it's better to disallow attributes in that position at the
grammar level so that the ambiguity resolves in favor of applying to the
type.

During discussions about the behavior of the attribute, the Core Working
Group also felt it was better to disallow anonymous bit-fields from
specifying a default member initializer.

This implements both sets of related grammar changes.
2020-09-29 16:32:20 -04:00
Aaron Ballman de55ebe3bb Typo fix; NFC 2020-09-27 08:30:41 -04:00
Richard Smith 8c98c88034 PR47176: Don't read from an inactive union member if a friend function
has default arguments and an exception specification.
2020-09-24 19:02:27 -07:00
Saleem Abdulrasool 296d8832a3 Sema: add support for `__attribute__((__swift_newtype__))`
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
2020-09-24 15:17:35 +00:00
Richard Smith 0e00a95b4f Add new warning for compound punctuation tokens that are split across macro expansions or split by whitespace.
For example:

    #define FOO(x) (x)
    FOO({});

... forms a statement-expression after macro expansion. This warning
applies to '({' and '})' delimiting statement-expressions, '[[' and ']]'
delimiting attributes, and '::*' introducing a pointer-to-member.

The warning for forming these compound tokens across macro expansions
(or across files!) is enabled by default; the warning for whitespace
within the tokens is not, but is included in -Wall.

Differential Revision: https://reviews.llvm.org/D86751
2020-08-28 13:35:50 -07:00
Richard Smith 23d6525cbd Don't form a 'context-independent expr' reference to a member during
name annotation.

Instead, defer forming the member access expression or DeclRefExpr until
we build the use of ClassifyName's result. Just build an
UnresolvedLookupExpr to track the LookupResult until we're ready to
consume it.

This also reverts commit 2f7269b677 (other
than its testcase). That change was an attempted workaround for the same
problem.
2020-07-27 19:38:22 -07:00
lh123 83fae3f762 [CodeComplete] Add code completion after function equals
Summary:
Provide `default` and `delete` completion after the function equals.

Reviewers: kadircet, sammccall

Tags: #clang

Differential Revision: https://reviews.llvm.org/D82548
2020-07-01 12:51:25 +08:00
Richard Smith 4f5f6c1b83 Move late-parsed class member attribute handling adjacent to all the
other late-parsed class component handling.

No functionality change intended.
2020-06-23 15:43:11 -07:00
Erich Keane 113b0d7d0b PR46255: Fix field diagnostics for C records with anonymous members.
The ParseStructUnionBody function was separately keeping track of the
field decls for historical reasons, however the "ActOn" functions add
the field to the RecordDecl anyway.

The "ParseStructDeclaration" function, which handles parsing fields
didn't have a way of handling what happens on an anonymous field, and
changing it would alter a large amount of objc code, so I chose instead
to implement this by just filling the FieldDecls vector with the actual
FieldDecls that were successfully added to the recorddecl .
2020-06-09 12:27:44 -07:00
Ties Stuij ecd682bbf5 [ARM] Add __bf16 as new Bfloat16 C Type
Summary:
This patch upstreams support for a new storage only bfloat16 C type.
This type is used to implement primitive support for bfloat16 data, in
line with the Bfloat16 extension of the Armv8.6-a architecture, as
detailed here:

https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/arm-architecture-developments-armv8-6-a

The bfloat type, and its properties are specified in the Arm Architecture
Reference Manual:

https://developer.arm.com/docs/ddi0487/latest/arm-architecture-reference-manual-armv8-for-armv8-a-architecture-profile

In detail this patch:
- introduces an opaque, storage-only C-type __bf16, which introduces a new bfloat IR type.

This is part of a patch series, starting with command-line and Bfloat16
assembly support. The subsequent patches will upstream intrinsics
support for BFloat16, followed by Matrix Multiplication and the
remaining Virtualization features of the armv8.6-a architecture.

The following people contributed to this patch:
- Luke Cheeseman
- Momchil Velikov
- Alexandros Lamprineas
- Luke Geeson
- Simon Tatham
- Ties Stuij

Reviewers: SjoerdMeijer, rjmccall, rsmith, liutianle, RKSimon, craig.topper, jfb, LukeGeeson, fpetrogalli

Reviewed By: SjoerdMeijer

Subscribers: labrinea, majnemer, asmith, dexonsmith, kristof.beyls, arphaman, danielkiss, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D76077
2020-06-05 10:32:43 +01:00
Richard Smith 8fc12b8698 Enforce the C++11 anonymous enum bitfields check even for
Objective-C++11 and under MS extensions.

This matches the MSVC behavior, and means that Objective-C behaves as a
set of extensions to the base language, rather than replacing the base
language rule with a different one.
2020-05-10 14:03:50 -07:00
Richard Smith d6425e2c14 Properly implement 'enum class' parsing.
The 'class' or 'struct' keyword is only permitted as part of either an
enum definition or a standalone opaque-enum-declaration, not as part of
an elaborated type specifier. We previously failed to diagnose this, and
generally didn't properly implement the restrictions on elaborated type
specifiers for enumeration types.

In passing, also fixed incorrect parsing for enum-bases, which we
previously parsed as a type-name, but are actually a type-specifier-seq.
This matters for cases like 'enum E : int *p;', which is valid as a
Microsoft extension.

Plus some minor parse diagnostic improvements.

Bumped the recently-added ExtWarn for 'enum E : int x;' to be
DefaultError; this is not an intentional extension, so producing an
error by default seems appropriate, but the warning flag to disable it
may still be useful for code written against old Clang. The same
treatment is given here to the diagnostic for 'enum class E x;', which
we similarly have incorrectly accepted for many years. These diagnostics
continue to be suppressed under -fms-extensions and when compiling
Objective-C code. We will need to decide separately whether Objective-C
should follow the C++ rules or the (older) MSVC rules.
2020-05-10 13:21:04 -07:00