Commit Graph

1459 Commits

Author SHA1 Message Date
Aaron Ballman 5ad15f4d1c Require commas between double square bracket attributes.
Clang currently has a bug where it allows you to write [[foo bar]] and
both attributes are silently accepted. This patch corrects the comma
parsing rules for such attributes and handles the test case fallout, as
a few tests were accidentally doing this.
2021-04-13 06:43:01 -04:00
Artem Belevich 38cf112a6b Allow applying attributes to subset of allowed subjects.
Differential Revision: https://reviews.llvm.org/D100136
2021-04-12 09:33:33 -07:00
Aaron Ballman 241d42c382 Speculative fix for failing build bot.
This attempts to resolve an issue found by http://45.33.8.238/macm1/6821/step_6.txt
2021-04-04 10:58:56 -04:00
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 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
Marek Kurdej a99b8ae390 [clang] [PR49736] [C++2b] Correctly reject lambdas with requires clause and no parameter list
This fixes http://llvm.org/PR49736 caused by implementing http://wg21.link/P1102 (https://reviews.llvm.org/rG0620e6f4b76a9725dbd82454d58c5a68a7e47074), by correctly allowing requires-clause only:
1) directly after template-parameter-list
2) after lambda-specifiers iff parameter-declaration-clause is present (2nd kind of lambda-declarator)

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D99489
2021-03-30 13:53:55 +02:00
Marek Kurdej 0620e6f4b7 [clang] [C++2b] [P1102] Accept lambdas without parameter list ().
As an extension, accept such lambdas in previous standards with a warning.

* http://eel.is/c++draft/expr.prim.lambda
* http://wg21.link/P1102

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D98433
2021-03-24 14:42:27 +01:00
Aaron Ballman fa4e72971e Automate common diagnostic checking for statement attributes
Clang currently automates a fair amount of diagnostic checking for
declaration attributes based on the declarations in Attr.td. It checks
for things like subject appertainment, number of arguments, language
options, etc. This patch uses the same machinery to perform diagnostic
checking on statement attributes.
2021-03-19 08:35:38 -04:00
Richard Smith a875721d8a PR49585: Emit the jump destination for a for loop 'continue' from within the scope of the condition variable.
The condition variable is in scope in the loop increment, so we need to
emit the jump destination from wthin the scope of the condition
variable.

For GCC compatibility (and compatibility with real-world 'FOR_EACH'
macros), 'continue' is permitted in a statement expression within the
condition of a for loop, though, so there are two cases here:

* If the for loop has no condition variable, we can emit the jump
  destination before emitting the condition.

* If the for loop has a condition variable, we must defer emitting the
  jump destination until after emitting the variable. We diagnose a
  'continue' appearing in the initializer of the condition variable,
  because it would jump past the initializer into the scope of that
  variable.

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D98816
2021-03-17 16:24:04 -07:00
Aaron Ballman ecfa874531 Update diagnostic groups for pre-compat warnings
As a follow-up to D95691, add new diagnostic groups named
pre-c++N-compat to replace the old diagnostic groups with the standards
listed out explicitly. The old group names are retained for backwards
compatibility.
2021-03-17 07:52:34 -04:00
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
Matheus Izvekov 71e6e82746 [clang] Fix constrained decltype(auto) deduction
Prior to this fix, constrained decltype(auto) behaves exactly the same
as constrained regular auto.
This fixes it so it deduces like decltype(auto).

Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D98087
2021-03-05 18:20:09 -08:00
Aaron Ballman b2bc0a3254 Implement P2173 for attributes on lambdas
https://wg21.link/P2173 is making its way through WG21 currently and
has not been formally adopted yet. This feature provides very useful
functionality in that you can specify attributes on the various
function *declarations* generated by a lambda expression, where the
current C++ grammar only allows attributes which apply to the various
function *types* so generated.

This patch implements P2173 on the assumption that it will be adopted
by WG21 with this syntax for C++23.
2021-03-03 10:05:39 -05:00
Aaron Ballman 8da090381d Improve static_assert/_Static_assert diagnostics
Our diagnostics relating to static assertions were a bit confused. For
instance, when in MS compatibility mode in C (where we accept
static_assert even without including <assert.h>), we would fail
to warn the user that they were using the wrong spelling (even in
pedantic mode), we were missing a compatibility warning about using
_Static_assert in earlier standards modes, diagnostics for the optional
message were not reflected in C as they were in C++, etc.
2021-03-03 08:48:27 -05:00
Valeriy Savchenko 81a9707723 [Attr] Apply GNU-style attributes to expression statements
Before this commit, expression statements could not be annotated
with statement attributes.  Whenever parser found attribute, it
unconditionally assumed that it was followed by a declaration.
This not only doesn't allow expression attributes to have attributes,
but also produces spurious error diagnostics.

In order to maintain all previously compiled code, we still assume
that GNU attributes are followed by declarations unless ALL of those
are statement attributes.  And even in this case we are not forcing
the parser to think that it should parse a statement, but rather
let it proceed as if no attributes were found.

Differential Revision: https://reviews.llvm.org/D93630
2021-02-11 16:44:41 +03:00
einvbri 9083d0a40d Revert "[Sema] Fix -Warray-bounds false negative when casting an out-of-bounds array item"
This reverts commit e48f444751.

thakis noticed false reports, so reverting this change for now until
those can be sorted out.

See https://reviews.llvm.org/D71714
2021-02-08 06:38:31 -06:00
Aaron Ballman 45ccfd9c9d Treat opencl_unroll_hint subject errors as semantic rather than parse errors
The attribute definition claimed the attribute was inheritable (which
only applies to declaration attributes) and not a statement attribute.
Further, it treats subject appertainment errors as being parse errors
rather than semantic errors, which leads to us accepting invalid code.
For instance, we currently fail to reject:

void foo() {
  int i = 1000;
  __attribute__((nomerge, opencl_unroll_hint(8)))
  if (i) { foo(); }
}

This addresses the issues by clarifying that opencl_unroll_hint is a
statement attribute and handles its appertainment checks in the
semantic layer instead of the parsing layer. This changes the output of
the diagnostic text to be more consistent with other appertainment
errors.
2021-02-05 07:20:41 -05:00
Ilya Mirsky e48f444751 [Sema] Fix -Warray-bounds false negative when casting an out-of-bounds array item
Patch by Ilya Mirsky!

Fixes: http://llvm.org/PR44343

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D71714
2021-02-03 07:50:50 -06:00
Aaron Ballman 5d3dca24aa Ignore unknown attribute warnings in this test
We're testing the parsing behavior, not the actual attributes used, and
the attribute name cannot be elided for __declspec attributes.
2021-01-27 15:45:35 -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
Douglas Yung be68c9222b [NFC] Add -std=c11 to attr-availability.c
This test will fail with any toolchains that don't default to C11.

Adding this switch to the clang invocation in the test fixes the issue.

Patch by Justice Adams!

Reviewed By: dyung

Differential Revision: https://reviews.llvm.org/D94829
2021-01-15 21:05:49 -08:00
Jan Svoboda 7ab803095a [clang][cli] Remove -f[no-]trapping-math from -cc1 command line
This patch removes the -f[no-]trapping-math flags from the -cc1 command line. These flags are ignored in the command line parser and their semantics is fully handled by -ffp-exception-mode.

This patch does not remove -f[no-]trapping-math from the driver command line. The driver flags are being used and do affect compilation.

Reviewed By: dexonsmith, SjoerdMeijer

Differential Revision: https://reviews.llvm.org/D93395
2021-01-12 10:00:23 +01:00
David Sherwood 38d18d9353 [SVE] Add support to vectorize_width loop pragma for scalable vectors
This patch adds support for two new variants of the vectorize_width
pragma:

1. vectorize_width(X[, fixed|scalable]) where an optional second
parameter is passed to the vectorize_width pragma, which indicates if
the user wishes to use fixed width or scalable vectorization. For
example the user can now write something like:

  #pragma clang loop vectorize_width(4, fixed)
or
  #pragma clang loop vectorize_width(4, scalable)

In the absence of a second parameter it is assumed the user wants
fixed width vectorization, in order to maintain compatibility with
existing code.
2. vectorize_width(fixed|scalable) where the width is left unspecified,
but the user hints what type of vectorization they prefer, either
fixed width or scalable.

I have implemented this by making use of the LLVM loop hint attribute:

  llvm.loop.vectorize.scalable.enable

Tests were added to

  clang/test/CodeGenCXX/pragma-loop.cpp

for both the 'fixed' and 'scalable' optional parameter.

See this thread for context: http://lists.llvm.org/pipermail/cfe-dev/2020-November/067262.html

Differential Revision: https://reviews.llvm.org/D89031
2021-01-08 11:37:27 +00:00
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
Fangrui Song fd739804e0 [test] Add {{.*}} to make ELF tests immune to dso_local/dso_preemptable/(none) differences
For a default visibility external linkage definition, dso_local is set for ELF
-fno-pic/-fpie and COFF and Mach-O. Since default clang -cc1 for ELF is similar
to -fpic ("PIC Level" is not set), this nuance causes unneeded binary format differences.

To make emitted IR similar, ELF -cc1 -fpic will default to -fno-semantic-interposition,
which sets dso_local for default visibility external linkage definitions.

To make this flip smooth and enable future (dso_local as definition default),
this patch replaces (function) `define ` with `define{{.*}} `,
(variable/constant/alias) `= ` with `={{.*}} `, or inserts appropriate `{{.*}} `.
2020-12-31 00:27:11 -08:00
Shivanshu Goyal e53b9f733a Print source location in the error message when parens are missing around sizeof typename and the expression is inside macro expansion
Given the following code:

```
void Foo(int);

void Baz()
{
	Bar(sizeof int);
}
```

The error message which is printed today is this:
```
error: expected parentheses around type name in sizeof expression
```

There is no source location printed whatsoever, so fixing a compile break like this becomes extremely hard in a large codebase.

My change improves the error message. But it doesn't output a FixItHint because I wasn't able to figure out how to get the locations for left and right parens. So any tips would be appreciated.

```
<source>:7:6: error: expected parentheses around type name in sizeof expression
        Bar(sizeof int);
            ^
```

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D91129
2020-12-16 12:03:31 -08:00
Aaron Ballman ef40d5233b Adding a test case that I accidentally dropped from 27ea7d0a6e 2020-12-15 14:56:44 -05:00
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
Haojian Wu b1444edbf4 [AST] Build recovery expression by default for all language.
The dependency mechanism for C has been implemented, and we have rolled out
this to all internal users, didn't see crashy issues, we consider it is stable
enough.

Differential Revision: https://reviews.llvm.org/D89046
2020-11-23 11:08:28 +01:00
Anatoliy Tomilov e7c7a19826 [Frontend] Treat .cuh files as CUDA source files
to synchronize with tools/clang-format/git-clang-format

tra: Keeping them in sync does have a minor benefit of not raising a question why the two maps are different.

Differential Revision: https://reviews.llvm.org/D91034
2020-11-12 11:42:53 -08:00
Serge Pavlov 6021cbea4d Add option 'exceptions' to pragma clang fp
Pragma 'clang fp' is extended to support a new option, 'exceptions'. It
allows to specify floating point exception behavior more flexibly.

Differential Revision: https://reviews.llvm.org/D89849
2020-10-31 17:36:12 +07:00
Melanie Blower 71bf9f07d5 [clang] add fexperimental-strict-floating-point to test cases that fail on arm and aarch not sure this will work due to commit rG13bfd89c4962 2020-10-30 07:30:06 -07:00
Melanie Blower 13bfd89c49 [clang][FPEnv] Diagnose Strict FP pragmas if target does not support StrictFP
Reviewers: sepavloff, kpn, aaron.ballman

Differential Revision: https://reviews.llvm.org/D90316
2020-10-30 06:11:25 -07:00
Tyker d3205bbca3 [Annotation] Allows annotation to carry some additional constant arguments.
This allows using annotation in a much more contexts than it currently has.
especially when annotation with template or constexpr.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D88645
2020-10-26 10:50:05 +01:00
Melanie Blower 576d436c82 Correct LIT test failure detected on buildbot after mibintc committed rG2e204e23911b: [clang] Enable support for #pragma STDC FENV_ACCESS D87528 2020-10-25 08:10:34 -07:00
Melanie Blower 2e204e2391 [clang] Enable support for #pragma STDC FENV_ACCESS
Reviewers: rjmccall, rsmith, sepavloff

Differential Revision: https://reviews.llvm.org/D87528
2020-10-25 06:46:25 -07:00
Hubert Tong 126094485a [PowerPC][AIX] Make `__vector [un]signed long` an error
The semantics associated with `__vector [un]signed long` are neither
consistently specified nor consistently implemented.

The IBM XL compilers on AIX traditionally treated these as deprecated
aliases for the corresponding `__vector int` type in both 32-bit and
64-bit modes. The newer, Clang-based, IBM XL compilers on AIX make usage
of the previously deprecated types an error. This is also consistent
with IBM XL C/C++ for Linux on Power (on little endian distributions).

In line with the above, this patch upgrades (on AIX) the deprecation of
`__vector long` to become removal.

Reviewed By: ZarkoCA

Differential Revision: https://reviews.llvm.org/D89443
2020-10-18 12:39:16 -04:00
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 15fbae8ac3 Use "default member initializer" instead of "in-class initializer" for diagnostics.
This changes some diagnostics to use terminology from the standard
rather than invented terminology, which improves consistency with other
diagnostics as well. There are no functional changes intended other
than wording and naming.
2020-09-29 15:04:23 -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
Serge Pavlov a633da5391 [FPEnv] Partially implement #pragma STDC FENV_ROUND
This change implements pragma STDC FENV_ROUND, which is introduced by
the extension to standard (TS 18661-1). The pragma is implemented only
in frontend, it sets apprpriate state of FPOptions stored in Sema. Use
of these bits in constant evaluation adn/or code generator is not in the
scope of this change.

Parser issues warning on unsuppored pragma when it encounteres pragma
STDC FENV_ROUND, however it makes syntax checks and updates Sema state
as if the pragma were supported.

Primary purpose of the partial implementation is to facilitate
development of non-default floating poin environment. Previously a
developer cannot set non-default rounding mode in sources, this mades
preparing tests for say constant evaluation  substantially complicated.

Differential Revision: https://reviews.llvm.org/D86921
2020-09-04 16:47:10 +07:00
Richard Smith 113861b444 Fix -Wcompound-token-split to give the same warnings under -E
-frewrite-includes.

Remove the special-case (and highly implausible) diagnostic for a
compound token that crosses a file boundary, and instead model that case
the same as a compound token separated by whitespace, so that file
transitions and presumed file transitions behave the same way.
2020-08-31 20:59:20 -07:00
Richard Smith 0da84535b1 Remove -Wcompound-token-split-by-space from -Wall.
Use of a linebreak between the `(` and `{` in a GNU statement-expression
appears to be too common to include this warning in -Wall -- this occurs
in some Linux kernel headers, for example.
2020-08-31 20:59:19 -07:00
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
Sam McCall c286d6fdee [Parser] Suppress -Wempty-translation-unit if this is a header file
This is motivated by tooling (clangd, libclang etc) - headers without
declarations are legitimate even if they're not valid TUs.

The other use -x c-header cases (PCH/modules) are nonstandard anyway and this
warning doesn't seem necessary there either.

Differential Revision: https://reviews.llvm.org/D85789
2020-08-13 09:43:27 +02:00
Richard Smith 1cbdf932b4 PR46231: Promote diagnostic for 'template<...>;' from ExtWarn to Error.
No other compiler accepts this as an extension, not even in permissive
mode. We're not doing anyone any favors by allowing this, and it's
unlikely to be at all common, even in Clang-only code, in the wild.
2020-07-29 12:35:18 -07:00
Bruno Ricci 32db24a7f2
[clang] Provide a more specific diagnostic for a misplaced lambda capture-default.
Currently a capture-default which is not the first element in the lambda-capture
is diagnosed with a generic expected variable name or 'this' in lambda capture
list, which is true but not very helpful.

If we don't have already parsed a capture-default then a lone "&" or "=" is
likely to be a misplaced capture-default, so diagnose it as such.

Differential Revision: https://reviews.llvm.org/D83681

Reviewed By: aaron.ballman
2020-07-18 20:35:16 +01:00
Haojian Wu 1d3d9c7b58 [clang] Include type specifiers in typo correction when checking isCXXDeclarationSpecifiers.
- add more tests (the test added in 2f448467e4 is weak);
- improve the `MyTemplate<type_typo, int>();` case, with this patch, typo correction
  suggests the type decl, and no regressions found.

Differential Revision: https://reviews.llvm.org/D83025
2020-07-13 12:05:09 +02:00
Haojian Wu 8c5133f185 [clang] Fix a null-NSS-access crash in DependentNameType.
The DependentNameType must have a non-null NSS. This property could be
violated during typo correction.

Differential Revision: https://reviews.llvm.org/D82738
2020-07-02 14:58:32 +02:00
Richard Smith 4d1b7e9820 Fix a few cases that were incorrectly parsed as unary-expressions
instead of postfix-expressions, and improve error recovery for postfix
operators after unary-expressions.

This covers nullptr, __null, and some calls to type traits with special
parsing rules. We would previously not parse a postfix-expression suffix
for these expressions, so would reject expressions such as
__is_trivial(int)["foo"].

For the case where a postfix-expression suffix is *not* permitted after
a unary-expression (for example, after a new-expression or sizeof
expression), produce a diagnostic if one appears there anyway. That's
always ill-formed, but previously produced very bad diagnostics.
2020-06-29 14:33:21 -07:00
Ahsan Saghir f4c337ab85 [PowerPC] Add support for vector bool __int128 for Power10
Summary:
This patch adds support for `vector bool __int128` type for Power10.

Reviewers: #powerpc, hfinkel, lei, stefanp, amyk

Reviewed By: #powerpc, lei, amyk

Subscribers: lei, amyk, wuzish, nemanjai, shchenz, cfe-commits

Tags: #llvm, #powerpc, #clang

Differential Revision: https://reviews.llvm.org/D81816
2020-06-23 21:25:56 -05:00
Yuanfang Chen 8c6c606cdc [Clang] Add a "#pragma unroll" test case for correct error reporting
For PR46336.
2020-06-16 13:03:32 -07:00
Haojian Wu 58ea1059df [AST][RecoveryExpr] Build recovery expressions by default for C++.
Reland https://reviews.llvm.org/D76696
All known crashes have been fixed, another attemption.

We have rolled out this to all internal users for a while, didn't see
big issues, we consider it is stable enough.

Reviewed By: sammccall

Subscribers: rsmith, hubert.reinterpretcast, ebevhan, jkorous, arphaman, kadircet, usaxena95, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D78350
2020-06-12 15:21:38 +02:00
Richard Smith 56a872947a Remove improper uses of DiagnosticErrorTrap and hasErrorOccurred.
DiagnosticErrorTrap is usually inappropriate because it indicates
whether an error message was rendered in a given region (and is
therefore affected by -ferror-limit and by suppression of errors if we
see an invalid declaration).

hasErrorOccurred() is usually inappropriate because it indicates
whethere an "error:" message was displayed, regardless of whether the
message was a warning promoted to an error, and therefore depends on
things like -Werror that are usually irrelevant.

Where applicable, CodeSynthesisContexts are used to attach notes to
the first diagnostic produced in a region of code, isnstead of using an
error trap and then attaching a note to whichever diagnostic happened to
be produced last (or suppressing the note if the final diagnostic is a
disabled warning!).

This is mostly NFC.
2020-06-08 14:19:57 -07:00
Zola Bridges 60ee885990 [clang][asm goto][slh] Warn if asm goto + SLH
Summary:
Asm goto is not supported by SLH. Warn if an instance of asm goto is detected
while SLH is enabled.

Test included.

Reviewed By: jyu2

Differential Revision: https://reviews.llvm.org/D79743
2020-05-20 09:46:18 -07:00
Hans Wennborg 87b235db63 Turn -Wmax-tokens off by default
On the one hand, one might interpret the use of the max-token pragmas or
-fmax-tokens flag as an opt-in to the warning. However, in Chromium
we've found it useful to only opt in selected build configurations, even
though we have the pragmas in the code. For that reason, we think it
makes sense to turn it off by default.

Differential revision: https://reviews.llvm.org/D80014
2020-05-18 13:21:46 +02:00
Melanie Blower 7f2db99350 [PATCH] #pragma float_control should be permitted in namespace scope.
Summary: Erroneous error diagnostic observed in VS2017 <numeric> header
Also correction to propagate usesFPIntrin from template func to instantiation.

Reviewers: rjmccall, erichkeane (no feedback received)

Differential Revision: https://reviews.llvm.org/D79631
2020-05-12 06:10:19 -07:00
Florian Hahn 1065869195 [Matrix] Add matrix type to Clang.
This patch adds a matrix type to Clang as described in the draft
specification in clang/docs/MatrixSupport.rst. It introduces a new option
-fenable-matrix, which can be used to enable the matrix support.

The patch adds new MatrixType and DependentSizedMatrixType types along
with the plumbing required. Loads of and stores to pointers to matrix
values are lowered to memory operations on 1-D IR arrays. After loading,
the loaded values are cast to a vector. This ensures matrix values use
the alignment of the element type, instead of LLVM's large vector
alignment.

The operators and builtins described in the draft spec will will be added in
follow-up patches.

Reviewers: martong, rsmith, Bigcheese, anemet, dexonsmith, rjmccall, aaron.ballman

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D72281
2020-05-11 18:55:45 +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 2d3f5a62de Fix typo in enum-base disambiguation. 2020-05-10 13:39:49 -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
Richard Smith c90e198107 Fix parsing of enum-base to follow C++11 rules.
Previously we implemented non-standard disambiguation rules to
distinguish an enum-base from a bit-field but otherwise treated a :
after an elaborated-enum-specifier as introducing an enum-base. That
misparses various examples (anywhere an elaborated-type-specifier can
appear followed by a colon, such as within a ternary operator or
_Generic).

We now implement the C++11 rules, with the old cases accepted as
extensions where that seemed reasonable. These amount to:
 * an enum-base must always be accompanied by an enum definition (except
   in a standalone declaration of the form 'enum E : T;')
 * in a member-declaration, 'enum E :' always introduces an enum-base,
   never a bit-field
 * in a type-specifier (or similar context), 'enum E :' is not
   permitted; the colon means whatever else it would mean in that
   context.

Fixed underlying types for enums are also permitted in Objective-C and
under MS extensions, plus as a language extension in all other modes.
The behavior in ObjC and MS extensions modes is unchanged (but the
bit-field disambiguation is a bit better); remaining language modes
follow the C++11 rules.

Fixes PR45726, PR39979, PR19810, PR44941, and most of PR24297, plus C++
core issues 1514 and 1966.
2020-05-08 19:32:00 -07:00
Melanie Blower e5578013b1 When pragma FENV_ACCESS is ignored do not modify Sema.CurFPFeatures
Bug reported by @uabelho against reviews.llvm.org/D72841

Reviewers: rjmccall

Differential Revision: https://reviews.llvm.org/D79510
2020-05-06 13:18:59 -07:00
Melanie Blower c355bec749 Add support for #pragma clang fp reassociate(on|off)
Reviewers: rjmccall, erichkeane, sepavloff

Differential Revision: https://reviews.llvm.org/D78827
2020-05-06 08:05:44 -07:00
Melanie Blower f5360d4bb3 Reapply "Add support for #pragma float_control" with buildbot fixes
Add support for #pragma float_control

Reviewers: rjmccall, erichkeane, sepavloff

Differential Revision: https://reviews.llvm.org/D72841

This reverts commit fce82c0ed3.
2020-05-04 05:51:25 -07:00
Melanie Blower fce82c0ed3 Revert "Reapply "Add support for #pragma float_control" with improvements to"
This reverts commit 69aacaf699.
2020-05-01 10:31:09 -07:00
Melanie Blower 69aacaf699 Reapply "Add support for #pragma float_control" with improvements to
test cases
Add support for #pragma float_control

Reviewers: rjmccall, erichkeane, sepavloff

Differential Revision: https://reviews.llvm.org/D72841

This reverts commit 85dc033cac, and makes
corrections to the test cases that failed on buildbots.
2020-05-01 10:03:30 -07:00
Melanie Blower 85dc033cac Revert "Add support for #pragma float_control"
This reverts commit 4f1e9a17e9.
due to fail on buildbot, sorry for the noise
2020-05-01 06:36:58 -07:00
Melanie Blower 4f1e9a17e9 Add support for #pragma float_control
Reviewers: rjmccall, erichkeane, sepavloff

Differential Revision: https://reviews.llvm.org/D72841
2020-05-01 06:14:24 -07:00
Jian Cai fcbc613ad8 Make "#pragma clang attribute" support uninitialized attribute.
Summary:
When using -ftrivial-auto-var-init=* options to initiate automatic
variables in a file, to disable initialization on some variables,
currently we have to manually annotate the variables with uninitialized
attribute, such as

int dont_initialize_me __attribute((uninitialized));

Making pragma clang attribute to support this attribute would make
annotating variables much easier, and could be particular useful for
bisection efforts, e.g.

void use(void*);

void buggy() {
    int arr[256];
    int boom;
    float bam;
    struct { int oops; } oops;
    union { int oof; float aaaaa; } oof;

    use(&arr);
    use(&boom);
    use(&bam);
    use(&oops);
    use(&oof);
}

Reviewers: jfb, rjmccall, aaron.ballman

Reviewed By: jfb, aaron.ballman

Subscribers: aaron.ballman, george.burgess.iv, dexonsmith, MaskRay, phosek, hubert.reinterpretcast, gbiv, manojgupta, llozano, srhines, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D78693
2020-04-23 14:25:13 -07:00
Erich Keane 5f0903e9be Reland Implement _ExtInt as an extended int type specifier.
I fixed the LLDB issue, so re-applying the patch.

This reverts commit a4b88c0449.
2020-04-17 10:45:48 -07:00
Sterling Augustine a4b88c0449 Revert "Implement _ExtInt as an extended int type specifier."
This reverts commit 61ba1481e2.

I'm reverting this because it breaks the lldb build with
incomplete switch coverage warnings. I would fix it forward,
but am not familiar enough with lldb to determine the correct
fix.

lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp:3958:11: error: enumeration values 'DependentExtInt' and 'ExtInt' not handled in switch [-Werror,-Wswitch]
  switch (qual_type->getTypeClass()) {
          ^
lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp:4633:11: error: enumeration values 'DependentExtInt' and 'ExtInt' not handled in switch [-Werror,-Wswitch]
  switch (qual_type->getTypeClass()) {
          ^
lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp:4889:11: error: enumeration values 'DependentExtInt' and 'ExtInt' not handled in switch [-Werror,-Wswitch]
  switch (qual_type->getTypeClass()) {
2020-04-17 10:29:40 -07:00
Erich Keane 61ba1481e2 Implement _ExtInt as an extended int type specifier.
Introduction/Motivation:
LLVM-IR supports integers of non-power-of-2 bitwidth, in the iN syntax.
Integers of non-power-of-two aren't particularly interesting or useful
on most hardware, so much so that no language in Clang has been
motivated to expose it before.

However, in the case of FPGA hardware normal integer types where the
full bitwidth isn't used, is extremely wasteful and has severe
performance/space concerns.  Because of this, Intel has introduced this
functionality in the High Level Synthesis compiler[0]
under the name "Arbitrary Precision Integer" (ap_int for short). This
has been extremely useful and effective for our users, permitting them
to optimize their storage and operation space on an architecture where
both can be extremely expensive.

We are proposing upstreaming a more palatable version of this to the
community, in the form of this proposal and accompanying patch.  We are
proposing the syntax _ExtInt(N).  We intend to propose this to the WG14
committee[1], and the underscore-capital seems like the active direction
for a WG14 paper's acceptance.  An alternative that Richard Smith
suggested on the initial review was __int(N), however we believe that
is much less acceptable by WG14.  We considered _Int, however _Int is
used as an identifier in libstdc++ and there is no good way to fall
back to an identifier (since _Int(5) is indistinguishable from an
unnamed initializer of a template type named _Int).

[0]https://www.intel.com/content/www/us/en/software/programmable/quartus-prime/hls-compiler.html)
[1]http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2472.pdf

Differential Revision: https://reviews.llvm.org/D73967
2020-04-17 07:10:57 -07:00
Richard Smith bab6df86ae Rework how UuidAttr, CXXUuidofExpr, and GUID template arguments and constants are represented.
Summary:
Previously, we treated CXXUuidofExpr as quite a special case: it was the
only kind of expression that could be a canonical template argument, it
could be a constant lvalue base object, and so on. In addition, we
represented the UUID value as a string, whose source form we did not
preserve faithfully, and that we partially parsed in multiple different
places.

With this patch, we create an MSGuidDecl object to represent the
implicit object of type 'struct _GUID' created by a UuidAttr. Each
UuidAttr holds a pointer to its 'struct _GUID' and its original
(as-written) UUID string. A non-value-dependent CXXUuidofExpr behaves
like a DeclRefExpr denoting that MSGuidDecl object. We cache an APValue
representation of the GUID on the MSGuidDecl and use it from constant
evaluation where needed.

This allows removing a lot of the special-case logic to handle these
expressions. Unfortunately, many parts of Clang assume there are only
a couple of interesting kinds of ValueDecl, so the total amount of
special-case logic is not really reduced very much.

This fixes a few bugs and issues:
 * PR38490: we now support reading from GUID objects returned from
   __uuidof during constant evaluation.
 * Our Itanium mangling for a non-instantiation-dependent template
   argument involving __uuidof no longer depends on which CXXUuidofExpr
   template argument we happened to see first.
 * We now predeclare ::_GUID, and permit use of __uuidof without
   any header inclusion, better matching MSVC's behavior. We do not
   predefine ::__s_GUID, though; that seems like a step too far.
 * Our IR representation for GUID constants now uses the correct IR type
   wherever possible. We will still fall back to using the
      {i32, i16, i16, [8 x i8]}
   layout if a definition of struct _GUID is not available. This is not
   ideal: in principle the two layouts could have different padding.

Reviewers: rnk, jdoerfert

Subscribers: arphaman, cfe-commits, aeubanks

Tags: #clang

Differential Revision: https://reviews.llvm.org/D78171
2020-04-15 12:20:42 -07:00
Haojian Wu 625acd8f68 [Parser] Improve diagnostic and error recovery when C++ keywords are used as identifiers.
Summary:
Previously, clang emitted a less-usefull diagnostic and didnt recover
well when the keywords is used as identifier in function paramter.

```
void foo(int case, int x); // previously we drop all parameters after
`int case`.
```

Reviewers: sammccall

Reviewed By: sammccall

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D77633
2020-04-08 15:15:33 +02:00
Richard Smith 6163aa9679 PR45239: Don't deallocate TemplateIdAnnotations if they might still be
in the token stream.

Previously we deleted all template-id annotations at the end of each
top-level declaration. That doesn't work: we can do some lookahead and
form a template-id annotation, and then roll back that lookahead, parse,
and decide that we're missing a semicolon at the end of a top-level
declaration, before we reach the annotation token. In that situation,
we'd end up parsing the annotation token after deleting its associated
data, leading to various forms of badness.

We now only delete template-id annotations if the preprocessor can
assure us that there are no annotation tokens left in the token stream
(or if we're already at EOF). This lets us delete the annotation tokens
earlier in a lot of cases; we now clean them up at the end of each
statement and class member, not just after each top-level declaration.
This also permitted some simplification of the delay-parsed templates
cleanup code.
2020-04-05 23:23:20 -07:00
Richard Smith 3308732300 Fix crash if base specifier parsing hits an invalid type annotation.
Also change type annotation representation from ParsedType to TypeResult
to make it clearer to consumers that they can represent invalid types.
2020-03-30 17:21:40 -07:00
Richard Smith 499b2a8d63 PR45294: Fix handling of assumed template names looked up in the lexical
scope.

There are a few contexts in which we assume a name is a template name;
if such a context is one where we should perform an unqualified lookup,
and lookup finds nothing, we would form a dependent template name even
if the name is not dependent. This happens in particular for the lookup
of a pseudo-destructor.

In passing, rename ActOnDependentTemplateName to just ActOnTemplateName
given that we apply it for non-dependent template names too.
2020-03-27 21:07:06 -07:00
Richard Smith 0c42539df3 Improve error recovery from missing '>' in template argument list.
Produce the conventional "to match this '<'" note, so that the user
knows why we expected a '>', and properly handle '>>' in C++11 onwards.
2020-03-27 18:59:01 -07:00
Richard Smith b3f6e3d6d6 Improve recovery from invalid template-ids.
Instead of bailing out of parsing when we encounter an invalid
template-name or template arguments in a template-id, produce an
annotation token describing the invalid construct.

This avoids duplicate errors and generally allows us to recover better.
In principle we should be able to extend this to store some kinds of
invalid template-id in the AST for tooling use, but that isn't handled
as part of this change.
2020-03-27 17:11:04 -07:00
Haojian Wu 62dea6e9be Revert "[AST] Build recovery expressions by default for C++."
This reverts commit 0788acbccb.
This reverts commit c2d7a1f79cedfc9fcb518596aa839da4de0adb69:  Revert "[clangd] Add test for FindTarget+RecoveryExpr (which already works). NFC"

It causes a crash on invalid code:

class X {
  decltype(unresolved()) foo;
};
constexpr int s = sizeof(X);
2020-03-26 16:25:32 +01:00
Haojian Wu 0788acbccb [AST] Build recovery expressions by default for C++.
Update the existing tests.

Reviewers: sammccall

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D76696
2020-03-25 09:00:48 +01:00
Haojian Wu 386f95e168 [Parser] Fix the assertion crash in ActOnStartOfSwitch stmt.
Summary:
After we parse the switch condition, we don't do the type check for
type-dependent expr (e.g. TypoExpr) (in Sema::CheckSwitchCondition), then the
TypoExpr is corrected to an invalid-type expr (in Sema::MakeFullExpr) and passed
to the ActOnStartOfSwitchStmt, which triggers the assertion.

Fix https://github.com/clangd/clangd/issues/311

Reviewers: sammccall

Subscribers: ilya-biryukov, kadircet, usaxena95, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D76592
2020-03-24 15:17:04 +01:00
Richard Smith ced7617c38 PR45267: Don't reject pure-specifiers with escaped newlines in their '0' token. 2020-03-20 18:44:55 -07:00
Haojian Wu bd763e2cf7 [clang] Fix crash on visiting null nestedNameSpecifier.
Summary: Fix https://github.com/clangd/clangd/issues/293

Reviewers: sammccall

Subscribers: ilya-biryukov, kadircet, usaxena95, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D76320
2020-03-18 09:15:02 +01:00
Richard Smith 44c3a63c74 PR45063: Fix crash on invalid processing an elaborated class template-id
with an invalid scope specifier.
2020-03-13 18:53:49 -07:00
Nick Desaulniers 246398ece7 [clang][Parse] properly parse asm-qualifiers, asm inline
Summary:
The parsing of GNU C extended asm statements was a little brittle and
had a few issues:
- It was using Parse::ParseTypeQualifierListOpt to parse the `volatile`
  qualifier.  That parser is really meant for TypeQualifiers; an asm
  statement doesn't really have a type qualifier. This is still maybe
  nice to have, but not necessary. We now can check for the `volatile`
  token by properly expanding the grammer, rather than abusing
  Parse::ParseTypeQualifierListOpt.
- The parsing of `goto` was position dependent, so `asm goto volatile`
  wouldn't parse. The qualifiers should be position independent to one
  another. Now they are.
- We would warn on duplicate `volatile`, but the parse error for
  duplicate `goto` was a generic parse error and wasn't clear.
- We need to add support for the recent GNU C extension `asm inline`.
  Adding support to the parser with the above issues highlighted the
  need for this refactoring.

Link: https://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html

Reviewers: aaron.ballman

Reviewed By: aaron.ballman

Subscribers: aheejin, jfb, nathanchance, cfe-commits, echristo, efriedma, rsmith, chandlerc, craig.topper, erichkeane, jyu2, void, srhines

Tags: #clang

Differential Revision: https://reviews.llvm.org/D75563
2020-03-12 15:13:59 -07:00
Sjoerd Meijer 3d9a0445cc Recommit #2 "[Driver] Default to -fno-common for all targets"
After a first attempt to fix the test-suite failures, my first recommit
caused the same failures again. I had updated CMakeList.txt files of
tests that needed -fcommon, but it turns out that there are also
Makefiles which are used by some bots, so I've updated these Makefiles
now too.

See the original commit message for more details on this change:
0a9fc9233e
2020-03-09 19:57:03 +00:00
Sjoerd Meijer f35d112efd Revert "Recommit "[Driver] Default to -fno-common for all targets""
This reverts commit 2c36c23f34.

Still problems in the test-suite, which I really thought I had fixed...
2020-03-09 10:37:28 +00:00
Sjoerd Meijer 2c36c23f34 Recommit "[Driver] Default to -fno-common for all targets"
This includes fixes for:
- test-suite: some benchmarks need to be compiled with -fcommon, see D75557.
- compiler-rt: one test needed -fcommon, and another a change, see D75520.
2020-03-09 10:07:37 +00:00
Sjoerd Meijer 4e363563fa Revert "[Driver] Default to -fno-common for all targets"
This reverts commit 0a9fc9233e.

Going to look at the asan failures.

I find the failures in the test suite weird, because they look
like compile time test and I don't understand how that can be
failing, but will have a brief look at that too.
2020-03-03 10:00:36 +00:00
Sjoerd Meijer 0a9fc9233e [Driver] Default to -fno-common for all targets
This makes -fno-common the default for all targets because this has performance
and code-size benefits and is more language conforming for C code.
Additionally, GCC10 also defaults to -fno-common and so we get consistent
behaviour with GCC.

With this change, C code that uses tentative definitions as definitions of a
variable in multiple translation units will trigger multiple-definition linker
errors. Generally, this occurs when the use of the extern keyword is neglected
in the declaration of a variable in a header file. In some cases, no specific
translation unit provides a definition of the variable. The previous behavior
can be restored by specifying -fcommon.

As GCC has switched already, we benefit from applications already being ported
and existing documentation how to do this. For example:
- https://gcc.gnu.org/gcc-10/porting_to.html
- https://wiki.gentoo.org/wiki/Gcc_10_porting_notes/fno_common

Differential revision: https://reviews.llvm.org/D75056
2020-03-03 09:15:07 +00:00
Bill Wendling 50cac24877 Support output constraints on "asm goto"
Summary:
Clang's "asm goto" feature didn't initially support outputs constraints. That
was the same behavior as gcc's implementation. The decision by gcc not to
support outputs was based on a restriction in their IR regarding terminators.
LLVM doesn't restrict terminators from returning values (e.g. 'invoke'), so
it made sense to support this feature.

Output values are valid only on the 'fallthrough' path. If an output value's used
on an indirect branch, then it's 'poisoned'.

In theory, outputs *could* be valid on the 'indirect' paths, but it's very
difficult to guarantee that the original semantics would be retained. E.g.
because indirect labels could be used as data, we wouldn't be able to split
critical edges in situations where two 'callbr' instructions have the same
indirect label, because the indirect branch's destination would no longer be
the same.

Reviewers: jyknight, nickdesaulniers, hfinkel

Reviewed By: jyknight, nickdesaulniers

Subscribers: MaskRay, rsmith, hiraditya, llvm-commits, cfe-commits, craig.topper, rnk

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D69876
2020-02-24 18:51:29 -08:00
Michele Scandale bd5b22070b Fix TryParsePtrOperatorSeq.
The syntax rules for ptr-operator allow attributes after *, &,
&&, therefore we should be able to parse the following:

void fn() {
    void (*[[attr]] x)() = &fn;
    void (&[[attr]] y)() = fn;
    void (&&[[attr]] z)() = fn;
}
However the current logic in TryParsePtrOperatorSeq does not consider
the presence of attributes leading to unexpected parsing errors.

Moreover we should also consider _Atomic a possible qualifier that can
appear after the sequence of attribute specifiers.
2020-02-24 08:08:47 -05:00
Richard Smith 24ad121582 Add -std=c++20 flag, replace C++2a with C++20 throughout the Clang
user interface and documentation, and update __cplusplus for C++20.

WG21 considers the C++20 standard to be finished (even though it still
has some more steps to pass through in the ISO process).

The old flag names are accepted for compatibility, as usual, and we
still have lots of references to C++2a in comments and identifiers;
those can be cleaned up separately.
2020-02-18 16:16:37 -08:00
Richard Smith 0e3a487784 PR12350: Handle remaining cases permitted by CWG DR 244.
Also add extension warnings for the cases that are disallowed by the
current rules for destructor name lookup, refactor and simplify the
lookup code, and improve the diagnostic quality when lookup fails.

The special case we previously supported for converting
p->N::S<int>::~S() from naming a class template into naming a
specialization thereof is subsumed by a more general rule here (which is
also consistent with Clang's historical behavior and that of other
compilers): if we can't find a suitable S in N, also look in N::S<int>.

The extension warnings are off by default, except for a warning when
lookup for p->N::S::~T() looks for T in scope instead of in N (or N::S).
That seems sufficiently heinous to warn on by default, especially since
we can't support it for a dependent nested-name-specifier.
2020-02-07 18:40:41 -08:00
Richard Smith da3dc0011e PR44684: Look through parens and similar constructs when determining
whether a call is to a builtin.

We already had a general mechanism to do this but for some reason
weren't using it. In passing, check for the other unary operators that
can intervene in a reasonably-direct function call (we already handled
'&' but missed '*' and '+').

This reverts commit aaae6b1b61,
reinstating af80b8ccc5, with a fix to
clang-tidy.
2020-02-06 12:21:54 -08:00
Fangrui Song 2513118afa [Driver] Change -fmax-tokens $arg to -fmax-tokens=$arg
Reviewed By: hans

Differential Revision: https://reviews.llvm.org/D73937
2020-02-04 09:39:48 -08:00
Saar Raz b7ce85a130 [Concepts] Fix isDeclarationSpecifier to detect type-constraints correctly
isDeclarationSpecifiers did not handle some cases of placeholder-type-specifiers with
type-constraints, causing parsing bugs in abbreviated constructor templates.

Add comprehensive handling of type-constraints to isDeclarationSpecifier.
2020-01-31 20:08:13 +02:00
Richard Smith 5ae6554a1d PR41991: Accept attributes on defaulted and deleted friends.
Attributes are permitted on friend definitions, but we only checked for
a proper function body, not for the =default / =delete cases.
2020-01-30 17:42:17 -08:00