Commit Graph

550 Commits

Author SHA1 Message Date
Sam McCall 2a92efd0a2 [CodeComplete] drop unused Scope param. NFC 2022-01-04 12:36:27 +01:00
Sam McCall 92417eaf33 [CodeCompletion] Signature help for braced constructor calls
Implementation is based on the "expected type" as used for
designated-initializers in braced init lists. This means it can deduce the type
in some cases where it's not written:

  void foo(Widget);
  foo({ /*help here*/ });

Only basic constructor calls are in scope of this patch, excluded are:
 - aggregate initialization (no help is offered for aggregates)
 - initializer_list initialization (no help is offered for these constructors)

Fixes https://github.com/clangd/clangd/issues/306

Differential Revision: https://reviews.llvm.org/D116317
2022-01-03 20:14:59 +01:00
Sam McCall cd45e8c7bc [CodeCompletion] Signature help for template argument lists
Provide signature while typing template arguments: Foo< ^here >
Here the parameters are e.g. "typename x", and the result type is e.g.
"struct" (class template) or "int" (variable template) or "bool (std::string)"
(function template).

Multiple overloads are possible when a template name is used for several
overloaded function templates.

Fixes https://github.com/clangd/clangd/issues/299

Differential Revision: https://reviews.llvm.org/D116352
2022-01-03 16:28:16 +01:00
Aaron Ballman 6c75ab5f66 Introduce _BitInt, deprecate _ExtInt
WG14 adopted the _ExtInt feature from Clang for C23, but renamed the
type to be _BitInt. This patch does the vast majority of the work to
rename _ExtInt to _BitInt, which accounts for most of its size. The new
type is exposed in older C modes and all C++ modes as a conforming
extension. However, there are functional changes worth calling out:

* Deprecates _ExtInt with a fix-it to help users migrate to _BitInt.
* Updates the mangling for the type.
* Updates the documentation and adds a release note to warn users what
is going on.
* Adds new diagnostics for use of _BitInt to call out when it's used as
a Clang extension or as a pre-C23 compatibility concern.
* Adds new tests for the new diagnostic behaviors.

I want to call out the ABI break specifically. We do not believe that
this break will cause a significant imposition for early adopters of
the feature, and so this is being done as a full break. If it turns out
there are critical uses where recompilation is not an option for some
reason, we can consider using ABI tags to ease the transition.
2021-12-06 12:52:01 -05:00
Kazu Hirata 4bd46501c3 Use llvm::any_of and llvm::none_of (NFC) 2021-10-24 17:35:33 -07:00
Corentin Jabot ff013b6100 Extend init-statement to allow alias-declaration
Implement P2360R0 in C++23 mode and as an extension in older
languages mode.
2021-10-08 07:13:45 -04:00
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
Corentin Jabot 977bdf6f44 Make simple requirements starting with requires ill-formed in in requirement body
This patch implements P2092

Simple requirements in requirement body shall not start with requires.
A warning was already in place so we just turn this warning into an error.

In addition, we add tests to make sure typename is optional in
requirement-parameter-list as per the same paper.
2021-08-03 07:42:29 -04:00
serge-sans-paille a0d05ed848 Handle interactions between reserved identifier and user-defined suffixes
According to https://eel.is/c++draft/over.literal

> double operator""_Bq(long double);  // OK: does not use the reserved identifier _­Bq ([lex.name])
> double operator"" _Bq(long double); // ill-formed, no diagnostic required: uses the reserved identifier _­Bq ([lex.name])

Obey that rule by keeping track of the operator literal name status wrt. leading whitespace.

Fix: https://bugs.llvm.org/show_bug.cgi?id=50644

Differential Revision: https://reviews.llvm.org/D104299
2021-06-23 15:38:42 +02:00
Danila Kutenin d29f7f1a7b [clang] Fix ternary operator in the second for loop statement
Fix ternary operator in for loop argument, it was by mistake not set as CanBeForRangeDecl and led to incorrect codegen. It fixes https://bugs.llvm.org/show_bug.cgi?id=50038. I don't have commit rights. Danila Kutenin. kutdanila@yandex.ru

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D102502
2021-05-16 10:42:52 -07:00
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
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
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
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 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
Richard Smith eccc734a69 P0857R0: Parse a requires-clause after an explicit
template-parameter-list in a lambda.

This implements one of the missing parts of P0857R0. Mark it as not done
on the cxx_status page given that it's still incomplete.
2020-12-03 15:54:16 -08:00
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
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
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
Richard Smith d1446017f3 DR458: Search template parameter scopes in the right order.
C++ unqualified name lookup searches template parameter scopes
immediately after finishing searching the entity the parameters belong
to. (Eg, for a class template, you search the template parameter scope
after looking in that class template and its base classes and before
looking in the scope containing the class template.) This is complicated
by the fact that scope lookup within a template parameter scope looks in
a different sequence of places prior to reaching the end of the
declarator-id in the template declaration.

We used to approximate the proper lookup rule with a hack in the scope /
decl context walk inside name lookup. Now we instead compute the lookup
parent for each template parameter scope.

In order to get this right, we now make sure to enter a distinct Scope
for each template parameter scope, and make sure to re-enter the
enclosing class scopes properly when handling delay-parsed regions
within a class.
2020-06-23 17:14:33 -07:00
Richard Smith 02fccc26cf Revert "DR458: Search template parameter scopes in the right order."
We weren't re-entering template scopes in the right order, causing this
to break self-host with -fdelayed-template-parsing.

This reverts commit 237c2a23b6.
2020-06-16 23:53:44 -07:00
Richard Smith 237c2a23b6 DR458: Search template parameter scopes in the right order.
C++ unqualified name lookup searches template parameter scopes
immediately after finishing searching the entity the parameters belong
to. (Eg, for a class template, you search the template parameter scope
after looking in that class template and its base classes and before
looking in the scope containing the class template.) This is complicated
by the fact that scope lookup within a template parameter scope looks in
a different sequence of places prior to reaching the end of the
declarator-id in the template declaration.

We used to approximate the proper lookup rule with a hack in the scope /
decl context walk inside name lookup. Now we instead compute the lookup
parent for each template parameter scope. This gets the right answer and
as a bonus is substantially simpler and more uniform.

In order to get this right, we now make sure to enter a distinct Scope
for each template parameter scope. (The fact that we didn't before was
already a bug, but not really observable most of the time, since
template parameters can't shadow each other.)
2020-06-16 19:41:14 -07:00
Bruno Ricci a06f000326
[clang][NFC] Remove two hard-coded lists of ArrayTypeTrait and ExpressionTrait
These two were missed in 78e636b3f2.
2020-06-11 20:27:40 +01:00
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
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
Anastasia Stulova a6a237f204 [OpenCL] Added addrspace_cast operator in C++ mode.
This operator is intended for casting between
pointers to objects in different address spaces
and follows similar logic as const_cast in C++.

Tags: #clang

Differential Revision: https://reviews.llvm.org/D60193
2020-05-18 12:07:54 +01:00
Aaron Ballman 6a30894391 C++2a -> C++20 in some identifiers; NFC. 2020-04-21 15:37:19 -04:00
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 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
Haojian Wu 6f428e09fb [AST] Fix crashes on decltype(recovery-expr).
Summary: We mark these decls as invalid.

Reviewers: sammccall

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D77037
2020-03-30 14:56:33 +02:00
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 88c7ffaf94 Form invalid template-id annotations when parsing a construct that is
required to be a template-id but names an undeclared identifier.
2020-03-27 20:27:42 -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
Richard Smith 502915c619 PR45142: 'template ~X<T>' is ill-formed; reject it rather than crashing. 2020-03-23 15:07:06 -07:00
Haojian Wu 0dd0b1017c [Parser] Avoid spurious 'missing template' error in presence of typos.
Suppress those diagnostics if lhs of a member expression contains
errors. Typo correction produces dependent expressions even in
non-template code, that led to spurious diagnostics before.

previous:
    /tmp/t.cpp:6:17: error: use 'template' keyword to treat 'f' as a dependent template name
    auto a = bilder.f<int>();
                    ^
                    template
    /tmp/t.cpp:6:10: error: use of undeclared identifier 'bilder'; did you mean 'builder'?
    auto a = bilder.f<int>();
             ^~~~~~
             builder

vs now:

    /tmp/t.cpp:6:10: error: use of undeclared identifier 'bilder'; did you mean 'builder'?
    auto a = bilder.f<int>();
             ^~~~~~
             builder

Original patch from Ilya.

Reviewers: sammccall

Reviewed By: sammccall

Tags: #clang

Differential Revision: https://reviews.llvm.org/D65592
2020-03-19 16:15:27 +01:00
Jim Lin 466f8843f5 [NFC] Remove trailing space
sed -Ei 's/[[:space:]]+$//' include/**/*.{def,h,td} lib/**/*.{cpp,h,td}
2020-02-18 10:49:13 +08:00
Saar Raz 271e495399 [Concepts] Add missing TPA commit to requires expression parsing
If an error had occurred when annotating a scope spec during the tentative parse
for a type-requirement, we would not revert nor commit the tentative parse, triggerring
an assertion failure.

Commit the TPA in this case and then do error recovery.
2020-02-12 16:26:34 +02:00
Benjamin Kramer adcd026838 Make llvm::StringRef to std::string conversions explicit.
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.

This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.

This doesn't actually modify StringRef yet, I'll do that in a follow-up.
2020-01-28 23:25:25 +01:00
Kadir Cetinkaya 42e9478e0b
[clang][CodeComplete] Support for designated initializers
Reviewers: sammccall

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D73271
2020-01-28 16:34:15 +01:00
Saar Raz 5043962dd3 [Concepts] Fix parsing of scope specifier in compound-requirements, add more tests for scope specifiers in type-constraints
The code for parsing of type-constraints in compound-requirements was not adapted for the new TryAnnotateTypeConstraint which
caused compound-requirements with scope specifiers to ignore them.

Also add regression tests for scope specifiers in type-constraints in more contexts.
2020-01-26 20:46:53 +02:00
Richard Smith 04f131da0b DR1753: Don't permit x.NS::~T() as a pseudo-destructor name.
When used as qualified names, pseudo-destructors are always named as if
they were members of the type, never as members of the namespace
enclosing the type.
2020-01-24 18:53:50 -08:00
Saar Raz a0f50d7316 [Concepts] Requires Expressions
Implement support for C++2a requires-expressions.

Re-commit after compilation failure on some platforms due to alignment issues with PointerIntPair.

Differential Revision: https://reviews.llvm.org/D50360
2020-01-19 00:23:26 +02:00
Saar Raz baa84d8cde Revert "[Concepts] Requires Expressions"
This reverts commit 0279318997.

There have been some failing tests on some platforms, reverting while investigating.
2020-01-18 14:58:01 +02:00
Saar Raz 0279318997 [Concepts] Requires Expressions
Implement support for C++2a requires-expressions.

Differential Revision: https://reviews.llvm.org/D50360
2020-01-18 09:15:36 +02:00