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502 Commits

Author SHA1 Message Date
Fangrui Song c79e6007ed Revert D119136 "[clang] Implement Change scope of lambda trailing-return-type" and its follow-up
This reverts commit 69dd89fdcb.
This reverts commit 04000c2f92.

The current states breaks libstdc++ usage (https://reviews.llvm.org/D119136#3455423).
The fixup has been reverted as it caused other valid code to be disallowed.
I think we should start from the clean state by reverting all relevant commits.
2022-04-20 10:57:12 -07:00
Corentin Jabot 04000c2f92 [clang] Implement Change scope of lambda trailing-return-type
Implement P2036R3.

Captured variables by copy (explicitely or not), are deduced
correctly at the point we know whether the lambda is mutable,
and ill-formed before that.

Up until now, the entire lambda declaration up to the start of the body would be parsed in the parent scope, such that capture would not be available to look up.

The scoping is changed to have an outer lambda scope, followed by the lambda prototype and body.

The lambda scope is necessary because there may be a template scope between the start of the lambda (to which we want to attach the captured variable) and the prototype scope.

We also need to introduce a declaration context to attach the captured variable to (and several parts of clang assume captures are handled from the call operator context), before we know the type of the call operator.

The order of operations is as follow:

* Parse the init capture in the lambda's parent scope

* Introduce a lambda scope

* Create the lambda class and call operator

* Add the init captures to the call operator context and the lambda scope. But the variables are not capured yet (because we don't know their type).
Instead, explicit  captures are stored in a temporary map that conserves the order of capture (for the purpose of having a stable order in the ast dumps).

* A flag is set on LambdaScopeInfo to indicate that we have not yet injected the captures.

* The parameters are parsed (in the parent context, as lambda mangling recurses in the parent context, we couldn't mangle a lambda that is attached to the context of a lambda whose type is not yet known).

* The lambda qualifiers are parsed, at this point We can switch (for the second time) inside the lambda context, unset the flag indicating that we have not parsed the lambda qualifiers,
record the lambda is mutable and capture the explicit variables.

* We can parse the rest of the lambda type, transform the lambda and call operator's types and also transform the call operator to a template function decl where necessary.

At this point, both captures and parameters can be injected in the body's scope. When trying to capture an implicit variable, if we are before the qualifiers of a lambda, we need to remember that the variables are still in the parent's context (rather than in the call operator's).

Reviewed By: aaron.ballman, #clang-language-wg, ChuanqiXu

Differential Revision: https://reviews.llvm.org/D119136
2022-04-15 16:50:52 +02:00
Richard Smith 836e610d93 Revert "[clang] Implement Change scope of lambda trailing-return-type"
This reverts commit c729d5be78.

This change breaks thread safety annotations on lambdas.
2022-04-13 21:34:08 -07:00
Corentin Jabot c729d5be78 [clang] Implement Change scope of lambda trailing-return-type
Implement P2036R3.

Captured variables by copy (explicitely or not), are deduced
correctly at the point we know whether the lambda is mutable,
and ill-formed before that.

Up until now, the entire lambda declaration up to the start
of the body would  be parsed in the parent scope, such that
captures would not be available to look up.

The scoping is changed to have an outer lambda scope,
followed by the lambda prototype and body.

The lambda scope is necessary because there may be a template scope
between the start of the lambda (to which we want to attach
the captured variable) and the prototype scope.

We also need to introduce a declaration context to attach the captured
variable to (and several parts of clang assume captures are handled from
the call operator context), before we know the type of the call operator.

The order of operations is as follow:

* Parse the init capture in the lambda's parent scope
* Introduce a lambda scope
* Create the lambda class and call operator
* Add the init captures to the call operator context and the lambda scope.
  But the variables are not capured yet (because we don't know their type).
  Instead, explicit  captures are stored in a temporary map that
  conserves the order of capture (for the purpose of having a stable order in the ast dumps).

* A flag is set on LambdaScopeInfo to indicate that we have not yet injected the captures.

* The parameters are parsed (in the parent context, as lambda mangling recurses in the parent context,
  we couldn't mangle a lambda that is attached to the context of a lambda whose type is not yet known).

* The lambda qualifiers are parsed, at this point,
  we can switch (for the second time) inside the lambda context,
  unset the flag indicating that we have not parsed the lambda qualifiers,
  record the lambda is mutable and capture the explicit variables.

* We can parse the rest of the lambda type, transform the lambda and call operator's types and also
  transform the call operator to a template function decl where necessary.

At this point, both captures and parameters can be injected in the body's scope.
When trying to capture an implicit variable, if we are before the qualifiers of a lambda,
we need to remember that the variables are still in the parent's context (rather than in the call operator's).

This is a recommit of adff142dc2 after a fix in d8d793f29b

Reviewed By: aaron.ballman, #clang-language-wg, ChuanqiXu

Differential Revision: https://reviews.llvm.org/D119136
2022-04-13 23:07:39 +02:00
Mehdi Amini 26eec9e9db Revert "[clang] Implement Change scope of lambda trailing-return-type"
This reverts commit adff142dc2.
This broke clang bootstrap: it made existing C++ code in LLVM invalid:

llvm/include/llvm/CodeGen/LiveInterval.h:630:53: error: captured variable 'Idx' cannot appear here
              [=](std::remove_reference_t<decltype(*Idx)> V,
                                                    ^
2022-04-13 19:35:13 +00:00
Corentin Jabot 925acfea88 [Clang] Fix html error in cxx_status.html [NFC] 2022-04-13 20:27:34 +02:00
Corentin Jabot adff142dc2 [clang] Implement Change scope of lambda trailing-return-type
Implement P2036R3.

Captured variables by copy (explicitely or not), are deduced
correctly at the point we know whether the lambda is mutable,
and ill-formed before that.

Up until now, the entire lambda declaration up to the start of the body would be parsed in the parent scope, such that capture would not be available to look up.

The scoping is changed to have an outer lambda scope, followed by the lambda prototype and body.

The lambda scope is necessary because there may be a template scope between the start of the lambda (to which we want to attach the captured variable) and the prototype scope.

We also need to introduce a declaration context to attach the captured variable to (and several parts of clang assume captures are handled from the call operator context), before we know the type of the call operator.

The order of operations is as follow:

* Parse the init capture in the lambda's parent scope

* Introduce a lambda scope

* Create the lambda class and call operator

* Add the init captures to the call operator context and the lambda scope. But the variables are not capured yet (because we don't know their type).
Instead, explicit  captures are stored in a temporary map that conserves the order of capture (for the purpose of having a stable order in the ast dumps).

* A flag is set on LambdaScopeInfo to indicate that we have not yet injected the captures.

* The parameters are parsed (in the parent context, as lambda mangling recurses in the parent context, we couldn't mangle a lambda that is attached to the context of a lambda whose type is not yet known).

* The lambda qualifiers are parsed, at this point We can switch (for the second time) inside the lambda context, unset the flag indicating that we have not parsed the lambda qualifiers,
record the lambda is mutable and capture the explicit variables.

* We can parse the rest of the lambda type, transform the lambda and call operator's types and also transform the call operator to a template function decl where necessary.

At this point, both captures and parameters can be injected in the body's scope. When trying to capture an implicit variable, if we are before the qualifiers of a lambda, we need to remember that the variables are still in the parent's context (rather than in the call operator's).

Reviewed By: aaron.ballman, #clang-language-wg, ChuanqiXu

Differential Revision: https://reviews.llvm.org/D119136
2022-04-13 20:00:03 +02:00
Nathan Sidwell 54c50336e4 [clang] Document p1703 not needed
We list p1703 as unimplemented, but it is subsumed by p1857.

Reviewed By: tbaeder

Differential Revision: https://reviews.llvm.org/D123120
2022-04-05 06:54:31 -07:00
Erich Keane 281b7eeb14 Update www_status/add test for P1972:
This seems to have been implemented/supported correctly back in Clang
10, so update the documentation and add the test from the paper.
2022-03-28 06:31:04 -07:00
Corentin Jabot 3784e8ccfb [Clang] Fix Unevaluated Lambdas
Unlike other types, when lambdas are instanciated,
they are recreated from scratch.
When an unevaluated lambdas appear in the type of a function,
parameter it is instanciated in the wrong declaration context,
as parameters are transformed before the function.

To support lambda in function parameters, we try to
compute whether they are dependant without looking at the
declaration context.

This is a short term stopgap solution to avoid clang
iceing. A better fix might be to inject some kind of
transparent declaration with correctly computed dependency
for function parameters, variable templates, etc.

Fixes https://github.com/llvm/llvm-project/issues/50376
Fixes https://github.com/llvm/llvm-project/issues/51414
Fixes https://github.com/llvm/llvm-project/issues/51416
Fixes https://github.com/llvm/llvm-project/issues/51641
Fixes https://github.com/llvm/llvm-project/issues/54296

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D121532
2022-03-25 19:16:45 +01:00
Aaron Ballman b26466d001 Update the C and C++ status pages now that Clang 14 is out 2022-03-23 07:59:52 -04:00
Corentin Jabot 683e83c56f [Clang][C++2b] P2242R3: Non-literal variables [...] in constexpr
Allow goto, labelled statements as well as `static`, `thread_local`, and
non-literal variables in `constexpr` functions.

As specified. for all of the above (except labelled statements) constant
evaluation of the construct still fails.

For `constexpr` bodies, the proposal is implemented with diagnostics as
a language extension in older language modes. For determination of
whether a lambda body satisfies the requirements for a constexpr
function, the proposal is implemented only in C++2b mode to retain the
semantics of older modes for programs conforming to them.

Reviewed By: aaron.ballman, hubert.reinterpretcast, erichkeane

Differential Revision: https://reviews.llvm.org/D111400
2022-03-22 19:51:19 +01:00
Zhihao Yuan 136b293129
[c++2b] Implement P0849R8 auto(x)
https://wg21.link/p0849

Reviewed By: aaron.ballman, erichkeane

Differential Revision: https://reviews.llvm.org/D113393
2022-02-28 19:21:08 -06:00
Richard Smith dc8f4e118d [cxx_status] Add a couple of Feb 2022 library papers that need compiler support. 2022-02-08 17:25:52 -08:00
Corentin Jabot c151225096 [C++2b] Implement multidimentional subscript operator
Implement P2128R6 in C++23 mode.

Unlike GCC's implementation, this doesn't try to recover when a user
meant to use a comma expression.

Because the syntax changes meaning in C++23, the patch is *NOT*
implemented as an extension. Instead, declaring an array with not
exactly 1 parameter is an error in older languages modes. There is an
off-by-default extension warning in C++23 mode.

Unlike the standard, we supports default arguments;

Ie, we assume, based on conversations in WG21, that the proposed
resolution to CWG2507 will be accepted.

We allow arrays OpenMP sections and C++23 multidimensional array to
coexist:

[a , b] multi dimensional array
[a : b] open mp section
[a, b: c] // error

The rest of the patch is relatively straight forward: we take care to
support an arbitrary number of arguments everywhere.
2022-02-08 12:10:47 -05:00
Corentin Jabot 3c17f3955c Add core papers adopted at the february plenary.
2 papers are added to the status page, one targeting
C++23, the other added to the batch of C++20 concept papers.
2022-02-08 09:13:04 -05:00
Chuanqi Xu bbce75e352 Update Bug report URL to Github Issues
Although we moved to Github Issues. The bug report message refers to
Bugzilla still. This patch tries to update these URLs.

Reviewed By: MaskRay, Quuxplusone, jhenderson, libunwind, libc++

Differential Revision: https://reviews.llvm.org/D116351
2022-01-06 17:33:25 +08:00
Nathan Sidwell 5fbe21a774 [clang] p2085 out-of-class comparison operator defaulting
This implements p2085, allowing out-of-class defaulting of comparison
operators, primarily so they need not be inline, IIUC intent. this was
mostly straigh forward, but required reimplementing
Sema::CheckExplicitlyDefaultedComparison, as now there's a case where
we have no a priori clue as to what class a defaulted comparison may
be for. We have to inspect the parameter types to find out. Eg:

class X { ... };
bool operator==(X, X) = default;

Thus reimplemented the parameter type checking, and added 'is this a
friend' functionality for the above case.

Reviewed By: mizvekov

Differential Revision: https://reviews.llvm.org/D104478
2021-12-16 07:22:46 -08:00
Chuanqi Xu 5653d127d7 [docs] Give the reason why the support for coroutine is partial
This helps user to know what level of support there
is (roughly) for coroutine feature.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D115778
2021-12-15 21:01:46 +08:00
Yaxun (Sam) Liu 60a085beb0 Revert "[clang] deprecate frelaxed-template-template-args, make it on by default"
This reverts commit 2d7fba5f95.

The patch was reverted because it caused regression with rocThrust
due to ambiguity of template specialization.

For details please see https://reviews.llvm.org/D109496
2021-11-02 17:02:19 -04:00
Matheus Izvekov 2d7fba5f95
[clang] deprecate frelaxed-template-template-args, make it on by default
A resolution to the ambiguity issues created by P0522, which is a DR solving
CWG 150, did not come as expected, so we are just going to accept the change,
and watch how users digest it.

For now we deprecate the flag with a warning, and make it on by default.
We don't remove the flag completely in order to give users a chance to
work around any problems by disabling it.

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

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D109496
2021-10-27 22:48:27 +02:00
Aaron Ballman acfe7d895d Update the title and encoding for the C++ status page 2021-10-21 12:14:44 -04:00
Aaron Ballman cfca2ae1f5 Update the C++ and C status pages now that Clang 13 has been released 2021-10-21 12:13:19 -04:00
Nathan Sidwell d45526e6c3 [doc][clang] correct version for p0388 implementation
The p0388 patch series took so long, the clang version was incorrect,
and I failed to realize that.
2021-10-13 04:12:07 -07:00
Nathan Sidwell 444ec0957c [clang] p0388 array list initialization overloads
This is the second part of p0388, dealing with overloads of list
initialization to incomplete array types.  It extends the handling
added in D103088 to permit incomplete arrays.  We have to record that
the conversion involved an incomplete array, and so (re-add) a bit flag
into the standard conversion sequence object.  Comparing such
conversion sequences requires knowing (a) the number of array elements
initialized and (b) whether the initialization is of an incomplete array.

This also updates the web page to indicate p0388 is implemented (there
is no feature macro).

Differential Revision: https://reviews.llvm.org/D103908
2021-10-12 07:35:21 -07:00
Richard Smith 7ac308fb8f PR52073: Fix equivalence computation for lambda-expressions.
Distinct lambda expressions are always considered non-equivalent, so two
token-for-token identical function declarations whose signatures involve
lambda-expressions declare distinct functions.
2021-10-08 13:54:01 -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
Corentin Jabot d456fed1a9 Add information about partially implemented features
Desccribe in cxx_status.html the missing parts of the partially
implemented proposals described in cxx_status.html.

Uses <details> blocks so the information appears collapsed
by default.
2021-10-07 13:07:44 -04:00
Aaron Ballman aa4f4d18e8 consteval if is now fully supported
This amends 424733c12a which accidentally
dropped the change to the status page.
2021-10-05 08:21:29 -04:00
Corentin Jabot 922863e75f Add core papers added in the October 2021 WG21 plenary 2021-10-04 14:42:13 -04:00
Corentin Jabot 7fc743ff84 Mark as P0692R1 as implemented; NFC
P0692R1 was implemented in https://reviews.llvm.org/D92024
but the status page was not updated.
2021-09-09 08:45:47 -04:00
Corentin Jabot 4e80636db7 Implement P1949
This adds the Unicode 13 data for XID_Start and XID_Continue.
The definition of valid identifier is changed in all C++ modes
as P1949 (https://wg21.link/p1949) was accepted by WG21 as a defect
report.
2021-08-18 07:33:14 -04:00
Corentin Jabot 131b4620ee Implement P1937 consteval in unevaluated contexts
In an unevaluated contexts, consteval functions should not be
immediately evaluated.
2021-08-06 10:29:28 -04:00
Corentin Jabot 3c8e94bc20 Disallow narrowing conversions to bool in noexcept specififers
Completes the support for P1401R5.
2021-08-06 10:26:39 -04:00
Aaron Ballman 80c17bb298 This feature is not in Clang 13 and only has partial support 2021-08-03 08:21:15 -04:00
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
Corentin Jabot 8747234032 Partially implement P1401R5 (Narrowing contextual conversions to bool)
Support Narrowing conversions to bool in if constexpr condition
under C++23 language mode.

Only if constexpr is implemented as the behavior of static_assert
is already conforming. Still need to work on explicit(bool) to
complete support.
2021-07-12 08:06:27 -04:00
Corentin Jabot 18c3c77849 Add papers adopted by the C++ committee in the June 2021 plenary 2021-06-28 13:45:12 -04:00
Corentin Jabot 22aa3680ea [C++20] Support for lambdas in unevaluated context
Partially implement P0315R4.

This patch allow lambda in unevaluated context.
It does not implement temp.deduct/9.
2021-06-28 09:01:56 -04:00
Matheus Izvekov ced6b204d1 [clang] Implement P2266 Simpler implicit move
This Implements [[http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2266r1.html|P2266 Simpler implicit move]].

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

Reviewed By: Quuxplusone

Differential Revision: https://reviews.llvm.org/D99005
2021-06-18 17:08:59 +02:00
Aaron Ballman 8908903eac Corrects some minor issues with the CXX status page.
1) Adds some </p> tags where they were missing.
2) Documents that C++14 is the current default language mode, not C++98
2021-06-09 13:38:41 -04:00
Nathan Sidwell c1cd743519 [clang] p1099 using-enum feature macro & web page
This completes the series implementing p1099, by adding the feature
macro and updating the web page.

Differential Revision: https://reviews.llvm.org/D102242
2021-06-09 05:40:53 -07:00
Anton Bikineev dc7ebd2cb0 [C++2b] Support size_t literals
This adds support for C++2b's z/uz suffixes for size_t literals (P0330).
2021-03-31 13:36:23 +00:00
Richard Smith ee176d2e6e [www] Color Clang 11 and Clang 12 features as green and not yellow, and
Clang 13 features as yellow not green.
2021-03-30 15:22:16 -07:00
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 d95c6d3b69 [www] Add cxx_status tracking for C++23.
Convert the list of standards to a table; it's starting to get unwieldy.
2021-02-25 14:47:43 -08:00
Yang Fan fbee4a0c79 [C++20] [P1825] More implicit moves
Implement all of P1825R0:

- implicitly movable entity can be an rvalue reference to non-volatile
    automatic object.
- operand of throw-expression can be a function or catch-clause parameter
    (support for function parameter has already been implemented).
- in the first overload resolution, the selected function no need to be
    a constructor.
- in the first overload resolution, the first parameter of the selected
    function no need to be an rvalue reference to the object's type.

This patch also removes the diagnostic `-Wreturn-std-move-in-c++11`.

Differential Revision: https://reviews.llvm.org/D88220
2021-02-16 17:24:20 -05:00
Richard Smith 727fc31a98 [cxx_status] Mark P0732R2 as only 'partial', not 'Clang 12', as some of
the changes were reverted.
2021-01-27 16:08:51 -08:00
Richard Smith 987760b463 [www] Fix background color in table cell. 2021-01-19 11:04:31 -08:00
Richard Smith b4c63ef6dd [c++20] Mark class type NTTPs as done and start defining the feature test macro. 2020-12-18 13:42:23 -08:00