Commit Graph

1601 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
Aaron Ballman 9955f14aaf [C2x] Disallow functions without prototypes/functions with identifier lists
WG14 has elected to remove support for K&R C functions in C2x. The
feature was introduced into C89 already deprecated, so after this long
of a deprecation period, the committee has made an empty parameter list
mean the same thing in C as it means in C++: the function accepts no
arguments exactly as if the function were written with (void) as the
parameter list.

This patch implements WG14 N2841 No function declarators without
prototypes (http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2841.htm)
and WG14 N2432 Remove support for function definitions with identifier
lists (http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2432.pdf).

It also adds The -fno-knr-functions command line option to opt into
this behavior in other language modes.

Differential Revision: https://reviews.llvm.org/D123955
2022-04-20 13:28:15 -04:00
Timm Bäder 33ec653055 [clang][lexer] Allow u8 character literal prefixes in C2x
Implement N2418 for C2x.

Differential Revision: https://reviews.llvm.org/D119221
2022-04-19 09:57:51 +02:00
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
PoYao Chang 50b1faf5c1 [Clang] CWG 1394: Incomplete types as parameters of deleted functions
According to CWG 1394 and C++20 [dcl.fct.def.general]p2,
Clang should not diagnose incomplete types if function body is "= delete;".
For example:
```
struct Incomplete;
Incomplete f(Incomplete) = delete; // well-formed
```

Also close https://github.com/llvm/llvm-project/issues/52802

Differential Revision: https://reviews.llvm.org/D122981
2022-04-12 11:10:10 +08:00
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
Shivam 83bde93cef
resolve typo in the manual. 2022-04-01 03:15:17 +05:30
Markus Böck e59335e891 [clang][DR] Add test for DR1227 and mark it as complete
DR: http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#1227

This DR has been implemented in Clang as far back as I could check. This patch simply adds a test and comment to mark it as complete.

Differential Revision: https://reviews.llvm.org/D122682
2022-03-30 09:25:52 +02:00
Markus Böck c1e614c8eb [clang][DR] Test and mark DR1305 as complete
DR: http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#1305

This DR has always been implemented in all clang versions as far back as I could go. This patch basically just adds a test with the needed comments to mark it as complete.

Differential Revision: https://reviews.llvm.org/D122674
2022-03-29 20:45:49 +02:00
Markus Böck 984554f846 [clang][DR] Test and mark DR1479 as complete
DR: http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#1479

Clang has implemented this DR as far back as I could go on compiler explorer (3.0). This patch simply adds a test case and needed comments for the update script to mark it as complete.

Differential Revision: https://reviews.llvm.org/D122620
2022-03-29 09:28:32 +02:00
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
Danny Mösch a749e3295d Replace links to archived mailing lists by links to Discourse forums 2022-03-23 10:10:20 -04:00
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
Vlad Serebrennikov a603f566db [clang] CWG 2354: prohibit alignas for enums
Reviewed By: aaron.ballman, erichkeane

Differential Revision: https://reviews.llvm.org/D121723
2022-03-16 15:48:18 +08:00
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
Timm Bäder 02571f86bb [clang][www] Port make_cxx_dr_status script to Python3
And run it to re-generate the cxx_dr_status.html

Differential Revision: https://reviews.llvm.org/D120313
2022-02-22 15:47:43 +01:00
Balazs Benics 5e0be95fce [analyzer][docs][NFC] Fix some broken links and some cosmetic changes
- We should report bugs to the GitHub Issues
- We should advocate using Discourse instead of the superseded cfe-dev
  mailing list.

There are a couple of other cosmetic changes such as preferring `using`
instead of `typedef` and quoting the `-analyze-function` parameter's
payload for escaping the braces.

Thanks @loic-joly-sonarsource for reporting this on Discord!

Reviewed By: NoQ, Szelethus

Differential Revision: https://reviews.llvm.org/D119245
2022-02-09 10:22:28 +01:00
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
Aaron Ballman bf7d9970ba Support the *_WIDTH macros in limits.h and stdint.h
This completes the implementation of
WG14 N2412 (http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2412.pdf),
which standardizes C on a twos complement representation for integer
types. The only work that remained there was to define the correct
macros in the standard headers, which this patch does.
2022-01-13 11:46:34 -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
Aaron Ballman 1feb8ab0d3 Update the status of N2412 in C (we do not implement large parts of it) 2021-12-06 13:14:13 -05:00
Quinn Pham c71fbdd87b [NFC] Inclusive language: Remove instances of master in URLs
[NFC] This patch fixes URLs containing "master". Old URLs were either broken or
redirecting to the new URL.

Reviewed By: #libc, ldionne, mehdi_amini

Differential Revision: https://reviews.llvm.org/D113186
2021-11-05 08:48:41 -05:00
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
Frederik Seiffert c5348355ee [www] Fix Ninja build instructions on Windows
The `clang` target used in the line below is only generated with `LLVM_ENABLE_PROJECTS=clang`.

Without this change, running `ninja clang` will fail with:
```
ninja: error: unknown target 'clang', did you mean 'clean'?
```

Reviewed By: xgupta

Differential Revision: https://reviews.llvm.org/D112257
2021-10-23 16:09:04 +05:30
Aaron Ballman 408075ec6a Add the papers that were applied to the latest C2x working draft 2021-10-21 13:38:57 -04:00
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
Erich Keane 77d200a546 Add test for DR1307, which we have already implemented.
Also regenerated cxx_dr_status.html
2021-09-24 10:24:32 -07:00
Erich Keane 8dd42ffc09 Write test for CWG1772/CWG1762/CWG1779, mark them 'done', and update
cxx_dr_status.html

I noticed that these two DRs are currently working correctly, so I
added a pair of lit tests that check the AST (which is most useful for
CWG1779, since 'dependent' is really only observable in an ast dump) to
make sure __func__ works correctly in dependent cases, and in lambda
operator().

Also noticed that CWG1762, mostly an 'example' change, works correctly,
so added a test so that it gets marked 'done' as well.

Additionally, I regenerated cxx_dr_status.html, updating it for Clang
13's release, based on the cwg_status.html from August 12, 2021.

Differential Revision: https://reviews.llvm.org/D109956
2021-09-24 10:10:38 -07:00
Aaron Ballman fe16d331d3 Add document numbers for the C99 status page.
This doesn't add all of the document numbers, but it adds a bunch of
them. Not all of the documents are available on the committee page
(they're old enough that they come from a time when the mailing was
comprised of physical pieces of paper), so some of the documents listed
are assumed to be correct based on my reading of editor's reports.
2021-09-22 13:02:25 -04:00
Aaron Ballman 101c3de39f Add information about C99 to the C status page. 2021-09-17 13:49:17 -04:00