Commit Graph

452 Commits

Author SHA1 Message Date
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
Mark de Wever 2bcda6bb28 [Sema, CodeGen] Implement [[likely]] and [[unlikely]] in SwitchStmt
This implements the likelihood attribute for the switch statement. Based on the
discussion in D85091 and D86559 it only handles the attribute when placed on
the case labels or the default labels.

It also marks the likelihood attribute as feature complete. There are more QoI
patches in the pipeline.

Differential Revision: https://reviews.llvm.org/D89210
2020-10-18 13:48:42 +02:00
Richard Smith 00d3e6c1b4 [c++17] Implement P0145R3 during constant evaluation.
Ensure that we evaluate assignment and compound-assignment
right-to-left, and array subscripting left-to-right.

Fixes PR47724.

This is a re-commit of ded79be, reverted in 37c74df, with a fix and test
for the crasher bug previously introduced.
2020-10-06 12:30:26 -07:00
Dmitri Gribenko 37c74dfe72 Revert "[c++17] Implement P0145R3 during constant evaluation."
This reverts commit ded79be635. It causes
a crash (I sent the crash reproducer directly to the author).
2020-10-06 15:49:44 +02:00
Richard Smith ded79be635 [c++17] Implement P0145R3 during constant evaluation.
Ensure that we evaluate assignment and compound-assignment
right-to-left, and array subscripting left-to-right.

Fixes PR47724.
2020-10-05 19:04:14 -07:00
Mark de Wever 08196e0b2e Implements [[likely]] and [[unlikely]] in IfStmt.
This is the initial part of the implementation of the C++20 likelihood
attributes. It handles the attributes in an if statement.

Differential Revision: https://reviews.llvm.org/D85091
2020-09-09 20:48:37 +02:00
Hubert Tong 021a333bfc [www] Turn 'Clang 10' boxes green in C++ status pages to reflect release
Summary:
The 'Clang 10' boxes should be green since Clang 10 has been released.

Reviewers: rsmith, aaron.ballman

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D78068
2020-04-14 18:38:35 -04:00
Hubert Tong dfaafbab46 [www] cxx_status: Update Reflection TS to Cologne draft
Summary:
As of the 2019 Cologne meeting, according to its minutes (N4826), N4818
is the draft of the Reflection TS.

Reviewers: rsmith, aaron.ballman

Reviewed By: aaron.ballman

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D75524
2020-03-09 14:51:11 -04:00
Hubert Tong f4076ad640 [www] cxx_status: Update title to mention C++20
Summary:
The document covers the Clang implementation status of the "upcoming
C++20 standard". Update the title to match.

Reviewers: rsmith, aaron.ballman

Reviewed By: aaron.ballman

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D75523
2020-03-09 14:51:11 -04:00
Richard Smith 6d34a87bae [cxx_status] Update -std= instructions for C++20.
We merged support for -std=c++20 to the Clang 10 branch, so -std=c++2a
is only needed in Clang 9 and earlier.
2020-02-20 11:40:09 -08:00
Richard Smith 061f3a50dd P0593R6: Pseudo-destructor expressions end object lifetimes.
This only has an observable effect on constant evaluation.
2020-02-18 18:41:03 -08:00
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 b74a381296 [cxx_status] New papers from Prague 2020 WG21 meeting. 2020-02-15 02:16:21 -08:00
Richard Smith 42efd35ba0 [cxx_status] Fix status of P1766R to not bleed into adjacent cells. 2020-02-07 11:54:48 -08:00
Richard Smith 7ae1b4a0ce Implement P1766R1: diagnose giving non-C-compatible classes a typedef name for linkage purposes.
Summary:
Due to a recent (but retroactive) C++ rule change, only sufficiently
C-compatible classes are permitted to be given a typedef name for
linkage purposes. Add an enabled-by-default warning for these cases, and
rephrase our existing error for the case where we encounter the typedef
name for linkage after we've already computed and used a wrong linkage
in terms of the new rule.

Reviewers: rjmccall

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D74103
2020-02-07 11:47:37 -08:00
Saar Raz f394d22fa8 [Concepts] Update cxx_status.html with Concepts support status
Concepts will be available with Clang 10 - update cxx_status.html to reflect
the papers that have been implemented.
2020-01-24 03:00:38 +02:00
Richard Smith b32013baec [www] Update cxx_status page to list changes on the Clang 10 branch as
"Clang 10" not "SVN".
2020-01-22 14:48:56 -08:00
Richard Smith df2e2ab07b Implement latest C++ feature test macro recommendations.
We don't yet advertise init capture packs, because I found some bugs
while testing it. We reject-valid and then crash on both of these:

template<int ...a> auto x = [...y = a] {};
template<int ...a> auto x = [y = a...] {};
2019-12-19 12:59:13 -08:00
Richard Smith f495de43bd [c++20] P1959R0: Remove support for std::*_equality. 2019-12-16 17:49:45 -08:00
Richard Smith 4b00299958 [c++20] Add deprecation warnings for the expression forms deprecated by P1120R0.
This covers:
 * usual arithmetic conversions (comparisons, arithmetic, conditionals)
   between different enumeration types
 * usual arithmetic conversions between enums and floating-point types
 * comparisons between two operands of array type

The deprecation warnings are on-by-default (in C++20 compilations); it
seems likely that these forms will become ill-formed in C++23, so
warning on them now by default seems wise.

For the first two bullets, off-by-default warnings were also added for
all the cases where we didn't already have warnings (covering language
modes prior to C++20). These warnings are in subgroups of the existing
-Wenum-conversion (except that the first case is not warned on if either
enumeration type is anonymous, consistent with our existing
-Wenum-conversion warnings).
2019-12-16 17:49:45 -08:00
Richard Smith bc633a42dd Mark the major papers for C++20 consistent comparisons as "done", and
start publishing the corresponding feature-test macro.
2019-12-15 22:20:06 -08:00
Richard Smith 357e64e952 [cxx_status] Fix paper number for "Concept auto" paper. 2019-12-14 14:53:05 -08:00
Richard Smith f7235ac1d3 [cxx_status] Re-add missing cell. 2019-12-10 19:56:07 -08:00
Richard Smith ffe612922c [c++20] Implement P1946R0: allow defaulted comparisons to take their
arguments by value.
2019-12-10 19:54:35 -08:00
Richard Smith 8e0c9e21bf [c++20] Delete defaulted comparison functions if they would invoke an
inaccessible comparison function.
2019-12-10 19:28:30 -08:00
Richard Smith 336ac7197e [cxx_status] Fix table layout. 2019-12-10 13:03:12 -08:00
Richard Smith 439cb88e26 [cxx_status] Add missed Belfast paper affecting three-way comparisons. 2019-12-10 11:49:04 -08:00
Richard Smith 5253d9138e [c++20] Determine whether a defaulted comparison should be deleted or
constexpr.
2019-12-06 16:32:48 -08:00
Richard Smith 092577e317 [cxx_status] Update with Belfast motions. 2019-11-09 03:13:21 -08:00
Stephan T. Lavavej 2e4f1e112d [www] Change URLs to HTTPS.
This changes most URLs in llvm's html files to HTTPS. Most changes were
search-and-replace with manual verification; some changes were manual.
For a few URLs, the websites were performing redirects or had changed
their anchors; I fixed those up manually. This consistently uses the
official https://wg21.link redirector. This also strips trailing
whitespace and fixes a couple of typos.

Fixes D69363.

There are a very small number of dead links for which I don't know any
replacements (they are equally dead as HTTP or HTTPS):

https://llvm.org/cmds/llvm2cpp.html
https://llvm.org/devmtg/2010-11/videos/Grosser_Polly-desktop.mp4
https://llvm.org/devmtg/2010-11/videos/Grosser_Polly-mobile.mp4
https://llvm.org/devmtg/2011-11/videos/Grosser_PollyOptimizations-desktop.mov
https://llvm.org/devmtg/2011-11/videos/Grosser_PollyOptimizations-mobile.mp4
https://llvm.org/perf/db_default/v4/nts/22463
https://polly.llvm.org/documentation/memaccess.html
2019-10-24 13:25:15 -07:00
Richard Smith 974c8b7e2f [c++20] Add rewriting from comparison operators to <=> / ==.
This adds support for rewriting <, >, <=, and >= to a normal or reversed
call to operator<=>, for rewriting != to a normal or reversed call to
operator==, and for rewriting <=> and == to reversed forms of those same
operators.

Note that this is a breaking change for various C++17 code patterns,
including some in use in LLVM. The most common patterns (where an
operator== becomes ambiguous with a reversed form of itself) are still
accepted under this patch, as an extension (with a warning). I'm hopeful
that we can get the language rules fixed before C++20 ships, and the
extension warning is aimed primarily at providing data to inform that
decision.

llvm-svn: 375306
2019-10-19 00:04:43 +00:00
Richard Smith 4a6861a7e5 [c++20] P1152R4: warn on any simple-assignment to a volatile lvalue
whose value is not ignored.

We don't warn on all the cases that are deprecated: specifically, we
choose to not warn for now if there are parentheses around the
assignment but its value is not actually used. This seems like a more
defensible rule, particularly for cases like sizeof(v = a), where the
parens are part of the operand rather than the sizeof syntax.

llvm-svn: 374135
2019-10-09 02:04:54 +00:00
Richard Smith 84ef9c6493 [c++20] Implement most of P1152R4.
Diagnose some now-deprecated uses of volatile types:
 * as function parameter types and return types
 * as the type of a structured binding declaration
 * as the type of the lvalue operand of an increment / decrement /
   compound assignment operator

This does not implement a check for the deprecation of simple
assignments whose results are used; that check requires somewhat
more complexity and will be addressed separately.

llvm-svn: 374133
2019-10-09 00:49:40 +00:00
Richard Smith 32377ad7cb [cxx_status] Note that Clang has supported std::source_location since
version 9.

llvm-svn: 374131
2019-10-08 23:39:56 +00:00
Richard Smith 69e9d84b1a Mark P0784R7 as complete and start defining its feature-test macro.
Note that this only covers the language side of this feature. (The
library side has its own feature test macro.)

llvm-svn: 373548
2019-10-03 00:39:37 +00:00
Richard Smith 9bc1c6ecc5 [cxx_status] Mark P0784R7 as partially complete.
llvm-svn: 373162
2019-09-29 07:16:13 +00:00
Richard Smith 2d2850ff09 [www] Turn 'Clang 9' boxes green in C++ status pages now Clang 9 is
released.

llvm-svn: 372415
2019-09-20 18:09:05 +00:00
Richard Smith c667cdc850 [c++20] P1331R2: Allow transient use of uninitialized objects in
constant evaluation.

llvm-svn: 372237
2019-09-18 17:37:44 +00:00
Richard Smith a6e8b685e1 [c++20] P1143R2: Add support for the C++20 'constinit' keyword.
This is mostly the same as the
[[clang::require_constant_initialization]] attribute, but has a couple
of additional syntactic and semantic restrictions.

In passing, I added a warning for the attribute form being added after
we have already seen the initialization of the variable (but before we
see the definition); that case previously slipped between the cracks and
the attribute was silently ignored.

llvm-svn: 370972
2019-09-04 20:30:37 +00:00
Richard Smith 03d2567f91 [www] Mark items complete in Clang 9 as 'Clang 9' rather than 'SVN'.
Don't turn the boxes green yet, since Clang 9 hasn't been released.

llvm-svn: 370795
2019-09-03 17:49:51 +00:00
Richard Smith ff9bf925e7 [c++20] Add support for designated direct-list-initialization syntax.
This completes the implementation of P0329R4.

llvm-svn: 370558
2019-08-31 01:00:37 +00:00
Erich Keane a8abe1f828 Fix poorly formatted HTML in the cxx_status.html file caused by adding
1668.

llvm-svn: 369286
2019-08-19 18:14:22 +00:00
Erich Keane ab00f237ac Update cxx_status.html with P1668 status.
llvm-svn: 369282
2019-08-19 17:57:27 +00:00
Erich Keane ad137fa788 Fix cxx_status html for r367027
llvm-svn: 367038
2019-07-25 17:14:37 +00:00
Erich Keane 46441fdb3c Implement P1771
As passed in the Cologne meeting and treated by Core as a DR,
[[nodiscard]] was applied to constructors so that they can be diagnosed
in cases where the user forgets a variable name for a type.

The intent is to enable the library to start using this on the
constructors of scope_guard/lock_guard.

Differential Revision: https://reviews.llvm.org/D64914

llvm-svn: 367027
2019-07-25 15:10:56 +00:00
Richard Smith 6a38205039 [c++20] P1161R3: a[b,c] is deprecated.
llvm-svn: 366630
2019-07-20 09:32:27 +00:00
Aaron Ballman 7017a6d3a3 Mark P1301R4 in C++2a as being SVN instead.
llvm-svn: 366629
2019-07-20 08:57:08 +00:00
Aaron Ballman 1358af27c0 We support P1301R4 in C++2a as of r366626.
llvm-svn: 366628
2019-07-20 08:24:56 +00:00
Richard Smith 1f8aa536f3 [cxx_status] Update status page for WG21 Cologne meeting motions.
Note that many of the paper links will be dead until the post-meeting
mailing is released.

llvm-svn: 366627
2019-07-20 08:20:54 +00:00
Richard Smith 7939ba08ab [cxx2a] P1236R1: the validity of a left shift does not depend on the
value of the LHS operand.

llvm-svn: 364265
2019-06-25 01:45:26 +00:00