Commit Graph

1495 Commits

Author SHA1 Message Date
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
Hubert Tong a73a81dce5 [www] Update make_cxx_dr_status for v10; regenerate cxx_dr_status.html
Summary: Update `latest_release` to reflect the release of Clang 10.

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D78172
2020-04-15 10:45:00 -04:00
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
Nick Desaulniers 91cdbd521a clang: Switch C compilations to C17 by default.
Summary:
Matches GCC 8.1 (2018).

Updates documentation+release notes as well.

See also https://reviews.llvm.org/rL220244.

Reviewers: rsmith, aaron.ballman

Reviewed By: rsmith, aaron.ballman

Subscribers: aaron.ballman, dschuff, aheejin, simoncook, s.egerton, cfe-commits, hans, srhines

Tags: #clang

Differential Revision: https://reviews.llvm.org/D75383
2020-03-02 09:39:26 -08:00
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
Sylvestre Ledru 7ae1347fb2 clang analyzer: Fix the webpage rendering 2020-02-17 10:03:20 +01:00
Richard Smith b74a381296 [cxx_status] New papers from Prague 2020 WG21 meeting. 2020-02-15 02:16:21 -08:00
Richard Smith 9ce6dc9872 CWG1423: don't permit implicit conversion of nullptr_t to bool.
The C++ rules briefly allowed this, but the rule changed nearly 10 years
ago and we never updated our implementation to match. However, we've
warned on this by default for a long time, and no other compiler accepts
(even as an extension).
2020-02-11 06:52:45 -08:00
John Regehr 42ca012bef remove outdated comparison with other open-source c++ compilers 2020-02-11 00:05:16 -07:00
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
Richard Smith 96c899449b C++ DR2026: static storage duration variables are not zeroed before
constant initialization.

Removing this zeroing regressed our code generation in a few cases, also
fixed here. We now compute whether a variable has constant destruction
even if it doesn't have a constant initializer, by trying to destroy a
default-initialized value, and skip emitting a trivial default
constructor for a variable even if it has non-trivial (but perhaps
constant) destruction.
2020-02-06 16:37:22 -08:00
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 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 f041e9ad70 CWG2352: Allow qualification conversions during reference binding.
The language wording change forgot to update overload resolution to rank
implicit conversion sequences based on qualification conversions in
reference bindings. The anticipated resolution for that oversight is
implemented here -- we order candidates based on qualification
conversion, not only on top-level cv-qualifiers, including ranking
reference bindings against non-reference bindings if they differ in
non-top-level qualification conversions.

For OpenCL/C++, this allows reference binding between pointers with
differing (nested) address spaces. This makes the behavior of reference
binding consistent with that of implicit pointer conversions, as is the
purpose of this change, but that pre-existing behavior for pointer
conversions is itself probably not correct. In any case, it's now
consistently the same behavior and implemented in only one place.

This reinstates commit de21704ba9,
reverted in commit d8018233d1, with
workarounds for some overload resolution ordering problems introduced by
CWG2352.
2020-01-09 18:24:06 -08:00
Alexander Lanin e5a56f2d50 Remove outdated svn/git information from hacking page
The patch files section is redundant to https://llvm.org/docs/GettingStarted.html.
There is nothing clang specific here. We are talking about a monorepo after all.
While it may seem nice to have one single clang page which explains everything,
it's not: It doesn't cover the topics in sufficient depth, it's redundant to
other pages and it's hard to keep it up to date as we see with the svn
instructions.
2020-01-03 14:13:40 -05:00
David Blaikie d8018233d1 Revert "CWG2352: Allow qualification conversions during reference binding."
This reverts commit de21704ba9.

Regressed/causes this to error due to ambiguity:

  void f(const int * const &);
  void f(int *);
  int main() {
    int * x;
    f(x);
  }

(in case it's important - the original case where this turned up was a
member function overload in a class template with, essentially:

  f(const T1&)
  f(T2*)

(where T1 == X const *, T2 == X))

It's not super clear to me if this ^ is expected behavior, in which case
I'm sorry about the revert & happy to look into ways to fix the original
code.
2019-12-27 12:27:20 -08:00
Sylvestre Ledru 7ece0ee3dd features.html: Remove some old info 2019-12-21 10:52:39 +01:00
Sylvestre Ledru a0ce615573 clang is now under the apache2 license 2019-12-21 10:52:30 +01:00
Sylvestre Ledru 384a287a99 Remove a gcc 4.9 comparison as it doesn't make sense 2019-12-21 10:46:45 +01:00
Richard Smith de21704ba9 CWG2352: Allow qualification conversions during reference binding.
The language wording change forgot to update overload resolution to rank
implicit conversion sequences based on qualification conversions in
reference bindings. The anticipated resolution for that oversight is
implemented here -- we order candidates based on qualification
conversion, not only on top-level cv-qualifiers.

For OpenCL/C++, this allows reference binding between pointers with
differing (nested) address spaces. This makes the behavior of reference
binding consistent with that of implicit pointer conversions, as is the
purpose of this change, but that pre-existing behavior for pointer
conversions is itself probably not correct. In any case, it's now
consistently the same behavior and implemented in only one place.
2019-12-19 18:37:55 -08:00
Artem Dergachev b284005072 [analyzer] Add a syntactic security check for ObjC NSCoder API.
Method '-[NSCoder decodeValueOfObjCType:at:]' is not only deprecated
but also a security hazard, hence a loud check.

Differential Revision: https://reviews.llvm.org/D71728
2019-12-19 14:54:29 -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
Gabor Marton 4cfb91f1ef [Analyzer][Docs][NFC] Add CodeChecker to the command line tools
We add a new common html file that documents the available command line
tools. Also a new html is added for a brief description of CodeChecker,
this way complementing scan-build.

Differential Revision: https://reviews.llvm.org/D70439
2019-12-12 14:22:52 +01:00
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 3a7a22445e [www] More HTTPS and outdated link fixes.
Resolves D69981.
2019-11-08 14:41:27 -08:00
Artem Dergachev 5e0fb64842 [analyzer] Add test cases for the unsupported C++ constructor modeling.
Namely, for the following items:
- Handle constructors within new[];
- Handle constructors for default arguments.

Update the open projects page with a link to the newly added tests
and more hints for potential contributors.

Patch by Daniel Krupp!

Differential Revision: https://reviews.llvm.org/D69308
2019-11-07 17:15:53 -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
Chandler Carruth dc1499b90d Improve Clang's getting involved document and make it more inclusive in wording.
Summary: Working with Meike and others to improve the wording in this document.

Reviewers: klimek

Subscribers: mcrosier, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D69351
2019-10-23 16:11:24 -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 344df110e5 Implements CWG 1601 in [over.ics.rank/4.2]
Summary:
The overload resolution for enums with a fixed underlying type has changed in the C++14 standard. This patch implements the new rule.

Patch by Mark de Wever!

Reviewers: rsmith

Reviewed By: rsmith

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D65695

llvm-svn: 373866
2019-10-06 18:50:40 +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