DR2303 fixes the case where the derived-base match for template
deduction is ambiguous if a base-of-base ALSO matches. The canonical
example (as shown in the test) is just like the MSVC implementation of
std::tuple.
This fixes a fairly sizable issue, where if a user inherits from
std::tuple on Windows (with the MS STL), they cannot use that type to
call a function that takes std::tuple.
Differential Revision: https://reviews.llvm.org/D84048
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.
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.
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.)
Improve consistency when printing test results:
Previously we were using different labels for group names (the header
for the list of, e.g., failing tests) and summary count lines. For
example, "Failing Tests"/"Unexpected Failures". This commit changes lit
to label things consistently.
Improve wording of labels:
When talking about individual test results, the first word in
"Unexpected Failures", "Expected Passes", and "Individual Timeouts" is
superfluous. Some labels contain the word "Tests" and some don't.
Let's simplify the names.
Before:
```
Failing Tests (1):
...
Expected Passes : 3
Unexpected Failures: 1
```
After:
```
Failed Tests (1):
...
Passed: 3
Failed: 1
```
Reviewed By: ldionne
Differential Revision: https://reviews.llvm.org/D77708
parameters with default arguments.
Directly follow the wording by relaxing the AST invariant that all
parameters after one with a default arguemnt also have default
arguments, and removing the diagnostic on missing default arguments
on a pack-expanded parameter following a parameter with a default
argument.
Testing also revealed that we need to special-case explicit
specializations of templates with a pack following a parameter with a
default argument, as such explicit specializations are otherwise
impossible to write. The standard wording doesn't address this case; a
issue has been filed.
This exposed a bug where we would briefly consider a parameter to have
no default argument while we parse a delay-parsed default argument for
that parameter, which is also fixed.
Partially incorporates a patch by Raul Tambre.
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.
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
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
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
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.
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).
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
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.
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.
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.
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.
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.
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.
Method '-[NSCoder decodeValueOfObjCType:at:]' is not only deprecated
but also a security hazard, hence a loud check.
Differential Revision: https://reviews.llvm.org/D71728
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...] {};
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).
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
Erich Keane