Commit Graph

5 Commits

Author SHA1 Message Date
Richard Smith b5f2c4e45b PR23029 / C++ DR2233: Allow expanded parameter packs to follow
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.
2020-06-02 13:48:59 -07:00
Richard Smith 9e77f524b5 Fix handling of class member access into a vector type.
When handling a member access into a non-class, non-ObjC-object type, we
would perform a lookup into the surrounding scope as if for an
unqualified lookup. If the member access was followed by a '<' and this
lookup (or the typo-correction for it) found a template name, we'd treat
the member access as naming that template.

Now we treat such accesses as never naming a template if the type of the
object expression is of vector type, so that vector component accesses
are never misinterpreted as naming something else. This is not entirely
correct, since it is in fact valid to name a template from the enclosing
scope in this context, when invoking a pseudo-destructor for the vector
type via an alias template, but that's very much a corner case, and this
change leaves that case only as broken as the corresponding case for
Objective-C types is.

This incidentally adds support for dr2292, which permits a 'template'
keyword at the start of a member access naming a pseudo-destructor.

llvm-svn: 368940
2019-08-14 22:57:50 +00:00
Nicolas Lesser 3cde5e4a4c [C++17] Reject shadowing of capture by parameter in lambda
Summary:
This change rejects the shadowing of a capture by a parameter in lambdas in C++17.

```
int main() {
  int a;
  auto f = [a](int a) { return a; };
}
```

results in:

```
main.cpp:3:20: error: a lambda parameter cannot shadow an explicitly captured entity
  auto f = [a](int a) { return a; };
                   ^
main.cpp:3:13: note: variable a is explicitly captured here
  auto f = [a](int a) { return a; };
            ^
```

Reviewers: rsmith

Reviewed By: rsmith

Subscribers: lebedev.ri, erik.pilkington, cfe-commits

Differential Revision: https://reviews.llvm.org/D53595

llvm-svn: 345308
2018-10-25 20:15:03 +00:00
Richard Smith b6070db0d0 DR1672, DR1813, DR1881, DR2120: Implement recent fixes to "standard
layout" rules.

The new rules say that a standard-layout struct has its first non-static
data member and all base classes at offset 0, and consider a class to
not be standard-layout if that would result in multiple subobjects of a
single type having the same address.

We track "is C++11 standard-layout class" separately from "is
standard-layout class" so that the ABIs that need this information can
still use it.

Differential Revision: https://reviews.llvm.org/D45176

llvm-svn: 329332
2018-04-05 18:55:37 +00:00
Aaron Ballman 33e90d160b Implement DR2229, which prohibits unnamed bit-fields from having qualifiers in C++.
llvm-svn: 327781
2018-03-17 21:08:40 +00:00