Also add extension warnings for the cases that are disallowed by the
current rules for destructor name lookup, refactor and simplify the
lookup code, and improve the diagnostic quality when lookup fails.
The special case we previously supported for converting
p->N::S<int>::~S() from naming a class template into naming a
specialization thereof is subsumed by a more general rule here (which is
also consistent with Clang's historical behavior and that of other
compilers): if we can't find a suitable S in N, also look in N::S<int>.
The extension warnings are off by default, except for a warning when
lookup for p->N::S::~T() looks for T in scope instead of in N (or N::S).
That seems sufficiently heinous to warn on by default, especially since
we can't support it for a dependent nested-name-specifier.
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
types are needed to compute the return type of a defaulted operator<=>.
This raises the question of what to do if return type deduction fails.
The standard doesn't say, and implementations vary, so for now reject
that case eagerly to keep our options open.
when building a defaulted comparison.
As a convenient way of asking whether `x @ y` is valid and building it,
we previouly always performed overload resolution and built an
overloaded expression, which would both end up picking a builtin
operator candidate when given a non-overloadable type. But that's not
quite right, because it can result in our finding a user-declared
operator overload, which we should never do when applying operators
non-overloadable types.
Handle this more correctly: skip overload resolution when building
`x @ y` if the operands are not overloadable. But still perform overload
resolution (considering only builtin candidates) when checking validity,
as we don't have any other good way to ask whether a binary operator
expression would be valid.
Now with concepts support merged and mostly complete, we do not need -fconcepts-ts
(which was also misleading as we were not implementing the TS) and can enable
concepts features under C++2a. A warning will be generated if users still attempt
to use -fconcepts-ts.
This requires us to essentially fully form the body of the defaulted
comparison, but from an unevaluated context. Naively this would require
generating the function definition twice; instead, we ensure that the
function body is implicitly defined before performing the check, and
walk the actual body where possible.
function.
We need to perform unqualified lookups from the context of a defaulted
comparison, but not until we implicitly define the function, at which
point we can't do those lookups any more. So perform the lookup from the
end of the class containing the =default declaration and store the
lookup results on the defaulted function until we synthesize the body.
Array members are not yet handled. In addition, defaulted comparisons
can't yet find comparison operators by unqualified lookup (only by
member lookup and ADL). These issues will be fixed in follow-on changes.
template specialization if there is no matching non-template function.
This exposed a couple of related bugs:
- we would sometimes substitute into a friend template instead of a
suitable non-friend declaration; this would now crash because we'd
decide the specialization of the friend is a redeclaration of itself
- ADL failed to properly handle the case where an invisible local
extern declaration redeclares an invisible friend
Both are fixed herein: in particular, we now never make invisible
friends or local extern declarations visible to name lookup unless
they are the only declaration of the entity. (We already mostly did
this for local extern declarations.)
llvm-svn: 350505
Diagnose the name of the class being shadowed by using declarations, and
improve the diagnostics for the case where the name of the class is
shadowed by a non-static data member in a class with constructors. In
the latter case, we now always give the "member with the same name as
its class" diagnostic regardless of the relative order of the member and
the constructor, rather than giving an inscrutible diagnostic if the
constructor appears second.
llvm-svn: 335182
Prior to this patch clang would not error here:
template <class T> struct B;
template <class T> struct A {
void foo();
void foo2();
void test1() {
B<T>::foo(); // OK, foo is declared in A<int> - matches type of 'this'.
B<T>::foo2(); // This should be an error!
// foo2 is found in B<int>, 'base unrelated' to 'this'.
}
};
template <class T> struct B : A<T> {
using A<T>::foo2;
};
llvm-svn: 311851
into IDNS_Tag in C++, because they conflict with redeclarations of tags. (This
doesn't affect elaborated-type-specifier lookup, which looks for IDNS_Type in
C++).
llvm-svn: 256985
This is the 5th Lit test patch.
Expanded expected diagnostics to vary by C++ dialect.
Expanded RUN line to: default, C++98/03 and C++11.
llvm-svn: 255196
Unqualified templated constructors cannot be friended and our lack of a
diagnostic led to violated invariants. Instead, raise a diagnostic when
processing the friend declaration.
This fixes PR20251.
llvm-svn: 248953
There was already an explicit check for that for the first decl. Move that
to a different place so that it's called for the following decls too. Also
don't randomly set the BitfieldSize ExprResult to true (this sets a pointer to
true internally).
Found by SLi's bot.
llvm-svn: 226306
more than one such initializer in a union, make mem-initializers override
default initializers for other union members, handle anonymous unions with
anonymous struct members better. Fix a couple of semi-related bugs exposed by
the tests for same.
llvm-svn: 196892
data member definitions when the variable has an initializer
in its declaration.
For the following code:
struct S {
static const int x = 42;
};
const int S::x = 42;
This patch changes the diagnostic from:
a.cc:4:14: error: redefinition of 'x'
const int S::x = 42;
^
a.cc:2:20: note: previous definition is here
static const int x = 42;
^
to:
a.cc:4:18: error: static data member 'x' already has an initializer
const int S::x = 42;
^
a.cc:2:24: note: previous initialization is here
static const int x = 42;
^
Differential Revision: http://llvm-reviews.chandlerc.com/D2235
llvm-svn: 195306
Unlike with namespaces, searching inside of classes requires also
checking the access to correction candidates (i.e. don't suggest a
correction to a private class member for a correction occurring outside
that class and its methods or friends).
Included is a small (one line) fix for a bug, that was uncovered while
cleaning up the unit tests, where the decls from a TypoCorrection candidate
were preserved in new TypoCorrection candidates that are derived (copied)
from the old TypoCorrection--notably when creating a new candidate by
changing the NestedNameSpecifier associated with the base idenitifer.
llvm-svn: 191449
- 'register' storage class
- dynamic exception specifications
Only the former check is enabled by default for now (the latter might be quite noisy).
llvm-svn: 183881
and split it out of -Wgnu into its own warning flag.
* In C++11, this is now a hard error (GCC has no extension here in C++11 mode).
The error can be disabled with -Wno-static-float-init, and has a fixit to
add 'constexpr'.
* In C++98, this is still an ExtWarn, but is now controlled by
-Wstatic-float-init as well as -Wgnu.
llvm-svn: 173414
Remove pre-standard restriction on explicitly-defaulted copy constructors with
'incorrect' parameter types, and instead just make those special members
non-trivial as the standard requires.
This required making CXXRecordDecl correctly handle classes which have both a
trivial and a non-trivial special member of the same kind.
This also fixes PR13217 by reimplementing DiagnoseNontrivial in terms of the
new triviality computation technology.
llvm-svn: 169667
properly, rather than faking it up by pretending that a reference member makes
the default constructor non-trivial. That leads to rejects-valids when putting
such types inside unions.
llvm-svn: 169662
Richard Smith