references. What's more, they use this language extension in their
ATL header files (which come as part of MFC and the Win32 SDK). This patch implements support for the Microsoft extension, and addresses PR13737.
llvm-svn: 182936
While the C++ standard requires that this lookup take place only at the
definition point of a virtual destructor (C++11 [class.dtor]p12), the
Microsoft ABI may require the compiler to emit a deleting destructor
for any virtual destructor declared in the TU, including ones without
a body, requiring an operator delete() lookup for every virtual
destructor declaration. The result of the lookup should be the same
no matter which declaration is used (except in weird corner cases).
This change will cause us to reject some valid TUs in Microsoft ABI
mode, e.g.:
struct A {
void operator delete(void *);
};
struct B {
void operator delete(void *);
};
struct C : A, B {
virtual ~C();
};
As Richard points out, every virtual function declared in a TU
(including this virtual destructor) is odr-used, so it must be defined
in any program which declares it, or the program is ill formed, no
diagnostic required. Because we know that any definition of this
destructor will cause the lookup to fail, the compiler can choose to
issue a diagnostic here.
Differential Revision: http://llvm-reviews.chandlerc.com/D822
llvm-svn: 182270
selectany only applies to externally visible global variables. It has
the effect of making the data weak_odr.
The MSDN docs suggest that unused definitions can only be dropped at
linktime, so Clang uses weak instead of linkonce. MSVC optimizes away
references to constant selectany data, so it must assume that there is
only one definition, hence weak_odr.
Reviewers: espindola
Differential Revision: http://llvm-reviews.chandlerc.com/D814
llvm-svn: 182266
This patch renames getLinkage to getLinkageInternal. Only code that
needs to handle UniqueExternalLinkage specially should call this.
Linkage, as defined in the c++ standard, is provided by
getFormalLinkage. It maps UniqueExternalLinkage to ExternalLinkage.
Most places in the compiler actually want isExternallyVisible, which
handles UniqueExternalLinkage as internal.
llvm-svn: 181677
I was not able to find a case (other than the fix in r181163) where this
makes a difference, but it is a more obviously correct API to have.
llvm-svn: 181165
This change partly addresses a heinous problem we have with the
parsing of attribute arguments that are a lone identifier. Previously,
we would end up parsing the 'align' attribute of this as an expression
"(Align)":
template<unsigned Size, unsigned Align>
class my_aligned_storage
{
__attribute__((align((Align)))) char storage[Size];
};
while this would parse as a "parameter name" 'Align':
template<unsigned Size, unsigned Align>
class my_aligned_storage
{
__attribute__((align(Align))) char storage[Size];
};
The code that handles the alignment attribute would completely ignore
the parameter name, so the while the first of these would do what's
expected, the second would silently be equivalent to
template<unsigned Size, unsigned Align>
class my_aligned_storage
{
__attribute__((align)) char storage[Size];
};
i.e., use the maximal alignment rather than the specified alignment.
Address this by sniffing the "Args" provided in the TableGen
description of attributes. If the first argument is "obviously"
something that should be treated as an expression (rather than an
identifier to be matched later), parse it as an expression.
Fixes <rdar://problem/13700933>.
llvm-svn: 180973
This change partly addresses a heinous problem we have with the
parsing of attribute arguments that are a lone identifier. Previously,
we would end up parsing the 'align' attribute of this as an expression
"(Align)":
template<unsigned Size, unsigned Align>
class my_aligned_storage
{
__attribute__((align((Align)))) char storage[Size];
};
while this would parse as a "parameter name" 'Align':
template<unsigned Size, unsigned Align>
class my_aligned_storage
{
__attribute__((align(Align))) char storage[Size];
};
The code that handles the alignment attribute would completely ignore
the parameter name, so the while the first of these would do what's
expected, the second would silently be equivalent to
template<unsigned Size, unsigned Align>
class my_aligned_storage
{
__attribute__((align)) char storage[Size];
};
i.e., use the maximal alignment rather than the specified alignment.
Address this by sniffing the "Args" provided in the TableGen
description of attributes. If the first argument is "obviously"
something that should be treated as an expression (rather than an
identifier to be matched later), parse it as an expression.
Fixes <rdar://problem/13700933>.
llvm-svn: 180970
are now two distinct canonical 'AutoType's: one is the undeduced 'auto'
placeholder type, and the other is a deduced-but-dependent type. All
deduced-to-a-non-dependent-type cases are still non-canonical.
llvm-svn: 180789
Instead, we check for one line extern "C" context in linkage computation and
when deciding if a variable is a definition.
This hopefully completes the transition to having "as written" semantics for
hasExternalStorage.
llvm-svn: 180258
statement in constexpr functions. Everything which doesn't require variable
mutation is also allowed as an extension in C++11. 'void' becomes a literal
type to support constexpr functions which return 'void'.
llvm-svn: 180022
C++1y, so stop adding the 'const' there. Provide a compatibility warning for
code relying on this in C++11, with a fix-it hint. Update our lazily-written
tests to add the const, except for those ones which were testing our
implementation of this rule.
llvm-svn: 179969
It was being used correctly, but it is a very dangerous API to have around.
Instead, move the logic from the filtering to when we are deciding if we should
link two decls.
llvm-svn: 179523
Invalid redeclarations of valid explicit declarations shouldn't
take the same path as redeclarations of implicit declarations,
and invalid local extern declarations shouldn't foul things up
for everybody else.
llvm-svn: 179482
New rule:
- Method decls in @implementation are considered "redeclarations"
and inherit deprecated/availability from the @interface.
- All other cases are consider overrides, which do not inherit
deprecated/availability. For example:
(a) @interface redeclares a method in an adopted protocol.
(b) A subclass redeclares a method in a superclass.
(c) A protocol redeclares a method from another protocol it adopts.
The idea is that API authors should have the ability to easily
move availability/deprecated up and down a class/protocol hierarchy.
A redeclaration means that the availability/deprecation is a blank
slate.
Fixes <rdar://problem/13574571>
llvm-svn: 178937
This removes a bit of patching that survived r178663. Without it we can produce
better a better error message for
const int a = 5;
static const int a;
llvm-svn: 178795
Having these not be the same makes an easy to misuse API. We should audit the
uses and probably rename to something like
foo->hasExternalLinkage():
The c++ standard one. That is UniqueExternalLinkage or ExternalLinkage.
foo->hasUniqueExternalLinkage():
Is UniqueExternalLinkage.
foo->hasCogeGenExternalLinkage():
Is ExternalLinkage.
llvm-svn: 178768
This mostly reverts 178733, but keeps the tests.
I don't claim to understand how hidden sub modules work or when we need to see
them (is that documented?), but this has the same semantics and avoids adding
hasExternalLinkageUncached which has the same foot gun potential as the old
hasExternalLinkage.
Last but not least, not computing linkage when it is not needed is more
efficient.
llvm-svn: 178739
This test was exactly the opposite of what it should be. We should check if
there old decl has linkage (where it makes sense) and if the new decl has
the extern keyword.
llvm-svn: 178735
caching the linkage for a declaration before we set up its redeclaration chain,
when determining whether a declaration could be a redeclaration of something
from an unimported submodule. We actually want to look at the declaration as if
it were not a redeclaration here, so compute the linkage but don't cache it.
llvm-svn: 178733
