This reverts commit r312890 because the test case fails to compile for
older versions of Clang that reject initializing a const object without
a user defined constructor.
Since this patch should go into 5.0.1, I want to keep it an atomic change,
and will re-commit it with a fixed test case.
llvm-svn: 312891
This patch fixes llvm.org/PR34298. Previously libc++ incorrectly evaluated
the __invokable trait via the converting constructor `function(Tp)` [with Tp = std::function]
whenever the copy constructor or copy assignment operator
was required. This patch further constrains that constructor to short
circut before evaluating the troublesome SFINAE when `Tp` matches
std::function.
The original patch is from Alex Lorenz.
llvm-svn: 312890
Summary:
bad_function_call is currently an empty class, so any object files using
that class will end up with their own copy of its typeinfo, typeinfo
name and vtable, leading to unnecessary duplication that has to be
resolved by the dynamic linker. Instead, give bad_function_call a key
function and put a definition for that key function in libc++ itself, to
centralize the typeinfo and vtable.
This is consistent with the behavior for other exception classes. The
key functions are defined in libc++ rather than libc++abi since the
class is defined in the libc++ versioning namespace, so ABI
compatibility with libstdc++ is not a concern.
Guard this change behind an ABI macro, since it isn't backwards
compatible (i.e., clients built against the new libc++ headers wouldn't
be able to run against an older libc++ library).
Reviewers: mclow.lists, EricWF
Subscribers: mgorny, cfe-commits
Differential Revision: https://reviews.llvm.org/D27387
llvm-svn: 298937
Summary:
Exactly what the title says.
This patch also adds a `std::hash<nullptr_t>` specialization in C++17, but it was not added by this paper and I can't find the actual paper that adds it.
See http://wg21.link/P0513R0 for more info.
If there are no comments in the next couple of days I'll commit this
Reviewers: mclow.lists, K-ballo, EricWF
Reviewed By: EricWF
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D28938
llvm-svn: 292684
The name _LIBCPP_TYPE_VIS_ONLY is no longer accurate because both
_LIBCPP_TYPE_VIS and _LIBCPP_TYPE_VIS_ONLY expand to
__attribute__((__type_visibility__)) with Clang. The only remaining difference
is that _LIBCPP_TYPE_VIS_ONLY can be applied to templates whereas
_LIBCPP_TYPE_VIS cannot (due to dllimport/dllexport not being allowed on
templates).
This patch renames _LIBCPP_TYPE_VIS_ONLY to _LIBCPP_TEMPLATE_VIS.
llvm-svn: 291035
libc++ no longer supports C++11 compilers that don't implement `= default`.
This patch removes all instances of the feature test macro
_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS as well as the potentially dead code it hides.
llvm-svn: 287321
Although inheriting constructors have already been fixed in Clang 3.9 I still
choose to fix std::function so users can derive from it with older compilers.
llvm-svn: 276090
This patch makes the bind placeholders in std::placeholders both (1) const and
(2) constexpr (See below).
This is technically a breaking change for any code using the placeholders
outside of std::bind and depending on them being non-const. However I don't
think this will break any real world code.
(1) Previously the placeholders were non-const extern globals in all
dialects. This patch changes these extern globals to be const in all dialects.
Since the cv-qualifiers don't participate in name mangling for globals this
is an ABI compatible change.
(2) Make the placeholders constexpr in C++11 and beyond. Although LWG 2488 only
applies to C++17 I don't see any reason not to backport this change.
llvm-svn: 273824
Summary:
Exactly what it sounds like.
I plan to commit this in a couple of days assuming no objections.
Reviewers: mclow.lists, EricWF
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D20799
llvm-svn: 271464
static_cast of a pointer to object before the start of the object's
lifetime has undefined behavior.
This code triggers CFI warnings.
This change replaces C-style casts with reinterpret_cast, which is
fine per the standard, add applies an attribute to silence CFI (which
barks on reinterpret_cast, too).
llvm-svn: 260441
Summary:
This patch rewrites the C++03 `__invoke` and related meta-programming. There are a number of major changes.
`__invoke` in C++03 now has a fallback overload for when the invoke expression is ill-formed (similar to C++11). This means that the `__invoke_return` traits will return `__nat` when `__invoke(...)` is ill formed. This would previously cause a compile error.
Bullets 1-4 of `__invoke` have been rewritten. In the old version `__invoke` had 32 overloads for bullets 1 and 2,
one for each possible cv-qualified function signature with arities 0-3. 64 overloads would be needed to support member functions
with varargs. Currently these overloads were fundamentally broken. An example overload looked like:
```
template <class Rp, class Tp, class T1, class A0>
Rp __invoke(Rp (Tp::*pm)(A0) const, T1&, A0&)
```
Because `A0` appeared in two different deducible contexts it would have to deduce to be an exact match or the overload
would be rejected. This is made even worse because `A0` appears without a reference qualifier in the member function signature
and with a reference qualifier as an `__invoke` parameter. This means that only member functions that took all
of their arguments by value could be matched.
One possible fix would be to make the second occurrence of `A0` appear in a non-deducible context. This way
any type convertible to `A0` could be passed as the first parameter. The benefit of this approach is that the
signature of the member function enforces the arity and types taken by the `__invoke` signature it generates. However
nothing in the `INVOKE` specification requires this behavior.
My solution is to use a `__invoke_enable_if<PM_Type, Tp>` metafunction to selectively enable the `__invoke` overloads for bullets 1, 2, 3 and 4. It uses `__member_function_traits` to inspect and extract the return type and class type of the pointer to member. Using `__member_function_traits` to inspect `PM_Type` also allows us to reduce the number of `__invoke` overloads from 32 to 8 and add
varargs support at the same time.
Because `__invoke_enable_if` knows the exact return type of `__invoke` for bullets 1-4 we no longer need to use `decltype(__invoke(...))` to
compute the return type in the `__invoke_return*` traits. This will reduce the problems caused by `#define decltype(X) __typeof__(X)` in C++03.
Tests for this change have already been committed. All tests in `test/std/utilities/function.objects` now pass in C++03, previously there were 20 failures.
Reviewers: K-ballo, howard.hinnant, mclow.lists
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D11553
llvm-svn: 246068
Summary:
This patch fixes __not_null's detection of nullptr by breaking it down into 4 cases.
1. `__not_null(Tp const&)`: Default case. Tp is not null.
2. `__not_null(Tp* __ptr);` Case for pointers to functions.
3. `__not_null(_Ret _Class::* __ptr);` Case for pointers to members.
4. `__not_null(function<Tp> const&);`: Cases for other std::functions.
Reviewers: mclow.lists
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D11111
llvm-svn: 245335
The key changes in this patch are:
1. Remove the zero-argument overload in mem_fn. A member function must always
be invoked with at least one argument, the class instance. The zero-argument
operator()() in mem_fn would cause mem_fn to fail to compile when because
the call to '__invoke(pm)' is not well formed.
2. Prevent evaluation of '__apply_cv<Tp, Ret>' when 'Ret' is a function type.
'Ret' is a function type whenever 'Ret Tp::*' is a pointer to member function.
Attempting to add cv and ref qualifiers to a function type can cause a hard
compile error.
3. Remove the dummy overload __invoke(Rp Tp::*). It was present to help work
around #1. It will be replaced with a different '__invoke' overload that
represents a bad call to invoke.
After applying this patch the test func.wrap.func.inv/invoke.pass.cpp now
passes.
llvm-svn: 243370
The implementation of mem_fn doesn't actually require any C++11 support.
For some reason there were 17 overloads for mem_fn in C++03 when only one
is needed. This patch removes the extra overloads and uses the same implementation
of mem_fn in C++03 and C++11.
__mem_fn does require variadics to implement the call operator. Instead of
having two entirely different implementations of the __mem_fn struct, this patch
uses the same __mem_fn struct but provides different call operators when
variadics are not available.
The only thing left in <__functional_03> is the C++03 implementation of
std::function.
llvm-svn: 242959
<__functional_03> provides the C++03 definitions for std::memfun and
std::function. However the interaction between <functional> and <__functional_03>
is ugly and duplicates code needlessly. This patch cleans up how the two
headers work together.
The major changes are:
- Provide placeholders, is_bind_expression and is_placeholder in <functional>
for both C++03 and C++11.
- Provide bad_function_call, function fwd decl,
__maybe_derive_from_unary_function and __maybe_derive_from_binary_function
in <functional> for both C++03 and C++11.
- Move the <__functional_03> include to the bottom of <functional>. This makes
it easier to see how <__functional_03> interacts with <functional>
- Remove a commented out implementation of bind in C++03. It's never going
to get implemented.
- Mark almost all std::bind tests as unsupported in C++03. std::is_placeholder
works in C++03 and C++11. std::is_bind_expression is provided in C++03 but
always returns false.
llvm-svn: 242870
Although CMake adds warning flags, they are ignored in the libc++ headers
because the headers '#pragma system header' themselves.
This patch disables the system header pragma when building libc++ and fixes
the warnings that arose.
The warnings fixed were:
1. <memory> - anonymous structs are a GNU extension
2. <functional> - anonymous structs are a GNU extension.
3. <__hash_table> - Embedded preprocessor directives have undefined behavior.
4. <string> - Definition is missing noexcept from declaration.
5. <__std_stream> - Unused variable.
llvm-svn: 242623
Summary:
This patch changes std::function to use allocator_traits to rebind the allocator instead of allocator itself.
It also changes most of the tests to use `bare_allocator` where possible instead of `test_allocator`.
Reviewers: mclow.lists
Reviewed By: mclow.lists
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D8391
llvm-svn: 232686
Summary:
The bug can be found here: http://llvm.org/bugs/show_bug.cgi?id=22468
`__invoke_void_return_wrapper` is needed to properly handle calling a function that returns a value but where the std::function return type is void. Without this '-Wsystem-headers' will cause `function::operator()(...)` to not compile.
Reviewers: eugenis, K-ballo, mclow.lists
Reviewed By: mclow.lists
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D7444
llvm-svn: 228705
The SFINAE on the function __mu(Fn, Args...) that evaluates nested bind
expressions always tries to deduce the return type for Fn(Args...) even when Fn
is not a nested bind expression. This can cause hard compile errors when the
instantation of Fn(Args...) is ill-formed. This patch prevents the instantation
of __invoke_of<Fn, Args...> unless Fn is actually a bind expression.
Bug reportand patch from Michel Morin.
http://llvm.org/bugs/show_bug.cgi?id=22003
llvm-svn: 224753
workaround relied on rvalue references binding to non-function
lvalues, while the original formulation (with std::forward) does the
right thing.
llvm-svn: 124241
