Author: ericwf
Date: Fri Mar 3 16:35:58 2017
New Revision: 296919
URL: http://llvm.org/viewvc/llvm-project?rev=296919&view=rev
Log:
Fix hash requirements check in __hash_table.
r296565 attempted to add better diagnostics when an unordered container
is instantiated with a hash that doesn't meet the Hash requirements.
However I mistakenly checked the wrong set of requirements. Specifically
it checked if the hash met the requirements for specializations of
std::hash. However these requirements are stricter than the generic
Hash requirements.
This patch fixes the assertions to only check the Hash requirements.
Modified:
libcxx/trunk/include/__hash_table
libcxx/trunk/include/utility
libcxx/trunk/test/libcxx/containers/unord/unord.set/missing_hash_specialization.fail.cpp
Modified: libcxx/trunk/include/__hash_table
URL:
http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/__hash_table?rev=296919&r1=296918&r2=296919&view=diff
==============================================================================
--- libcxx/trunk/include/__hash_table (original)
+++ libcxx/trunk/include/__hash_table Fri Mar 3 16:35:58 2017
@@ -871,16 +871,15 @@ public:
template <class _Key, class _Hash, class _Equal, class _Alloc>
struct __diagnose_hash_table_helper {
static constexpr bool __trigger_diagnostics()
- _LIBCPP_DIAGNOSE_WARNING(__has_enabled_hash<_Key, _Hash>::value
+ _LIBCPP_DIAGNOSE_WARNING(__check_hash_requirements<_Key, _Hash>::value
&& !__invokable<_Hash const&, _Key const&>::value,
"the specified hash functor does not provide a const call operator")
_LIBCPP_DIAGNOSE_WARNING(is_copy_constructible<_Equal>::value
&& !__invokable<_Equal const&, _Key const&, _Key
const&>::value,
"the specified comparator type does not provide a const call operator")
{
- static_assert(__has_enabled_hash<_Key, _Hash>::value,
- "the specified hash functor does not meet the requirements for an "
- "enabled hash");
+ static_assert(__check_hash_requirements<_Key, _Hash>::value,
+ "the specified hash does not meet the Hash requirements");
static_assert(is_copy_constructible<_Equal>::value,
"the specified comparator is required to be copy constructible");
return true;
Modified: libcxx/trunk/include/utility
URL:
http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/utility?rev=296919&r1=296918&r2=296919&view=diff
==============================================================================
--- libcxx/trunk/include/utility (original)
+++ libcxx/trunk/include/utility Fri Mar 3 16:35:58 2017
@@ -1560,14 +1560,19 @@ struct _LIBCPP_TEMPLATE_VIS hash<nullptr
#endif
#ifndef _LIBCPP_CXX03_LANG
-template <class _Key, class _Hash = std::hash<_Key> >
-using __has_enabled_hash = integral_constant<bool,
- is_default_constructible<_Hash>::value &&
+template <class _Key, class _Hash>
+using __check_hash_requirements = integral_constant<bool,
is_copy_constructible<_Hash>::value &&
is_move_constructible<_Hash>::value &&
__invokable_r<size_t, _Hash, _Key const&>::value
>;
+template <class _Key, class _Hash = std::hash<_Key> >
+using __has_enabled_hash = integral_constant<bool,
+ __check_hash_requirements<_Key, _Hash>::value &&
+ is_default_constructible<_Hash>::value
+>;
+
#if _LIBCPP_STD_VER > 14
template <class _Type, class>
using __enable_hash_helper_imp = _Type;
Modified:
libcxx/trunk/test/libcxx/containers/unord/unord.set/missing_hash_specialization.fail.cpp
URL:
http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/libcxx/containers/unord/unord.set/missing_hash_specialization.fail.cpp?rev=296919&r1=296918&r2=296919&view=diff
==============================================================================
---
libcxx/trunk/test/libcxx/containers/unord/unord.set/missing_hash_specialization.fail.cpp
(original)
+++
libcxx/trunk/test/libcxx/containers/unord/unord.set/missing_hash_specialization.fail.cpp
Fri Mar 3 16:35:58 2017
@@ -23,14 +23,48 @@
#include <utility>
using VT = std::pair<int, int>;
-using Set = std::unordered_set<VT>;
+
+struct BadHashNoCopy {
+ BadHashNoCopy() = default;
+ BadHashNoCopy(BadHashNoCopy const&) = delete;
+
+ template <class T>
+ size_t operator()(T const&) const { return 0; }
+};
+
+struct BadHashNoCall {
+
+};
+
+
+struct GoodHashNoDefault {
+ explicit GoodHashNoDefault(void*) {}
+ template <class T>
+ size_t operator()(T const&) const { return 0; }
+};
int main() {
- Set s; // expected-error@__hash_table:* {{the specified hash functor does
not meet the requirements for an enabled hash}}
+ {
+ using Set = std::unordered_set<VT>;
+ Set s; // expected-error@__hash_table:* {{the specified hash does not meet
the Hash requirements}}
+
// FIXME: It would be great to suppress the below diagnostic all together.
// but for now it's sufficient that it appears last. However there is
// currently no way to test the order diagnostics are issued.
// expected-error@memory:* {{call to implicitly-deleted default constructor
of 'std::__1::hash<std::__1::pair<int, int> >'}}
+ }
+ {
+ using Set = std::unordered_set<int, BadHashNoCopy>;
+ Set s; // expected-error@__hash_table:* {{the specified hash does not meet
the Hash requirements}}
+ }
+ {
+ using Set = std::unordered_set<int, BadHashNoCall>;
+ Set s; // expected-error@__hash_table:* {{the specified hash does not meet
the Hash requirements}}
+ }
+ {
+ using Set = std::unordered_set<int, GoodHashNoDefault>;
+ Set s(/*bucketcount*/42, GoodHashNoDefault(nullptr));
+ }
}
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