Import libc++ trunk r224926. This fixes a number of bugs, completes

C++14 support[1], adds more C++1z features[2], and fixes the following
LWG issues[3]:

1450: Contradiction in regex_constants
2003: String exception inconsistency in erase.
2075: Progress guarantees, lock-free property, and scheduling
      assumptions
2104: unique_lock move-assignment should not be noexcept
2112: User-defined classes that cannot be derived from
2132: std::function ambiguity
2135: Unclear requirement for exceptions thrown in
      condition_variable::wait()
2142: packaged_task::operator() synchronization too broad?
2182: Container::[const_]reference types are misleadingly specified
2186: Incomplete action on async/launch::deferred
2188: Reverse iterator does not fully support targets that overload
      operator&
2193: Default constructors for standard library containers are explicit
2205: Problematic postconditions of regex_match and regex_search
2213: Return value of std::regex_replace
2240: Probable misuse of term "function scope" in [thread.condition]
2252: Strong guarantee on vector::push_back() still broken with C++11?
2257: Simplify container requirements with the new algorithms
2258: a.erase(q1, q2) unable to directly return q2
2263: Comparing iterators and allocator pointers with different
      const-character
2268: Setting a default argument in the declaration of a member
      function assign of std::basic_string
2271: regex_traits::lookup_classname specification unclear
2272: quoted should use char_traits::eq for character comparison
2278: User-defined literals for Standard Library types
2280: begin / end for arrays should be constexpr and noexcept
2285: make_reverse_iterator
2288: Inconsistent requirements for shared mutexes
2291: std::hash is vulnerable to collision DoS attack
2293: Wrong facet used by num_put::do_put
2299: Effects of inaccessible key_compare::is_transparent type are not
      clear
2301: Why is std::tie not constexpr?
2304: Complexity of count in unordered associative containers
2306: match_results::reference should be value_type&, not const
      value_type&
2308: Clarify container destructor requirements w.r.t. std::array
2313: tuple_size should always derive from integral_constant<size_t, N>
2314: apply() should return decltype(auto) and use decay_t before
      tuple_size
2315: weak_ptr should be movable
2316: weak_ptr::lock() should be atomic
2317: The type property queries should be UnaryTypeTraits returning
      size_t
2320: select_on_container_copy_construction() takes allocators, not
      containers
2322: Associative(initializer_list, stuff) constructors are
      underspecified
2323: vector::resize(n, t)'s specification should be simplified
2324: Insert iterator constructors should use addressof()
2329: regex_match()/regex_search() with match_results should forbid
      temporary strings
2330: regex("meow", regex::icase) is technically forbidden but should
      be permitted
2332: regex_iterator/regex_token_iterator should forbid temporary
      regexes
2339: Wording issue in nth_element
2341: Inconsistency between basic_ostream::seekp(pos) and
      basic_ostream::seekp(off, dir)
2344: quoted()'s interaction with padding is unclear
2346: integral_constant's member functions should be marked noexcept
2350: min, max, and minmax should be constexpr
2356: Stability of erasure in unordered associative containers
2357: Remaining "Assignable" requirement
2359: How does regex_constants::nosubs affect basic_regex::mark_count()?
2360: reverse_iterator::operator*() is unimplementable

[1] http://libcxx.llvm.org/cxx1y_status.html
[2] http://libcxx.llvm.org/cxx1z_status.html
[3] http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html

Exp-run:	antoine
MFC after:	1 month

1 files changed, 14 insertions, 108 deletions

diff --git a/contrib/libc++/src/stdexcept.cpp b/contrib/libc++/src/stdexcept.cpp
index a4207d6..aff4b18 100644
--- a/contrib/libc++/src/stdexcept.cpp
+++ b/contrib/libc++/src/stdexcept.cpp
@@ -7,123 +7,42 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "__refstring"
 #include "stdexcept"
 #include "new"
 #include "string"
-#include <cstdlib>
-#include <cstring>
-#include <cstdint>
-#include <cstddef>
 #include "system_error"
 
 #ifndef __has_include
 #define __has_include(inc) 0
 #endif
 
-#ifdef __APPLE__
+/* For _LIBCPPABI_VERSION */
+#if __has_include(<cxxabi.h>) || defined(__APPLE_) || defined(LIBCXXRT)
 #include <cxxabi.h>
-#elif defined(LIBCXXRT) || __has_include(<cxxabi.h>)
-#include <cxxabi.h>
-#endif
-
-// Note:  optimize for size
-
-#if ! defined(_LIBCPP_MSVC)
-#pragma GCC visibility push(hidden)
 #endif
 
-namespace
-{
-
-class __libcpp_nmstr
-{
-private:
-    const char* str_;
-
-    typedef std::size_t unused_t;
-    typedef std::ptrdiff_t count_t;
-
-    static const std::ptrdiff_t offset = static_cast<std::ptrdiff_t>(2*sizeof(unused_t) +
-                                                                       sizeof(count_t));
-
-    count_t& count() const _NOEXCEPT {return (count_t&)(*(str_ - sizeof(count_t)));}
-public:
-    explicit __libcpp_nmstr(const char* msg);
-    __libcpp_nmstr(const __libcpp_nmstr& s) _NOEXCEPT;
-    __libcpp_nmstr& operator=(const __libcpp_nmstr& s) _NOEXCEPT;
-    ~__libcpp_nmstr();
-    const char* c_str() const _NOEXCEPT {return str_;}
-};
-
-__libcpp_nmstr::__libcpp_nmstr(const char* msg)
-{
-    std::size_t len = strlen(msg);
-    str_ = new char[len + 1 + offset];
-    unused_t* c = (unused_t*)str_;
-    c[0] = c[1] = len;
-    str_ += offset;
-    count() = 0;
-    std::memcpy(const_cast<char*>(c_str()), msg, len + 1);
-}
-
-inline
-__libcpp_nmstr::__libcpp_nmstr(const __libcpp_nmstr& s) _NOEXCEPT
-    : str_(s.str_)
-{
-    __sync_add_and_fetch(&count(), 1);
-}
-
-__libcpp_nmstr&
-__libcpp_nmstr::operator=(const __libcpp_nmstr& s) _NOEXCEPT
-{
-    const char* p = str_;
-    str_ = s.str_;
-    __sync_add_and_fetch(&count(), 1);
-    if (__sync_add_and_fetch((count_t*)(p-sizeof(count_t)), count_t(-1)) < 0)
-        delete [] (p-offset);
-    return *this;
-}
-
-inline
-__libcpp_nmstr::~__libcpp_nmstr()
-{
-    if (__sync_add_and_fetch(&count(), count_t(-1)) < 0)
-        delete [] (str_ - offset);
-}
-
-}
-
-#if ! defined(_LIBCPP_MSVC)
-#pragma GCC visibility pop
-#endif
+static_assert(sizeof(std::__libcpp_refstring) == sizeof(const char *), "");
 
 namespace std  // purposefully not using versioning namespace
 {
 
-logic_error::logic_error(const string& msg)
+logic_error::logic_error(const string& msg) : __imp_(msg.c_str())
 {
-    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
-    ::new(&s) __libcpp_nmstr(msg.c_str());
 }
 
-logic_error::logic_error(const char* msg)
+logic_error::logic_error(const char* msg) : __imp_(msg)
 {
-    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
-    ::new(&s) __libcpp_nmstr(msg);
 }
 
-logic_error::logic_error(const logic_error& le) _NOEXCEPT
+logic_error::logic_error(const logic_error& le) _NOEXCEPT : __imp_(le.__imp_)
 {
-    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
-    ::new(&s) __libcpp_nmstr((const __libcpp_nmstr&)le.__imp_);
 }
 
 logic_error&
 logic_error::operator=(const logic_error& le) _NOEXCEPT
 {
-    __libcpp_nmstr& s1 = (__libcpp_nmstr&)__imp_;
-    const __libcpp_nmstr& s2 = (const __libcpp_nmstr&)le.__imp_;
-    s1 = s2;
+    __imp_ = le.__imp_;
     return *this;
 }
 
@@ -131,43 +50,33 @@ logic_error::operator=(const logic_error& le) _NOEXCEPT
 
 logic_error::~logic_error() _NOEXCEPT
 {
-    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
-    s.~__libcpp_nmstr();
 }
 
 const char*
 logic_error::what() const _NOEXCEPT
 {
-    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
-    return s.c_str();
+    return __imp_.c_str();
 }
 
 #endif
 
-runtime_error::runtime_error(const string& msg)
+runtime_error::runtime_error(const string& msg) : __imp_(msg.c_str())
 {
-    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
-    ::new(&s) __libcpp_nmstr(msg.c_str());
 }
 
-runtime_error::runtime_error(const char* msg)
+runtime_error::runtime_error(const char* msg) : __imp_(msg)
 {
-    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
-    ::new(&s) __libcpp_nmstr(msg);
 }
 
 runtime_error::runtime_error(const runtime_error& le) _NOEXCEPT
+  : __imp_(le.__imp_)
 {
-    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
-    ::new(&s) __libcpp_nmstr((const __libcpp_nmstr&)le.__imp_);
 }
 
 runtime_error&
 runtime_error::operator=(const runtime_error& le) _NOEXCEPT
 {
-    __libcpp_nmstr& s1 = (__libcpp_nmstr&)__imp_;
-    const __libcpp_nmstr& s2 = (const __libcpp_nmstr&)le.__imp_;
-    s1 = s2;
+    __imp_ = le.__imp_;
     return *this;
 }
 
@@ -175,15 +84,12 @@ runtime_error::operator=(const runtime_error& le) _NOEXCEPT
 
 runtime_error::~runtime_error() _NOEXCEPT
 {
-    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
-    s.~__libcpp_nmstr();
 }
 
 const char*
 runtime_error::what() const _NOEXCEPT
 {
-    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
-    return s.c_str();
+    return __imp_.c_str();
 }
 
 domain_error::~domain_error() _NOEXCEPT {}