libcxx initial import

llvm-svn: 103490
diff --git a/libcxx/src/stdexcept.cpp b/libcxx/src/stdexcept.cpp
new file mode 100644
index 0000000..e936188
--- /dev/null
+++ b/libcxx/src/stdexcept.cpp
@@ -0,0 +1,179 @@
+//===------------------------ stdexcept.cpp -------------------------------===//
+//
+// ÊÊÊÊÊÊÊÊÊÊÊÊÊÊÊÊÊÊÊÊThe LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "stdexcept"
+#include "new"
+#include "string"
+#include <cstdlib>
+#include <cstring>
+#include <cstdint>
+#include <cstddef>
+#include "system_error"
+#include <libkern/OSAtomic.h>
+
+// Note:  optimize for size
+
+#pragma GCC visibility push(hidden)
+
+namespace
+{
+
+class __libcpp_nmstr
+{
+private:
+    const char* str_;
+
+    typedef std::size_t unused_t;
+    typedef std::int32_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 throw() {return (count_t&)(*(str_ - sizeof(count_t)));}
+public:
+    explicit __libcpp_nmstr(const char* msg);
+    __libcpp_nmstr(const __libcpp_nmstr& s) _LIBCPP_CANTTHROW;
+    __libcpp_nmstr& operator=(const __libcpp_nmstr& s) _LIBCPP_CANTTHROW;
+    ~__libcpp_nmstr() _LIBCPP_CANTTHROW;
+    const char* c_str() const throw() {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::strcpy(const_cast<char*>(c_str()), msg);
+}
+
+inline
+__libcpp_nmstr::__libcpp_nmstr(const __libcpp_nmstr& s)
+    : str_(s.str_)
+{
+    OSAtomicIncrement32Barrier(&count());
+}
+
+__libcpp_nmstr&
+__libcpp_nmstr::operator=(const __libcpp_nmstr& s)
+{
+    const char* p = str_;
+    str_ = s.str_;
+    OSAtomicIncrement32Barrier(&count());
+    if (OSAtomicDecrement32((count_t*)(p-sizeof(count_t))) < 0)
+        delete [] (p-offset);
+    return *this;
+}
+
+inline
+__libcpp_nmstr::~__libcpp_nmstr()
+{
+    if (OSAtomicDecrement32(&count()) < 0)
+        delete [] (str_ - offset);
+}
+
+}
+
+#pragma GCC visiblity pop
+
+namespace std  // purposefully not using versioning namespace
+{
+
+logic_error::logic_error(const string& msg)
+{
+    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
+    ::new(&s) __libcpp_nmstr(msg.c_str());
+}
+
+logic_error::logic_error(const char* msg)
+{
+    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
+    ::new(&s) __libcpp_nmstr(msg);
+}
+
+logic_error::logic_error(const logic_error& le) throw()
+{
+    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
+    ::new(&s) __libcpp_nmstr((const __libcpp_nmstr&)le.__imp_);
+}
+
+logic_error&
+logic_error::operator=(const logic_error& le) throw()
+{
+    __libcpp_nmstr& s1 = (__libcpp_nmstr&)__imp_;
+    const __libcpp_nmstr& s2 = (const __libcpp_nmstr&)le.__imp_;
+    s1 = s2;
+    return *this;
+}
+
+logic_error::~logic_error() throw()
+{
+    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
+    s.~__libcpp_nmstr();
+}
+
+const char*
+logic_error::what() const throw()
+{
+    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
+    return s.c_str();
+}
+
+runtime_error::runtime_error(const string& msg)
+{
+    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
+    ::new(&s) __libcpp_nmstr(msg.c_str());
+}
+
+runtime_error::runtime_error(const char* msg)
+{
+    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
+    ::new(&s) __libcpp_nmstr(msg);
+}
+
+runtime_error::runtime_error(const runtime_error& le) throw()
+{
+    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
+    ::new(&s) __libcpp_nmstr((const __libcpp_nmstr&)le.__imp_);
+}
+
+runtime_error&
+runtime_error::operator=(const runtime_error& le) throw()
+{
+    __libcpp_nmstr& s1 = (__libcpp_nmstr&)__imp_;
+    const __libcpp_nmstr& s2 = (const __libcpp_nmstr&)le.__imp_;
+    s1 = s2;
+    return *this;
+}
+
+runtime_error::~runtime_error() throw()
+{
+    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
+    s.~__libcpp_nmstr();
+}
+
+const char*
+runtime_error::what() const throw()
+{
+    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
+    return s.c_str();
+}
+
+domain_error::~domain_error() throw() {}
+invalid_argument::~invalid_argument() throw() {}
+length_error::~length_error() throw() {}
+out_of_range::~out_of_range() throw() {}
+
+range_error::~range_error() throw() {}
+overflow_error::~overflow_error() throw() {}
+underflow_error::~underflow_error() throw() {}
+
+}  // std