Merge pull request #4827 from ziglang/zig-cpp

support compiling and linking c++ code

2 files changed, 341 insertions, 0 deletions

diff --git a/lib/libcxxabi/src/include/atomic_support.h b/lib/libcxxabi/src/include/atomic_support.h
new file mode 100644
index 0000000000..4ff45eb93a
--- /dev/null
+++ b/lib/libcxxabi/src/include/atomic_support.h
@@ -0,0 +1,210 @@
+//===----------------------------------------------------------------------===////
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===////
+
+// FIXME: This file is copied from libcxx/src/include/atomic_support.h. Instead
+// of duplicating the file in libc++abi we should require that the libc++
+// sources are available when building libc++abi.
+
+#ifndef ATOMIC_SUPPORT_H
+#define ATOMIC_SUPPORT_H
+
+#include "__config"
+#include "memory" // for __libcpp_relaxed_load
+
+#if defined(__clang__) && __has_builtin(__atomic_load_n)             \
+                       && __has_builtin(__atomic_store_n)            \
+                       && __has_builtin(__atomic_add_fetch)          \
+                       && __has_builtin(__atomic_exchange_n)         \
+                       && __has_builtin(__atomic_compare_exchange_n) \
+                       && defined(__ATOMIC_RELAXED)                  \
+                       && defined(__ATOMIC_CONSUME)                  \
+                       && defined(__ATOMIC_ACQUIRE)                  \
+                       && defined(__ATOMIC_RELEASE)                  \
+                       && defined(__ATOMIC_ACQ_REL)                  \
+                       && defined(__ATOMIC_SEQ_CST)
+#   define _LIBCXXABI_HAS_ATOMIC_BUILTINS
+#elif !defined(__clang__) && defined(_GNUC_VER) && _GNUC_VER >= 407
+#   define _LIBCXXABI_HAS_ATOMIC_BUILTINS
+#endif
+
+#if !defined(_LIBCXXABI_HAS_ATOMIC_BUILTINS) && !defined(_LIBCXXABI_HAS_NO_THREADS)
+# if defined(_LIBCPP_WARNING)
+    _LIBCPP_WARNING("Building libc++ without __atomic builtins is unsupported")
+# else
+#   warning Building libc++ without __atomic builtins is unsupported
+# endif
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace {
+
+#if defined(_LIBCXXABI_HAS_ATOMIC_BUILTINS) && !defined(_LIBCXXABI_HAS_NO_THREADS)
+
+enum __libcpp_atomic_order {
+    _AO_Relaxed = __ATOMIC_RELAXED,
+    _AO_Consume = __ATOMIC_CONSUME,
+    _AO_Acquire = __ATOMIC_ACQUIRE,
+    _AO_Release = __ATOMIC_RELEASE,
+    _AO_Acq_Rel = __ATOMIC_ACQ_REL,
+    _AO_Seq     = __ATOMIC_SEQ_CST
+};
+
+template <class _ValueType, class _FromType>
+inline _LIBCPP_INLINE_VISIBILITY
+void __libcpp_atomic_store(_ValueType* __dest, _FromType __val,
+                           int __order = _AO_Seq)
+{
+    __atomic_store_n(__dest, __val, __order);
+}
+
+template <class _ValueType, class _FromType>
+inline _LIBCPP_INLINE_VISIBILITY
+void __libcpp_relaxed_store(_ValueType* __dest, _FromType __val)
+{
+    __atomic_store_n(__dest, __val, _AO_Relaxed);
+}
+
+template <class _ValueType>
+inline _LIBCPP_INLINE_VISIBILITY
+_ValueType __libcpp_atomic_load(_ValueType const* __val,
+                                int __order = _AO_Seq)
+{
+    return __atomic_load_n(__val, __order);
+}
+
+template <class _ValueType, class _AddType>
+inline _LIBCPP_INLINE_VISIBILITY
+_ValueType __libcpp_atomic_add(_ValueType* __val, _AddType __a,
+                               int __order = _AO_Seq)
+{
+    return __atomic_add_fetch(__val, __a, __order);
+}
+
+template <class _ValueType>
+inline _LIBCPP_INLINE_VISIBILITY
+_ValueType __libcpp_atomic_exchange(_ValueType* __target,
+                                    _ValueType __value, int __order = _AO_Seq)
+{
+    return __atomic_exchange_n(__target, __value, __order);
+}
+
+template <class _ValueType>
+inline _LIBCPP_INLINE_VISIBILITY
+bool __libcpp_atomic_compare_exchange(_ValueType* __val,
+    _ValueType* __expected, _ValueType __after,
+    int __success_order = _AO_Seq,
+    int __fail_order = _AO_Seq)
+{
+    return __atomic_compare_exchange_n(__val, __expected, __after, true,
+                                       __success_order, __fail_order);
+}
+
+#else // _LIBCPP_HAS_NO_THREADS
+
+enum __libcpp_atomic_order {
+    _AO_Relaxed,
+    _AO_Consume,
+    _AO_Acquire,
+    _AO_Release,
+    _AO_Acq_Rel,
+    _AO_Seq
+};
+
+template <class _ValueType, class _FromType>
+inline _LIBCPP_INLINE_VISIBILITY
+void __libcpp_atomic_store(_ValueType* __dest, _FromType __val,
+                           int = 0)
+{
+    *__dest = __val;
+}
+
+template <class _ValueType, class _FromType>
+inline _LIBCPP_INLINE_VISIBILITY
+void __libcpp_relaxed_store(_ValueType* __dest, _FromType __val)
+{
+    *__dest = __val;
+}
+
+template <class _ValueType>
+inline _LIBCPP_INLINE_VISIBILITY
+_ValueType __libcpp_atomic_load(_ValueType const* __val,
+                                int = 0)
+{
+    return *__val;
+}
+
+template <class _ValueType, class _AddType>
+inline _LIBCPP_INLINE_VISIBILITY
+_ValueType __libcpp_atomic_add(_ValueType* __val, _AddType __a,
+                               int = 0)
+{
+    return *__val += __a;
+}
+
+template <class _ValueType>
+inline _LIBCPP_INLINE_VISIBILITY
+_ValueType __libcpp_atomic_exchange(_ValueType* __target,
+                                    _ValueType __value, int  = _AO_Seq)
+{
+    _ValueType old = *__target;
+    *__target = __value;
+    return old;
+}
+
+template <class _ValueType>
+inline _LIBCPP_INLINE_VISIBILITY
+bool __libcpp_atomic_compare_exchange(_ValueType* __val,
+    _ValueType* __expected, _ValueType __after,
+    int = 0, int = 0)
+{
+    if (*__val == *__expected) {
+        *__val = __after;
+        return true;
+    }
+    *__expected = *__val;
+    return false;
+}
+
+#endif // _LIBCPP_HAS_NO_THREADS
+
+} // end namespace
+
+_LIBCPP_END_NAMESPACE_STD
+
+namespace {
+
+template <class IntType>
+class AtomicInt {
+public:
+  using MemoryOrder = std::__libcpp_atomic_order;
+
+  explicit AtomicInt(IntType *b) : b(b) {}
+  AtomicInt(AtomicInt const&) = delete;
+  AtomicInt& operator=(AtomicInt const&) = delete;
+
+  IntType load(MemoryOrder ord) {
+    return std::__libcpp_atomic_load(b, ord);
+  }
+  void store(IntType val, MemoryOrder ord) {
+    std::__libcpp_atomic_store(b, val, ord);
+  }
+  IntType exchange(IntType new_val, MemoryOrder ord) {
+    return std::__libcpp_atomic_exchange(b, new_val, ord);
+  }
+  bool compare_exchange(IntType *expected, IntType desired, MemoryOrder ord_success, MemoryOrder ord_failure) {
+    return std::__libcpp_atomic_compare_exchange(b, expected, desired, ord_success, ord_failure);
+  }
+
+private:
+  IntType *b;
+};
+
+} // end namespace
+
+#endif // ATOMIC_SUPPORT_H
diff --git a/lib/libcxxabi/src/include/refstring.h b/lib/libcxxabi/src/include/refstring.h
new file mode 100644
index 0000000000..5905b5c932
--- /dev/null
+++ b/lib/libcxxabi/src/include/refstring.h
@@ -0,0 +1,131 @@
+//===------------------------ __refstring ---------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// FIXME: This file is copied from libcxx/src/include/refstring.h. Instead of
+// duplicating the file in libc++abi we should require that the libc++ sources
+// are available when building libc++abi.
+
+#ifndef _LIBCPPABI_REFSTRING_H
+#define _LIBCPPABI_REFSTRING_H
+
+#include <__config>
+#include <stdexcept>
+#include <cstddef>
+#include <cstring>
+#ifdef __APPLE__
+#include <dlfcn.h>
+#include <mach-o/dyld.h>
+#endif
+#include "atomic_support.h"
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace __refstring_imp { namespace {
+typedef int count_t;
+
+struct _Rep_base {
+    std::size_t len;
+    std::size_t cap;
+    count_t     count;
+};
+
+inline _Rep_base* rep_from_data(const char *data_) noexcept {
+    char *data = const_cast<char *>(data_);
+    return reinterpret_cast<_Rep_base *>(data - sizeof(_Rep_base));
+}
+
+inline char * data_from_rep(_Rep_base *rep) noexcept {
+    char *data = reinterpret_cast<char *>(rep);
+    return data + sizeof(*rep);
+}
+
+#if defined(__APPLE__)
+inline
+const char* compute_gcc_empty_string_storage() _NOEXCEPT
+{
+    void* handle = dlopen("/usr/lib/libstdc++.6.dylib", RTLD_NOLOAD);
+    if (handle == nullptr)
+        return nullptr;
+    void* sym = dlsym(handle, "_ZNSs4_Rep20_S_empty_rep_storageE");
+    if (sym == nullptr)
+        return nullptr;
+    return data_from_rep(reinterpret_cast<_Rep_base *>(sym));
+}
+
+inline
+const char*
+get_gcc_empty_string_storage() _NOEXCEPT
+{
+    static const char* p = compute_gcc_empty_string_storage();
+    return p;
+}
+#endif
+
+}} // namespace __refstring_imp
+
+using namespace __refstring_imp;
+
+inline
+__libcpp_refstring::__libcpp_refstring(const char* msg) {
+    std::size_t len = strlen(msg);
+    _Rep_base* rep = static_cast<_Rep_base *>(::operator new(sizeof(*rep) + len + 1));
+    rep->len = len;
+    rep->cap = len;
+    rep->count = 0;
+    char *data = data_from_rep(rep);
+    std::memcpy(data, msg, len + 1);
+    __imp_ = data;
+}
+
+inline
+__libcpp_refstring::__libcpp_refstring(const __libcpp_refstring &s) _NOEXCEPT
+    : __imp_(s.__imp_)
+{
+    if (__uses_refcount())
+        __libcpp_atomic_add(&rep_from_data(__imp_)->count, 1);
+}
+
+inline
+__libcpp_refstring& __libcpp_refstring::operator=(__libcpp_refstring const& s) _NOEXCEPT {
+    bool adjust_old_count = __uses_refcount();
+    struct _Rep_base *old_rep = rep_from_data(__imp_);
+    __imp_ = s.__imp_;
+    if (__uses_refcount())
+        __libcpp_atomic_add(&rep_from_data(__imp_)->count, 1);
+    if (adjust_old_count)
+    {
+        if (__libcpp_atomic_add(&old_rep->count, count_t(-1)) < 0)
+        {
+            ::operator delete(old_rep);
+        }
+    }
+    return *this;
+}
+
+inline
+__libcpp_refstring::~__libcpp_refstring() {
+    if (__uses_refcount()) {
+        _Rep_base* rep = rep_from_data(__imp_);
+        if (__libcpp_atomic_add(&rep->count, count_t(-1)) < 0) {
+            ::operator delete(rep);
+        }
+    }
+}
+
+inline
+bool __libcpp_refstring::__uses_refcount() const {
+#ifdef __APPLE__
+    return __imp_ != get_gcc_empty_string_storage();
+#else
+    return true;
+#endif
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif //_LIBCPPABI_REFSTRING_H