Add check for __builtin_addressof

lackhole · Aug 2, 2024 · 27aea9e · 27aea9e
1 parent 80383d1
commit 27aea9e
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Showing 12 changed files with 121 additions and 50 deletions.
diff --git a/cmake/RunConfiguration.cmake b/cmake/RunConfiguration.cmake
@@ -2,12 +2,14 @@ include(CheckCXXSourceCompiles)
 include(CheckCXXCompilerFlag)
 include(CheckCXXSymbolExists)
 
+include(config/HaveConstexprBuiltinAddressof)
 include(config/HaveContiguousIteratorTag)
 include(config/HaveStringView)
 
 set(PREVIEW_CONFIG_INPUT_FILE "${PREVIEW_INCLUDE_DIR}/preview/cmake_config.h.in")
 
 function(RunConfiguration out_dir flags)
+    HaveConstexprBuiltinAddressof(PREVIEW_HAVE_CONSTEXPR_BUILTIN_ADDRESSOF ${flags})
     HaveContiguousIteratorTag(PREVIEW_HAVE_CONTIGUOUS_ITERATOR_TAG ${flags})
     HaveStringView(PREVIEW_HAVE_STRING_VIEW ${flags})
 

diff --git a/cmake/config/HaveConstexprBuiltinAddressof.cmake b/cmake/config/HaveConstexprBuiltinAddressof.cmake
@@ -0,0 +1,11 @@
+set(HaveConstexprBuiltinAddressof_Source "
+constexpr int x = 0;
+constexpr auto ptr = __builtin_addressof(x);
+static_assert(ptr == &x, \"\");
+int main() { return 0; }")
+
+function(HaveConstexprBuiltinAddressof out)
+    set(CMAKE_REQUIRED_FLAGS ${ARGN})
+    check_cxx_source_compiles("${HaveConstexprBuiltinAddressof_Source}" ${out})
+    set(${out} ${${out}} PARENT_SCOPE)
+endfunction()
diff --git a/include/preview/__expected/expected.h b/include/preview/__expected/expected.h
@@ -1066,34 +1066,34 @@ class expected : private detail::expected_control_smf<detail::void_placdholder_o
   template<typename Any>
   static PREVIEW_CONSTEXPR_AFTER_CXX17
   void swap_value_with_error(expected& thiz, expected& other, std::true_type /* void */, Any) noexcept(error_nothrow_swappable::value) {
-    preview::construct_at(std::addressof(thiz.error()), std::move(other.error()));
-    preview::destroy_at(std::addressof(other.error()));
+    preview::construct_at(preview::addressof(thiz.error()), std::move(other.error()));
+    preview::destroy_at(preview::addressof(other.error()));
   }
 
   static PREVIEW_CONSTEXPR_AFTER_CXX23
   void swap_value_with_error(expected& thiz, expected& other, std::false_type /* void */, std::true_type /* nothrow */) noexcept(nothrow_swappable::value) {
     E temp(std::move(other.error()));
-    preview::destroy_at(std::addressof(other.error()));
+    preview::destroy_at(preview::addressof(other.error()));
     try {
-      preview::construct_at(std::addressof(other.value()), std::move(thiz.value()));
-      preview::destroy_at(std::addressof(thiz.value()));
-      preview::construct_at(std::addressof(thiz.error()), std::move(temp));
+      preview::construct_at(preview::addressof(other.value()), std::move(thiz.value()));
+      preview::destroy_at(preview::addressof(thiz.value()));
+      preview::construct_at(preview::addressof(thiz.error()), std::move(temp));
     } catch (...) {
-      preview::construct_at(std::addressof(other.error()), std::move(temp));
+      preview::construct_at(preview::addressof(other.error()), std::move(temp));
       throw;
     }
   }
 
   static PREVIEW_CONSTEXPR_AFTER_CXX23
   void swap_value_with_error(expected& thiz, expected& other, std::false_type /* void */, std::false_type /* nothrow */) noexcept(nothrow_swappable::value) {
     T temp(std::move(thiz.value()));
-    preview::destroy_at(std::addressof(thiz.value()));
+    preview::destroy_at(preview::addressof(thiz.value()));
     try {
-      preview::construct_at(std::addressof(thiz.error()), std::move(other.error()));
-      preview::destroy_at(std::addressof(other.error()));
-      preview::construct_at(std::addressof(other.value()), std::move(temp));
+      preview::construct_at(preview::addressof(thiz.error()), std::move(other.error()));
+      preview::destroy_at(preview::addressof(other.error()));
+      preview::construct_at(preview::addressof(other.value()), std::move(temp));
     } catch (...) {
-      preview::construct_at(std::addressof(thiz.value()), std::move(temp));
+      preview::construct_at(preview::addressof(thiz.value()), std::move(temp));
       throw;
     }
   }

diff --git a/include/preview/__memory/addressof.h b/include/preview/__memory/addressof.h
@@ -8,36 +8,71 @@
 #include <memory>
 #include <type_traits>
 
+#include "preview/core.h"
+#include "preview/config.h"
+#include "preview/__type_traits/void_t.h"
+
 namespace preview {
+namespace detail {
+
+PREVIEW_INLINE_VARIABLE constexpr int builtin_addressof_tester{};
+
+template<typename = void>
+struct have_builtin_addressof : std::false_type {};
+
+template<>
+struct have_builtin_addressof<
+    void_t<
+        decltype(std::integral_constant<
+            bool,
+            (&builtin_addressof_tester == __builtin_addressof(builtin_addressof_tester))
+        >{})
+    >
+> : std::true_type {};
 
-# if __cplusplus < 201703L
-#  ifdef PREVIEW_CONSTEXPR_BUILTIN_ADDRESSOF_CXX14
 template<typename T>
-constexpr T* addressof(T& t) noexcept {
+constexpr T* addressof_object(T& t, std::true_type) noexcept {
   return __builtin_addressof(t);
 }
-#  else
+
 template<typename T>
-std::enable_if_t<std::is_object<T>::value, T*>
-addressof(T& t) noexcept {
-  return
-    reinterpret_cast<T*>(
+T* addressof_object(T& t, std::false_type) noexcept {
+  return reinterpret_cast<T*>(
       &const_cast<char&>(
-        reinterpret_cast<const volatile char&>(t)
+          reinterpret_cast<const volatile char&>(t)
       )
-    );
+  );
 }
+
+template<typename T>
+constexpr T* addressof_impl(T& t, std::true_type /* is_object */) noexcept {
+  return preview::detail::addressof_object(t, have_builtin_addressof<>{});
+}
+
 template<typename T>
-constexpr std::enable_if_t<std::is_object<T>::value == false, T*>
-addressof(T& t) noexcept {
+constexpr T* addressof_impl(T& t, std::false_type /* is_object */) noexcept {
   return &t;
 }
-#  endif
-# else
+
+} // namespace detail
+
+# if PREVIEW_CXX_VERSION >= 17
 template<typename T>
 constexpr T* addressof(T& t) noexcept {
   return std::addressof(t);
 }
+# else
+#  if PREVIEW_HAVE_CONSTEXPR_BUILTIN_ADDRESSOF
+template<typename T>
+constexpr T* addressof(T& t) noexcept {
+  return __builtin_addressof(t);
+}
+#  else
+template<typename T>
+constexpr T* addressof(T& t) noexcept {
+  return preview::detail::addressof_impl(t, std::is_object<T>{});
+}
+#  endif
 # endif
 
 template<typename T>

diff --git a/include/preview/__optional/optional.h b/include/preview/__optional/optional.h
@@ -14,6 +14,7 @@
 # include "preview/__concepts/invocable.h"
 # include "preview/__concepts/move_constructible.h"
 # include "preview/__functional/invoke.h"
+# include "preview/__memory/addressof.h"
 # include "preview/__memory/construct_at.h"
 # include "preview/__memory/destroy_at.h"
 # include "preview/__optional/bad_optional_access.h"
@@ -84,13 +85,13 @@ struct optional_base {
 
   void reset() {
     if (storage_.has_value) {
-      preview::destroy_at(std::addressof(storage_.value));
+      preview::destroy_at(preview::addressof(storage_.value));
       storage_.has_value = false;
     }
   }
 
-  PREVIEW_CONSTEXPR_AFTER_CXX17 const value_type* operator->() const noexcept { return std::addressof(storage_.value); }
-  PREVIEW_CONSTEXPR_AFTER_CXX17       value_type* operator->()       noexcept { return std::addressof(storage_.value); }
+  PREVIEW_CONSTEXPR_AFTER_CXX17 const value_type* operator->() const noexcept { return preview::addressof(storage_.value); }
+  PREVIEW_CONSTEXPR_AFTER_CXX17       value_type* operator->()       noexcept { return preview::addressof(storage_.value); }
 
   constexpr const value_type&  operator*() const&  noexcept { return storage_.value;             }
   constexpr       value_type&  operator*()      &  noexcept { return storage_.value;             }
@@ -168,13 +169,13 @@ struct optional_base {
 
   template<typename ...Args>
   void construct_with(Args&&... args) {
-    preview::construct_at(std::addressof(storage_.value), std::forward<Args>(args)...);
+    preview::construct_at(preview::addressof(storage_.value), std::forward<Args>(args)...);
     storage_.has_value = true;
   }
 
   void destruct() {
     if (has_value())
-      preview::destroy_at(std::addressof(storage_.value));
+      preview::destroy_at(preview::addressof(storage_.value));
   }
 
  private:

diff --git a/include/preview/__ranges/views/basic_istream_view.h b/include/preview/__ranges/views/basic_istream_view.h
@@ -107,7 +107,7 @@ class basic_istream_view : public view_interface<basic_istream_view<Val, CharT,
 
 
   PREVIEW_CONSTEXPR_AFTER_CXX17 explicit basic_istream_view(std::basic_istream<CharT, Traits>& stream)
-      : stream_(std::addressof(stream)), value_() {}
+      : stream_(preview::addressof(stream)), value_() {}
 
   constexpr auto begin() {
     read();

diff --git a/include/preview/__ranges/views/lazy_split_view.h b/include/preview/__ranges/views/lazy_split_view.h
@@ -24,14 +24,14 @@
 #include "preview/__iterator/iterator_tag.h"
 #include "preview/__iterator/iterator_traits.h"
 #include "preview/__iterator/detail/have_cxx20_iterator.h"
+#include "preview/__memory/addressof.h"
 #include "preview/__ranges/begin.h"
 #include "preview/__ranges/end.h"
 #include "preview/__ranges/forward_range.h"
 #include "preview/__ranges/input_range.h"
 #include "preview/__ranges/iterator_t.h"
 #include "preview/__ranges/non_propagating_cache.h"
 #include "preview/__ranges/range_difference_t.h"
-//#include "preview/__ranges/range_reference_t.h"
 #include "preview/__ranges/range_value_t.h"
 #include "preview/__ranges/simple_view.h"
 #include "preview/__ranges/sized_range.h"
@@ -136,13 +136,13 @@ class lazy_split_view
         negation<forward_range<Base>>
     >::value, int> = 0>
     PREVIEW_CONSTEXPR_AFTER_CXX17 explicit outer_iterator(Parent& parent)
-        : parent_(std::addressof(parent)) {}
+        : parent_(preview::addressof(parent)) {}
 
     template<typename Dummy = void, std::enable_if_t<conjunction<std::is_void<Dummy>,
         forward_range<Base>
     >::value, int> = 0>
     PREVIEW_CONSTEXPR_AFTER_CXX17 explicit outer_iterator(Parent& parent, iterator_t<Base> current)
-        : parent_(std::addressof(parent))
+        : parent_(preview::addressof(parent))
         , current_(std::move(current)) {}
 
     template<bool AntiConst, std::enable_if_t<conjunction<

diff --git a/include/preview/__ranges/views/take_while_view.h b/include/preview/__ranges/views/take_while_view.h
@@ -14,6 +14,7 @@
 #include "preview/__concepts/copy_constructible.h"
 #include "preview/__functional/invoke.h"
 #include "preview/__iterator/indirect_unary_predicate.h"
+#include "preview/__memory/addressof.h"
 #include "preview/__ranges/begin.h"
 #include "preview/__ranges/input_range.h"
 #include "preview/__ranges/iterator_t.h"
@@ -157,15 +158,15 @@ class take_while_view : public view_interface<take_while_view<V, Pred>> {
       negation<simple_view<V>>
   >::value, int> = 0>
   PREVIEW_CONSTEXPR_AFTER_CXX17 auto end() {
-    return sentinel<false>{ranges::end(base_), std::addressof(*pred_)};
+    return sentinel<false>{ranges::end(base_), preview::addressof(*pred_)};
   }
 
   template<typename Dummy = void, std::enable_if_t<preview::conjunction<std::is_void<Dummy>,
       range<const V>,
       indirect_unary_predicate<const Pred, iterator_t<const V>>
   >::value, int> = 0>
   PREVIEW_CONSTEXPR_AFTER_CXX17 auto end() const {
-    return sentinel<true>{ranges::end(base_), std::addressof(*pred_)};
+    return sentinel<true>{ranges::end(base_), preview::addressof(*pred_)};
   }
 
  private:

diff --git a/include/preview/__ranges/views/zip_transform_view.h b/include/preview/__ranges/views/zip_transform_view.h
@@ -21,6 +21,7 @@
 #include "preview/__iterator/iterator_tag.h"
 #include "preview/__iterator/iterator_traits.h"
 #include "preview/__iterator/sized_sentinel_for.h"
+#include "preview/__memory/addressof.h"
 #include "preview/__ranges/bidirectional_range.h"
 #include "preview/__ranges/forward_range.h"
 #include "preview/__ranges/input_range.h"
@@ -286,7 +287,7 @@ class zip_transform_view : public view_interface<zip_transform_view<Views...>> {
 
    private:
     PREVIEW_CONSTEXPR_AFTER_CXX17 iterator(Parent& parent, ziperator<Const> inner)
-        : parent_(std::addressof(parent)), inner_(std::move(inner)) {}
+        : parent_(preview::addressof(parent)), inner_(std::move(inner)) {}
 
     Parent* parent_{};
     ziperator<Const> inner_{};

diff --git a/include/preview/cmake_config.h.in b/include/preview/cmake_config.h.in
@@ -5,14 +5,16 @@
 
 #ifdef PREVIEW_CMAKE_CONFIG
 
+#cmakedefine01 PREVIEW_HAVE_CONSTEXPR_BUILTIN_ADDRESSOF
 #cmakedefine01 PREVIEW_HAVE_STRING_VIEW
 #cmakedefine01 PREVIEW_HAVE_CONTIGUOUS_ITERATOR_TAG
 
 #else
 
 #include "preview/core.h"
 
-#define PREVIEW_HAVE_STRING_VIEW             (PREVIEW_CXX_VERSION >= 17)
-#define PREVIEW_HAVE_CONTIGUOUS_ITERATOR_TAG (PREVIEW_CXX_VERSION >= 20)
+#define PREVIEW_HAVE_CONSTEXPR_BUILTIN_ADDRESSOF (PREVIEW_CXX_VERSION >= 17)
+#define PREVIEW_HAVE_CONTIGUOUS_ITERATOR_TAG     (PREVIEW_CXX_VERSION >= 20)
+#define PREVIEW_HAVE_STRING_VIEW                 (PREVIEW_CXX_VERSION >= 17)
 
 #endif
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
@@ -183,7 +183,6 @@ function(preview_add_multi_version_test name_prefix test_src)
             BUILD_COMMAND ""
             INSTALL_COMMAND ""
             BUILD_BYPRODUCTS
-                "<BINARY_DIR>/${PREVIEW_RELATIVE_GENERATED_INCLUDE_DIR}"
                 "<BINARY_DIR>/${PREVIEW_RELATIVE_GENERATED_INCLUDE_DIR}/preview/cmake_config.h"
         )
         add_dependencies(${target_name} preview-configure-${target_name})

diff --git a/test/memory.cc b/test/memory.cc
@@ -1,6 +1,28 @@
 #include "preview/memory.h"
 #include "gtest.h"
 
+struct bizarre_object {
+  int operator&() const {
+    return 3;
+  }
+};
+
+constexpr int global_y = 4;
+TEST(VERSIONED(Memory), addressof) {
+
+  int x = 3;
+  EXPECT_EQ(&x, preview::addressof(x));
+
+  bizarre_object obj;
+  EXPECT_EQ_TYPE(int, decltype(&obj));
+  EXPECT_EQ_TYPE(bizarre_object*, decltype(preview::addressof(obj)));
+
+#if PREVIEW_CXX_VERSION >= 17
+  constexpr auto ptr = preview::addressof(global_y);
+  (void)ptr;
+#endif
+}
+
 class S
 {
   int x_;
@@ -18,13 +40,10 @@ class S
 };
 
 TEST(VERSIONED(Memory), construct_at) {
-
-
-
-  alignas(S) unsigned char storage[sizeof(S)]{};
-  S uninitialized = std::bit_cast<S>(storage);
-  std::destroy_at(&uninitialized);
-  S* ptr = std::construct_at(std::addressof(uninitialized), 42, 2.71f, 3.14);
-  const bool res{*ptr == S{42, 2.71f, 3.14}};
-  std::destroy_at(ptr);
+//  alignas(S) unsigned char storage[sizeof(S)]{};
+//  S uninitialized = std::bit_cast<S>(storage);
+//  std::destroy_at(&uninitialized);
+//  S* ptr = std::construct_at(std::addressof(uninitialized), 42, 2.71f, 3.14);
+//  const bool res{*ptr == S{42, 2.71f, 3.14}};
+//  std::destroy_at(ptr);
 }