X-Git-Url: http://plrg.eecs.uci.edu/git/?p=folly.git;a=blobdiff_plain;f=folly%2FPortability.h;h=3831f04d43580d5601cb8919be6c5952af891221;hp=04d1848dcfce923a14f123e9c676a66c2155e445;hb=b22d1721ed9c062e22b33936e13b39ed1507391a;hpb=20408f9aaf64d7b89eb790abb0ade993553289ff

diff --git a/folly/Portability.h b/folly/Portability.h
index 04d1848d..3831f04d 100644
--- a/folly/Portability.h
+++ b/folly/Portability.h
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Facebook, Inc.
+ * Copyright 2017-present Facebook, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,10 +16,7 @@
 
 #pragma once
 
-#include <string.h>
-
 #include <cstddef>
-#include <type_traits>
 
 #include <folly/portability/Config.h>
 
@@ -32,87 +29,11 @@ constexpr bool kHasUnalignedAccess = true;
 #else
 constexpr bool kHasUnalignedAccess = false;
 #endif
-
-namespace portability_detail {
-
-template <typename I, I A, I B>
-using integral_max = std::integral_constant<I, (A < B) ? B : A>;
-
-template <typename I, I A, I... Bs>
-struct integral_sequence_max
-    : integral_max<I, A, integral_sequence_max<I, Bs...>::value> {};
-
-template <typename I, I A>
-struct integral_sequence_max<I, A> : std::integral_constant<I, A> {};
-
-template <typename... Ts>
-using max_alignment = integral_sequence_max<size_t, alignof(Ts)...>;
-
-using max_basic_alignment = max_alignment<
-    std::max_align_t,
-    long double,
-    double,
-    float,
-    long long int,
-    long int,
-    int,
-    short int,
-    bool,
-    char,
-    char16_t,
-    char32_t,
-    wchar_t,
-    std::nullptr_t>;
-} // namespace detail
-
-constexpr size_t max_align_v = portability_detail::max_basic_alignment::value;
-
-// max_align_t is a type which is aligned at least as strictly as the
-// most-aligned basic type (see the specification of std::max_align_t). This
-// implementation exists because 32-bit iOS platforms have a broken
-// std::max_align_t (see below).
-//
-// You should refer to this as `::folly::max_align_t` in portable code, even if
-// you have `using namespace folly;` because C11 defines a global namespace
-// `max_align_t` type.
-//
-// To be certain, we consider every non-void fundamental type specified by the
-// standard. On most platforms `long double` would be enough, but iOS 32-bit
-// has an 8-byte aligned `double` and `long long int` and a 4-byte aligned
-// `long double`.
-//
-// So far we've covered locals and other non-allocated storage, but we also need
-// confidence that allocated storage from `malloc`, `new`, etc will also be
-// suitable for objects with this alignment reuirement.
-//
-// Apple document that their implementation of malloc will issue 16-byte
-// granularity chunks for small allocations (large allocations are page-size
-// granularity and page-aligned). We think that allocated storage will be
-// suitable for these objects based on the following assumptions:
-//
-// 1. 16-byte granularity also means 16-byte aligned.
-// 2. `new` and other allocators follow the `malloc` rules.
-//
-// We also have some anecdotal evidence: we don't see lots of misaligned-storage
-// crashes on 32-bit iOS apps that use `double`.
-//
-// Apple's allocation reference: http://bit.ly/malloc-small
-struct alignas(max_align_v) max_align_t {};
-
 } // namespace folly
 
 // compiler specific attribute translation
 // msvc should come first, so if clang is in msvc mode it gets the right defines
 
-#if defined(__clang__) || defined(__GNUC__)
-# define FOLLY_ALIGNED(size) __attribute__((__aligned__(size)))
-#elif defined(_MSC_VER)
-# define FOLLY_ALIGNED(size) __declspec(align(size))
-#else
-# error Cannot define FOLLY_ALIGNED on this platform
-#endif
-#define FOLLY_ALIGNED_MAX FOLLY_ALIGNED(::folly::max_align_v)
-
 // NOTE: this will only do checking in msvc with versions that support /analyze
 #if _MSC_VER
 # ifdef _USE_ATTRIBUTES_FOR_SAL
@@ -168,10 +89,16 @@ struct alignas(max_align_v) max_align_t {};
 # define FOLLY_X64 0
 #endif
 
+#if defined(__arm__)
+#define FOLLY_ARM 1
+#else
+#define FOLLY_ARM 0
+#endif
+
 #if defined(__aarch64__)
-# define FOLLY_A64 1
+# define FOLLY_AARCH64 1
 #else
-# define FOLLY_A64 0
+# define FOLLY_AARCH64 0
 #endif
 
 #if defined (__powerpc64__)
@@ -181,10 +108,11 @@ struct alignas(max_align_v) max_align_t {};
 #endif
 
 namespace folly {
+constexpr bool kIsArchArm = FOLLY_ARM == 1;
 constexpr bool kIsArchAmd64 = FOLLY_X64 == 1;
-constexpr bool kIsArchAArch64 = FOLLY_A64 == 1;
+constexpr bool kIsArchAArch64 = FOLLY_AARCH64 == 1;
 constexpr bool kIsArchPPC64 = FOLLY_PPC64 == 1;
-}
+} // namespace folly
 
 namespace folly {
 
@@ -199,7 +127,13 @@ constexpr bool kIsSanitizeThread = true;
 #else
 constexpr bool kIsSanitizeThread = false;
 #endif
-}
+
+#if FOLLY_SANITIZE
+constexpr bool kIsSanitize = true;
+#else
+constexpr bool kIsSanitize = false;
+#endif
+} // namespace folly
 
 // packing is very ugly in msvc
 #ifdef _MSC_VER
@@ -247,18 +181,6 @@ constexpr bool kIsSanitizeThread = false;
 #define FOLLY_GCC_DISABLE_NEW_SHADOW_WARNINGS /* empty */
 #endif
 
-// portable version check for clang
-#ifndef __CLANG_PREREQ
-# if defined __clang__ && defined __clang_major__ && defined __clang_minor__
-/* nolint */
-#  define __CLANG_PREREQ(maj, min) \
-    ((__clang_major__ << 16) + __clang_minor__ >= ((maj) << 16) + (min))
-# else
-/* nolint */
-#  define __CLANG_PREREQ(maj, min) 0
-# endif
-#endif
-
 /* Platform specific TLS support
  * gcc implements __thread
  * msvc implements __declspec(thread)
@@ -325,7 +247,7 @@ constexpr auto kIsDebug = false;
 #else
 constexpr auto kIsDebug = true;
 #endif
-}
+} // namespace folly
 
 // Endianness
 namespace folly {
@@ -340,7 +262,7 @@ constexpr auto kIsLittleEndian = true;
 constexpr auto kIsLittleEndian = __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__;
 #endif
 constexpr auto kIsBigEndian = !kIsLittleEndian;
-}
+} // namespace folly
 
 #ifndef FOLLY_SSE
 # if defined(__SSE4_2__)
@@ -374,7 +296,7 @@ constexpr auto kIsBigEndian = !kIsLittleEndian;
 namespace FOLLY_GFLAGS_NAMESPACE { }
 namespace gflags {
 using namespace FOLLY_GFLAGS_NAMESPACE;
-}  // namespace gflags
+} // namespace gflags
 #endif
 
 // for TARGET_OS_IPHONE
@@ -405,6 +327,12 @@ constexpr auto kIsObjC = true;
 constexpr auto kIsObjC = false;
 #endif
 
+#if FOLLY_MOBILE
+constexpr auto kIsMobile = true;
+#else
+constexpr auto kIsMobile = false;
+#endif
+
 #if defined(__linux__) && !FOLLY_MOBILE
 constexpr auto kIsLinux = true;
 #else
@@ -418,4 +346,33 @@ constexpr auto kMscVer = _MSC_VER;
 constexpr auto kIsWindows = false;
 constexpr auto kMscVer = 0;
 #endif
-}
+} // namespace folly
+
+// Define FOLLY_USE_CPP14_CONSTEXPR to be true if the compiler's C++14
+// constexpr support is "good enough".
+#ifndef FOLLY_USE_CPP14_CONSTEXPR
+#if defined(__clang__)
+#define FOLLY_USE_CPP14_CONSTEXPR __cplusplus >= 201300L
+#elif defined(__GNUC__)
+#define FOLLY_USE_CPP14_CONSTEXPR __cplusplus >= 201304L
+#else
+#define FOLLY_USE_CPP14_CONSTEXPR 0 // MSVC?
+#endif
+#endif
+
+#if FOLLY_USE_CPP14_CONSTEXPR
+#define FOLLY_CPP14_CONSTEXPR constexpr
+#else
+#define FOLLY_CPP14_CONSTEXPR inline
+#endif
+
+#if __cpp_coroutines >= 201703L && FOLLY_HAS_INCLUDE(<experimental/coroutine>)
+#define FOLLY_HAS_COROUTINES 1
+#elif _MSC_VER && _RESUMABLE_FUNCTIONS_SUPPORTED
+#define FOLLY_HAS_COROUTINES 1
+#endif
+
+// MSVC 2017.5
+#if __cpp_noexcept_function_type >= 201510 || _MSC_FULL_VER >= 191225816
+#define FOLLY_HAVE_NOEXCEPT_FUNCTION_TYPE 1
+#endif