Add folly::Expected, an alternative to exceptions for non-throwing APIs that can...

[folly.git] / folly / Portability.h

diff --git a/folly/Portability.h b/folly/Portability.h
index 363fe3041018aaf9ee493130e88dbdad7be52a05..56dc7c95c2a59c1994f2cde035518a1f512c8374 100644 (file)
--- a/folly/Portability.h
+++ b/folly/Portability.h
@@ -14,8 +14,7 @@
  * limitations under the License.
  */
 
-#ifndef FOLLY_PORTABILITY_H_
-#define FOLLY_PORTABILITY_H_
+#pragma once
 
 #include <string.h>
 
@@ -25,10 +24,6 @@
 
 #include <folly/CPortability.h>
 
-#ifdef __APPLE__
-# include <malloc/malloc.h>
-#endif
-
 #if FOLLY_HAVE_SCHED_H
  #include <sched.h>
 #endif
@@ -79,15 +74,6 @@ constexpr bool kHasUnalignedAccess = false;
 # define FOLLY_DEPRECATED(msg)
 #endif
 
-// noreturn
-#if defined(_MSC_VER)
-# define FOLLY_NORETURN __declspec(noreturn)
-#elif defined(__clang__) || defined(__GNUC__)
-# define FOLLY_NORETURN __attribute__((__noreturn__))
-#else
-# define FOLLY_NORETURN
-#endif
-
 // noinline
 #ifdef _MSC_VER
 # define FOLLY_NOINLINE __declspec(noinline)
@@ -106,6 +92,13 @@ constexpr bool kHasUnalignedAccess = false;
 # define FOLLY_ALWAYS_INLINE inline
 #endif
 
+// target
+#ifdef _MSC_VER
+# define FOLLY_TARGET_ATTRIBUTE(target)
+#else
+# define FOLLY_TARGET_ATTRIBUTE(target) __attribute__((__target__(target)))
+#endif
+
 // detection for 64 bit
 #if defined(__x86_64__) || defined(_M_X64)
 # define FOLLY_X64 1
@@ -214,16 +207,6 @@ namespace std { typedef ::max_align_t max_align_t; }
 #undef FOLLY_TLS
 #endif
 
-// Define to 1 if you have the `preadv' and `pwritev' functions, respectively
-#if !defined(FOLLY_HAVE_PREADV) && !defined(FOLLY_HAVE_PWRITEV)
-# if defined(__GLIBC_PREREQ)
-#  if __GLIBC_PREREQ(2, 10)
-#   define FOLLY_HAVE_PREADV 1
-#   define FOLLY_HAVE_PWRITEV 1
-#  endif
-# endif
-#endif
-
 // It turns out that GNU libstdc++ and LLVM libc++ differ on how they implement
 // the 'std' namespace; the latter uses inline namespaces. Wrap this decision
 // up in a macro to make forward-declarations easier.
@@ -246,14 +229,6 @@ namespace std { typedef ::max_align_t max_align_t; }
 # define FOLLY_GLIBCXX_NAMESPACE_CXX11_END
 #endif
 
-// Some platforms lack clock_gettime(2) and clock_getres(2). Inject our own
-// versions of these into the global namespace.
-#if FOLLY_HAVE_CLOCK_GETTIME
-#include <time.h>
-#else
-#include <folly/detail/Clock.h>
-#endif
-
 // Provide our own std::__throw_* wrappers for platforms that don't have them
 #if FOLLY_HAVE_BITS_FUNCTEXCEPT_H
 #include <bits/functexcept.h>
@@ -288,13 +263,6 @@ namespace std { typedef ::max_align_t max_align_t; }
 #ifdef _MSC_VER
 #include <folly/portability/SysTypes.h>
 
-// sprintf semantics are not exactly identical
-// but current usage is not a problem
-# define snprintf _snprintf
-
-// semantics here are identical
-# define strerror_r(errno,buf,len) strerror_s(buf,len,errno)
-
 // compiler specific to compiler specific
 // nolint
 # define __PRETTY_FUNCTION__ __FUNCSIG__
@@ -302,10 +270,9 @@ namespace std { typedef ::max_align_t max_align_t; }
 // Hide a GCC specific thing that breaks MSVC if left alone.
 # define __extension__
 
-#ifdef _M_IX86_FP
-# define FOLLY_SSE _M_IX86_FP
-# define FOLLY_SSE_MINOR 0
-#endif
+// We have compiler support for the newest of the new, but
+// MSVC doesn't tell us that.
+#define __SSE4_2__ 1
 
 #endif
 
@@ -373,64 +340,26 @@ using namespace FOLLY_GFLAGS_NAMESPACE;
 #include <TargetConditionals.h>
 #endif
 
-// MacOS doesn't have malloc_usable_size()
-#if defined(__APPLE__) && !defined(FOLLY_HAVE_MALLOC_USABLE_SIZE)
-inline size_t malloc_usable_size(void* ptr) {
-  return malloc_size(ptr);
-}
-#endif
-
 // RTTI may not be enabled for this compilation unit.
 #if defined(__GXX_RTTI) || defined(__cpp_rtti) || \
     (defined(_MSC_VER) && defined(_CPPRTTI))
 # define FOLLY_HAS_RTTI 1
 #endif
 
-#ifdef _MSC_VER
-# include <intrin.h>
-#endif
-
-namespace folly {
-
-inline void asm_volatile_memory() {
-#if defined(__clang__) || defined(__GNUC__)
-  asm volatile("" : : : "memory");
-#elif defined(_MSC_VER)
-  ::_ReadWriteBarrier();
-#endif
-}
-
-inline void asm_volatile_pause() {
-#if defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_X64))
-  ::_mm_pause();
-#elif defined(__i386__) || FOLLY_X64
-  asm volatile ("pause");
-#elif FOLLY_A64 || defined(__arm__)
-  asm volatile ("yield");
-#elif FOLLY_PPC64
-  asm volatile("or 27,27,27");
-#endif
-}
-inline void asm_pause() {
-#if defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_X64))
-  ::_mm_pause();
-#elif defined(__i386__) || FOLLY_X64
-  asm ("pause");
-#elif FOLLY_A64 || defined(__arm__)
-  asm ("yield");
-#elif FOLLY_PPC64
-  asm ("or 31,31,31");
-#endif
-}
-
 #if defined(__APPLE__) || defined(_MSC_VER)
-#define MAX_STATIC_CONSTRUCTOR_PRIORITY
+#define FOLLY_STATIC_CTOR_PRIORITY_MAX
 #else
 // 101 is the highest priority allowed by the init_priority attribute.
 // This priority is already used by JEMalloc and other memory allocators so
 // we will take the next one.
-#define MAX_STATIC_CONSTRUCTOR_PRIORITY __attribute__ ((__init_priority__(102)))
+#define FOLLY_STATIC_CTOR_PRIORITY_MAX __attribute__((__init_priority__(102)))
 #endif
 
-} // namespace folly
-#endif // FOLLY_PORTABILITY_H_
+namespace folly {
+
+#if defined(__linux__) && !FOLLY_MOBILE
+constexpr auto kIsLinux = true;
+#else
+constexpr auto kIsLinux = false;
+#endif
+}