/**

 * Copyright (c) Meta Platforms, Inc. and affiliates.

 *

 * This source code is licensed under the MIT license found in the

 * LICENSE file in the root directory of this source tree.

 */

#ifndef incl_HPHP_PORTABILITY_H_

#define incl_HPHP_PORTABILITY_H_

// From folly/Likely.h

#if defined(__GNUC__) && __GNUC__ >= 4

#define LIKELY(x)   (__builtin_expect((x), 1))

#define UNLIKELY(x) (__builtin_expect((x), 0))

#else

#define LIKELY(x)   (x)

#define UNLIKELY(x) (x)

#endif

//////////////////////////////////////////////////////////////////////

/*

 * Various macros to make certain things conditional on either

 * compiler or architecture.

 *

 * Currently we don't *really* compile on anything other than gcc or

 * sometimes clang, and there are some parts of the code using

 * __attribute__ stuff directly, but some things go through these

 * macros to make it maybe easier to change later.

 */

//////////////////////////////////////////////////////////////////////

// TODO: does clang define __GNUC__ ?

#ifndef __GNUC__

# define __attribute__(x)

#endif

//////////////////////////////////////////////////////////////////////

#ifdef ATTRIBUTE_UNUSED

# undef ATTRIBUTE_UNUSED

#endif

#ifdef ATTRIBUTE_NORETURN

# undef ATTRIBUTE_NORETURN

#endif

#ifdef ATTRIBUTE_PRINTF

# undef ATTRIBUTE_PRINTF

#endif

#ifdef ATTRIBUTE_PRINTF_STRING

# undef ATTRIBUTE_PRINTF_STRING

#endif

#define ATTRIBUTE_PRINTF_STRING FOLLY_PRINTF_FORMAT

#ifdef _MSC_VER

#define ATTRIBUTE_NORETURN __declspec(noreturn)

#define ATTRIBUTE_PRINTF(a1, a2)

#ifndef __thread

# define __thread __declspec(thread)

#endif

#define ATTRIBUTE_UNUSED

#define ALWAYS_INLINE __forceinline

#define EXTERNALLY_VISIBLE

#define FLATTEN

#define NEVER_INLINE __declspec(noinline)

#define UNUSED

#else

#define ATTRIBUTE_NORETURN __attribute__((__noreturn__))

#define ATTRIBUTE_PRINTF(a1, a2) \

  __attribute__((__format__ (__printf__, a1, a2)))

#define ATTRIBUTE_UNUSED   __attribute__((__unused__))

#define ALWAYS_INLINE      inline __attribute__((__always_inline__))

#define EXTERNALLY_VISIBLE __attribute__((__externally_visible__))

#define FLATTEN            __attribute__((__flatten__))

#define NEVER_INLINE       __attribute__((__noinline__))

#define UNUSED             __attribute__((__unused__))

#endif

#ifdef DEBUG

# define DEBUG_ONLY /* nop */

#else

# define DEBUG_ONLY UNUSED

#endif

/*

 * We need to keep some unreferenced functions from being removed by

 * the linker. There is no compile time mechanism for doing this, but

 * by putting them in the same section as some other, referenced function

 * in the same file, we can keep them around.

 *

 * So this macro should be used to mark at least one function that is

 * referenced, and other functions that are not referenced in the same

 * file.

 *

 * Note: this may not work properly with LTO. We'll revisit when/if we

 * move to it.

 */

#ifndef __APPLE__

# define KEEP_SECTION \

    __attribute__((__section__(".text.keep")))

#else

# define KEEP_SECTION \

    __attribute__((__section__(".text,.text.keep")))

#endif

#if defined(__APPLE__)

// OS X has a macro "isset" defined in this header. Force the include so we can

// make sure the macro gets undef'd. (I think this also applies to BSD, but we

// can cross that road when we come to it.)

# include <sys/param.h>

# ifdef isset

#  undef isset

# endif

#endif

//////////////////////////////////////////////////////////////////////

#if defined(__x86_64__)

# if defined(__clang__)

#  define DECLARE_FRAME_POINTER(fp)               \

    ActRec* fp;                                   \

    asm volatile("mov %%rbp, %0" : "=r" (fp) ::)

# else

#  define DECLARE_FRAME_POINTER(fp) register ActRec* fp asm("rbp");

# endif

#elif defined(_M_X64)

// TODO: FIXME! Without this implemented properly, the JIT

// will fail "pretty spectacularly".

# define DECLARE_FRAME_POINTER(fp) \

  always_assert(false);            \

  register ActRec* fp = nullptr;

#elif defined(__AARCH64EL__)

# if defined(__clang__)

#  error Clang implementation not done for ARM

# endif

# define DECLARE_FRAME_POINTER(fp) register ActRec* fp asm("x29");

#elif defined(__powerpc64__)

# if defined(__clang__)

#  error Clang implementation not done for PPC64

# endif

# define DECLARE_FRAME_POINTER(fp) register ActRec* fp = (ActRec*) __builtin_frame_address(0);

#else

# error What are the stack and frame pointers called on your architecture?

#endif

//////////////////////////////////////////////////////////////////////

// We reserve the exit status 127 to signal a failure in the

// interpreter. 127 is a valid exit code on all reasonable

// architectures: POSIX requires at least 8 unsigned bits and

// Windows 32 signed bits.

#define HPHP_EXIT_FAILURE 127

//////////////////////////////////////////////////////////////////////

#if FACEBOOK

// Linking in libbfd is a gigantic PITA. If you want this yourself in a non-FB

// build, feel free to define HAVE_LIBBFD and specify the right options to link

// in libbfd.a in the extra C++ options.

#define HAVE_LIBBFD 1

#endif

#ifndef PACKAGE

// The value doesn't matter, but it must be defined before you include

// bfd.h

#define PACKAGE "hhvm"

#endif

//////////////////////////////////////////////////////////////////////

#endif