hphp/util/portability.h

   1 /*
   2    +----------------------------------------------------------------------+
   3    | HipHop for PHP                                                       |
   4    +----------------------------------------------------------------------+
   5    | Copyright (c) 2010-present Facebook, Inc. (http://www.facebook.com)  |
   6    +----------------------------------------------------------------------+
   7    | This source file is subject to version 3.01 of the PHP license,      |
   8    | that is bundled with this package in the file LICENSE, and is        |
   9    | available through the world-wide-web at the following url:           |
  10    | http://www.php.net/license/3_01.txt                                  |
  11    | If you did not receive a copy of the PHP license and are unable to   |
  12    | obtain it through the world-wide-web, please send a note to          |
  13    | license@php.net so we can mail you a copy immediately.               |
  14    +----------------------------------------------------------------------+
  15 */
  16 #pragma once
  17
  18 #if !defined(NO_FOLLY)
  19 #include <folly/Likely.h> // defining LIKELY/UNLIKELY is part of this header
  20 #include <folly/Portability.h>
  21 #include <folly/CPortability.h> // FOLLY_DISABLE_ADDRESS_SANITIZER, FOLLY_EXPORT
  22 #endif
  23
  24 //////////////////////////////////////////////////////////////////////
  25
  26 /*
  27  * Various macros to make certain things conditional on either
  28  * compiler or architecture.
  29  *
  30  * Currently we don't *really* compile on anything other than gcc or
  31  * sometimes clang, and there are some parts of the code using
  32  * __attribute__ stuff directly, but some things go through these
  33  * macros to make it maybe easier to change later.
  34  */
  35
  36 //////////////////////////////////////////////////////////////////////
  37
  38 // TODO: does clang define __GNUC__ ?
  39 #ifndef __GNUC__
  40 # define __attribute__(x)
  41 #endif
  42
  43 //////////////////////////////////////////////////////////////////////
  44
  45 #ifdef ATTRIBUTE_UNUSED
  46 # undef ATTRIBUTE_UNUSED
  47 #endif
  48 #ifdef ATTRIBUTE_PRINTF
  49 # undef ATTRIBUTE_PRINTF
  50 #endif
  51 #ifdef ATTRIBUTE_PRINTF_STRING
  52 # undef ATTRIBUTE_PRINTF_STRING
  53 #endif
  54
  55 #ifdef FOLLY_PRINTF_FORMAT
  56 #define ATTRIBUTE_PRINTF_STRING FOLLY_PRINTF_FORMAT
  57 #else
  58 #define ATTRIBUTE_PRINTF_STRING
  59 #endif
  60
  61 #define ATTRIBUTE_PRINTF(a1, a2) \
  62   __attribute__((__format__ (__printf__, a1, a2)))
  63 #define ATTRIBUTE_UNUSED   __attribute__((__unused__))
  64 #define ATTRIBUTE_USED     __attribute__((__used__))
  65 #ifndef NDEBUG
  66 # define FLATTEN           /*nop*/
  67 # define ALWAYS_INLINE     inline
  68 # define INLINE_FLATTEN    inline
  69 #else
  70 # define FLATTEN           __attribute__((__flatten__))
  71 # define ALWAYS_INLINE     inline __attribute__((__always_inline__))
  72 # define INLINE_FLATTEN    inline __attribute__((__always_inline__,__flatten__))
  73 #endif
  74 #define NEVER_INLINE       __attribute__((__noinline__))
  75 #define UNUSED             __attribute__((__unused__))
  76
  77 #ifdef __clang__
  78 #define NO_OPT [[clang::optnone]]
  79 #define EXTERNALLY_VISIBLE ATTRIBUTE_USED FOLLY_EXPORT
  80 #else
  81 #define NO_OPT __attribute__((__optimize__("O0")))
  82 #define EXTERNALLY_VISIBLE __attribute__((__externally_visible__))
  83 #endif
  84
  85 #if defined(__GNUC__)
  86 # define HHVM_ATTRIBUTE_WEAK __attribute__((__weak__))
  87 #elif defined(__clang__)
  88 # define HHVM_ATTRIBUTE_WEAK __attribute__((__weak_import__))
  89 #else
  90 # define HHVM_ATTRIBUTE_WEAK
  91 #endif
  92
  93 #ifndef NDEBUG
  94 # define DEBUG_ONLY /* nop */
  95 #else
  96 # define DEBUG_ONLY UNUSED
  97 #endif
  98
  99 #ifndef NDEBUG
 100 #define DEBUG_NOEXCEPT
 101 #else
 102 #define DEBUG_NOEXCEPT noexcept
 103 #endif
 104
 105
 106 /*
 107  * AARCH64 needs to create a walkable stack frame for
 108  * getFrameRegs() when a FixupEntry isIndirect()
 109  */
 110 #ifdef __aarch64__
 111 #define AARCH64_WALKABLE_FRAME() asm("" ::: "memory");
 112 #else
 113 #define AARCH64_WALKABLE_FRAME()
 114 #endif
 115
 116
 117 /*
 118  * We need to keep some unreferenced functions from being removed by
 119  * the linker. There is no compile time mechanism for doing this, but
 120  * by putting them in the same section as some other, referenced function
 121  * in the same file, we can keep them around.
 122  *
 123  * So this macro should be used to mark at least one function that is
 124  * referenced, and other functions that are not referenced in the same
 125  * file.
 126  *
 127  * Note: this may not work properly with LTO. We'll revisit when/if we
 128  * move to it.
 129  */
 130 # define KEEP_SECTION \
 131     __attribute__((__section__(".text.keep")))
 132
 133 //////////////////////////////////////////////////////////////////////
 134 // DECLARE_FRAME_POINTER
 135
 136 #if defined(__x86_64__)
 137
 138 # define DECLARE_FRAME_POINTER(fp) \
 139   auto const fp = (ActRec*) __builtin_frame_address(0)
 140 # define FRAME_POINTER_IS_ACCURATE
 141
 142 #elif defined(_M_X64)
 143
 144 // TODO: FIXME! Without this implemented properly, the JIT
 145 // will fail "pretty spectacularly".
 146 # define DECLARE_FRAME_POINTER(fp) \
 147   always_assert(false);            \
 148   ActRec* fp = nullptr;
 149
 150 #elif defined(__AARCH64EL__)
 151
 152 # if defined(__clang__)
 153 # define DECLARE_FRAME_POINTER(fp) ActRec* fp = (ActRec*) \
 154   __builtin_frame_address(0)
 155 #else
 156 # define DECLARE_FRAME_POINTER(fp) ActRec* fp asm("x29")
 157 #endif
 158
 159 #else
 160
 161 # error What are the stack and frame pointers called on your architecture?
 162
 163 #endif
 164
 165 //////////////////////////////////////////////////////////////////////
 166 // CALLEE_SAVED_BARRIER
 167
 168 #ifdef __AARCH64EL__
 169   #define CALLEE_SAVED_BARRIER()\
 170     asm volatile("" : : : "x19", "x20", "x21", "x22", "x23", "x24", "x25",\
 171                  "x26", "x27", "x28", \
 172                  "d8", "d9", "d10", "d11", "d12", "d13", "d14", "d15")
 173 #else
 174   #define CALLEE_SAVED_BARRIER()\
 175     asm volatile("" : : : "rbx", "r12", "r13", "r14", "r15");
 176 #endif
 177
 178 //////////////////////////////////////////////////////////////////////
 179
 180 // We reserve the exit status 127 to signal a failure. 127 is a valid
 181 // exit code on all reasonable architectures: POSIX requires at least
 182 // 8 unsigned bits and Windows 32 signed bits.
 183 #define HPHP_EXIT_FAILURE 127
 184
 185 // When HHVM server fails to shutdown within a timeout, we forcefully
 186 //exit the process with this exit code, similar to an unclean exit
 187 // upon SIGTERM (signal 15).
 188 #define HPHP_SHUTDOWN_TIMEOUT (128 + 15)
 189
 190 //////////////////////////////////////////////////////////////////////
 191
 192 #ifdef HHVM_FACEBOOK
 193 #define USE_FOLLY_SYMBOLIZER 1
 194 // Linking in libbfd is a gigantic PITA, but if folly symbolizer doesn't
 195 // work on your platform, you'll need to figure it out.
 196 #define HAVE_LIBBFD 1
 197 #endif
 198
 199 #ifndef PACKAGE
 200 // The value doesn't matter, but it must be defined before you include
 201 // bfd.h
 202 #define PACKAGE "hhvm"
 203 #endif
 204
 205 //////////////////////////////////////////////////////////////////////
 206
 207 #define ASM_LOCAL_LABEL(x) ".L" x