js/src/jstypes.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
   2  * vim: set ts=8 sts=4 et sw=4 tw=99:
   3  * This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 /*
   8 ** File:                jstypes.h
   9 ** Description: Definitions of NSPR's basic types
  10 **
  11 ** Prototypes and macros used to make up for deficiencies in ANSI environments
  12 ** that we have found.
  13 **
  14 ** Since we do not wrap <stdlib.h> and all the other standard headers, authors
  15 ** of portable code will not know in general that they need these definitions.
  16 ** Instead of requiring these authors to find the dependent uses in their code
  17 ** and take the following steps only in those C files, we take steps once here
  18 ** for all C files.
  19 **/
  20
  21 #ifndef jstypes_h
  22 #define jstypes_h
  23
  24 #include "mozilla/Attributes.h"
  25 #include "mozilla/Casting.h"
  26 #include "mozilla/Types.h"
  27
  28 // jstypes.h is (or should be!) included by every file in SpiderMonkey.
  29 // js-config.h also should be included by every file. So include it here.
  30 // XXX: including it in js/RequiredDefines.h should be a better option, since
  31 // that is by definition the header file that should be included in all
  32 // SpiderMonkey code.  However, Gecko doesn't do this!  See bug 909576.
  33 #include "js-config.h"
  34
  35 /*
  36  * The linkage of JS API functions differs depending on whether the file is
  37  * used within the JS library or not. Any source file within the JS
  38  * interpreter should define EXPORT_JS_API whereas any client of the library
  39  * should not. STATIC_JS_API is used to build JS as a static library.
  40  */
  41 #if defined(STATIC_JS_API)
  42 #  define JS_PUBLIC_API(t)   t
  43 #  define JS_PUBLIC_DATA(t)  t
  44 #  define JS_FRIEND_API(t)   t
  45 #  define JS_FRIEND_DATA(t)  t
  46 #elif defined(EXPORT_JS_API) || defined(STATIC_EXPORTABLE_JS_API)
  47 #  define JS_PUBLIC_API(t)   MOZ_EXPORT t
  48 #  define JS_PUBLIC_DATA(t)  MOZ_EXPORT t
  49 #  define JS_FRIEND_API(t)    MOZ_EXPORT t
  50 #  define JS_FRIEND_DATA(t)   MOZ_EXPORT t
  51 #else
  52 #  define JS_PUBLIC_API(t)   MOZ_IMPORT_API t
  53 #  define JS_PUBLIC_DATA(t)  MOZ_IMPORT_DATA t
  54 #  define JS_FRIEND_API(t)   MOZ_IMPORT_API t
  55 #  define JS_FRIEND_DATA(t)  MOZ_IMPORT_DATA t
  56 #endif
  57
  58 #if defined(_MSC_VER) && defined(_M_IX86)
  59 #define JS_FASTCALL __fastcall
  60 #elif defined(__GNUC__) && defined(__i386__)
  61 #define JS_FASTCALL __attribute__((fastcall))
  62 #else
  63 #define JS_FASTCALL
  64 #define JS_NO_FASTCALL
  65 #endif
  66
  67 // gcc is buggy and warns on our attempts to JS_PUBLIC_API our
  68 // forward-declarations or explicit template instantiations.  See
  69 // <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50044>.  Add a way to detect
  70 // that so we can locally disable that warning.
  71 //
  72 // This version-check is written such that the version-number mentioned below
  73 // must be bumped every time a new gcc that *doesn't* fix this bug is released.
  74 // (The gcc release that *fixes* this bug will trigger no warning, and we'll
  75 // naturally stop bumping this number.)  If you ever trigger this warning with
  76 // the latest stable gcc, you have rs=jwalden to bump it to the next gcc minor
  77 // version, e.g. (8, 1, 0) to (8, 2, 0).
  78 #if MOZ_IS_GCC
  79 #  if !MOZ_GCC_VERSION_AT_LEAST(8, 1, 0)
  80 #    define JS_BROKEN_GCC_ATTRIBUTE_WARNING
  81 #  endif
  82 #endif
  83
  84 /***********************************************************************
  85 ** MACROS:      JS_BEGIN_MACRO
  86 **              JS_END_MACRO
  87 ** DESCRIPTION:
  88 **      Macro body brackets so that macros with compound statement definitions
  89 **      behave syntactically more like functions when called.
  90 ***********************************************************************/
  91 #define JS_BEGIN_MACRO  do {
  92 #define JS_END_MACRO   } while (0)
  93
  94 /***********************************************************************
  95 ** MACROS:      JS_BIT
  96 **              JS_BITMASK
  97 ** DESCRIPTION:
  98 ** Bit masking macros.  XXX n must be <= 31 to be portable
  99 ***********************************************************************/
 100 #define JS_BIT(n)       ((uint32_t)1 << (n))
 101 #define JS_BITMASK(n)   (JS_BIT(n) - 1)
 102
 103 /***********************************************************************
 104 ** MACROS:      JS_HOWMANY
 105 **              JS_ROUNDUP
 106 ** DESCRIPTION:
 107 **      Commonly used macros for operations on compatible types.
 108 ***********************************************************************/
 109 #define JS_HOWMANY(x,y) (((x)+(y)-1)/(y))
 110 #define JS_ROUNDUP(x,y) (JS_HOWMANY(x,y)*(y))
 111
 112 #if defined(JS_64BIT)
 113 # define JS_BITS_PER_WORD 64
 114 #else
 115 # define JS_BITS_PER_WORD 32
 116 #endif
 117
 118 /***********************************************************************
 119 ** MACROS:      JS_FUNC_TO_DATA_PTR
 120 **              JS_DATA_TO_FUNC_PTR
 121 ** DESCRIPTION:
 122 **      Macros to convert between function and data pointers of the same
 123 **      size. Use them like this:
 124 **
 125 **      JSGetterOp nativeGetter;
 126 **      JSObject* scriptedGetter;
 127 **      ...
 128 **      scriptedGetter = JS_FUNC_TO_DATA_PTR(JSObject*, nativeGetter);
 129 **      ...
 130 **      nativeGetter = JS_DATA_TO_FUNC_PTR(JSGetterOp, scriptedGetter);
 131 **
 132 ***********************************************************************/
 133
 134 #define JS_FUNC_TO_DATA_PTR(type, fun)  (mozilla::BitwiseCast<type>(fun))
 135 #define JS_DATA_TO_FUNC_PTR(type, ptr)  (mozilla::BitwiseCast<type>(ptr))
 136
 137 #endif /* jstypes_h */