ppapi/api/pp_macros.idl

   1 /* Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2  * Use of this source code is governed by a BSD-style license that can be
   3  * found in the LICENSE file.
   4  */
   5
   6 /**
   7  * Defines the common macros such as assert, inline, ...
   8  */
   9
  10 #inline c
  11
  12 /*
  13  * @addtogroup PP
  14  * @{
  15  */
  16
  17 /* Use PP_INLINE to tell the compiler to inline functions.  The main purpose of
  18  * inline functions in ppapi is to allow us to define convenience functions in
  19  * the ppapi header files, without requiring clients or implementers to link a
  20  * PPAPI C library.  The "inline" keyword is not supported by pre-C99 C
  21  * compilers (such as MS Visual Studio 2008 and older versions of GCC).  MSVS
  22  * supports __forceinline and GCC supports __inline__.  Use of the static
  23  * keyword ensures (in C) that the function is not compiled on its own, which
  24  * could cause multiple definition errors.
  25  *  http://msdn.microsoft.com/en-us/library/z8y1yy88.aspx
  26  *  http://gcc.gnu.org/onlinedocs/gcc/Inline.html
  27  */
  28 #if defined(__cplusplus)
  29 /* The inline keyword is part of C++ and guarantees we won't get multiple
  30  * definition errors.
  31  */
  32 # define PP_INLINE inline
  33 #else
  34 # if defined(_MSC_VER)
  35 #  define PP_INLINE static __forceinline
  36 # else
  37 #  define PP_INLINE static __inline__
  38 # endif
  39 #endif
  40
  41 /* This is a compile-time assertion useful for ensuring that a given type is
  42    a given number of bytes wide.  The size of the array is designed to be 1
  43    (which should always be valid) if the enum's size is SIZE, and otherwise the
  44    size of the array will be -1 (which all/most compilers should flag as an
  45    error).  This is wrapped inside a struct, because if it is a simple global
  46    we get multiple definition errors at link time.
  47
  48    NAME is the name of the type without any spaces or the struct or enum
  49    keywords.
  50
  51    CTYPENAME is the typename required by C.  I.e., for a struct or enum, the
  52    appropriate keyword must be included.
  53
  54    SIZE is the expected size in bytes.
  55  */
  56 #define PP_COMPILE_ASSERT_SIZE_IN_BYTES_IMPL(NAME, CTYPENAME, SIZE) \
  57 struct PP_Dummy_Struct_For_##NAME { \
  58 char _COMPILE_ASSERT_FAILED_The_type_named_ \
  59 ## NAME ## _is_not_ ## SIZE ## \
  60 _bytes_wide[(sizeof(CTYPENAME) == SIZE) ? 1 : -1]; }
  61
  62 /* PP_COMPILE_ASSERT_SIZE_IN_BYTES is for typenames that contain no spaces.
  63    E.g.:
  64    PP_COMPILE_ASSERT_SIZE_IN_BYTES(int, 4);
  65    typedef struct { int a; } Foo;
  66    PP_COMPILE_ASSERT_SIZE_IN_BYTES(Foo, 4);
  67  */
  68 #define PP_COMPILE_ASSERT_SIZE_IN_BYTES(NAME, SIZE) \
  69 PP_COMPILE_ASSERT_SIZE_IN_BYTES_IMPL(NAME, NAME, SIZE)
  70
  71 /* PP_COMPILE_ASSERT_STRUCT_SIZE_IN_BYTES is for typenames that contain 'struct'
  72    in C.  That is, struct names that are not typedefs.
  73    E.g.:
  74    struct Foo { int a; };
  75    PP_COMPILE_ASSERT_STRUCT_SIZE_IN_BYTES(Foo, 4);
  76  */
  77 #define PP_COMPILE_ASSERT_STRUCT_SIZE_IN_BYTES(NAME, SIZE) \
  78 PP_COMPILE_ASSERT_SIZE_IN_BYTES_IMPL(NAME, struct NAME, SIZE)
  79
  80 /* PP_COMPILE_ASSERT_ENUM_SIZE_IN_BYTES is for typenames that contain 'enum'
  81    in C.  That is, enum names that are not typedefs.
  82    E.g.:
  83    enum Bar { A = 0, B = 1 };
  84    PP_COMPILE_ASSERT_ENUM_SIZE_IN_BYTES(Foo, 4);
  85  */
  86 #define PP_COMPILE_ASSERT_ENUM_SIZE_IN_BYTES(NAME, SIZE) \
  87 PP_COMPILE_ASSERT_SIZE_IN_BYTES_IMPL(NAME, enum NAME, SIZE)
  88
  89 /**
  90  * @}
  91  * End of addtogroup PP
  92  */
  93
  94 #endinl