1 | #ifndef MY_COMPILER_INCLUDED |
2 | #define MY_COMPILER_INCLUDED |
3 | |
4 | /* Copyright (c) 2010, 2011, Oracle and/or its affiliates. All rights reserved. |
5 | |
6 | This program is free software; you can redistribute it and/or modify |
7 | it under the terms of the GNU General Public License as published by |
8 | the Free Software Foundation; version 2 of the License. |
9 | |
10 | This program is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
13 | GNU General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU General Public License |
16 | along with this program; if not, write to the Free Software |
17 | Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ |
18 | |
19 | /** |
20 | Header for compiler-dependent features. |
21 | |
22 | Intended to contain a set of reusable wrappers for preprocessor |
23 | macros, attributes, pragmas, and any other features that are |
24 | specific to a target compiler. |
25 | */ |
26 | |
27 | /** |
28 | Compiler-dependent internal convenience macros. |
29 | */ |
30 | |
31 | /* GNU C/C++ */ |
32 | #if defined __GNUC__ |
33 | /* Convenience macro to test the minimum required GCC version. */ |
34 | # define MY_GNUC_PREREQ(maj, min) \ |
35 | ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min)) |
36 | /* Any after 2.95... */ |
37 | # define MY_ALIGN_EXT |
38 | /* Comunicate to the compiler the unreachability of the code. */ |
39 | # if MY_GNUC_PREREQ(4,5) |
40 | # define MY_ASSERT_UNREACHABLE() __builtin_unreachable() |
41 | # endif |
42 | |
43 | /* Microsoft Visual C++ */ |
44 | #elif defined _MSC_VER |
45 | # define MY_ALIGNOF(type) __alignof(type) |
46 | # define MY_ALIGNED(n) __declspec(align(n)) |
47 | |
48 | /* Oracle Solaris Studio */ |
49 | #elif defined(__SUNPRO_C) || defined(__SUNPRO_CC) |
50 | # if __SUNPRO_C >= 0x590 |
51 | # define MY_ALIGN_EXT |
52 | # endif |
53 | |
54 | /* IBM XL C/C++ */ |
55 | #elif defined __xlC__ |
56 | # if __xlC__ >= 0x0600 |
57 | # define MY_ALIGN_EXT |
58 | # endif |
59 | |
60 | /* HP aCC */ |
61 | #elif defined(__HP_aCC) || defined(__HP_cc) |
62 | # if (__HP_aCC >= 60000) || (__HP_cc >= 60000) |
63 | # define MY_ALIGN_EXT |
64 | # endif |
65 | #endif |
66 | |
67 | #ifdef MY_ALIGN_EXT |
68 | /** Specifies the minimum alignment of a type. */ |
69 | # define MY_ALIGNOF(type) __alignof__(type) |
70 | /** Determine the alignment requirement of a type. */ |
71 | # define MY_ALIGNED(n) __attribute__((__aligned__((n)))) |
72 | #endif |
73 | |
74 | /** |
75 | Generic (compiler-independent) features. |
76 | */ |
77 | |
78 | #ifndef MY_GNUC_PREREQ |
79 | # define MY_GNUC_PREREQ(maj, min) (0) |
80 | #endif |
81 | |
82 | #ifndef MY_ALIGNOF |
83 | # ifdef __cplusplus |
84 | template<typename type> struct my_alignof_helper { char m1; type m2; }; |
85 | /* Invalid for non-POD types, but most compilers give the right answer. */ |
86 | # define MY_ALIGNOF(type) offsetof(my_alignof_helper<type>, m2) |
87 | # else |
88 | # define MY_ALIGNOF(type) offsetof(struct { char m1; type m2; }, m2) |
89 | # endif |
90 | #endif |
91 | |
92 | #ifndef MY_ASSERT_UNREACHABLE |
93 | # define MY_ASSERT_UNREACHABLE() do { assert(0); } while (0) |
94 | #endif |
95 | |
96 | /** |
97 | C++ Type Traits |
98 | */ |
99 | |
100 | #ifdef __cplusplus |
101 | |
102 | /** |
103 | Opaque storage with a particular alignment. |
104 | */ |
105 | # if defined(MY_ALIGNED) |
106 | /* Partial specialization used due to MSVC++. */ |
107 | template<size_t alignment> struct my_alignment_imp; |
108 | template<> struct MY_ALIGNED(1) my_alignment_imp<1> {}; |
109 | template<> struct MY_ALIGNED(2) my_alignment_imp<2> {}; |
110 | template<> struct MY_ALIGNED(4) my_alignment_imp<4> {}; |
111 | template<> struct MY_ALIGNED(8) my_alignment_imp<8> {}; |
112 | template<> struct MY_ALIGNED(16) my_alignment_imp<16> {}; |
113 | /* ... expand as necessary. */ |
114 | # else |
115 | template<size_t alignment> |
116 | struct my_alignment_imp { double m1; }; |
117 | # endif |
118 | |
119 | /** |
120 | A POD type with a given size and alignment. |
121 | |
122 | @remark If the compiler does not support a alignment attribute |
123 | (MY_ALIGN macro), the default alignment of a double is |
124 | used instead. |
125 | |
126 | @tparam size The minimum size. |
127 | @tparam alignment The desired alignment: 1, 2, 4, 8 or 16. |
128 | */ |
129 | template <size_t size, size_t alignment> |
130 | struct my_aligned_storage |
131 | { |
132 | union |
133 | { |
134 | char data[size]; |
135 | my_alignment_imp<alignment> align; |
136 | }; |
137 | }; |
138 | |
139 | #endif /* __cplusplus */ |
140 | |
141 | # ifndef MY_ALIGNED |
142 | /* |
143 | Make sure MY_ALIGNED can be used also on platforms where we don't |
144 | have a way of aligning data structures. |
145 | */ |
146 | #define MY_ALIGNED(size) |
147 | #endif |
148 | |
149 | #ifdef __GNUC__ |
150 | # define ATTRIBUTE_NORETURN __attribute__((noreturn)) |
151 | # if MY_GNUC_PREREQ(4,3) |
152 | /** Starting with GCC 4.3, the "cold" attribute is used to inform the |
153 | compiler that a function is unlikely executed. The function is |
154 | optimized for size rather than speed and on many targets it is placed |
155 | into special subsection of the text section so all cold functions |
156 | appears close together improving code locality of non-cold parts of |
157 | program. The paths leading to call of cold functions within code are |
158 | marked as unlikely by the branch prediction mechanism. optimize a |
159 | rarely invoked function for size instead for speed. */ |
160 | # define ATTRIBUTE_COLD __attribute__((cold)) |
161 | # endif |
162 | #elif defined _MSC_VER |
163 | # define ATTRIBUTE_NORETURN __declspec(noreturn) |
164 | #else |
165 | # define ATTRIBUTE_NORETURN /* empty */ |
166 | #endif |
167 | |
168 | #ifndef ATTRIBUTE_COLD |
169 | # define ATTRIBUTE_COLD /* empty */ |
170 | #endif |
171 | |
172 | #include <my_attribute.h> |
173 | |
174 | #endif /* MY_COMPILER_INCLUDED */ |
175 | |