1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
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 /* Various compiler checks. */
8 
9 #ifndef mozilla_Compiler_h
10 #define mozilla_Compiler_h
11 
12 #define MOZ_IS_GCC 0
13 #define MOZ_IS_MSVC 0
14 
15 #if !defined(__clang__) && defined(__GNUC__)
16 
17 #undef MOZ_IS_GCC
18 #define MOZ_IS_GCC 1
19 /*
20  * These macros should simplify gcc version checking. For example, to check
21  * for gcc 4.7.1 or later, check `#if MOZ_GCC_VERSION_AT_LEAST(4, 7, 1)`.
22  */
23 #define MOZ_GCC_VERSION_AT_LEAST(major, minor, patchlevel)            \
24   ((__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) >= \
25    ((major)*10000 + (minor)*100 + (patchlevel)))
26 #define MOZ_GCC_VERSION_AT_MOST(major, minor, patchlevel)             \
27   ((__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) <= \
28    ((major)*10000 + (minor)*100 + (patchlevel)))
29 #if !MOZ_GCC_VERSION_AT_LEAST(4, 9, 0)
30 #error "mfbt (and Gecko) require at least gcc 4.9 to build."
31 #endif
32 
33 #elif defined(_MSC_VER)
34 
35 #undef MOZ_IS_MSVC
36 #define MOZ_IS_MSVC 1
37 
38 #endif
39 
40 /*
41  * The situation with standard libraries is a lot worse than with compilers,
42  * particularly as clang and gcc could end up using one of three or so standard
43  * libraries, and they may not be up-to-snuff with newer C++11 versions. To
44  * detect the library, we're going to include cstddef (which is a small header
45  * which will be transitively included by everybody else at some point) to grab
46  * the version macros and deduce macros from there.
47  */
48 #ifdef __cplusplus
49 #include <cstddef>
50 #ifdef _STLPORT_MAJOR
51 #define MOZ_USING_STLPORT 1
52 #define MOZ_STLPORT_VERSION_AT_LEAST(major, minor, patch) \
53   (_STLPORT_VERSION >= ((major) << 8 | (minor) << 4 | (patch)))
54 #elif defined(_LIBCPP_VERSION)
55 /*
56  * libc++, unfortunately, doesn't appear to have useful versioning macros.
57  * Hopefully, the recommendations of N3694 with respect to standard libraries
58  * will get applied instead and we won't need to worry about version numbers
59  * here.
60  */
61 #define MOZ_USING_LIBCXX 1
62 #elif defined(__GLIBCXX__)
63 #define MOZ_USING_LIBSTDCXX 1
64 /*
65  * libstdc++ is also annoying and doesn't give us useful versioning macros
66  * for the library. If we're using gcc, then assume that libstdc++ matches
67  * the compiler version. If we're using clang, we're going to have to fake
68  * major/minor combinations by looking for newly-defined config macros.
69  */
70 #if MOZ_IS_GCC
71 #define MOZ_LIBSTDCXX_VERSION_AT_LEAST(major, minor, patch) \
72   MOZ_GCC_VERSION_AT_LEAST(major, minor, patch)
73 #elif defined(_GLIBCXX_THROW_OR_ABORT)
74 #define MOZ_LIBSTDCXX_VERSION_AT_LEAST(major, minor, patch) \
75   ((major) < 4 || ((major) == 4 && (minor) <= 8))
76 #elif defined(_GLIBCXX_NOEXCEPT)
77 #define MOZ_LIBSTDCXX_VERSION_AT_LEAST(major, minor, patch) \
78   ((major) < 4 || ((major) == 4 && (minor) <= 7))
79 #elif defined(_GLIBCXX_USE_DEPRECATED)
80 #define MOZ_LIBSTDCXX_VERSION_AT_LEAST(major, minor, patch) \
81   ((major) < 4 || ((major) == 4 && (minor) <= 6))
82 #elif defined(_GLIBCXX_PSEUDO_VISIBILITY)
83 #define MOZ_LIBSTDCXX_VERSION_AT_LEAST(major, minor, patch) \
84   ((major) < 4 || ((major) == 4 && (minor) <= 5))
85 #elif defined(_GLIBCXX_BEGIN_EXTERN_C)
86 #define MOZ_LIBSTDCXX_VERSION_AT_LEAST(major, minor, patch) \
87   ((major) < 4 || ((major) == 4 && (minor) <= 4))
88 #elif defined(_GLIBCXX_VISIBILITY_ATTR)
89 #define MOZ_LIBSTDCXX_VERSION_AT_LEAST(major, minor, patch) \
90   ((major) < 4 || ((major) == 4 && (minor) <= 3))
91 #elif defined(_GLIBCXX_VISIBILITY)
92 #define MOZ_LIBSTDCXX_VERSION_AT_LEAST(major, minor, patch) \
93   ((major) < 4 || ((major) == 4 && (minor) <= 2))
94 #else
95 #error "Your version of libstdc++ is unknown to us and is likely too old."
96 #endif
97 #endif
98 
99 // Flesh out the defines for everyone else
100 #ifndef MOZ_USING_STLPORT
101 #define MOZ_USING_STLPORT 0
102 #define MOZ_STLPORT_VERSION_AT_LEAST(major, minor, patch) 0
103 #endif
104 #ifndef MOZ_USING_LIBCXX
105 #define MOZ_USING_LIBCXX 0
106 #endif
107 #ifndef MOZ_USING_LIBSTDCXX
108 #define MOZ_USING_LIBSTDCXX 0
109 #define MOZ_LIBSTDCXX_VERSION_AT_LEAST(major, minor, patch) 0
110 #endif
111 #endif /* __cplusplus */
112 
113 #endif /* mozilla_Compiler_h */
114