xref: /freebsd/contrib/kyua/m4/compiler-features.m4 (revision 59c8e88e72633afbc47a4ace0d2170d00d51f7dc)
1dnl Copyright 2010 The Kyua Authors.
2dnl All rights reserved.
3dnl
4dnl Redistribution and use in source and binary forms, with or without
5dnl modification, are permitted provided that the following conditions are
6dnl met:
7dnl
8dnl * Redistributions of source code must retain the above copyright
9dnl   notice, this list of conditions and the following disclaimer.
10dnl * Redistributions in binary form must reproduce the above copyright
11dnl   notice, this list of conditions and the following disclaimer in the
12dnl   documentation and/or other materials provided with the distribution.
13dnl * Neither the name of Google Inc. nor the names of its contributors
14dnl   may be used to endorse or promote products derived from this software
15dnl   without specific prior written permission.
16dnl
17dnl THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18dnl "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19dnl LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20dnl A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21dnl OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22dnl SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23dnl LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24dnl DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25dnl THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26dnl (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27dnl OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28
29dnl
30dnl KYUA_ATTRIBUTE_NORETURN
31dnl
32dnl Checks if the current compiler has a way to mark functions that do not
33dnl return and defines ATTRIBUTE_NORETURN to the appropriate string.
34dnl
35AC_DEFUN([KYUA_ATTRIBUTE_NORETURN], [
36    dnl This check is overly simple and should be fixed.  For example,
37    dnl Sun's cc does support the noreturn attribute but CC (the C++
38    dnl compiler) does not.  And in that case, CC just raises a warning
39    dnl during compilation, not an error.
40    AC_CACHE_CHECK(
41        [whether __attribute__((noreturn)) is supported],
42        [kyua_cv_attribute_noreturn], [
43        AC_RUN_IFELSE([AC_LANG_PROGRAM([], [
44#if ((__GNUC__ == 2 && __GNUC_MINOR__ >= 5) || __GNUC__ > 2)
45    return 0;
46#else
47    return 1;
48#endif
49            ])],
50            [kyua_cv_attribute_noreturn=yes],
51            [kyua_cv_attribute_noreturn=no])
52    ])
53    if test "${kyua_cv_attribute_noreturn}" = yes; then
54        attribute_value="__attribute__((noreturn))"
55    else
56        attribute_value=""
57    fi
58    AC_SUBST([ATTRIBUTE_NORETURN], [${attribute_value}])
59])
60
61
62dnl
63dnl KYUA_ATTRIBUTE_PURE
64dnl
65dnl Checks if the current compiler has a way to mark functions as pure.
66dnl
67AC_DEFUN([KYUA_ATTRIBUTE_PURE], [
68    AC_CACHE_CHECK(
69        [whether __attribute__((__pure__)) is supported],
70        [kyua_cv_attribute_pure], [
71        AC_COMPILE_IFELSE(
72            [AC_LANG_PROGRAM([
73static int function(int, int) __attribute__((__pure__));
74
75static int
76function(int a, int b)
77{
78    return a + b;
79}], [
80    return function(3, 4);
81])],
82            [kyua_cv_attribute_pure=yes],
83            [kyua_cv_attribute_pure=no])
84    ])
85    if test "${kyua_cv_attribute_pure}" = yes; then
86        attribute_value="__attribute__((__pure__))"
87    else
88        attribute_value=""
89    fi
90    AC_SUBST([ATTRIBUTE_PURE], [${attribute_value}])
91])
92
93
94dnl
95dnl KYUA_ATTRIBUTE_UNUSED
96dnl
97dnl Checks if the current compiler has a way to mark parameters as unused
98dnl so that the -Wunused-parameter warning can be avoided.
99dnl
100AC_DEFUN([KYUA_ATTRIBUTE_UNUSED], [
101    AC_CACHE_CHECK(
102        [whether __attribute__((__unused__)) is supported],
103        [kyua_cv_attribute_unused], [
104        AC_COMPILE_IFELSE(
105            [AC_LANG_PROGRAM([
106static void
107function(int a __attribute__((__unused__)))
108{
109}], [
110    function(3);
111    return 0;
112])],
113            [kyua_cv_attribute_unused=yes],
114            [kyua_cv_attribute_unused=no])
115    ])
116    if test "${kyua_cv_attribute_unused}" = yes; then
117        attribute_value="__attribute__((__unused__))"
118    else
119        attribute_value=""
120    fi
121    AC_SUBST([ATTRIBUTE_UNUSED], [${attribute_value}])
122])
123