Merge from gnulib.
[bpt/emacs.git] / m4 / gnulib-common.m4
1 # gnulib-common.m4 serial 25
2 dnl Copyright (C) 2007-2011 Free Software Foundation, Inc.
3 dnl This file is free software; the Free Software Foundation
4 dnl gives unlimited permission to copy and/or distribute it,
5 dnl with or without modifications, as long as this notice is preserved.
6
7 # gl_COMMON
8 # is expanded unconditionally through gnulib-tool magic.
9 AC_DEFUN([gl_COMMON], [
10 dnl Use AC_REQUIRE here, so that the code is expanded once only.
11 AC_REQUIRE([gl_00GNULIB])
12 AC_REQUIRE([gl_COMMON_BODY])
13 ])
14 AC_DEFUN([gl_COMMON_BODY], [
15 AH_VERBATIM([isoc99_inline],
16 [/* Work around a bug in Apple GCC 4.0.1 build 5465: In C99 mode, it supports
17 the ISO C 99 semantics of 'extern inline' (unlike the GNU C semantics of
18 earlier versions), but does not display it by setting __GNUC_STDC_INLINE__.
19 __APPLE__ && __MACH__ test for MacOS X.
20 __APPLE_CC__ tests for the Apple compiler and its version.
21 __STDC_VERSION__ tests for the C99 mode. */
22 #if defined __APPLE__ && defined __MACH__ && __APPLE_CC__ >= 5465 && !defined __cplusplus && __STDC_VERSION__ >= 199901L && !defined __GNUC_STDC_INLINE__
23 # define __GNUC_STDC_INLINE__ 1
24 #endif])
25 AH_VERBATIM([unused_parameter],
26 [/* Define as a marker that can be attached to declarations that might not
27 be used. This helps to reduce warnings, such as from
28 GCC -Wunused-parameter. */
29 #if __GNUC__ >= 3 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 7)
30 # define _GL_UNUSED __attribute__ ((__unused__))
31 #else
32 # define _GL_UNUSED
33 #endif
34 /* The name _UNUSED_PARAMETER_ is an earlier spelling, although the name
35 is a misnomer outside of parameter lists. */
36 #define _UNUSED_PARAMETER_ _GL_UNUSED
37
38 /* The __pure__ attribute was added in gcc 2.96. */
39 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96)
40 # define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__))
41 #else
42 # define _GL_ATTRIBUTE_PURE /* empty */
43 #endif
44
45 /* The __const__ attribute was added in gcc 2.95. */
46 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 95)
47 # define _GL_ATTRIBUTE_CONST __attribute__ ((__const__))
48 #else
49 # define _GL_ATTRIBUTE_CONST /* empty */
50 #endif
51 ])
52 dnl Preparation for running test programs:
53 dnl Tell glibc to write diagnostics from -D_FORTIFY_SOURCE=2 to stderr, not
54 dnl to /dev/tty, so they can be redirected to log files. Such diagnostics
55 dnl arise e.g., in the macros gl_PRINTF_DIRECTIVE_N, gl_SNPRINTF_DIRECTIVE_N.
56 LIBC_FATAL_STDERR_=1
57 export LIBC_FATAL_STDERR_
58 ])
59
60 # gl_MODULE_INDICATOR_CONDITION
61 # expands to a C preprocessor expression that evaluates to 1 or 0, depending
62 # whether a gnulib module that has been requested shall be considered present
63 # or not.
64 AC_DEFUN([gl_MODULE_INDICATOR_CONDITION], [1])
65
66 # gl_MODULE_INDICATOR_SET_VARIABLE([modulename])
67 # sets the shell variable that indicates the presence of the given module to
68 # a C preprocessor expression that will evaluate to 1.
69 AC_DEFUN([gl_MODULE_INDICATOR_SET_VARIABLE],
70 [
71 GNULIB_[]m4_translit([[$1]],
72 [abcdefghijklmnopqrstuvwxyz./-],
73 [ABCDEFGHIJKLMNOPQRSTUVWXYZ___])=gl_MODULE_INDICATOR_CONDITION
74 ])
75
76 # gl_MODULE_INDICATOR([modulename])
77 # defines a C macro indicating the presence of the given module
78 # in a location where it can be used.
79 # | Value | Value |
80 # | in lib/ | in tests/ |
81 # --------------------------------------------+---------+-----------+
82 # Module present among main modules: | 1 | 1 |
83 # --------------------------------------------+---------+-----------+
84 # Module present among tests-related modules: | 0 | 1 |
85 # --------------------------------------------+---------+-----------+
86 # Module not present at all: | 0 | 0 |
87 # --------------------------------------------+---------+-----------+
88 AC_DEFUN([gl_MODULE_INDICATOR],
89 [
90 AC_DEFINE_UNQUOTED([GNULIB_]m4_translit([[$1]],
91 [abcdefghijklmnopqrstuvwxyz./-],
92 [ABCDEFGHIJKLMNOPQRSTUVWXYZ___]),
93 [gl_MODULE_INDICATOR_CONDITION],
94 [Define to a C preprocessor expression that evaluates to 1 or 0,
95 depending whether the gnulib module $1 shall be considered present.])
96 ])
97
98 # gl_MODULE_INDICATOR_FOR_TESTS([modulename])
99 # defines a C macro indicating the presence of the given module
100 # in lib or tests. This is useful to determine whether the module
101 # should be tested.
102 # | Value | Value |
103 # | in lib/ | in tests/ |
104 # --------------------------------------------+---------+-----------+
105 # Module present among main modules: | 1 | 1 |
106 # --------------------------------------------+---------+-----------+
107 # Module present among tests-related modules: | 1 | 1 |
108 # --------------------------------------------+---------+-----------+
109 # Module not present at all: | 0 | 0 |
110 # --------------------------------------------+---------+-----------+
111 AC_DEFUN([gl_MODULE_INDICATOR_FOR_TESTS],
112 [
113 AC_DEFINE([GNULIB_TEST_]m4_translit([[$1]],
114 [abcdefghijklmnopqrstuvwxyz./-],
115 [ABCDEFGHIJKLMNOPQRSTUVWXYZ___]), [1],
116 [Define to 1 when the gnulib module $1 should be tested.])
117 ])
118
119 # gl_ASSERT_NO_GNULIB_POSIXCHECK
120 # asserts that there will never be a need to #define GNULIB_POSIXCHECK.
121 # and thereby enables an optimization of configure and config.h.
122 # Used by Emacs.
123 AC_DEFUN([gl_ASSERT_NO_GNULIB_POSIXCHECK],
124 [
125 dnl Override gl_WARN_ON_USE_PREPARE.
126 dnl But hide this definition from 'aclocal'.
127 AC_DEFUN([gl_W][ARN_ON_USE_PREPARE], [])
128 ])
129
130 # gl_ASSERT_NO_GNULIB_TESTS
131 # asserts that there will be no gnulib tests in the scope of the configure.ac
132 # and thereby enables an optimization of config.h.
133 # Used by Emacs.
134 AC_DEFUN([gl_ASSERT_NO_GNULIB_TESTS],
135 [
136 dnl Override gl_MODULE_INDICATOR_FOR_TESTS.
137 AC_DEFUN([gl_MODULE_INDICATOR_FOR_TESTS], [])
138 ])
139
140 # Test whether <features.h> exists.
141 # Set HAVE_FEATURES_H.
142 AC_DEFUN([gl_FEATURES_H],
143 [
144 AC_CHECK_HEADERS_ONCE([features.h])
145 if test $ac_cv_header_features_h = yes; then
146 HAVE_FEATURES_H=1
147 else
148 HAVE_FEATURES_H=0
149 fi
150 AC_SUBST([HAVE_FEATURES_H])
151 ])
152
153 # m4_foreach_w
154 # is a backport of autoconf-2.59c's m4_foreach_w.
155 # Remove this macro when we can assume autoconf >= 2.60.
156 m4_ifndef([m4_foreach_w],
157 [m4_define([m4_foreach_w],
158 [m4_foreach([$1], m4_split(m4_normalize([$2]), [ ]), [$3])])])
159
160 # AS_VAR_IF(VAR, VALUE, [IF-MATCH], [IF-NOT-MATCH])
161 # ----------------------------------------------------
162 # Backport of autoconf-2.63b's macro.
163 # Remove this macro when we can assume autoconf >= 2.64.
164 m4_ifndef([AS_VAR_IF],
165 [m4_define([AS_VAR_IF],
166 [AS_IF([test x"AS_VAR_GET([$1])" = x""$2], [$3], [$4])])])
167
168 # AC_PROG_MKDIR_P
169 # is a backport of autoconf-2.60's AC_PROG_MKDIR_P, with a fix
170 # for interoperability with automake-1.9.6 from autoconf-2.62.
171 # Remove this macro when we can assume autoconf >= 2.62 or
172 # autoconf >= 2.60 && automake >= 1.10.
173 m4_ifdef([AC_PROG_MKDIR_P], [
174 dnl For automake-1.9.6 && autoconf < 2.62: Ensure MKDIR_P is AC_SUBSTed.
175 m4_define([AC_PROG_MKDIR_P],
176 m4_defn([AC_PROG_MKDIR_P])[
177 AC_SUBST([MKDIR_P])])], [
178 dnl For autoconf < 2.60: Backport of AC_PROG_MKDIR_P.
179 AC_DEFUN_ONCE([AC_PROG_MKDIR_P],
180 [AC_REQUIRE([AM_PROG_MKDIR_P])dnl defined by automake
181 MKDIR_P='$(mkdir_p)'
182 AC_SUBST([MKDIR_P])])])
183
184 # AC_C_RESTRICT
185 # This definition overrides the AC_C_RESTRICT macro from autoconf 2.60..2.61,
186 # so that mixed use of GNU C and GNU C++ and mixed use of Sun C and Sun C++
187 # works.
188 # This definition can be removed once autoconf >= 2.62 can be assumed.
189 m4_if(m4_version_compare(m4_defn([m4_PACKAGE_VERSION]),[2.62]),[-1],[
190 AC_DEFUN([AC_C_RESTRICT],
191 [AC_CACHE_CHECK([for C/C++ restrict keyword], [ac_cv_c_restrict],
192 [ac_cv_c_restrict=no
193 # The order here caters to the fact that C++ does not require restrict.
194 for ac_kw in __restrict __restrict__ _Restrict restrict; do
195 AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
196 [[typedef int * int_ptr;
197 int foo (int_ptr $ac_kw ip) {
198 return ip[0];
199 }]],
200 [[int s[1];
201 int * $ac_kw t = s;
202 t[0] = 0;
203 return foo(t)]])],
204 [ac_cv_c_restrict=$ac_kw])
205 test "$ac_cv_c_restrict" != no && break
206 done
207 ])
208 AH_VERBATIM([restrict],
209 [/* Define to the equivalent of the C99 'restrict' keyword, or to
210 nothing if this is not supported. Do not define if restrict is
211 supported directly. */
212 #undef restrict
213 /* Work around a bug in Sun C++: it does not support _Restrict, even
214 though the corresponding Sun C compiler does, which causes
215 "#define restrict _Restrict" in the previous line. Perhaps some future
216 version of Sun C++ will work with _Restrict; if so, it'll probably
217 define __RESTRICT, just as Sun C does. */
218 #if defined __SUNPRO_CC && !defined __RESTRICT
219 # define _Restrict
220 #endif])
221 case $ac_cv_c_restrict in
222 restrict) ;;
223 no) AC_DEFINE([restrict], []) ;;
224 *) AC_DEFINE_UNQUOTED([restrict], [$ac_cv_c_restrict]) ;;
225 esac
226 ])
227 ])
228
229 # gl_BIGENDIAN
230 # is like AC_C_BIGENDIAN, except that it can be AC_REQUIREd.
231 # Note that AC_REQUIRE([AC_C_BIGENDIAN]) does not work reliably because some
232 # macros invoke AC_C_BIGENDIAN with arguments.
233 AC_DEFUN([gl_BIGENDIAN],
234 [
235 AC_C_BIGENDIAN
236 ])
237
238 # gl_CACHE_VAL_SILENT(cache-id, command-to-set-it)
239 # is like AC_CACHE_VAL(cache-id, command-to-set-it), except that it does not
240 # output a spurious "(cached)" mark in the midst of other configure output.
241 # This macro should be used instead of AC_CACHE_VAL when it is not surrounded
242 # by an AC_MSG_CHECKING/AC_MSG_RESULT pair.
243 AC_DEFUN([gl_CACHE_VAL_SILENT],
244 [
245 saved_as_echo_n="$as_echo_n"
246 as_echo_n=':'
247 AC_CACHE_VAL([$1], [$2])
248 as_echo_n="$saved_as_echo_n"
249 ])