Mercurial > octave

comparison m4/prog_c.m4 @ 21304:0cf6c08cb252

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
configure.ac: check support for C11 and C++11 (patch #8906) * configure.ac: two new checks for support of C++11 and C11 versions of the standard and to add required flags to CXX and CC. These need to be done before AC_PROG_CPP and AC_PROG_CXXPP since the later will make use of the defined CXX and CC. * m4/prog_c.m4, m4/prog_cxx.m4: added files for OCTAVE_PROG_CC_C11 and OCTAVE_PROG_CXX_CXX11 which are copied from autoconf source tree implementations of _AC_PROG_CC_C11 and _AC_PROG_CXX_CXX11.
author Carnë Draug <carandraug@octave.org>
date Thu, 18 Feb 2016 16:20:49 +0000
parents
children 822dc5a202c9
comparison
equal deleted inserted replaced
21303:325e04c63f8c 21304:0cf6c08cb252
1 # Copyright (C) 2001-2016 Free Software Foundation, Inc.
2 #
3 #
4 # This is pretty much copy and paste of the unreleased autoconf macros
5 # (where it is named AC_PROG_CXX_CXX11). Once we are dependent on
6 # autoconf version with that macro, we can simply change to use that
7 # one instead. Copied from autoconf commit 04be2b7a (2016/02/06)
8 #
9 #
10 # This file is part of Autoconf. This program is free
11 # software; you can redistribute it and/or modify it under the
12 # terms of the GNU General Public License as published by the
13 # Free Software Foundation, either version 3 of the License, or
14 # (at your option) any later version.
15 #
16 # This program is distributed in the hope that it will be useful,
17 # but WITHOUT ANY WARRANTY; without even the implied warranty of
18 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 # GNU General Public License for more details.
20 #
21 # You should have received a copy of the GNU General Public License
22 # along with this program; if not, see <http://www.gnu.org/licenses/>.
23
24 # OCTAVE_PROG_CC_C11 ([ACTION-IF-AVAILABLE], [ACTION-IF-UNAVAILABLE])
25 # ----------------------------------------------------------------
26 # If the C compiler is not in ISO C11 mode by default, try to add an
27 # option to output variable CC to make it so. This macro tries
28 # various options that select ISO C11 on some system or another. It
29 # considers the compiler to be in ISO C11 mode if it handles _Alignas,
30 # _Alignof, _Noreturn, _Static_assert, UTF-8 string literals,
31 # duplicate typedefs, and anonymous structures and unions.
32 AC_DEFUN([OCTAVE_PROG_CC_C11],
33 [_OCTAVE_C_STD_TRY([c11],
34 [_OCTAVE_C_C99_TEST_HEADER[
35 // Check _Alignas.
36 char _Alignas (double) aligned_as_double;
37 char _Alignas (0) no_special_alignment;
38 extern char aligned_as_int;
39 char _Alignas (0) _Alignas (int) aligned_as_int;
40
41 // Check _Alignof.
42 enum
43 {
44 int_alignment = _Alignof (int),
45 int_array_alignment = _Alignof (int[100]),
46 char_alignment = _Alignof (char)
47 };
48 _Static_assert (0 < -_Alignof (int), "_Alignof is signed");
49
50 // Check _Noreturn.
51 int _Noreturn does_not_return (void) { for (;;) continue; }
52
53 // Check _Static_assert.
54 struct test_static_assert
55 {
56 int x;
57 _Static_assert (sizeof (int) <= sizeof (long int),
58 "_Static_assert does not work in struct");
59 long int y;
60 };
61
62 // Check UTF-8 literals.
63 #define u8 syntax error!
64 char const utf8_literal[] = u8"happens to be ASCII" "another string";
65
66 // Check duplicate typedefs.
67 typedef long *long_ptr;
68 typedef long int *long_ptr;
69 typedef long_ptr long_ptr;
70
71 // Anonymous structures and unions -- taken from C11 6.7.2.1 Example 1.
72 struct anonymous
73 {
74 union {
75 struct { int i; int j; };
76 struct { int k; long int l; } w;
77 };
78 int m;
79 } v1;
80 ]],
81 [_OCTAVE_C_C99_TEST_BODY[
82 v1.i = 2;
83 v1.w.k = 5;
84 _Static_assert (&v1.i == &v1.w.k, "Anonymous union alignment botch");
85 ]],
86 dnl Try
87 dnl GCC -std=gnu11 (unused restrictive mode: -std=c11)
88 dnl with extended modes being tried first.
89 dnl
90 dnl Do not try -qlanglvl=extc1x, because IBM XL C V12.1 (the latest version as
91 dnl of September 2012) does not pass the C11 test. For now, try extc1x when
92 dnl compiling the C99 test instead, since it enables _Static_assert and
93 dnl _Noreturn, which is a win. If -qlanglvl=extc11 or -qlanglvl=extc1x passes
94 dnl the C11 test in some future version of IBM XL C, we'll add it here,
95 dnl preferably extc11.
96 [[-std=gnu11]], [$1], [$2])[]dnl
97 ])# OCTAVE_PROG_CC_C11
98
99
100 # _OCTAVE_C_STD_TRY(STANDARD, TEST-PROLOGUE, TEST-BODY, OPTION-LIST,
101 # ACTION-IF-AVAILABLE, ACTION-IF-UNAVAILABLE)
102 # --------------------------------------------------------------
103 # Check whether the C compiler accepts features of STANDARD (e.g `c89', `c99')
104 # by trying to compile a program of TEST-PROLOGUE and TEST-BODY. If this fails,
105 # try again with each compiler option in the space-separated OPTION-LIST; if one
106 # helps, append it to CC. If eventually successful, run ACTION-IF-AVAILABLE,
107 # else ACTION-IF-UNAVAILABLE.
108 AC_DEFUN([_OCTAVE_C_STD_TRY],
109 [AC_MSG_CHECKING([for $CC option to enable ]m4_translit($1, [c], [C])[ features])
110 AC_CACHE_VAL(ac_cv_prog_cc_$1,
111 [ac_cv_prog_cc_$1=no
112 ac_save_CC=$CC
113 AC_LANG_CONFTEST([AC_LANG_PROGRAM([$2], [$3])])
114 for ac_arg in '' $4
115 do
116 CC="$ac_save_CC $ac_arg"
117 _AC_COMPILE_IFELSE([], [ac_cv_prog_cc_$1=$ac_arg])
118 test "x$ac_cv_prog_cc_$1" != "xno" && break
119 done
120 rm -f conftest.$ac_ext
121 CC=$ac_save_CC
122 ])# AC_CACHE_VAL
123 ac_prog_cc_stdc_options=
124 case "x$ac_cv_prog_cc_$1" in
125 x)
126 AC_MSG_RESULT([none needed]) ;;
127 xno)
128 AC_MSG_RESULT([unsupported]) ;;
129 *)
130 ac_prog_cc_stdc_options=" $ac_cv_prog_cc_$1"
131 CC=$CC$ac_prog_cc_stdc_options
132 AC_MSG_RESULT([$ac_cv_prog_cc_$1]) ;;
133 esac
134 AS_IF([test "x$ac_cv_prog_cc_$1" != xno], [$5], [$6])
135 ])# _OCTAVE_C_STD_TRY
136
137 # _OCTAVE_C_C99_TEST_HEADER
138 # ---------------------
139 # A C header suitable for testing for C99.
140 AC_DEFUN([_OCTAVE_C_C99_TEST_HEADER],
141 [[#include <stdarg.h>
142 #include <stdbool.h>
143 #include <stdlib.h>
144 #include <wchar.h>
145 #include <stdio.h>
146
147 // Check varargs macros. These examples are taken from C99 6.10.3.5.
148 #define debug(...) fprintf (stderr, __VA_ARGS__)
149 #define showlist(...) puts (#__VA_ARGS__)
150 #define report(test,...) ((test) ? puts (#test) : printf (__VA_ARGS__))
151 static void
152 test_varargs_macros (void)
153 {
154 int x = 1234;
155 int y = 5678;
156 debug ("Flag");
157 debug ("X = %d\n", x);
158 showlist (The first, second, and third items.);
159 report (x>y, "x is %d but y is %d", x, y);
160 }
161
162 // Check long long types.
163 #define BIG64 18446744073709551615ull
164 #define BIG32 4294967295ul
165 #define BIG_OK (BIG64 / BIG32 == 4294967297ull && BIG64 % BIG32 == 0)
166 #if !BIG_OK
167 your preprocessor is broken;
168 #endif
169 #if BIG_OK
170 #else
171 your preprocessor is broken;
172 #endif
173 static long long int bignum = -9223372036854775807LL;
174 static unsigned long long int ubignum = BIG64;
175
176 struct incomplete_array
177 {
178 int datasize;
179 double data[];
180 };
181
182 struct named_init {
183 int number;
184 const wchar_t *name;
185 double average;
186 };
187
188 typedef const char *ccp;
189
190 static inline int
191 test_restrict (ccp restrict text)
192 {
193 // See if C++-style comments work.
194 // Iterate through items via the restricted pointer.
195 // Also check for declarations in for loops.
196 for (unsigned int i = 0; *(text+i) != '\0'; ++i)
197 continue;
198 return 0;
199 }
200
201 // Check varargs and va_copy.
202 static bool
203 test_varargs (const char *format, ...)
204 {
205 va_list args;
206 va_start (args, format);
207 va_list args_copy;
208 va_copy (args_copy, args);
209
210 const char *str = "";
211 int number = 0;
212 float fnumber = 0;
213
214 while (*format)
215 {
216 switch (*format++)
217 {
218 case 's': // string
219 str = va_arg (args_copy, const char *);
220 break;
221 case 'd': // int
222 number = va_arg (args_copy, int);
223 break;
224 case 'f': // float
225 fnumber = va_arg (args_copy, double);
226 break;
227 default:
228 break;
229 }
230 }
231 va_end (args_copy);
232 va_end (args);
233
234 return *str && number && fnumber;
235 }]])# _OCTAVE_C_C99_TEST_HEADER
236
237 # _OCTAVE_C_C99_TEST_BODY
238 # -------------------
239 # A C body suitable for testing for C99, assuming the corresponding header.
240 AC_DEFUN([_OCTAVE_C_C99_TEST_BODY],
241 [[
242 // Check bool.
243 _Bool success = false;
244
245 // Check restrict.
246 if (test_restrict ("String literal") == 0)
247 success = true;
248 char *restrict newvar = "Another string";
249
250 // Check varargs.
251 success &= test_varargs ("s, d' f .", "string", 65, 34.234);
252 test_varargs_macros ();
253
254 // Check flexible array members.
255 struct incomplete_array *ia =
256 malloc (sizeof (struct incomplete_array) + (sizeof (double) * 10));
257 ia->datasize = 10;
258 for (int i = 0; i < ia->datasize; ++i)
259 ia->data[i] = i * 1.234;
260
261 // Check named initializers.
262 struct named_init ni = {
263 .number = 34,
264 .name = L"Test wide string",
265 .average = 543.34343,
266 };
267
268 ni.number = 58;
269
270 int dynamic_array[ni.number];
271 dynamic_array[ni.number - 1] = 543;
272
273 // work around unused variable warnings
274 return (!success || bignum == 0LL || ubignum == 0uLL || newvar[0] == 'x'
275 || dynamic_array[ni.number - 1] != 543);
276 ]])