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author | Mathias Gumz <akira@fluxbox.org> | 2016-11-05 21:34:21 (GMT) |
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committer | Mathias Gumz <akira@fluxbox.org> | 2016-11-05 21:38:47 (GMT) |
commit | 61e951617ce7983cfb6ba476d0db290bfd0a5c3e (patch) | |
tree | a1b9ae6f411fb9260997e6d6477e5ff46fb988ec /m4/ax_cxx_compile_stdcxx.m4 | |
parent | 4bab7afaa4943bb627c25ec4e55e383c39dd14bd (diff) | |
download | fluxbox-61e951617ce7983cfb6ba476d0db290bfd0a5c3e.zip fluxbox-61e951617ce7983cfb6ba476d0db290bfd0a5c3e.tar.bz2 |
add automake helpers to enforce --std=cxx11
switching to std::unique_ptr<> in 52c9f62 caused some trouble for
users of "older" compilers: they needed to add the --std=cxx11 flag
by hand. to make life more convenient, m4/ax_cxx_compile_stdcxx.m4
and m4/ax_cxx_compile_stdcxx_11.m4 are added to do the right thing.
in my tests, the last "good" compiler is gcc-4.8, gcc-4.7 does not
support the required c++11 standard.
clang++-3.5 also works.
Diffstat (limited to 'm4/ax_cxx_compile_stdcxx.m4')
-rw-r--r-- | m4/ax_cxx_compile_stdcxx.m4 | 562 |
1 files changed, 562 insertions, 0 deletions
diff --git a/m4/ax_cxx_compile_stdcxx.m4 b/m4/ax_cxx_compile_stdcxx.m4 new file mode 100644 index 0000000..2c18e49 --- /dev/null +++ b/m4/ax_cxx_compile_stdcxx.m4 | |||
@@ -0,0 +1,562 @@ | |||
1 | # =========================================================================== | ||
2 | # http://www.gnu.org/software/autoconf-archive/ax_cxx_compile_stdcxx.html | ||
3 | # =========================================================================== | ||
4 | # | ||
5 | # SYNOPSIS | ||
6 | # | ||
7 | # AX_CXX_COMPILE_STDCXX(VERSION, [ext|noext], [mandatory|optional]) | ||
8 | # | ||
9 | # DESCRIPTION | ||
10 | # | ||
11 | # Check for baseline language coverage in the compiler for the specified | ||
12 | # version of the C++ standard. If necessary, add switches to CXX and | ||
13 | # CXXCPP to enable support. VERSION may be '11' (for the C++11 standard) | ||
14 | # or '14' (for the C++14 standard). | ||
15 | # | ||
16 | # The second argument, if specified, indicates whether you insist on an | ||
17 | # extended mode (e.g. -std=gnu++11) or a strict conformance mode (e.g. | ||
18 | # -std=c++11). If neither is specified, you get whatever works, with | ||
19 | # preference for an extended mode. | ||
20 | # | ||
21 | # The third argument, if specified 'mandatory' or if left unspecified, | ||
22 | # indicates that baseline support for the specified C++ standard is | ||
23 | # required and that the macro should error out if no mode with that | ||
24 | # support is found. If specified 'optional', then configuration proceeds | ||
25 | # regardless, after defining HAVE_CXX${VERSION} if and only if a | ||
26 | # supporting mode is found. | ||
27 | # | ||
28 | # LICENSE | ||
29 | # | ||
30 | # Copyright (c) 2008 Benjamin Kosnik <bkoz@redhat.com> | ||
31 | # Copyright (c) 2012 Zack Weinberg <zackw@panix.com> | ||
32 | # Copyright (c) 2013 Roy Stogner <roystgnr@ices.utexas.edu> | ||
33 | # Copyright (c) 2014, 2015 Google Inc.; contributed by Alexey Sokolov <sokolov@google.com> | ||
34 | # Copyright (c) 2015 Paul Norman <penorman@mac.com> | ||
35 | # Copyright (c) 2015 Moritz Klammler <moritz@klammler.eu> | ||
36 | # | ||
37 | # Copying and distribution of this file, with or without modification, are | ||
38 | # permitted in any medium without royalty provided the copyright notice | ||
39 | # and this notice are preserved. This file is offered as-is, without any | ||
40 | # warranty. | ||
41 | |||
42 | #serial 4 | ||
43 | |||
44 | dnl This macro is based on the code from the AX_CXX_COMPILE_STDCXX_11 macro | ||
45 | dnl (serial version number 13). | ||
46 | |||
47 | AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl | ||
48 | m4_if([$1], [11], [], | ||
49 | [$1], [14], [], | ||
50 | [$1], [17], [m4_fatal([support for C++17 not yet implemented in AX_CXX_COMPILE_STDCXX])], | ||
51 | [m4_fatal([invalid first argument `$1' to AX_CXX_COMPILE_STDCXX])])dnl | ||
52 | m4_if([$2], [], [], | ||
53 | [$2], [ext], [], | ||
54 | [$2], [noext], [], | ||
55 | [m4_fatal([invalid second argument `$2' to AX_CXX_COMPILE_STDCXX])])dnl | ||
56 | m4_if([$3], [], [ax_cxx_compile_cxx$1_required=true], | ||
57 | [$3], [mandatory], [ax_cxx_compile_cxx$1_required=true], | ||
58 | [$3], [optional], [ax_cxx_compile_cxx$1_required=false], | ||
59 | [m4_fatal([invalid third argument `$3' to AX_CXX_COMPILE_STDCXX])]) | ||
60 | AC_LANG_PUSH([C++])dnl | ||
61 | ac_success=no | ||
62 | AC_CACHE_CHECK(whether $CXX supports C++$1 features by default, | ||
63 | ax_cv_cxx_compile_cxx$1, | ||
64 | [AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_testbody_$1])], | ||
65 | [ax_cv_cxx_compile_cxx$1=yes], | ||
66 | [ax_cv_cxx_compile_cxx$1=no])]) | ||
67 | if test x$ax_cv_cxx_compile_cxx$1 = xyes; then | ||
68 | ac_success=yes | ||
69 | fi | ||
70 | |||
71 | m4_if([$2], [noext], [], [dnl | ||
72 | if test x$ac_success = xno; then | ||
73 | for switch in -std=gnu++$1 -std=gnu++0x; do | ||
74 | cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx$1_$switch]) | ||
75 | AC_CACHE_CHECK(whether $CXX supports C++$1 features with $switch, | ||
76 | $cachevar, | ||
77 | [ac_save_CXX="$CXX" | ||
78 | CXX="$CXX $switch" | ||
79 | AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_testbody_$1])], | ||
80 | [eval $cachevar=yes], | ||
81 | [eval $cachevar=no]) | ||
82 | CXX="$ac_save_CXX"]) | ||
83 | if eval test x\$$cachevar = xyes; then | ||
84 | CXX="$CXX $switch" | ||
85 | if test -n "$CXXCPP" ; then | ||
86 | CXXCPP="$CXXCPP $switch" | ||
87 | fi | ||
88 | ac_success=yes | ||
89 | break | ||
90 | fi | ||
91 | done | ||
92 | fi]) | ||
93 | |||
94 | m4_if([$2], [ext], [], [dnl | ||
95 | if test x$ac_success = xno; then | ||
96 | dnl HP's aCC needs +std=c++11 according to: | ||
97 | dnl http://h21007.www2.hp.com/portal/download/files/unprot/aCxx/PDF_Release_Notes/769149-001.pdf | ||
98 | dnl Cray's crayCC needs "-h std=c++11" | ||
99 | for switch in -std=c++$1 -std=c++0x +std=c++$1 "-h std=c++$1"; do | ||
100 | cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx$1_$switch]) | ||
101 | AC_CACHE_CHECK(whether $CXX supports C++$1 features with $switch, | ||
102 | $cachevar, | ||
103 | [ac_save_CXX="$CXX" | ||
104 | CXX="$CXX $switch" | ||
105 | AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_testbody_$1])], | ||
106 | [eval $cachevar=yes], | ||
107 | [eval $cachevar=no]) | ||
108 | CXX="$ac_save_CXX"]) | ||
109 | if eval test x\$$cachevar = xyes; then | ||
110 | CXX="$CXX $switch" | ||
111 | if test -n "$CXXCPP" ; then | ||
112 | CXXCPP="$CXXCPP $switch" | ||
113 | fi | ||
114 | ac_success=yes | ||
115 | break | ||
116 | fi | ||
117 | done | ||
118 | fi]) | ||
119 | AC_LANG_POP([C++]) | ||
120 | if test x$ax_cxx_compile_cxx$1_required = xtrue; then | ||
121 | if test x$ac_success = xno; then | ||
122 | AC_MSG_ERROR([*** A compiler with support for C++$1 language features is required.]) | ||
123 | fi | ||
124 | fi | ||
125 | if test x$ac_success = xno; then | ||
126 | HAVE_CXX$1=0 | ||
127 | AC_MSG_NOTICE([No compiler with C++$1 support was found]) | ||
128 | else | ||
129 | HAVE_CXX$1=1 | ||
130 | AC_DEFINE(HAVE_CXX$1,1, | ||
131 | [define if the compiler supports basic C++$1 syntax]) | ||
132 | fi | ||
133 | AC_SUBST(HAVE_CXX$1) | ||
134 | ]) | ||
135 | |||
136 | |||
137 | dnl Test body for checking C++11 support | ||
138 | |||
139 | m4_define([_AX_CXX_COMPILE_STDCXX_testbody_11], | ||
140 | _AX_CXX_COMPILE_STDCXX_testbody_new_in_11 | ||
141 | ) | ||
142 | |||
143 | |||
144 | dnl Test body for checking C++14 support | ||
145 | |||
146 | m4_define([_AX_CXX_COMPILE_STDCXX_testbody_14], | ||
147 | _AX_CXX_COMPILE_STDCXX_testbody_new_in_11 | ||
148 | _AX_CXX_COMPILE_STDCXX_testbody_new_in_14 | ||
149 | ) | ||
150 | |||
151 | |||
152 | dnl Tests for new features in C++11 | ||
153 | |||
154 | m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_11], [[ | ||
155 | |||
156 | // If the compiler admits that it is not ready for C++11, why torture it? | ||
157 | // Hopefully, this will speed up the test. | ||
158 | |||
159 | #ifndef __cplusplus | ||
160 | |||
161 | #error "This is not a C++ compiler" | ||
162 | |||
163 | #elif __cplusplus < 201103L | ||
164 | |||
165 | #error "This is not a C++11 compiler" | ||
166 | |||
167 | #else | ||
168 | |||
169 | namespace cxx11 | ||
170 | { | ||
171 | |||
172 | namespace test_static_assert | ||
173 | { | ||
174 | |||
175 | template <typename T> | ||
176 | struct check | ||
177 | { | ||
178 | static_assert(sizeof(int) <= sizeof(T), "not big enough"); | ||
179 | }; | ||
180 | |||
181 | } | ||
182 | |||
183 | namespace test_final_override | ||
184 | { | ||
185 | |||
186 | struct Base | ||
187 | { | ||
188 | virtual void f() {} | ||
189 | }; | ||
190 | |||
191 | struct Derived : public Base | ||
192 | { | ||
193 | virtual void f() override {} | ||
194 | }; | ||
195 | |||
196 | } | ||
197 | |||
198 | namespace test_double_right_angle_brackets | ||
199 | { | ||
200 | |||
201 | template < typename T > | ||
202 | struct check {}; | ||
203 | |||
204 | typedef check<void> single_type; | ||
205 | typedef check<check<void>> double_type; | ||
206 | typedef check<check<check<void>>> triple_type; | ||
207 | typedef check<check<check<check<void>>>> quadruple_type; | ||
208 | |||
209 | } | ||
210 | |||
211 | namespace test_decltype | ||
212 | { | ||
213 | |||
214 | int | ||
215 | f() | ||
216 | { | ||
217 | int a = 1; | ||
218 | decltype(a) b = 2; | ||
219 | return a + b; | ||
220 | } | ||
221 | |||
222 | } | ||
223 | |||
224 | namespace test_type_deduction | ||
225 | { | ||
226 | |||
227 | template < typename T1, typename T2 > | ||
228 | struct is_same | ||
229 | { | ||
230 | static const bool value = false; | ||
231 | }; | ||
232 | |||
233 | template < typename T > | ||
234 | struct is_same<T, T> | ||
235 | { | ||
236 | static const bool value = true; | ||
237 | }; | ||
238 | |||
239 | template < typename T1, typename T2 > | ||
240 | auto | ||
241 | add(T1 a1, T2 a2) -> decltype(a1 + a2) | ||
242 | { | ||
243 | return a1 + a2; | ||
244 | } | ||
245 | |||
246 | int | ||
247 | test(const int c, volatile int v) | ||
248 | { | ||
249 | static_assert(is_same<int, decltype(0)>::value == true, ""); | ||
250 | static_assert(is_same<int, decltype(c)>::value == false, ""); | ||
251 | static_assert(is_same<int, decltype(v)>::value == false, ""); | ||
252 | auto ac = c; | ||
253 | auto av = v; | ||
254 | auto sumi = ac + av + 'x'; | ||
255 | auto sumf = ac + av + 1.0; | ||
256 | static_assert(is_same<int, decltype(ac)>::value == true, ""); | ||
257 | static_assert(is_same<int, decltype(av)>::value == true, ""); | ||
258 | static_assert(is_same<int, decltype(sumi)>::value == true, ""); | ||
259 | static_assert(is_same<int, decltype(sumf)>::value == false, ""); | ||
260 | static_assert(is_same<int, decltype(add(c, v))>::value == true, ""); | ||
261 | return (sumf > 0.0) ? sumi : add(c, v); | ||
262 | } | ||
263 | |||
264 | } | ||
265 | |||
266 | namespace test_noexcept | ||
267 | { | ||
268 | |||
269 | int f() { return 0; } | ||
270 | int g() noexcept { return 0; } | ||
271 | |||
272 | static_assert(noexcept(f()) == false, ""); | ||
273 | static_assert(noexcept(g()) == true, ""); | ||
274 | |||
275 | } | ||
276 | |||
277 | namespace test_constexpr | ||
278 | { | ||
279 | |||
280 | template < typename CharT > | ||
281 | unsigned long constexpr | ||
282 | strlen_c_r(const CharT *const s, const unsigned long acc) noexcept | ||
283 | { | ||
284 | return *s ? strlen_c_r(s + 1, acc + 1) : acc; | ||
285 | } | ||
286 | |||
287 | template < typename CharT > | ||
288 | unsigned long constexpr | ||
289 | strlen_c(const CharT *const s) noexcept | ||
290 | { | ||
291 | return strlen_c_r(s, 0UL); | ||
292 | } | ||
293 | |||
294 | static_assert(strlen_c("") == 0UL, ""); | ||
295 | static_assert(strlen_c("1") == 1UL, ""); | ||
296 | static_assert(strlen_c("example") == 7UL, ""); | ||
297 | static_assert(strlen_c("another\0example") == 7UL, ""); | ||
298 | |||
299 | } | ||
300 | |||
301 | namespace test_rvalue_references | ||
302 | { | ||
303 | |||
304 | template < int N > | ||
305 | struct answer | ||
306 | { | ||
307 | static constexpr int value = N; | ||
308 | }; | ||
309 | |||
310 | answer<1> f(int&) { return answer<1>(); } | ||
311 | answer<2> f(const int&) { return answer<2>(); } | ||
312 | answer<3> f(int&&) { return answer<3>(); } | ||
313 | |||
314 | void | ||
315 | test() | ||
316 | { | ||
317 | int i = 0; | ||
318 | const int c = 0; | ||
319 | static_assert(decltype(f(i))::value == 1, ""); | ||
320 | static_assert(decltype(f(c))::value == 2, ""); | ||
321 | static_assert(decltype(f(0))::value == 3, ""); | ||
322 | } | ||
323 | |||
324 | } | ||
325 | |||
326 | namespace test_uniform_initialization | ||
327 | { | ||
328 | |||
329 | struct test | ||
330 | { | ||
331 | static const int zero {}; | ||
332 | static const int one {1}; | ||
333 | }; | ||
334 | |||
335 | static_assert(test::zero == 0, ""); | ||
336 | static_assert(test::one == 1, ""); | ||
337 | |||
338 | } | ||
339 | |||
340 | namespace test_lambdas | ||
341 | { | ||
342 | |||
343 | void | ||
344 | test1() | ||
345 | { | ||
346 | auto lambda1 = [](){}; | ||
347 | auto lambda2 = lambda1; | ||
348 | lambda1(); | ||
349 | lambda2(); | ||
350 | } | ||
351 | |||
352 | int | ||
353 | test2() | ||
354 | { | ||
355 | auto a = [](int i, int j){ return i + j; }(1, 2); | ||
356 | auto b = []() -> int { return '0'; }(); | ||
357 | auto c = [=](){ return a + b; }(); | ||
358 | auto d = [&](){ return c; }(); | ||
359 | auto e = [a, &b](int x) mutable { | ||
360 | const auto identity = [](int y){ return y; }; | ||
361 | for (auto i = 0; i < a; ++i) | ||
362 | a += b--; | ||
363 | return x + identity(a + b); | ||
364 | }(0); | ||
365 | return a + b + c + d + e; | ||
366 | } | ||
367 | |||
368 | int | ||
369 | test3() | ||
370 | { | ||
371 | const auto nullary = [](){ return 0; }; | ||
372 | const auto unary = [](int x){ return x; }; | ||
373 | using nullary_t = decltype(nullary); | ||
374 | using unary_t = decltype(unary); | ||
375 | const auto higher1st = [](nullary_t f){ return f(); }; | ||
376 | const auto higher2nd = [unary](nullary_t f1){ | ||
377 | return [unary, f1](unary_t f2){ return f2(unary(f1())); }; | ||
378 | }; | ||
379 | return higher1st(nullary) + higher2nd(nullary)(unary); | ||
380 | } | ||
381 | |||
382 | } | ||
383 | |||
384 | namespace test_variadic_templates | ||
385 | { | ||
386 | |||
387 | template <int...> | ||
388 | struct sum; | ||
389 | |||
390 | template <int N0, int... N1toN> | ||
391 | struct sum<N0, N1toN...> | ||
392 | { | ||
393 | static constexpr auto value = N0 + sum<N1toN...>::value; | ||
394 | }; | ||
395 | |||
396 | template <> | ||
397 | struct sum<> | ||
398 | { | ||
399 | static constexpr auto value = 0; | ||
400 | }; | ||
401 | |||
402 | static_assert(sum<>::value == 0, ""); | ||
403 | static_assert(sum<1>::value == 1, ""); | ||
404 | static_assert(sum<23>::value == 23, ""); | ||
405 | static_assert(sum<1, 2>::value == 3, ""); | ||
406 | static_assert(sum<5, 5, 11>::value == 21, ""); | ||
407 | static_assert(sum<2, 3, 5, 7, 11, 13>::value == 41, ""); | ||
408 | |||
409 | } | ||
410 | |||
411 | // http://stackoverflow.com/questions/13728184/template-aliases-and-sfinae | ||
412 | // Clang 3.1 fails with headers of libstd++ 4.8.3 when using std::function | ||
413 | // because of this. | ||
414 | namespace test_template_alias_sfinae | ||
415 | { | ||
416 | |||
417 | struct foo {}; | ||
418 | |||
419 | template<typename T> | ||
420 | using member = typename T::member_type; | ||
421 | |||
422 | template<typename T> | ||
423 | void func(...) {} | ||
424 | |||
425 | template<typename T> | ||
426 | void func(member<T>*) {} | ||
427 | |||
428 | void test(); | ||
429 | |||
430 | void test() { func<foo>(0); } | ||
431 | |||
432 | } | ||
433 | |||
434 | } // namespace cxx11 | ||
435 | |||
436 | #endif // __cplusplus >= 201103L | ||
437 | |||
438 | ]]) | ||
439 | |||
440 | |||
441 | dnl Tests for new features in C++14 | ||
442 | |||
443 | m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_14], [[ | ||
444 | |||
445 | // If the compiler admits that it is not ready for C++14, why torture it? | ||
446 | // Hopefully, this will speed up the test. | ||
447 | |||
448 | #ifndef __cplusplus | ||
449 | |||
450 | #error "This is not a C++ compiler" | ||
451 | |||
452 | #elif __cplusplus < 201402L | ||
453 | |||
454 | #error "This is not a C++14 compiler" | ||
455 | |||
456 | #else | ||
457 | |||
458 | namespace cxx14 | ||
459 | { | ||
460 | |||
461 | namespace test_polymorphic_lambdas | ||
462 | { | ||
463 | |||
464 | int | ||
465 | test() | ||
466 | { | ||
467 | const auto lambda = [](auto&&... args){ | ||
468 | const auto istiny = [](auto x){ | ||
469 | return (sizeof(x) == 1UL) ? 1 : 0; | ||
470 | }; | ||
471 | const int aretiny[] = { istiny(args)... }; | ||
472 | return aretiny[0]; | ||
473 | }; | ||
474 | return lambda(1, 1L, 1.0f, '1'); | ||
475 | } | ||
476 | |||
477 | } | ||
478 | |||
479 | namespace test_binary_literals | ||
480 | { | ||
481 | |||
482 | constexpr auto ivii = 0b0000000000101010; | ||
483 | static_assert(ivii == 42, "wrong value"); | ||
484 | |||
485 | } | ||
486 | |||
487 | namespace test_generalized_constexpr | ||
488 | { | ||
489 | |||
490 | template < typename CharT > | ||
491 | constexpr unsigned long | ||
492 | strlen_c(const CharT *const s) noexcept | ||
493 | { | ||
494 | auto length = 0UL; | ||
495 | for (auto p = s; *p; ++p) | ||
496 | ++length; | ||
497 | return length; | ||
498 | } | ||
499 | |||
500 | static_assert(strlen_c("") == 0UL, ""); | ||
501 | static_assert(strlen_c("x") == 1UL, ""); | ||
502 | static_assert(strlen_c("test") == 4UL, ""); | ||
503 | static_assert(strlen_c("another\0test") == 7UL, ""); | ||
504 | |||
505 | } | ||
506 | |||
507 | namespace test_lambda_init_capture | ||
508 | { | ||
509 | |||
510 | int | ||
511 | test() | ||
512 | { | ||
513 | auto x = 0; | ||
514 | const auto lambda1 = [a = x](int b){ return a + b; }; | ||
515 | const auto lambda2 = [a = lambda1(x)](){ return a; }; | ||
516 | return lambda2(); | ||
517 | } | ||
518 | |||
519 | } | ||
520 | |||
521 | namespace test_digit_seperators | ||
522 | { | ||
523 | |||
524 | constexpr auto ten_million = 100'000'000; | ||
525 | static_assert(ten_million == 100000000, ""); | ||
526 | |||
527 | } | ||
528 | |||
529 | namespace test_return_type_deduction | ||
530 | { | ||
531 | |||
532 | auto f(int& x) { return x; } | ||
533 | decltype(auto) g(int& x) { return x; } | ||
534 | |||
535 | template < typename T1, typename T2 > | ||
536 | struct is_same | ||
537 | { | ||
538 | static constexpr auto value = false; | ||
539 | }; | ||
540 | |||
541 | template < typename T > | ||
542 | struct is_same<T, T> | ||
543 | { | ||
544 | static constexpr auto value = true; | ||
545 | }; | ||
546 | |||
547 | int | ||
548 | test() | ||
549 | { | ||
550 | auto x = 0; | ||
551 | static_assert(is_same<int, decltype(f(x))>::value, ""); | ||
552 | static_assert(is_same<int&, decltype(g(x))>::value, ""); | ||
553 | return x; | ||
554 | } | ||
555 | |||
556 | } | ||
557 | |||
558 | } // namespace cxx14 | ||
559 | |||
560 | #endif // __cplusplus >= 201402L | ||
561 | |||
562 | ]]) | ||