AC_PROG_CXX([gcc cl KCC CC cxx cc++ xlC aCC c++ g++])
@end example
+If necessary, add an option to output variable @code{CXX} to enable
+support for ISO Standard C++ features with extensions. Prefer the
+newest C++ standard that is supported. Currently the newest standard is
+ISO C++11, with ISO C++98 being the previous standard. After calling
+this macro you can check whether the C++ compiler has been set to accept
+Standard C++; if not, the shell variable @code{ac_cv_prog_cxx_stdcxx} is
+set to @samp{no}. If the C++ compiler will not accept C++11, the shell
+variable @code{ac_cv_prog_cxx_cxx11} is set to @samp{no}, and if it will
+not accept C++98, the shell variable @code{ac_cv_prog_cxx_cxx98} is set
+to @samp{no}.
+
+When attempting to add compiler options, prefer extended functionality
+to strict conformance: the goal is to enable whatever standard features
+that are available, not to check for full conformance to the standard or
+to prohibit incompatible extensions. Test for C++11 support by checking
+for the language features @code{auto}, @code{constexpr},
+@code{decltype}, @code{default}ed and @code{delete}ed constructors,
+delegate constructors, @code{final}, initializer lists, lambda
+functions, @code{nullptr}, @code{override}, range-based for loops,
+template brackets without spaces and unicode literals, and library
+features @code{std::array}, @code{std::shared_ptr},
+@code{std::weak_ptr}, @code{std::regex} and @code{std::tuple}. Test for
+C++98 support using basic features of the @code{std} namespace including
+@code{std::string}, containers (@code{std::list}, @code{std::map},
+@code{std::set}, @code{std::vector}), streams (fstreams, iostreams,
+stringstreams, iomanip), @code{std::pair}, exceptions (@code{try},
+@code{catch} and @code{std::runtime_error}) and algorithms. Tests for
+more recent standards include all the tests for older standards.
+
If using the GNU C++ compiler, set shell variable @code{GXX} to
@samp{yes}. If output variable @code{CXXFLAGS} was not already set, set
it to @option{-g -O2} for the GNU C++ compiler (@option{-O2} on
compilers. If your package does not like this default, then it is
acceptable to insert the line @samp{: $@{CXXFLAGS=""@}} after @code{AC_INIT}
and before @code{AC_PROG_CXX} to select an empty default instead.
-
@end defmac
@defmac AC_PROG_CXXCPP
GXX=
fi
_AC_PROG_CXX_G
+_AC_PROG_CXX_CXX11([ac_prog_cxx_stdcxx=cxx11
+ ac_cv_prog_cxx_stdcxx=$ac_cv_prog_cxx_cxx11
+ ac_cv_prog_cxx_cxx98=$ac_cv_prog_cxx_cxx11],
+ [_AC_PROG_CXX_CXX98([ac_prog_cxx_stdcxx=cxx98
+ ac_cv_prog_cxx_stdcxx=$ac_cv_prog_cxx_cxx98],
+ [ac_prog_cxx_stdcxx=no
+ ac_cv_prog_cxx_stdcxx=no])])
AC_LANG_POP(C++)dnl
])# AC_PROG_CXX
fi
AC_SUBST([OPENMP_]_AC_LANG_PREFIX[FLAGS])
])
+
+# _AC_CXX_STD_TRY(STANDARD, TEST-PROLOGUE, TEST-BODY, OPTION-LIST,
+# ACTION-IF-AVAILABLE, ACTION-IF-UNAVAILABLE)
+# ----------------------------------------------------------------
+# Check whether the C++ compiler accepts features of STANDARD (e.g
+# `cxx98', `cxx11') by trying to compile a program of TEST-PROLOGUE
+# and TEST-BODY. If this fails, try again with each compiler option
+# in the space-separated OPTION-LIST; if one helps, append it to CXX.
+# If eventually successful, run ACTION-IF-AVAILABLE, else
+# ACTION-IF-UNAVAILABLE.
+AC_DEFUN([_AC_CXX_STD_TRY],
+[AC_MSG_CHECKING([for $CXX option to enable ]m4_translit(m4_translit($1, [x], [+]), [a-z], [A-Z])[ features])
+AC_LANG_PUSH(C++)dnl
+AC_CACHE_VAL(ac_cv_prog_cxx_$1,
+[ac_cv_prog_cxx_$1=no
+ac_save_CXX=$CXX
+AC_LANG_CONFTEST([AC_LANG_PROGRAM([$2], [$3])])
+for ac_arg in '' $4
+do
+ CXX="$ac_save_CXX $ac_arg"
+ _AC_COMPILE_IFELSE([], [ac_cv_prog_cxx_$1=$ac_arg])
+ test "x$ac_cv_prog_cxx_$1" != "xno" && break
+done
+rm -f conftest.$ac_ext
+CXX=$ac_save_CXX
+])# AC_CACHE_VAL
+ac_prog_cxx_stdcxx_options=
+case "x$ac_cv_prog_cxx_$1" in
+ x)
+ AC_MSG_RESULT([none needed]) ;;
+ xno)
+ AC_MSG_RESULT([unsupported]) ;;
+ *)
+ ac_prog_cxx_stdcxx_options=" $ac_cv_prog_cxx_$1"
+ CXX=$CXX$ac_prog_cxx_stdcxx_options
+ AC_MSG_RESULT([$ac_cv_prog_cxx_$1]) ;;
+esac
+AC_LANG_POP(C++)dnl
+AS_IF([test "x$ac_cv_prog_cxx_$1" != xno], [$5], [$6])
+])# _AC_CXX_STD_TRY
+
+# _AC_CXX_CXX98_TEST_HEADER
+# -------------------------
+# A C++ header suitable for testing for CXX98.
+AC_DEFUN([_AC_CXX_CXX98_TEST_HEADER],
+[[
+#include <algorithm>
+#include <cstdlib>
+#include <fstream>
+#include <iomanip>
+#include <iostream>
+#include <list>
+#include <map>
+#include <set>
+#include <sstream>
+#include <stdexcept>
+#include <string>
+#include <utility>
+#include <vector>
+
+namespace test {
+ typedef std::vector<std::string> string_vec;
+ typedef std::pair<int,bool> map_value;
+ typedef std::map<std::string,map_value> map_type;
+ typedef std::set<int> set_type;
+
+ template<typename T>
+ class printer {
+ public:
+ printer(std::ostringstream& os): os(os) {}
+ void operator() (T elem) { os << elem << std::endl; }
+ private:
+ std::ostringstream& os;
+ };
+}
+]])# _AC_CXX_CXX98_TEST_HEADER
+
+# _AC_CXX_CXX98_TEST_BODY
+# -----------------------
+# A C++ body suitable for testing for CXX98, assuming the corresponding header.
+AC_DEFUN([_AC_CXX_CXX98_TEST_BODY],
+[[
+
+try {
+ // Basic string.
+ std::string teststr("ASCII text");
+ teststr += " string";
+
+ // Simple vector.
+ test::string_vec testvec;
+ testvec.push_back(teststr);
+ testvec.push_back("foo");
+ testvec.push_back("bar");
+ if (testvec.size() != 3) {
+ throw std::runtime_error("Vector size is not 1");
+ }
+
+ // Dump vector into stringstream and obtain string.
+ std::ostringstream os;
+ for (test::string_vec::const_iterator i = testvec.begin();
+ i != testvec.end(); ++i) {
+ if (i + 1 != testvec.end()) {
+ os << teststr << '\n';
+ }
+ }
+ // Check algorithms work.
+ std::for_each(testvec.begin(), testvec.end(), test::printer<std::string>(os));
+ std::string os_out = os.str();
+
+ // Test pair and map.
+ test::map_type testmap;
+ testmap.insert(std::make_pair(std::string("key"),
+ std::make_pair(53,false)));
+
+ // Test set.
+ int values[] = {9, 7, 13, 15, 4, 18, 12, 10, 5, 3, 14, 19, 17, 8, 6, 20, 16, 2, 11, 1};
+ test::set_type testset(values, values + sizeof(values)/sizeof(values[0]));
+ std::list<int> testlist(testset.begin(), testset.end());
+ std::copy(testset.begin(), testset.end(), std::back_inserter(testlist));
+} catch (const std::exception& e) {
+ std::cerr << "Caught exception: " << e.what() << std::endl;
+
+ // Test fstream
+ std::ofstream of("test.txt");
+ of << "Test ASCII text\n" << std::flush;
+ of << "N= " << std::hex << std::setw(8) << std::left << 534 << std::endl;
+ of.close();
+}
+std::exit(0);
+]])
+
+# _AC_CXX_CXX11_TEST_HEADER
+# -------------------------
+# A C++ header suitable for testing for CXX11.
+AC_DEFUN([_AC_CXX_CXX11_TEST_HEADER],
+[[
+#include <deque>
+#include <functional>
+#include <memory>
+#include <tuple>
+#include <array>
+#include <regex>
+#include <iostream>
+
+namespace cxx11test
+{
+ typedef std::shared_ptr<std::string> sptr;
+ typedef std::weak_ptr<std::string> wptr;
+
+ typedef std::tuple<std::string,int,double> tp;
+ typedef std::array<int, 20> int_array;
+
+ constexpr int get_val() { return 20; }
+
+ struct testinit
+ {
+ int i;
+ double d;
+ };
+
+ class delegate {
+ public:
+ delegate(int n) : n(n) {}
+ delegate(): delegate(2354) {}
+
+ virtual int getval() { return this->n; };
+ protected:
+ int n;
+ };
+
+ class overridden : public delegate {
+ public:
+ overridden(int n): delegate(n) {}
+ virtual int getval() override final { return this->n * 2; }
+ };
+
+ class nocopy {
+ public:
+ nocopy(int i): i(i) {}
+ nocopy() = default;
+ nocopy(const nocopy&) = delete;
+ nocopy & operator=(const nocopy&) = delete;
+ private:
+ int i;
+ };
+}
+]])# _AC_CXX_CXX11_TEST_HEADER
+
+# _AC_CXX_CXX11_TEST_BODY
+# -----------------------
+# A C++ body suitable for testing for CXX11, assuming the corresponding header.
+AC_DEFUN([_AC_CXX_CXX11_TEST_BODY],
+[[
+{
+ // Test auto and decltype
+ std::deque<int> d;
+ d.push_front(43);
+ d.push_front(484);
+ d.push_front(3);
+ d.push_front(844);
+ int total = 0;
+ for (auto i = d.begin(); i != d.end(); ++i) { total += *i; }
+
+ auto a1 = 6538;
+ auto a2 = 48573953.4;
+ auto a3 = "String literal";
+
+ decltype(a2) a4 = 34895.034;
+}
+{
+ // Test constexpr
+ short sa[cxx11test::get_val()] = { 0 };
+}
+{
+ // Test initialiser lists
+ cxx11test::testinit il = { 4323, 435234.23544 };
+}
+{
+ // Test range-based for and lambda
+ cxx11test::int_array array = {9, 7, 13, 15, 4, 18, 12, 10, 5, 3, 14, 19, 17, 8, 6, 20, 16, 2, 11, 1};
+ for (int &x : array) { x += 23; }
+ std::for_each(array.begin(), array.end(), [](int v1){ std::cout << v1; });
+}
+{
+ using cxx11test::sptr;
+ using cxx11test::wptr;
+
+ sptr sp(new std::string("ASCII string"));
+ wptr wp(sp);
+ sptr sp2(wp);
+}
+{
+ cxx11test::tp tuple("test", 54, 45.53434);
+ double d = std::get<2>(tuple);
+ std::string s;
+ int i;
+ std::tie(s,i,d) = tuple;
+}
+{
+ static std::regex filename_regex("^_?([a-z0-9_.]+-)+[a-z0-9]+$");
+ std::string testmatch("Test if this string matches");
+ bool match = std::regex_search(testmatch, filename_regex);
+}
+{
+ cxx11test::int_array array = {9, 7, 13, 15, 4, 18, 12, 10, 5, 3, 14, 19, 17, 8, 6, 20, 16, 2, 11, 1};
+ cxx11test::int_array::size_type size = array.size();
+}
+{
+ // Test constructor delegation
+ cxx11test::delegate d1;
+ cxx11test::delegate d2();
+ cxx11test::delegate d3(45);
+}
+{
+ // Test override and final
+ cxx11test::overridden o1(55464);
+}
+{
+ // Test nullptr
+ char *c = nullptr;
+}
+{
+ // Test template brackets
+ std::vector<std::pair<int,char*>> v1;
+}
+{
+ // Unicode literals
+ char *utf8 = u8"UTF-8 string \u2500";
+ char16_t *utf16 = u"UTF-8 string \u2500";
+ char32_t *utf32 = U"UTF-32 string \u2500";
+}
+]])
+
+# _AC_PROG_CXX_CXX98 ([ACTION-IF-AVAILABLE], [ACTION-IF-UNAVAILABLE])
+# -------------------------------------------------------------------
+
+# If the C++ compiler is not in ISO C++98 mode by default, try to add
+# an option to output variable CXX to make it so. This macro tries
+# various options that select ISO C++98 on some system or another. It
+# considers the compiler to be in ISO C++98 mode if it handles basic
+# features of the std namespace including: string, containers (list,
+# map, set, vector), streams (fstreams, iostreams, stringstreams,
+# iomanip), pair, exceptions and algorithms.
+
+
+AC_DEFUN([_AC_PROG_CXX_CXX98],
+[_AC_CXX_STD_TRY([cxx98],
+[_AC_CXX_CXX98_TEST_HEADER],
+[_AC_CXX_CXX98_TEST_BODY],
+dnl Try
+dnl GCC -std=gnu++98 (unused restrictive mode: -std=c++98)
+dnl IBM XL C -qlanglvl=extended
+dnl HP aC++ -AA
+dnl Intel ICC -std=gnu++98
+dnl Solaris N/A (default)
+dnl Tru64 N/A (default, but -std gnu could be used)
+dnl with extended modes being tried first.
+[[-std=gnu++98 -std=c++98 -qlanglvl=extended -AA]], [$1], [$2])[]dnl
+])# _AC_PROG_CXX_CXX98
+
+# _AC_PROG_CXX_CXX11 ([ACTION-IF-AVAILABLE], [ACTION-IF-UNAVAILABLE])
+# -------------------------------------------------------------------
+# If the C++ compiler is not in ISO CXX11 mode by default, try to add
+# an option to output variable CXX to make it so. This macro tries
+# various options that select ISO C++11 on some system or another. It
+# considers the compiler to be in ISO C++11 mode if it handles all the
+# tests from the C++98 checks, plus the following: Language features
+# (auto, constexpr, decltype, default/deleted constructors, delegate
+# constructors, final, initialiser lists, lambda functions, nullptr,
+# override, range-based for loops, template brackets without spaces,
+# unicode literals) and library features (array, memory (shared_ptr,
+# weak_ptr), regex and tuple types).
+AC_DEFUN([_AC_PROG_CXX_CXX11],
+[_AC_CXX_STD_TRY([cxx11],
+[_AC_CXX_CXX11_TEST_HEADER
+_AC_CXX_CXX98_TEST_HEADER],
+[_AC_CXX_CXX11_TEST_BODY
+_AC_CXX_CXX98_TEST_BODY],
+dnl Try
+dnl GCC -std=gnu++11 (unused restrictive mode: -std=c++11) [and 0x variants]
+dnl IBM XL C -qlanglvl=extended0x
+dnl (pre-V12.1; unused restrictive mode: -qlanglvl=stdcxx11)
+dnl HP aC++ -AA
+dnl Intel ICC -std=c++11 -std=c++0x
+dnl Solaris N/A (no support)
+dnl Tru64 N/A (no support)
+dnl with extended modes being tried first.
+[[-std=gnu++11 -std=c++11 -std=gnu++0x -std=c++0x -qlanglvl=extended0x -AA]], [$1], [$2])[]dnl
+])# _AC_PROG_CXX_CXX11
projects / thirdparty / autoconf.git / commitdiff
