From: Pedro Alves Date: Wed, 12 Oct 2016 23:27:45 +0000 (+0100) Subject: gdb: Require C++11 X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=0bcda68539948828795564b35a497dc69c27f768;p=binutils-gdb.git gdb: Require C++11 Use AX_CXX_COMPILE_STDCXX to detect if the compiler supports C++11, and if -std=xxx switches are necessary to enable C++11. We need to tweak AX_CXX_COMPILE_STDCXX a bit though. Pristine upstream AX_CXX_COMPILE_STDCXX appends -std=gnu++11 to CXX directly. That doesn't work for us, because the top level Makefile passes CXX down to subdirs, and that overrides whatever gdb/Makefile may set CXX to. The result would be that a make invocation from the build/gdb/ directory would use "g++ -std=gnu++11" as expected, while a make invocation at the top level would not. So instead of having AX_CXX_COMPILE_STDCXX set CXX directly, tweak it to AC_SUBST a separate variable -- CXX_DIALECT -- and use '$(CXX) (CXX_DIALECT)' to compile/link. Confirmed that this enables C++11 starting with gcc 4.8, the first gcc release with full C++11 support. Also confirmed that configure errors out gracefully with older GCC releases: checking whether /opt/gcc-4.7/bin/g++ supports C++11 features by default... no checking whether /opt/gcc-4.7/bin/g++ supports C++11 features with -std=gnu++11... no checking whether /opt/gcc-4.7/bin/g++ supports C++11 features with -std=gnu++0x... no checking whether /opt/gcc-4.7/bin/g++ supports C++11 features with -std=c++11... no checking whether /opt/gcc-4.7/bin/g++ supports C++11 features with -std=c++0x... no checking whether /opt/gcc-4.7/bin/g++ supports C++11 features with +std=c++11... no checking whether /opt/gcc-4.7/bin/g++ supports C++11 features with -h std=c++11... no configure: error: *** A compiler with support for C++11 language features is required. Makefile:9451: recipe for target 'configure-gdb' failed make[1]: *** [configure-gdb] Error 1 make[1]: Leaving directory '/home/pedro/brno/pedro/gdb/mygit/cxx-convertion/build-gcc-4.7' If we need to revert back to making C++11 optional, all that's necessary is to change the "mandatory" to "optional" in configure.ac and regenerate configure (both gdb and gdbserver). gdb/ChangeLog: 2016-10-28 Pedro Alves * Makefile.in (CXX_DIALECT): Get from configure. (COMPILE.pre, CC_LD): Append $(CXX_DIALECT). (FLAGS_TO_PASS): Pass CXX_DIALECT. * acinclude.m4: Include ax_cxx_compile_stdcxx.m4. * ax_cxx_compile_stdcxx.m4: Add FSF copyright header. Set and AC_SUBST CXX_DIALECT instead of changing CXX/CXXCPP. * configure.ac: Call AX_CXX_COMPILE_STDCXX. * config.in: Regenerate. * configure: Regenerate. gdb/gdbserver/ChangeLog: 2016-10-28 Pedro Alves * Makefile.in (CXX_DIALECT): Get from configure. (COMPILE.pre, CC_LD): Append $(CXX_DIALECT). * acinclude.m4: Include ../ax_cxx_compile_stdcxx.m4. * configure.ac: Call AX_CXX_COMPILE_STDCXX. * config.in: Regenerate. * configure: Regenerate. --- diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 160f612f672..3376b1b4fc0 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,15 @@ +2016-10-28 Pedro Alves + + * Makefile.in (CXX_DIALECT): Get from configure. + (COMPILE.pre, CC_LD): Append $(CXX_DIALECT). + (FLAGS_TO_PASS): Pass CXX_DIALECT. + * acinclude.m4: Include ax_cxx_compile_stdcxx.m4. + * ax_cxx_compile_stdcxx.m4: Add FSF copyright header. Set and + AC_SUBST CXX_DIALECT instead of changing CXX/CXXCPP. + * configure.ac: Call AX_CXX_COMPILE_STDCXX. + * config.in: Regenerate. + * configure: Regenerate. + 2016-10-28 Pedro Alves * ax_cxx_compile_stdcxx.m4: New file. diff --git a/gdb/Makefile.in b/gdb/Makefile.in index 2c884345eba..d035d8e242a 100644 --- a/gdb/Makefile.in +++ b/gdb/Makefile.in @@ -86,6 +86,7 @@ CATALOGS = @CATALOGS@ # distribution will fix your include files up. CC=@CC@ CXX=@CXX@ +CXX_DIALECT= @CXX_DIALECT@ # Dependency tracking information. DEPMODE = @CCDEPMODE@ @@ -94,7 +95,7 @@ depcomp = $(SHELL) $(srcdir)/../depcomp # Note that these are overridden by GNU make-specific code below if # GNU make is used. The overrides implement dependency tracking. -COMPILE.pre = $(CXX) +COMPILE.pre = $(CXX) $(CXX_DIALECT) COMPILE.post = -c -o $@ COMPILE = $(COMPILE.pre) $(INTERNAL_CFLAGS) $(COMPILE.post) POSTCOMPILE = @true @@ -125,7 +126,7 @@ MAKEHTMLFLAGS = # Set this up with gcc if you have gnu ld and the loader will print out # line numbers for undefined references. #CC_LD=g++ -static -CC_LD=$(CXX) +CC_LD=$(CXX) $(CXX_DIALECT) # Where is our "include" directory? Typically $(srcdir)/../include. # This is essentially the header file directory for the library @@ -742,6 +743,7 @@ FLAGS_TO_PASS = \ "CC=$(CC)" \ "CFLAGS=$(CFLAGS)" \ "CXX=$(CXX)" \ + "CXX_DIALECT=$(CXX_DIALECT)" \ "CXXFLAGS=$(CXXFLAGS)" \ "DLLTOOL=$(DLLTOOL)" \ "LDFLAGS=$(LDFLAGS)" \ diff --git a/gdb/acinclude.m4 b/gdb/acinclude.m4 index 4b3f7fcf95e..daf4a919de2 100644 --- a/gdb/acinclude.m4 +++ b/gdb/acinclude.m4 @@ -68,6 +68,8 @@ m4_include(libiberty.m4) dnl For GDB_AC_PTRACE. m4_include(ptrace.m4) +m4_include(ax_cxx_compile_stdcxx.m4) + ## ----------------------------------------- ## ## ANSIfy the C compiler whenever possible. ## ## From Franc,ois Pinard ## diff --git a/gdb/ax_cxx_compile_stdcxx.m4 b/gdb/ax_cxx_compile_stdcxx.m4 index 2c18e49c56c..ffaeb6e3bbf 100644 --- a/gdb/ax_cxx_compile_stdcxx.m4 +++ b/gdb/ax_cxx_compile_stdcxx.m4 @@ -1,3 +1,12 @@ +# Copyright (c) 2016 Free Software Foundation, Inc. +# +# Originally based on the AX_CXX_COMPILE_STDCXX macro found at the url +# below. +# +# Local GDB customizations: +# +# - AC_SUBST CXX_DIALECT instead of changing CXX/CXXCPP. +# # =========================================================================== # http://www.gnu.org/software/autoconf-archive/ax_cxx_compile_stdcxx.html # =========================================================================== @@ -58,6 +67,7 @@ AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl [$3], [optional], [ax_cxx_compile_cxx$1_required=false], [m4_fatal([invalid third argument `$3' to AX_CXX_COMPILE_STDCXX])]) AC_LANG_PUSH([C++])dnl + CXX_DIALECT="" ac_success=no AC_CACHE_CHECK(whether $CXX supports C++$1 features by default, ax_cv_cxx_compile_cxx$1, @@ -81,10 +91,7 @@ AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl [eval $cachevar=no]) CXX="$ac_save_CXX"]) if eval test x\$$cachevar = xyes; then - CXX="$CXX $switch" - if test -n "$CXXCPP" ; then - CXXCPP="$CXXCPP $switch" - fi + CXX_DIALECT="$switch" ac_success=yes break fi @@ -107,10 +114,7 @@ AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl [eval $cachevar=no]) CXX="$ac_save_CXX"]) if eval test x\$$cachevar = xyes; then - CXX="$CXX $switch" - if test -n "$CXXCPP" ; then - CXXCPP="$CXXCPP $switch" - fi + CXX_DIALECT="$switch" ac_success=yes break fi @@ -131,6 +135,7 @@ AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl [define if the compiler supports basic C++$1 syntax]) fi AC_SUBST(HAVE_CXX$1) + AC_SUBST(CXX_DIALECT) ]) diff --git a/gdb/config.in b/gdb/config.in index 3790d10f9bb..9c841bacb54 100644 --- a/gdb/config.in +++ b/gdb/config.in @@ -84,6 +84,9 @@ /* Define to 1 if you have the header file. */ #undef HAVE_CURSES_H +/* define if the compiler supports basic C++11 syntax */ +#undef HAVE_CXX11 + /* Define to 1 if you have the declaration of `ADDR_NO_RANDOMIZE', and to 0 if you don't. */ #undef HAVE_DECL_ADDR_NO_RANDOMIZE diff --git a/gdb/configure b/gdb/configure index e2d853d05eb..d744f73cd33 100755 --- a/gdb/configure +++ b/gdb/configure @@ -732,6 +732,8 @@ MAKE CCDEPMODE DEPDIR am__leading_dot +CXX_DIALECT +HAVE_CXX11 INSTALL_STRIP_PROGRAM STRIP install_sh @@ -4951,6 +4953,984 @@ ac_script='s/[\\$]/&&/g;s/;s,x,x,$//' program_transform_name=`$as_echo "$program_transform_name" | sed "$ac_script"` +# We require a C++11 compiler. Check if one is available, and if +# necessary, set CXX_DIALECT to some -std=xxx switch. + + ax_cxx_compile_cxx11_required=true + ac_ext=cpp +ac_cpp='$CXXCPP $CPPFLAGS' +ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5' +ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5' +ac_compiler_gnu=$ac_cv_cxx_compiler_gnu + CXX_DIALECT="" + ac_success=no + { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX supports C++11 features by default" >&5 +$as_echo_n "checking whether $CXX supports C++11 features by default... " >&6; } +if test "${ax_cv_cxx_compile_cxx11+set}" = set; then : + $as_echo_n "(cached) " >&6 +else + cat confdefs.h - <<_ACEOF >conftest.$ac_ext +/* end confdefs.h. */ + + +// If the compiler admits that it is not ready for C++11, why torture it? +// Hopefully, this will speed up the test. + +#ifndef __cplusplus + +#error "This is not a C++ compiler" + +#elif __cplusplus < 201103L + +#error "This is not a C++11 compiler" + +#else + +namespace cxx11 +{ + + namespace test_static_assert + { + + template + struct check + { + static_assert(sizeof(int) <= sizeof(T), "not big enough"); + }; + + } + + namespace test_final_override + { + + struct Base + { + virtual void f() {} + }; + + struct Derived : public Base + { + virtual void f() override {} + }; + + } + + namespace test_double_right_angle_brackets + { + + template < typename T > + struct check {}; + + typedef check single_type; + typedef check> double_type; + typedef check>> triple_type; + typedef check>>> quadruple_type; + + } + + namespace test_decltype + { + + int + f() + { + int a = 1; + decltype(a) b = 2; + return a + b; + } + + } + + namespace test_type_deduction + { + + template < typename T1, typename T2 > + struct is_same + { + static const bool value = false; + }; + + template < typename T > + struct is_same + { + static const bool value = true; + }; + + template < typename T1, typename T2 > + auto + add(T1 a1, T2 a2) -> decltype(a1 + a2) + { + return a1 + a2; + } + + int + test(const int c, volatile int v) + { + static_assert(is_same::value == true, ""); + static_assert(is_same::value == false, ""); + static_assert(is_same::value == false, ""); + auto ac = c; + auto av = v; + auto sumi = ac + av + 'x'; + auto sumf = ac + av + 1.0; + static_assert(is_same::value == true, ""); + static_assert(is_same::value == true, ""); + static_assert(is_same::value == true, ""); + static_assert(is_same::value == false, ""); + static_assert(is_same::value == true, ""); + return (sumf > 0.0) ? sumi : add(c, v); + } + + } + + namespace test_noexcept + { + + int f() { return 0; } + int g() noexcept { return 0; } + + static_assert(noexcept(f()) == false, ""); + static_assert(noexcept(g()) == true, ""); + + } + + namespace test_constexpr + { + + template < typename CharT > + unsigned long constexpr + strlen_c_r(const CharT *const s, const unsigned long acc) noexcept + { + return *s ? strlen_c_r(s + 1, acc + 1) : acc; + } + + template < typename CharT > + unsigned long constexpr + strlen_c(const CharT *const s) noexcept + { + return strlen_c_r(s, 0UL); + } + + static_assert(strlen_c("") == 0UL, ""); + static_assert(strlen_c("1") == 1UL, ""); + static_assert(strlen_c("example") == 7UL, ""); + static_assert(strlen_c("another\0example") == 7UL, ""); + + } + + namespace test_rvalue_references + { + + template < int N > + struct answer + { + static constexpr int value = N; + }; + + answer<1> f(int&) { return answer<1>(); } + answer<2> f(const int&) { return answer<2>(); } + answer<3> f(int&&) { return answer<3>(); } + + void + test() + { + int i = 0; + const int c = 0; + static_assert(decltype(f(i))::value == 1, ""); + static_assert(decltype(f(c))::value == 2, ""); + static_assert(decltype(f(0))::value == 3, ""); + } + + } + + namespace test_uniform_initialization + { + + struct test + { + static const int zero {}; + static const int one {1}; + }; + + static_assert(test::zero == 0, ""); + static_assert(test::one == 1, ""); + + } + + namespace test_lambdas + { + + void + test1() + { + auto lambda1 = [](){}; + auto lambda2 = lambda1; + lambda1(); + lambda2(); + } + + int + test2() + { + auto a = [](int i, int j){ return i + j; }(1, 2); + auto b = []() -> int { return '0'; }(); + auto c = [=](){ return a + b; }(); + auto d = [&](){ return c; }(); + auto e = [a, &b](int x) mutable { + const auto identity = [](int y){ return y; }; + for (auto i = 0; i < a; ++i) + a += b--; + return x + identity(a + b); + }(0); + return a + b + c + d + e; + } + + int + test3() + { + const auto nullary = [](){ return 0; }; + const auto unary = [](int x){ return x; }; + using nullary_t = decltype(nullary); + using unary_t = decltype(unary); + const auto higher1st = [](nullary_t f){ return f(); }; + const auto higher2nd = [unary](nullary_t f1){ + return [unary, f1](unary_t f2){ return f2(unary(f1())); }; + }; + return higher1st(nullary) + higher2nd(nullary)(unary); + } + + } + + namespace test_variadic_templates + { + + template + struct sum; + + template + struct sum + { + static constexpr auto value = N0 + sum::value; + }; + + template <> + struct sum<> + { + static constexpr auto value = 0; + }; + + static_assert(sum<>::value == 0, ""); + static_assert(sum<1>::value == 1, ""); + static_assert(sum<23>::value == 23, ""); + static_assert(sum<1, 2>::value == 3, ""); + static_assert(sum<5, 5, 11>::value == 21, ""); + static_assert(sum<2, 3, 5, 7, 11, 13>::value == 41, ""); + + } + + // http://stackoverflow.com/questions/13728184/template-aliases-and-sfinae + // Clang 3.1 fails with headers of libstd++ 4.8.3 when using std::function + // because of this. + namespace test_template_alias_sfinae + { + + struct foo {}; + + template + using member = typename T::member_type; + + template + void func(...) {} + + template + void func(member*) {} + + void test(); + + void test() { func(0); } + + } + +} // namespace cxx11 + +#endif // __cplusplus >= 201103L + + + +_ACEOF +if ac_fn_cxx_try_compile "$LINENO"; then : + ax_cv_cxx_compile_cxx11=yes +else + ax_cv_cxx_compile_cxx11=no +fi +rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext +fi +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ax_cv_cxx_compile_cxx11" >&5 +$as_echo "$ax_cv_cxx_compile_cxx11" >&6; } + if test x$ax_cv_cxx_compile_cxx11 = xyes; then + ac_success=yes + fi + + if test x$ac_success = xno; then + for switch in -std=gnu++11 -std=gnu++0x; do + cachevar=`$as_echo "ax_cv_cxx_compile_cxx11_$switch" | $as_tr_sh` + { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX supports C++11 features with $switch" >&5 +$as_echo_n "checking whether $CXX supports C++11 features with $switch... " >&6; } +if { as_var=$cachevar; eval "test \"\${$as_var+set}\" = set"; }; then : + $as_echo_n "(cached) " >&6 +else + ac_save_CXX="$CXX" + CXX="$CXX $switch" + cat confdefs.h - <<_ACEOF >conftest.$ac_ext +/* end confdefs.h. */ + + +// If the compiler admits that it is not ready for C++11, why torture it? +// Hopefully, this will speed up the test. + +#ifndef __cplusplus + +#error "This is not a C++ compiler" + +#elif __cplusplus < 201103L + +#error "This is not a C++11 compiler" + +#else + +namespace cxx11 +{ + + namespace test_static_assert + { + + template + struct check + { + static_assert(sizeof(int) <= sizeof(T), "not big enough"); + }; + + } + + namespace test_final_override + { + + struct Base + { + virtual void f() {} + }; + + struct Derived : public Base + { + virtual void f() override {} + }; + + } + + namespace test_double_right_angle_brackets + { + + template < typename T > + struct check {}; + + typedef check single_type; + typedef check> double_type; + typedef check>> triple_type; + typedef check>>> quadruple_type; + + } + + namespace test_decltype + { + + int + f() + { + int a = 1; + decltype(a) b = 2; + return a + b; + } + + } + + namespace test_type_deduction + { + + template < typename T1, typename T2 > + struct is_same + { + static const bool value = false; + }; + + template < typename T > + struct is_same + { + static const bool value = true; + }; + + template < typename T1, typename T2 > + auto + add(T1 a1, T2 a2) -> decltype(a1 + a2) + { + return a1 + a2; + } + + int + test(const int c, volatile int v) + { + static_assert(is_same::value == true, ""); + static_assert(is_same::value == false, ""); + static_assert(is_same::value == false, ""); + auto ac = c; + auto av = v; + auto sumi = ac + av + 'x'; + auto sumf = ac + av + 1.0; + static_assert(is_same::value == true, ""); + static_assert(is_same::value == true, ""); + static_assert(is_same::value == true, ""); + static_assert(is_same::value == false, ""); + static_assert(is_same::value == true, ""); + return (sumf > 0.0) ? sumi : add(c, v); + } + + } + + namespace test_noexcept + { + + int f() { return 0; } + int g() noexcept { return 0; } + + static_assert(noexcept(f()) == false, ""); + static_assert(noexcept(g()) == true, ""); + + } + + namespace test_constexpr + { + + template < typename CharT > + unsigned long constexpr + strlen_c_r(const CharT *const s, const unsigned long acc) noexcept + { + return *s ? strlen_c_r(s + 1, acc + 1) : acc; + } + + template < typename CharT > + unsigned long constexpr + strlen_c(const CharT *const s) noexcept + { + return strlen_c_r(s, 0UL); + } + + static_assert(strlen_c("") == 0UL, ""); + static_assert(strlen_c("1") == 1UL, ""); + static_assert(strlen_c("example") == 7UL, ""); + static_assert(strlen_c("another\0example") == 7UL, ""); + + } + + namespace test_rvalue_references + { + + template < int N > + struct answer + { + static constexpr int value = N; + }; + + answer<1> f(int&) { return answer<1>(); } + answer<2> f(const int&) { return answer<2>(); } + answer<3> f(int&&) { return answer<3>(); } + + void + test() + { + int i = 0; + const int c = 0; + static_assert(decltype(f(i))::value == 1, ""); + static_assert(decltype(f(c))::value == 2, ""); + static_assert(decltype(f(0))::value == 3, ""); + } + + } + + namespace test_uniform_initialization + { + + struct test + { + static const int zero {}; + static const int one {1}; + }; + + static_assert(test::zero == 0, ""); + static_assert(test::one == 1, ""); + + } + + namespace test_lambdas + { + + void + test1() + { + auto lambda1 = [](){}; + auto lambda2 = lambda1; + lambda1(); + lambda2(); + } + + int + test2() + { + auto a = [](int i, int j){ return i + j; }(1, 2); + auto b = []() -> int { return '0'; }(); + auto c = [=](){ return a + b; }(); + auto d = [&](){ return c; }(); + auto e = [a, &b](int x) mutable { + const auto identity = [](int y){ return y; }; + for (auto i = 0; i < a; ++i) + a += b--; + return x + identity(a + b); + }(0); + return a + b + c + d + e; + } + + int + test3() + { + const auto nullary = [](){ return 0; }; + const auto unary = [](int x){ return x; }; + using nullary_t = decltype(nullary); + using unary_t = decltype(unary); + const auto higher1st = [](nullary_t f){ return f(); }; + const auto higher2nd = [unary](nullary_t f1){ + return [unary, f1](unary_t f2){ return f2(unary(f1())); }; + }; + return higher1st(nullary) + higher2nd(nullary)(unary); + } + + } + + namespace test_variadic_templates + { + + template + struct sum; + + template + struct sum + { + static constexpr auto value = N0 + sum::value; + }; + + template <> + struct sum<> + { + static constexpr auto value = 0; + }; + + static_assert(sum<>::value == 0, ""); + static_assert(sum<1>::value == 1, ""); + static_assert(sum<23>::value == 23, ""); + static_assert(sum<1, 2>::value == 3, ""); + static_assert(sum<5, 5, 11>::value == 21, ""); + static_assert(sum<2, 3, 5, 7, 11, 13>::value == 41, ""); + + } + + // http://stackoverflow.com/questions/13728184/template-aliases-and-sfinae + // Clang 3.1 fails with headers of libstd++ 4.8.3 when using std::function + // because of this. + namespace test_template_alias_sfinae + { + + struct foo {}; + + template + using member = typename T::member_type; + + template + void func(...) {} + + template + void func(member*) {} + + void test(); + + void test() { func(0); } + + } + +} // namespace cxx11 + +#endif // __cplusplus >= 201103L + + + +_ACEOF +if ac_fn_cxx_try_compile "$LINENO"; then : + eval $cachevar=yes +else + eval $cachevar=no +fi +rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext + CXX="$ac_save_CXX" +fi +eval ac_res=\$$cachevar + { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5 +$as_echo "$ac_res" >&6; } + if eval test x\$$cachevar = xyes; then + CXX_DIALECT="$switch" + ac_success=yes + break + fi + done + fi + + if test x$ac_success = xno; then + for switch in -std=c++11 -std=c++0x +std=c++11 "-h std=c++11"; do + cachevar=`$as_echo "ax_cv_cxx_compile_cxx11_$switch" | $as_tr_sh` + { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX supports C++11 features with $switch" >&5 +$as_echo_n "checking whether $CXX supports C++11 features with $switch... " >&6; } +if { as_var=$cachevar; eval "test \"\${$as_var+set}\" = set"; }; then : + $as_echo_n "(cached) " >&6 +else + ac_save_CXX="$CXX" + CXX="$CXX $switch" + cat confdefs.h - <<_ACEOF >conftest.$ac_ext +/* end confdefs.h. */ + + +// If the compiler admits that it is not ready for C++11, why torture it? +// Hopefully, this will speed up the test. + +#ifndef __cplusplus + +#error "This is not a C++ compiler" + +#elif __cplusplus < 201103L + +#error "This is not a C++11 compiler" + +#else + +namespace cxx11 +{ + + namespace test_static_assert + { + + template + struct check + { + static_assert(sizeof(int) <= sizeof(T), "not big enough"); + }; + + } + + namespace test_final_override + { + + struct Base + { + virtual void f() {} + }; + + struct Derived : public Base + { + virtual void f() override {} + }; + + } + + namespace test_double_right_angle_brackets + { + + template < typename T > + struct check {}; + + typedef check single_type; + typedef check> double_type; + typedef check>> triple_type; + typedef check>>> quadruple_type; + + } + + namespace test_decltype + { + + int + f() + { + int a = 1; + decltype(a) b = 2; + return a + b; + } + + } + + namespace test_type_deduction + { + + template < typename T1, typename T2 > + struct is_same + { + static const bool value = false; + }; + + template < typename T > + struct is_same + { + static const bool value = true; + }; + + template < typename T1, typename T2 > + auto + add(T1 a1, T2 a2) -> decltype(a1 + a2) + { + return a1 + a2; + } + + int + test(const int c, volatile int v) + { + static_assert(is_same::value == true, ""); + static_assert(is_same::value == false, ""); + static_assert(is_same::value == false, ""); + auto ac = c; + auto av = v; + auto sumi = ac + av + 'x'; + auto sumf = ac + av + 1.0; + static_assert(is_same::value == true, ""); + static_assert(is_same::value == true, ""); + static_assert(is_same::value == true, ""); + static_assert(is_same::value == false, ""); + static_assert(is_same::value == true, ""); + return (sumf > 0.0) ? sumi : add(c, v); + } + + } + + namespace test_noexcept + { + + int f() { return 0; } + int g() noexcept { return 0; } + + static_assert(noexcept(f()) == false, ""); + static_assert(noexcept(g()) == true, ""); + + } + + namespace test_constexpr + { + + template < typename CharT > + unsigned long constexpr + strlen_c_r(const CharT *const s, const unsigned long acc) noexcept + { + return *s ? strlen_c_r(s + 1, acc + 1) : acc; + } + + template < typename CharT > + unsigned long constexpr + strlen_c(const CharT *const s) noexcept + { + return strlen_c_r(s, 0UL); + } + + static_assert(strlen_c("") == 0UL, ""); + static_assert(strlen_c("1") == 1UL, ""); + static_assert(strlen_c("example") == 7UL, ""); + static_assert(strlen_c("another\0example") == 7UL, ""); + + } + + namespace test_rvalue_references + { + + template < int N > + struct answer + { + static constexpr int value = N; + }; + + answer<1> f(int&) { return answer<1>(); } + answer<2> f(const int&) { return answer<2>(); } + answer<3> f(int&&) { return answer<3>(); } + + void + test() + { + int i = 0; + const int c = 0; + static_assert(decltype(f(i))::value == 1, ""); + static_assert(decltype(f(c))::value == 2, ""); + static_assert(decltype(f(0))::value == 3, ""); + } + + } + + namespace test_uniform_initialization + { + + struct test + { + static const int zero {}; + static const int one {1}; + }; + + static_assert(test::zero == 0, ""); + static_assert(test::one == 1, ""); + + } + + namespace test_lambdas + { + + void + test1() + { + auto lambda1 = [](){}; + auto lambda2 = lambda1; + lambda1(); + lambda2(); + } + + int + test2() + { + auto a = [](int i, int j){ return i + j; }(1, 2); + auto b = []() -> int { return '0'; }(); + auto c = [=](){ return a + b; }(); + auto d = [&](){ return c; }(); + auto e = [a, &b](int x) mutable { + const auto identity = [](int y){ return y; }; + for (auto i = 0; i < a; ++i) + a += b--; + return x + identity(a + b); + }(0); + return a + b + c + d + e; + } + + int + test3() + { + const auto nullary = [](){ return 0; }; + const auto unary = [](int x){ return x; }; + using nullary_t = decltype(nullary); + using unary_t = decltype(unary); + const auto higher1st = [](nullary_t f){ return f(); }; + const auto higher2nd = [unary](nullary_t f1){ + return [unary, f1](unary_t f2){ return f2(unary(f1())); }; + }; + return higher1st(nullary) + higher2nd(nullary)(unary); + } + + } + + namespace test_variadic_templates + { + + template + struct sum; + + template + struct sum + { + static constexpr auto value = N0 + sum::value; + }; + + template <> + struct sum<> + { + static constexpr auto value = 0; + }; + + static_assert(sum<>::value == 0, ""); + static_assert(sum<1>::value == 1, ""); + static_assert(sum<23>::value == 23, ""); + static_assert(sum<1, 2>::value == 3, ""); + static_assert(sum<5, 5, 11>::value == 21, ""); + static_assert(sum<2, 3, 5, 7, 11, 13>::value == 41, ""); + + } + + // http://stackoverflow.com/questions/13728184/template-aliases-and-sfinae + // Clang 3.1 fails with headers of libstd++ 4.8.3 when using std::function + // because of this. + namespace test_template_alias_sfinae + { + + struct foo {}; + + template + using member = typename T::member_type; + + template + void func(...) {} + + template + void func(member*) {} + + void test(); + + void test() { func(0); } + + } + +} // namespace cxx11 + +#endif // __cplusplus >= 201103L + + + +_ACEOF +if ac_fn_cxx_try_compile "$LINENO"; then : + eval $cachevar=yes +else + eval $cachevar=no +fi +rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext + CXX="$ac_save_CXX" +fi +eval ac_res=\$$cachevar + { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5 +$as_echo "$ac_res" >&6; } + if eval test x\$$cachevar = xyes; then + CXX_DIALECT="$switch" + ac_success=yes + break + fi + done + fi + ac_ext=c +ac_cpp='$CPP $CPPFLAGS' +ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5' +ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5' +ac_compiler_gnu=$ac_cv_c_compiler_gnu + + if test x$ax_cxx_compile_cxx11_required = xtrue; then + if test x$ac_success = xno; then + as_fn_error "*** A compiler with support for C++11 language features is required." "$LINENO" 5 + fi + fi + if test x$ac_success = xno; then + HAVE_CXX11=0 + { $as_echo "$as_me:${as_lineno-$LINENO}: No compiler with C++11 support was found" >&5 +$as_echo "$as_me: No compiler with C++11 support was found" >&6;} + else + HAVE_CXX11=1 + +$as_echo "#define HAVE_CXX11 1" >>confdefs.h + + fi + + + + # Dependency checking. rm -rf .tst 2>/dev/null mkdir .tst 2>/dev/null @@ -14202,7 +15182,6 @@ _ACEOF - # Check whether --enable-werror was given. if test "${enable_werror+set}" = set; then : enableval=$enable_werror; case "${enableval}" in diff --git a/gdb/configure.ac b/gdb/configure.ac index e451e60031c..83c270746e1 100644 --- a/gdb/configure.ac +++ b/gdb/configure.ac @@ -38,6 +38,10 @@ AC_CONFIG_AUX_DIR(..) AC_CANONICAL_SYSTEM AC_ARG_PROGRAM +# We require a C++11 compiler. Check if one is available, and if +# necessary, set CXX_DIALECT to some -std=xxx switch. +AX_CXX_COMPILE_STDCXX(11, , mandatory) + # Dependency checking. ZW_CREATE_DEPDIR ZW_PROG_COMPILER_DEPENDENCIES([CC]) diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog index f65607a966f..2ce767927fd 100644 --- a/gdb/gdbserver/ChangeLog +++ b/gdb/gdbserver/ChangeLog @@ -1,3 +1,12 @@ +2016-10-28 Pedro Alves + + * Makefile.in (CXX_DIALECT): Get from configure. + (COMPILE.pre, CC_LD): Append $(CXX_DIALECT). + * acinclude.m4: Include ../ax_cxx_compile_stdcxx.m4. + * configure.ac: Call AX_CXX_COMPILE_STDCXX. + * config.in: Regenerate. + * configure: Regenerate. + 2016-10-27 Yao Qi * linux-low.c (linux_supports_range_stepping): Return true if diff --git a/gdb/gdbserver/Makefile.in b/gdb/gdbserver/Makefile.in index 0db5287ba91..5ba559cfa53 100644 --- a/gdb/gdbserver/Makefile.in +++ b/gdb/gdbserver/Makefile.in @@ -51,6 +51,7 @@ RANLIB = @RANLIB@ CC = @CC@ CXX = @CXX@ +CXX_DIALECT= @CXX_DIALECT@ AR = @AR@ AR_FLAGS = rc @@ -61,7 +62,7 @@ depcomp = $(SHELL) $(srcdir)/../depcomp # Note that these are overridden by GNU make-specific code below if # GNU make is used. The overrides implement dependency tracking. -COMPILE.pre = $(CXX) +COMPILE.pre = $(CXX) $(CXX_DIALECT) COMPILE.post = -c -o $@ COMPILE = $(COMPILE.pre) $(INTERNAL_CFLAGS) $(COMPILE.post) POSTCOMPILE = @true @@ -80,7 +81,7 @@ VPATH = @srcdir@ # Set this up with gcc if you have gnu ld and the loader will print out # line numbers for undefinded refs. #CC_LD=g++ -static -CC_LD=$(CXX) +CC_LD=$(CXX) $(CXX_DIALECT) # Where is the "include" directory? Traditionally ../include or ./include INCLUDE_DIR = ${srcdir}/../../include diff --git a/gdb/gdbserver/acinclude.m4 b/gdb/gdbserver/acinclude.m4 index 8ec91887cf1..c75d783f57b 100644 --- a/gdb/gdbserver/acinclude.m4 +++ b/gdb/gdbserver/acinclude.m4 @@ -29,6 +29,8 @@ m4_include(../libiberty.m4) dnl For GDB_AC_PTRACE. m4_include(../ptrace.m4) +m4_include(../ax_cxx_compile_stdcxx.m4) + dnl Check for existence of a type $1 in libthread_db.h dnl Based on BFD_HAVE_SYS_PROCFS_TYPE in bfd/bfd.m4. diff --git a/gdb/gdbserver/config.in b/gdb/gdbserver/config.in index 04072cf56b7..b721ea83cf1 100644 --- a/gdb/gdbserver/config.in +++ b/gdb/gdbserver/config.in @@ -18,6 +18,9 @@ /* Define to 1 if you have the header file. */ #undef HAVE_ARPA_INET_H +/* define if the compiler supports basic C++11 syntax */ +#undef HAVE_CXX11 + /* Define to 1 if you have the declaration of `ADDR_NO_RANDOMIZE', and to 0 if you don't. */ #undef HAVE_DECL_ADDR_NO_RANDOMIZE diff --git a/gdb/gdbserver/configure b/gdb/gdbserver/configure index f1125173740..bbce742eeb9 100755 --- a/gdb/gdbserver/configure +++ b/gdb/gdbserver/configure @@ -615,6 +615,8 @@ DEPDIR am__leading_dot host_noncanonical target_noncanonical +CXX_DIALECT +HAVE_CXX11 RANLIB AR INSTALL_DATA @@ -4656,6 +4658,984 @@ ac_script='s/[\\$]/&&/g;s/;s,x,x,$//' program_transform_name=`$as_echo "$program_transform_name" | sed "$ac_script"` +# We require a C++11 compiler. Check if one is available, and if +# necessary, set CXX_DIALECT to some -std=xxx switch. + + ax_cxx_compile_cxx11_required=true + ac_ext=cpp +ac_cpp='$CXXCPP $CPPFLAGS' +ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5' +ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5' +ac_compiler_gnu=$ac_cv_cxx_compiler_gnu + CXX_DIALECT="" + ac_success=no + { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX supports C++11 features by default" >&5 +$as_echo_n "checking whether $CXX supports C++11 features by default... " >&6; } +if test "${ax_cv_cxx_compile_cxx11+set}" = set; then : + $as_echo_n "(cached) " >&6 +else + cat confdefs.h - <<_ACEOF >conftest.$ac_ext +/* end confdefs.h. */ + + +// If the compiler admits that it is not ready for C++11, why torture it? +// Hopefully, this will speed up the test. + +#ifndef __cplusplus + +#error "This is not a C++ compiler" + +#elif __cplusplus < 201103L + +#error "This is not a C++11 compiler" + +#else + +namespace cxx11 +{ + + namespace test_static_assert + { + + template + struct check + { + static_assert(sizeof(int) <= sizeof(T), "not big enough"); + }; + + } + + namespace test_final_override + { + + struct Base + { + virtual void f() {} + }; + + struct Derived : public Base + { + virtual void f() override {} + }; + + } + + namespace test_double_right_angle_brackets + { + + template < typename T > + struct check {}; + + typedef check single_type; + typedef check> double_type; + typedef check>> triple_type; + typedef check>>> quadruple_type; + + } + + namespace test_decltype + { + + int + f() + { + int a = 1; + decltype(a) b = 2; + return a + b; + } + + } + + namespace test_type_deduction + { + + template < typename T1, typename T2 > + struct is_same + { + static const bool value = false; + }; + + template < typename T > + struct is_same + { + static const bool value = true; + }; + + template < typename T1, typename T2 > + auto + add(T1 a1, T2 a2) -> decltype(a1 + a2) + { + return a1 + a2; + } + + int + test(const int c, volatile int v) + { + static_assert(is_same::value == true, ""); + static_assert(is_same::value == false, ""); + static_assert(is_same::value == false, ""); + auto ac = c; + auto av = v; + auto sumi = ac + av + 'x'; + auto sumf = ac + av + 1.0; + static_assert(is_same::value == true, ""); + static_assert(is_same::value == true, ""); + static_assert(is_same::value == true, ""); + static_assert(is_same::value == false, ""); + static_assert(is_same::value == true, ""); + return (sumf > 0.0) ? sumi : add(c, v); + } + + } + + namespace test_noexcept + { + + int f() { return 0; } + int g() noexcept { return 0; } + + static_assert(noexcept(f()) == false, ""); + static_assert(noexcept(g()) == true, ""); + + } + + namespace test_constexpr + { + + template < typename CharT > + unsigned long constexpr + strlen_c_r(const CharT *const s, const unsigned long acc) noexcept + { + return *s ? strlen_c_r(s + 1, acc + 1) : acc; + } + + template < typename CharT > + unsigned long constexpr + strlen_c(const CharT *const s) noexcept + { + return strlen_c_r(s, 0UL); + } + + static_assert(strlen_c("") == 0UL, ""); + static_assert(strlen_c("1") == 1UL, ""); + static_assert(strlen_c("example") == 7UL, ""); + static_assert(strlen_c("another\0example") == 7UL, ""); + + } + + namespace test_rvalue_references + { + + template < int N > + struct answer + { + static constexpr int value = N; + }; + + answer<1> f(int&) { return answer<1>(); } + answer<2> f(const int&) { return answer<2>(); } + answer<3> f(int&&) { return answer<3>(); } + + void + test() + { + int i = 0; + const int c = 0; + static_assert(decltype(f(i))::value == 1, ""); + static_assert(decltype(f(c))::value == 2, ""); + static_assert(decltype(f(0))::value == 3, ""); + } + + } + + namespace test_uniform_initialization + { + + struct test + { + static const int zero {}; + static const int one {1}; + }; + + static_assert(test::zero == 0, ""); + static_assert(test::one == 1, ""); + + } + + namespace test_lambdas + { + + void + test1() + { + auto lambda1 = [](){}; + auto lambda2 = lambda1; + lambda1(); + lambda2(); + } + + int + test2() + { + auto a = [](int i, int j){ return i + j; }(1, 2); + auto b = []() -> int { return '0'; }(); + auto c = [=](){ return a + b; }(); + auto d = [&](){ return c; }(); + auto e = [a, &b](int x) mutable { + const auto identity = [](int y){ return y; }; + for (auto i = 0; i < a; ++i) + a += b--; + return x + identity(a + b); + }(0); + return a + b + c + d + e; + } + + int + test3() + { + const auto nullary = [](){ return 0; }; + const auto unary = [](int x){ return x; }; + using nullary_t = decltype(nullary); + using unary_t = decltype(unary); + const auto higher1st = [](nullary_t f){ return f(); }; + const auto higher2nd = [unary](nullary_t f1){ + return [unary, f1](unary_t f2){ return f2(unary(f1())); }; + }; + return higher1st(nullary) + higher2nd(nullary)(unary); + } + + } + + namespace test_variadic_templates + { + + template + struct sum; + + template + struct sum + { + static constexpr auto value = N0 + sum::value; + }; + + template <> + struct sum<> + { + static constexpr auto value = 0; + }; + + static_assert(sum<>::value == 0, ""); + static_assert(sum<1>::value == 1, ""); + static_assert(sum<23>::value == 23, ""); + static_assert(sum<1, 2>::value == 3, ""); + static_assert(sum<5, 5, 11>::value == 21, ""); + static_assert(sum<2, 3, 5, 7, 11, 13>::value == 41, ""); + + } + + // http://stackoverflow.com/questions/13728184/template-aliases-and-sfinae + // Clang 3.1 fails with headers of libstd++ 4.8.3 when using std::function + // because of this. + namespace test_template_alias_sfinae + { + + struct foo {}; + + template + using member = typename T::member_type; + + template + void func(...) {} + + template + void func(member*) {} + + void test(); + + void test() { func(0); } + + } + +} // namespace cxx11 + +#endif // __cplusplus >= 201103L + + + +_ACEOF +if ac_fn_cxx_try_compile "$LINENO"; then : + ax_cv_cxx_compile_cxx11=yes +else + ax_cv_cxx_compile_cxx11=no +fi +rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext +fi +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ax_cv_cxx_compile_cxx11" >&5 +$as_echo "$ax_cv_cxx_compile_cxx11" >&6; } + if test x$ax_cv_cxx_compile_cxx11 = xyes; then + ac_success=yes + fi + + if test x$ac_success = xno; then + for switch in -std=gnu++11 -std=gnu++0x; do + cachevar=`$as_echo "ax_cv_cxx_compile_cxx11_$switch" | $as_tr_sh` + { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX supports C++11 features with $switch" >&5 +$as_echo_n "checking whether $CXX supports C++11 features with $switch... " >&6; } +if { as_var=$cachevar; eval "test \"\${$as_var+set}\" = set"; }; then : + $as_echo_n "(cached) " >&6 +else + ac_save_CXX="$CXX" + CXX="$CXX $switch" + cat confdefs.h - <<_ACEOF >conftest.$ac_ext +/* end confdefs.h. */ + + +// If the compiler admits that it is not ready for C++11, why torture it? +// Hopefully, this will speed up the test. + +#ifndef __cplusplus + +#error "This is not a C++ compiler" + +#elif __cplusplus < 201103L + +#error "This is not a C++11 compiler" + +#else + +namespace cxx11 +{ + + namespace test_static_assert + { + + template + struct check + { + static_assert(sizeof(int) <= sizeof(T), "not big enough"); + }; + + } + + namespace test_final_override + { + + struct Base + { + virtual void f() {} + }; + + struct Derived : public Base + { + virtual void f() override {} + }; + + } + + namespace test_double_right_angle_brackets + { + + template < typename T > + struct check {}; + + typedef check single_type; + typedef check> double_type; + typedef check>> triple_type; + typedef check>>> quadruple_type; + + } + + namespace test_decltype + { + + int + f() + { + int a = 1; + decltype(a) b = 2; + return a + b; + } + + } + + namespace test_type_deduction + { + + template < typename T1, typename T2 > + struct is_same + { + static const bool value = false; + }; + + template < typename T > + struct is_same + { + static const bool value = true; + }; + + template < typename T1, typename T2 > + auto + add(T1 a1, T2 a2) -> decltype(a1 + a2) + { + return a1 + a2; + } + + int + test(const int c, volatile int v) + { + static_assert(is_same::value == true, ""); + static_assert(is_same::value == false, ""); + static_assert(is_same::value == false, ""); + auto ac = c; + auto av = v; + auto sumi = ac + av + 'x'; + auto sumf = ac + av + 1.0; + static_assert(is_same::value == true, ""); + static_assert(is_same::value == true, ""); + static_assert(is_same::value == true, ""); + static_assert(is_same::value == false, ""); + static_assert(is_same::value == true, ""); + return (sumf > 0.0) ? sumi : add(c, v); + } + + } + + namespace test_noexcept + { + + int f() { return 0; } + int g() noexcept { return 0; } + + static_assert(noexcept(f()) == false, ""); + static_assert(noexcept(g()) == true, ""); + + } + + namespace test_constexpr + { + + template < typename CharT > + unsigned long constexpr + strlen_c_r(const CharT *const s, const unsigned long acc) noexcept + { + return *s ? strlen_c_r(s + 1, acc + 1) : acc; + } + + template < typename CharT > + unsigned long constexpr + strlen_c(const CharT *const s) noexcept + { + return strlen_c_r(s, 0UL); + } + + static_assert(strlen_c("") == 0UL, ""); + static_assert(strlen_c("1") == 1UL, ""); + static_assert(strlen_c("example") == 7UL, ""); + static_assert(strlen_c("another\0example") == 7UL, ""); + + } + + namespace test_rvalue_references + { + + template < int N > + struct answer + { + static constexpr int value = N; + }; + + answer<1> f(int&) { return answer<1>(); } + answer<2> f(const int&) { return answer<2>(); } + answer<3> f(int&&) { return answer<3>(); } + + void + test() + { + int i = 0; + const int c = 0; + static_assert(decltype(f(i))::value == 1, ""); + static_assert(decltype(f(c))::value == 2, ""); + static_assert(decltype(f(0))::value == 3, ""); + } + + } + + namespace test_uniform_initialization + { + + struct test + { + static const int zero {}; + static const int one {1}; + }; + + static_assert(test::zero == 0, ""); + static_assert(test::one == 1, ""); + + } + + namespace test_lambdas + { + + void + test1() + { + auto lambda1 = [](){}; + auto lambda2 = lambda1; + lambda1(); + lambda2(); + } + + int + test2() + { + auto a = [](int i, int j){ return i + j; }(1, 2); + auto b = []() -> int { return '0'; }(); + auto c = [=](){ return a + b; }(); + auto d = [&](){ return c; }(); + auto e = [a, &b](int x) mutable { + const auto identity = [](int y){ return y; }; + for (auto i = 0; i < a; ++i) + a += b--; + return x + identity(a + b); + }(0); + return a + b + c + d + e; + } + + int + test3() + { + const auto nullary = [](){ return 0; }; + const auto unary = [](int x){ return x; }; + using nullary_t = decltype(nullary); + using unary_t = decltype(unary); + const auto higher1st = [](nullary_t f){ return f(); }; + const auto higher2nd = [unary](nullary_t f1){ + return [unary, f1](unary_t f2){ return f2(unary(f1())); }; + }; + return higher1st(nullary) + higher2nd(nullary)(unary); + } + + } + + namespace test_variadic_templates + { + + template + struct sum; + + template + struct sum + { + static constexpr auto value = N0 + sum::value; + }; + + template <> + struct sum<> + { + static constexpr auto value = 0; + }; + + static_assert(sum<>::value == 0, ""); + static_assert(sum<1>::value == 1, ""); + static_assert(sum<23>::value == 23, ""); + static_assert(sum<1, 2>::value == 3, ""); + static_assert(sum<5, 5, 11>::value == 21, ""); + static_assert(sum<2, 3, 5, 7, 11, 13>::value == 41, ""); + + } + + // http://stackoverflow.com/questions/13728184/template-aliases-and-sfinae + // Clang 3.1 fails with headers of libstd++ 4.8.3 when using std::function + // because of this. + namespace test_template_alias_sfinae + { + + struct foo {}; + + template + using member = typename T::member_type; + + template + void func(...) {} + + template + void func(member*) {} + + void test(); + + void test() { func(0); } + + } + +} // namespace cxx11 + +#endif // __cplusplus >= 201103L + + + +_ACEOF +if ac_fn_cxx_try_compile "$LINENO"; then : + eval $cachevar=yes +else + eval $cachevar=no +fi +rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext + CXX="$ac_save_CXX" +fi +eval ac_res=\$$cachevar + { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5 +$as_echo "$ac_res" >&6; } + if eval test x\$$cachevar = xyes; then + CXX_DIALECT="$switch" + ac_success=yes + break + fi + done + fi + + if test x$ac_success = xno; then + for switch in -std=c++11 -std=c++0x +std=c++11 "-h std=c++11"; do + cachevar=`$as_echo "ax_cv_cxx_compile_cxx11_$switch" | $as_tr_sh` + { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX supports C++11 features with $switch" >&5 +$as_echo_n "checking whether $CXX supports C++11 features with $switch... " >&6; } +if { as_var=$cachevar; eval "test \"\${$as_var+set}\" = set"; }; then : + $as_echo_n "(cached) " >&6 +else + ac_save_CXX="$CXX" + CXX="$CXX $switch" + cat confdefs.h - <<_ACEOF >conftest.$ac_ext +/* end confdefs.h. */ + + +// If the compiler admits that it is not ready for C++11, why torture it? +// Hopefully, this will speed up the test. + +#ifndef __cplusplus + +#error "This is not a C++ compiler" + +#elif __cplusplus < 201103L + +#error "This is not a C++11 compiler" + +#else + +namespace cxx11 +{ + + namespace test_static_assert + { + + template + struct check + { + static_assert(sizeof(int) <= sizeof(T), "not big enough"); + }; + + } + + namespace test_final_override + { + + struct Base + { + virtual void f() {} + }; + + struct Derived : public Base + { + virtual void f() override {} + }; + + } + + namespace test_double_right_angle_brackets + { + + template < typename T > + struct check {}; + + typedef check single_type; + typedef check> double_type; + typedef check>> triple_type; + typedef check>>> quadruple_type; + + } + + namespace test_decltype + { + + int + f() + { + int a = 1; + decltype(a) b = 2; + return a + b; + } + + } + + namespace test_type_deduction + { + + template < typename T1, typename T2 > + struct is_same + { + static const bool value = false; + }; + + template < typename T > + struct is_same + { + static const bool value = true; + }; + + template < typename T1, typename T2 > + auto + add(T1 a1, T2 a2) -> decltype(a1 + a2) + { + return a1 + a2; + } + + int + test(const int c, volatile int v) + { + static_assert(is_same::value == true, ""); + static_assert(is_same::value == false, ""); + static_assert(is_same::value == false, ""); + auto ac = c; + auto av = v; + auto sumi = ac + av + 'x'; + auto sumf = ac + av + 1.0; + static_assert(is_same::value == true, ""); + static_assert(is_same::value == true, ""); + static_assert(is_same::value == true, ""); + static_assert(is_same::value == false, ""); + static_assert(is_same::value == true, ""); + return (sumf > 0.0) ? sumi : add(c, v); + } + + } + + namespace test_noexcept + { + + int f() { return 0; } + int g() noexcept { return 0; } + + static_assert(noexcept(f()) == false, ""); + static_assert(noexcept(g()) == true, ""); + + } + + namespace test_constexpr + { + + template < typename CharT > + unsigned long constexpr + strlen_c_r(const CharT *const s, const unsigned long acc) noexcept + { + return *s ? strlen_c_r(s + 1, acc + 1) : acc; + } + + template < typename CharT > + unsigned long constexpr + strlen_c(const CharT *const s) noexcept + { + return strlen_c_r(s, 0UL); + } + + static_assert(strlen_c("") == 0UL, ""); + static_assert(strlen_c("1") == 1UL, ""); + static_assert(strlen_c("example") == 7UL, ""); + static_assert(strlen_c("another\0example") == 7UL, ""); + + } + + namespace test_rvalue_references + { + + template < int N > + struct answer + { + static constexpr int value = N; + }; + + answer<1> f(int&) { return answer<1>(); } + answer<2> f(const int&) { return answer<2>(); } + answer<3> f(int&&) { return answer<3>(); } + + void + test() + { + int i = 0; + const int c = 0; + static_assert(decltype(f(i))::value == 1, ""); + static_assert(decltype(f(c))::value == 2, ""); + static_assert(decltype(f(0))::value == 3, ""); + } + + } + + namespace test_uniform_initialization + { + + struct test + { + static const int zero {}; + static const int one {1}; + }; + + static_assert(test::zero == 0, ""); + static_assert(test::one == 1, ""); + + } + + namespace test_lambdas + { + + void + test1() + { + auto lambda1 = [](){}; + auto lambda2 = lambda1; + lambda1(); + lambda2(); + } + + int + test2() + { + auto a = [](int i, int j){ return i + j; }(1, 2); + auto b = []() -> int { return '0'; }(); + auto c = [=](){ return a + b; }(); + auto d = [&](){ return c; }(); + auto e = [a, &b](int x) mutable { + const auto identity = [](int y){ return y; }; + for (auto i = 0; i < a; ++i) + a += b--; + return x + identity(a + b); + }(0); + return a + b + c + d + e; + } + + int + test3() + { + const auto nullary = [](){ return 0; }; + const auto unary = [](int x){ return x; }; + using nullary_t = decltype(nullary); + using unary_t = decltype(unary); + const auto higher1st = [](nullary_t f){ return f(); }; + const auto higher2nd = [unary](nullary_t f1){ + return [unary, f1](unary_t f2){ return f2(unary(f1())); }; + }; + return higher1st(nullary) + higher2nd(nullary)(unary); + } + + } + + namespace test_variadic_templates + { + + template + struct sum; + + template + struct sum + { + static constexpr auto value = N0 + sum::value; + }; + + template <> + struct sum<> + { + static constexpr auto value = 0; + }; + + static_assert(sum<>::value == 0, ""); + static_assert(sum<1>::value == 1, ""); + static_assert(sum<23>::value == 23, ""); + static_assert(sum<1, 2>::value == 3, ""); + static_assert(sum<5, 5, 11>::value == 21, ""); + static_assert(sum<2, 3, 5, 7, 11, 13>::value == 41, ""); + + } + + // http://stackoverflow.com/questions/13728184/template-aliases-and-sfinae + // Clang 3.1 fails with headers of libstd++ 4.8.3 when using std::function + // because of this. + namespace test_template_alias_sfinae + { + + struct foo {}; + + template + using member = typename T::member_type; + + template + void func(...) {} + + template + void func(member*) {} + + void test(); + + void test() { func(0); } + + } + +} // namespace cxx11 + +#endif // __cplusplus >= 201103L + + + +_ACEOF +if ac_fn_cxx_try_compile "$LINENO"; then : + eval $cachevar=yes +else + eval $cachevar=no +fi +rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext + CXX="$ac_save_CXX" +fi +eval ac_res=\$$cachevar + { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5 +$as_echo "$ac_res" >&6; } + if eval test x\$$cachevar = xyes; then + CXX_DIALECT="$switch" + ac_success=yes + break + fi + done + fi + ac_ext=c +ac_cpp='$CPP $CPPFLAGS' +ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5' +ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5' +ac_compiler_gnu=$ac_cv_c_compiler_gnu + + if test x$ax_cxx_compile_cxx11_required = xtrue; then + if test x$ac_success = xno; then + as_fn_error "*** A compiler with support for C++11 language features is required." "$LINENO" 5 + fi + fi + if test x$ac_success = xno; then + HAVE_CXX11=0 + { $as_echo "$as_me:${as_lineno-$LINENO}: No compiler with C++11 support was found" >&5 +$as_echo "$as_me: No compiler with C++11 support was found" >&6;} + else + HAVE_CXX11=1 + +$as_echo "#define HAVE_CXX11 1" >>confdefs.h + + fi + + + + { $as_echo "$as_me:${as_lineno-$LINENO}: checking for ANSI C header files" >&5 $as_echo_n "checking for ANSI C header files... " >&6; } if test "${ac_cv_header_stdc+set}" = set; then : @@ -6236,7 +7216,6 @@ fi - # Check whether --enable-werror was given. if test "${enable_werror+set}" = set; then : enableval=$enable_werror; case "${enableval}" in diff --git a/gdb/gdbserver/configure.ac b/gdb/gdbserver/configure.ac index 6d5907bfaae..11d8c79cdcf 100644 --- a/gdb/gdbserver/configure.ac +++ b/gdb/gdbserver/configure.ac @@ -38,6 +38,10 @@ AC_PROG_RANLIB AC_ARG_PROGRAM +# We require a C++11 compiler. Check if one is available, and if +# necessary, set CXX_DIALECT to some -std=xxx switch. +AX_CXX_COMPILE_STDCXX(11, , mandatory) + AC_HEADER_STDC # Set the 'development' global.