DragonFlyBSD

Pierre,

I don't have a fix but here's why.

In contrib/gcc-4.7/libstdc++-v3/include/bits/basic_string.h we find:

---------
#if (defined(GXX_EXPERIMENTAL_CXX0X) && defined(_GLIBCXX_USE_C99) \
&& !defined(_GLIBCXX_HAVE_BROKEN_VSWPRINTF))

#include <ext/string_conversions.h>

namespace std _GLIBCXX_VISIBILITY(default) {
_GLIBCXX_BEGIN_NAMESPACE_VERSION

// 21.4 Numeric Conversions [string.conversions].
  inline int
  stoi(const string& __str, size_t* __idx = 0, int __base = 10)
{ return _gnu_cxx::_stoa<long, int>(&std::strtol, "stoi", __str.c_str(),
                                        __idx, __base); }
  ...

_GLIBCXX_END_NAMESPACE_VERSION
} // namespace

#endif /* GXX_EXPERIMENTAL_CXX0X && _GLIBCXX_USE_C99 ... */
---------

GXX_EXPERIMENTAL_CXX0X is defined, _GLIBCXX_HAVE_BROKEN_VSWPRINTF isn't, so we're clear regarding those two. However, _GLIBCXX_USE_C99 isn't defined, but it's needed for stoi() and various other functions.

From libstdc++-v3's configure output:

checking for ISO C99 support in <complex.h>... no
checking for ISO C99 support in <stdio.h>... yes
checking for ISO C99 support in <stdlib.h>... yes
checking for ISO C99 support in <wchar.h>... yes
checking for fully enabled ISO C99 support... no

Compiling the associated conftest for complex.h gives this:

complex.c:(.text+0x19b): undefined reference to `clogf'
complex.c:(.text+0x3e6): undefined reference to `cpowf'
complex.c:(.text+0x65d): undefined reference to `clog'
complex.c:(.text+0x8db): undefined reference to `cpow'
complex.c:(.text+0xa0c): undefined reference to `ccosl'
complex.c:(.text+0xa7c): undefined reference to `ccoshl'
complex.c:(.text+0xaec): undefined reference to `cexpl'
complex.c:(.text+0xb5c): undefined reference to `clogl'
complex.c:(.text+0xbcc): undefined reference to `csinl'
complex.c:(.text+0xc3c): undefined reference to `csinhl'
complex.c:(.text+0xd1c): undefined reference to `ctanl'
complex.c:(.text+0xd8c): undefined reference to `ctanhl'
complex.c:(.text+0xe2a): undefined reference to `cpowl'

So it seems we need these functions first before we could enable _GLIBCXX_USE_C99 which would then cause stoi() to be present.

Regards,
Sascha

And in fact, using

g++ -D_GLIBCXX_USE_C99 --std=c++11 -o stoitest stoitest.cpp

it will compile.

gcc has the missing functions built in, although I don't know yet if this includes gcc 4.7. A failed conftest doesn't mean there's no C99, it just means it needs to use builtin intead of libc I think.

https://gcc.gnu.org/onlinedocs/gcc-4.7.4/gcc/Other-Builtins.html

The ISO C99 functions _Exit, acoshf, acoshl, acosh, asinhf, asinhl, asinh, atanhf, atanhl, atanh, cabsf, cabsl, cabs, cacosf, cacoshf, cacoshl, cacosh, cacosl, cacos, cargf, cargl, carg, casinf, casinhf, casinhl, casinh, casinl, casin, catanf, catanhf, catanhl, catanh, catanl, catan, cbrtf, cbrtl, cbrt, ccosf, ccoshf, ccoshl, ccosh, ccosl, ccos, cexpf, cexpl, cexp, cimagf, cimagl, cimag, clogf, clogl, clog, conjf, conjl, conj, copysignf, copysignl, copysign, cpowf, cpowl, cpow, cprojf, cprojl, cproj, crealf, creall, creal, csinf, csinhf, csinhl, csinh, csinl, csin, csqrtf, csqrtl, csqrt, ctanf, ctanhf, ctanhl, ctanh, ctanl, ctan, erfcf, erfcl, erfc, erff, erfl, erf, exp2f, exp2l, exp2, expm1f, expm1l, expm1, fdimf, fdiml, fdim, fmaf, fmal, fmaxf, fmaxl, fmax, fma, fminf, fminl, fmin, hypotf, hypotl, hypot, ilogbf, ilogbl, ilogb, imaxabs, isblank, iswblank, lgammaf, lgammal, lgamma, llabs, llrintf, llrintl, llrint, llroundf, llroundl, llround, log1pf, log1pl, log1p, log2f, log2l, log2, logbf, logbl, logb, lrintf, lrintl, lrint, lroundf, lroundl, lround, nearbyintf, nearbyintl, nearbyint, nextafterf, nextafterl, nextafter, nexttowardf, nexttowardl, nexttoward, remainderf, remainderl, remainder, remquof, remquol, remquo, rintf, rintl, rint, roundf, roundl, round, scalblnf, scalblnl, scalbln, scalbnf, scalbnl, scalbn, snprintf, tgammaf, tgammal, tgamma, truncf, truncl, trunc, vfscanf, vscanf, vsnprintf and vsscanf are handled as built-in functions except in strict ISO C90 mode (-ansi or -std=c90).

early research of mine indicates swildner is correct and the missing obscure complex functions are causing dragonfly to be declared C99 incapable even though it could handle stoi and other functions.

Maybe it's best just to add the functions from NetBSD into libm.