FreeBSD: make buildworld failure in libllvmsupport

Saya mendapat error yg cukup mengesalkan ketika Rebuild FreeBSD dari source , cukup lama googling mencari referensi error yang terjadi, ternyata solusinya cukup simple meskipun dengan nebak2 library clang(1) yg digunakan. Seperti kita ketahui bahwa FreeBSD 10.0-RELEASE sudah merubah untuk default compilernya dari GCC ke clang(1). Berikut saya post error yang terjadi:

c++  -O2 -pipe -I/usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/include -I/usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/tools/clang/include -I/usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/lib/Support -I. -I/usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/../../lib/clang/include -DLLVM_ON_UNIX -DLLVM_ON_FREEBSD -D__STDC_LIMIT_MACROS -D__STDC_CONSTANT_MACROS -DNDEBUG -fno-strict-aliasing -DLLVM_DEFAULT_TARGET_TRIPLE=\"i386-unknown-freebsd10.3\" -DLLVM_HOST_TRIPLE=\"i386-unknown-freebsd10.3\" -DDEFAULT_SYSROOT=\"\" -ffunction-sections -fdata-sections -I/usr/obj/usr/src/tmp/legacy/usr/include  -fno-exceptions -fno-rtti  -c /usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/lib/Support/APFloat.cpp -o APFloat.o
In file included from /usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/lib/Support/APFloat.cpp:15:
In file included from /usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/include/llvm/ADT/APFloat.h:20:
In file included from /usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/include/llvm/ADT/APInt.h:19:
In file included from /usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/include/llvm/ADT/ArrayRef.h:14:
In file included from /usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/include/llvm/ADT/SmallVector.h:17:
In file included from /usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/include/llvm/Support/AlignOf.h:19:
In file included from /usr/include/c++/v1/cstddef:38:
In file included from /usr/include/c++/v1/stddef.h:51:
/usr/include/c++/v1/__nullptr:24:29: error: variable has incomplete type 'struct _LIBCPP_TEMPLATE_VIS'
struct _LIBCPP_TEMPLATE_VIS nullptr_t
                            ^
/usr/include/c++/v1/__nullptr:24:8: note: forward declaration of 'std::__1::_LIBCPP_TEMPLATE_VIS'
struct _LIBCPP_TEMPLATE_VIS nullptr_t
       ^
/usr/include/c++/v1/__nullptr:24:38: error: expected ';' after top level declarator
struct _LIBCPP_TEMPLATE_VIS nullptr_t
                                     ^
/usr/include/c++/v1/__nullptr:47:48: error: unknown type name 'nullptr_t'
inline _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR nullptr_t __get_nullptr_t() {return nullptr_t(0);}
                                               ^
In file included from /usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/lib/Support/APFloat.cpp:15:
In file included from /usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/include/llvm/ADT/APFloat.h:20:
In file included from /usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/include/llvm/ADT/APInt.h:19:
In file included from /usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/include/llvm/ADT/ArrayRef.h:14:
In file included from /usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/include/llvm/ADT/SmallVector.h:19:
In file included from /usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/include/llvm/Support/MathExtras.h:18:
In file included from /usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/include/llvm/Support/SwapByteOrder.h:18:
In file included from /usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/../../lib/clang/include/llvm/Support/DataTypes.h:36:
In file included from /usr/include/c++/v1/cmath:301:
In file included from /usr/include/c++/v1/math.h:309:
/usr/include/c++/v1/type_traits:472:114: error: expected class name
    : public integral_constant(nullptr)) == 1> {};
                                                                                                                 ^
In file included from /usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/lib/Support/APFloat.cpp:15:
In file included from /usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/include/llvm/ADT/APFloat.h:20:
In file included from /usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/include/llvm/ADT/APInt.h:19:
In file included from /usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/include/llvm/ADT/ArrayRef.h:14:
In file included from /usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/include/llvm/ADT/SmallVector.h:19:
In file included from /usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/include/llvm/Support/MathExtras.h:18:
In file included from /usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/include/llvm/Support/SwapByteOrder.h:18:
In file included from /usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/../../lib/clang/include/llvm/Support/DataTypes.h:36:
/usr/include/c++/v1/cmath:679:46: error: declaration conflicts with target of using declaration already in scope
inline _LIBCPP_INLINE_VISIBILITY float       acos(float __lcpp_x) _NOEXCEPT       {return acosf(__lcpp_x);}
                                             ^
/usr/include/c++/v1/math.h:654:46: note: target of using declaration
inline _LIBCPP_INLINE_VISIBILITY float       acos(float __lcpp_x) _NOEXCEPT       {return acosf(__lcpp_x);}
                                             ^
/usr/include/c++/v1/cmath:675:9: note: using declaration
using ::acos;
        ^
/usr/include/c++/v1/cmath:680:46: error: declaration conflicts with target of using declaration already in scope
inline _LIBCPP_INLINE_VISIBILITY long double acos(long double __lcpp_x) _NOEXCEPT {return acosl(__lcpp_x);}
                                             ^
/usr/include/c++/v1/math.h:655:46: note: target of using declaration
inline _LIBCPP_INLINE_VISIBILITY long double acos(long double __lcpp_x) _NOEXCEPT {return acosl(__lcpp_x);}
                                             ^
/usr/include/c++/v1/cmath:675:9: note: using declaration
using ::acos;
        ^
/usr/include/c++/v1/cmath:686:1: error: declaration conflicts with target of using declaration already in scope
acos(_A1 __lcpp_x) _NOEXCEPT {return acos((double)__lcpp_x);}
^
/usr/include/c++/v1/math.h:661:1: note: target of using declaration
acos(_A1 __lcpp_x) _NOEXCEPT {return acos((double)__lcpp_x);}
^
/usr/include/c++/v1/cmath:675:9: note: using declaration
using ::acos;
        ^
/usr/include/c++/v1/cmath:694:46: error: declaration conflicts with target of using declaration already in scope
inline _LIBCPP_INLINE_VISIBILITY float       asin(float __lcpp_x) _NOEXCEPT       {return asinf(__lcpp_x);}
                                             ^
/usr/include/c++/v1/math.h:666:46: note: target of using declaration
inline _LIBCPP_INLINE_VISIBILITY float       asin(float __lcpp_x) _NOEXCEPT       {return asinf(__lcpp_x);}
                                             ^
/usr/include/c++/v1/cmath:690:9: note: using declaration
using ::asin;
        ^
/usr/include/c++/v1/cmath:695:46: error: declaration conflicts with target of using declaration already in scope
inline _LIBCPP_INLINE_VISIBILITY long double asin(long double __lcpp_x) _NOEXCEPT {return asinl(__lcpp_x);}
                                             ^
/usr/include/c++/v1/math.h:667:46: note: target of using declaration
inline _LIBCPP_INLINE_VISIBILITY long double asin(long double __lcpp_x) _NOEXCEPT {return asinl(__lcpp_x);}
                                             ^
/usr/include/c++/v1/cmath:690:9: note: using declaration
using ::asin;
        ^
/usr/include/c++/v1/cmath:701:1: error: declaration conflicts with target of using declaration already in scope
asin(_A1 __lcpp_x) _NOEXCEPT {return asin((double)__lcpp_x);}
^
/usr/include/c++/v1/math.h:673:1: note: target of using declaration
asin(_A1 __lcpp_x) _NOEXCEPT {return asin((double)__lcpp_x);}
^
/usr/include/c++/v1/cmath:690:9: note: using declaration
using ::asin;
        ^
/usr/include/c++/v1/cmath:709:46: error: declaration conflicts with target of using declaration already in scope
inline _LIBCPP_INLINE_VISIBILITY float       atan(float __lcpp_x) _NOEXCEPT       {return atanf(__lcpp_x);}
                                             ^
/usr/include/c++/v1/math.h:678:46: note: target of using declaration
inline _LIBCPP_INLINE_VISIBILITY float       atan(float __lcpp_x) _NOEXCEPT       {return atanf(__lcpp_x);}
                                             ^
/usr/include/c++/v1/cmath:705:9: note: using declaration
using ::atan;
        ^
/usr/include/c++/v1/cmath:710:46: error: declaration conflicts with target of using declaration already in scope
inline _LIBCPP_INLINE_VISIBILITY long double atan(long double __lcpp_x) _NOEXCEPT {return atanl(__lcpp_x);}
                                             ^
/usr/include/c++/v1/math.h:679:46: note: target of using declaration
inline _LIBCPP_INLINE_VISIBILITY long double atan(long double __lcpp_x) _NOEXCEPT {return atanl(__lcpp_x);}
                                             ^
/usr/include/c++/v1/cmath:705:9: note: using declaration
using ::atan;
        ^
/usr/include/c++/v1/cmath:716:1: error: declaration conflicts with target of using declaration already in scope
atan(_A1 __lcpp_x) _NOEXCEPT {return atan((double)__lcpp_x);}
^
/usr/include/c++/v1/math.h:685:1: note: target of using declaration
atan(_A1 __lcpp_x) _NOEXCEPT {return atan((double)__lcpp_x);}
^
/usr/include/c++/v1/cmath:705:9: note: using declaration
using ::atan;
        ^
/usr/include/c++/v1/cmath:724:46: error: declaration conflicts with target of using declaration already in scope
inline _LIBCPP_INLINE_VISIBILITY float       atan2(float __lcpp_y, float __lcpp_x) _NOEXCEPT             {return atan2f(__lcpp_y, __lcpp_x);}
                                             ^
/usr/include/c++/v1/math.h:690:46: note: target of using declaration
inline _LIBCPP_INLINE_VISIBILITY float       atan2(float __lcpp_y, float __lcpp_x) _NOEXCEPT             {return atan2f(__lcpp_y, __lcpp_x);}
                                             ^
/usr/include/c++/v1/cmath:720:9: note: using declaration
using ::atan2;
        ^
/usr/include/c++/v1/cmath:725:46: error: declaration conflicts with target of using declaration already in scope
inline _LIBCPP_INLINE_VISIBILITY long double atan2(long double __lcpp_y, long double __lcpp_x) _NOEXCEPT {return atan2l(__lcpp_y, __lcpp_x);}
                                             ^
/usr/include/c++/v1/math.h:691:46: note: target of using declaration
inline _LIBCPP_INLINE_VISIBILITY long double atan2(long double __lcpp_y, long double __lcpp_x) _NOEXCEPT {return atan2l(__lcpp_y, __lcpp_x);}
                                             ^
/usr/include/c++/v1/cmath:720:9: note: using declaration
using ::atan2;
        ^
/usr/include/c++/v1/cmath:736:1: error: declaration conflicts with target of using declaration already in scope
atan2(_A1 __lcpp_y, _A2 __lcpp_x) _NOEXCEPT
^
/usr/include/c++/v1/math.h:702:1: note: target of using declaration
atan2(_A1 __lcpp_y, _A2 __lcpp_x) _NOEXCEPT
^
/usr/include/c++/v1/cmath:720:9: note: using declaration
using ::atan2;
        ^
/usr/include/c++/v1/cmath:750:46: error: declaration conflicts with target of using declaration already in scope
inline _LIBCPP_INLINE_VISIBILITY float       ceil(float __lcpp_x) _NOEXCEPT       {return ceilf(__lcpp_x);}
                                             ^
/usr/include/c++/v1/math.h:713:46: note: target of using declaration
inline _LIBCPP_INLINE_VISIBILITY float       ceil(float __lcpp_x) _NOEXCEPT       {return ceilf(__lcpp_x);}
                                             ^
/usr/include/c++/v1/cmath:746:9: note: using declaration
using ::ceil;
        ^
/usr/include/c++/v1/cmath:751:46: error: declaration conflicts with target of using declaration already in scope
inline _LIBCPP_INLINE_VISIBILITY long double ceil(long double __lcpp_x) _NOEXCEPT {return ceill(__lcpp_x);}
                                             ^
/usr/include/c++/v1/math.h:714:46: note: target of using declaration
inline _LIBCPP_INLINE_VISIBILITY long double ceil(long double __lcpp_x) _NOEXCEPT {return ceill(__lcpp_x);}
                                             ^
/usr/include/c++/v1/cmath:746:9: note: using declaration
using ::ceil;
        ^
/usr/include/c++/v1/cmath:757:1: error: declaration conflicts with target of using declaration already in scope
ceil(_A1 __lcpp_x) _NOEXCEPT {return ceil((double)__lcpp_x);}
^
/usr/include/c++/v1/math.h:720:1: note: target of using declaration
ceil(_A1 __lcpp_x) _NOEXCEPT {return ceil((double)__lcpp_x);}
^
/usr/include/c++/v1/cmath:746:9: note: using declaration
using ::ceil;
        ^
fatal error: too many errors emitted, stopping now [-ferror-limit=]
20 errors generated.
*** Error code 1

Stop.
make[3]: stopped in /usr/src/lib/clang/libllvmsupport
*** Error code 1

Stop.
make[2]: stopped in /usr/src
*** Error code 1

Stop.
make[1]: stopped in /usr/src
*** Error code 1

Stop.
make: stopped in /usr/src

Solusi yang saya lakukan adalah sbb:
Keyword ada di /usr/include/c++/v1/cmath:746, error itu kurang lebih seputar header declaration konflik dengan header yang sudah terinstall sebelomnya. Tipe data long double sepertinya tidak dapat didefinisikan di scope ketika proses build object file. Temukan file cmath di /usr dengan perintah:

root:/usr# find . -type f -name "cmath"
./src/contrib/libstdc++/include/tr1/cmath
./src/contrib/libc++/include/cmath (cmath dari source SVN)
./include/c++/v1/cmath (cmath yang bermasalah)
./local/lib/gcc5/include/c++/ext/cmath
./local/lib/gcc5/include/c++/tr1/cmath
./local/lib/gcc5/include/c++/cmath

OK, kita liat susunan direktori & filenya banyak kemiripan antara /usr/include/c++/v1/ dengan /usr/src/contrib/libc++/include/. Kita tinggal copykan saja tapi sebelomnya kita backup terlebih dahulu.

root:~# cd /usr/include/c++
root:/usr/include/c++# mv v1 v1.old
root:/usr/include/c++# cp -rp /usr/src/contrib/libc++/include .
root:/usr/include/c++# mv include v1

Silahkan dicoba kembali proses make buildworld, saya mengalami kekurangan dua file header yg dibutuhkan yaitu cxxabi.h dan unwind.h, silahkan kita cari lagi kedua file ini di /usr/src dan kopikan saja:

root:/usr/include/c++/v1# find /usr/src -type f -name "cxxabi.h"
/usr/src/contrib/libstdc++/libsupc++/cxxabi.h
/usr/src/contrib/libcxxrt/cxxabi.h (Kita ambil yang ini)
root:/usr/include/c++/v1# cp /usr/src/contrib/libcxxrt/cxxabi.h .
root:/usr/include/c++/v1# find /usr/src -type f -name "unwind.h"
/usr/src/sys/ia64/include/unwind.h
/usr/src/contrib/libcxxrt/unwind.h
/usr/src/contrib/llvm/tools/clang/lib/Headers/unwind.h (Kita ambil yang ini)
/usr/src/contrib/libexecinfo/unwind.h
/usr/src/include/unwind.h
root:/usr/include/c++/v1# cp /usr/src/contrib/llvm/tools/clang/lib/Headers/unwind.h .

Silahkan make buildworld kembali, jika ada error coba teliti stderr di consolenya. Dan silahkan tebak2 lagi seperti contoh langkah diatas :-).