C ++ gmp和homebrew

Question

我在Mac上，我通過homebrew安裝了gcc和gmp 。

為了測試我的安裝，我從這里嘗試了一個簡單的例子：

#include <iostream>
#include <gmpxx.h>
using namespace std;
int
main (void)
{
mpz_class a, b, c;

a = 1234;
b = "-5678";
c = a+b;
cout << "sum is " << c << "\n";
cout << "absolute value is " << abs(c) << "\n";

return 0;
}

首先，如果我嘗試g++ test.cpp -lgmpxx -lgmp它會抱怨

test.cpp:9:19: fatal error: gmpxx.h: No such file or directory
 #include <gmpxx.h>
                   ^
compilation terminated.

所以我試過g++ test.cpp -lgmpxx -lgmp -I/usr/local/include/

ld: library not found for -lgmpxx
collect2: error: ld returned 1 exit status

那么我試過g++ test.cpp -lgmpxx -lgmp -I/usr/local/include/ -L/usr/local/lib/

Undefined symbols for architecture x86_64:
  "operator<<(std::basic_ostream<char, std::char_traits<char> >&, __mpz_struct const*)", referenced from:
      std::basic_ostream<char, std::char_traits<char> >& operator<< <__mpz_struct [1], __mpz_struct [1]>(std::basic_ostream<char, std::char_traits<char> >&, __gmp_expr<__mpz_struct [1], __mpz_struct [1]> const&) in ccPugkZ3.o
      std::basic_ostream<char, std::char_traits<char> >& operator<< <__mpz_struct [1], __gmp_unary_expr<__gmp_expr<__mpz_struct [1], __mpz_struct [1]>, __gmp_abs_function> >(std::basic_ostream<char, std::char_traits<char> >&, __gmp_expr<__mpz_struct [1], __gmp_unary_expr<__gmp_expr<__mpz_struct [1], __mpz_struct [1]>, __gmp_abs_function> > const&) in ccPugkZ3.o
ld: symbol(s) not found for architecture x86_64
collect2: error: ld returned 1 exit status

有趣的是，如果我用cout g++ test.cpp -lgmpxx -lgmp -I/usr/local/include/ -L/usr/local/lib/ && ./a.out並嘗試g++ test.cpp -lgmpxx -lgmp -I/usr/local/include/ -L/usr/local/lib/ && ./a.out則沒有投訴。 特別是線c = a+b; 不需要被評論出來，所以我覺得似乎正在發生一些事情。

我錯過了什么？ 如何編譯示例代碼？

編輯：

按照@Will的建議，我試過g++ test.cpp -lgmpxx -lgmp -I/usr/local/include/ -L/usr/local/lib/ -m32

ld: warning: ld: warning: ignoring file /usr/local/lib//libgmpxx.dylib, file was built for x86_64 which is not the architecture being linked (i386): /usr/local/lib//libgmpxx.dylibignoring file /usr/local/lib//libgmp.dylib, file was built for x86_64 which is not the architecture being linked (i386): /usr/local/lib//libgmp.dylib

Undefined symbols for architecture i386:
  "operator<<(std::basic_ostream<char, std::char_traits<char> >&, __mpz_struct const*)", referenced from:
      std::basic_ostream<char, std::char_traits<char> >& operator<< <__mpz_struct [1], __mpz_struct [1]>(std::basic_ostream<char, std::char_traits<char> >&, __gmp_expr<__mpz_struct [1], __mpz_struct [1]> const&) in ccrPv2wC.o
      std::basic_ostream<char, std::char_traits<char> >& operator<< <__mpz_struct [1], __gmp_unary_expr<__gmp_expr<__mpz_struct [1], __mpz_struct [1]>, __gmp_abs_function> >(std::basic_ostream<char, std::char_traits<char> >&, __gmp_expr<__mpz_struct [1], __gmp_unary_expr<__gmp_expr<__mpz_struct [1], __mpz_struct [1]>, __gmp_abs_function> > const&) in ccrPv2wC.o
  "___gmpz_abs", referenced from:
      __gmp_abs_function::eval(__mpz_struct*, __mpz_struct const*) in ccrPv2wC.o
  "___gmpz_add", referenced from:
      __gmp_binary_plus::eval(__mpz_struct*, __mpz_struct const*, __mpz_struct const*) in ccrPv2wC.o
  "___gmpz_clear", referenced from:
      __gmp_expr<__mpz_struct [1], __mpz_struct [1]>::~__gmp_expr() in ccrPv2wC.o
  "___gmpz_init", referenced from:
      __gmp_expr<__mpz_struct [1], __mpz_struct [1]>::__gmp_expr() in ccrPv2wC.o
      __gmp_expr<__mpz_struct [1], __mpz_struct [1]>::__gmp_expr<__gmp_unary_expr<__gmp_expr<__mpz_struct [1], __mpz_struct [1]>, __gmp_abs_function> >(__gmp_expr<__mpz_struct [1], __gmp_unary_expr<__gmp_expr<__mpz_struct [1], __mpz_struct [1]>, __gmp_abs_function> > const&) in ccrPv2wC.o
  "___gmpz_set_si", referenced from:
      __gmp_expr<__mpz_struct [1], __mpz_struct [1]>::assign_si(long) in ccrPv2wC.o
  "___gmpz_set_str", referenced from:
      __gmp_expr<__mpz_struct [1], __mpz_struct [1]>::operator=(char const*) in ccrPv2wC.o
ld: symbol(s) not found for architecture i386
collect2: error: ld returned 1 exit status

如果我正確理解錯誤消息，似乎庫確實是為64位構建的，甚至聲明mpz_class a, b, c將無法使用-m32進行編譯。

Answer 1

從這個答案，嘗試運行xcode-select --install 。

在mac上，默認情況下，g ++（clang）無法搜索/ usr / local / include和/ usr / local / lib