Question

我目前正试图让https://github.com/aleju/mario-ai的Mario项目在我的ubuntu（16.04）系统上运行。我按照教程并已经解决了一些错误，但是现在我在lsnes模拟器上得到的东西看起来像编译错误，这对我来说没有意义。

我的命令是LDFLAGS="-L/usr/lib -L/usr/local/lib -L/usr/lib/x86_64-linux-gnu" CFLAGS="-I/usr/include -I/usr/local/include -I/usr/include/lua5.1" make。我添加了试图解决我的上一个错误的标志。

这是我得到的错误：

...
g++ -c -o core.o core.cpp -I../../../include -I../../../bsnes -I/usr/include -I/usr/local/include -I/usr/include/lua5.1 -std=gnu++0x -pthread -g -DNATIVE_THREADS -DUSE_LIBGCRYPT_SHA256 -I/usr/include/lua5.1  -DBSNES_IS_COMPAT -DBSNES_HAS_DEBUGGER -DBSNES_VERSION=\"085\" -DLIBSNES_INCLUDE_FILE=\"ui-libsnes/libsnes.hpp\"  -Wreturn-type
In file included from ../../../bsnes/nall/array.hpp:10:0,
             from ../../../bsnes/snes/snes.hpp:28,
             from core.cpp:49:
../../../bsnes/nall/bit.hpp: In instantiation of ‘constexpr unsigned int nall::uclip(unsigned int) [with int bits = 24]’:
../../../bsnes/snes/cpu/core/registers.hpp:52:69:   required from here
../../../bsnes/nall/bit.hpp:13:3: error: body of constexpr function ‘constexpr unsigned int nall::uclip(unsigned int) [with int bits = 24]’ not a return-statement
   }
   ^
../../../bsnes/nall/bit.hpp: In instantiation of ‘constexpr unsigned int nall::uclip(unsigned int) [with int bits = 2]’:
../../../bsnes/nall/varint.hpp:32:55:   required from ‘nall::uint_t<bits>::uint_t(unsigned int) [with unsigned int bits = 2u]’
../../../bsnes/snes/controller/controller.hpp:27:33:   required from here
../../../bsnes/nall/bit.hpp:13:3: error: body of constexpr function ‘constexpr unsigned int nall::uclip(unsigned int) [with int bits = 2]’ not a return-statement
Makefile:44: die Regel für Ziel „core.o“ scheiterte
make[3]: *** [core.o] Fehler 1
...

bit.hpp：

#ifndef NALL_BIT_HPP
#define NALL_BIT_HPP

namespace nall {
  template<int bits> constexpr inline unsigned uclamp(const unsigned x) {
    enum { y = (1U << (bits - 1)) + ((1U << (bits - 1)) - 1) };
    return y + ((x - y) & -(x < y));  //min(x, y);
  }

  template<int bits> constexpr inline unsigned uclip(const unsigned x) {
    enum { m = (1U << (bits - 1)) + ((1U << (bits - 1)) - 1) };
    return (x & m);
  }

  template<int bits> constexpr inline signed sclamp(const signed x) {
    enum { b = 1U << (bits - 1), m = (1U << (bits - 1)) - 1 };
    return (x > m) ? m : (x < -b) ? -b : x;
  }

  template<int bits> constexpr inline signed sclip(const signed x) {
    enum { b = 1U << (bits - 1), m = (1U << bits) - 1 };
    return ((x & m) ^ b) - b;
  }

  namespace bit {
    //lowest(0b1110) == 0b0010
    template<typename T> constexpr inline T lowest(const T x) {
      return x & -x;
    }

    //clear_lowest(0b1110) == 0b1100
    template<typename T> constexpr inline T clear_lowest(const T x) {
      return x & (x - 1);
    }

    //set_lowest(0b0101) == 0b0111
    template<typename T> constexpr inline T set_lowest(const T x) {
      return x | (x + 1);
    }

    //round up to next highest single bit:
    //round(15) == 16, round(16) == 16, round(17) == 32
    inline unsigned round(unsigned x) {
      if((x & (x - 1)) == 0) return x;
      while(x & (x - 1)) x &= x - 1;
      return x << 1;
    }
  }
}

#endif

我对C ++并不熟悉，但该文件看起来不错。

你知道这可能是什么问题吗？我已经尝试过在我在这里找到的关于lsnes的唯一其他问题中提出的解决方案（link error with "undefined lua_xxxxx" when building lsnes），但它没有帮助。

Answer 1

我只是仔细看了你对g++的电话，你正在使用-std=c++0x选项。这告诉编译器使用C ++ 11标准。但是，正如我的评论中所述，您发布的代码至少需要C ++ 14才能运行。因此，请使用选项-std=c++14，它应该可以正常工作。

在ubuntu上编译lsnes模拟器时出错

1 个答案: