c++ - 生成文件:6:目标 'all' 的配方在 ubuntu-16.04 上失败

Question

g++ -std=c++11 -g -o run NumberNode.cpp LinkedList.cpp CarBST.cpp Queue.cpp CarNode.cpp Manager.cpp main.cpp NumberBST.cpp CarBST.h Queue.h CarNode.h Manager.h NumberBST.h NumberNode.h LinkedList.h
In file included from CarBST.h:2:0,
                 from NumberNode.h:2,
                 from NumberNode.cpp:1:
CarNode.h: In constructor ‘CarNode::CarNode(int)’:
CarNode.h:24:9: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null]
   state = NULL;
         ^
NumberNode.cpp: In destructor ‘NumberNode::~NumberNode()’:
NumberNode.cpp:13:9: warning: converting to non-pointer type ‘int’ from NULL [-Wconversion-null]
  number = NULL;
         ^
In file included from LinkedList.h:2:0,
                 from LinkedList.cpp:1:
CarNode.h: In constructor ‘CarNode::CarNode(int)’:
CarNode.h:24:9: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null]
   state = NULL;
         ^
In file included from CarBST.h:2:0,
                 from CarBST.cpp:1:
CarNode.h: In constructor ‘CarNode::CarNode(int)’:
CarNode.h:24:9: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null]
   state = NULL;
         ^
CarBST.cpp: In member function ‘void CarBST::Delete(int)’:
CarBST.cpp:90:21: warning: converting to non-pointer type ‘int’ from NULL [-Wconversion-null]
  int lastLocation = NULL; //leafNode \B0\E6\BF\EC \BAθ\F0\B3\EB\B5\E5\C0\C7 \B
                     ^
In file included from Queue.h:2:0,
                 from Queue.cpp:1:
CarNode.h: In constructor ‘CarNode::CarNode(int)’:
CarNode.h:24:9: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null]
   state = NULL;
         ^
In file included from CarNode.cpp:1:0:
CarNode.h: In constructor ‘CarNode::CarNode(int)’:
CarNode.h:24:9: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null]
   state = NULL;
         ^
CarNode.cpp: In destructor ‘CarNode::~CarNode()’:
CarNode.cpp:12:12: warning: converting to non-pointer type ‘int’ from NULL [-Wconversion-null]
  carNumber = NULL;
            ^
CarNode.cpp:14:8: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null]
  state = NULL;
        ^
In file included from LinkedList.h:2:0,
                 from Manager.h:11,
                 from Manager.cpp:6:
CarNode.h: In constructor ‘CarNode::CarNode(int)’:
CarNode.h:24:9: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null]
   state = NULL;
         ^
In file included from LinkedList.h:2:0,
                 from Manager.h:11,
                 from main.cpp:3:
CarNode.h: In constructor ‘CarNode::CarNode(int)’:
CarNode.h:24:9: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null]
   state = NULL;
         ^
In file included from CarBST.h:2:0,
                 from NumberNode.h:2,
                 from NumberBST.h:2,
                 from NumberBST.cpp:1:
CarNode.h: In constructor ‘CarNode::CarNode(int)’:
CarNode.h:24:9: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null]
   state = NULL;
         ^
NumberBST.cpp: In member function ‘void NumberBST::Delete(int)’:
NumberBST.cpp:119:21: warning: converting to non-pointer type ‘int’ from NULL [-Wconversion-null]
  int lastLocation = NULL; //leafNode \B0\E6\BF\EC \BAθ\F0\B3\EB\B5\E5\C0\C7 \B
                     ^
CarBST.h:1:9: warning: #pragma once in main file
 #pragma once
         ^
In file included from CarBST.h:2:0:
CarNode.h: In constructor ‘CarNode::CarNode(int)’:
CarNode.h:24:9: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null]
   state = NULL;
         ^
Queue.h:1:9: warning: #pragma once in main file
 #pragma once
         ^
In file included from Queue.h:2:0:
CarNode.h: In constructor ‘CarNode::CarNode(int)’:
CarNode.h:24:9: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null]
   state = NULL;
         ^
CarNode.h:1:9: warning: #pragma once in main file
 #pragma once
         ^
CarNode.h: In constructor ‘CarNode::CarNode(int)’:
CarNode.h:24:9: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null]
   state = NULL;
         ^
Manager.h:1:9: warning: #pragma once in main file
 #pragma once
         ^
In file included from LinkedList.h:2:0,
                 from Manager.h:11:
CarNode.h: In constructor ‘CarNode::CarNode(int)’:
CarNode.h:24:9: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null]
   state = NULL;
         ^
NumberBST.h:1:9: warning: #pragma once in main file
 #pragma once
         ^
In file included from CarBST.h:2:0,
                 from NumberNode.h:2,
                 from NumberBST.h:2:
CarNode.h: In constructor ‘CarNode::CarNode(int)’:
CarNode.h:24:9: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null]
   state = NULL;
         ^
NumberNode.h:1:9: warning: #pragma once in main file
 #pragma once
         ^
In file included from CarBST.h:2:0,
                 from NumberNode.h:2:
CarNode.h: In constructor ‘CarNode::CarNode(int)’:
CarNode.h:24:9: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null]
   state = NULL;
         ^
LinkedList.h:1:9: warning: #pragma once in main file
 #pragma once
         ^
In file included from LinkedList.h:2:0:
CarNode.h: In constructor ‘CarNode::CarNode(int)’:
CarNode.h:24:9: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null]
   state = NULL;
         ^
/tmp/ccYwuJus.o: In function `Manager::MOVE(int)':
/home/limsh/project/Manager.cpp:172: undefined reference to `CarBST::CarBST()'
/tmp/ccYwuJus.o: In function `Manager::Insert_BST(std::basic_ifstream<char, std::char_traits<char> >&)':
/home/limsh/project/Manager.cpp:363: undefined reference to `CarBST::CarBST()'
collect2: error: ld returned 1 exit status
Makefile:6: recipe for target 'all' failed
make: *** [all] Error 1

我不知道如何解决这个问题。

这个程序是在 VS2017 上运行的。

但是在 ubuntu 上，没有解决这个问题。

“makefile:6”是什么意思？

我在谷歌和堆栈溢出中找不到这个.....

而且，我听说即使有警告也能正常工作。所以我没有检查这些警告。

无论如何，请帮助..

Answer 1

这个

Makefile:6: recipe for target 'all' failed

意味着，如果没有指定其他目标，则隐式调用的目标“all”有错误，并且它在第 6 行的 Makefile 中定义。

底层错误是这个链接器错误:

undefined reference to `CarBST::CarBST()'

这是您必须解决的问题。你用来编译链接的命令是:

g++ -std=c++11 -g -o run NumberNode.cpp LinkedList.cpp CarBST.cpp Queue.cpp CarNode.cpp Manager.cpp main.cpp NumberBST.cpp CarBST.h Queue.h CarNode.h Manager.h NumberBST.h NumberNode.h LinkedList.h

CarBST.cpp 文件可能包含类定义，但存在于此。看起来没有无参数的构造函数；向类中添加一个或调用可用的构造函数。

此外，在编译器命令行指定头文件(*.h)并不常见，这些文件通常包含在源文件(*.cpp)中。

最后，您不应该忽略警告并检查为什么将 NULL 指针分配给 chars。应该是这样

state = 0;

或类似的。