尝试从方法返回指向对象的指针时出现分段错误

Segmentation fault while trying to return a pointer to object from a method

本文关键字:指针 错误 分段 对象 方法 返回      更新时间:2023-10-16

g++在我试图从classA的方法返回classB的对象时抛出"segmentation fault"。我不知道如何修复这个错误,如果有人能告诉我为什么会发生这个错误,我将不胜感激。所以…这是代码:

classA.h

#include "classB.h"
#ifndef _CLASS_A_H_
#define _CLASS_A_H_
class ClassA{
private:
int id;
ClassB *ptr_classB;
public:
ClassA();
ClassA(int id, std::string name);
inline void setID(int id){this->id = id;}
inline int getID(){return this->id;}
inline ClassB getClassB(){return this->ptr_classB;}
};
#endif

classA.cpp

#include "classA.h"
#include "classB.h"
ClassA::ClassA(){
this->id = 0;
ptr_classB = new ClassB();
}

classB.h

#ifndef _CLASS_B_H
#define _CLASS_B_H
class ClassB{
private:
std::string name;
public:
ClassB();
inline std::string getName(){return this->name;}
};
#endif

classB.cpp

#include <string>
#include "classB.h"
ClassB::ClassB(){
this->name = "default";
}

main.cpp

#include <iostream>
#include "classA.h"
using namespace std;
int main(){
ClassA *ptr_classA = new ClassA();
cout << ptr_classA->getClassB().getName()  << endl;
//asd
return 0;
}

Makefile

SRC=SRC

INC=包括

OBJ=目标

BIN=仓

LIB=LIB

CXX=g++

CPPFLAGS=-c-I$(INC)/-std=c++11

全部:$(BIN)/主

$(BIN)/main:$(OBJ)/main.o

$(CXX) -o $(BIN)/main $(OBJ)/main.o -Llib/ -lclasses

$(OBJ)/main.o:$(SRC)/main.cpp

$(CXX) $(CPPFLAGS) $(SRC)/main.cpp -o $(OBJ)/main.o

$(OBJ)/calassA.o:$(SRC)/classA.cpp$(INC)/cclassA.h$(INC)/classB.h

$(CXX) $(CPPFLAGS) $(SRC)/classA.cpp -o $(OBJ)/classA.o

$(OBJ)/classB.o:$(SRC)/classB.cpp$(INC)/cclassB.h

$(CXX) $(CPPFLAGS) $(SRC)/classB.cpp -o $(OBJ)/classB.o

$(LIB)/libclasses.a:$(OBJ)/classA.o

ar rsv $(LIB)/libclasses.a $(OBJ)/classA.o 

已清理代码:

class ClassA ;
class ClassB ;
class ClassB{
private:
int n;
public:
ClassB();
inline void set_n(int n){this->n =n;}
inline int get_n(){return this->n;}
};
class ClassA{
private:
ClassB *ptr_classb;
public:
ClassA();
inline ClassB getClassBObject(){return *ptr_classb;}
};
ClassB::ClassB(){
this->n = 0;
}
ClassA::ClassA(){
ptr_classb = new ClassB();
}
#include <iostream>
int main(){
ClassA *ptr_classA = new ClassA();
std::cout << ptr_classA->getClassBObject().get_n() << std::endl;
return 0;
}

在COMPIL时间更正错误后,编译和执行都很好,这让我想知道:你到底是怎么编译得到segfault的?