Valgrind 上的内存堆和泄漏总结
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【中文标题】Valgrind 上的内存堆和泄漏总结【英文标题】：Memory Heap and Leak Summary on Valgrind 【发布时间】：2022-01-13 16:58:52 【问题描述】：我们学校的提交都是通过矩阵使用 valgrind 的，它逐行检查输出。但是，在提交时，我收到“检测到内存错误”。
编译结果：
Success! No errors or warnings...
执行：
Script started, file is student_output.txt
Script started, file is student_output.txt
==110143== Memcheck, a memory error detector
==110143== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==110143== Using Valgrind-3.15.0 and LibVEX; rerun with -h for copyright info
==110143== Command: ms
==110143==
Loading Data
Library Application:
输入数据时：
Publication Title: e
==111103== Conditional jump or move depends on uninitialised value(s)
==111103== at 0x404318: sdds::LibApp::search(int, char) (LibApp.cpp:145)
==111103== by 0x404ABC: sdds::LibApp::removePublication() (LibApp.cpp:329)
==111103== by 0x404DC1: sdds::LibApp::run() (LibApp.cpp:415)
==111103== by 0x404F6F: runLibApp(char const*) (LibAppMain_prof.cpp:9)
==111103== by 0x405084: main (LibAppMain_prof.cpp:20)
==111103==
其他信息
我在添加出版物时也遇到了错误（使用 newPublication() 函数），它位于下面的同一文件中。
==140314== Use of uninitialised value of size 8
==140314== at 0x404926: sdds::LibApp::newPublication() (LibApp.cpp:282)
==140314== by 0x404DAA: sdds::LibApp::run() (LibApp.cpp:411)
==140314== by 0x404F6F: runLibApp(char const*) (LibAppMain_prof.cpp:9)
==140314== by 0x405084: main (LibAppMain_prof.cpp:20)
==140314==
==140314== Use of uninitialised value of size 8
==140314== at 0x40493F: sdds::LibApp::newPublication() (LibApp.cpp:284)
==140314== by 0x404DAA: sdds::LibApp::run() (LibApp.cpp:411)
==140314== by 0x404F6F: runLibApp(char const*) (LibAppMain_prof.cpp:9)
==140314== by 0x405084: main (LibAppMain_prof.cpp:20)
==140314==
文件发布在下面。
LibApp.cpp
#define _CRT_SECURE_NO_WARNINGS
#include <fstream>
#include <iostream>
#include <fstream>
#include <cstring>
#include <iomanip>
#include "LibApp.h"
#include "Book.h"
#include "PublicationSelector.h"
namespace sdds
int NOLP=0;
int LLRN=0;
bool LibApp::confirm(const char* message)
Menu conf(message);
conf<<"Yes";
int t_return = conf.run();
if(t_return) return true;
return false;
LibApp::LibApp(const char filename[256])
m_mainMenu << "Add New Publication"
<< "Remove Publication"
<< "Checkout publication from library"
<<"Return publication to library";
m_exitMenu << "Save changes and exit" << "Cancel and go back to the main menu";
strcpy(m_filename, filename);
m_publicationMenu << "Book" << "Publication" ;
load();
LibApp::~LibApp()
for (int i = 0; i< NOLP ; i++)
delete PPA[i];
void LibApp::load()
std::cout<<"Loading Data\n";
std::ifstream infile(m_filename);
char type;
for (int i = 0; infile ; i++)
infile >> type;
infile.ignore();
if (infile)
if (type == 'P')
PPA[i] = new Publication;
else if (type == 'B')
PPA[i] = new Book;
else std::cout<<"no data\n";
if (PPA[i] && i < SDDS_LIBRARY_CAPACITY )
infile >> *PPA[i];
LLRN=PPA[i]->getRef();
NOLP++;
void LibApp::save()
std::cout<<"Saving Data\n";
std::ofstream outfile(m_filename);
for (int i = 0; i < NOLP; i++)
if (PPA[i]->getRef()!=0)
outfile << *PPA[i] << std::endl;
void prnPub(Publication* p[], int size, int ref)
int i;
for (i = 0; i < size; i++)
if (ref == p[i]->getRef())
std::cout << *p[i] << std::endl;
i = size;
int LibApp::search(int option,char type)
PublicationSelector ps("Select one of the following found matches:", 15);
std::cout<<"Publication Title: ";
char title[256];
std::cin.getline(title,256);
if(option==1)
for (int i = 0; i< NOLP; i++)
if (strstr(*PPA[i],title) && PPA[i]->getRef()!=0 && type==PPA[i]->type())
ps << PPA[i];
else if(option==2)
for (int i = 0; i< NOLP; i++)
if (strstr(*PPA[i],title) && !PPA[i]->onLoan() && PPA[i]->getRef()!=0 && type==PPA[i]->type())
ps << PPA[i];
else if(option==3)
for (int i = 0; i< NOLP; i++)
if (strstr(*PPA[i],title) && PPA[i]->onLoan() && PPA[i]->getRef()!=0 && type==PPA[i]->type())
ps << PPA[i];
int ref = 0;
if (ps)
ps.sort();
ref = ps.run();
if (ref)
prnPub(PPA, NOLP , ref);
else
std::cout << "Aborted!\n";
else
std::cout << "No matches to found!" << std::endl;
return ref;
void LibApp::returnPub()
std::cout<<"Return publication to the library\n";
int i=m_publicationMenu.run();
char type;
if(i==1) type='B';
else type='P';
int ref=search(3,type);
if(ref!=0 && confirm("Returning publication?"))
Date date=getPub(ref)->checkoutDate();
Date today;
int days=today-date;
days-=15;
if(days>0)
std::cout << std::fixed;
std::cout << std::setprecision(2);
std::cout<<"Please pay $"<<float(days)*(0.5)<<" penalty for being "<<days<<" days late!\n";
getPub(ref)->set(0);
std::cout<<"Publication returned\n";
m_changed=true;
void LibApp::newPublication()
if( NOLP >= SDDS_LIBRARY_CAPACITY )
std::cout<<"Library is at its maximum capacity!\n";
return;
std::cout<<"Adding new publication to library\n";
int i=m_publicationMenu.run();
Publication *p=nullptr;
if(i==0)
std::cout<<"Aborted!\n";
return;
else if(i==1)
p = new Book;
std::cin >> *p;
else if( i==2 )
p = new Publication;
std::cin >> *p;
if(std::cin.fail())
std::cout<<"\nAborted!\n";
exit(0);
if(confirm("Add this publication to library?"))
m_changed = true;
PPA[NOLP]=p;
LLRN=PPA[NOLP]->getRef();
NOLP++;
std::cout<<"Publication added\n";
if( !*p )
std::cout<<"Failed to add publication!\n";
delete p;
Publication* LibApp::getPub(int libRef)
for(int i=0;i<NOLP;i++)
if(libRef==PPA[i]->getRef()) return PPA[i];
return nullptr;
void LibApp::removePublication()
//std::cout<<;
std::cout<<"Removing publication from the library\n";
int i=m_publicationMenu.run();
char type;
if(i==1) type='B';
else
type='P';
int ref=search(1,type);
if(ref!=0 && confirm("Remove this publication from the library?"))
m_changed = true;
getPub(ref)->setRef(0);
std::cout<<"Publication removed\n";
void LibApp::checkOutPub()
std::cout<<"Checkout publication from the library\n";
int i=m_publicationMenu.run();
char type;
if(i==1) type='B';
else type='P';
int ref=search(2,type);
if(ref!=0 && confirm("Check out publication?"))
m_changed = true;
int mn;
std::cout << "Enter Membership Number: ";
while (1)
std::cin>>mn;
if(mn > 9999 && mn <= 99999 ) break;
std::cout<<"Invalid membership number, try again: ";
getPub(ref)->set(mn);
std::cout<<"Publication checked out\n";
LibApp::LibApp()
m_mainMenu << "Add New Publication"
<< "Remove Publication"
<< "Checkout publication from library"
<<"Return publication to library";
m_exitMenu << "Save changes and exit" << "Cancel and go back to the main menu";
load();
void LibApp::run()
while(1)
int option = m_mainMenu.run();
if( option == 1 )
newPublication();
else if( option == 2 )
removePublication();
else if( option == 3 )
checkOutPub();
else if( option == 4 )
returnPub();
else if( option == 0 )
if(m_changed)
int opn = m_exitMenu.run();
if( opn == 1 )
save();
break;
else if( opn == 2 )
;
else if( opn == 0)
if(confirm("This will discard all the changes are you sure?"))
break;
else break;
std::cout<<std::endl;
std::cout<<std::endl;
std::cout<<"-------------------------------------------\n";
std::cout<<"Thanks for using Seneca Library Application\n";
请帮帮我。我今天提交的内容是我知道问题是什么。
【问题讨论】：
Stack Overflow 不是免费的作业帮助服务。 【参考方案1】：就像错误信息说的那样：
Conditional jump or move depends on uninitialised value(s)
==111103== at 0x404318: sdds::LibApp::search(int, char) (LibApp.cpp:145)
在 LibApp.cpp 的第 145 行有一个 if 语句（或逻辑上等同于 if 语句的东西），它根据从未初始化为任何值的变量决定采用哪条路径；因此，该 if-test 的行为是未定义的（即 if 可以采用任何一种方式，具体取决于当时该变量的内存位置发生的任意数据）。
因此，您需要查看第 145 行 if-test 中存在的变量，以确定哪些变量没有被预先设置，然后通过确保它们首先被设置来修复错误.
如有必要，您可以添加临时 if-tests 以激发 valgrind 为您提供更多结果：
if (some_suspect_var != 0) fprintf(stderr, “Yea\n”);
else fprintf(stderr, “Nay\n”);
…那么如果你在那个 if 行上得到一个 valgrind 错误，你就知道 some_suspect_var 在那一点上是未初始化的。
【讨论】：
if 语句不是问题。出于某种原因，我的内存没有被动态分配和释放。有人能解决这个问题吗？ 解决问题的唯一方法是编译/运行/测试/诊断/重复直到您了解故障，此时您也将了解如何修复它。如果您发布的代码可以由其他人编译，其他人可能会为您执行此操作，但由于它只是部分列表，其他人将无法编译和运行它，这意味着它取决于您弄清楚。以上是关于Valgrind 上的内存堆和泄漏总结的主要内容，如果未能解决你的问题，请参考以下文章