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我正在使用 Dr. Memory 对我今天写的一个 C 程序进行内存调试。使用 MinGW 的 gcc 编译的这个程序只有在我从调试器 gdb 运行它时才有效，所以我假设它是内存错误。内存博士返回给我的 results.txt 文件类似于：

Dr. Memory version 1.5.0 build 5 builton Aug 31 2012 16:19:51
Application cmdline: ""c:\Users\Lincoln\Desktop\USACO\gift1.exe""
Recorded 63 suppression(s) from default c:\Program Files\Dr. Memory/bin/suppress-default.txt

Error #1: UNINITIALIZED READ: reading register eflags
# 0 replace_memcmp               [d:\derek\drmemory\withwiki\trunk\drmemory\replace.c:557]
# 1 parseInputs                  [c:\Users\Lincoln\Desktop\USACO/gift1.c:55]
# 2 main                         [c:\Users\Lincoln\Desktop\USACO/gift1.c:126]
Note: @0:00:00.473 in thread 3824
Note: instruction: jnz    $0x7388a607

Error #2: UNINITIALIZED READ: reading register eax
# 0 parseInputs               [c:\Users\Lincoln\Desktop\USACO/gift1.c:55]
# 1 main                      [c:\Users\Lincoln\Desktop\USACO/gift1.c:126]
Note: @0:00:00.473 in thread 3824
Note: instruction: test   %eax %eax

Error #3: UNINITIALIZED READ: reading register esi
# 0 replace_memcmp               [d:\derek\drmemory\withwiki\trunk\drmemory\replace.c:556]
# 1 parseInputs                  [c:\Users\Lincoln\Desktop\USACO/gift1.c:55]
# 2 main                         [c:\Users\Lincoln\Desktop\USACO/gift1.c:126]
Note: @0:00:00.474 in thread 3824
Note: instruction: movzx  (%esi,%ecx,1) -> %edi

Error #4: UNADDRESSABLE ACCESS: reading 0x00000004-0x00000005 1 byte(s)
# 0 replace_memcmp               [d:\derek\drmemory\withwiki\trunk\drmemory\replace.c:556]
# 1 parseInputs                  [c:\Users\Lincoln\Desktop\USACO/gift1.c:55]
# 2 main                         [c:\Users\Lincoln\Desktop\USACO/gift1.c:126]
Note: @0:00:00.474 in thread 3824
Note: instruction: movzx  (%esi,%ecx,1) -> %edi

我不知道如何阅读这篇文章，也不知道从哪里开始尝试修复我的程序。这些错误消息是什么意思，我该如何解决？

编辑：这是我的代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

struct personsData {
    char * name;
    int accountMoney, receivedMoney, numAquaintances;
};

void parseInputs( FILE * fin, int NP, struct personsData * person ) {

    int i;
    for ( i = 0; i < NP; i ++ )
        fscanf( fin, "%s", person[i].name );

    char * tempName_1;
    while ( !feof( fin ) ) {

        tempName_1 = malloc ( sizeof( char ) * 15 );
        fscanf( fin, "%s", tempName_1 );

        int index = 0;
        while ( memcmp( tempName_1, person[index].name, 15 ) != 0 )
            index ++;
        free( tempName_1 );

        fscanf( fin, "%d %d", &person[index].accountMoney, &person[index].numAquaintances );

        int b;
        char * tempName_2;
        for ( b = 0; b < person[index].numAquaintances; b ++) {
            tempName_2 = malloc( sizeof( char ) * 15 );
            fscanf( fin, "%s", tempName_2 );
            i = 0;
            while ( memcmp( tempName_2, person[i].name, 15 ) != 0 )
                i ++;

            free( tempName_2 );

            person[i].receivedMoney += ( int ) floor( person[index].accountMoney / person[index].numAquaintances );
            person[index].accountMoney = floor( person[index].accountMoney / person[index].numAquaintances ) * person[index].numAquaintances;

        }
    }

}

int main() {

    FILE * fin  = fopen ("gift1.in",  "r");
    FILE * fout = fopen ("gift1.out", "w");

    int NP;
    fscanf( fin, "%d", &NP);

    struct personsData person[NP];
    int i;
    for ( i = 0; i < NP; i ++ ) {
        person[i].accountMoney = 0;
        person[i].receivedMoney = 0;
        person[i].numAquaintances = 0;
        person[i].name = ( char * ) malloc ( sizeof( char ) * 15 );
    }

    parseInputs( fin, NP, person );

    for ( i = 0; i < NP; i ++ ) {
        // print to output file (and also to console for development purposes
        fprintf( fout,  "%s %d\n", person[i].name, person[i].receivedMoney - person[i].accountMoney );
        printf(         "%s %d\n", person[i].name, person[i].receivedMoney - person[i].accountMoney );
    }

    for ( i = 0; i < NP; i ++ ) {
        free( person[i].name );
    }

    exit(0);
}

这是输入文件gift1.in：

5
dave
laura
owen
vick
amr
dave
200 3
laura
owen
vick
owen
500 1
dave
amr
150 2
vick
owen
laura
0 2
amr
vick
vick
0 0
4

2 回答 2

1

你对 x86 汇编很熟悉吗？如果你不是，其中一些错误将很难解释。无论哪种方式，它都会告诉您回溯中涉及哪些代码行，例如第一行：

# 0 replace_memcmp               [d:\derek\drmemory\withwiki\trunk\drmemory\replace.c:557]
# 1 parseInputs                  [c:\Users\Lincoln\Desktop\USACO/gift1.c:55]
# 2 main                         [c:\Users\Lincoln\Desktop\USACO/gift1.c:126]

通常，这些错误似乎表明您将未初始化的内存传递给memcmp()并取消引用 NULL 指针。但是，正如 Mitch 所建议的，我们需要查看代码才能确定。

于 2012-11-16T00:34:03.873 回答
0

我想知道您是否阅读了有关为 Dr Memory 准备程序的文档。看起来您使用过 Visual Studio，因此请使用 /Zi、/MD 或 /Mt、/Ob0、/Oy- 进行编译。确保它是 32 位的，因为 Dr Memory 不支持 64 位二进制文​​件。

这应该为您提供源代码行而不是机器指令的输出。

于 2012-11-16T00:36:43.953 回答