Valgrind 使用 getline() 给出错误

Question

我有一个调用 getline() 的函数，它从标准文本文件中读取行。这些行以 \r\n 结尾，因为这是规范所要求的，因为它是 VCARD 文件的“互联网标准”。

无论如何，我通过 OpenSUSE 11.3 上的 Valgrind 运行这个宝贝，并使用最新的 GCC 和 Valgrind 版本；没有错误。然而，由于与这个问题无关的原因，我将发行版切换到 Back Track 4（基于 Ubuntu），现在我收到了大量的 Valgrind 错误：

    ==21536== Conditional jump or move depends on uninitialised value(s)
==21536==    at 0x40164A1: (within /lib/ld-2.11.1.so)
==21536==    by 0x4007C04: (within /lib/ld-2.11.1.so)
==21536==    by 0x4002A2C: (within /lib/ld-2.11.1.so)
==21536==    by 0x4014206: (within /lib/ld-2.11.1.so)
==21536==    by 0x4000C6C: (within /lib/ld-2.11.1.so)
==21536==    by 0x4000856: (within /lib/ld-2.11.1.so)
==21536==
==21536== Conditional jump or move depends on uninitialised value(s)
==21536==    at 0x40164AC: (within /lib/ld-2.11.1.so)
==21536==    by 0x4007C04: (within /lib/ld-2.11.1.so)
==21536==    by 0x4002A2C: (within /lib/ld-2.11.1.so)
==21536==    by 0x4014206: (within /lib/ld-2.11.1.so)
==21536==    by 0x4000C6C: (within /lib/ld-2.11.1.so)
==21536==    by 0x4000856: (within /lib/ld-2.11.1.so)
--21536-- Warning: DWARF2 CFI reader: unhandled DW_OP_ opcode 0x55
--21536-- Warning: DWARF2 CFI reader: unhandled DW_OP_ opcode 0x55
--21536-- DWARF2 CFI reader: unhandled CFI instruction 0:10
--21536-- DWARF2 CFI reader: unhandled CFI instruction 0:10
--21536-- DWARF2 CFI reader: unhandled CFI instruction 0:10
--21536-- DWARF2 CFI reader: unhandled CFI instruction 0:10
--21536-- DWARF2 CFI reader: unhandled CFI instruction 0:10
--21536-- DWARF2 CFI reader: unhandled CFI instruction 0:10
--21536-- DWARF2 CFI reader: unhandled CFI instruction 0:10
==21536==
==21536== Conditional jump or move depends on uninitialised value(s)
==21536==    at 0x400B217: (within /lib/ld-2.11.1.so)
==21536==    by 0x40031D0: (within /lib/ld-2.11.1.so)
==21536==    by 0x4014206: (within /lib/ld-2.11.1.so)
==21536==    by 0x4000C6C: (within /lib/ld-2.11.1.so)
==21536==    by 0x4000856: (within /lib/ld-2.11.1.so)
==21536==
==21536== Conditional jump or move depends on uninitialised value(s)
==21536==    at 0x400AF0F: (within /lib/ld-2.11.1.so)
==21536==    by 0x40031D0: (within /lib/ld-2.11.1.so)
==21536==    by 0x4014206: (within /lib/ld-2.11.1.so)
==21536==    by 0x4000C6C: (within /lib/ld-2.11.1.so)
==21536==    by 0x4000856: (within /lib/ld-2.11.1.so)
==21536==
==21536== Conditional jump or move depends on uninitialised value(s)
==21536==    at 0x400B27A: (within /lib/ld-2.11.1.so)
==21536==    by 0x40031D0: (within /lib/ld-2.11.1.so)
==21536==    by 0x4014206: (within /lib/ld-2.11.1.so)
==21536==    by 0x4000C6C: (within /lib/ld-2.11.1.so)
==21536==    by 0x4000856: (within /lib/ld-2.11.1.so)
==21536==
==21536== Conditional jump or move depends on uninitialised value(s)
==21536==    at 0x400A5DE: (within /lib/ld-2.11.1.so)
==21536==    by 0x40030FE: (within /lib/ld-2.11.1.so)
==21536==    by 0x4014206: (within /lib/ld-2.11.1.so)
==21536==    by 0x4000C6C: (within /lib/ld-2.11.1.so)
==21536==    by 0x4000856: (within /lib/ld-2.11.1.so)
==21536==
==21536== Conditional jump or move depends on uninitialised value(s)
==21536==    at 0x400A5E6: (within /lib/ld-2.11.1.so)
==21536==    by 0x40030FE: (within /lib/ld-2.11.1.so)
==21536==    by 0x4014206: (within /lib/ld-2.11.1.so)
==21536==    by 0x4000C6C: (within /lib/ld-2.11.1.so)
==21536==    by 0x4000856: (within /lib/ld-2.11.1.so)
==21536==
==21536== Conditional jump or move depends on uninitialised value(s)
==21536==    at 0x400AF0F: (within /lib/ld-2.11.1.so)
==21536==    by 0x40030FE: (within /lib/ld-2.11.1.so)
==21536==    by 0x4014206: (within /lib/ld-2.11.1.so)
==21536==    by 0x4000C6C: (within /lib/ld-2.11.1.so)
==21536==    by 0x4000856: (within /lib/ld-2.11.1.so)
==21536==
==21536== Invalid read of size 8
==21536==    at 0x40B4785: (within /lib/tls/i686/cmov/libc-2.11.1.so)
==21536==    by 0x8049EFB: main (vcutil.c:496)
==21536==  Address 0x419d1b0 is 8 bytes before a block of size 120 alloc'd
==21536==    at 0x4025D2E: malloc (vg_replace_malloc.c:207)
==21536==    by 0x409DF9D: getdelim (in /lib/tls/i686/cmov/libc-2.11.1.so)
==21536==    by 0x408F3A2: getline (in /lib/tls/i686/cmov/libc-2.11.1.so)
==21536==    by 0x804947C: getUnfolded (vcutil.c:299)
==21536==    by 0x8049EFB: main (vcutil.c:496)
==21536==
==21536== Conditional jump or move depends on uninitialised value(s)
==21536==    at 0x40B47AD: (within /lib/tls/i686/cmov/libc-2.11.1.so)
==21536==    by 0x8049EFB: main (vcutil.c:496)
==21536==
==21536== Conditional jump or move depends on uninitialised value(s)
==21536==    at 0x8049524: getUnfolded (vcutil.c:307)
==21536==    by 0x8049EFB: main (vcutil.c:496)

我特别不知道这些行所指的

--21536-- Warning: DWARF2 CFI reader: unhandled DW_OP_ opcode 0x55

含义。自从我改变发行版以来，这些都是新的。

无论如何，作为参考，这是我有问题的函数：

VcStatus getUnfolded (FILE *const vcf, char **const buff) {

    //int const buffSize = 30;
    size_t lineSize = 0;
    int done = 0;  //Set to one if the next line checked does not entail unfolding
    static char* queue = NULL;  //A queue to store the next line read in
    static int lineNum = 0;  
    char* buffer = NULL;  //The dynamic memory that will be linked to buf
    int valid_line = 0;  //Set to one if the line contains characters other then whitespace
    char* temp; //Used to point to the location of \r\n in the buffer

    VcStatus error;  //Initialize VcStatus with appropriate values
    error.code = OK;
    error.linefrom = lineNum;
    error.lineto = 0;

    //Special case for resetting getUnfolded()
    if (vcf == NULL){      
        lineNum = 0;
        if (queue != NULL) queue = NULL;
        error.linefrom = 0;
        error.lineto = 0;
        return error;
    }

    //Copies any string contained in queue from last time into buffer
    if (queue != NULL) {
        buffer = malloc (strlen (queue)+1);
        strcpy (buffer, queue);
        strcpy (queue, "");
    }

    //If the end of file has been reached, last line is returned.
    if (feof (vcf) != 0) {
        queue = NULL;
        lineNum += 1;
        if (buffer != NULL) {
          if (strcmp (buffer, "") != 0)*buff = buffer;
        }
        else *buff = NULL;
        return error;
    }

    while (done == 0) {

        //Gets a new line from the vcf file, and returns null if there is no more data to be returned
        getline (&queue, &lineSize, vcf);

        if (ferror(vcf) != 0) {
          error.code = IOERR;
          return error;
        }

        //Sets valid_line to 1 if the line read in contains any characters other then whitespace
        for (int i = 0; i < strlen (queue); i++){
            if (queue[i] != '\r' && queue[i] != '\n' && queue[i] != ' ' && queue[i] != '\t') valid_line = 1;
        }

        if (feof (vcf) && valid_line == 0) {
            queue = NULL;
            break;
        }        

        if (valid_line == 1){
            //Finds the 'internet standard' newline and replaces it with a null terminator
            temp = strstr (queue, "\r\n");
            if (temp != NULL) strcpy (temp, "\0");

            //Sets the buffer equal to contents of queue and resets queue if buffer is empty
            if (buffer == NULL) {

                buffer = malloc (strlen (queue)+1);
                lineNum = lineNum + 1;          
                strcpy (buffer, queue);
                strcpy (queue, "");

            //Checks for leading whitespace to indicate a folded line, and unfolds
            }else if (queue [0] == ' ' || queue [0] == '\t') {

                lineNum = lineNum + 1;
                buffer = realloc (buffer, strlen (buffer)+strlen (queue)+2);
                strcat (buffer, queue+1);
                strcpy (queue, "");

            //If both conditions above are false, buffer contains the next valid line
            }else{

                error.lineto = lineNum;
                lineNum += 1;
                done = 1;

            }
        }
    }

    *buff = buffer;

    return error;

}

...以及向其发送测试数据的虚拟函数：

int main () {

    FILE* fp = fopen ("test.vcf", "r");

    char * buff;

    getUnfolded (fp, &buff);

}

test.vcf 文件实际上只是一个简单的文本文件

任何帮助都会很棒。

Answer 1

您使用的 valgrind 版本已过时，因此它不会抑制正确的输出。这些错误在 suse 上仍然存在，只是因为它们在系统代码中而被抑制。

您需要手动安装最新版本的 valgrind

这是我使用的论坛帖子

http://ubuntuforums。 org/showthread.php?t=1608001