我有一个C语言程序,它在命令行上使用标志和文件。为了处理这些文件,我将它们放在一个动态分配的char**
类型数组中,就是在处理这个数组时Valgrind报告了问题。
==14389== Memcheck, a memory error detector
==14389== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==14389== Using Valgrind-3.13.0 and LibVEX; rerun with -h for copyright info
==14389== Command: ./main
==14389==
==14389== Conditional jump or move depends on uninitialised value(s)
==14389== at 0x4838931: free (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14389== by 0x10931B: Options_append_filename (main.c:53)
==14389== by 0x1094B9: parse_cmdline (main.c:85)
==14389== by 0x109544: main (main.c:98)
==14389==
==14389== Invalid write of size 8
==14389== at 0x10934A: Options_append_filename (main.c:54)
==14389== by 0x1094B9: parse_cmdline (main.c:85)
==14389== by 0x109544: main (main.c:98)
==14389== Address 0x4a53090 is 0 bytes inside a block of size 1 alloc'd
==14389== at 0x483998B: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14389== by 0x1092DA: Options_append_filename (main.c:44)
==14389== by 0x1094B9: parse_cmdline (main.c:85)
==14389== by 0x109544: main (main.c:98)
==14389==
==14389== Use of uninitialised value of size 8
==14389== at 0x483A9B8: strcpy (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14389== by 0x109373: Options_append_filename (main.c:55)
==14389== by 0x1094B9: parse_cmdline (main.c:85)
==14389== by 0x109544: main (main.c:98)
==14389==
==14389== Use of uninitialised value of size 8
==14389== at 0x483A9C7: strcpy (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14389== by 0x109373: Options_append_filename (main.c:55)
==14389== by 0x1094B9: parse_cmdline (main.c:85)
==14389== by 0x109544: main (main.c:98)
==14389==
==14389== Conditional jump or move depends on uninitialised value(s)
==14389== at 0x483A9D9: strcpy (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14389== by 0x109373: Options_append_filename (main.c:55)
==14389== by 0x1094B9: parse_cmdline (main.c:85)
==14389== by 0x109544: main (main.c:98)
==14389==
==14389== Conditional jump or move depends on uninitialised value(s)
==14389== at 0x483A9E3: strcpy (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14389== by 0x109373: Options_append_filename (main.c:55)
==14389== by 0x1094B9: parse_cmdline (main.c:85)
==14389== by 0x109544: main (main.c:98)
==14389==
==14389== Conditional jump or move depends on uninitialised value(s)
==14389== at 0x483A9E5: strcpy (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14389== by 0x109373: Options_append_filename (main.c:55)
==14389== by 0x1094B9: parse_cmdline (main.c:85)
==14389== by 0x109544: main (main.c:98)
==14389==
==14389== Conditional jump or move depends on uninitialised value(s)
==14389== at 0x483A9F4: strcpy (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14389== by 0x109373: Options_append_filename (main.c:55)
==14389== by 0x1094B9: parse_cmdline (main.c:85)
==14389== by 0x109544: main (main.c:98)
==14389==
==14389== Invalid write of size 8
==14389== at 0x10938D: Options_append_filename (main.c:56)
==14389== by 0x1094B9: parse_cmdline (main.c:85)
==14389== by 0x109544: main (main.c:98)
==14389== Address 0x4a53098 is 7 bytes after a block of size 1 alloc'd
==14389== at 0x483998B: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14389== by 0x1092DA: Options_append_filename (main.c:44)
==14389== by 0x1094B9: parse_cmdline (main.c:85)
==14389== by 0x109544: main (main.c:98)
==14389==
==14389== Conditional jump or move depends on uninitialised value(s)
==14389== at 0x1095AE: main (main.c:113)
==14389==
==14389== Invalid read of size 8
==14389== at 0x1095A8: main (main.c:113)
==14389== Address 0x4a53098 is 7 bytes after a block of size 1 alloc'd
==14389== at 0x483998B: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14389== by 0x1092DA: Options_append_filename (main.c:44)
==14389== by 0x1094B9: parse_cmdline (main.c:85)
==14389== by 0x109544: main (main.c:98)
==14389==
==14389== Conditional jump or move depends on uninitialised value(s)
==14389== at 0x48C2F73: vfprintf (vfprintf.c:1638)
==14389== by 0x48CB995: printf (printf.c:33)
==14389== by 0x1095E2: main (main.c:117)
==14389==
==14389== Use of uninitialised value of size 8
==14389== at 0x483A852: strlen (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14389== by 0x48C431D: vfprintf (vfprintf.c:1638)
==14389== by 0x48CB995: printf (printf.c:33)
==14389== by 0x1095E2: main (main.c:117)
==14389==
==14389== Use of uninitialised value of size 8
==14389== at 0x483A864: strlen (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14389== by 0x48C431D: vfprintf (vfprintf.c:1638)
==14389== by 0x48CB995: printf (printf.c:33)
==14389== by 0x1095E2: main (main.c:117)
==14389==
==14389== Conditional jump or move depends on uninitialised value(s)
==14389== at 0x48F1993: _IO_file_xsputn@@GLIBC_2.2.5 (fileops.c:1224)
==14389== by 0x48C3018: vfprintf (vfprintf.c:1638)
==14389== by 0x48CB995: printf (printf.c:33)
==14389== by 0x1095E2: main (main.c:117)
==14389==
==14389== Use of uninitialised value of size 8
==14389== at 0x48F1995: _IO_file_xsputn@@GLIBC_2.2.5 (fileops.c:1226)
==14389== by 0x48C3018: vfprintf (vfprintf.c:1638)
==14389== by 0x48CB995: printf (printf.c:33)
==14389== by 0x1095E2: main (main.c:117)
==14389==
==14389== Conditional jump or move depends on uninitialised value(s)
==14389== at 0x48F19A6: _IO_file_xsputn@@GLIBC_2.2.5 (fileops.c:1224)
==14389== by 0x48C3018: vfprintf (vfprintf.c:1638)
==14389== by 0x48CB995: printf (printf.c:33)
==14389== by 0x1095E2: main (main.c:117)
==14389==
==14389== Use of uninitialised value of size 8
==14389== at 0x48F19A8: _IO_file_xsputn@@GLIBC_2.2.5 (fileops.c:1226)
==14389== by 0x48C3018: vfprintf (vfprintf.c:1638)
==14389== by 0x48CB995: printf (printf.c:33)
==14389== by 0x1095E2: main (main.c:117)
==14389==
==14389== Conditional jump or move depends on uninitialised value(s)
==14389== at 0x48F19D0: _IO_file_xsputn@@GLIBC_2.2.5 (fileops.c:1224)
==14389== by 0x48C3018: vfprintf (vfprintf.c:1638)
==14389== by 0x48CB995: printf (printf.c:33)
==14389== by 0x1095E2: main (main.c:117)
==14389==
==14389== Use of uninitialised value of size 8
==14389== at 0x48F19C4: _IO_file_xsputn@@GLIBC_2.2.5 (fileops.c:1226)
==14389== by 0x48C3018: vfprintf (vfprintf.c:1638)
==14389== by 0x48CB995: printf (printf.c:33)
==14389== by 0x1095E2: main (main.c:117)
==14389==
==14389== Conditional jump or move depends on uninitialised value(s)
==14389== at 0x483EA3F: mempcpy (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14389== by 0x48F1951: _IO_file_xsputn@@GLIBC_2.2.5 (fileops.c:1243)
==14389== by 0x48C3018: vfprintf (vfprintf.c:1638)
==14389== by 0x48CB995: printf (printf.c:33)
==14389== by 0x1095E2: main (main.c:117)
==14389==
==14389== Conditional jump or move depends on uninitialised value(s)
==14389== at 0x483EA57: mempcpy (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14389== by 0x48F1951: _IO_file_xsputn@@GLIBC_2.2.5 (fileops.c:1243)
==14389== by 0x48C3018: vfprintf (vfprintf.c:1638)
==14389== by 0x48CB995: printf (printf.c:33)
==14389== by 0x1095E2: main (main.c:117)
==14389==
==14389== Conditional jump or move depends on uninitialised value(s)
==14389== at 0x483EA5C: mempcpy (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14389== by 0x48F1951: _IO_file_xsputn@@GLIBC_2.2.5 (fileops.c:1243)
==14389== by 0x48C3018: vfprintf (vfprintf.c:1638)
==14389== by 0x48CB995: printf (printf.c:33)
==14389== by 0x1095E2: main (main.c:117)
==14389==
==14389== Use of uninitialised value of size 8
==14389== at 0x483EA70: mempcpy (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14389== by 0x48F1951: _IO_file_xsputn@@GLIBC_2.2.5 (fileops.c:1243)
==14389== by 0x48C3018: vfprintf (vfprintf.c:1638)
==14389== by 0x48CB995: printf (printf.c:33)
==14389== by 0x1095E2: main (main.c:117)
==14389==
==14389== Use of uninitialised value of size 8
==14389== at 0x483EA81: mempcpy (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14389== by 0x48F1951: _IO_file_xsputn@@GLIBC_2.2.5 (fileops.c:1243)
==14389== by 0x48C3018: vfprintf (vfprintf.c:1638)
==14389== by 0x48CB995: printf (printf.c:33)
==14389== by 0x1095E2: main (main.c:117)
==14389==
opts.files[0] is: './main'
==14389==
==14389== HEAP SUMMARY:
==14389== in use at exit: 8 bytes in 2 blocks
==14389== total heap usage: 4 allocs, 2 frees, 1,040 bytes allocated
==14389==
==14389== 1 bytes in 1 blocks are definitely lost in loss record 1 of 2
==14389== at 0x483998B: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14389== by 0x1092DA: Options_append_filename (main.c:44)
==14389== by 0x1094B9: parse_cmdline (main.c:85)
==14389== by 0x109544: main (main.c:98)
==14389==
==14389== 7 bytes in 1 blocks are definitely lost in loss record 2 of 2
==14389== at 0x483774F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14389== by 0x109349: Options_append_filename (main.c:54)
==14389== by 0x1094B9: parse_cmdline (main.c:85)
==14389== by 0x109544: main (main.c:98)
==14389==
==14389== LEAK SUMMARY:
==14389== definitely lost: 8 bytes in 2 blocks
==14389== indirectly lost: 0 bytes in 0 blocks
==14389== possibly lost: 0 bytes in 0 blocks
==14389== still reachable: 0 bytes in 0 blocks
==14389== suppressed: 0 bytes in 0 blocks
==14389==
==14389== For counts of detected and suppressed errors, rerun with: -v
==14389== Use --track-origins=yes to see where uninitialised values come from
==14389== ERROR SUMMARY: 48 errors from 27 contexts (suppressed: 0 from 0)
我已经尝试过使用数据初始化数组等方式进行操作。
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
typedef struct {
bool help_flag;
bool version_flag;
char **files;
} Options;
Options Options_new() {
Options opts;
opts.help_flag = false;
opts.version_flag = false;
opts.files = malloc(sizeof(NULL));
opts.files = NULL;
return opts;
}
void Options_cleanup_mem(Options *opts) {
int i = 0;
while (opts->files[i] != NULL)
i++;
for (int j = 0; j < i + 1; j++) {
free(opts->files[j]);
}
}
int Options_append_filename(Options *opts, char *filename) {
int num_files = 0;
char **tmp;
while (opts->files[num_files] != NULL)
num_files++;
tmp = realloc(opts->files, num_files + 1);
/* Handle case where realloc can't allocate memory */
if (tmp == NULL) {
return -1;
}
opts->files = tmp;
free(opts->files[num_files]);
opts->files[num_files] = malloc(strlen(filename) + 1);
strcpy(opts->files[num_files], filename);
opts->files[num_files + 1] = NULL;
return 0;
}
Options parse_cmdline(int argc, char **argv) {
Options opts = Options_new();
for (int a = 0; a < argc; a++) {
if (argv[a][0] == '-') {
char *longopt = argv[a];
if (!strcmp(longopt, "--help")) {
opts.help_flag = true;
} else if (!strcmp(longopt, "--version")) {
opts.version_flag = true;
} else {
fprintf(stderr, "Unkown option\n");
Options_cleanup_mem(&opts);
exit(1);
}
} else {
if (Options_append_filename(&opts, argv[a]) != 0) {
fprintf(stderr, "Error processing arguments\n");
Options_cleanup_mem(&opts);
}
}
}
return opts;
}
int main(int argc, char **argv) {
Options opts = parse_cmdline(argc, argv);
if (opts.help_flag) {
printf("Help message\n");
return 2;
}
if (opts.version_flag) {
printf("Version message\n");
return 2;
}
int i = 0;
while (opts.files[i] != NULL)
i++;
for (int a = 0; a < i; a++)
printf("opts.files[%d] is: '%s'\n", a, opts.files[a]);
return 0;
}