我关注的是“艰难地学习C语言”,特别是the chapter on Valgrind。本章故意给出一个错误的程序来说明Valgrind是如何工作的。
当我在Valgrind下运行练习时,我在堆栈跟踪中没有得到行号,只是‘(在main下面)’表示错误。
我绝对是用-g标志编译的。
我的Valgrind输出如下:
djb@twin:~/projects/Learning/C$ valgrind ./ex4
==5190== Memcheck, a memory error detector
==5190== Copyright (C) 2002-2010, and GNU GPL'd, by Julian Seward et al.
==5190== Using Valgrind-3.6.1-Debian and LibVEX; rerun with -h for copyright info
==5190== Command: ./ex4
==5190==
==5190== Use of uninitialised value of size 4
==5190== at 0x4078B2B: _itoa_word (_itoa.c:195)
==5190== by 0x407CE55: vfprintf (vfprintf.c:1619)
==5190== by 0x40831DE: printf (printf.c:35)
==5190== by 0x4052112: (below main) (libc-start.c:226)
==5190==
==5190== Conditional jump or move depends on uninitialised value(s)
==5190== at 0x4078B33: _itoa_word (_itoa.c:195)
==5190== by 0x407CE55: vfprintf (vfprintf.c:1619)
==5190== by 0x40831DE: printf (printf.c:35)
==5190== by 0x4052112: (below main) (libc-start.c:226)
==5190==
==5190== Conditional jump or move depends on uninitialised value(s)
==5190== at 0x407CC10: vfprintf (vfprintf.c:1619)
==5190== by 0x40831DE: printf (printf.c:35)
==5190== by 0x4052112: (below main) (libc-start.c:226)
==5190==
==5190== Conditional jump or move depends on uninitialised value(s)
==5190== at 0x407C742: vfprintf (vfprintf.c:1619)
==5190== by 0x40831DE: printf (printf.c:35)
==5190== by 0x4052112: (below main) (libc-start.c:226)
==5190==
I am 0 years old.
I am 68882420 inches tall.
==5190==
==5190== HEAP SUMMARY:
==5190== in use at exit: 0 bytes in 0 blocks
==5190== total heap usage: 0 allocs, 0 frees, 0 bytes allocated
==5190==
==5190== All heap blocks were freed -- no leaks are possible
==5190==
==5190== For counts of detected and suppressed errors, rerun with: -v
==5190== Use --track-origins=yes to see where uninitialised values come from
==5190== ERROR SUMMARY: 22 errors from 4 contexts (suppressed: 11 from 6)
我在VirtualBox虚拟机中使用Ubuntu11.10。
谢谢你的帮助。
更新
似乎如果我从main()
调用一个函数,并且该函数包含一个错误(例如,一个未初始化的变量),那么我确实可以跟踪到在main()
中调用该函数的位置。但是,main()
中的错误仍然未指明。有关示例,请参阅this paste。
发布于 2012-03-05 22:13:52
您在问题中提供的输出包含以下行:
==5190== Use --track-origins=yes to see where uninitialised values come from
根据这条消息,您应该像这样运行./ex4
:
valgrind --track-origins=yes ./ex4
为了避免Valgrind找不到调试信息的问题,您可以使用静态链接:
gcc -static -g -o ex4 ex4.c
Valgrind的输出将包含像Uninitialised value was created by a stack allocation
这样的消息
==17673== Memcheck, a memory error detector
==17673== Copyright (C) 2002-2011, and GNU GPL'd, by Julian Seward et al.
==17673== Using Valgrind-3.7.0 and LibVEX; rerun with -h for copyright info
==17673== Command: ./ex4
...
==17673== Use of uninitialised value of size 4
==17673== at 0x805CA7B: _itoa_word (in /home/user/ex4)
==17673== by 0x8049D5F: printf (in /home/user/ex4)
==17673== by 0x8048ECD: main (ex4.c:8)
==17673== Uninitialised value was created by a stack allocation
==17673== at 0x8048EFA: bad_function (ex4.c:17)
...
==17673== Use of uninitialised value of size 4
==17673== at 0x805CA7B: _itoa_word (in /home/user/ex4)
==17673== by 0x8049D5F: printf (in /home/user/ex4)
==17673== by 0x80490BE: (below main) (in /home/user/ex4)
==17673== Uninitialised value was created by a stack allocation
==17673== at 0x8048EBE: main (ex4.c:4)
...
I am -1094375076 years old.
...
I am -1094369310 inches tall.
...
==17673==
==17673== HEAP SUMMARY:
==17673== in use at exit: 0 bytes in 0 blocks
==17673== total heap usage: 0 allocs, 0 frees, 0 bytes allocated
==17673==
==17673== All heap blocks were freed -- no leaks are possible
==17673==
==17673== For counts of detected and suppressed errors, rerun with: -v
==17673== ERROR SUMMARY: 83 errors from 21 contexts (suppressed: 0 from 0)
文件ex4.c
1 #include <stdio.h>
2
3 int main()
4 {
5 int age = 10;
6 int height;
7
8 bad_function();
9
10 printf("I am %d years old.\n");
11 printf("I am %d inches tall.\n", height);
12
13 return 0;
14 }
15
16 int bad_function()
17 {
18 int x;
19 printf("%d\n", x);
20 }
Valgrind的输出并不理想。它标识包含未初始化变量的栈帧(函数),但不打印变量的名称。
在VirtualBox下运行Linux对Valgrind没有影响。
发布于 2013-07-23 07:20:12
我也在使用-g
标志进行编译,但是仍然没有得到行号。在删除我的应用程序的.dSYM
目录,并使用--dsymutil=yes
选项运行valgrind之后,我终于得到了行号。
发布于 2012-02-26 06:50:20
在许多发行版中,glibc的默认版本不包含调试符号。
尝试安装libc6-dbg包。
https://stackoverflow.com/questions/9321385
复制相似问题