尽管-g标志，Valgrind仍不显示行号（在Ubuntu 11.10 / VirtualBox上）

我正在关注“艰难学习C”，特别是关于Valgrind的章节。本章为您提供一个故意错误的程序，以显示Valgrind的工作方式。

当我在Valgrind下运行该练习时，在堆栈跟踪中没有得到行号，只是出现了“（在main以下）”错误。

我肯定在编译-g标志。

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 VM中使用Ubuntu 11.10。

感谢您的任何帮助。

更新资料

看来，如果我从中调用函数，main()并且该函数包含错误（例如，未初始化的变量），那么我确实可以找到该函数在其中被调用的位置main()。但是，其中的错误main()仍然不确定。有关示例，请参见此粘贴。

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

根据此消息，您应该这样运行./ex4：

valgrind --track-origins=yes ./ex4

为了避免Valgrind无法找到调试信息的某些问题，可以使用静态链接：

gcc -static -g  -o ex4  ex4.c 

Valgrind的输出将包含以下消息Uninitialised value was created by a stack allocation：

==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)

档案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堆栈框架（函数），但不打印变量名称。

在VirtualBox下运行Linux对Valgrind无效。

我也正在使用该-g标志进行编译，但仍未获得行号。删除.dSYM我的应用程序的目录，并使用该--dsymutil=yes选项运行valgrind之后，我终于得到了行号。

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软件包。

尝试gcc而不是cc

cc不提供行号，但是gcc可以提供

您应该使用“ -g”进行编译。gcc -g test.c -o测试然后valgrind --track-origins = yes --leak-check = full ./test

请注意，使用--dsymutil = yes解决方案运行valgrind仅适用于Mac OSX。

根据文档：

- dsymutil = NO | YES [无]在Mac OS X上运行Valgrind的时，此选项才相关

Mac OS X使用延迟的调试信息（debuginfo）链接方案。当包含debuginfo的目标文件链接到.dylib或可执行文件时，debuginfo不会复制到最终文件中。相反，必须通过在可执行文件或.dylib上运行dsymutil（系统提供的实用程序）来手动链接debuginfo。生成的组合debuginfo放在可执行文件或.dylib旁边的目录中，但扩展名为.dSYM。

我追逐了这个问题，其他答案都没有奏效。我的输出显示正确的符号，但是行号不存在。

在我的情况下，这是由于所讨论的库使用的是.zdebug压缩行号信息，而我使用的valgrind版本太旧了，还没有所需的补丁[0]。

解决方案是将valgrind升级到最新版本。

[0] https://bugs.kde.org/show_bug.cgi?id=303877