valgrind / callgrind可以在发布的可执行C ++程序上工作吗？

Question

I understand that valgrind can call memcheck to perform memory leak check, and in this case the compiled C++ executable program must contain debug information. Then, if I want to use valgrind/callgrind to perform profiling, must the executable contain debug information? I have run a small test, and it seems that valgrind/callgrind can work on release executable programs without debug information. Can anyone confirm it?

Answer 1

From Official Valgrind documentation link, following information can be found:

2.2. Getting started

First off, consider whether it might be beneficial to recompile your application and supporting libraries with debugging info enabled (the -g option) .

Without debugging info , the best Valgrind tools will be able to do is guess which function a particular piece of code belongs to, which makes both error messages and profiling output nearly useless . With -g, you'll get messages which point directly to the relevant source code lines.

Another option you might like to consider, if you are working with C++, is -fno-inline. That makes it easier to see the function-call chain, which can help reduce confusion when navigating around large C++ apps. For example, debugging OpenOffice.org with Memcheck is a bit easier when using this option. You don't have to do this, but doing so helps Valgrind produce more accurate and less confusing error reports. Chances are you're set up like this already, if you intended to debug your program with GNU GDB, or some other debug.

Hence the recommended step is to recompile your program with -g option to get maximum information from the Valgrind.

Answer 2

According to the valgrind manual:

http://valgrind.org/docs/manual/manual-core.html

If you are planning to use Memcheck: On rare occasions, compiler optimisations (at -O2 and above, and sometimes -O1) have been observed to generate code which fools Memcheck into wrongly reporting uninitialised value errors, or missing uninitialised value errors. We have looked in detail into fixing this, and unfortunately the result is that doing so would give a further significant slowdown in what is already a slow tool. So the best solution is to turn off optimisation altogether. Since this often makes things unmanageably slow, a reasonable compromise is to use -O. This gets you the majority of the benefits of higher optimisation levels whilst keeping relatively small the chances of false positives or false negatives from Memcheck. Also, you should compile your code with -Wall because it can identify some or all of the problems that Valgrind can miss at the higher optimisation levels. (Using -Wall is also a good idea in general.) All other tools (as far as we know) are unaffected by optimisation level, and for profiling tools like Cachegrind it is better to compile your program at its normal optimisation level.