Limit --memcheck To Your Own Code

Question

Lets say I am using a library that uses glibc. When I exit the program while running it through Valgrind all sorts of memory leaks are detected by Valgrind. I am 100% sure that none of the leaks are explicitly related to my few lines of code I just wrote. Is there a way to suppress leaks from other libraries, and limit the leak detection to your immediate code?

For example:

valgrind --tool=memcheck --leak-check=full --leak-resolution=high \
    --log-file=vgdump ./Main

Where the executable was built from the following source:

// Include header files for application components.
#include <QtGui>

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    QWidget window;
    window.resize( 320,240 );
    window.setWindowTitle(
        QApplication::translate( "toplevel", "Top-level Widget" ) );
    window.show( );

    QPushButton button(                   
        QApplication::translate( "childwidget", "Press me"), &window );
    button.move( 100, 100 );
    button.show( );
    int status = app.exec();
    return status;
}

Has a log-file that reports the following (large portions removed):

   ==12803== Memcheck, a memory error detector
   ==12803== Copyright (C) 2002-2009, and GNU GPL'd, by Julian Seward et al.
   ==12803== Using Valgrind-3.5.0 and LibVEX; rerun with -h for copyright info
   ==12803== Command: ./Main
   ==12803== Parent PID: 12700
   ==12803==
   ==12803==
   ==12803== HEAP SUMMARY:
   ==12803==     in use at exit: 937,411 bytes in 8,741 blocks
   ==12803==   total heap usage: 38,227 allocs, 29,486 frees, 5,237,254 bytes allocated
   ==12803==
   ==12803== 1 bytes in 1 blocks are possibly lost in loss record 1 of 4,557
   ==12803==    at 0x402577E: malloc (vg_replace_malloc.c:195)
   ==12803==    by 0xA1DFA4: g_malloc (in /lib/libglib-2.0.so.0.2600.0)
   ==12803==    by 0xA37F29: g_strdup (in /lib/libglib-2.0.so.0.2600.0)
   ==12803==    by 0xB2A6FA: g_param_spec_string (in /lib/libgobject-2.0.so.0.2600.0)
   ==12803==    by 0x41F36473: ??? (in /usr/lib/libgtk-x11-2.0.so.0.2200.0)
   ==12803==    by 0xB3D237: g_type_class_ref (in /lib/libgobject-2.0.so.0.2600.0)
   ==12803==    by 0xB20B38: g_object_newv (in /lib/libgobject-2.0.so.0.2600.0)
   ==12803==    by 0xB212EF: g_object_new (in /lib/libgobject-2.0.so.0.2600.0)
   ==12803==    by 0x41F34857: gtk_settings_get_for_screen (in /usr/lib/libgtk-x11-2.0.so.0.2200.0)
   ==12803==    by 0x41ED0CB6: ??? (in /usr/lib/libgtk-x11-2.0.so.0.2200.0)
   ==12803==    by 0xB377C7: g_cclosure_marshal_VOID__OBJECT (in /lib/libgobject-2.0.so.0.2600.0)
   ==12803==    by 0xB1ABE2: g_closure_invoke (in /lib/libgobject-2.0.so.0.2600.0)
    ...

    ==12803== 53,244 bytes in 29 blocks are possibly lost in loss record 4,557 of 4,557
    ==12803==    at 0x402577E: malloc (vg_replace_malloc.c:195)
    ==12803==    by 0xA1DFA4: g_malloc (in /lib/libglib-2.0.so.0.2600.0)
    ==12803==    by 0xA36050: g_slice_alloc (in /lib/libglib-2.0.so.0.2600.0)
    ==12803==    by 0xA36315: g_slice_alloc0 (in /lib/libglib-2.0.so.0.2600.0)
    ==12803==    by 0xB40077: g_type_create_instance (in /lib/libgobject-2.0.so.0.2600.0)
    ==12803==    by 0xB1CE35: ??? (in /lib/libgobject-2.0.so.0.2600.0)
    ==12803==    by 0xB205C6: g_object_newv (in /lib/libgobject-2.0.so.0.2600.0)
    ==12803==    by 0xB212EF: g_object_new (in /lib/libgobject-2.0.so.0.2600.0)
    ==12803==    by 0x6180FA3: ??? (in /usr/lib/gtk-2.0/2.10.0/engines/libclearlooks.so)
    ==12803==    by 0x41F0CDDD: ??? (in /usr/lib/libgtk-x11-2.0.so.0.2200.0)
    ==12803==    by 0x41F11C24: gtk_rc_get_style (in /usr/lib/libgtk-x11-2.0.so.0.2200.0)
    ==12803==    by 0x4200A81F: ??? (in /usr/lib/libgtk-x11-2.0.so.0.2200.0)
    ==12803==
    ==12803== LEAK SUMMARY:
    ==12803==    definitely lost: 2,296 bytes in 8 blocks
    ==12803==    indirectly lost: 7,720 bytes in 382 blocks
    ==12803==      possibly lost: 509,894 bytes in 2,908 blocks
    ==12803==    still reachable: 417,501 bytes in 5,443 blocks
    ==12803==         suppressed: 0 bytes in 0 blocks
    ==12803== Reachable blocks (those to which a pointer was found) are not shown.
    ==12803== To see them, rerun with: --leak-check=full --show-reachable=yes
    ==12803==
    ==12803== For counts of detected and suppressed errors, rerun with: -v
    ==12803== ERROR SUMMARY: 1364 errors from 1364 contexts (suppressed: 122 from 11)

Answer 1

To ignore Leak errors in all shared libraries under any lib directory (/lib, /lib64, /usr/lib, /usr/lib64, ...), put this in a file and pass it to valgrind with --suppressions=*FILENAME*:

{
   ignore_unversioned_libs
   Memcheck:Leak
   ...
   obj:*/lib*/lib*.so
}
{
   ignore_versioned_libs
   Memcheck:Leak
   ...
   obj:*/lib*/lib*.so.*
}

This will probably suffice to limit memcheck reporting to your own code only. However, beware that this will ignore errors caused by any callbacks you wrote that were invoked by the libraries. Catching errors in those callbacks could almost be done with:

{
   ignore_unversioned_libs
   Memcheck:Leak
   obj:*/lib*/lib*.so
   ...
   obj:*/lib*/lib*.so
}
{
   ignore_versioned_libs
   Memcheck:Leak
   obj:*/lib*/lib*.so.*
   ...
   obj:*/lib*/lib*.so.*
}

... but this reveals errors in calls by a library that use the Valgrind malloc. Since valgrind malloc is injected directly into the program text -- not loaded as a dynamic library -- it appears in the stack the same way as your own code does. This allows Valgrind to track the allocations, but also makes it harder to do exactly what you have asked.

FYI: I am using valgrind 3.5.

The above is an excerpt of an answer to an older, slightly different question that is asked in the body text of this question (so title is a little insufficient):

• Is it possible to make valgrind ignore certain libraries?

Answer 2

Look up the topic of suppressions at the Valgrind web site; you want to suppress errors from the third party library.