Memory leak Detection using Valgrind

[joseph]

Hello

I am running my application on Open Suse10.2 and i am using "Valgrind"
to detect memory leaks in the program.

I want to know how to suppress the memory leaks created in the dynamically linked libraries,since i want to know precisely where my program is leaking rather than in the linked libraries.

Thank You,

[pdoria]

Hey Joseph

Did you put

CONFIG += debug

CONFIG += debug

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in your .pro file?

I also find using G_SLICE=always-malloc before the call to the program for debugging purposes. someting like this:

valgrind -v --leak-check=yes G_SLICE=always-malloc ./myapp

HTH,
Pedro.

[joseph]

When i run valgrind -v --leak-check=yes command, it gives me a very comprehensive list of memory leak errors mostly from the linked "LIBRARIES".I want to suppress these messages.I want to know only memory leaks caused in my code.
How to this suppress file?

[wysota]

You can use grep -v, if that's an option for you...

[momesana]

you suppress those warnings/errors by using suppress files. You best generate those with the command switch --gen-suppressions.

valgrind --tool=memcheck --leak-check=yes --gen-suppressions=yes ./yourapplication

valgrind --tool=memcheck --leak-check=yes --gen-suppressions=yes ./yourapplication

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You then copy paste the suppressions into a file, give them appropriate names and use that file with the --suppressions switch when debugging your application.
A suppress statement may look like this:

{
  Qt-Gui-getpwuid
   Memcheck:Leak
   fun:malloc
   obj:/lib/libc-2.6.1.so
   fun:__nss_database_lookup
   obj:*
   obj:*
   fun:getpwuid_r
   obj:/usr/lib/qt4/libQtGui.so.4.3.2
   obj:/usr/lib/qt4/libQtGui.so.4.3.2
   fun:_SmcProcessMessage
   fun:IceProcessMessages
   obj:/usr/lib/qt4/libQtGui.so.4.3.2
   obj:/usr/lib/qt4/libQtGui.so.4.3.2
}

{
  Qt-Gui-getpwuid
   Memcheck:Leak
   fun:malloc
   obj:/lib/libc-2.6.1.so
   fun:__nss_database_lookup
   obj:*
   obj:*
   fun:getpwuid_r
   obj:/usr/lib/qt4/libQtGui.so.4.3.2
   obj:/usr/lib/qt4/libQtGui.so.4.3.2
   fun:_SmcProcessMessage
   fun:IceProcessMessages
   obj:/usr/lib/qt4/libQtGui.so.4.3.2
   obj:/usr/lib/qt4/libQtGui.so.4.3.2
}

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You then call your application with the suppress file provided as an argument:

valgrind --tool=memcheck --leak-check=yes --suppressions=suppressfilexy.supp  ./yourapplication

valgrind --tool=memcheck --leak-check=yes --suppressions=suppressfilexy.supp  ./yourapplication

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Be careful not to put error-reports belonging to your applictations code into the suppress file.