title: Valgrind on Basic Qt Application: Reports Masive Leaks
body: <p>So I wanted to see what would happen to a basic Qt4 Application compiled from a simple Makefile when run through Valgrind. What would be causing these leaks? I am deleting any dynamically allocated objects on my end. Also when exiting the program I only click on the close (X) up in the upper right corner. Do GUI libs just not <em>"free()"</em> any of the memory they <em>malloc()'d</em>?</p>
  
  <p>The Makefile reduced from qmake command is:</p>
  
  <pre><code>####### Compiler, tools and options
  
  CXX           = g++
  CXXFLAGS      = -pipe -O2 -Wall -W
  LIBS_INCLUDE  = ${HOME}
  INCPATH       = -I$(LIBS_INCLUDE)/QtSDK/Desktop/Qt/473/gcc/mkspecs/default \
                  -I. \
                  -I$(LIBS_INCLUDE)/QtSDK/Desktop/Qt/473/gcc/include/QtCore \
                  -I$(LIBS_INCLUDE)/QtSDK/Desktop/Qt/473/gcc/include/QtGui \
                  -I$(LIBS_INCLUDE)/QtSDK/Desktop/Qt/473/gcc/include 
  LINK          = g++
  LFLAGS        = -Wl,-O1 -Wl,-rpath,$(LIBS_INCLUDE)/QtSDK/Desktop/Qt/473/gcc/lib
  LIBS          = $(SUBLIBS)  -L$(LIBS_INCLUDE)/QtSDK/Desktop/Qt/473/gcc/lib -lQtGui -lQtCore -lpthread
  QMAKE         = $(LIBS_INCLUDE)/QtSDK/Desktop/Qt/473/gcc/bin/qmake
  OBJECTS_DIR   = ./
  SOURCES       = main.cpp
  OBJECTS       = main.o
  QMAKE_TARGET  = Main
  TARGET        = Main
  
  ####### Build rules
  first: all
  
  all: $(TARGET)
  
  $(TARGET):  $(OBJECTS)
          $(LINK) $(LFLAGS) -o $(TARGET) $(OBJECTS) $(OBJCOMP) $(LIBS)
  
  ####### Compile
  
  main.o: main.cpp
          $(CXX) -c $(CXXFLAGS) $(INCPATH) -o main.o main.cpp
  </code></pre>
  
  <p>The only source code is:</p>
  
  <pre><code>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 = new QPushButton(
          QApplication::translate( "childwidget", "Press me"), &amp;window );
      button-&gt;move( 100, 100 );
      button-&gt;show( );
      delete button;
      return app.exec();
  }
  </code></pre>
  
  <p>When run through valgrind I get the following (Removed Large Portion In Middle):</p>
  
  <pre><code>==3836== Memcheck, a memory error detector
  ==3836== Copyright (C) 2002-2009, and GNU GPL'd, by Julian Seward et al.
  ==3836== Using Valgrind-3.5.0 and LibVEX; rerun with -h for copyright info
  ==3836== Command: ./Main
  ==3836== 
  Xlib:  extension "RANDR" missing on display ":0.0".
  ==3836== 
  ==3836== HEAP SUMMARY:
  ==3836==     in use at exit: 924,383 bytes in 8,679 blocks
  ==3836==   total heap usage: 37,234 allocs, 28,555 frees, 4,314,180 bytes allocated
  ==3836== 
  ==3836== 1 bytes in 1 blocks are possibly lost in loss record 1 of 4,534
  ==3836==    at 0x400677E: malloc (vg_replace_malloc.c:195)
  ==3836==    by 0xA1DFA4: g_malloc (in /lib/libglib-2.0.so.0.2600.0)
  ==3836==    by 0xA37F29: g_strdup (in /lib/libglib-2.0.so.0.2600.0)
  ==3836==    by 0xB2A6FA: g_param_spec_string (in /lib/libgobject-2.0.so.0.2600.0)
  ==3836==    by 0x41F36473: ??? (in /usr/lib/libgtk-x11-2.0.so.0.2200.0)
  ==3836==    by 0xB3D237: g_type_class_ref (in /lib/libgobject-2.0.so.0.2600.0)
  ==3836==    by 0xB20B38: g_object_newv (in /lib/libgobject-2.0.so.0.2600.0)
  ==3836==    by 0xB212EF: g_object_new (in /lib/libgobject-2.0.so.0.2600.0)
  ==3836==    by 0x41F34857: gtk_settings_get_for_screen (in /usr/lib/libgtk-x11-2.0.so.0.2200.0)
  ==3836==    by 0x41ED0CB6: ??? (in /usr/lib/libgtk-x11-2.0.so.0.2200.0)
  ==3836==    by 0xB377C7: g_cclosure_marshal_VOID__OBJECT (in /lib/libgobject-2.0.so.0.2600.0)
  ==3836==    by 0xB1ABE2: g_closure_invoke (in /lib/libgobject-2.0.so.0.2600.0)
  ==3836== 
  ...
  ==3836== 
  ==3836== 23,048 bytes in 1 blocks are possibly lost in loss record 4,531 of 4,534
  ==3836==    at 0x400677E: malloc (vg_replace_malloc.c:195)
  ==3836==    by 0x16F42D: ??? (in /usr/lib/libfreetype.so.6.6.0)
  ==3836==    by 0x17400B: ft_mem_qalloc (in /usr/lib/libfreetype.so.6.6.0)
  ==3836==    by 0x174063: ft_mem_alloc (in /usr/lib/libfreetype.so.6.6.0)
  ==3836==    by 0x174508: ft_mem_qrealloc (in /usr/lib/libfreetype.so.6.6.0)
  ==3836==    by 0x17457F: ft_mem_realloc (in /usr/lib/libfreetype.so.6.6.0)
  ==3836==    by 0x1A2E52: ??? (in /usr/lib/libfreetype.so.6.6.0)
  ==3836==    by 0x1A709B: ??? (in /usr/lib/libfreetype.so.6.6.0)
  ==3836==    by 0x180338: ??? (in /usr/lib/libfreetype.so.6.6.0)
  ==3836==    by 0x175B5D: ??? (in /usr/lib/libfreetype.so.6.6.0)
  ==3836==    by 0x1780B0: FT_Open_Face (in /usr/lib/libfreetype.so.6.6.0)
  ==3836==    by 0x1791FF: FT_New_Face (in /usr/lib/libfreetype.so.6.6.0)
  ==3836== 
  ==3836== 53,244 bytes in 29 blocks are possibly lost in loss record 4,534 of 4,534
  ==3836==    at 0x400677E: malloc (vg_replace_malloc.c:195)
  ==3836==    by 0xA1DFA4: g_malloc (in /lib/libglib-2.0.so.0.2600.0)
  ==3836==    by 0xA36050: g_slice_alloc (in /lib/libglib-2.0.so.0.2600.0)
  ==3836==    by 0xA36315: g_slice_alloc0 (in /lib/libglib-2.0.so.0.2600.0)
  ==3836==    by 0xB40077: g_type_create_instance (in /lib/libgobject-2.0.so.0.2600.0)
  ==3836==    by 0xB1CE35: ??? (in /lib/libgobject-2.0.so.0.2600.0)
  ==3836==    by 0xB205C6: g_object_newv (in /lib/libgobject-2.0.so.0.2600.0)
  ==3836==    by 0xB212EF: g_object_new (in /lib/libgobject-2.0.so.0.2600.0)
  ==3836==    by 0x54B8FA3: ??? (in /usr/lib/gtk-2.0/2.10.0/engines/libclearlooks.so)
  ==3836==    by 0x41F0CDDD: ??? (in /usr/lib/libgtk-x11-2.0.so.0.2200.0)
  ==3836==    by 0x41F11C24: gtk_rc_get_style (in /usr/lib/libgtk-x11-2.0.so.0.2200.0)
  ==3836==    by 0x4200A81F: ??? (in /usr/lib/libgtk-x11-2.0.so.0.2200.0)
  ==3836== 
  ==3836== LEAK SUMMARY:
  ==3836==    definitely lost: 1,912 bytes in 7 blocks
  ==3836==    indirectly lost: 5,060 bytes in 250 blocks
  ==3836==      possibly lost: 491,358 bytes in 2,893 blocks
  ==3836==    still reachable: 426,053 bytes in 5,529 blocks
  ==3836==         suppressed: 0 bytes in 0 blocks
  ==3836== Reachable blocks (those to which a pointer was found) are not shown.
  ==3836== To see them, rerun with: --leak-check=full --show-reachable=yes
  ==3836== 
  ==3836== For counts of detected and suppressed errors, rerun with: -v
  ==3836== ERROR SUMMARY: 1336 errors from 1336 contexts (suppressed: 114 from 11)
  </code></pre>