valgrind says my code is wrong, but I don't see where ...

django.Reinhard

Hi,

please apologize for not using the right technical terms.
This is the output of valgrind:

==192232==  Uninitialised value was created by a heap allocation
==192232==    at 0x483877F: malloc (vg_replace_malloc.c:307)
==192232==    by 0x611782C: QArrayData::allocate(unsigned long, unsigned long, 
unsigned long, QFlags<QArrayData::AllocationOption>) (qarraydata.cpp:218)
==192232==    by 0x619AF58: allocate (qarraydata.h:225)
==192232==    by 0x619AF58: QString::reallocData(unsigned int, bool) 
(qstring.cpp:2371)
==192232==    by 0x619B057: QString::resize(int) (qstring.cpp:2288)
==192232==    by 0x619E972: QString::setUnicode(QChar const*, int) 
(qstring.cpp:5687)
==192232==    by 0x63846CA: QTextStream::readLineInto(QString*, long long) 
(qtextstream.cpp:1725)
==192232==    by 0x638498D: QTextStream::readLine(long long) (qtextstream.cpp:
1676)
==192232==    by 0x199941: LcProperties::processFile(QFile&) 
(lcproperties.cpp:124)
==192232==    by 0x198E35: LcProperties::LcProperties(QString const&) 
(lcproperties.cpp:14)
==192232==    by 0x18BEFB: GuiKernel::initialize(QLocale const&, DBHelper&) 
(guikernel.cpp:78)
==192232==    by 0x171791: Core::Core(QString const&, QString const&, QLocale 
const&, DBHelper&, QString const&) (core.cpp:21)
==192232==    by 0x189855: GuiCore::GuiCore(QString const&, QString const&, 
QLocale const&, DBHelper&, QString const&) (guicore.cpp:36)

guicore.cpp:36 is the initialization call of that singleton (GuiCore is the subclass of the singletons accessor/wrapper). That call exists once in the application. Exactly at main.cpp:64

GuiCore::setKernelCreator(new GuiKernelCreator());
GuiCore      appCore(iniFileName, "FalconView", curLocale, dbHelper);

First line creates a factory and adds it to the singleton.
Second line calls the initialization constructor (guicore.cpp:36)

GuiCore::GuiCore(const QString& iniFileName, const QString& appName, const 
QLocale& locale, DBHelper& dbAssist, const QString& groupID)
 : Core(iniFileName, appName, locale, dbAssist, groupID) {
  }

Second line is line 36 which valgrind blames.
Next step is core.cpp:21 - the singletons accessor wrapper base class:

Core::Core(const QString& iniFileName, const QString& appName, const QLocale& 
locale, DBHelper& dbAssist, const QString& group) {
  if (!kernel) {
     assert(kc);
     kernel = kc->kernel(iniFileName, appName, group);
     kernel->initialize(locale, dbAssist);
     }
  }

Line 21 is the call to initialize.
Explaining the constructor:

kc is the factory set at main.
kernel is the static pointer of the singleton

next blamed line is guikernel.cpp:78 - guikernel is the private class of the
singleton static part, which extends Kernel.

void GuiKernel::initialize(const QLocale& locale, DBHelper &dbAssist) {
  Kernel::initialize(locale, dbAssist);
  lcProps = new LcProperties(fileName);

last line is line 78

lcProps is a member pointer (initialized to 0 at constructor call).
fileName is a member of superclass (Kernel) set at initialization constructor
call from main

constructor of LcProperties is lcproperties.cpp:14

LcProperties::LcProperties(const QString& fileName)
 : curMap(nullptr)
 , fn(fileName) {
  QFile file(fileName);

  if (file.exists()) processFile(file);
  }

line 14 is the call to processFile, which is next blamed line
(lcproperties.cpp:124):

  if (file.open(QIODevice::ReadOnly | QIODevice::Text)) {
     QTextStream in(&file);
     QString line = in.readLine();

     while (!line.isNull()) {
           processLine(line);
           line = in.readLine();
           }
     file.close();
     }

line 124 is the call to QTextStream::readLine ...

Its a long way to here and now it dives into Qt code.
I expect the blamed error is in the above code parts, but I don't see it.

Christian Ehrlicher

Ignore it, imo valgrind is wrong on this problem inside Qt.

django.Reinhard

Thanks a lot!