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QWizard: Replace another pointer table with char arrays

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Like in I53284066, the result of the SIGNALS() macro is handled in a switch
statement, while the other two character pointers in the struct are replaced
by character arrays of 'maximum occurring size'. If this looks wasteful, it
really isn't:

 Linux AMD64 GCC 4.9-pre stripped -O2 effects:
     text size: -280B
     data size: -160B
     relocs:     -21

When adding longer strings, compilers will warn, so this doesn't hurt
maintainability, either.

Change-Id: I5ac1cdffd8ac0ea0a1ede1ea4edcc6d3e22dcaa2
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
This commit is contained in:
Marc Mutz 2013-10-01 00:21:52 +02:00 committed by The Qt Project
parent 132e812556
commit 432674d787
1 changed files with 34 additions and 15 deletions
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49
src/widgets/dialogs/qwizard.cpp
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@ -129,22 +129,41 @@ static bool objectInheritsXAndXIsCloserThanY(const QObject *object, const QByteA
return false; return false;
} }
const int NFallbackDefaultProperties = 7;
const struct { const struct {
const char *className; const char className[16];
const char *property; const char property[13];
const char *changedSignal; } fallbackProperties[] = {
} fallbackProperties[NFallbackDefaultProperties] = {
// If you modify this list, make sure to update the documentation (and the auto test) // If you modify this list, make sure to update the documentation (and the auto test)
{ "QAbstractButton", "checked", SIGNAL(toggled(bool)) }, { "QAbstractButton", "checked" },
{ "QAbstractSlider", "value", SIGNAL(valueChanged(int)) }, { "QAbstractSlider", "value" },
{ "QComboBox", "currentIndex", SIGNAL(currentIndexChanged(int)) }, { "QComboBox", "currentIndex" },
{ "QDateTimeEdit", "dateTime", SIGNAL(dateTimeChanged(QDateTime)) }, { "QDateTimeEdit", "dateTime" },
{ "QLineEdit", "text", SIGNAL(textChanged(QString)) }, { "QLineEdit", "text" },
{ "QListWidget", "currentRow", SIGNAL(currentRowChanged(int)) }, { "QListWidget", "currentRow" },
{ "QSpinBox", "value", SIGNAL(valueChanged(int)) } { "QSpinBox", "value" },
}; };
const size_t NFallbackDefaultProperties = sizeof fallbackProperties / sizeof *fallbackProperties;
static const char *changed_signal(int which)
{
// since it might expand to a runtime function call (to
// qFlagLocations()), we cannot store the result of SIGNAL() in a
// character array and expect it to be statically initialized. To
// avoid the relocations caused by a char pointer table, use a
// switch statement:
switch (which) {
case 0: return SIGNAL(toggled(bool));
case 1: return SIGNAL(valueChanged(int));
case 2: return SIGNAL(currentIndexChanged(int));
case 3: return SIGNAL(dateTimeChanged(QDateTime));
case 4: return SIGNAL(textChanged(QString));
case 5: return SIGNAL(currentRowChanged(int));
case 6: return SIGNAL(valueChanged(int));
};
Q_STATIC_ASSERT(7 == NFallbackDefaultProperties);
Q_UNREACHABLE();
return 0;
}
class QWizardDefaultProperty class QWizardDefaultProperty
{ {
@ -737,10 +756,10 @@ void QWizardPrivate::init()
updateButtonLayout(); updateButtonLayout();
for (int i = 0; i < NFallbackDefaultProperties; ++i) for (uint i = 0; i < NFallbackDefaultProperties; ++i)
defaultPropertyTable.append(QWizardDefaultProperty(fallbackProperties[i].className, defaultPropertyTable.append(QWizardDefaultProperty(fallbackProperties[i].className,
fallbackProperties[i].property, fallbackProperties[i].property,
fallbackProperties[i].changedSignal)); changed_signal(i)));
} }
void QWizardPrivate::reset() void QWizardPrivate::reset()