Qt Core学习日记——第一天Moc文件
深度
本文主要分析Windows平台，Mac、Linux暂不涉及
本文只分析到Win32 API/Windows Com组件/STL库函数层次，再下层代码不做探究
本文QT版本5.15.2
Moc
头文件XTest.h：
#pragma once
#include
class XTest : public QObject
{
Q_OBJECT
Q_CLASSINFO("author", "Sabrina Schweinsteiger")
public:
XTest(QObject* p = nullptr);
~XTest();
public slots:
void slot1(double * p1);
Q_INVOKABLE void slot2(int * p2);
Q_REVISION(1) void slot3(char * p3);
signals:
void sig1(void * p4);
};
cpp文件XTest.cpp:
/****************************************************************************
** Meta object code from reading C++ file 'XTest.h'
**
** Created by: The Qt Meta Object Compiler version 67 (Qt 5.15.2)
**
** WARNING! All changes made in this file will be lost!
*****************************************************************************/
#include
#include "../../../XTest.h"
#include
#include
#if !defined(Q_MOC_OUTPUT_REVISION)
#error "The header file 'XTest.h' doesn't include
#elif Q_MOC_OUTPUT_REVISION != 67
#error "This file was generated using the moc from 5.15.2. It"
#error "cannot be used with the include files from this version of Qt."
#error "(The moc has changed too much.)"
#endif
QT_BEGIN_MOC_NAMESPACE
QT_WARNING_PUSH
QT_WARNING_DISABLE_DEPRECATED
struct qt_meta_stringdata_XTest_t {
QByteArrayData data[15];
char stringdata0[91];
};
#define QT_MOC_LITERAL(idx, ofs, len) \
Q_STATIC_BYTE_ARRAY_DATA_HEADER_INITIALIZER_WITH_OFFSET(len, \
qptrdiff(offsetof(qt_meta_stringdata_XTest_t, stringdata0) + ofs \
- idx * sizeof(QByteArrayData)) \
)
static const qt_meta_stringdata_XTest_t qt_meta_stringdata_XTest = {
{
QT_MOC_LITERAL(0, 0, 5), // "XTest"
QT_MOC_LITERAL(1, 6, 6), // "author"
QT_MOC_LITERAL(2, 13, 22), // "Sabrina Schweinsteiger"
QT_MOC_LITERAL(3, 36, 4), // "sig1"
QT_MOC_LITERAL(4, 41, 0), // ""
QT_MOC_LITERAL(5, 42, 2), // "p4"
QT_MOC_LITERAL(6, 45, 5), // "slot1"
QT_MOC_LITERAL(7, 51, 7), // "double*"
QT_MOC_LITERAL(8, 59, 2), // "p1"
QT_MOC_LITERAL(9, 62, 5), // "slot2"
QT_MOC_LITERAL(10, 68, 4), // "int*"
QT_MOC_LITERAL(11, 73, 2), // "p2"
QT_MOC_LITERAL(12, 76, 5), // "slot3"
QT_MOC_LITERAL(13, 82, 5), // "char*"
QT_MOC_LITERAL(14, 88, 2) // "p3"
},
"XTest\0author\0Sabrina Schweinsteiger\0"
"sig1\0\0p4\0slot1\0double*\0p1\0slot2\0int*\0"
"p2\0slot3\0char*\0p3"
};
#undef QT_MOC_LITERAL
static const uint qt_meta_data_XTest[] = {
// content:
8, // revision
0, // classname
1, 14, // classinfo
4, 16, // methods
0, 0, // properties
0, 0, // enums/sets
0, 0, // constructors
0, // flags
1, // signalCount
// classinfo: key, value
1, 2,
// signals: name, argc, parameters, tag, flags
3, 1, 40, 4, 0x06 /* Public */,
// slots: name, argc, parameters, tag, flags
6, 1, 43, 4, 0x0a /* Public */,
9, 1, 46, 4, 0x0a /* Public */,
12, 1, 49, 4, 0x8a /* Public | MethodRevisioned */,
// signals: revision
0,
// slots: revision
0,
0,
1,
// signals: parameters
QMetaType::Void, QMetaType::VoidStar, 5,
// slots: parameters
QMetaType::Void, 0x80000000 | 7, 8,
QMetaType::Void, 0x80000000 | 10, 11,
QMetaType::Void, 0x80000000 | 13, 14,
0 // eod
};
void XTest::qt_static_metacall(QObject *_o, QMetaObject::Call _c, int _id, void **_a)
{
if (_c == QMetaObject::InvokeMetaMethod) {
auto *_t = static_cast
Q_UNUSED(_t)
switch (_id) {
case 0: _t->sig1((*reinterpret_cast< void*(*)>(_a[1]))); break;
case 1: _t->slot1((*reinterpret_cast< double*(*)>(_a[1]))); break;
case 2: _t->slot2((*reinterpret_cast< int*(*)>(_a[1]))); break;
case 3: _t->slot3((*reinterpret_cast< char*(*)>(_a[1]))); break;
default: ;
}
} else if (_c == QMetaObject::IndexOfMethod) {
int *result = reinterpret_cast
{
using _t = void (XTest::*)(void * );
if (*reinterpret_cast<_t *>(_a[1]) == static_cast<_t>(&XTest::sig1)) {
*result = 0;
return;
}
}
}
}
QT_INIT_METAOBJECT const QMetaObject XTest::staticMetaObject = { {
QMetaObject::SuperData::link
qt_meta_stringdata_XTest.data,
qt_meta_data_XTest,
qt_static_metacall,
nullptr,
nullptr
} };
const QMetaObject *XTest::metaObject() const
{
return QObject::d_ptr->metaObject ? QObject::d_ptr->dynamicMetaObject() : &staticMetaObject;
}
void *XTest::qt_metacast(const char *_clname)
{
if (!_clname) return nullptr;
if (!strcmp(_clname, qt_meta_stringdata_XTest.stringdata0))
return static_cast
return QObject::qt_metacast(_clname);
}
int XTest::qt_metacall(QMetaObject::Call _c, int _id, void **_a)
{
_id = QObject::qt_metacall(_c, _id, _a);
if (_id < 0)
return _id;
if (_c == QMetaObject::InvokeMetaMethod) {
if (_id < 4)
qt_static_metacall(this, _c, _id, _a);
_id -= 4;
} else if (_c == QMetaObject::RegisterMethodArgumentMetaType) {
if (_id < 4)
*reinterpret_cast
_id -= 4;
}
return _id;
}
// SIGNAL 0
void XTest::sig1(void * _t1)
{
void *_a[] = { nullptr, const_cast
QMetaObject::activate(this, &staticMetaObject, 0, _a);
}
QT_WARNING_POP
QT_END_MOC_NAMESPACE
QT_BEGIN_MOC_NAMESPACE
如果没有定义QT_NAMESPACE或者定义了Q_MOC_RUN则为空
否则为using namespace ::QT_NAMESPACE
默认QT_BEGIN_MOC_NAMESPACE为空
QT_WARNING_PUSH
默认定义__pragma(warning(push))，存储每个警告的当前警告状态
QT_WARNING_DISABLE_DEPRECATED
__pragma(warning(disable: 4996))关闭编译警告4996
qt_meta_stringdata_XTest_t
定义数据结构用于存储元数据信息，包括类名称、函数名称
data、stringdata0并不是恒定大小，依照头文件定义函数、参数数量决定
QT_MOC_LITERAL
用于指定函数名称的位置
#define QT_MOC_LITERAL(idx, ofs, len) \
{ { {-1} }, len, 0, 0, qptrdiff(((::size_t)&reinterpret_cast
qt_meta_stringdata_XTest
存储当前类的元数据信息
static const qt_meta_stringdata_XTest_t qt_meta_stringdata_XTest = {
{
QT_MOC_LITERAL(0, 0, 5), // "XTest"
QT_MOC_LITERAL(1, 6, 6), // "author"
QT_MOC_LITERAL(2, 13, 22), // "Sabrina Schweinsteiger"
QT_MOC_LITERAL(3, 36, 4), // "sig1"
QT_MOC_LITERAL(4, 41, 0), // ""
QT_MOC_LITERAL(5, 42, 2), // "p4"
QT_MOC_LITERAL(6, 45, 5), // "slot1"
QT_MOC_LITERAL(7, 51, 7), // "double*"
QT_MOC_LITERAL(8, 59, 2), // "p1"
QT_MOC_LITERAL(9, 62, 5), // "slot2"
QT_MOC_LITERAL(10, 68, 4), // "int*"
QT_MOC_LITERAL(11, 73, 2), // "p2"
QT_MOC_LITERAL(12, 76, 5), // "slot3"
QT_MOC_LITERAL(13, 82, 5), // "char*"
QT_MOC_LITERAL(14, 88, 2) // "p3"
},
"XTest\0author\0Sabrina Schweinsteiger\0"
"sig1\0\0p4\0slot1\0double*\0p1\0slot2\0int*\0"
"p2\0slot3\0char*\0p3"
};
将宏翻译后得
static const qt_meta_stringdata_XTest_t qt_meta_stringdata_XTest = {
{
QT_MOC_LITERAL(0, 0, 5), // "XTest"
{-1,5,0,0,0x90},//是对QByteArrayData的定义
QT_MOC_LITERAL(1, 6, 6), // "author"
QT_MOC_LITERAL(2, 13, 22), // "Sabrina Schweinsteiger"
QT_MOC_LITERAL(3, 36, 4), // "sig1"
QT_MOC_LITERAL(4, 41, 0), // ""
QT_MOC_LITERAL(5, 42, 2), // "p4"
QT_MOC_LITERAL(6, 45, 5), // "slot1"
QT_MOC_LITERAL(7, 51, 7), // "double*"
QT_MOC_LITERAL(8, 59, 2), // "p1"
QT_MOC_LITERAL(9, 62, 5), // "slot2"
QT_MOC_LITERAL(10, 68, 4), // "int*"
QT_MOC_LITERAL(11, 73, 2), // "p2"
QT_MOC_LITERAL(12, 76, 5), // "slot3"
QT_MOC_LITERAL(13, 82, 5), // "char*"
QT_MOC_LITERAL(14, 88, 2) // "p3"
},
"XTest\0author\0Sabrina Schweinsteiger\0"
//类名称后接classinfo定义‘\0’隔开
"sig1\0\0p4\0slot1\0double*\0p1\0slot2\0int*\0"
"p2\0slot3\0char*\0p3"
};
QT_MOC_LITERAL(0, 0, 5),定义的是"XTest\0sig1\0\0slot1\0slot2\0slot3"中"XTest"的位置，类型为QByteArray.替换宏后为{-1,5,0,0,0x90}，-1是QByteArray的引用计数，5为QByteArrayData的大小，0为分配地址,0为预留容量，0x90为"XTest\0author\0Sabrina Schweinsteiger\0"中"XTest"的首位置
假若h文件中函数改为
void slot1(double * p1);
Q_INVOKABLE void slot2(int * p2);
Q_REVISION(1) void slot3(char * p3);
qt_meta_stringdata_XTest变化如下：
static const qt_meta_stringdata_XTest_t qt_meta_stringdata_XTest = {
{
QT_MOC_LITERAL(0, 0, 5), // "XTest"
QT_MOC_LITERAL(1, 6, 4), // "sig1"
QT_MOC_LITERAL(2, 11, 0), // ""
QT_MOC_LITERAL(3, 12, 5), // "slot1"
QT_MOC_LITERAL(4, 18, 7), // "double*"
QT_MOC_LITERAL(5, 26, 2), // "p1"
QT_MOC_LITERAL(6, 29, 5), // "slot2"
QT_MOC_LITERAL(7, 35, 4), // "int*"
QT_MOC_LITERAL(8, 40, 2), // "p2"
QT_MOC_LITERAL(9, 43, 5), // "slot3"
QT_MOC_LITERAL(10, 49, 5), // "char*"
QT_MOC_LITERAL(11, 55, 2) // "p3"
},
"XTest\0sig1\0\0slot1\0double*\0p1\0slot2\0"
"int*\0p2\0slot3\0char*\0p3"
};
每个函数QT_MOC_LITERAL(3, 12, 5), // "slot1"定义下面紧接QT_MOC_LITERAL(4, 18, 7), // "double*"参数类型，类型后面接参数名称QT_MOC_LITERAL(5, 26, 2), // "p1"
qt_meta_data_XTest
static const uint qt_meta_data_XTest[] = {
// content:
8, // revision
0, // classname
0, 0, // classinfo
4, 14, // methods
0, 0, // properties
0, 0, // enums/sets
0, 0, // constructors
0, // flags
1, // signalCount
// signals: name, argc, parameters, tag, flags
1, 0, 38, 2, 0x06 /* Public */,
// slots: name, argc, parameters, tag, flags
3, 1, 39, 2, 0x0a /* Public */,
6, 1, 42, 2, 0x0a /* Public */,
9, 1, 45, 2, 0x8a /* Public | MethodRevisioned */,
// signals: revision
0,
// slots: revision
0,
0,
1,
// signals: parameters
QMetaType::Void,
// slots: parameters
QMetaType::Void, 0x80000000 | 4, 5,
QMetaType::Void, 0x80000000 | 7, 8,
QMetaType::Void, 0x80000000 | 10, 11,
0 // eod
};
3, 1, 39, 2, 0x0a /* Public */,3代表QT_MOC_LITERAL(3, 12, 5), // "slot1"函数，1参数数量，39代表参数“p1”位置，0x0a代表函数属性
XTest::qt_static_metacall
主要对外函数调用，消息循环触发过来时通过此函数调用到槽函数
QMetaObject *XTest::metaObject
获取QObject元数据QMetaObject
写到最后
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