Windows 11 Qt 5.15.x 源码编译，支持C++20

configure -debug-and-release -confirm-license -opensource -platform win32-msvc -prefix "G:\\Qt-Build-5.15.17" -qt-sqlite -qt-pcre -qt-zlib -qt-libpng -qt-libjpeg -qt-freetype -qt-harfbuzz -opengl dynamic -skip qtwebengine -nomake tests -no-compile-examples

set CL=/MP #开启多线程编译
nmake # -j8
nmake install

​

​

​

​4.修改源码

直接编译源码无法编译通过，需要改对源码进行修改，参考：

本版本库的一些备注 :: Fsu0413 的原版 Qt 构建 关于mingw部分

--- qtbase\qmake\Makefile.unix.win32	2024-11-20 21:56:33.000000000 +0800
+++ qtbase\qmake\Makefile.unix.win32	2025-07-24 22:47:07.000000000 +0800
@@ -1,8 +1,8 @@
 EXEEXT = .exe
-EXTRA_CXXFLAGS = -DUNICODE -DMINGW_HAS_SECURE_API=1
+EXTRA_CXXFLAGS = -DUNICODE -DMINGW_HAS_SECURE_API=1 -DWINVER=0x0601 -D_WIN32_WINNT=0x0601
 EXTRA_LFLAGS = -static -s -lole32 -luuid -ladvapi32 -lkernel32 -lnetapi32
 QTOBJS = \
     qfilesystemengine_win.o \
     qfilesystemiterator_win.o \
     qfsfileengine_win.o \
     qlocale_win.o \

------------------------------------------------------------------------------------------------
--- qtbase\src\plugins\platforms\windows\windows.pri	2024-11-20 21:56:33.000000000 +0800
+++ qtbase\src\plugins\platforms\windows\windows.pri	2025-07-25 15:18:27.000000000 +0800
@@ -103,12 +103,13 @@
         SOURCES += $$PWD/qwindowsdrag.cpp
     }
 }
 
 qtConfig(tabletevent) {
     INCLUDEPATH += $$QT_SOURCE_TREE/src/3rdparty/wintab
+	 INCLUDEPATH += $$QT_SOURCE_TREE/src/3rdparty/angle/include
     HEADERS += $$PWD/qwindowstabletsupport.h
     SOURCES += $$PWD/qwindowstabletsupport.cpp
 }
 
 qtConfig(sessionmanager) {
     SOURCES += $$PWD/qwindowssessionmanager.cpp
------------------------------------------------------------------------------------------------
--- qtdeclarative\features\hlsl_bytecode_header.prf	2024-11-20 21:56:37.000000000 +0800
+++ qtdeclarative\features\hlsl_bytecode_header.prf	2025-07-25 15:47:14.000000000 +0800
@@ -1,10 +1,16 @@
+# This variable is from a patch from Fsu0413. In order not to conflict with Qt defined one we use custom prefix
+#$$(DXSDK_DIR)/Utilities/bin/x64/fxc.exe
+mingw: FSU0413_QTDECLARATIVE_FEATURES_FXC = C:/Program Files (x86)/Windows Kits/10/bin/10.0.26100.0/x64/fxc.exe
+else: FSU0413_QTDECLARATIVE_FEATURES_FXC = fxc.exe
+
+
 for (SHADER, HLSL_SHADERS) {
     INPUT = $$eval($${SHADER}.input)
     fxc_$${SHADER}.input = $$INPUT
-    fxc_$${SHADER}.commands = fxc.exe /nologo /E $$eval($${SHADER}.entry) /T $$eval($${SHADER}.type) /Fh ${QMAKE_FILE_OUT} ${QMAKE_FILE_NAME}
+    fxc_$${SHADER}.commands = $$FSU0413_QTDECLARATIVE_FEATURES_FXC /nologo /E $$eval($${SHADER}.entry) /T $$eval($${SHADER}.type) /Fh ${QMAKE_FILE_OUT} ${QMAKE_FILE_NAME}
     fxc_$${SHADER}.output = $$eval($${SHADER}.header)
     fxc_$${SHADER}.dependency_type = TYPE_C
     fxc_$${SHADER}.variable_out = HEADERS
     fxc_$${SHADER}.CONFIG += target_predeps
     QMAKE_EXTRA_COMPILERS += fxc_$${SHADER}
 }
------------------------------------------------------------------------------------------------
--- qtdeclarative\src\plugins\scenegraph\d3d12\qsgd3d12engine.cpp	2024-11-20 21:56:37.000000000 +0800
+++ qtdeclarative\src\plugins\scenegraph\d3d12\qsgd3d12engine.cpp	2025-07-27 18:38:30.000000000 +0800
@@ -60,12 +60,16 @@
 #include <windows.ui.xaml.h>
 #include <windows.ui.xaml.media.dxinterop.h>
 #endif
 
 #include <comdef.h>
 
+#ifdef Q_CC_MINGW
+#include <d3d12sdklayers.h>
+#endif
+
 QT_BEGIN_NAMESPACE
 
 // NOTE: Avoid categorized logging. It is slow.
 
 #define DECLARE_DEBUG_VAR(variable) \
     static bool debug_ ## variable() \
@@ -218,13 +222,13 @@
 
     if (qEnvironmentVariableIsSet("QT_D3D_ADAPTER_INDEX")) {
         const int adapterIndex = qEnvironmentVariableIntValue("QT_D3D_ADAPTER_INDEX");
         if (SUCCEEDED(factory->EnumAdapters1(adapterIndex, &adapter))) {
             adapter->GetDesc1(&desc);
             const QString name = QString::fromUtf16((char16_t *) desc.Description);
-            HRESULT hr = D3D12CreateDevice(adapter.Get(), fl, _uuidof(ID3D12Device), nullptr);
+            HRESULT hr = D3D12CreateDevice(adapter.Get(), fl, __uuidof(ID3D12Device), nullptr);
             if (SUCCEEDED(hr)) {
                 qCDebug(QSG_LOG_INFO_GENERAL, "Using requested adapter '%s'", qPrintable(name));
                 *outAdapter = adapter.Detach();
                 return;
             } else {
                 qWarning("Failed to create device for requested adapter '%s': %s",
@@ -235,13 +239,13 @@
 
     for (int adapterIndex = 0; factory->EnumAdapters1(adapterIndex, &adapter) != DXGI_ERROR_NOT_FOUND; ++adapterIndex) {
         adapter->GetDesc1(&desc);
         if (desc.Flags & DXGI_ADAPTER_FLAG_SOFTWARE)
             continue;
 
-        if (SUCCEEDED(D3D12CreateDevice(adapter.Get(), fl, _uuidof(ID3D12Device), nullptr))) {
+        if (SUCCEEDED(D3D12CreateDevice(adapter.Get(), fl, __uuidof(ID3D12Device), nullptr))) {
             const QString name = QString::fromUtf16((char16_t *) desc.Description);
             qCDebug(QSG_LOG_INFO_GENERAL, "Using adapter '%s'", qPrintable(name));
             break;
         }
     }
 
@@ -714,13 +718,14 @@
     deviceManager()->unref();
 
     initialized = false;
 
     // 'window' must be kept, may just be a device loss
 }
-
+const int QSGD3D12EnginePrivate::MAX_SWAP_CHAIN_BUFFER_COUNT;
+const int QSGD3D12EnginePrivate::MAX_FRAME_IN_FLIGHT_COUNT;
 void QSGD3D12EnginePrivate::initialize(WId w, const QSize &size, float dpr, int surfaceFormatSamples, bool alpha)
 {
     if (initialized)
         return;
 
     window = w;


--------------------其他修改，跟编译报错无关----------------------------------------------------------------------------
diff -r qtbase\src\widgets\dialogs\qfiledialog_p.h qtbase\src\widgets\dialogs\qfiledialog_p.h
99c99
< struct QFileDialogArgs
---
> struct Q_WIDGETS_EXPORT QFileDialogArgs

注：“C:/Program Files (x86)/Windows Kits/10/bin/10.0.26100.0/x64/fxc.exe” 为 实际 fxc 程序路径