cmake NCNN_WINXP option, do not define _WIN32_WINNT macro (Tencent#6430)

Author: nihui

.github/workflows/windows-xp-clang.yml

@@ -56,7 +56,7 @@ jobs:
     - name: build
       run: |
         mkdir build; cd build
-        cmake ${{ env.NCNN_CMAKE_OPTIONS }} -DCMAKE_TOOLCHAIN_FILE="../toolchains/windows-xp-clang.toolchain.cmake" -DNCNN_SIMPLEOCV=ON -DNCNN_SIMPLEOMP=ON -DNCNN_AVX2=OFF -DNCNN_AVX=OFF .. -G "MinGW Makefiles"
+        cmake ${{ env.NCNN_CMAKE_OPTIONS }} -DCMAKE_TOOLCHAIN_FILE="../toolchains/windows-xp-clang.toolchain.cmake" -DNCNN_WINXP=ON -DNCNN_SIMPLEOCV=ON -DNCNN_SIMPLEOMP=ON -DNCNN_AVX2=OFF -DNCNN_AVX=OFF .. -G "MinGW Makefiles"
         cmake --build . --config Release -j 4
     - name: test
-      run: cd build; ctest -C Release --output-on-failure -j 4
+      run: cd build; ctest -C Release --output-on-failure -j 4

.github/workflows/windows-xp-mingw.yml

@@ -51,7 +51,7 @@ jobs:
     - name: build
       run: |
         mkdir build; cd build
-        cmake ${{ env.NCNN_CMAKE_OPTIONS }} -DCMAKE_TOOLCHAIN_FILE="../toolchains/windows-xp-mingw.toolchain.cmake" -DNCNN_SIMPLEOCV=ON -DNCNN_AVX2=OFF -DNCNN_AVX=OFF -DNCNN_VULKAN=OFF .. -G "MinGW Makefiles"
+        cmake ${{ env.NCNN_CMAKE_OPTIONS }} -DCMAKE_TOOLCHAIN_FILE="../toolchains/windows-xp-mingw.toolchain.cmake" -DNCNN_WINXP=ON -DNCNN_SIMPLEOCV=ON -DNCNN_AVX2=OFF -DNCNN_AVX=OFF -DNCNN_VULKAN=OFF .. -G "MinGW Makefiles"
         cmake --build . --config Release -j 4
     - name: test
-      run: cd build; ctest -C Release --output-on-failure -j 4
+      run: cd build; ctest -C Release --output-on-failure -j 4

.github/workflows/windows-xp-msvc.yml

@@ -50,7 +50,7 @@ jobs:
     - name: build
       run: |
         mkdir build; cd build
-        cmake ${{ env.NCNN_CMAKE_OPTIONS }} -A WIN32 -G "Visual Studio 17 2022" -T v141_xp -DNCNN_SIMPLEOCV=ON -DNCNN_OPENMP=OFF -DNCNN_BUILD_WITH_STATIC_CRT=ON -DNCNN_AVX2=OFF -DNCNN_AVX=OFF -DCMAKE_TOOLCHAIN_FILE="../toolchains/windows-xp-msvc.toolchain.cmake" ..
+        cmake ${{ env.NCNN_CMAKE_OPTIONS }} -A WIN32 -G "Visual Studio 17 2022" -T v141_xp -DNCNN_WINXP=ON -DNCNN_SIMPLEOCV=ON -DNCNN_OPENMP=OFF -DNCNN_BUILD_WITH_STATIC_CRT=ON -DNCNN_AVX2=OFF -DNCNN_AVX=OFF -DCMAKE_TOOLCHAIN_FILE="../toolchains/windows-xp-msvc.toolchain.cmake" ..
         cmake --build . --config Release -j 4
     - name: test
-      run: cd build; ctest -C Release --output-on-failure -j 4
+      run: cd build; ctest -C Release --output-on-failure -j 4

CMakeLists.txt

@@ -71,6 +71,7 @@ option(NCNN_THREADS "build with threads" ON)
 option(NCNN_BENCHMARK "print benchmark information for every layer" OFF)
 option(NCNN_C_API "build with C api" ON)
 option(NCNN_PLATFORM_API "build with platform api candy" ON)
+option(NCNN_WINXP "build with windows xp compatibility" OFF)
 option(NCNN_PIXEL "convert and resize from/to image pixel" ON)
 option(NCNN_PIXEL_ROTATE "rotate image pixel orientation" ON)
 option(NCNN_PIXEL_AFFINE "warp affine image pixel" ON)

docs/how-to-build/how-to-build.md

@@ -278,7 +278,7 @@ Download mingw toolchain targeting 32 bit from [sourceforge](https://jaist.dl.so
 ```shell
 mkdir build
 cd build
-cmake -DCMAKE_TOOLCHAIN_FILE="../toolchains/windows-xp-mingw.toolchain.cmake" -DNCNN_SIMPLEOCV=ON -DNCNN_AVX2=OFF -DNCNN_AVX=OFF -DNCNN_VULKAN=OFF .. -G "MinGW Makefiles"
+cmake -DCMAKE_TOOLCHAIN_FILE="../toolchains/windows-xp-mingw.toolchain.cmake" -DNCNN_WINXP=ON -DNCNN_SIMPLEOCV=ON -DNCNN_AVX2=OFF -DNCNN_AVX=OFF -DNCNN_VULKAN=OFF .. -G "MinGW Makefiles"
 cmake --build . --config Release -j 4
 cmake --build . --config Release --target install
 ```
@@ -292,7 +292,7 @@ Install Clang 6.0 or later.
 ```shell
 mkdir build
 cd build
-cmake -DCMAKE_TOOLCHAIN_FILE="../toolchains/windows-xp-clang.toolchain.cmake" -DNCNN_SIMPLEOCV=ON -DNCNN_SIMPLEOMP=ON -DNCNN_AVX2=OFF -DNCNN_AVX=OFF .. -G "MinGW Makefiles"
+cmake -DCMAKE_TOOLCHAIN_FILE="../toolchains/windows-xp-clang.toolchain.cmake" -DNCNN_WINXP=ON -DNCNN_SIMPLEOCV=ON -DNCNN_SIMPLEOMP=ON -DNCNN_AVX2=OFF -DNCNN_AVX=OFF .. -G "MinGW Makefiles"
 cmake --build . --config Release -j 4
 cmake --build . --config Release --target install
 ```
@@ -309,7 +309,7 @@ Install v141_xp toolset for Windows XP:
 ```shell
 mkdir build
 cd build
-cmake -A WIN32 -G "Visual Studio 17 2022" -T v141_xp -DNCNN_SIMPLEOCV=ON -DNCNN_OPENMP=OFF -DNCNN_AVX2=OFF -DNCNN_AVX=OFF -DNCNN_BUILD_WITH_STATIC_CRT=ON -DCMAKE_TOOLCHAIN_FILE="../toolchains/windows-xp-msvc.toolchain.cmake" ..
+cmake -A WIN32 -G "Visual Studio 17 2022" -T v141_xp -DNCNN_WINXP=ON -DNCNN_SIMPLEOCV=ON -DNCNN_OPENMP=OFF -DNCNN_AVX2=OFF -DNCNN_AVX=OFF -DNCNN_BUILD_WITH_STATIC_CRT=ON -DCMAKE_TOOLCHAIN_FILE="../toolchains/windows-xp-msvc.toolchain.cmake" ..
 cmake --build . --config Release -j 2
 cmake --build . --config Release --target install
 ```

src/platform.h.in

@@ -14,6 +14,7 @@
 #cmakedefine01 NCNN_BENCHMARK
 #cmakedefine01 NCNN_C_API
 #cmakedefine01 NCNN_PLATFORM_API
+#cmakedefine01 NCNN_WINXP
 #cmakedefine01 NCNN_PIXEL
 #cmakedefine01 NCNN_PIXEL_ROTATE
 #cmakedefine01 NCNN_PIXEL_AFFINE
@@ -67,9 +68,6 @@
 #if NCNN_THREADS
 #if defined _WIN32
 #define WIN32_LEAN_AND_MEAN
-#ifndef _WIN32_WINNT
-#define _WIN32_WINNT 0x0501
-#endif
 #include <windows.h>
 #include <process.h>
 #else
@@ -87,33 +85,7 @@ namespace ncnn {
 
 #if NCNN_THREADS
 #if defined _WIN32
-#if _WIN32_WINNT > _WIN32_WINNT_WINXP // Windows Vista and later
-class NCNN_EXPORT Mutex
-{
-public:
-    Mutex() { InitializeSRWLock(&srwlock); }
-    ~Mutex() {}
-    void lock() { AcquireSRWLockExclusive(&srwlock); }
-    void unlock() { ReleaseSRWLockExclusive(&srwlock); }
-private:
-    friend class ConditionVariable;
-    SRWLOCK srwlock;
-};
-
-class NCNN_EXPORT ConditionVariable
-{
-public:
-    ConditionVariable() { InitializeConditionVariable(&condvar); }
-    ~ConditionVariable() {}
-    void wait(Mutex& mutex) { SleepConditionVariableSRW(&condvar, &mutex.srwlock, INFINITE, 0); }
-    void broadcast() { WakeAllConditionVariable(&condvar); }
-    void signal() { WakeConditionVariable(&condvar); }
-private:
-    CONDITION_VARIABLE condvar;
-};
-
-#else // Windows XP compatibility
-
+#if NCNN_WINXP
 class NCNN_EXPORT Mutex
 {
 public:
@@ -129,15 +101,15 @@ private:
 class NCNN_EXPORT ConditionVariable
 {
 public:
-    ConditionVariable() 
-    { 
+    ConditionVariable()
+    {
         signal_event = CreateEvent(0, FALSE, FALSE, 0); // Auto-reset event for signal()
         broadcast_event = CreateEvent(0, TRUE, FALSE, 0); // Manual-reset event for broadcast()
     }
-    ~ConditionVariable() 
-    { 
-        CloseHandle(signal_event); 
-        CloseHandle(broadcast_event); 
+    ~ConditionVariable()
+    {
+        CloseHandle(signal_event);
+        CloseHandle(broadcast_event);
     }
     void wait(Mutex& mutex)
     {
@@ -146,21 +118,44 @@ public:
         WaitForMultipleObjects(2, events, FALSE, INFINITE); // Wait for either signal or broadcast
         mutex.lock();
     }
-    void broadcast() 
-    { 
+    void broadcast()
+    {
         SetEvent(broadcast_event); // Wake all threads
         ResetEvent(broadcast_event); // Reset after waking all threads
     }
-    void signal() 
-    { 
+    void signal()
+    {
         SetEvent(signal_event); // Wake one thread
     }
 private:
     HANDLE signal_event;
     HANDLE broadcast_event;
 };
+#else // NCNN_WINXP
+class NCNN_EXPORT Mutex
+{
+public:
+    Mutex() { InitializeSRWLock(&srwlock); }
+    ~Mutex() {}
+    void lock() { AcquireSRWLockExclusive(&srwlock); }
+    void unlock() { ReleaseSRWLockExclusive(&srwlock); }
+private:
+    friend class ConditionVariable;
+    SRWLOCK srwlock;
+};
 
-#endif // _WIN32_WINNT > _WIN32_WINNT_WINXP
+class NCNN_EXPORT ConditionVariable
+{
+public:
+    ConditionVariable() { InitializeConditionVariable(&condvar); }
+    ~ConditionVariable() {}
+    void wait(Mutex& mutex) { SleepConditionVariableSRW(&condvar, &mutex.srwlock, INFINITE, 0); }
+    void broadcast() { WakeAllConditionVariable(&condvar); }
+    void signal() { WakeConditionVariable(&condvar); }
+private:
+    CONDITION_VARIABLE condvar;
+};
+#endif // NCNN_WINXP
 
 static unsigned __stdcall start_wrapper(void* args);
 class NCNN_EXPORT Thread