From 01499d51505b5ef9c99fcedb599db4fbd91425be Mon Sep 17 00:00:00 2001
From: Pratham Kumar <pratham.kumar@multicorewareinc.com>
Date: Wed, 28 Oct 2026 13:30:02 +0530
Subject: [PATCH] cmake: enable clang-cl build on Windows ARM64 with KleidiCV

---
 CMakeLists.txt                      | 2 +-
 cmake/OpenCVCompilerOptions.cmake   | 2 +-
 cmake/OpenCVDetectCXXCompiler.cmake | 4 ++++
 hal/carotene/CMakeLists.txt         | 2 +-
 hal/kleidicv/CMakeLists.txt         | 7 +++++++
 modules/core/CMakeLists.txt         | 4 ++++
 modules/ts/CMakeLists.txt           | 4 ++++
 7 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index eea07f85ac..4edf5485cb 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -179,7 +179,7 @@ OCV_OPTION(WITH_CAP_IOS "Enable iOS video capture" ON
 OCV_OPTION(WITH_CAROTENE "Use NVidia carotene acceleration library for ARM platform" (NOT CV_DISABLE_OPTIMIZATION)
   VISIBLE_IF (ARM OR AARCH64) AND NOT IOS AND NOT XROS)
 OCV_OPTION(WITH_KLEIDICV "Use KleidiCV library for ARM platforms" (NOT CV_DISABLE_OPTIMIZATION)
-  VISIBLE_IF (AARCH64 AND (ANDROID OR UNIX)))
+  VISIBLE_IF (AARCH64 AND (ANDROID OR UNIX OR CV_CLANG_CL)))
 OCV_OPTION(WITH_NDSRVP "Use Andes RVP extension" (NOT CV_DISABLE_OPTIMIZATION)
   VISIBLE_IF RISCV)
 OCV_OPTION(WITH_HAL_RVV "Use HAL RVV optimizations" (NOT CV_DISABLE_OPTIMIZATION)
diff --git a/cmake/OpenCVCompilerOptions.cmake b/cmake/OpenCVCompilerOptions.cmake
index bcfdb6639c..25a7f93740 100644
--- a/cmake/OpenCVCompilerOptions.cmake
+++ b/cmake/OpenCVCompilerOptions.cmake
@@ -320,7 +320,7 @@ if(MSVC)
     set(OPENCV_EXTRA_CXX_FLAGS "${OPENCV_EXTRA_CXX_FLAGS} /FS")
   endif()
 
-  if(AARCH64 AND NOT MSVC_VERSION LESS 1930)
+  if(AARCH64 AND NOT MSVC_VERSION LESS 1930 AND NOT CV_CLANG_CL)
     set(OPENCV_EXTRA_FLAGS "${OPENCV_EXTRA_FLAGS} /D _ARM64_DISTINCT_NEON_TYPES")
   endif()
 endif()
diff --git a/cmake/OpenCVDetectCXXCompiler.cmake b/cmake/OpenCVDetectCXXCompiler.cmake
index e07bc9eb1e..2522ac04f7 100644
--- a/cmake/OpenCVDetectCXXCompiler.cmake
+++ b/cmake/OpenCVDetectCXXCompiler.cmake
@@ -1,6 +1,7 @@
 # Compilers:
 # - CV_GCC - GNU compiler (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
 # - CV_CLANG - Clang-compatible compiler (CMAKE_CXX_COMPILER_ID MATCHES "Clang" - Clang or AppleClang, see CMP0025)
+# - CV_CLANG_CL - clang-cl, Clang with MSVC-compatible command line (CV_CLANG AND MSVC)
 # - CV_ICC - Intel compiler
 # - MSVC - Microsoft Visual Compiler (CMake variable)
 # - MINGW / CYGWIN / CMAKE_COMPILER_IS_MINGW / CMAKE_COMPILER_IS_CYGWIN (CMake original variables)
@@ -29,6 +30,9 @@ endif()
 if(NOT DEFINED CV_CLANG AND CMAKE_CXX_COMPILER_ID MATCHES "Clang")  # Clang or AppleClang (see CMP0025)
   set(CV_CLANG 1)
 endif()
+if(NOT DEFINED CV_CLANG_CL AND CV_CLANG AND MSVC)
+  set(CV_CLANG_CL 1)
+endif()
 
 
 # ----------------------------------------------------------------------------
diff --git a/hal/carotene/CMakeLists.txt b/hal/carotene/CMakeLists.txt
index e229cbc022..bb711a0c0a 100644
--- a/hal/carotene/CMakeLists.txt
+++ b/hal/carotene/CMakeLists.txt
@@ -44,7 +44,7 @@ if(WITH_NEON)
     target_compile_definitions(carotene_objs PRIVATE "-DWITH_NEON")
 endif()
 
- if(MINGW)
+ if(MINGW OR CV_CLANG_CL)
     target_compile_definitions(carotene_objs PRIVATE "-D_USE_MATH_DEFINES=1")
  endif()
 
diff --git a/hal/kleidicv/CMakeLists.txt b/hal/kleidicv/CMakeLists.txt
index 5d78c83d2c..3571c9aa3a 100644
--- a/hal/kleidicv/CMakeLists.txt
+++ b/hal/kleidicv/CMakeLists.txt
@@ -9,4 +9,11 @@ if(HAVE_KLEIDICV)
       $<TARGET_PROPERTY:kleidicv,COMPILE_OPTIONS>
       "-Wno-old-style-cast" "-Wno-unused-function"
   )
+  if(CV_CLANG_CL)
+    foreach(_kleidicv_tgt kleidicv kleidicv_neon kleidicv_thread kleidicv_sve2 kleidicv_sme kleidicv_sme2 kleidicv_hal)
+      if(TARGET ${_kleidicv_tgt})
+        target_compile_options(${_kleidicv_tgt} PRIVATE "-Wno-everything")
+      endif()
+    endforeach()
+  endif()
 endif()
diff --git a/modules/core/CMakeLists.txt b/modules/core/CMakeLists.txt
index 33ba422625..52f5e17f0b 100644
--- a/modules/core/CMakeLists.txt
+++ b/modules/core/CMakeLists.txt
@@ -176,6 +176,10 @@ if(HAVE_CUDA)
   ocv_warnings_disable(CMAKE_CXX_FLAGS -Wundef -Wenum-compare -Wunused-function -Wshadow)
 endif()
 
+if(CV_CLANG_CL AND AARCH64)
+  set_source_files_properties("${CMAKE_CURRENT_SOURCE_DIR}/src/persistence.cpp" PROPERTIES COMPILE_OPTIONS "/O1")
+endif()
+
 ocv_create_module(${extra_libs})
 
 ocv_target_link_libraries(${the_module} PRIVATE
diff --git a/modules/ts/CMakeLists.txt b/modules/ts/CMakeLists.txt
index 5f984bd908..ab942d9676 100644
--- a/modules/ts/CMakeLists.txt
+++ b/modules/ts/CMakeLists.txt
@@ -22,6 +22,10 @@ ocv_glob_module_sources()
 ocv_module_include_directories()
 ocv_create_module()
 
+if(CV_CLANG_CL AND AARCH64)
+  set_source_files_properties("${CMAKE_CURRENT_SOURCE_DIR}/src/ts_gtest.cpp" PROPERTIES COMPILE_OPTIONS "/O1")
+endif()
+
 # generate config file
 set(OPENCV_TESTS_CONFIG_FILE "${CMAKE_BINARY_DIR}/opencv_tests_config.hpp")
 set(OPENCV_TESTS_CONFIG_STR "")