Add clang-cl (LLVM) build support on Windows (#14375)

# Description This PR enables building OrcaSlicer on Windows with the **clang-cl (LLVM)** toolchain and the **Ninja** generator, in addition to the existing MSVC path. Clang is already supported on Linux with this codebase, so this extends that support to Windows. The changes fall into three categories. All are either no-ops on the existing MSVC/Visual Studio path or Windows/clang-cl-specific, so the standard build is not affected. ### 1. C++ conformance fixes clang-cl is stricter than MSVC and rejects several constructs that cl.exe silently accepted. Each of these is non-conforming code that MSVC tolerated: * **Explicit template instantiation in `BoundingBox.cpp`** — clang-cl does not instantiate `BoundingBoxBase<Point, Points>::construct` through the same transitive path MSVC uses; added the explicit instantiation. * **Eigen cast materialization in `AABBTreeLines.hpp`** — `.cast<T>()` returns a lazy `CwiseUnaryOp`, not a concrete `Matrix`; materialized it before passing to `distance_to_squared`, which expects a concrete type. * **`LabelItemType` underlying type in `PresetComboBoxes.hpp`** — gave the enum the same `std::size_t` underlying type as `Marker` to resolve a narrowing conversion in a switch. * **`T2A_` cast in `BaseException.cpp`** — explicit `static_cast<const char*>` on the ATL conversion helper result. * **Wide string literals in `GUI_App.cpp`** — used `L""` literals where concatenated with a `std::wstring` (`url_prefix`). ### 2. Build system / dependencies * **Exclude clang-cl from MSVC-only CMake guards** — `if(MSVC)` is true for clang-cl, so blocks applying cl.exe-only flags now exclude Clang. * **Disable TBB LTCG** — oneTBB enables MSVC IPO/LTCG by default, emitting proprietary `/GL` bitcode objects that `lld-link` cannot consume. Disabling IPO produces native COFF, linkable by both `link.exe` and `lld-link`. TBB is threading infrastructure, so the runtime impact of disabling LTCG is negligible. * **wxWidgets target path** — clang-cl uses the MSVC frontend variant on Windows but reports compiler id `Clang`, so wxWidgets looked under `clang_x64_lib` instead of the `vc_x64_lib` layout the deps are built with. ### 3. Ninja generator support * **Runtime DLL copy** — the DLL copy step was nested under `CMAKE_CONFIGURATION_TYPES` (multi-config only), so single-config Ninja skipped copying OCCT/GMP/MPFR/WebView2/freetype DLLs next to the executable. Now runs for both generator styles, guarded by `if(WIN32)`. * **`build_release_vs.bat` Ninja target** — `ALL_BUILD` is a Visual Studio target; Ninja uses `all`. The script failed with `ninja: error: unknown target 'ALL_BUILD'` when invoked with `-x`. ## Tests Built from a clean checkout on Windows with: * clang-cl 22 (LLVM toolchain bundled with Visual Studio 18) * Ninja Multi-Config generator * lld-link as the linker The full build (deps + slicer) compiles, `OrcaSlicer.dll` links with `lld-link`, and `orca-slicer.exe` runs. Verified end-to-end by loading a model, slicing it, and generating valid G-code (screenshot below). The existing MSVC / Visual Studio build path is unaffected — all changes are guarded by compiler/generator/platform checks or are conformance fixes that compile identically under MSVC. # Screenshots <img width="1919" height="1079" alt="image" src="https://github.com/user-attachments/assets/02082437-db36-4696-a91a-d9acf57d4a52" />
2026-08-24 18:37:39 +00:00 · 2026-08-19 13:00:46 +08:00
parent 4fd7fdb3fa 050ebbb1f4
commit 02f148123d
14 changed files with 173 additions and 19 deletions
--- a/build_release_vs.bat
+++ b/build_release_vs.bat
@@ -152,7 +152,7 @@ echo on
 set CMAKE_POLICY_VERSION_MINIMUM=3.5
 if "%USE_NINJA%"=="1" (
    cmake .. -G %CMAKE_GENERATOR% -DORCA_TOOLS=ON %SIG_FLAG% -DBUILD_TESTS=%BUILD_TESTS% -DCMAKE_BUILD_TYPE=%build_type%
-    cmake --build . --config %build_type% --target ALL_BUILD
+    cmake --build . --config %build_type% --target all
 ) else (
    cmake .. -G %CMAKE_GENERATOR% -A %arch% -DORCA_TOOLS=ON %SIG_FLAG% -DBUILD_TESTS=%BUILD_TESTS% -DCMAKE_BUILD_TYPE=%build_type%
    cmake --build . --config %build_type% --target ALL_BUILD -- -m
--- a/deps/TBB/MSVC.cmake
+++ b/deps/TBB/MSVC.cmake
@@ -0,0 +1,98 @@
+# Copyright (c) 2020-2021 Intel Corporation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set(TBB_LINK_DEF_FILE_FLAG ${CMAKE_LINK_DEF_FILE_FLAG})
+set(TBB_DEF_FILE_PREFIX win${TBB_ARCH})
+
+# Workaround for CMake issue https://gitlab.kitware.com/cmake/cmake/issues/18317.
+# TODO: consider use of CMP0092 CMake policy.
+string(REGEX REPLACE "/W[0-4]" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
+
+set(TBB_WARNING_LEVEL $<$<BOOL:${TBB_STRICT}>:/W4> $<$<BOOL:${TBB_STRICT}>:/WX>)
+
+# Warning suppression C4324: structure was padded due to alignment specifier
+set(TBB_WARNING_SUPPRESS /wd4324)
+set(TBB_TEST_COMPILE_FLAGS /bigobj)
+
+if (MSVC_VERSION LESS_EQUAL 1900)
+    # Warning suppression C4503 for VS2015 and earlier:
+    # decorated name length exceeded, name was truncated.
+    # More info can be found at
+    # https://docs.microsoft.com/en-us/cpp/error-messages/compiler-warnings/compiler-warning-level-1-c4503
+    set(TBB_TEST_COMPILE_FLAGS ${TBB_TEST_COMPILE_FLAGS} /wd4503)
+endif()
+
+set(TBB_LIB_COMPILE_FLAGS -D_CRT_SECURE_NO_WARNINGS /GS)
+set(TBB_COMMON_COMPILE_FLAGS /volatile:iso /FS /EHsc)
+
+# Ignore /WX set through add_compile_options() or added to CMAKE_CXX_FLAGS if TBB_STRICT is disabled.
+if (NOT TBB_STRICT AND COMMAND tbb_remove_compile_flag)
+    tbb_remove_compile_flag(/WX)
+endif()
+
+if (WINDOWS_STORE OR TBB_WINDOWS_DRIVER)
+    set(TBB_COMMON_COMPILE_FLAGS ${TBB_COMMON_COMPILE_FLAGS} /D_WIN32_WINNT=0x0A00)
+    set(TBB_COMMON_LINK_FLAGS -NODEFAULTLIB:kernel32.lib -INCREMENTAL:NO)
+    set(TBB_COMMON_LINK_LIBS OneCore.lib)
+endif()
+
+if (WINDOWS_STORE)
+    if (NOT CMAKE_SYSTEM_VERSION EQUAL 10.0)
+        message(FATAL_ERROR "CMAKE_SYSTEM_VERSION must be equal to 10.0")
+    endif()
+    set(TBB_COMMON_COMPILE_FLAGS ${TBB_COMMON_COMPILE_FLAGS} /ZW /ZW:nostdlib)
+    # CMake define this extra lib, remove it for this build type
+    string(REGEX REPLACE "WindowsApp.lib" "" CMAKE_CXX_STANDARD_LIBRARIES "${CMAKE_CXX_STANDARD_LIBRARIES}")
+
+    if (TBB_NO_APPCONTAINER)
+        set(TBB_LIB_LINK_FLAGS ${TBB_LIB_LINK_FLAGS} -APPCONTAINER:NO)
+    endif()
+endif()
+
+if (TBB_WINDOWS_DRIVER)
+    # Since this is universal driver disable this variable
+    set(CMAKE_SYSTEM_PROCESSOR "")
+    # CMake define list additional libs, remove it for this build type
+    set(CMAKE_CXX_STANDARD_LIBRARIES "")
+    set(TBB_COMMON_COMPILE_FLAGS ${TBB_COMMON_COMPILE_FLAGS} /D _UNICODE /DUNICODE /DWINAPI_FAMILY=WINAPI_FAMILY_APP /D__WRL_NO_DEFAULT_LIB__)
+endif()
+
+if (NOT DEFINED TBB_ENABLE_IPO)
+    if (DEFINED CMAKE_INTERPROCEDURAL_OPTIMIZATION)
+        set(TBB_ENABLE_IPO ${CMAKE_INTERPROCEDURAL_OPTIMIZATION})
+    else()
+        set(TBB_ENABLE_IPO ON)
+    endif()
+endif()
+
+if (TBB_ENABLE_IPO)
+    if (CMAKE_CXX_COMPILER_ID MATCHES "(Clang|IntelLLVM)")
+        if (CMAKE_SYSTEM_PROCESSOR MATCHES "(x86|AMD64)")
+            set(TBB_COMMON_COMPILE_FLAGS ${TBB_COMMON_COMPILE_FLAGS} -mrtm -mwaitpkg)
+        endif()
+        set(TBB_OPENMP_NO_LINK_FLAG TRUE)
+        set(TBB_IPO_COMPILE_FLAGS $<$<NOT:$<CONFIG:Debug>>:-flto>)
+    else()
+        set(TBB_IPO_COMPILE_FLAGS $<$<NOT:$<CONFIG:Debug>>:/GL>)
+        set(TBB_IPO_LINK_FLAGS $<$<NOT:$<CONFIG:Debug>>:-LTCG> $<$<NOT:$<CONFIG:Debug>>:-INCREMENTAL:NO>)
+    endif()
+else()
+    if (CMAKE_CXX_COMPILER_ID MATCHES "(Clang|IntelLLVM)" AND CMAKE_SYSTEM_PROCESSOR MATCHES "(x86|AMD64)")
+        set(TBB_COMMON_COMPILE_FLAGS ${TBB_COMMON_COMPILE_FLAGS} -mrtm -mwaitpkg)
+    endif()
+    set(TBB_IPO_COMPILE_FLAGS "")
+    set(TBB_IPO_LINK_FLAGS "")
+endif()
+
+set(TBB_OPENMP_FLAG /openmp)
--- a/deps/TBB/TBB.cmake
+++ b/deps/TBB/TBB.cmake
@@ -1,4 +1,6 @@
-if (FLATPAK AND "${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
+if (MSVC)
+    set(_patch_command ${CMAKE_COMMAND} -E copy ${CMAKE_CURRENT_LIST_DIR}/MSVC.cmake ./cmake/compilers/MSVC.cmake)
+elseif (FLATPAK AND "${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
    set(_patch_command ${CMAKE_COMMAND} -E copy ${CMAKE_CURRENT_LIST_DIR}/GNU.cmake ./cmake/compilers/GNU.cmake)
 else()
    set(_patch_command "")
@@ -13,6 +15,8 @@ orcaslicer_add_cmake_project(
        -DTBB_BUILD_SHARED=OFF
        -DTBB_BUILD_TESTS=OFF
        -DTBB_TEST=OFF
+        -DTBB_ENABLE_IPO=OFF
+        -DCMAKE_INTERPROCEDURAL_OPTIMIZATION=OFF
        -DCMAKE_POSITION_INDEPENDENT_CODE=ON
        -DCMAKE_DEBUG_POSTFIX=_debug
 )
--- a/deps/wxWidgets/0001-Clang-CL-fix.patch
+++ b/deps/wxWidgets/0001-Clang-CL-fix.patch
@@ -0,0 +1,28 @@
+---
+ build/cmake/wxWidgetsConfig.cmake.in | 10 +++++++++-
+ 1 file changed, 10 insertions(+), 1 deletion(-)
+
+diff --git a/build/cmake/wxWidgetsConfig.cmake.in b/build/cmake/wxWidgetsConfig.cmake.in
+index 1a83f36..70ad8a4 100644
+--- a/build/cmake/wxWidgetsConfig.cmake.in
+++ b/build/cmake/wxWidgetsConfig.cmake.in
+@@ -58,7 +58,16 @@ if(WIN32_MSVC_NAMING)
+     endif()
+ endif()
+ 
+-include("${CMAKE_CURRENT_LIST_DIR}${wxPLATFORM_LIB_DIR}/@PROJECT_NAME@Targets.cmake")
+if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND CMAKE_CXX_COMPILER_FRONTEND_VARIANT STREQUAL "MSVC")
+    if (CMAKE_GENERATOR_PLATFORM STREQUAL "ARM64" OR CMAKE_VS_PLATFORM_NAME STREQUAL "ARM64" OR CMAKE_SYSTEM_PROCESSOR MATCHES "^(ARM64|arm64|aarch64)$")
+        set(_wx_clang_msvc_lib_dir "vc_arm64_lib")
+    else()
+        set(_wx_clang_msvc_lib_dir "vc_x64_lib")
+    endif()
+    include("${CMAKE_CURRENT_LIST_DIR}${wxPLATFORM_LIB_DIR}/${_wx_clang_msvc_lib_dir}/@PROJECT_NAME@Targets.cmake")
+else()
+    include("${CMAKE_CURRENT_LIST_DIR}${wxPLATFORM_LIB_DIR}/@PROJECT_NAME@Targets.cmake")
+endif()
+ 
+ macro(wx_inherit_property source dest name)
+     # property name without _<CONFIG>
+--
+2.43.0
--- a/deps/wxWidgets/wxWidgets.cmake
+++ b/deps/wxWidgets/wxWidgets.cmake
@@ -28,6 +28,7 @@ orcaslicer_add_cmake_project(
    GIT_SHALLOW ON
    GIT_SUBMODULES 3rdparty/catch 3rdparty/pcre 3rdparty/libwebp
    DEPENDS ${PNG_PKG} ${ZLIB_PKG} ${EXPAT_PKG} ${JPEG_PKG}
+    PATCH_COMMAND git apply --verbose --ignore-space-change --whitespace=fix ${CMAKE_CURRENT_LIST_DIR}/0001-Clang-CL-fix.patch
    CMAKE_ARGS
        -DwxBUILD_PRECOMP=ON
        ${_wx_toolkit}
--- a/deps_src/clipper2/CMakeLists.txt
+++ b/deps_src/clipper2/CMakeLists.txt
@@ -37,7 +37,11 @@ target_include_directories(Clipper2
 )

 if (WIN32)
-  target_compile_options(Clipper2 PRIVATE /W4 /WX)
+  if (MSVC AND NOT CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+    target_compile_options(Clipper2 PRIVATE /W4 /WX)
+  elseif (CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND CMAKE_CXX_COMPILER_FRONTEND_VARIANT STREQUAL "MSVC")
+    target_compile_options(Clipper2 PRIVATE /W4)
+  endif()
 else()
  target_compile_options(Clipper2 PRIVATE -Wall -Wextra -Wpedantic -Werror)
  target_link_libraries(Clipper2 PUBLIC -lm)
--- a/deps_src/miniz/CMakeLists.txt
+++ b/deps_src/miniz/CMakeLists.txt
@@ -11,6 +11,8 @@ add_library(miniz_static STATIC

 if(${CMAKE_C_COMPILER_ID} STREQUAL "GNU")
    target_compile_definitions(miniz_static PRIVATE _GNU_SOURCE)
+elseif (CMAKE_C_COMPILER_ID STREQUAL "Clang" AND CMAKE_C_COMPILER_FRONTEND_VARIANT STREQUAL "MSVC")
+    target_compile_options(miniz_static PRIVATE /clang:-Wno-error=incompatible-pointer-types)
 endif()

 target_link_libraries(miniz INTERFACE miniz_static)
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -256,14 +256,6 @@ if (WIN32)
                VERBATIM
            )
        endforeach ()
-
-        if ("${CMAKE_BUILD_TYPE}" STREQUAL "Debug")
-            orcaslicer_copy_dlls(COPY_DLLS "Debug" "d" output_dlls_Debug)
-        elseif("${CMAKE_BUILD_TYPE}" STREQUAL "RelWithDebInfo")
-            orcaslicer_copy_dlls(COPY_DLLS "RelWithDebInfo" "" output_dlls_Release)
-        else()
-            orcaslicer_copy_dlls(COPY_DLLS "Release" "" output_dlls_Release)
-        endif()
    else ()
        file(TO_NATIVE_PATH "${CMAKE_CURRENT_BINARY_DIR}/resources" WIN_RESOURCES_SYMLINK)
        add_custom_command(TARGET OrcaSlicer POST_BUILD
@@ -279,6 +271,27 @@ if (WIN32)
        COMMENT "Copying Python runtime into the build tree"
        VERBATIM)

+    if (CMAKE_CONFIGURATION_TYPES)
+        # Multi-config generators (Visual Studio, Ninja Multi-Config): copy per config.
+        foreach (cfg ${CMAKE_CONFIGURATION_TYPES})
+            if ("${cfg}" STREQUAL "Debug")
+                orcaslicer_copy_dlls(COPY_DLLS "Debug" "d" output_dlls_Debug)
+            elseif("${cfg}" STREQUAL "RelWithDebInfo")
+                orcaslicer_copy_dlls(COPY_DLLS "RelWithDebInfo" "" output_dlls_RelWithDebInfo)
+            else()
+                orcaslicer_copy_dlls(COPY_DLLS "${cfg}" "" output_dlls_${cfg})
+            endif()
+        endforeach()
+    else()
+        # Single-config generators (Ninja): use CMAKE_BUILD_TYPE.
+        if ("${CMAKE_BUILD_TYPE}" STREQUAL "Debug")
+            orcaslicer_copy_dlls(COPY_DLLS "Debug" "d" output_dlls_Debug)
+        elseif("${CMAKE_BUILD_TYPE}" STREQUAL "RelWithDebInfo")
+            orcaslicer_copy_dlls(COPY_DLLS "RelWithDebInfo" "" output_dlls_RelWithDebInfo)
+        else()
+            orcaslicer_copy_dlls(COPY_DLLS "Release" "" output_dlls_Release)
+        endif()
+    endif()

 else ()
    if (APPLE AND NOT CMAKE_MACOSX_BUNDLE)
--- a/src/dev-utils/BaseException.cpp
+++ b/src/dev-utils/BaseException.cpp
@@ -69,7 +69,7 @@ void CBaseException::OutputString(LPCTSTR lpszFormat, ...)
 	//WriteConsole(GetStdHandle(STD_OUTPUT_HANDLE), szBuf, _tcslen(szBuf), NULL, NULL);

 	//output it to the current directory of binary
-	std::string output_str = textconv_helper::T2A_(szBuf);
+    std::string output_str = static_cast<const char*>(textconv_helper::T2A_(szBuf));
 	*output_file << output_str;
 	output_file->flush();
 }
--- a/src/libslic3r/BoundingBox.cpp
+++ b/src/libslic3r/BoundingBox.cpp
@@ -8,6 +8,8 @@
 namespace Slic3r {

 template BoundingBoxBase<Point, Points>::BoundingBoxBase(const Points &points);
+template void BoundingBoxBase<Point, Points>::construct<0, BoundingBox, Points::const_iterator>(BoundingBox&, Points::const_iterator, Points::const_iterator);
+template void BoundingBoxBase<Point, Points>::construct<1, BoundingBox, Points::const_iterator>(BoundingBox&, Points::const_iterator, Points::const_iterator);
 template BoundingBoxBase<Vec2d>::BoundingBoxBase(const std::vector<Vec2d> &points);

 template BoundingBox3Base<Vec3d>::BoundingBox3Base(const std::vector<Vec3d> &points);
--- a/src/slic3r/GUI/GUI_App.cpp
+++ b/src/slic3r/GUI/GUI_App.cpp
@@ -9849,7 +9849,7 @@ bool GUI_App::check_url_association(std::wstring url_prefix, std::wstring& reg_b
 {
    reg_bin = L"";
 #ifdef WIN32
-    wxRegKey key_full(wxRegKey::HKCU, "Software\\Classes\\" + url_prefix + "\\shell\\open\\command");
+    wxRegKey key_full(wxRegKey::HKCU, L"Software\\Classes\\" + url_prefix + L"\\shell\\open\\command");
    if (!key_full.Exists()) {
        return false;
    }
@@ -9875,8 +9875,8 @@ void GUI_App::associate_url(std::wstring url_prefix)

    wxString key_string = "\"" + wbinary + "\" \"%1\"";

-    wxRegKey key_first(wxRegKey::HKCU, "Software\\Classes\\" + url_prefix);
-    wxRegKey key_full(wxRegKey::HKCU, "Software\\Classes\\" + url_prefix + "\\shell\\open\\command");
+    wxRegKey key_first(wxRegKey::HKCU, L"Software\\Classes\\" + url_prefix);
+    wxRegKey key_full(wxRegKey::HKCU, L"Software\\Classes\\" + url_prefix + L"\\shell\\open\\command");
    if (!key_first.Exists()) {
        key_first.Create(false);
    }
@@ -9896,7 +9896,7 @@ void GUI_App::disassociate_url(std::wstring url_prefix)
 #ifdef WIN32
    if (is_running_in_msix())
        return;
-    wxRegKey key_full(wxRegKey::HKCU, "Software\\Classes\\" + url_prefix + "\\shell\\open\\command");
+    wxRegKey key_full(wxRegKey::HKCU, L"Software\\Classes\\" + url_prefix + L"\\shell\\open\\command");
    if (!key_full.Exists()) {
        return;
    }
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -5783,6 +5783,8 @@ private:
    bool show_warning_dialog { false };
 };

+Plater::~Plater() = default;
+
 const std::regex Plater::priv::pattern_bundle(".*[.](amf|amf[.]xml|zip[.]amf|3mf)", std::regex::icase);
 const std::regex Plater::priv::pattern_3mf(".*3mf", std::regex::icase);
 const std::regex Plater::priv::pattern_zip_amf(".*[.]zip[.]amf", std::regex::icase);
--- a/src/slic3r/GUI/Plater.hpp
+++ b/src/slic3r/GUI/Plater.hpp
@@ -290,7 +290,7 @@ public:
    Plater(const Plater &) = delete;
    Plater &operator=(Plater &&) = delete;
    Plater &operator=(const Plater &) = delete;
-    ~Plater() = default;
+    ~Plater();

    bool Show(bool show = true);

@@ -1020,4 +1020,4 @@ wxArrayString get_all_camera_view_type();
 } // namespace GUI
 } // namespace Slic3r

-#endif
+#endif
--- a/src/slic3r/GUI/PresetComboBoxes.hpp
+++ b/src/slic3r/GUI/PresetComboBoxes.hpp
@@ -39,7 +39,7 @@ public:
    PresetComboBox(wxWindow* parent, Preset::Type preset_type, const wxSize& size = wxDefaultSize, PresetBundle* preset_bundle = nullptr);
    ~PresetComboBox();

-	enum LabelItemType {
+	enum LabelItemType : std::size_t {
 		LABEL_ITEM_PHYSICAL_PRINTER = 0xffffff01,
        LABEL_ITEM_PRINTER_MODELS,
 		LABEL_ITEM_DISABLED,