Can build with (original llvm) clang-cl on windows

CMakeLists.txt

@@ -52,8 +52,14 @@ if (SLIC3R_GUI)
     add_definitions(-DSLIC3R_GUI)
 endif ()
 
+if (MSVC AND CMAKE_CXX_COMPILER_ID STREQUAL Clang)
+    set(IS_CLANG_CL TRUE)
+else ()
+    set(IS_CLANG_CL FALSE)
+endif ()
+
 if (MSVC)
-    if (SLIC3R_MSVC_COMPILE_PARALLEL)
+    if (SLIC3R_MSVC_COMPILE_PARALLEL AND NOT IS_CLANG_CL)
 	   add_compile_options(/MP)
     endif ()
     # /bigobj (Increase Number of Sections in .Obj file)
@@ -148,7 +154,7 @@ if (CMAKE_COMPILER_IS_GNUCC OR CMAKE_COMPILER_IS_GNUXX)
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fext-numeric-literals" )
 endif()
 
-if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU" OR "${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
+if (NOT MSVC AND ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU" OR "${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang"))
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall" )
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-reorder" )
 
@@ -168,7 +174,6 @@ if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU" OR "${CMAKE_CXX_COMPILER_ID}" MATC
         add_compile_options(-Wno-unknown-pragmas)
     endif()
 
-
     if (SLIC3R_ASAN)
         add_compile_options(-fsanitize=address -fno-omit-frame-pointer)
         set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -fsanitize=address")

cmake/modules/PrecompiledHeader.cmake

@@ -105,6 +105,9 @@ function(add_precompiled_header _target _input)
   cmake_parse_arguments(_PCH "FORCEINCLUDE" "SOURCE_CXX;SOURCE_C" "" ${ARGN})
 
   get_filename_component(_input_we ${_input} NAME_WE)
+  get_filename_component(_input_full ${_input} ABSOLUTE)
+  file(TO_NATIVE_PATH "${_input_full}" _input_fullpath)
+
   if(NOT _PCH_SOURCE_CXX)
     set(_PCH_SOURCE_CXX "${_input_we}.cpp")
   endif()
@@ -138,16 +141,16 @@ function(add_precompiled_header _target _input)
           set_source_files_properties("${_source}" PROPERTIES OBJECT_OUTPUTS "${_pch_c_pch}")
         else()
           if(_source MATCHES \\.\(cpp|cxx|cc\)$)
-            set(_pch_compile_flags "${_pch_compile_flags} \"/Fp${_pch_cxx_pch}\" \"/Yu${_input}\"")
+            set(_pch_compile_flags "${_pch_compile_flags} \"/Fp${_pch_cxx_pch}\" \"/Yu${_input_fullpath}\"")
             set(_pch_source_cxx_needed TRUE)
             set_source_files_properties("${_source}" PROPERTIES OBJECT_DEPENDS "${_pch_cxx_pch}")
           else()
-            set(_pch_compile_flags "${_pch_compile_flags} \"/Fp${_pch_c_pch}\" \"/Yu${_input}\"")
+            set(_pch_compile_flags "${_pch_compile_flags} \"/Fp${_pch_c_pch}\" \"/Yu${_input_fullpath}\"")
             set(_pch_source_c_needed TRUE)
             set_source_files_properties("${_source}" PROPERTIES OBJECT_DEPENDS "${_pch_c_pch}")
           endif()
           if(_PCH_FORCEINCLUDE)
-            set(_pch_compile_flags "${_pch_compile_flags} /FI${_input}")
+            set(_pch_compile_flags "${_pch_compile_flags} /FI${_input_fullpath}")
           endif(_PCH_FORCEINCLUDE)
         endif()
 

deps/deps-windows.cmake

@@ -19,6 +19,10 @@ else ()
     message(FATAL_ERROR "Unsupported MSVC version")
 endif ()
 
+if (CMAKE_CXX_COMPILER_ID STREQUAL Clang)
+    set(DEP_BOOST_TOOLSET "clang-win")
+endif ()
+
 if (${DEPS_BITS} EQUAL 32)
     set(DEP_MSVC_GEN "Visual Studio ${DEP_VS_VER}")
     set(DEP_PLATFORM "Win32")

src/avrdude/windows/unistd.h

@@ -63,10 +63,15 @@ extern "C" {
 #define STDOUT_FILENO 1
 #define STDERR_FILENO 2
 
+#ifdef _MSC_VER
+#include <stdint.h>
+struct timezone;
+struct timeval;
+#else
 #ifndef __cplusplus
 /* should be in some equivalent to <sys/types.h> */
 typedef __int8            int8_t;
-typedef __int16           int16_t; 
+typedef __int16           int16_t;
 typedef __int32           int32_t;
 typedef __int64           int64_t;
 typedef unsigned __int8   uint8_t;
@@ -74,6 +79,7 @@ typedef unsigned __int16  uint16_t;
 typedef unsigned __int32  uint32_t;
 typedef unsigned __int64  uint64_t;
 #endif
+#endif
 
 
 int usleep(unsigned usec);

src/libnest2d/tests/test.cpp

@@ -7,6 +7,10 @@
 #include "../tools/svgtools.hpp"
 #include <libnest2d/utils/rotcalipers.hpp>
 
+#if defined(_MSC_VER) && defined(__clang__)
+#define BOOST_NO_CXX17_HDR_STRING_VIEW
+#endif
+
 #include "boost/multiprecision/integer.hpp"
 #include "boost/rational.hpp"
 

src/libslic3r/Arrange.cpp

@@ -12,6 +12,11 @@
 #include <ClipperUtils.hpp>
 
 #include <boost/geometry/index/rtree.hpp>
+
+#if defined(_MSC_VER) && defined(__clang__)
+#define BOOST_NO_CXX17_HDR_STRING_VIEW
+#endif
+
 #include <boost/multiprecision/integer.hpp>
 #include <boost/rational.hpp>
 

src/libslic3r/MinAreaBoundingBox.cpp

@@ -1,6 +1,11 @@
 #include "MinAreaBoundingBox.hpp"
 
 #include <libslic3r/ExPolygon.hpp>
+
+#if defined(_MSC_VER) && defined(__clang__)
+#define BOOST_NO_CXX17_HDR_STRING_VIEW
+#endif
+
 #include <boost/rational.hpp>
 
 #include <libslic3r/Int128.hpp>

src/slic3r/GUI/GUI_Utils.cpp

@@ -62,7 +62,7 @@ template<class F> typename F::FN winapi_get_function(const wchar_t *dll, const c
     static HINSTANCE dll_handle = LoadLibraryExW(dll, nullptr, 0);
 
     if (dll_handle == nullptr) { return nullptr; }
-    return (F::FN)GetProcAddress(dll_handle, fn_name);
+    return (typename F::FN)GetProcAddress(dll_handle, fn_name);
 }
 #endif