Improves clang-cl build with Visual Studio (#809)

include/simdjson.h

@@ -8,6 +8,12 @@
  */
 
 #include "simdjson/compiler_check.h"
+#include "simdjson/common_defs.h"
+
+SIMDJSON_PUSH_DISABLE_WARNINGS
+#if defined(_MSC_VER) && defined(__clang__)
+SIMDJSON_DISABLE_GCC_WARNING(-Wmicrosoft-include)
+#endif
 
 // Public API
 #include "simdjson/simdjson_version.h"
@@ -29,4 +35,6 @@
 #include "simdjson/inline/padded_string.h"
 #include "simdjson/inline/parsedjson_iterator.h"
 
+SIMDJSON_POP_DISABLE_WARNINGS
+
 #endif // SIMDJSON_H

include/simdjson/common_defs.h

@@ -59,7 +59,7 @@ constexpr size_t DEFAULT_MAX_DEPTH = 1024;
 
 #define ISALIGNED_N(ptr, n) (((uintptr_t)(ptr) & ((n)-1)) == 0)
 
-#ifdef _MSC_VER
+#if defined(_MSC_VER) && !defined(__clang__)
 
   #define really_inline __forceinline
   #define never_inline __declspec(noinline)
@@ -119,7 +119,15 @@ constexpr size_t DEFAULT_MAX_DEPTH = 1024;
   #define SIMDJSON_DISABLE_DEPRECATED_WARNING SIMDJSON_DISABLE_GCC_WARNING(-Wdeprecated-declarations)
   #define SIMDJSON_POP_DISABLE_WARNINGS _Pragma("GCC diagnostic pop")
 
+  #if defined(_MSC_VER) && defined(__clang__)
+    #if SIMDJSON_USING_LIBRARY
+    #define SIMDJSON_DLLIMPORTEXPORT __declspec(dllimport)
+    #else
+    #define SIMDJSON_DLLIMPORTEXPORT __declspec(dllexport)
+    #endif
+  #else
     #define SIMDJSON_DLLIMPORTEXPORT
+  #endif
 
 #endif // MSC_VER
 

src/haswell/intrinsics.h

@@ -4,7 +4,14 @@
 #include "simdjson.h"
 
 #ifdef _MSC_VER
-#include <intrin.h> // visual studio
+// visual studio (or clang-cl)
+#include <intrin.h>
+#ifdef __clang__
+#include <bmiintrin.h>
+#include <lzcntintrin.h>
+#include <immintrin.h>
+#include <wmmintrin.h>
+#endif
 #else
 #include <x86intrin.h> // elsewhere
 #endif // _MSC_VER

src/simdjson.cpp

@@ -1,5 +1,9 @@
 #include "simdjson.h"
 
+#if defined(_MSC_VER) && defined(__clang__)
+SIMDJSON_DISABLE_GCC_WARNING(-Wmicrosoft-include)
+#endif
+
 /* used for http://dmalloc.com/ Dmalloc - Debug Malloc Library */
 #ifdef DMALLOC
 #include "dmalloc.h"