Improve the C++ to be more correct for clang on Windows, still requiring the same disabled warnings as on *nix

Makefile

@@ -1,5 +1,5 @@
 GIT_SHA=$(shell git rev-parse --short HEAD)
-DISABLED_WARNINGS=-Wno-switch -Wno-pointer-sign -Wno-tautological-constant-out-of-range-compare -Wno-tautological-compare -Wno-macro-redefined -Wno-unused-value
+DISABLED_WARNINGS=-Wno-switch -Wno-macro-redefined -Wno-unused-value
 LDFLAGS=-pthread -ldl -lm -lstdc++
 CFLAGS=-std=c++14 -DGIT_SHA=\"$(GIT_SHA)\"
 CFLAGS:=$(CFLAGS) -DODIN_VERSION_RAW=\"dev-$(shell date +"%Y-%m")\"

src/gb/gb.h

@@ -2039,7 +2039,7 @@ typedef enum gbFileStandardType {
 	gbFileStandard_Count,
 } gbFileStandardType;
 
-GB_DEF gbFile *const gb_file_get_standard(gbFileStandardType std);
+GB_DEF gbFile *gb_file_get_standard(gbFileStandardType std);
 
 GB_DEF gbFileError gb_file_create        (gbFile *file, char const *filename);
 GB_DEF gbFileError gb_file_open          (gbFile *file, char const *filename);
@@ -3678,12 +3678,12 @@ gb_inline isize       gb_pointer_diff     (void const *begin, void const *end) {
 gb_inline void gb_zero_size(void *ptr, isize size) { gb_memset(ptr, 0, size); }
 
 
-#if defined(_MSC_VER)
+#if defined(_MSC_VER) && !defined(__clang__)
 #pragma intrinsic(__movsb)
 #endif
 
 gb_inline void *gb_memcopy(void *dest, void const *source, isize n) {
-#if defined(_MSC_VER)
+#if defined(_MSC_VER) && !defined(__clang__)
 	if (dest == NULL) {
 		return NULL;
 	}
@@ -4654,7 +4654,14 @@ gb_inline void gb_yield_thread(void) {
 
 gb_inline void gb_mfence(void) {
 #if defined(GB_SYSTEM_WINDOWS)
-	_ReadWriteBarrier();
+	#if defined(__clang__)
+	#pragma clang diagnostic push
+	#pragma clang diagnostic ignored "-Wdeprecated-declarations"
+		_ReadWriteBarrier();
+	#pragma clang diagnostic pop
+	#else
+		_ReadWriteBarrier();
+	#endif
 #elif defined(GB_SYSTEM_OSX)
 	#if defined(GB_CPU_X86)
 	__sync_synchronize();
@@ -4670,7 +4677,14 @@ gb_inline void gb_mfence(void) {
 
 gb_inline void gb_sfence(void) {
 #if defined(GB_SYSTEM_WINDOWS)
-	_WriteBarrier();
+	#if defined(__clang__)
+	#pragma clang diagnostic push
+	#pragma clang diagnostic ignored "-Wdeprecated-declarations"
+		_WriteBarrier();
+	#pragma clang diagnostic pop
+	#else
+		_WriteBarrier();
+	#endif
 #elif defined(GB_SYSTEM_OSX)
 	#if defined(GB_CPU_X86)
 	__asm__ volatile ("" : : : "memory");
@@ -4687,7 +4701,14 @@ gb_inline void gb_sfence(void) {
 
 gb_inline void gb_lfence(void) {
 #if defined(GB_SYSTEM_WINDOWS)
-	_ReadBarrier();
+	#if defined(__clang__)
+	#pragma clang diagnostic push
+	#pragma clang diagnostic ignored "-Wdeprecated-declarations"
+		_ReadBarrier();
+	#pragma clang diagnostic pop
+	#else
+		_ReadBarrier();
+	#endif
 #elif defined(GB_SYSTEM_OSX)
 	__asm__ volatile ("" : : : "memory");
 #elif defined(GB_CPU_X86)
@@ -8026,13 +8047,13 @@ gb_inline b32 gb_file_has_changed(gbFile *f) {
 }
 
 // TODO(bill): Is this a bad idea?
-gb_global b32    gb__std_file_set = false;
-gb_global gbFile gb__std_files[gbFileStandard_Count] = {{0}};
+gb_global b32    gb__std_file_set;
+gb_global gbFile gb__std_files[gbFileStandard_Count];
 
 
 #if defined(GB_SYSTEM_WINDOWS)
 
-gb_inline gbFile *const gb_file_get_standard(gbFileStandardType std) {
+gb_inline gbFile *gb_file_get_standard(gbFileStandardType std) {
 	if (!gb__std_file_set) {
 	#define GB__SET_STD_FILE(type, v) gb__std_files[type].fd.p = v; gb__std_files[type].ops = gbDefaultFileOperations
 		GB__SET_STD_FILE(gbFileStandard_Input,  GetStdHandle(STD_INPUT_HANDLE));
@@ -8082,7 +8103,7 @@ b32 gb_file_exists(char const *name) {
 
 #else // POSIX
 
-gb_inline gbFile *const gb_file_get_standard(gbFileStandardType std) {
+gb_inline gbFile *gb_file_get_standard(gbFileStandardType std) {
 	if (!gb__std_file_set) {
 	#define GB__SET_STD_FILE(type, v) gb__std_files[type].fd.i = v; gb__std_files[type].ops = gbDefaultFileOperations
 		GB__SET_STD_FILE(gbFileStandard_Input,  0);

src/microsoft_craziness.h

@@ -52,12 +52,12 @@ gb_global gbAllocator mc_allocator = heap_allocator();
 struct Find_Result {
     int windows_sdk_version;   // Zero if no Windows SDK found.
 
-    wchar_t *windows_sdk_root;
-    wchar_t *windows_sdk_um_library_path;
-    wchar_t *windows_sdk_ucrt_library_path;
+    wchar_t const *windows_sdk_root;
+    wchar_t const *windows_sdk_um_library_path;
+    wchar_t const *windows_sdk_ucrt_library_path;
 
-    wchar_t *vs_exe_path;
-    wchar_t *vs_library_path;
+    wchar_t const *vs_exe_path;
+    wchar_t const *vs_library_path;
 };
 
 struct Find_Result_Utf8 {
@@ -179,10 +179,10 @@ struct DECLSPEC_UUID("42843719-DB4C-46C2-8E7C-64F1816EFD5B") DECLSPEC_NOVTABLE I
 
 struct Version_Data {
     i32 best_version[4];  // For Windows 8 versions, only two of these numbers are used.
-    wchar_t *best_name;
+    wchar_t const *best_name;
 };
 
-bool os_file_exists(wchar_t *name) {
+bool os_file_exists(wchar_t const *name) {
     // @Robustness: What flags do we really want to check here?
 
     auto attrib = GetFileAttributesW(name);
@@ -192,7 +192,7 @@ bool os_file_exists(wchar_t *name) {
     return true;
 }
 
-wchar_t *concat(wchar_t *a, wchar_t *b, wchar_t *c = nullptr, wchar_t *d = nullptr) {
+wchar_t *concat(wchar_t const *a, wchar_t const *b, wchar_t const *c = nullptr, wchar_t const *d = nullptr) {
     // Concatenate up to 4 wide strings together. Allocated with malloc.
     // If you don't like that, use a programming language that actually
     // helps you with using custom allocators. Or just edit the code.
@@ -214,8 +214,8 @@ wchar_t *concat(wchar_t *a, wchar_t *b, wchar_t *c = nullptr, wchar_t *d = nullp
     return result;
 }
 
-typedef void (*Visit_Proc_W)(wchar_t *short_name, wchar_t *full_name, Version_Data *data);
-bool visit_files_w(wchar_t *dir_name, Version_Data *data, Visit_Proc_W proc) {
+typedef void (*Visit_Proc_W)(wchar_t const *short_name, wchar_t const *full_name, Version_Data *data);
+bool visit_files_w(wchar_t const *dir_name, Version_Data *data, Visit_Proc_W proc) {
 
     // Visit everything in one folder (non-recursively). If it's a directory
     // that doesn't start with ".", call the visit proc on it. The visit proc
@@ -246,7 +246,7 @@ bool visit_files_w(wchar_t *dir_name, Version_Data *data, Visit_Proc_W proc) {
 }
 
 
-wchar_t *find_windows_kit_root(HKEY key, wchar_t *version) {
+wchar_t *find_windows_kit_root(HKEY key, wchar_t const *version) {
     // Given a key to an already opened registry entry,
     // get the value stored under the 'version' subkey.
     // If that's not the right terminology, hey, I never do registry stuff.
@@ -272,7 +272,7 @@ wchar_t *find_windows_kit_root(HKEY key, wchar_t *version) {
     return value;
 }
 
-void win10_best(wchar_t *short_name, wchar_t *full_name, Version_Data *data) {
+void win10_best(wchar_t const *short_name, wchar_t const *full_name, Version_Data *data) {
     // Find the Windows 10 subdirectory with the highest version number.
 
     int i0, i1, i2, i3;
@@ -292,7 +292,7 @@ void win10_best(wchar_t *short_name, wchar_t *full_name, Version_Data *data) {
 
     // we have to copy_string and free here because visit_files free's the full_name string
     // after we execute this function, so Win*_Data would contain an invalid pointer.
-    if (data->best_name) free(data->best_name);
+    if (data->best_name) free((void *)data->best_name);
     data->best_name = _wcsdup(full_name);
 
     if (data->best_name) {
@@ -303,7 +303,7 @@ void win10_best(wchar_t *short_name, wchar_t *full_name, Version_Data *data) {
     }
 }
 
-void win8_best(wchar_t *short_name, wchar_t *full_name, Version_Data *data) {
+void win8_best(wchar_t const *short_name, wchar_t const *full_name, Version_Data *data) {
     // Find the Windows 8 subdirectory with the highest version number.
 
     int i0, i1;
@@ -317,7 +317,7 @@ void win8_best(wchar_t *short_name, wchar_t *full_name, Version_Data *data) {
 
     // we have to copy_string and free here because visit_files free's the full_name string
     // after we execute this function, so Win*_Data would contain an invalid pointer.
-    if (data->best_name) free(data->best_name);
+    if (data->best_name) free((void *)data->best_name);
     data->best_name = _wcsdup(full_name);
 
     if (data->best_name) {
@@ -502,11 +502,11 @@ bool find_visual_studio_by_fighting_through_microsoft_craziness(Find_Result *res
         defer (RegCloseKey(vs7_key));
 
         // Hardcoded search for 4 prior Visual Studio versions. Is there something better to do here?
-        wchar_t *versions[] = { L"14.0", L"13.0",  L"12.0", L"11.0", L"10.0", L"9.0", };
+        wchar_t const *versions[] = { L"14.0", L"13.0",  L"12.0", L"11.0", L"10.0", L"9.0", };
         const int NUM_VERSIONS = sizeof(versions) / sizeof(versions[0]);
 
         for (int i = 0; i < NUM_VERSIONS; i++) {
-            wchar_t *v = versions[i];
+            wchar_t const *v = versions[i];
 
             DWORD dw_type;
             DWORD cb_data;
@@ -589,7 +589,7 @@ Find_Result find_visual_studio_and_windows_sdk() {
     return result;
 }
 
-String mc_wstring_to_string(wchar_t *str) {
+String mc_wstring_to_string(wchar_t const *str) {
     return string16_to_string(mc_allocator, make_string16_c(str));
 }