dll: support /NODEFAULTLIB builds

src/dll/library.c

@@ -21,3 +21,11 @@ BOOL WINAPI DllMain(HINSTANCE Instance, DWORD Reason, PVOID Reserved)
 
     return TRUE;
 }
+
+/* see comments in library.h */
+#if defined(WINFSP_DLL_NODEFAULTLIB)
+BOOL WINAPI _DllMainCRTStartup(HINSTANCE Instance, DWORD Reason, PVOID Reserved)
+{
+    return DllMain(Instance, Reason, Reserved);
+}
+#endif

src/dll/library.h

@@ -41,4 +41,35 @@ static inline VOID MemFree(PVOID Pointer)
         HeapFree(ProcessHeap, 0, Pointer);
 }
 
+/*
+ * Define WINFSP_DLL_NODEFAULTLIB to eliminate dependency on the MSVCRT libraries.
+ *
+ * For this to work the following project settings must be set:
+ * - "C/C++ > General > SDL checks" must be empty (not "Yes" or "No").
+ * - "C/C++ > Code Generation > Basic Runtime Checks" must be set to "Default"
+ * - "C/C++ > Code Generation > Security Check" must be disabled (/GS-).
+ * - "Linker > Input > Ignore All Default Libraries" must be "Yes".
+ */
+#if defined(WINFSP_DLL_NODEFAULTLIB)
+#undef RtlFillMemory
+#undef RtlMoveMemory
+NTSYSAPI VOID NTAPI RtlFillMemory(VOID *Destination, DWORD Length, BYTE Fill);
+NTSYSAPI VOID NTAPI RtlMoveMemory(VOID *Destination, CONST VOID *Source, DWORD Length);
+
+#pragma function(memcpy)
+#pragma function(memset)
+static inline
+void *memcpy(void *dst, const void *src, size_t siz)
+{
+    RtlMoveMemory(dst, src, (DWORD)siz);
+    return dst;
+}
+static inline
+void *memset(void *dst, int val, size_t siz)
+{
+    RtlFillMemory(dst, (DWORD)siz, val);
+    return dst;
+}
+#endif
+
 #endif

src/dll/loop.c

@@ -163,7 +163,8 @@ FSP_API NTSTATUS FspProduceResponse(FSP_FILE_SYSTEM *FileSystem,
 FSP_API NTSTATUS FspProduceResponseWithStatus(FSP_FILE_SYSTEM *FileSystem,
     FSP_FSCTL_TRANSACT_REQ *Request, NTSTATUS Result)
 {
-    FSP_FSCTL_TRANSACT_RSP Response = { 0 };
+    FSP_FSCTL_TRANSACT_RSP Response;
+    memset(&Response, 0, sizeof Response);
     Response.Size = sizeof Response;
     Response.Kind = Request->Kind;
     Response.Hint = Request->Hint;