Fix some build issues on Windows

Author: grynspan

stdlib/public/CommandLineSupport/CommandLine.cpp

@@ -124,25 +124,27 @@ char **_swift_stdlib_getUnsafeArgvArgc(int *outArgLen) {
     if (szBufferSize == 0) {
       swift::fatalError(0,
                         "Fatal error: Could not retrieve commandline "
-                        "arguments: %u\n",
-                        GetLastError());
+                        "argument %d: %lu\n",
+                        i, GetLastError());
       return nullptr;
     }
 
     char *buffer = static_cast<char *>(
         calloc(static_cast<size_t>(szBufferSize), sizeof(char)));
     if (buffer == nullptr) {
       swift::fatalError(0,
-                        "Fatal error: Could not allocate space for commandline"
-                        "arguments");
+                        "Fatal error: Could not allocate space for commandline "
+                        "argument %d: %d\n",
+                        i, errno);
       return nullptr;
     }
 
     if (!WideCharToMultiByte(CP_UTF8, WC_ERR_INVALID_CHARS, szArgList[i], -1,
                              buffer, szBufferSize, nullptr, nullptr)) {
       swift::fatalError(0,
                         "Fatal error: Conversion to UTF-8 failed for "
-                        "commandline arguments");
+                        "commandline argument %d: %lu\n",
+                        i, GetLastError());
       return nullptr;
     }
 

stdlib/public/Concurrency/Task.cpp

@@ -1265,23 +1265,21 @@ static void swift_task_asyncMainDrainQueueImpl() {
                        "swift_task_asyncMainDrainQueue");
 #else
 #if defined(_WIN32)
-  static void(FAR *pfndispatch_main)(void) = NULL;
-
-  if (pfndispatch_main)
-    return pfndispatch_main();
-
   HMODULE hModule = LoadLibraryW(L"dispatch.dll");
-  if (hModule == NULL)
-    swift_reportError(0, "unable to load dispatch.dll");
+  if (hModule == NULL) {
+    swift_Concurrency_fatalError(0,
+      "unable to load dispatch.dll: %lu", GetLastError());
+  }
 
-  pfndispatch_main =
-      reinterpret_cast<void (FAR *)(void)>(GetProcAddress(hModule,
-                                                          "dispatch_main"));
-  if (pfndispatch_main == NULL)
-    swift_reportError(0, "unable to locate dispatch_main in dispatch.dll");
+  auto pfndispatch_main = reinterpret_cast<void (FAR *)(void)>(
+    GetProcAddress(hModule, "dispatch_main"));
+  if (pfndispatch_main == NULL) {
+    swift_Concurrency_fatalError(0,
+      "unable to locate dispatch_main in dispatch.dll: %lu", GetLastError());
+  }
 
   pfndispatch_main();
-  exit(0);
+  swift_unreachable("Returned from dispatch_main()");
 #else
   // CFRunLoop is not available on non-Darwin targets.  Foundation has an
   // implementation, but CoreFoundation is not meant to be exposed.  We can only

stdlib/public/stubs/Random.cpp

@@ -70,7 +70,7 @@ void swift_stdlib_random(void *buf, __swift_size_t nbytes) {
                                     static_cast<ULONG>(nbytes),
                                     BCRYPT_USE_SYSTEM_PREFERRED_RNG);
   if (!BCRYPT_SUCCESS(status)) {
-    fatalError(0, "Fatal error: 0x%.8X in '%s'\n", status, __func__);
+    fatalError(0, "Fatal error: 0x%lX in '%s'\n", status, __func__);
   }
 }