Merge pull request swiftlang#68099 from hjyamauchi/abort

Fix a fatal error not-terminating issue in Windows

Author: compnerd

stdlib/public/runtime/Errors.cpp

@@ -471,3 +471,18 @@ void swift::swift_abortDisabledUnicodeSupport() {
                     "Unicode normalization data is disabled on this platform");
 
 }
+
+#if defined(_WIN32)
+// On Windows, exceptions may be swallowed in some cases and the
+// process may not terminate as expected on crashes. For example,
+// illegal instructions used by llvm.trap. Disable the exception
+// swallowing so that the error handling works as expected.
+__attribute__((__constructor__))
+static void ConfigureExceptionPolicy() {
+  BOOL Suppress = FALSE;
+  SetUserObjectInformationA(GetCurrentProcess(),
+                            UOI_TIMERPROC_EXCEPTION_SUPPRESSION,
+                            &Suppress, sizeof(Suppress));
+}
+
+#endif

test/stdlib/WinExceptionSuppression.swift

@@ -0,0 +1,24 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-build-swift -module-name=main %s -o %t/a.out
+// RUN: %target-codesign %t/a.out
+// RUN: not %target-run %t/a.out 2>&1 | %FileCheck %s
+// REQUIRES: executable_test
+// REQUIRES: OS=windows-msvc
+
+// Check that a fatal error terminates the process and it appears only once.
+// CHECK: Fatal error
+// CHECK-NOT: Fatal error
+
+import WinSDK
+
+private var timerID: UINT_PTR = 1
+let doWork: TIMERPROC = { (_: HWND?, _: UINT, _: UINT_PTR, _: DWORD) in
+    fatalError("oops")
+    timerID = SetTimer(nil, timerID, UInt32(0), doWork)
+}
+var msg: MSG = .init()
+timerID = SetTimer(nil, timerID, UInt32(0), doWork)
+while (GetMessageA(&msg, nil, 0, 0)) {
+  TranslateMessage(&msg);
+  DispatchMessageA(&msg);
+}