Merge pull request #1889 from apple/PR-69727650

Handle unknown OSes in DarwinTargetInfo::getExnObjectAlignment

Author: ahatanaka

clang/lib/Basic/Targets/OSTargets.h

@@ -154,7 +154,8 @@ class LLVM_LIBRARY_VISIBILITY DarwinTargetInfo : public OSTargetInfo<Target> {
       MinVersion = llvm::VersionTuple(5U);
       break;
     default:
-      llvm_unreachable("Unexpected OS");
+      // Conservatively return 8 bytes if OS is unknown.
+      return 64;
     }
 
     unsigned Major, Minor, Micro;

clang/test/SemaCXX/warn-overaligned-type-thrown.cpp

@@ -3,6 +3,7 @@
 // RUN: %clang_cc1 -triple arm64-apple-tvos10 -verify -fsyntax-only -std=c++11 -fcxx-exceptions -fexceptions -DUNDERALIGNED %s
 // RUN: %clang_cc1 -triple arm64-apple-watchos4 -verify -fsyntax-only -std=c++11 -fcxx-exceptions -fexceptions -DUNDERALIGNED %s
 // RUN: %clang_cc1 -triple arm-linux-gnueabi -verify -fsyntax-only -std=c++11 -fcxx-exceptions -fexceptions  -DUNDERALIGNED %s
+// RUN: %clang_cc1 -triple thumbv7em-apple-unknown-macho -verify -fsyntax-only -std=c++11 -fcxx-exceptions -fexceptions -DUNDERALIGNED %s
 // RUN: %clang_cc1 -triple x86_64-apple-macosx10.14 -verify -fsyntax-only -std=c++11 -fcxx-exceptions -fexceptions %s
 // RUN: %clang_cc1 -triple arm64-apple-ios12 -verify -fsyntax-only -std=c++11 -fcxx-exceptions -fexceptions %s
 // RUN: %clang_cc1 -triple arm64-apple-tvos12 -verify -fsyntax-only -std=c++11 -fcxx-exceptions -fexceptions %s