[ubsan] Enable -fsanitize=vptr on Apple devices and simulators

It seems like an oversight that this check was not always enabled for
on-device or device simulator targets.

Differential Revision: https://reviews.llvm.org/D51239

llvm-svn: 340849

clang/lib/Driver/ToolChains/Darwin.cpp

@@ -2258,9 +2258,15 @@ SanitizerMask Darwin::getSupportedSanitizers() const {
   Res |= SanitizerKind::Fuzzer;
   Res |= SanitizerKind::FuzzerNoLink;
   Res |= SanitizerKind::Function;
+
+  // Prior to 10.9, macOS shipped a version of the C++ standard library without
+  // C++11 support. The same is true of iOS prior to version 5. These OS'es are
+  // incompatible with -fsanitize=vptr.
+  if (!(isTargetMacOS() && isMacosxVersionLT(10, 9))
+      && !(isTargetIPhoneOS() && isIPhoneOSVersionLT(5, 0)))
+    Res |= SanitizerKind::Vptr;
+
   if (isTargetMacOS()) {
-    if (!isMacosxVersionLT(10, 9))
-      Res |= SanitizerKind::Vptr;
     if (IsX86_64)
       Res |= SanitizerKind::Thread;
   } else if (isTargetIOSSimulator() || isTargetTvOSSimulator()) {

clang/test/Driver/fsanitize.c

@@ -423,6 +423,15 @@
 // RUN: %clang -target x86_64-apple-darwin10 -mmacosx-version-min=10.8 -fsanitize=vptr %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-VPTR-DARWIN-OLD
 // CHECK-VPTR-DARWIN-OLD: unsupported option '-fsanitize=vptr' for target 'x86_64-apple-darwin10'
 
+// RUN: %clang -target arm-apple-ios4 -fsanitize=vptr %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-VPTR-IOS-OLD
+// CHECK-VPTR-IOS-OLD: unsupported option '-fsanitize=vptr' for target 'arm-apple-ios4'
+
+// RUN: %clang -target aarch64-apple-darwin15.0.0 -fsanitize=vptr %s -### 2>&1
+// OK
+
+// RUN: %clang -target x86_64-apple-darwin15.0.0-simulator -fsanitize=vptr %s -### 2>&1
+// OK
+
 // RUN: %clang -target x86_64-apple-darwin10 -mmacosx-version-min=10.9 -fsanitize=alignment,vptr %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-VPTR-DARWIN-NEW
 // CHECK-VPTR-DARWIN-NEW: -fsanitize=alignment,vptr