1 files changed, 43 insertions, 0 deletions
diff --git a/lib/ARCMigrate/ARCMT.cpp b/lib/ARCMigrate/ARCMT.cpp
index b7828c54cd..6e1b0e535b 100644
--- a/lib/ARCMigrate/ARCMT.cpp
+++ b/lib/ARCMigrate/ARCMT.cpp
@@ -117,11 +117,54 @@ public:
 
 } // end anonymous namespace
 
+static inline StringRef SimulatorVersionDefineName() {
+  return "__IPHONE_OS_VERSION_MIN_REQUIRED=";
+}
+
+/// \brief Parse the simulator version define:
+/// __IPHONE_OS_VERSION_MIN_REQUIRED=([0-9])([0-9][0-9])([0-9][0-9])
+// and return the grouped values as integers, e.g:
+//   __IPHONE_OS_VERSION_MIN_REQUIRED=40201
+// will return Major=4, Minor=2, Micro=1.
+static bool GetVersionFromSimulatorDefine(StringRef define,
+                                          unsigned &Major, unsigned &Minor,
+                                          unsigned &Micro) {
+  assert(define.startswith(SimulatorVersionDefineName()));
+  StringRef name, version;
+  llvm::tie(name, version) = define.split('=');
+  if (version.empty())
+    return false;
+  std::string verstr = version.str();
+  char *end;
+  unsigned num = (unsigned) strtol(verstr.c_str(), &end, 10);
+  if (*end != '\0')
+    return false;
+  Major = num / 10000;
+  num = num % 10000;
+  Minor = num / 100;
+  Micro = num % 100;
+  return true;
+}
+
 static bool HasARCRuntime(CompilerInvocation &origCI) {
   // This duplicates some functionality from Darwin::AddDeploymentTarget
   // but this function is well defined, so keep it decoupled from the driver
   // and avoid unrelated complications.
 
+  for (unsigned i = 0, e = origCI.getPreprocessorOpts().Macros.size();
+         i != e; ++i) {
+    StringRef define = origCI.getPreprocessorOpts().Macros[i].first;
+    bool isUndef = origCI.getPreprocessorOpts().Macros[i].second;
+    if (isUndef)
+      continue;
+    if (!define.startswith(SimulatorVersionDefineName()))
+      continue;
+    unsigned Major = 0, Minor = 0, Micro = 0;
+    if (GetVersionFromSimulatorDefine(define, Major, Minor, Micro) &&
+        Major < 10 && Minor < 100 && Micro < 100)
+      return Major >= 5;
+  }
+
   llvm::Triple triple(origCI.getTargetOpts().Triple);
 
   if (triple.getOS() == llvm::Triple::IOS)