Update darwin SDK version parsing to support OSX and simulator

This re-commits r226005 with a tweak. The origin attempt failed because
Darwin bot sets up SDKROOT and clang can deduce SDK version from them
after this patch. That broke many driver tests due to the change of
deployment target version. Now the tests should not complain after
r240574.

llvm-svn: 240619

1 files changed, 23 insertions, 8 deletions

diff --git a/clang/lib/Driver/ToolChains.cpp b/clang/lib/Driver/ToolChains.cpp
index e107126d98b..4c69716dc14 100644
--- a/clang/lib/Driver/ToolChains.cpp
+++ b/clang/lib/Driver/ToolChains.cpp
@@ -463,16 +463,31 @@ void Darwin::AddDeploymentTarget(DerivedArgList &Args) const {
     if (char *env = ::getenv("IPHONEOS_DEPLOYMENT_TARGET"))
       iOSTarget = env;
 
-    // If no '-miphoneos-version-min' specified on the command line and
-    // IPHONEOS_DEPLOYMENT_TARGET is not defined, see if we can set the default
-    // based on -isysroot.
-    if (iOSTarget.empty()) {
+    // If there is no command-line argument to specify the Target version and
+    // no environment variable defined, see if we can set the default based
+    // on -isysroot.
+    if (iOSTarget.empty() && OSXTarget.empty() &&
+        Args.hasArg(options::OPT_isysroot)) {
       if (const Arg *A = Args.getLastArg(options::OPT_isysroot)) {
-        StringRef first, second;
         StringRef isysroot = A->getValue();
-        std::tie(first, second) = isysroot.split(StringRef("SDKs/iPhoneOS"));
-        if (second != "")
-          iOSTarget = second.substr(0,3);
+        // Assume SDK has path: SOME_PATH/SDKs/PlatformXX.YY.sdk
+        size_t BeginSDK = isysroot.rfind("SDKs/");
+        size_t EndSDK = isysroot.rfind(".sdk");
+        if (BeginSDK != StringRef::npos && EndSDK != StringRef::npos) {
+          StringRef SDK = isysroot.slice(BeginSDK + 5, EndSDK);
+          // Slice the version number out.
+          // Version number is between the first and the last number.
+          size_t StartVer = SDK.find_first_of("0123456789");
+          size_t EndVer = SDK.find_last_of("0123456789");
+          if (StartVer != StringRef::npos && EndVer > StartVer) {
+            StringRef Version = SDK.slice(StartVer, EndVer + 1);
+            if (SDK.startswith("iPhoneOS") ||
+                SDK.startswith("iPhoneSimulator"))
+              iOSTarget = Version;
+            else if (SDK.startswith("MacOSX"))
+              OSXTarget = Version;
+          }
+        }
       }
     }