From a422cd0ed4da8cb5a172498f29bb02065707c6ce Mon Sep 17 00:00:00 2001
From: David Chisnall <csdavec@swan.ac.uk>
Date: Wed, 4 Jul 2012 10:37:03 +0000
Subject: [PATCH] A few more cleanups for the GNU family of ObjC runtimes.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159708 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/clang/Basic/ObjCRuntime.h | 7 ++-----
 lib/Basic/ObjCRuntime.cpp         | 5 ++++-
 lib/Driver/Tools.cpp              | 7 ++++++-
 3 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/include/clang/Basic/ObjCRuntime.h b/include/clang/Basic/ObjCRuntime.h
index 9212a8bf95..10922ed5af 100644
--- a/include/clang/Basic/ObjCRuntime.h
+++ b/include/clang/Basic/ObjCRuntime.h
@@ -116,11 +116,8 @@ public:
     case MacOSX: return getVersion() >= VersionTuple(10, 7);
     case iOS: return getVersion() >= VersionTuple(5);
 
-    // This is really a lie, because some implementations and versions
-    // of the runtime do not support ARC.  Probably -fgnu-runtime
-    // should imply a "maximal" runtime or something?
-    case GCC: return true;
-    case GNUstep: return true;
+    case GCC: return false;
+    case GNUstep: return getVersion() >= VersionTuple(1, 6);
     }
     llvm_unreachable("bad kind");
   }
diff --git a/lib/Basic/ObjCRuntime.cpp b/lib/Basic/ObjCRuntime.cpp
index 0f30bfaa2c..f52677b512 100644
--- a/lib/Basic/ObjCRuntime.cpp
+++ b/lib/Basic/ObjCRuntime.cpp
@@ -54,6 +54,7 @@ bool ObjCRuntime::tryParse(StringRef input) {
   // Everything prior to that must be a valid string name.
   Kind kind;
   StringRef runtimeName = input.substr(0, dash);
+  Version = VersionTuple(0);
   if (runtimeName == "macosx") {
     kind = ObjCRuntime::MacOSX;
   } else if (runtimeName == "macosx-fragile") {
@@ -61,6 +62,9 @@ bool ObjCRuntime::tryParse(StringRef input) {
   } else if (runtimeName == "ios") {
     kind = ObjCRuntime::iOS;
   } else if (runtimeName == "gnustep") {
+    // If no version is specified then default to the most recent one that we
+    // know about.
+    Version = VersionTuple(1, 6);
     kind = ObjCRuntime::GNUstep;
   } else if (runtimeName == "gcc") {
     kind = ObjCRuntime::GCC;
@@ -69,7 +73,6 @@ bool ObjCRuntime::tryParse(StringRef input) {
   }
   TheKind = kind;
   
-  Version = VersionTuple(0);
   if (dash != StringRef::npos) {
     StringRef verString = input.substr(dash + 1);
     if (Version.tryParse(verString)) 
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index a558c1ff96..3b15d123cc 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -2934,7 +2934,12 @@ ObjCRuntime Clang::AddObjCRuntimeArgs(const ArgList &args,
   // -fgnu-runtime
   } else {
     assert(runtimeArg->getOption().matches(options::OPT_fgnu_runtime));
-    runtime = ObjCRuntime(ObjCRuntime::GCC, VersionTuple());
+    // Legacy behaviour is to target the gnustep runtime if we are i
+    // non-fragile mode or the GCC runtime in fragile mode.
+    if (isNonFragile)
+      runtime = ObjCRuntime(ObjCRuntime::GNUstep, VersionTuple());
+    else
+      runtime = ObjCRuntime(ObjCRuntime::GCC, VersionTuple());
   }
 
   cmdArgs.push_back(args.MakeArgString(
-- 
2.40.0