From 32ff7aeefa9b1d2b0cc8046d5fd51ac6ce154215 Mon Sep 17 00:00:00 2001
From: Fariborz Jahanian <fjahanian@apple.com>
Date: Mon, 4 May 2009 23:27:20 +0000
Subject: [PATCH] Provide basic support for generation of objc2's
 objc_assign_global API when assigning to global objective-c object pointer.

llvm-svn: 70939
---
 clang/lib/CodeGen/CGExpr.cpp                 |  7 ++++++-
 clang/lib/CodeGen/CGValue.h                  | 11 ++++++++++-
 clang/test/CodeGenObjC/objc2-assign-global.m |  8 ++++++++
 3 files changed, 24 insertions(+), 2 deletions(-)
 create mode 100644 clang/test/CodeGenObjC/objc2-assign-global.m

diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index 2bcb362f186a..74d736490a24 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -442,7 +442,10 @@ void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst,
     else
       CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst);
 #endif
-    CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
+    if (Dst.isGlobalObjCRef())
+      CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst);
+    else
+      CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
     return;
   }
   
@@ -666,6 +669,8 @@ LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
     LValue LV = LValue::MakeAddr(CGM.GetAddrOfGlobalVar(VD),
                                  E->getType().getCVRQualifiers(),
                                  getContext().getObjCGCAttrKind(E->getType()));
+    if (LV.isObjCStrong())
+      LV.SetGlobalObjCRef(LV, true);
     return LV;
   } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(E->getDecl())) {
     return LValue::MakeAddr(CGM.GetAddrOfFunction(FD),
diff --git a/clang/lib/CodeGen/CGValue.h b/clang/lib/CodeGen/CGValue.h
index 66cb0037a136..5204c451666f 100644
--- a/clang/lib/CodeGen/CGValue.h
+++ b/clang/lib/CodeGen/CGValue.h
@@ -149,8 +149,12 @@ class LValue {
   // variable.
   bool NonGC: 1;
 
+  // Lvalue is a global reference of an objective-c object
+  bool GlobalObjCRef : 1;
+
   // objective-c's gc attributes
   unsigned ObjCType : 2;  
+
   
 
 private:
@@ -160,7 +164,7 @@ private:
     // FIXME: Convenient place to set objc flags to 0. This
     // should really be done in a user-defined constructor instead.
     R.ObjCType = None;
-    R.Ivar = R.NonGC = false;
+    R.Ivar = R.NonGC = R.GlobalObjCRef = false;
   }
   
 public:
@@ -180,12 +184,17 @@ public:
   
   bool isObjCIvar() const { return Ivar; }
   bool isNonGC () const { return NonGC; }
+  bool isGlobalObjCRef() const { return GlobalObjCRef; }
   bool isObjCWeak() const { return ObjCType == Weak; }
   bool isObjCStrong() const { return ObjCType == Strong; }
   
   static void SetObjCIvar(LValue& R, bool iValue) {
     R.Ivar = iValue;
   }
+
+  static void SetGlobalObjCRef(LValue& R, bool iValue) {
+    R.GlobalObjCRef = iValue;
+  }
   
   static void SetObjCNonGC(LValue& R, bool iValue) {
     R.NonGC = iValue;
diff --git a/clang/test/CodeGenObjC/objc2-assign-global.m b/clang/test/CodeGenObjC/objc2-assign-global.m
new file mode 100644
index 000000000000..ae407619093e
--- /dev/null
+++ b/clang/test/CodeGenObjC/objc2-assign-global.m
@@ -0,0 +1,8 @@
+// RUN: clang-cc -fnext-runtime -fobjc-gc -emit-llvm -o %t %s &&
+// RUN: grep -F '@objc_assign_global' %t  | count 2 &&
+// RUN: true
+id a;
+int main() {
+        a = 0;
+}
+