Objective-C fast enumeration loop variables are not retained in ARC, but

they should still be officially __strong for the purposes of errors, 
block capture, etc.  Make a new bit on variables, isARCPseudoStrong(),
and set this for 'self' and these enumeration-loop variables.  Change
the code that was looking for the old patterns to look for this bit,
and change IR generation to find this bit and treat the resulting         
variable as __unsafe_unretained for the purposes of init/destroy in
the two places it can come up.

llvm-svn: 133243

1 files changed, 38 insertions, 4 deletions

diff --git a/clang/lib/CodeGen/CGDecl.cpp b/clang/lib/CodeGen/CGDecl.cpp
index daa37eea8f0..a79f031ec0a 100644
--- a/clang/lib/CodeGen/CGDecl.cpp
+++ b/clang/lib/CodeGen/CGDecl.cpp
@@ -562,6 +562,37 @@ void CodeGenFunction::EmitScalarInit(const Expr *init,
   EmitStoreOfScalar(value, lvalue);
 }
 
+/// EmitScalarInit - Initialize the given lvalue with the given object.
+void CodeGenFunction::EmitScalarInit(llvm::Value *init, LValue lvalue) {
+  Qualifiers::ObjCLifetime lifetime = lvalue.getObjCLifetime();
+  if (!lifetime)
+    return EmitStoreThroughLValue(RValue::get(init), lvalue, lvalue.getType());
+
+  switch (lifetime) {
+  case Qualifiers::OCL_None:
+    llvm_unreachable("present but none");
+
+  case Qualifiers::OCL_ExplicitNone:
+    // nothing to do
+    break;
+
+  case Qualifiers::OCL_Strong:
+    init = EmitARCRetain(lvalue.getType(), init);
+    break;
+
+  case Qualifiers::OCL_Weak:
+    // Initialize and then skip the primitive store.
+    EmitARCInitWeak(lvalue.getAddress(), init);
+    return;
+
+  case Qualifiers::OCL_Autoreleasing:
+    init = EmitARCRetainAutorelease(lvalue.getType(), init);
+    break;
+  }
+
+  EmitStoreOfScalar(init, lvalue);  
+}
+
 /// canEmitInitWithFewStoresAfterMemset - Decide whether we can emit the
 /// non-zero parts of the specified initializer with equal or fewer than
 /// NumStores scalar stores.
@@ -995,8 +1026,10 @@ void CodeGenFunction::EmitAutoVarCleanups(const AutoVarEmission &emission) {
 
   if (Qualifiers::ObjCLifetime lifetime
         = D.getType().getQualifiers().getObjCLifetime()) {
-    llvm::Value *loc = emission.getObjectAddress(*this);
-    EmitAutoVarWithLifetime(*this, D, loc, lifetime);
+    if (!D.isARCPseudoStrong()) {
+      llvm::Value *loc = emission.getObjectAddress(*this);
+      EmitAutoVarWithLifetime(*this, D, loc, lifetime);
+    }
   }
 
   // Handle the cleanup attribute.
@@ -1081,10 +1114,11 @@ void CodeGenFunction::EmitParmDecl(const VarDecl &D, llvm::Value *Arg,
 
       // 'self' is always formally __strong, but if this is not an
       // init method then we don't want to retain it.
-      if (lt == Qualifiers::OCL_Strong && qs.hasConst() &&
-          isa<ImplicitParamDecl>(D)) {
+      if (D.isARCPseudoStrong()) {
         const ObjCMethodDecl *method = cast<ObjCMethodDecl>(CurCodeDecl);
         assert(&D == method->getSelfDecl());
+        assert(lt == Qualifiers::OCL_Strong);
+        assert(qs.hasConst());
         assert(method->getMethodFamily() != OMF_init);
         (void) method;
         lt = Qualifiers::OCL_ExplicitNone;