Implement initialization of a reference (C++ [dcl.init.ref]) as part
of copy initialization. Other pieces of the puzzle:

  - Try/Perform-ImplicitConversion now handles implicit conversions
    that don't involve references.
  - Try/Perform-CopyInitialization uses
    CheckSingleAssignmentConstraints for C. PerformCopyInitialization
    is now used for all argument passing and returning values from a
    function.
  - Diagnose errors with declaring references and const values without
    an initializer. (Uses a new Action callback, ActOnUninitializedDecl).
  
We do not yet have implicit conversion sequences for reference
binding, which means that we don't have any overloading support for
reference parameters yet.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@58353 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaStmt.cpp b/lib/Sema/SemaStmt.cpp
index f75758e..e7ccdda 100644
--- a/lib/Sema/SemaStmt.cpp
+++ b/lib/Sema/SemaStmt.cpp
@@ -693,7 +693,7 @@
   return new BreakStmt(BreakLoc);
 }
 
-/// ActOnBlockReturnStmt - Utilty routine to figure out block's return type.
+/// ActOnBlockReturnStmt - Utility routine to figure out block's return type.
 ///
 Action::StmtResult
 Sema::ActOnBlockReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) {
@@ -782,10 +782,11 @@
   // C99 6.8.6.4p3(136): The return statement is not an assignment. The 
   // overlap restriction of subclause 6.5.16.1 does not apply to the case of 
   // function return.  
-  AssignConvertType ConvTy = CheckSingleAssignmentConstraints(FnRetType, 
-                                                              RetValExp);
-  if (DiagnoseAssignmentResult(ConvTy, ReturnLoc, FnRetType,
-                               RetValType, RetValExp, "returning"))
+
+  // In C++ the return statement is handled via a copy initialization.
+  // the C version of which boils down to
+  // CheckSingleAssignmentConstraints.
+  if (PerformCopyInitialization(RetValExp, FnRetType, "returning"))
     return true;
   
   if (RetValExp) CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc);