Implement C++0x semantics for passing non-POD classes through varargs.

llvm-svn: 131792

1 files changed, 25 insertions, 5 deletions

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 5afd263ea13..6bccdaeb246 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -455,12 +455,32 @@ ExprResult Sema::DefaultVariadicArgumentPromotion(Expr *E, VariadicCallType CT,
           << E->getType() << CT))
     return ExprError();
 
-  if (!E->getType()->isPODType() &&
-      DiagRuntimeBehavior(E->getLocStart(), 0,
+  // C++ [expr.call]p7 prohibits non-POD types.
+  if (!E->getType()->isPODType()) {
+    // C++0x [expr.call]p7:
+    //   Passing a potentially-evaluated argument of class type (Clause 9) 
+    //   having a non-trivial copy constructor, a non-trivial move constructor,
+    //   or a non-trivial destructor, with no corresponding parameter, 
+    //   is conditionally-supported with implementation-defined semantics.
+    bool TrivialEnough = false;
+    if (getLangOptions().CPlusPlus0x && !E->getType()->isDependentType())  {
+      if (CXXRecordDecl *Record = E->getType()->getAsCXXRecordDecl()) {
+        if (Record->hasTrivialCopyConstructor() &&
+            Record->hasTrivialMoveConstructor() &&
+            Record->hasTrivialDestructor())
+          TrivialEnough = true;
+      }
+    }
+      
+    if (TrivialEnough) {
+      // Nothing to diagnose. This is okay.
+    } else if (DiagRuntimeBehavior(E->getLocStart(), 0,
                           PDiag(diag::warn_cannot_pass_non_pod_arg_to_vararg)
-                            << E->getType() << CT))
-    return ExprError();
-
+                            << getLangOptions().CPlusPlus0x << E->getType() 
+                            << CT))
+      return ExprError();
+  }
+  
   return Owned(E);
 }