Reapply 81096, now with a fix. Spot the bug:

for (unsigned i = numargs; i < NumArgs; ++i)
        Args[0] = 0;

;)

llvm-svn: 81123

clang/lib/AST/ExprCXX.cpp

@@ -403,6 +403,8 @@ CXXConstructExpr::CXXConstructExpr(ASTContext &C, StmtClass SC, QualType T,
       Args = new (C) Stmt*[NumArgs];
       for (unsigned i = 0; i < numargs; ++i)
         Args[i] = args[i];
+      for (unsigned i = numargs; i < NumArgs; ++i)
+        Args[i] = 0;
     }
 }
 

clang/lib/Sema/SemaDeclCXX.cpp

@@ -2899,8 +2899,8 @@ bool Sema::InitializeVarWithConstructor(VarDecl *VD,
                                         QualType DeclInitType, 
                                         Expr **Exprs, unsigned NumExprs) {
   OwningExprResult TempResult = 
-    BuildCXXConstructExpr(/*FIXME: ConstructLoc*/ SourceLocation(),
-                          DeclInitType, Constructor, Exprs, NumExprs);
+    BuildCXXConstructExpr(VD->getLocation(), DeclInitType, Constructor, 
+                          Exprs, NumExprs);
   if (TempResult.isInvalid())
     return true;
   

clang/test/SemaTemplate/default-expr-arguments.cpp

@@ -20,7 +20,7 @@ void g() {
 }
 
 template<typename T> struct F {
-  F(T t = 10);
+  F(T t = 10); // expected-error{{cannot initialize 't' with an rvalue of type 'int'}}
   void f(T t = 10); // expected-error{{cannot initialize 't' with an rvalue of type 'int'}}
 };
 
@@ -34,6 +34,9 @@ void g2() {
 void g3(F<int> f, F<struct S> s) {
   f.f();
   s.f(); // expected-note{{in instantiation of default function argument expression for 'f<struct S>' required here}}
+  
+  F<int> f2;
+  F<S> s2; // expected-note{{in instantiation of default function argument expression for 'F<struct S>' required here}}
 }
 
 template<typename T> struct G {