Keep track of when declarations are "used" according to C and

C++. This logic is required to trigger implicit instantiation of
function templates and member functions of class templates, which will
be implemented separately.

This commit includes support for -Wunused-parameter, printing warnings
for named parameters that are not used within a function/Objective-C
method/block. Fixes <rdar://problem/6505209>.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@73797 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 11 insertions, 0 deletions

diff --git a/lib/Parse/ParseExprCXX.cpp b/lib/Parse/ParseExprCXX.cpp
index 681c6adb2e..87aa5dc671 100644
--- a/lib/Parse/ParseExprCXX.cpp
+++ b/lib/Parse/ParseExprCXX.cpp
@@ -377,6 +377,17 @@ Parser::OwningExprResult Parser::ParseCXXTypeid() {
     Result = Actions.ActOnCXXTypeid(OpLoc, LParenLoc, /*isType=*/true,
                                     Ty.get(), RParenLoc);
   } else {
+    // C++0x [expr.typeid]p3:
+    //   When typeid is applied to an expression other than an lvalue of a 
+    //   polymorphic class type [...] The expression is an unevaluated 
+    //   operand (Clause 5).
+    //
+    // Note that we can't tell whether the expression is an lvalue of a 
+    // polymorphic class type until after we've parsed the expression, so
+    // we treat the expression as an unevaluated operand and let semantic
+    // analysis cope with case where the expression is not an unevaluated
+    // operand.
+    EnterUnevaluatedOperand Unevaluated(Actions);
     Result = ParseExpression();
 
     // Match the ')'.