[cfe-commits] r166468 - in /cfe/trunk: lib/AST/Expr.cpp test/SemaCXX/unused.cpp

[Matt Beaumont-Gay]

Author: matthewbg
Date: Tue Oct 23 01:15:26 2012
New Revision: 166468

URL: http://llvm.org/viewvc/llvm-project?rev=166468&view=rev
Log:
Fix -Wunused-value to not warn on expressions that have unresolved lookups due
to dependent arguments.

Modified:
    cfe/trunk/lib/AST/Expr.cpp
    cfe/trunk/test/SemaCXX/unused.cpp

Modified: cfe/trunk/lib/AST/Expr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/Expr.cpp?rev=166468&r1=166467&r2=166468&view=diff
==============================================================================
--- cfe/trunk/lib/AST/Expr.cpp (original)
+++ cfe/trunk/lib/AST/Expr.cpp Tue Oct 23 01:15:26 2012
@@ -1950,6 +1950,11 @@
     return false;
   }
 
+  // If we don't know precisely what we're looking at, let's not warn.
+  case UnresolvedLookupExprClass:
+  case CXXUnresolvedConstructExprClass:
+    return false;
+
   case CXXTemporaryObjectExprClass:
   case CXXConstructExprClass:
     return false;

Modified: cfe/trunk/test/SemaCXX/unused.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/unused.cpp?rev=166468&r1=166467&r2=166468&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/unused.cpp (original)
+++ cfe/trunk/test/SemaCXX/unused.cpp Tue Oct 23 01:15:26 2012
@@ -46,3 +46,18 @@
     int(1); // expected-warning {{expression result unused}}
   }
 }
+
+// Test that constructing an object (which may have side effects) with
+// constructor arguments which are dependent doesn't produce an unused value
+// warning.
+namespace UnresolvedLookup {
+  struct Foo {
+    Foo(int i, int j);
+  };
+  template <typename T>
+  struct Bar {
+    void f(T t) {
+      Foo(t, 0);  // no warning
+    }
+  };
+}