r186793 - report unused-value warning also for warn_unused types

[Lubos Lunak]

Author: llunak
Date: Sun Jul 21 08:15:58 2013
New Revision: 186793

URL: http://llvm.org/viewvc/llvm-project?rev=186793&view=rev
Log:
report unused-value warning also for warn_unused types


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

Modified: cfe/trunk/lib/AST/Expr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/Expr.cpp?rev=186793&r1=186792&r2=186793&view=diff
==============================================================================
--- cfe/trunk/lib/AST/Expr.cpp (original)
+++ cfe/trunk/lib/AST/Expr.cpp Sun Jul 21 08:15:58 2013
@@ -2075,8 +2075,17 @@ bool Expr::isUnusedResultAWarning(const
     return false;
 
   case CXXTemporaryObjectExprClass:
-  case CXXConstructExprClass:
+  case CXXConstructExprClass: {
+    if (const CXXRecordDecl *Type = getType()->getAsCXXRecordDecl()) {
+      if (Type->hasAttr<WarnUnusedAttr>()) {
+        WarnE = this;
+        Loc = getLocStart();
+        R1 = getSourceRange();
+        return true;
+      }
+    }
     return false;
+  }
 
   case ObjCMessageExprClass: {
     const ObjCMessageExpr *ME = cast<ObjCMessageExpr>(this);

Modified: cfe/trunk/test/SemaCXX/warn-unused-value.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/warn-unused-value.cpp?rev=186793&r1=186792&r2=186793&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/warn-unused-value.cpp (original)
+++ cfe/trunk/test/SemaCXX/warn-unused-value.cpp Sun Jul 21 08:15:58 2013
@@ -49,3 +49,23 @@ namespace test2 {
   }
 }
 
+namespace test3 {
+struct Used {
+  Used();
+  Used(int);
+  Used(int, int);
+};
+struct __attribute__((warn_unused)) Unused {
+  Unused();
+  Unused(int);
+  Unused(int, int);
+};
+void f() {
+  Used();
+  Used(1);
+  Used(1, 1);
+  Unused();     // expected-warning {{expression result unused}}
+  Unused(1);    // expected-warning {{expression result unused}}
+  Unused(1, 1); // expected-warning {{expression result unused}}
+}
+}