loplugin:redundantcast: const_cast to same type

Change-Id: I1abdc2ab0b145e12f7fb00db529f52c11e4d7cfd

1 files changed, 19 insertions, 0 deletions

diff --git a/compilerplugins/clang/redundantcast.cxx b/compilerplugins/clang/redundantcast.cxx
index 474dafa11e85..976e80e5495d 100644
--- a/compilerplugins/clang/redundantcast.cxx
+++ b/compilerplugins/clang/redundantcast.cxx
@@ -52,6 +52,8 @@ public:
 
     bool VisitCXXReinterpretCastExpr(CXXReinterpretCastExpr const * expr);
 
+    bool VisitCXXConstCastExpr(CXXConstCastExpr const * expr);
+
     bool VisitCallExpr(CallExpr const * expr);
 
     bool VisitCXXDeleteExpr(CXXDeleteExpr const * expr);
@@ -263,6 +265,23 @@ bool RedundantCast::VisitCXXReinterpretCastExpr(
     return true;
 }
 
+bool RedundantCast::VisitCXXConstCastExpr(CXXConstCastExpr const * expr) {
+    if (ignoreLocation(expr)) {
+        return true;
+    }
+    if (expr->getTypeAsWritten().getCanonicalType().getTypePtr()
+        == (expr->getSubExprAsWritten()->getType().getCanonicalType()
+            .getTypePtr()))
+    {
+        report(
+            DiagnosticsEngine::Warning, "redundant const_cast from %0 to %1",
+            expr->getExprLoc())
+            << expr->getSubExprAsWritten()->getType()
+            << expr->getTypeAsWritten() << expr->getSourceRange();
+    }
+    return true;
+}
+
 bool RedundantCast::VisitCallExpr(CallExpr const * expr) {
     if (ignoreLocation(expr)) {
         return true;