[Libreoffice-commits] core.git: compilerplugins/clang solenv/CompilerTest_compilerplugins_clang.mk

[Stephan Bergmann]

 compilerplugins/clang/faileddyncast.cxx      |    6 ++++++
 compilerplugins/clang/test/faileddyncast.cxx |   21 +++++++++++++++++++++
 solenv/CompilerTest_compilerplugins_clang.mk |    1 +
 3 files changed, 28 insertions(+)

New commits:
commit 1c680d763e770250b8e1b0e63e62a4f5ecda3b74
Author: Stephan Bergmann <sbergman at redhat.com>
Date:   Fri Oct 20 14:48:16 2017 +0200

    Avoid loplugin:faileddyncast for "unnecessary", up-casting dynamic_cast
    
    Change-Id: Iecb943db0aff7ffc21cc2f6adb625be369255b32
    Reviewed-on: https://gerrit.libreoffice.org/43606
    Tested-by: Jenkins <ci at libreoffice.org>
    Reviewed-by: Noel Grandin <noel.grandin at collabora.co.uk>

diff --git a/compilerplugins/clang/faileddyncast.cxx b/compilerplugins/clang/faileddyncast.cxx
index bdc9ce6e5fad..9a257d7d8a23 100644
--- a/compilerplugins/clang/faileddyncast.cxx
+++ b/compilerplugins/clang/faileddyncast.cxx
@@ -80,7 +80,13 @@ bool isAlwaysNull(CXXDynamicCastExpr const * expr) {
     return false;
 #endif
 
+#if 0
   return !DestRD->isDerivedFrom(SrcRD);
+#else
+  return !(DestRD->isDerivedFrom(SrcRD)
+           || SrcRD->isDerivedFrom(DestRD)
+           || SrcRD == DestRD);
+#endif
 }
 
 class FailedDynCast:
diff --git a/compilerplugins/clang/test/faileddyncast.cxx b/compilerplugins/clang/test/faileddyncast.cxx
new file mode 100644
index 000000000000..7d835e041f7a
--- /dev/null
+++ b/compilerplugins/clang/test/faileddyncast.cxx
@@ -0,0 +1,21 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+struct S1 { virtual ~S1(); };
+struct S2 final: S1 {};
+struct S3: S1 {};
+
+void f(S1 * s1, S2 * s2) {
+    (void) dynamic_cast<S2 *>(s1);
+    (void) dynamic_cast<S1 *>(s2);
+    (void) dynamic_cast<S2 *>(s2);
+    (void) dynamic_cast<S3 *>(s2); // expected-error {{dynamic_cast from 'S2 *' to 'S3 *' always fails [loplugin:faileddyncast]}}
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */
diff --git a/solenv/CompilerTest_compilerplugins_clang.mk b/solenv/CompilerTest_compilerplugins_clang.mk
index 26306dccc983..97a870d9c296 100644
--- a/solenv/CompilerTest_compilerplugins_clang.mk
+++ b/solenv/CompilerTest_compilerplugins_clang.mk
@@ -21,6 +21,7 @@ $(eval $(call gb_CompilerTest_add_exception_objects,compilerplugins_clang, \
     compilerplugins/clang/test/droplong \
     compilerplugins/clang/test/externvar \
     compilerplugins/clang/test/expressionalwayszero \
+    compilerplugins/clang/test/faileddyncast \
     compilerplugins/clang/test/finalprotected \
     compilerplugins/clang/test/flatten \
     compilerplugins/clang/test/loopvartoosmall \