1 files changed, 84 insertions, 0 deletions
diff --git a/compilerplugins/clang/test/passstuffbyref.cxx b/compilerplugins/clang/test/passstuffbyref.cxx
new file mode 100644
index 000000000..d90d6f05b
--- /dev/null
+++ b/compilerplugins/clang/test/passstuffbyref.cxx
@@ -0,0 +1,84 @@
+/* -*- 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/.
+ */
+
+#include <rtl/ustring.hxx>
+#include <o3tl/cow_wrapper.hxx>
+#include <vector>
+
+#pragma clang diagnostic ignored "-Wunknown-warning-option" // for Clang < 13
+#pragma clang diagnostic ignored "-Wunused-but-set-variable"
+
+struct S1 {
+    OUString mv1;
+    OUString const & get() const { return mv1; }
+    OUString const & get2(bool) const { return mv1; }
+};
+struct S2 {
+    OUString mv1;
+    OUString mv2;
+    OUString mv3[2];
+    S1 child;
+    static OUString gs1;
+    o3tl::cow_wrapper<S1> mxCow;
+
+    // make sure we ignore cases where the passed in parameter is std::move'd
+    S2(OUString v1, OUString v2)
+      : mv1(std::move(v1)), mv2((std::move(v2))) {}
+
+    OUString get1() { return mv1; } // expected-error {{rather return class rtl::OUString by const& than by value, to avoid unnecessary copying [loplugin:passstuffbyref]}}
+    OUString get2(bool b) { return b ? mv1 : mv2; } // expected-error {{rather return class rtl::OUString by const& than by value, to avoid unnecessary copying [loplugin:passstuffbyref]}}
+    OUString get3() { return child.mv1; } // expected-error {{rather return class rtl::OUString by const& than by value, to avoid unnecessary copying [loplugin:passstuffbyref]}}
+    OUString get4() { return mv3[0]; } // expected-error {{rather return class rtl::OUString by const& than by value, to avoid unnecessary copying [loplugin:passstuffbyref]}}
+    OUString get5() { return gs1; } // expected-error {{rather return class rtl::OUString by const& than by value, to avoid unnecessary copying [loplugin:passstuffbyref]}}
+    OUString const & get6() { return gs1; }
+    OUString get7() { return get6(); } // expected-error {{rather return class rtl::OUString by const& than by value, to avoid unnecessary copying [loplugin:passstuffbyref]}}
+    OUString & get8() { return gs1; }
+    OUString get9() { return get8(); } // expected-error {{rather return class rtl::OUString by const& than by value, to avoid unnecessary copying [loplugin:passstuffbyref]}}
+    // TODO
+    OUString get10() { return OUString(*&get6()); } // todoexpected-error {{rather return class rtl::OUString by const& than by value, to avoid unnecessary copying [loplugin:passstuffbyref]}}
+    OUString get11() const { return mxCow->get(); } // expected-error {{rather return class rtl::OUString by const& than by value, to avoid unnecessary copying [loplugin:passstuffbyref]}}
+    OUString get12() { return child.get2(false); } // expected-error {{rather return class rtl::OUString by const& than by value, to avoid unnecessary copying [loplugin:passstuffbyref]}}
+
+    // no warning expected
+    OUString set1() { return OUString("xxx"); }
+    OUString set2() { OUString v1("xxx"); return v1; }
+    OUString set3() { S1 v1; return v1.get(); }
+    OUString set4() { OUString v1[1]; return v1[0]; }
+    OUString set5(OUString const & s) { return s; }
+    OUString set6() { std::vector<OUString> v1(1); return v1[0]; }
+    OUString set7(S1 const & s) { return s.get(); }
+    OUString set8() { OUString * p = nullptr; return *p; }
+};
+
+
+// no warning expected
+
+// Don't flag stuff where the local var is hidden behind a self-returning operation like -=:
+S2 &operator -= ( S2 &t1, const S2 &t2 );
+S2 operator-( const S2 &t1, const S2 &t2 )
+{
+    S2 t0 = t1;
+    return t0 -= t2;
+}
+
+void f()
+{
+    S2* s;
+    OUString v1, v2;
+    s = new S2(v1, v2);
+}
+
+struct S3 { S3(int); };
+
+S3 f2() {
+    static int n;
+    return n;
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */