compilerplugins/clang/test/passstuffbyref.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  */
   9
  10 #include <rtl/ustring.hxx>
  11 #include <o3tl/cow_wrapper.hxx>
  12 #include <vector>
  13
  14 struct S1 {
  15     OUString mv1;
  16     OUString const & get() const { return mv1; }
  17     OUString const & get2(bool) const { return mv1; }
  18 };
  19 struct S2 {
  20     OUString mv1;
  21     OUString mv2;
  22     OUString mv3[2];
  23     S1 child;
  24     static OUString gs1;
  25     o3tl::cow_wrapper<S1> mxCow;
  26
  27     // make sure we ignore cases where the passed in parameter is std::move'd
  28     S2(OUString v1, OUString v2)
  29       : mv1(std::move(v1)), mv2((std::move(v2))) {}
  30
  31     OUString get1() { return mv1; } // expected-error {{rather return class rtl::OUString by const& than by value, to avoid unnecessary copying [loplugin:passstuffbyref]}}
  32     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]}}
  33     OUString get3() { return child.mv1; } // expected-error {{rather return class rtl::OUString by const& than by value, to avoid unnecessary copying [loplugin:passstuffbyref]}}
  34     OUString get4() { return mv3[0]; } // expected-error {{rather return class rtl::OUString by const& than by value, to avoid unnecessary copying [loplugin:passstuffbyref]}}
  35     OUString get5() { return gs1; } // expected-error {{rather return class rtl::OUString by const& than by value, to avoid unnecessary copying [loplugin:passstuffbyref]}}
  36     OUString const & get6() { return gs1; }
  37     OUString get7() { return get6(); } // expected-error {{rather return class rtl::OUString by const& than by value, to avoid unnecessary copying [loplugin:passstuffbyref]}}
  38     OUString & get8() { return gs1; }
  39     OUString get9() { return get8(); } // expected-error {{rather return class rtl::OUString by const& than by value, to avoid unnecessary copying [loplugin:passstuffbyref]}}
  40     // TODO
  41     OUString get10() { return OUString(*&get6()); } // todoexpected-error {{rather return class rtl::OUString by const& than by value, to avoid unnecessary copying [loplugin:passstuffbyref]}}
  42     OUString get11() const { return mxCow->get(); } // expected-error {{rather return class rtl::OUString by const& than by value, to avoid unnecessary copying [loplugin:passstuffbyref]}}
  43     OUString get12() { return child.get2(false); } // expected-error {{rather return class rtl::OUString by const& than by value, to avoid unnecessary copying [loplugin:passstuffbyref]}}
  44
  45     // no warning expected
  46     OUString set1() { return OUString("xxx"); }
  47     OUString set2() { OUString v1("xxx"); return v1; }
  48     OUString set3() { S1 v1; return v1.get(); }
  49     OUString set4() { OUString v1[1]; return v1[0]; }
  50     OUString set5(OUString const & s) { return s; }
  51     OUString set6() { std::vector<OUString> v1(1); return v1[0]; }
  52     OUString set7(S1 const & s) { return s.get(); }
  53     OUString set8() { OUString * p = nullptr; return *p; }
  54 };
  55
  56
  57 // no warning expected
  58
  59 // Don't flag stuff where the local var is hidden behind a self-returning operation like -=:
  60 S2 &operator -= ( S2 &t1, const S2 &t2 );
  61 S2 operator-( const S2 &t1, const S2 &t2 )
  62 {
  63     S2 t0 = t1;
  64     return t0 -= t2;
  65 }
  66
  67 void f()
  68 {
  69     S2* s;
  70     OUString v1, v2;
  71     s = new S2(v1, v2);
  72 }
  73
  74 struct S3 { S3(int); };
  75
  76 S3 f2() {
  77     static int n;
  78     return n;
  79 }
  80
  81 /* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */