// 1 filename:cpp2011-12-7.cpp // ver 0.1 June.15, 2014 // // 2 original examples and/or notes: // (c) ISO/IEC JTC1 SC22 WG21 N3242, April 12, 2011 // http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2011/n3242.pdf // > 12 Special member functions 12.7 Construction and destruction // // 3 compile and output mechanism: // (c) Dr. OGAWA Kiyoshi, kaizen at gifu-u.ac.jp, // // 4 compile errors and/or warnings: // 4.1(c) Apple LLVM version 5.1 (clang-503.0.40) (based on LLVM 3.4svn) // Target: x86_64-apple-darwin13.2.0, Thread model: posix // Command/Options: c++ -std=c++11 -stdlib=libc++ -Wall cpp2011-12-7.cpp // (c) LLVM 2003-2009 University of Illinois at Urbana-Champaign. // 4.2. g++-4.9 (GCC) 4.9.0 20131229 (experimental) // Copyright (C) 2013 Free Software Foundation, Inc. // This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. // http://gcc.gnu.org/onlinedocs/gcc/Standards.html // Command/Options: g++-4.9 -std=c++11 -Wall cpp2011-12-7.cpp // g++-4.9: error: unrecognized command line option '-stdlib=libc++' // Configuration:brew install gcc49 // // 4.3. Visual Studio Express 2013, // (c) Microsoft http://www.visualstudio.com/ // SPEC: // Windows 7, .NET Framework // (c) VMware, Inc. // VMWare fusion 6 // // 5. Hardware: MacBook Pro, //(c) Intel http://ark.intel.com/products/37006/ //Core 2 Duo 2.53GHz, 8GB, 1067MHz DDR3 // // 6. Special Thanks: Upper organizatios and // ITSCJ/IPSJ http://www.itscj.ipsj.or.jp/itscj_english/index.html // Renesas Electronics Corporation.http://www.renesas.com/ // NPO SESSAME project, http://www.sessame.jp/workinggroup/WorkingGroup3/ // Toyo Corporation, http://www.toyo.co.jp/English/ // Japan Standard Association, http://bit.ly/1lzykg1 // NPO TOPPERS project, https://www.toppers.jp/asp-d-download.html // Daido Universcity, http://www.daido-it.ac.jp/gakubugakka/computer/index.html // WITZ Co.Ltd., http://www.witz-inc.co.jp/products/solution/solution.html // SevenWise.co., http://www.7ws.co.jp/index.html // TOYOTA Motor Corporation, http://toyota.jp/ // IT planning Inc., http://www.itpl.co.jp/en/index.html // DENSO Corporation, http://www.globaldenso.com/en/ // Aisin Seiki co. Ltd., http://www.aisin.com/ // Spancion Inc., http://www.spansion.com/ // Yazaki Corporation, http://www.yazaki-group.com/global/ // Pananosic Corporation, http://www.panasonic.net/ // SWEST: Summer Workshop on Embedded System Technologies , http://swest.toppers.jp // CEST: Consortium for Embedded System Technology, http://www.ertl.jp/CEST/ // JUSE: Union of Japanese Scientists and Engineers, http://www.juse.or.jp/e/ // OSC:Open Source Conference, http://www.ospn.jp/ #include //#include //#include //#include //#include //#include //#include //#include #include //#include //#include //#include using namespace std; struct X { int i; }; struct Y : X { Y(); }; // non-trivial struct A { int a; }; struct B : public A { int j; Y y; }; // non-trivial extern B bobj; B* pb = &bobj; // OK int* p1 = &bobj.a; // undefined, refers to base class member int* p2 = &bobj.y.i; // undefined, refers to member’s member A* pa = &bobj; // undefined, upcast to a base class type B bobj; // definition of bobj extern X xobj; int* p3 = &xobj.i; //OK, X is a trivial class X xobj; // struct W { int j; }; struct X0 : public virtual W { }; struct Y0 { int *p; X0 x; Y0() : p(&x.j) { // undefined, x is not yet constructed } }; // struct A1 { }; struct B1 : virtual A1 { }; struct C1 : B1 { }; struct D1 : virtual A1 { D1(A1*); }; struct X1 { X1(A1*); }; struct E : C1, D1, X1 { E() : D1(this), // undefined: upcast from E* to A* // might use path E* ! D* ! A* // but D is not constructed // D((C*)this), // defined: // E* ! C* defined because E() has started // and C* ! A* defined because // C fully constructed X1(this) { // defined: upon construction of X, // C/B/D/A sublattice is fully constructed } }; // struct V { virtual void f(); virtual void g(); }; struct A2 : virtual V { virtual void f(); }; struct B2 : virtual V { virtual void g(); B2(V*, A2*); }; struct D2 : A2, B2 { virtual void f(); virtual void g(); D2() : B2((A2*)this, this) { } }; B2::B2(V* v, A2* a) { f(); // calls V::f, not A::f g(); // calls B::g, not D::g v->g(); // v is base of B, the call is well-defined, calls B::g a->f(); // undefined behavior, a’s type not a base of B } // struct V3 { virtual void f(); }; struct A3 : virtual V3 { }; struct B3 : virtual V3 { B3(V3*, A3*); }; struct D3 : A3, B3 { D3() : B3((A3*)this, this) { } }; B3::B3(V3* v, A3* a) { typeid(*this); // type_info for B typeid(*v); // well-defined: *v has type V, a base of B // yields type_info for B typeid(*a); // undefined behavior: type A not a base of B dynamic_cast(v); // well-defined: v of type V*, V base of B // results in B* dynamic_cast(a); // undefined behavior, // a has type A*, A not a base of B } int main() { // cout << "12 Special member functions 12.7 Construction and destruction" << std::endl; return 0; } // 1 error // 1.1 gcc: g++-4.9 -std=c++11 -Wall cpp2011-12-7.cpp cpp2011-12-7.cpp: In constructor 'B3::B3(V3*, A3*)': cpp2011-12-7.cpp:149:9: error: must #include before using typeid typeid(*this); // type_info for B ^ cpp2011-12-7.cpp:150:9: error: must #include before using typeid typeid(*v); // well-defined: *v has type V, a base of B ^ cpp2011-12-7.cpp:152:9: error: must #include before using typeid typeid(*a); // undefined behavior: type A not a base of B ^ // 2 link error // 2.1 llvm: c++ -std=c++11 -stdlib=libc++ -Wall cpp2011-12-7.cpp cpp2011-12-7.cpp:149:1: warning: expression result unused [-Wunused-value] typeid(*this); // type_info for B ^~~~~~~~~~~~~ cpp2011-12-7.cpp:150:1: warning: expression result unused [-Wunused-value] typeid(*v); // well-defined: *v has type V, a base of B ^~~~~~~~~~ cpp2011-12-7.cpp:152:1: warning: expression result unused [-Wunused-value] typeid(*a); // undefined behavior: type A not a base of B ^~~~~~~~~~ cpp2011-12-7.cpp:153:1: warning: expression result unused [-Wunused-value] dynamic_cast(v); // well-defined: v of type V*, V base of B ^~~~~~~~~~~~~~~~~~~~ cpp2011-12-7.cpp:155:1: warning: expression result unused [-Wunused-value] dynamic_cast(a); // undefined behavior, ^~~~~~~~~~~~~~~~~~~~ 5 warnings generated. Undefined symbols for architecture x86_64: "Y::Y()", referenced from: B::B() in cpp2011-12-7-887c07.o "V3::f()", referenced from: vtable for B3 in cpp2011-12-7-887c07.o "typeinfo for V3", referenced from: B3::B3(V3*, A3*) in cpp2011-12-7-887c07.o B3::B3(V3*, A3*) in cpp2011-12-7-887c07.o typeinfo for B3 in cpp2011-12-7-887c07.o typeinfo for A3 in cpp2011-12-7-887c07.o "vtable for V", referenced from: V::V() in cpp2011-12-7-887c07.o NOTE: a missing vtable usually means the first non-inline virtual member function has no definition. "vtable for B2", referenced from: B2::B2(V*, A2*) in cpp2011-12-7-887c07.o NOTE: a missing vtable usually means the first non-inline virtual member function has no definition. "vtable for V3", referenced from: V3::V3() in cpp2011-12-7-887c07.o NOTE: a missing vtable usually means the first non-inline virtual member function has no definition. ld: symbol(s) not found for architecture x86_64 clang: error: linker command failed with exit code 1 (use -v to see invocation)