// weak_undef_file1.cc -- test handling of weak undefined symbols for gold // Copyright (C) 2008-2018 Free Software Foundation, Inc. // Written by Cary Coutant . // This file is part of gold. // This program is free software; you can redistribute it and/or modify // it under the terms of the GNU General Public License as published by // the Free Software Foundation; either version 3 of the License, or // (at your option) any later version. // This program is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // You should have received a copy of the GNU General Public License // along with this program; if not, write to the Free Software // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, // MA 02110-1301, USA. // We test that we correctly deal with weak undefined symbols. // We need to make sure that the symbol is resolved to zero // by the linker and that no dynamic relocation is generated. // This source is used to build a shared library that defines // an arbitrary symbol other than the weak undefined symbol // referenced by the main program. The main program will be // linked with this library so that the symbol remains undefined. // Through the use of the embedded RPATH, the program will load // an alternate shared library that does define the symbol, // so that we can detect whether the symbol was left for runtime // resolution. #include #include "weak_undef.h" int is_such_symbol_ = 1; // We also define a symbol that is not defined by the alternate // library. The main program contains a weak reference to this // symbol, and tests that the reference remains weak even after // the definition was found at link time. int link_time_only = 1; extern int v2 __attribute__ ((weak)); int *v3 = &v2; int t1() { return is_such_symbol_; } // Test that a weak reference from a shared library to a symbol // defined in the main program does get resolved. int t2() { return (&v2 == NULL) ? -1 : v2; } // Test that a weak reference from a shared library to a symbol // defined in the main program does get resolved. int t3() { return (v3 == NULL) ? -1 : *v3; }