/* * Copyright (C) 2014 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include <stdio.h> #include <stdlib.h> static int g_flag = 0; static void __attribute__((constructor)) init_flag() { g_flag = 1; } static const char* is_ctor_called() __attribute__ ((ifunc("is_ctor_called_ifun"))); const char* foo() __attribute__ ((ifunc ("foo_ifunc"))); // Static linker creates GLOBAL/IFUNC symbol and JUMP_SLOT relocation type for plt segment const char* is_ctor_called_jump_slot() __attribute__ ((ifunc("is_ctor_called_ifun"))); const char* is_ctor_called_irelative() { // Call internal ifunc-resolved function with IRELATIVE reloc return is_ctor_called(); } const char* return_true() { return "true"; } const char* return_false() { return "false"; } const char* f1() { return "unset"; } const char* f2() { return "set"; } void* is_ctor_called_ifun() { return g_flag == 0 ? return_false : return_true; } void* foo_ifunc() { char* choice = getenv("IFUNC_CHOICE"); return choice == NULL ? f1 : f2; } const char* foo_library() { return foo(); }