1 /* 2 * Copyright (C) 2019 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include <signal.h> 18 19 #include "profile-extras.h" 20 21 extern "C" { 22 23 void __gcov_dump(void); 24 void __gcov_reset(void); 25 26 // storing SIG_ERR helps us detect (unlikely) looping. 27 static sighandler_t chained_gcov_signal_handler = SIG_ERR; 28 gcov_signal_handler(int signum)29static void gcov_signal_handler(int signum) { 30 __gcov_dump(); 31 __gcov_reset(); 32 if (chained_gcov_signal_handler != SIG_ERR && 33 chained_gcov_signal_handler != SIG_IGN && 34 chained_gcov_signal_handler != SIG_DFL) { 35 (chained_gcov_signal_handler)(signum); 36 } 37 } 38 39 __attribute__((weak)) int init_profile_extras_once = 0; 40 41 // Initialize libprofile-extras: 42 // - Install a signal handler that triggers __gcov_flush on <COVERAGE_FLUSH_SIGNAL>. 43 // 44 // We want this initiazlier to run during load time. 45 // 46 // Just marking init_profile_extras() with __attribute__((constructor)) isn't 47 // enough since the linker drops it from its output since no other symbol from 48 // this static library is referenced. 49 // 50 // We force the linker to include init_profile_extras() by passing 51 // '-uinit_profile_extras' to the linker (in build/soong). init_profile_extras(void)52__attribute__((constructor)) int init_profile_extras(void) { 53 if (init_profile_extras_once) 54 return 0; 55 init_profile_extras_once = 1; 56 57 // is this instance already registered? 58 if (chained_gcov_signal_handler != SIG_ERR) { 59 return -1; 60 } 61 sighandler_t ret1 = signal(COVERAGE_FLUSH_SIGNAL, gcov_signal_handler); 62 if (ret1 == SIG_ERR) { 63 return -1; 64 } 65 chained_gcov_signal_handler = ret1; 66 67 return 0; 68 } 69 } 70