1 /*
2  * Copyright (C) 2015 The Android Open Source Project
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *  * Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  *  * Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in
12  *    the documentation and/or other materials provided with the
13  *    distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #pragma once
30 
31 #include <sys/cdefs.h>
32 
33 #if __ANDROID_API__ < 21
34 
35 #include <errno.h>
36 #include <signal.h>
37 #include <string.h>
38 
39 __BEGIN_DECLS
40 
41 sighandler_t bsd_signal(int __signal, sighandler_t __handler) __REMOVED_IN(21);
42 
43 /* These weren't introduced until L. */
44 int __libc_current_sigrtmax() __attribute__((__weak__)) __VERSIONER_NO_GUARD;
45 int __libc_current_sigrtmin() __attribute__((__weak__)) __VERSIONER_NO_GUARD;
46 
__ndk_legacy___libc_current_sigrtmax()47 static __inline int __ndk_legacy___libc_current_sigrtmax() {
48   /*
49    * The NDK doesn't use libclang_rt.builtins yet (https://github.com/android/ndk/issues/1231) so it
50    * can't use __builtin_available, but the platform builds with -Werror=unguarded-availability so
51    * it requires __builtin_available.
52    */
53 #if defined(__ANDROID_UNAVAILABLE_SYMBOLS_ARE_WEAK__)
54   if (__builtin_available(android 21, *)) {
55 #else
56   if (__libc_current_sigrtmax) {
57 #endif
58     return __libc_current_sigrtmax();
59   }
60   return __SIGRTMAX; /* Should match __libc_current_sigrtmax. */
61 }
62 
63 static __inline int __ndk_legacy___libc_current_sigrtmin() {
64   /*
65    * The NDK doesn't use libclang_rt.builtins yet (https://github.com/android/ndk/issues/1231) so it
66    * can't use __builtin_available, but the platform builds with -Werror=unguarded-availability so
67    * it requires __builtin_available.
68    */
69 #if defined(__ANDROID_UNAVAILABLE_SYMBOLS_ARE_WEAK__)
70   if (__builtin_available(android 21, *)) {
71 #else
72   if (__libc_current_sigrtmin) {
73 #endif
74     return __libc_current_sigrtmin();
75   }
76   return __SIGRTMIN + 7; /* Should match __libc_current_sigrtmin. */
77 }
78 
79 #undef SIGRTMAX
80 #define SIGRTMAX __ndk_legacy___libc_current_sigrtmax()
81 #undef SIGRTMIN
82 #define SIGRTMIN __ndk_legacy___libc_current_sigrtmin()
83 
84 static __inline int sigismember(const sigset_t *set, int signum) {
85   /* Signal numbers start at 1, but bit positions start at 0. */
86   int bit = signum - 1;
87   const unsigned long *local_set = (const unsigned long *)set;
88   if (set == NULL || bit < 0 || bit >= (int)(8 * sizeof(sigset_t))) {
89     errno = EINVAL;
90     return -1;
91   }
92   return (int)((local_set[bit / LONG_BIT] >> (bit % LONG_BIT)) & 1);
93 }
94 
95 static __inline int sigaddset(sigset_t *set, int signum) {
96   /* Signal numbers start at 1, but bit positions start at 0. */
97   int bit = signum - 1;
98   unsigned long *local_set = (unsigned long *)set;
99   if (set == NULL || bit < 0 || bit >= (int)(8 * sizeof(sigset_t))) {
100     errno = EINVAL;
101     return -1;
102   }
103   local_set[bit / LONG_BIT] |= 1UL << (bit % LONG_BIT);
104   return 0;
105 }
106 
107 static __inline int sigdelset(sigset_t *set, int signum) {
108   /* Signal numbers start at 1, but bit positions start at 0. */
109   int bit = signum - 1;
110   unsigned long *local_set = (unsigned long *)set;
111   if (set == NULL || bit < 0 || bit >= (int)(8 * sizeof(sigset_t))) {
112     errno = EINVAL;
113     return -1;
114   }
115   local_set[bit / LONG_BIT] &= ~(1UL << (bit % LONG_BIT));
116   return 0;
117 }
118 
119 static __inline int sigemptyset(sigset_t *set) {
120   if (set == NULL) {
121     errno = EINVAL;
122     return -1;
123   }
124   memset(set, 0, sizeof(sigset_t));
125   return 0;
126 }
127 
128 static __inline int sigfillset(sigset_t *set) {
129   if (set == NULL) {
130     errno = EINVAL;
131     return -1;
132   }
133   memset(set, ~0, sizeof(sigset_t));
134   return 0;
135 }
136 
137 static __inline sighandler_t signal(int s, sighandler_t f) {
138   return bsd_signal(s, f);
139 }
140 
141 __END_DECLS
142 
143 #endif
144