1/*
2 * Copyright (C) 2016 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 <stdint.h>
18#include <stdlib.h>
19#include <crt_priv.h>
20
21static void callVectors(const void *from_addr, const void *to_addr)
22{
23    typedef void (* const callVect)(void);
24    callVect *start = (callVect *)from_addr;
25    callVect *end = (callVect *)to_addr;
26    const int32_t step = from_addr < to_addr ? 1 : -1;
27    const int32_t count = step > 0 ? end - start : start - end;
28
29    // basic sanity check
30    if (&start[step * count] != end)
31        return;
32
33    for (; start != end; start += step) {
34        callVect vec = *start;
35        if (vec != NULL)
36            vec();
37    }
38}
39
40void __crt_init(void)
41{
42    extern uint32_t __init_array_start[];
43    extern uint32_t __init_array_end[];
44
45    callVectors(__init_array_start, __init_array_end);
46}
47
48void __crt_exit(void)
49{
50    extern uint32_t __fini_array_start[];
51    extern uint32_t __fini_array_end[];
52    extern uint32_t __bss_end[];
53    extern uint32_t __got_start[];
54
55    // call global destructors
56    callVectors(__fini_array_start, __fini_array_end);
57    if (&__fini_array_end[1] <= __got_start) {
58        // call registered static destructors
59        callVectors(__bss_end + __fini_array_end[0] * (sizeof(uint32_t)), __bss_end);
60    }
61}
62