blob: 2d31c5d03a9217306352a0993b2e227ca8ee91e1 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
|
#include <unistd.h>
#include <stdlib.h>
#include <sysexits.h>
#include <wasi/api.h>
#include <wasi/libc.h>
#include <wasi/libc-environ.h>
/// If the program doesn't use `environ`, it'll get this version of
/// `__wasilibc_environ`, which isn't initialized with a constructor function.
/// `getenv` etc. call `__wasilibc_ensure_environ()` before accessing it.
/// Statically-initialize it to an invalid pointer value so that we can
/// detect if it's been explicitly initialized (we can't use `NULL` because
/// `clearenv` sets it to NULL.
weak char **__wasilibc_environ = (char **)-1;
// See the comments in libc-environ.h.
void __wasilibc_ensure_environ(void) {
if (__wasilibc_environ == (char **)-1) {
__wasilibc_initialize_environ();
}
}
/// Avoid dynamic allocation for the case where there are no environment
/// variables, but we still need a non-NULL pointer to an (empty) array.
static char *empty_environ[1] = { NULL };
// See the comments in libc-environ.h.
void __wasilibc_initialize_environ(void) {
// Get the sizes of the arrays we'll have to create to copy in the environment.
size_t environ_count;
size_t environ_buf_size;
__wasi_errno_t err = __wasi_environ_sizes_get(&environ_count, &environ_buf_size);
if (err != __WASI_ERRNO_SUCCESS) {
goto oserr;
}
if (environ_count == 0) {
__wasilibc_environ = empty_environ;
return;
}
// Add 1 for the NULL pointer to mark the end, and check for overflow.
size_t num_ptrs = environ_count + 1;
if (num_ptrs == 0) {
goto software;
}
// Allocate memory for storing the environment chars.
char *environ_buf = malloc(environ_buf_size);
if (environ_buf == NULL) {
goto software;
}
// Allocate memory for the array of pointers. This uses `calloc` both to
// handle overflow and to initialize the NULL pointer at the end.
char **environ_ptrs = calloc(num_ptrs, sizeof(char *));
if (environ_ptrs == NULL) {
free(environ_buf);
goto software;
}
// Fill the environment chars, and the `__wasilibc_environ` array with
// pointers into those chars.
// TODO: Remove the casts on `environ_ptrs` and `environ_buf` once the witx is updated with char8 support.
err = __wasi_environ_get((uint8_t **)environ_ptrs, (uint8_t *)environ_buf);
if (err != __WASI_ERRNO_SUCCESS) {
free(environ_buf);
free(environ_ptrs);
goto oserr;
}
__wasilibc_environ = environ_ptrs;
return;
oserr:
_Exit(EX_OSERR);
software:
_Exit(EX_SOFTWARE);
}
// See the comments in libc-environ.h.
void __wasilibc_deinitialize_environ(void) {
if (__wasilibc_environ != (char **)-1) {
// Let libc-top-half clear the old environment-variable strings.
clearenv();
// Set the pointer to the special init value.
__wasilibc_environ = (char **)-1;
}
}
// See the comments in libc-environ.h.
weak void __wasilibc_maybe_reinitialize_environ_eagerly(void) {
// This version does nothing. It may be overridden by a version which does
// something if `environ` is used.
}
|
