71 lines
3.3 KiB
C
71 lines
3.3 KiB
C
|
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
|
||
|
|
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
|
||
|
|
╞══════════════════════════════════════════════════════════════════════════════╡
|
||
|
|
│ Copyright 2020 Justine Alexandra Roberts Tunney │
|
||
|
|
│ │
|
||
|
|
│ This program is free software; you can redistribute it and/or modify │
|
||
|
|
│ it under the terms of the GNU General Public License as published by │
|
||
|
|
│ the Free Software Foundation; version 2 of the License. │
|
||
|
|
│ │
|
||
|
|
│ This program is distributed in the hope that it will be useful, but │
|
||
|
|
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
|
||
|
|
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
|
||
|
|
│ General Public License for more details. │
|
||
|
|
│ │
|
||
|
|
│ You should have received a copy of the GNU General Public License │
|
||
|
|
│ along with this program; if not, write to the Free Software │
|
||
|
|
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
|
||
|
|
│ 02110-1301 USA │
|
||
|
|
╚─────────────────────────────────────────────────────────────────────────────*/
|
||
|
|
#include "libc/dce.h"
|
||
|
|
#include "libc/runtime/runtime.h"
|
||
|
|
#include "libc/str/str.h"
|
||
|
|
#include "libc/sysv/consts/auxv.h"
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Returns auxiliary value, or zero if kernel didn't provide it.
|
||
|
|
*
|
||
|
|
* This function is typically regarded as a libc implementation detail;
|
||
|
|
* thus, the source code is the documentation.
|
||
|
|
*
|
||
|
|
* @see libc/sysv/consts.sh
|
||
|
|
* @see System Five Application Binary Interface § 3.4.3
|
||
|
|
* @asyncsignalsafe
|
||
|
|
*/
|
||
|
|
unsigned long getauxval(unsigned long at) {
|
||
|
|
unsigned long res = 0;
|
||
|
|
if (at != -1) {
|
||
|
|
if (!IsWindows()) {
|
||
|
|
if (!g_auxv) return 0;
|
||
|
|
if (IsXnu()) {
|
||
|
|
if (at) {
|
||
|
|
const char *name =
|
||
|
|
at == AT_EXECFN ? "executable_path" : (const char *)at;
|
||
|
|
const char **auxv = (const char **)g_auxv;
|
||
|
|
unsigned namelen = strlen(name);
|
||
|
|
for (int i = 0; auxv[i]; ++i) {
|
||
|
|
if (strncmp(auxv[i], name, namelen) == 0 &&
|
||
|
|
auxv[i][namelen] == '=') {
|
||
|
|
res = (intptr_t)&auxv[i][namelen + 1];
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
for (const unsigned long *ap = g_auxv; *ap; ap += 2) {
|
||
|
|
if (ap[0] == at) {
|
||
|
|
res = ap[1];
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
/* TODO(jart): GetProcessImageFileName */
|
||
|
|
}
|
||
|
|
if (res == 0 && at == AT_EXECFN) {
|
||
|
|
res = (uintptr_t)program_invocation_name;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return res;
|
||
|
|
}
|