Implement getcwd() for XNU

libc/calls/calls.h

@@ -232,10 +232,6 @@ int prctl();
 int sysctl(const int *, unsigned, void *, size_t *, void *, size_t);
 int fchdir(int);
 
-#define getcwd(BUF, SIZE)                                                    \
-  (__builtin_constant_p(BUF) && (&(BUF)[0] == NULL) ? get_current_dir_name() \
-                                                    : getcwd(BUF, SIZE))
-
 /*───────────────────────────────────────────────────────────────────────────│─╗
 │ cosmopolitan § system calls » formatting                                 ─╬─│┼
 ╚────────────────────────────────────────────────────────────────────────────│*/
@@ -248,6 +244,10 @@ int vdprintf(int, const char *, va_list) paramsnonnull();
 ╚────────────────────────────────────────────────────────────────────────────│*/
 #if defined(__GNUC__) && !defined(__STRICT_ANSI__)
 
+#define getcwd(BUF, SIZE)                                       \
+  (__builtin_constant_p(BUF) && !(BUF) ? get_current_dir_name() \
+                                       : getcwd(BUF, SIZE))
+
 void _init_onntconsoleevent(void);
 void _init_wincrash(void);
 

libc/calls/getcwd-nt.c

@@ -23,12 +23,12 @@
 #include "libc/sysv/errfuns.h"
 
 textwindows char *getcwd$nt(char *buf, size_t size) {
-  uint16_t name16[PATH_MAX + 1];
+  uint16_t name16[PATH_MAX];
   if (GetCurrentDirectory(ARRAYLEN(name16), name16)) {
     tprecode16to8(buf, size, name16);
     return buf;
   } else {
     __winerr();
+    return NULL;
   }
-  return NULL;
 }

libc/calls/getcwd-xnu.c

@@ -0,0 +1,57 @@
+/*-*- 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 2021 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/calls/calls.h"
+#include "libc/calls/internal.h"
+#include "libc/calls/struct/stat.h"
+#include "libc/str/str.h"
+#include "libc/sysv/consts/at.h"
+#include "libc/sysv/consts/o.h"
+#include "libc/sysv/errfuns.h"
+
+#define XNU_F_GETPATH  50
+#define XNU_MAXPATHLEN 1024
+
+char *getcwd$xnu(char *res, size_t size) {
+  int fd;
+  struct stat st[2];
+  char buf[XNU_MAXPATHLEN], *ret = NULL;
+  if ((fd = openat$sysv(AT_FDCWD, ".", O_RDONLY | O_DIRECTORY)) != -1) {
+    if (fstat$sysv(fd, &st[0]) != -1) {
+      if (st[0].st_dev && st[0].st_ino) {
+        if (fcntl$sysv(fd, XNU_F_GETPATH, buf) != -1) {
+          if (fstatat$sysv(AT_FDCWD, buf, &st[1], 0) != -1) {
+            if (st[0].st_dev == st[1].st_dev && st[0].st_ino == st[1].st_ino) {
+              if (memccpy(res, buf, '\0', size)) {
+                ret = res;
+              } else {
+                erange();
+              }
+            } else {
+              einval();
+            }
+          }
+        }
+      } else {
+        einval();
+      }
+    }
+    close(fd);
+  }
+  return ret;
+}

libc/calls/getcwd.c

@@ -19,8 +19,6 @@
 #include "libc/calls/calls.h"
 #include "libc/calls/internal.h"
 #include "libc/dce.h"
-#include "libc/errno.h"
-#include "libc/sysv/errfuns.h"
 
 /**
  * Returns current working directory.
@@ -34,28 +32,16 @@
  * @error ERANGE, EINVAL
  */
 char *(getcwd)(char *buf, size_t size) {
-  if (buf) {
-    buf[0] = '\0';
-    if (!IsWindows()) {
-      int olderr = errno;
-      if (getcwd$sysv(buf, size) != NULL) {
-        return buf;
-      } else if (IsXnu() && errno == ENOSYS) {
-        if (size >= 2) {
-          buf[0] = '.'; /* XXX: could put forth more effort */
-          buf[1] = '\0';
-          errno = olderr;
-          return buf;
-        } else {
-          erange();
-        }
-      }
-      return NULL;
+  if (buf && size) buf[0] = '\0';
+  if (!IsWindows()) {
+    if (IsXnu()) {
+      return getcwd$xnu(buf, size);
+    } else if (getcwd$sysv(buf, size) != (void *)-1) {
+      return buf;
     } else {
-      return getcwd$nt(buf, size);
+      return NULL;
     }
   } else {
-    efault();
-    return NULL;
+    return getcwd$nt(buf, size);
   }
 }

libc/calls/hefty/get_current_dir_name.c

@@ -32,7 +32,6 @@
  */
 nodiscard char *get_current_dir_name(void) {
   char *buf, *res;
-  if ((res = getenv("PWD"))) return strdup(res);
   if (!(buf = malloc(PATH_MAX))) return NULL;
   if (!(res = (getcwd)(buf, PATH_MAX))) free(buf);
   return res;

libc/calls/internal.h

@@ -99,6 +99,7 @@ forceinline size_t clampio(size_t size) {
 ╚────────────────────────────────────────────────────────────────────────────│*/
 
 char *getcwd$sysv(char *, u64) hidden;
+char *getcwd$xnu(char *, u64) hidden;
 i32 __dup3$sysv(i32, i32, i32) hidden;
 i32 __execve$sysv(const char *, char *const[], char *const[]) hidden;
 i32 __fstat$sysv(i32, struct stat *) hidden;
@@ -120,7 +121,7 @@ i32 fchmod$sysv(i32, u32) hidden;
 i32 fchmodat$sysv(i32, const char *, u32, u32) hidden;
 i32 fchown$sysv(i64, u32, u32) hidden;
 i32 fchownat$sysv(i32, const char *, u32, u32, u32) hidden;
-i32 fcntl$sysv(i32, i32, i32) hidden;
+i32 fcntl$sysv(i32, i32, ...) hidden;
 i32 fdatasync$sysv(i32) hidden;
 i32 flock$sysv(i32, i32) hidden;
 i32 fork$sysv(void) hidden;
@@ -151,7 +152,7 @@ i32 mprotect$sysv(void *, u64, i32) hidden;
 i32 msync$sysv(void *, u64, i32) hidden;
 i32 munmap$sysv(void *, u64) hidden;
 i32 nanosleep$sysv(const struct timespec *, struct timespec *) hidden;
-i32 openat$sysv(i32, const char *, i32, i32) hidden;
+i32 openat$sysv(i32, const char *, i32, ...) hidden;
 i32 pause$sysv(void) hidden;
 i32 pipe$sysv(i32[hasatleast 2]) hidden;
 i32 pipe2$sysv(i32[hasatleast 2], u32) hidden;