Normalize mkdir() error codes

libc/calls/internal.h

@@ -243,6 +243,7 @@ int kill$nt(int, int) hidden;
 int link$nt(const char *, const char *) hidden;
 int lstat$nt(const char *, struct stat *) hidden;
 int madvise$nt(void *, size_t, int) hidden;
+int mkdir$nt(const char *, uint32_t) hidden;
 int msync$nt(void *, size_t, int) hidden;
 int nanosleep$nt(const struct timespec *, struct timespec *) hidden;
 int pipe$nt(int[hasatleast 2], unsigned) hidden;

libc/calls/mkdir-nt.c

@@ -0,0 +1,49 @@
+/*-*- 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/internal.h"
+#include "libc/errno.h"
+#include "libc/nt/enum/fileflagandattributes.h"
+#include "libc/nt/files.h"
+#include "libc/nt/runtime.h"
+#include "libc/str/str.h"
+
+static textwindows bool SubpathExistsThatsNotDirectory(char16_t *path) {
+  char16_t *p;
+  uint32_t attrs;
+  while ((p = strrchr16(path, '\\'))) {
+    *p = u'\0';
+    if ((attrs = GetFileAttributes(path)) != -1u) {
+      if (attrs & kNtFileAttributeDirectory) return false;
+      return true;
+    }
+  }
+  return false;
+}
+
+textwindows int mkdir$nt(const char *path, uint32_t mode) {
+  int e;
+  char16_t *p, path16[PATH_MAX];
+  if (__mkntpath(path, path16) == -1) return -1;
+  if (CreateDirectory(path16, NULL)) return 0;
+  e = GetLastError();
+  /* WIN32 doesn't distinguish between ENOTDIR and ENOENT */
+  if (e == ENOTDIR && !SubpathExistsThatsNotDirectory(path16)) e = ENOENT;
+  errno = e;
+  return -1;
+}

libc/calls/mkdir.c

@@ -24,26 +24,23 @@
 #include "libc/sysv/consts/at.h"
 #include "libc/sysv/errfuns.h"
 
-static textwindows noinline int mkdir$nt(const char *path, uint32_t mode) {
-  uint16_t path16[PATH_MAX];
-  if (__mkntpath(path, path16) == -1) return -1;
-  if (CreateDirectory(path16, NULL)) {
-    return 0;
-  } else {
-    return __winerr();
-  }
-}
-
 /**
  * Creates directory a.k.a. folder.
  *
+ *     mkdir o               →  0
+ *     mkdir o/yo/yo/yo      → -1 w/ ENOENT
+ *     if o/yo is file       → -1 w/ ENOTDIR
+ *     if o/yo/yo/yo is dir  → -1 w/ EEXIST
+ *     if o/yo/yo/yo is file → -1 w/ EEXIST
+ *
  * @param path is a UTF-8 string, preferably relative w/ forward slashes
  * @param mode can be, for example, 0755
  * @return 0 on success or -1 w/ errno
  * @error EEXIST, ENOTDIR, ENAMETOOLONG, EACCES
  * @asyncsignalsafe
+ * @see makedirs()
  */
-int mkdir(const char *path, uint32_t mode) {
+int mkdir(const char *path, unsigned mode) {
   if (!path) return efault();
   if (!IsWindows()) {
     return mkdirat$sysv(AT_FDCWD, path, mode);

libc/calls/mkdirat.c

@@ -19,11 +19,26 @@
 #include "libc/calls/calls.h"
 #include "libc/calls/internal.h"
 #include "libc/sysv/consts/at.h"
+#include "libc/sysv/errfuns.h"
 
-int mkdirat(int dirfd, const char *pathname, unsigned mode) {
-  if (dirfd == AT_FDCWD) {
-    return mkdir(pathname, mode);
+/**
+ * Creates directory a.k.a. folder.
+ *
+ * @param dirfd is normally AT_FDCWD
+ * @param path is a UTF-8 string, preferably relative w/ forward slashes
+ * @param mode can be, for example, 0755
+ * @return 0 on success or -1 w/ errno
+ * @error EEXIST, ENOTDIR, ENAMETOOLONG, EACCES, ENOENT
+ * @asyncsignalsafe
+ * @see makedirs()
+ */
+int mkdirat(int dirfd, const char *path, unsigned mode) {
+  if (!path) return efault();
+  if (!IsWindows()) {
+    return mkdirat$sysv(dirfd, path, mode);
+  } else if (dirfd == AT_FDCWD) {
+    return mkdir$nt(path, mode);
   } else {
-    return mkdirat$sysv(dirfd, pathname, mode);
+    return einval();
   }
 }