os_nodetype: impl with libuv

src/nvim/fileio.c

@@ -2576,7 +2576,7 @@ buf_write (
         errmsg = (char_u *)_("is a directory");
         goto fail;
       }
-      if (mch_nodetype(fname) != NODE_WRITABLE) {
+      if (os_nodetype((char *)fname) != NODE_WRITABLE) {
         errnum = (char_u *)"E503: ";
         errmsg = (char_u *)_("is not a file or writable device");
         goto fail;
@@ -2588,11 +2588,11 @@ buf_write (
       perm = -1;
     }
   }
-#else /* !UNIX */
+#else /* win32 */
       /*
        * Check for a writable device name.
        */
-  c = mch_nodetype(fname);
+  c = os_nodetype((char *)fname);
   if (c == NODE_OTHER) {
     errnum = (char_u *)"E503: ";
     errmsg = (char_u *)_("is not a file or writable device");

src/nvim/os/fs.c

@@ -94,9 +94,74 @@ bool os_isdir(const char_u *name)
   return true;
 }
 
+/// Check what `name` is:
+/// @return NODE_NORMAL: file or directory (or doesn't exist)
+///         NODE_WRITABLE: writable device, socket, fifo, etc.
+///         NODE_OTHER: non-writable things
+int os_nodetype(const char *name)
+{
+#ifdef WIN32
+  // Edge case from Vim os_win32.c:
+  // We can't open a file with a name "\\.\con" or "\\.\prn", trying to read
+  // from it later will cause Vim to hang. Thus return NODE_WRITABLE here.
+  if (STRNCMP(name, "\\\\.\\", 4) == 0) {
+    return NODE_WRITABLE;
+  }
+#endif
+
+  uv_stat_t statbuf;
+  if (os_stat(name, &statbuf) == 0) {
+    return NODE_NORMAL;
+  }
+
+#ifndef WIN32
+  // libuv does not handle BLK and DIR in uv_handle_type.
+  //    Related: https://github.com/joyent/libuv/pull/1421
+  if (S_ISREG(statbuf.st_mode) || S_ISDIR(statbuf.st_mode)) {
+    return NODE_NORMAL;
+  }
+  if (S_ISBLK(statbuf.st_mode)) {  // block device isn't writable
+    return NODE_OTHER;
+  }
+#endif
+
+  // Vim os_win32.c:mch_nodetype does this (since patch 7.4.015):
+  //    if (enc_codepage >= 0 && (int)GetACP() != enc_codepage) {
+  //      wn = enc_to_utf16(name, NULL);
+  //      hFile = CreatFile(wn, ...)
+  // to get a HANDLE. But libuv just calls win32's _get_osfhandle() on the fd we
+  // give it. uv_fs_open calls fs__capture_path which does a similar dance and
+  // saves us the hassle.
+
+  int nodetype = NODE_WRITABLE;
+  int fd = os_open(name, O_RDONLY, 0);
+  switch(uv_guess_handle(fd)) {
+    case UV_TTY:         // FILE_TYPE_CHAR
+      nodetype = NODE_WRITABLE;
+      break;
+    case UV_FILE:        // FILE_TYPE_DISK
+      nodetype = NODE_NORMAL;
+      break;
+    case UV_NAMED_PIPE:  // not handled explicitly in Vim os_win32.c
+    case UV_UDP:         // unix only
+    case UV_TCP:         // unix only
+    case UV_UNKNOWN_HANDLE:
+    default:
+#ifdef WIN32
+      nodetype = NODE_OTHER;
+#else
+      nodetype = NODE_WRITABLE;  // Everything else is writable?
+#endif
+      break;
+  }
+
+  close(fd);
+  return nodetype;
+}
+
 /// Checks if the given path represents an executable file.
 ///
-/// @param[in]  name     The name of the executable.
+/// @param[in]  name     Name of the executable.
 /// @param[out] abspath  Path of the executable, if found and not `NULL`.
 ///
 /// @return `true` if `name` is executable and

src/nvim/os/fs_defs.h

@@ -26,4 +26,10 @@ typedef struct {
 /// negative libuv error codes are returned by a number of os functions.
 #define os_strerror uv_strerror
 
+// Values returned by os_nodetype()
+#define NODE_NORMAL     0  // file or directory, check with os_isdir()
+#define NODE_WRITABLE   1  // something we can write to (character
+                           // device, fifo, socket, ..)
+#define NODE_OTHER      2  // non-writable thing (e.g., block device)
+
 #endif  // NVIM_OS_FS_DEFS_H

src/nvim/os_unix.c

@@ -136,26 +136,6 @@ void mch_free_acl(vim_acl_T aclent)
 }
 #endif
 
-/*
- * Check what "name" is:
- * NODE_NORMAL: file or directory (or doesn't exist)
- * NODE_WRITABLE: writable device, socket, fifo, etc.
- * NODE_OTHER: non-writable things
- */
-int mch_nodetype(char_u *name)
-{
-  struct stat st;
-
-  if (stat((char *)name, &st))
-    return NODE_NORMAL;
-  if (S_ISREG(st.st_mode) || S_ISDIR(st.st_mode))
-    return NODE_NORMAL;
-  if (S_ISBLK(st.st_mode))      /* block device isn't writable */
-    return NODE_OTHER;
-  /* Everything else is writable? */
-  return NODE_WRITABLE;
-}
-
 void mch_exit(int r)
 {
   exiting = true;

src/nvim/os_unix.h

@@ -4,12 +4,6 @@
 #include "nvim/types.h"  // for vim_acl_T
 #include "nvim/os/shell.h"
 
-/* Values returned by mch_nodetype() */
-#define NODE_NORMAL     0       /* file or directory, check with os_isdir()*/
-#define NODE_WRITABLE   1       /* something we can write to (character
-                                   device, fifo, socket, ..) */
-#define NODE_OTHER      2       /* non-writable thing (e.g., block device) */
-
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "os_unix.h.generated.h"
 #endif