Split file_unlink into file and directory forms.

Split file_unlink into file_unlink_file and file_unlink_directory.
Rather than one function with a flags argument to say which of two
things to do, having two functions allows finer-grained import
capabilities.

Also, standardize the errno choices for the unlink functions, in
cases where underlying Unix platforms differ.

Author: sunfishcode

expected/wasm32-wasi/predefined-macros.txt

@@ -3552,9 +3552,10 @@
 #define __WASI_RIGHT_FILE_STAT_SET_SIZE (UINT64_C(0x0000000000080000))
 #define __WASI_RIGHT_FILE_STAT_SET_TIMES (UINT64_C(0x0000000000100000))
 #define __WASI_RIGHT_FILE_SYMLINK (UINT64_C(0x0000000001000000))
-#define __WASI_RIGHT_FILE_UNLINK (UINT64_C(0x0000000002000000))
-#define __WASI_RIGHT_POLL_FD_READWRITE (UINT64_C(0x0000000004000000))
-#define __WASI_RIGHT_SOCK_SHUTDOWN (UINT64_C(0x0000000008000000))
+#define __WASI_RIGHT_FILE_UNLINK_DIRECTORY (UINT64_C(0x0000000004000000))
+#define __WASI_RIGHT_FILE_UNLINK_FILE (UINT64_C(0x0000000002000000))
+#define __WASI_RIGHT_POLL_FD_READWRITE (UINT64_C(0x0000000008000000))
+#define __WASI_RIGHT_SOCK_SHUTDOWN (UINT64_C(0x0000000010000000))
 #define __WASI_SHUT_RD (UINT8_C(0x01))
 #define __WASI_SHUT_WR (UINT8_C(0x02))
 #define __WASI_SIGABRT (UINT8_C(6))
@@ -3591,7 +3592,6 @@
 #define __WASI_SOCK_RECV_PEEK (UINT16_C(0x0001))
 #define __WASI_SOCK_RECV_WAITALL (UINT16_C(0x0002))
 #define __WASI_SUBSCRIPTION_CLOCK_ABSTIME (UINT16_C(0x0001))
-#define __WASI_UNLINK_REMOVEDIR (UINT8_C(0x01))
 #define __WASI_WHENCE_CUR (UINT8_C(0))
 #define __WASI_WHENCE_END (UINT8_C(1))
 #define __WASI_WHENCE_SET (UINT8_C(2))

expected/wasm32-wasi/undefined-symbols.txt

@@ -50,7 +50,8 @@ __wasi_file_rename
 __wasi_file_stat_get
 __wasi_file_stat_set_times
 __wasi_file_symlink
-__wasi_file_unlink
+__wasi_file_unlink_directory
+__wasi_file_unlink_file
 __wasi_poll_oneoff
 __wasi_proc_exit
 __wasi_random_get

libc-bottom-half/cloudlibc/src/libc/unistd/unlinkat.c

@@ -11,6 +11,7 @@
 #include <unistd.h>
 
 int unlinkat(int fd, const char *path, int flag) {
+#ifdef __wasilibc_unmodified_upstream // unlink
   __wasi_ulflags_t ulflags = 0;
   if ((flag & AT_REMOVEDIR) != 0)
     ulflags |= __WASI_UNLINK_REMOVEDIR;
@@ -20,5 +21,22 @@ int unlinkat(int fd, const char *path, int flag) {
     errno = errno_fixup_directory(fd, error);
     return -1;
   }
+#else
+  __wasi_errno_t error;
+  size_t path_len = strlen(path);
+  if ((flag & AT_REMOVEDIR) != 0) {
+    error = __wasi_file_unlink_directory(fd, path, path_len);
+    if (error != 0) {
+      errno = errno_fixup_directory(fd, error);
+      return -1;
+    }
+  } else {
+    error = __wasi_file_unlink_file(fd, path, path_len);
+    if (error != 0) {
+      errno = error;
+      return -1;
+    }
+  }
+#endif
   return 0;
 }

libc-bottom-half/headers/public/wasi/core.h

@@ -211,9 +211,10 @@ typedef uint64_t __wasi_rights_t;
 #define __WASI_RIGHT_FILE_FSTAT_SET_SIZE   (UINT64_C(0x0000000000400000))
 #define __WASI_RIGHT_FILE_FSTAT_SET_TIMES  (UINT64_C(0x0000000000800000))
 #define __WASI_RIGHT_FILE_SYMLINK          (UINT64_C(0x0000000001000000))
-#define __WASI_RIGHT_FILE_UNLINK           (UINT64_C(0x0000000002000000))
-#define __WASI_RIGHT_POLL_FD_READWRITE     (UINT64_C(0x0000000004000000))
-#define __WASI_RIGHT_SOCK_SHUTDOWN         (UINT64_C(0x0000000008000000))
+#define __WASI_RIGHT_FILE_UNLINK_FILE      (UINT64_C(0x0000000002000000))
+#define __WASI_RIGHT_FILE_UNLINK_DIRECTORY (UINT64_C(0x0000000004000000))
+#define __WASI_RIGHT_POLL_FD_READWRITE     (UINT64_C(0x0000000008000000))
+#define __WASI_RIGHT_SOCK_SHUTDOWN         (UINT64_C(0x0000000010000000))
 
 typedef uint16_t __wasi_roflags_t;
 #define __WASI_SOCK_RECV_DATA_TRUNCATED (UINT16_C(0x0001))
@@ -262,9 +263,6 @@ typedef uint16_t __wasi_subclockflags_t;
 
 typedef uint64_t __wasi_timestamp_t;
 
-typedef uint8_t __wasi_ulflags_t;
-#define __WASI_UNLINK_REMOVEDIR (UINT8_C(0x01))
-
 typedef uint64_t __wasi_userdata_t;
 
 typedef uint8_t __wasi_whence_t;
@@ -624,12 +622,17 @@ __wasi_errno_t __wasi_file_symlink(
     size_t new_path_len
 ) __WASI_SYSCALL_NAME(file_symlink) __attribute__((__warn_unused_result__));
 
-__wasi_errno_t __wasi_file_unlink(
+__wasi_errno_t __wasi_file_unlink_file(
     __wasi_fd_t fd,
     const char *path,
-    size_t path_len,
-    __wasi_ulflags_t flags
-) __WASI_SYSCALL_NAME(file_unlink) __attribute__((__warn_unused_result__));
+    size_t path_len
+) __WASI_SYSCALL_NAME(file_unlink_file) __attribute__((__warn_unused_result__));
+
+__wasi_errno_t __wasi_file_unlink_directory(
+    __wasi_fd_t fd,
+    const char *path,
+    size_t path_len
+) __WASI_SYSCALL_NAME(file_unlink_directory) __attribute__((__warn_unused_result__));
 
 __wasi_errno_t __wasi_poll_oneoff(
     const __wasi_subscription_t *in,