File#path: Raise IOError when a file is O_TMPFILE

File#path for a file opened with O_TMPFILE has no meaning.

A filepath returned by this method isn't guarranteed about its accuracy,
but files opened with O_TMPFILE are known its recorded path has no
meaning. So let them not to return any pathname.

After a discussion in ruby-core, just returning Qnil makes guessing the
root cause difficult. Instead, this patch makes the method to raise an
error.

Other consideration is calling fnctl(2) on rb_file_path, but it adds a
overhead, and it's difficult to determine O_TMPFILE status  after fd has
been closed.

[Feature #13568]

* io.c(rb_file_open_generic): Set Qnil to fptr->pathv when opening a
  file using O_TMPFILE

* file.c(rb_file_path): Raise IOError when fptr->pathv is Qnil

* file.c(rb_file_path): [DOC] Update for the new behavior

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59704 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 10 insertions, 2 deletions

diff --git a/io.c b/io.c
index b8964e8606..0f6afb7bc4 100644
--- a/io.c
+++ b/io.c
@@ -5833,6 +5833,7 @@ static VALUE
 rb_file_open_generic(VALUE io, VALUE filename, int oflags, int fmode,
 		     const convconfig_t *convconfig, mode_t perm)
 {
+    VALUE pathv;
     rb_io_t *fptr;
     convconfig_t cc;
     if (!convconfig) {
@@ -5848,8 +5849,15 @@ rb_file_open_generic(VALUE io, VALUE filename, int oflags, int fmode,
     MakeOpenFile(io, fptr);
     fptr->mode = fmode;
     fptr->encs = *convconfig;
-    fptr->pathv = rb_str_new_frozen(filename);
-    fptr->fd = rb_sysopen(fptr->pathv, oflags, perm);
+    pathv = rb_str_new_frozen(filename);
+#ifdef O_TMPFILE
+    if (!(oflags & O_TMPFILE)) {
+        fptr->pathv = pathv;
+    }
+#else
+    fptr->pathv = pathv;
+#endif
+    fptr->fd = rb_sysopen(pathv, oflags, perm);
     io_check_tty(fptr);
     if (fmode & FMODE_SETENC_BY_BOM) io_set_encoding_by_bom(io);