[pull] master from ruby:master

compile.c

@@ -358,6 +358,29 @@ static void iseq_add_setlocal(rb_iseq_t *iseq, LINK_ANCHOR *const seq, const NOD
 #define IS_INSN_ID(iobj, insn) (INSN_OF(iobj) == BIN(insn))
 #define IS_NEXT_INSN_ID(link, insn) \
     ((link)->next && IS_INSN((link)->next) && IS_INSN_ID((link)->next, insn))
+#define IS_NEXT_NEXT_INSN_ID(link, insn) \
+    ((link)->next && IS_NEXT_INSN_ID((link)->next, insn))
+
+static inline bool
+IS_INDEPENDENT_INSN(LINK_ELEMENT *link)
+{
+    if (!IS_INSN(link)) {
+        return false;
+    }
+
+    enum ruby_vminsn_type type = INSN_OF(link);
+
+    return (
+        type == BIN(putobject) ||
+        type == BIN(putspecialobject) ||
+        type == BIN(putnil) ||
+        type == BIN(putself) ||
+        type == BIN(duphash) ||
+        type == BIN(getinstancevariable) ||
+        type == BIN(getlocal) ||
+        type == BIN(opt_getconstant_path)
+    );
+}
 
 /* error */
 #if CPDEBUG > 0
@@ -1225,6 +1248,25 @@ ELEM_REMOVE(LINK_ELEMENT *elem)
     }
 }
 
+/*
+ * elem1, elem2 => elem2, elem1
+ */
+static void
+ELEM_SWAP(LINK_ELEMENT *first, LINK_ELEMENT *second)
+{
+    RUBY_ASSERT(first->next == second);
+    RUBY_ASSERT(first == second->prev);
+
+    first->prev->next = second;
+    second->next->prev = first;
+
+    first->next = second->next;
+    second->next = first;
+
+    second->prev = first->prev;
+    first->prev = second;
+}
+
 static LINK_ELEMENT *
 FIRST_ELEMENT(const LINK_ANCHOR *const anchor)
 {
@@ -4253,6 +4295,24 @@ iseq_peephole_optimize(rb_iseq_t *iseq, LINK_ELEMENT *list, const int do_tailcal
         }
     }
 
+   /*
+    *  putself / (or any other independent instruction)
+    *  putnil  / (or any other independent instruction)
+    *  swap
+    * =>
+    *  putnil  / (or any other independent instruction)
+    *  putself / (or any other independent instruction)
+    */
+    if (IS_NEXT_NEXT_INSN_ID(&iobj->link, swap)) {
+        LINK_ELEMENT *first = &iobj->link;
+        LINK_ELEMENT *second = first->next;
+        LINK_ELEMENT *swap = second->next;
+        if (IS_INDEPENDENT_INSN(first) && IS_INDEPENDENT_INSN(second)) {
+            ELEM_REMOVE(swap);
+            ELEM_SWAP(first, second);
+        }
+    }
+
     return COMPILE_OK;
 }
 

doc/file/filesystem_modes.md

@@ -0,0 +1,282 @@
+# Filesystem Modes
+
+A filesystem entry has an integer _mode_ that specifies:
+
+- [Permissions][permissions].
+- [Special bits][special bits].
+- [File type][file type].
+
+## Getting a Mode
+
+You can use method File::Stat#mode to get the mode of a filesystem entry.
+
+Each of these methods returns a File::Stat object for a given filesystem entry.
+The first three follow symbolic links; the others don't:
+
+- File::stat.
+- IO#stat.
+- Pathname#stat.
+- File::lstat.
+- File#lstat.
+- Pathname#lstat.
+
+Once you have the File::Stat object, you can fetch the mode for the entry:
+
+```ruby
+File.stat('README.md').mode.to_s(8) # => "100664"
+File.stat('doc/').mode.to_s(8)      # => "40775"
+```
+
+On this page, we use a helper method to display a mode
+in a convenient form, showing the mode both as an octal integer and a string.
+If you're new to this page, it may be helpful
+to read about the [helper method][helper method] now.
+
+## Setting a Mode
+
+The mode for an entry is initialized when the entry is created:
+
+```ruby
+filepath = '/tmp/t.txt'
+File.write(filepath, 'foo')
+mode(filepath) # => "100664 -rw-rw-r--"
+dirpath = '/tmp/bar'
+Dir.mkdir(dirpath)
+mode(dirpath)  # => "040775 drwxrwxr-x"
+File.unlink(filepath)
+Dir.rmdir(dirpath)
+```
+
+You can use one of these methods to change the [permissions][permissions]
+and [special bits][special bits] (but not the [file type][file type]):
+
+- File::chmod.
+- FileUtils::chmod.
+- FileUtils::chmod_R.
+- File#chmod.
+- Pathname#chmod.
+- FileUtils#chmod.
+- FileUtils#chmod_R.
+
+## Permissions
+
+A filesystem entry has permissions:
+
+- Read: whether the file or directory may be read, and by what processes.
+- Write: whether the file of directory may be written, and by what processes.
+- Execute/search:
+
+    - File: whether the file may be _executed_, and by what processes.
+    - Directory: whether the directory may be _searched_, and by what processes.
+
+For a method that actually creates a file in the underlying filesystem
+(as opposed to merely creating a File object), permissions may be specified;
+the permissions may also be changed:
+
+```ruby
+filepath = '/tmp/t.tmp'
+File.new(filepath, 'w', 0755)
+mode(filepath) # => "100755 -rwxr-xr-x"
+File.chmod(0644, filepath)
+mode(filepath) # => "100644 -rw-r--r--"
+```
+
+For a method that actually creates a directory in the underlying filesystem
+(as opposed to merely creating a Dir object), permissions may be specified;
+the permissions may also be changed:
+
+```ruby
+dirpath = '/tmp/dir'
+Dir.mkdir(dirpath, 0755)
+mode(dirpath) # => "040755 drwxr-xr-x"
+File.chmod(0644, dirpath)
+mode(dirpath) # => "040644 drw-r--r--"
+```
+
+On non-Posix operating systems, permissions may include only read-only or read-write,
+in which case, the remaining permission will resemble typical values.
+On Windows, for instance, the default permissions are `0644`;
+The only change that can be made is to make the file
+read-only, which is reported as `0444`.
+
+### Directory and \File Permissions
+
+Permissions for directories and files include read and write permissions.
+
+The permissions in this table do not involve execute/search,
+and so apply similarly to a directory or a file.
+
+| Octal | \String       | Permissions                              |
+|:-----:|---------------|------------------------------------------|
+| `000` | `'---------'` | No permissions.                          |
+| `400` | `'r--------'` | Owner read-only.                         |
+| `600` | `'rw-------'` | Owner read-write.                        |
+| `644` | `'rw-r--r--'` | Owner read-write; group/world read-only. |
+| `664` | `'rw-rw-r--'` | Owner/group read-write; world read-only. |
+| `666` | `'rw-rw-rw-'` | Owner/group/world read-write.            |
+
+### \File Permissions
+
+Permissions for a file include execute permissions,
+in addition to the read and write permissions seen above.
+
+The permissions in this table, applied to a file, specify execute permissions.
+
+| Octal    | \String       | Permissions                                                  |
+|:--------:|---------------|--------------------------------------------------------------|
+|  `700`   | `'rwx------'` | Owner read-write-execute.                                    |
+|  `750`   | `'rwxr-x---'` | Owner read-write-execute; group read-execute.                |
+|  `755`   | `'rwxr-xr-x'` | Owner read-write-execute; group read-execute; world execute. |
+|  `775`   | `'rwxrwxr-x'` | Owner/group read-write-execute; world read-execute.          |
+|  `777`   | `'rwxrwxrwx'` | Owner/group/world read-write-execute.                        |
+
+### Directory Permissions
+
+Permissions for a directory include search permissions,
+in addition to the read and write permissions seen above.
+
+The permissions in this table, applied to a directory, specify search permissions.
+
+| Octal  | \String       | Permissions                                               |
+|:------:|---------------|-----------------------------------------------------------|
+| `700`  | `'rwx------'` | Owner read-write-search.                                  |
+| `750`  | `'rwxr-x---'` | Owner read-write-search; group read-search.               |
+| `755`  | `'rwxr-xr-x'` | Owner read-write-search; group read-search; world search. |
+| `775`  | `'rwxrwxr-x'` | Owner/group read-write-search; world read-search.         |
+| `777`  | `'rwxrwxrwx'` | Owner/group/world read-write-search.                      |
+
+## Special Bits
+
+The fourth octal digit in a mode represents its special bits:
+
+- Its low-order bit (`1000`) shows whether the [sticky bit][sticky bit]  is set.
+- The next bit (`2000`) shows whether the [setuid bit][setuid bit] is set.
+- The next bit (`4000`) shows whether the [setgid bit][setgid bit] is set.
+
+| Octal   | Meaning                   |
+|:-------:|---------------------------|
+| `0000`  | None.                     |
+| `1000`  | Sticky.                   |
+| `2000`  | Setgid.                   |
+| `3000`  | Setgid + sticky.          |
+| `4000`  | Setuid.                   |
+| `5000`  | Setuid + sticky.          |
+| `6000`  | Setuid + setgid.          |
+| `7000`  | Setuid + setgid + sticky. |
+
+Examples:
+
+```ruby
+File.write(filepath, '')
+File.chmod(00644, filepath)
+mode(filepath) # => "100644 -rw-r--r--"  # No special bits set.
+File.chmod(01644, filepath)
+mode(filepath) # => "101644 -rw-r--r-T"  # 'T' shows that sticky bit is set.
+File.chmod(02644, filepath)
+mode(filepath) # => "102644 -rw-r-Sr--"  # 'S' shows that setuid bit is set.
+File.chmod(04644, filepath)
+mode(filepath) # => "104644 -rwSr--r--"  # 'S' shows that setgid bit is set.
+File.chmod(07644, filepath)
+mode(filepath) # => "107644 -rwSr-Sr-T"  # All set.
+```
+
+In each case, if the execute bit is also set,
+lowercase letters `'t'` and `'s'` are displayed instead of uppercase `'T'` and `'S'`:
+
+```ruby
+File.chmod(00755, filepath)
+mode(filepath) # => "100755 -rwxr-xr-x"
+File.chmod(01755, filepath)
+mode(filepath) # => "101755 -rwxr-xr-t"
+File.chmod(02755, filepath)
+mode(filepath) # => "102755 -rwxr-sr-x"
+File.chmod(04755, filepath)
+mode(filepath) # => "104755 -rwsr-xr-x"
+File.chmod(07755, filepath)
+mode(filepath) # => "107755 -rwsr-sr-t"
+```
+
+## \File Type
+
+The fifth and sixth octal digits in a mode represent a file type:
+
+| Octal    | Character | \File Type        |
+|----------|:---------:|-------------------|
+| `010000` |   `'p'`   | Pipe.             |
+| `020000` |   `'c'`   | Character device. |
+| `040000` |   `'d'`   | Directory.        |
+| `060000` |   `'b'`   | Block device.     |
+| `100000` |   `'-'`   | Regular file.     |
+| `120000` |   `'l'`   | Symbolic link.    |
+| `140000` |   `'s'`   | \Socket.          |
+
+Examples:
+
+```ruby
+File.mkfifo('/tmp/pipe', 0666)
+mode('/tmp/pipe')   # => "010664 prw-rw-r--"  # 01; pipe.
+mode('/dev/tty')    # => "020666 crw-rw-rw-"  # 02; character device.
+mode('doc/')        # => "040775 drwxrwxr-x"  # 04; directory.
+mode('/dev/loop0')  # => "060660 brw-rw----"  # 06; block device.
+mode('README.md')   # => "100664 -rw-rw-r--"  # 10; regular file.
+File.symlink('lib', '/tmp/link')
+mode('/tmp/link')   # => "120777 lrwxrwxrwx"  # 12; symbolic link.
+require 'socket'
+UNIXServer.new('/tmp/socket')
+mode('/tmp/socket') # => "140775 srwxrwxr-x"  # 14; socket.
+File.unlink('/tmp/pipe', '/tmp/link' ,'/tmp/socket')
+```
+
+## Helper Method
+
+On this page, we use a helper method, `mode`, to show the mode information for a given path:
+
+```ruby
+mode('README.md') # => "0100664 -rw-rw-r--"
+mode('/etc')      # => "0040755 drwxr-xr-x"
+```
+
+The [permissions][permissions] are expressed both in:
+
+- The trailing three digits of the octal value (e.g., `755`, `644`).
+
+    - Left digit: owner permissions.
+    - Middle digit: group permissions.
+    - Right digit: world permissions.
+
+- The trailing nine characters of the string string value
+  (e.g., `'rwxr-xr-x'`, `'rw-r--r--'`).
+
+    - Left three characters: owner permissions.
+    - Middle three characters: group permissions.
+    - Right three characters: world permissions.
+
+The [special bits][special bits] are expressed in the fourth digit.
+
+The [file type][file type] is expressed the fifth and sixth digits.
+
+For the code-curious:
+
+```ruby
+# Return a string containing the mode (octal digits and character string)
+# for the given path.
+def mode(path)
+  # Get mode digits from File.lstat.
+  mode_digits = File.lstat(path).inspect.split(', ').select {|s| s.match('mode')}.first.split('=').last
+  # Format to size.
+  formatted_digits = "%06o" % mode_digits
+  # Get mode characters from ls command.
+  mode_characters = `ls -ld #{path}`.split(' ').first
+  # Return both.
+  "#{formatted_digits} #{mode_characters}"
+end
+```
+
+[permissions]:   #permissions
+[special bits]:  #special-bits
+[file type]:     #file-type
+[helper method]: #helper-method
+
+[sticky bit]: https://en.wikipedia.org/wiki/Sticky_bit
+[setuid bit]: https://en.wikipedia.org/wiki/Setuid
+[setgid bit]: https://en.wikipedia.org/wiki/Setuid

ext/io/console/depend

@@ -4,12 +4,11 @@
 console.o: console.c
 # AUTOGENERATED DEPENDENCIES END
 
-win32_vk.inc: win32_vk.list
+win32_vk.inc: win32_vk.list $(srcdir)/extract-vk.rb
 
 .list.inc:
 	( \
-	$(RUBY) -e "ARGF.read.scan(/^\w+,\s*\KVK_\w+/){|n|puts(%Q[#ifndef #{n}\n# define #{n} UNDEFINED_VK\n#endif])}" \
-	$< && \
+	$(RUBY) $(srcdir)/extract-vk.rb $< && \
 	gperf --ignore-case -L ANSI-C -E -C -P -p -j1 -i 1 -g -o -t -K ofs -N console_win32_vk -k* $< \
 	| sed -f $(top_srcdir)/tool/gperf.sed \
 	) > $(@F)