[xemacs-hg @ 2001-09-20 06:28:42 by ben] The great integral types renaming. The purpose of this is to rationalize the names used for various integral types, so that they match their intended uses and follow consist conventions, and eliminate types that were not semantically different from each other. The conventions are: -- All integral types that measure quantities of anything are signed. Some people disagree vociferously with this, but their arguments are mostly theoretical, and are vastly outweighed by the practical headaches of mixing signed and unsigned values, and more importantly by the far increased likelihood of inadvertent bugs: Because of the broken "viral" nature of unsigned quantities in C (operations involving mixed signed/unsigned are done unsigned, when exactly the opposite is nearly always wanted), even a single error in declaring a quantity unsigned that should be signed, or even the even more subtle error of comparing signed and unsigned values and forgetting the necessary cast, can be catastrophic, as comparisons will yield wrong results. -Wsign-compare is turned on specifically to catch this, but this tends to result in a great number of warnings when mixing signed and unsigned, and the casts are annoying. More has been written on this elsewhere. -- All such quantity types just mentioned boil down to EMACS_INT, which is 32 bits on 32-bit machines and 64 bits on 64-bit machines. This is guaranteed to be the same size as Lisp objects of type `int', and (as far as I can tell) of size_t (unsigned!) and ssize_t. The only type below that is not an EMACS_INT is Hashcode, which is an unsigned value of the same size as EMACS_INT. -- Type names should be relatively short (no more than 10 characters or so), with the first letter capitalized and no underscores if they can at all be avoided. -- "count" == a zero-based measurement of some quantity. Includes sizes, offsets, and indexes. -- "bpos" == a one-based measurement of a position in a buffer. "Charbpos" and "Bytebpos" count text in the buffer, rather than bytes in memory; thus Bytebpos does not directly correspond to the memory representation. Use "Membpos" for this. -- "Char" refers to internal-format characters, not to the C type "char", which is really a byte. -- For the actual name changes, see the script below. I ran the following script to do the conversion. (NOTE: This script is idempotent. You can safely run it multiple times and it will not screw up previous results -- in fact, it will do nothing if nothing has changed. Thus, it can be run repeatedly as necessary to handle patches coming in from old workspaces, or old branches.) There are two tags, just before and just after the change: `pre-integral-type-rename' and `post-integral-type-rename'. When merging code from the main trunk into a branch, the best thing to do is first merge up to `pre-integral-type-rename', then apply the script and associated changes, then merge from `post-integral-type-change' to the present. (Alternatively, just do the merging in one operation; but you may then have a lot of conflicts needing to be resolved by hand.) Script `fixtypes.sh' follows: ----------------------------------- cut ------------------------------------ files="*.[ch] s/*.h m/*.h config.h.in ../configure.in Makefile.in.in ../lib-src/*.[ch] ../lwlib/*.[ch]" gr Memory_Count Bytecount $files gr Lstream_Data_Count Bytecount $files gr Element_Count Elemcount $files gr Hash_Code Hashcode $files gr extcount bytecount $files gr bufpos charbpos $files gr bytind bytebpos $files gr memind membpos $files gr bufbyte intbyte $files gr Extcount Bytecount $files gr Bufpos Charbpos $files gr Bytind Bytebpos $files gr Memind Membpos $files gr Bufbyte Intbyte $files gr EXTCOUNT BYTECOUNT $files gr BUFPOS CHARBPOS $files gr BYTIND BYTEBPOS $files gr MEMIND MEMBPOS $files gr BUFBYTE INTBYTE $files gr MEMORY_COUNT BYTECOUNT $files gr LSTREAM_DATA_COUNT BYTECOUNT $files gr ELEMENT_COUNT ELEMCOUNT $files gr HASH_CODE HASHCODE $files ----------------------------------- cut ------------------------------------ `fixtypes.sh' is a Bourne-shell script; it uses 'gr': ----------------------------------- cut ------------------------------------ #!/bin/sh # Usage is like this: # gr FROM TO FILES ... # globally replace FROM with TO in FILES. FROM and TO are regular expressions. # backup files are stored in the `backup' directory. from="$1" to="$2" shift 2 echo ${1+"$@"} | xargs global-replace "s/$from/$to/g" ----------------------------------- cut ------------------------------------ `gr' in turn uses a Perl script to do its real work, `global-replace', which follows: ----------------------------------- cut ------------------------------------ : #-*- Perl -*- ### global-modify --- modify the contents of a file by a Perl expression ## Copyright (C) 1999 Martin Buchholz. ## Copyright (C) 2001 Ben Wing. ## Authors: Martin Buchholz <martin@xemacs.org>, Ben Wing <ben@xemacs.org> ## Maintainer: Ben Wing <ben@xemacs.org> ## Current Version: 1.0, May 5, 2001 # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 2, or (at your option) # any later version. # # This program is distributed in the hope that it will be useful, but # WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU # General Public License for more details. # # You should have received a copy of the GNU General Public License # along with XEmacs; see the file COPYING. If not, write to the Free # Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA # 02111-1307, USA. eval 'exec perl -w -S $0 ${1+"$@"}' if 0; use strict; use FileHandle; use Carp; use Getopt::Long; use File::Basename; (my $myName = $0) =~ s@.*/@@; my $usage=" Usage: $myName [--help] [--backup-dir=DIR] [--line-mode] [--hunk-mode] PERLEXPR FILE ... Globally modify a file, either line by line or in one big hunk. Typical usage is like this: [with GNU print, GNU xargs: guaranteed to handle spaces, quotes, etc. in file names] find . -name '*.[ch]' -print0 | xargs -0 $0 's/\bCONST\b/const/g'\n [with non-GNU print, xargs] find . -name '*.[ch]' -print | xargs $0 's/\bCONST\b/const/g'\n The file is read in, either line by line (with --line-mode specified) or in one big hunk (with --hunk-mode specified; it's the default), and the Perl expression is then evalled with \$_ set to the line or hunk of text, including the terminating newline if there is one. It should destructively modify the value there, storing the changed result in \$_. Files in which any modifications are made are backed up to the directory specified using --backup-dir, or to `backup' by default. To disable this, use --backup-dir= with no argument. Hunk mode is the default because it is MUCH MUCH faster than line-by-line. Use line-by-line only when it matters, e.g. you want to do a replacement only once per line (the default without the `g' argument). Conversely, when using hunk mode, *ALWAYS* use `g'; otherwise, you will only make one replacement in the entire file! "; my %options = (); $Getopt::Long::ignorecase = 0; &GetOptions ( \%options, 'help', 'backup-dir=s', 'line-mode', 'hunk-mode', ); die $usage if $options{"help"} or @ARGV <= 1; my $code = shift; die $usage if grep (-d || ! -w, @ARGV); sub SafeOpen { open ((my $fh = new FileHandle), $_[0]); confess "Can't open $_[0]: $!" if ! defined $fh; return $fh; } sub SafeClose { close $_[0] or confess "Can't close $_[0]: $!"; } sub FileContents { my $fh = SafeOpen ("< $_[0]"); my $olddollarslash = $/; local $/ = undef; my $contents = <$fh>; $/ = $olddollarslash; return $contents; } sub WriteStringToFile { my $fh = SafeOpen ("> $_[0]"); binmode $fh; print $fh $_[1] or confess "$_[0]: $!\n"; SafeClose $fh; } foreach my $file (@ARGV) { my $changed_p = 0; my $new_contents = ""; if ($options{"line-mode"}) { my $fh = SafeOpen $file; while (<$fh>) { my $save_line = $_; eval $code; $changed_p = 1 if $save_line ne $_; $new_contents .= $_; } } else { my $orig_contents = $_ = FileContents $file; eval $code; if ($_ ne $orig_contents) { $changed_p = 1; $new_contents = $_; } } if ($changed_p) { my $backdir = $options{"backup-dir"}; $backdir = "backup" if !defined ($backdir); if ($backdir) { my ($name, $path, $suffix) = fileparse ($file, ""); my $backfulldir = $path . $backdir; my $backfile = "$backfulldir/$name"; mkdir $backfulldir, 0755 unless -d $backfulldir; print "modifying $file (original saved in $backfile)\n"; rename $file, $backfile; } WriteStringToFile ($file, $new_contents); } } ----------------------------------- cut ------------------------------------ In addition to those programs, I needed to fix up a few other things, particularly relating to the duplicate definitions of types, now that some types merged with others. Specifically: 1. in lisp.h, removed duplicate declarations of Bytecount. The changed code should now look like this: (In each code snippet below, the first and last lines are the same as the original, as are all lines outside of those lines. That allows you to locate the section to be replaced, and replace the stuff in that section, verifying that there isn't anything new added that would need to be kept.) --------------------------------- snip ------------------------------------- /* Counts of bytes or chars */ typedef EMACS_INT Bytecount; typedef EMACS_INT Charcount; /* Counts of elements */ typedef EMACS_INT Elemcount; /* Hash codes */ typedef unsigned long Hashcode; /* ------------------------ dynamic arrays ------------------- */ --------------------------------- snip ------------------------------------- 2. in lstream.h, removed duplicate declaration of Bytecount. Rewrote the comment about this type. The changed code should now look like this: --------------------------------- snip ------------------------------------- #endif /* The have been some arguments over the what the type should be that specifies a count of bytes in a data block to be written out or read in, using Lstream_read(), Lstream_write(), and related functions. Originally it was long, which worked fine; Martin "corrected" these to size_t and ssize_t on the grounds that this is theoretically cleaner and is in keeping with the C standards. Unfortunately, this practice is horribly error-prone due to design flaws in the way that mixed signed/unsigned arithmetic happens. In fact, by doing this change, Martin introduced a subtle but fatal error that caused the operation of sending large mail messages to the SMTP server under Windows to fail. By putting all values back to be signed, avoiding any signed/unsigned mixing, the bug immediately went away. The type then in use was Lstream_Data_Count, so that it be reverted cleanly if a vote came to that. Now it is Bytecount. Some earlier comments about why the type must be signed: This MUST BE SIGNED, since it also is used in functions that return the number of bytes actually read to or written from in an operation, and these functions can return -1 to signal error. Note that the standard Unix read() and write() functions define the count going in as a size_t, which is UNSIGNED, and the count going out as an ssize_t, which is SIGNED. This is a horrible design flaw. Not only is it highly likely to lead to logic errors when a -1 gets interpreted as a large positive number, but operations are bound to fail in all sorts of horrible ways when a number in the upper-half of the size_t range is passed in -- this number is unrepresentable as an ssize_t, so code that checks to see how many bytes are actually written (which is mandatory if you are dealing with certain types of devices) will get completely screwed up. --ben */ typedef enum lstream_buffering --------------------------------- snip ------------------------------------- 3. in dumper.c, there are four places, all inside of switch() statements, where XD_BYTECOUNT appears twice as a case tag. In each case, the two case blocks contain identical code, and you should *REMOVE THE SECOND* and leave the first.

This directory tree holds version 21.5 of XEmacs.



*** What is XEmacs?

XEmacs is a powerful, highly customizable open source text editor and
application development system, with full GUI support.  It is protected
under the GNU Public License and related to other versions of Emacs, in
particular GNU Emacs.  Its emphasis is on modern graphical user
interface support and an open software development model, similar to
Linux.  XEmacs has an active development community numbering in the
hundreds (and thousands of active beta testers on top of this), and runs
on all versions of MS Windows, on Linux, and on nearly every other
version of Unix in existence.  Support for XEmacs has been supplied by
Sun Microsystems, University of Illinois, Lucid, ETL/Electrotechnical
Laboratory, Amdahl Corporation, BeOpen, and others, as well as the
unpaid time of a great number of individual developers.



*** What platforms does it run on?

  -- MS Windows (It has been tested on NT, 2000, 95, 98, and ME; you
                 can also compile Cygwin and MinGW versions.)
  -- Unix (It is regularly tested on Linux, Solaris, SunOS, HP/UX,
           FreeBSD, OpenBSD, BSD/OS aka BSDI, Tru64 aka DEC/OSF, SCO5,
           and probably others.  It should work on all versions of Unix
           created in the last 10 years or so, perhaps with a bit of
           work on more obscure platforms to correct bit-rot.  It uses
           a sophisticated configuration system to auto-detect zillions
           of features that are implemented differently in different
           versions of Unix, so it will probably work on your vendor's
           version, possibly with a bit of tweaking, even if we've
           never heard of it.)
  -- MacOS/X (As an X Windows application.  Unfortunately there is no
              support currently for MacOS-specific features.)

  There is also a port of XEmacs 19.14 (an older version, circa 1996)
  for all versions of MacOS, with extensive support for MacOS-specific
  features.  See the FAQ for more details.

  There are rumors of an in-progress port to OS/2.  See the FAQ.

  XEmacs will probably never work on MS/DOS or Windows 3.1, and we're
  not particularly interested in patches for these platforms, as they
  would introduce huge amounts of code clutter due to the woefully
  underfeatured nature of these systems. (See GNU Emacs for a port to
  MS/DOS.)



*** Where's the FAQ?

Look at `man/xemacs-faq.texi'.

For the very latest version, see
http://cvs.xemacs.org/cgi-bin/cvswebxe/xemacs/man/xemacs-faq.texi.



*** Where's the latest version?

For up-to-date information on XEmacs, see http://www.xemacs.org.

To download XEmacs, see http://ftp.xemacs.org/ or
ftp://ftp.xemacs.org/pub/xemacs/.

For the latest experimental sources, see http://cvs.xemacs.org/, which
gives instructions on how to get started with CVS access.

There are numerous mailing lists for discussion of XEmacs.  The
current description of these lists can be found at
http://www.xemacs.org/Lists/, or see `etc/MAILINGLISTS'.  General
discussion of bugs, new features, etc. takes place on
xemacs-beta@xemacs.org.



*** How do I build and install XEmacs?

See the file `etc/NEWS' for information on new features and other
user-visible changes since the last version of XEmacs.

The file `INSTALL' in this directory says how to bring up XEmacs on
Unix and Cygwin, once you have loaded the entire subtree of this
directory.

See the file `nt/README' for instructions on building XEmacs for
Microsoft Windows.

The file 'README.packages' will guide you in the installation of
(essential) add on packages.



*** How do I deal with bugs or with problems building, installing, or running?

The file `PROBLEMS' contains information on many common problems that
occur in building, installing and running XEmacs.

Reports of bugs in XEmacs should be sent to xemacs-beta@xemacs.org.
You can also post to the newsgroup comp.emacs.xemacs (or equivalentlt,
send to the mailing list xemacs@xemacs.org), but it is less likely
that the developers will see it in a timely fashion.  See the "Bugs"
section of the XEmacs manual for more information on how to report
bugs.  (The file `BUGS' in this directory explains how you can find
and read that section using the Info files that come with XEmacs.)
See `etc/MAILINGLISTS' for more information on mailing lists relating
to XEmacs.


*** What's the basic layout of the code?

The file `configure' is a shell script to acclimate XEmacs to the
oddities of your processor and operating system.  It will create a
file named `Makefile' (a script for the `make' program), which helps
automate the process of building and installing emacs.  See INSTALL
for more detailed information.

The file `configure.in' is the input used by the autoconf program to
construct the `configure' script.  Since XEmacs has configuration
requirements that autoconf can't meet, `configure.in' uses an unholy
marriage of custom-baked configuration code and autoconf macros; it
may be wise to avoid rebuilding `configure' from `configure.in' when
possible.

The file `Makefile.in' is a template used by `configure' to create
`Makefile'.

There are several subdirectories:

`src' holds the C code for XEmacs (the XEmacs Lisp interpreter and its
    primitives, the redisplay code, and some basic editing functions).
`lisp' holds the XEmacs Lisp code for XEmacs (most everything else).
`lib-src' holds the source code for some utility programs for use by
    or with XEmacs, like movemail and etags.
`etc' holds miscellaneous architecture-independent data files
    XEmacs uses, like the tutorial text and the Zippy the Pinhead quote
    database.  The contents of the `lisp', `info' and `man'
    subdirectories are architecture-independent too.
`lwlib' holds the C code for the X toolkit objects used by XEmacs.
`info' holds the Info documentation tree for XEmacs.
`man' holds the source code for the XEmacs online documentation.
`nt' holds files used compiling XEmacs under Microsoft Windows.