[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.

--- a/src/elhash.c	Tue Sep 18 05:06:57 2001 +0000
+++ b/src/elhash.c	Thu Sep 20 06:31:11 2001 +0000
@@ -82,12 +82,12 @@
 struct Lisp_Hash_Table
 {
   struct lcrecord_header header;
-  Element_Count size;
-  Element_Count count;
-  Element_Count rehash_count;
+  Elemcount size;
+  Elemcount count;
+  Elemcount rehash_count;
   double rehash_size;
   double rehash_threshold;
-  Element_Count golden_ratio;
+  Elemcount golden_ratio;
   hash_table_hash_function_t hash_function;
   hash_table_test_function_t test_function;
   hentry *hentries;
@@ -105,7 +105,7 @@
 #define HASH_TABLE_DEFAULT_REHASH_SIZE 1.3
 #define HASH_TABLE_MIN_SIZE 10
 
-#define HASH_CODE(key, ht)						\
+#define HASHCODE(key, ht)						\
   ((((ht)->hash_function ? (ht)->hash_function (key) : LISP_HASH (key))	\
     * (ht)->golden_ratio)						\
    % (ht)->size)
@@ -143,13 +143,13 @@
 #endif
 
 /* Return a suitable size for a hash table, with at least SIZE slots. */
-static Element_Count
-hash_table_size (Element_Count requested_size)
+static Elemcount
+hash_table_size (Elemcount requested_size)
 {
   /* Return some prime near, but greater than or equal to, SIZE.
      Decades from the time of writing, someone will have a system large
      enough that the list below will be too short... */
-  static const Element_Count primes [] =
+  static const Elemcount primes [] =
   {
     19, 29, 41, 59, 79, 107, 149, 197, 263, 347, 457, 599, 787, 1031,
     1361, 1777, 2333, 3037, 3967, 5167, 6719, 8737, 11369, 14783,
@@ -188,7 +188,7 @@
   return !strcmp ((char *) XSTRING_DATA (str1), (char *) XSTRING_DATA (str2));
 }
 
-static Hash_Code
+static Hashcode
 lisp_string_hash (Lisp_Object obj)
 {
   return hash_string (XSTRING_DATA (str), XSTRING_LENGTH (str));
@@ -202,7 +202,7 @@
   return EQ (obj1, obj2) || (FLOATP (obj1) && internal_equal (obj1, obj2, 0));
 }
 
-static Hash_Code
+static Hashcode
 lisp_object_eql_hash (Lisp_Object obj)
 {
   return FLOATP (obj) ? internal_hash (obj, 0) : LISP_HASH (obj);
@@ -214,7 +214,7 @@
   return internal_equal (obj1, obj2, 0);
 }
 
-static Hash_Code
+static Hashcode
 lisp_object_equal_hash (Lisp_Object obj)
 {
   return internal_hash (obj, 0);
@@ -283,7 +283,7 @@
 /* This is not a great hash function, but it _is_ correct and fast.
    Examining all entries is too expensive, and examining a random
    subset does not yield a correct hash function. */
-static Hash_Code
+static Hashcode
 hash_table_hash (Lisp_Object hash_table, int depth)
 {
   return XHASH_TABLE (hash_table)->count;
@@ -434,7 +434,7 @@
 };
 
 const struct lrecord_description hash_table_description[] = {
-  { XD_ELEMENT_COUNT,     offsetof (Lisp_Hash_Table, size) },
+  { XD_ELEMCOUNT,     offsetof (Lisp_Hash_Table, size) },
   { XD_STRUCT_PTR, offsetof (Lisp_Hash_Table, hentries), XD_INDIRECT(0, 1), &hentry_description },
   { XD_LO_LINK,    offsetof (Lisp_Hash_Table, next_weak) },
   { XD_END }
@@ -465,15 +465,15 @@
 static void
 compute_hash_table_derived_values (Lisp_Hash_Table *ht)
 {
-  ht->rehash_count = (Element_Count)
+  ht->rehash_count = (Elemcount)
     ((double) ht->size * ht->rehash_threshold);
-  ht->golden_ratio = (Element_Count)
+  ht->golden_ratio = (Elemcount)
     ((double) ht->size * (.6180339887 / (double) sizeof (Lisp_Object)));
 }
 
 Lisp_Object
 make_standard_lisp_hash_table (enum hash_table_test test,
-			       Element_Count size,
+			       Elemcount size,
 			       double rehash_size,
 			       double rehash_threshold,
 			       enum hash_table_weakness weakness)
@@ -510,7 +510,7 @@
 Lisp_Object
 make_general_lisp_hash_table (hash_table_hash_function_t hash_function,
 			      hash_table_test_function_t test_function,
-			      Element_Count size,
+			      Elemcount size,
 			      double rehash_size,
 			      double rehash_threshold,
 			      enum hash_table_weakness weakness)
@@ -531,7 +531,7 @@
 
   if (size < HASH_TABLE_MIN_SIZE)
     size = HASH_TABLE_MIN_SIZE;
-  ht->size = hash_table_size ((Element_Count) (((double) size / ht->rehash_threshold)
+  ht->size = hash_table_size ((Elemcount) (((double) size / ht->rehash_threshold)
 					+ 1.0));
   ht->count = 0;
 
@@ -551,7 +551,7 @@
 }
 
 Lisp_Object
-make_lisp_hash_table (Element_Count size,
+make_lisp_hash_table (Elemcount size,
 		      enum hash_table_weakness weakness,
 		      enum hash_table_test test)
 {
@@ -581,7 +581,7 @@
   return 0;
 }
 
-static Element_Count
+static Elemcount
 decode_hash_table_size (Lisp_Object obj)
 {
   return NILP (obj) ? HASH_TABLE_DEFAULT_SIZE : XINT (obj);
@@ -956,10 +956,10 @@
 }
 
 static void
-resize_hash_table (Lisp_Hash_Table *ht, Element_Count new_size)
+resize_hash_table (Lisp_Hash_Table *ht, Elemcount new_size)
 {
   hentry *old_entries, *new_entries, *sentinel, *e;
-  Element_Count old_size;
+  Elemcount old_size;
 
   old_size = ht->size;
   ht->size = new_size;
@@ -974,7 +974,7 @@
   for (e = old_entries, sentinel = e + old_size; e < sentinel; e++)
     if (!HENTRY_CLEAR_P (e))
       {
-	hentry *probe = new_entries + HASH_CODE (e->key, ht);
+	hentry *probe = new_entries + HASHCODE (e->key, ht);
 	LINEAR_PROBING_LOOP (probe, new_entries, new_size)
 	  ;
 	*probe = *e;
@@ -985,7 +985,7 @@
 
 /* After a hash table has been saved to disk and later restored by the
    portable dumper, it contains the same objects, but their addresses
-   and thus their HASH_CODEs have changed. */
+   and thus their HASHCODEs have changed. */
 void
 pdump_reorganize_hash_table (Lisp_Object hash_table)
 {
@@ -996,7 +996,7 @@
   for (e = ht->hentries, sentinel = e + ht->size; e < sentinel; e++)
     if (!HENTRY_CLEAR_P (e))
       {
-	hentry *probe = new_entries + HASH_CODE (e->key, ht);
+	hentry *probe = new_entries + HASHCODE (e->key, ht);
 	LINEAR_PROBING_LOOP (probe, new_entries, ht->size)
 	  ;
 	*probe = *e;
@@ -1010,8 +1010,8 @@
 static void
 enlarge_hash_table (Lisp_Hash_Table *ht)
 {
-  Element_Count new_size =
-    hash_table_size ((Element_Count) ((double) ht->size * ht->rehash_size));
+  Elemcount new_size =
+    hash_table_size ((Elemcount) ((double) ht->size * ht->rehash_size));
   resize_hash_table (ht, new_size);
 }
 
@@ -1020,7 +1020,7 @@
 {
   hash_table_test_function_t test_function = ht->test_function;
   hentry *entries = ht->hentries;
-  hentry *probe = entries + HASH_CODE (key, ht);
+  hentry *probe = entries + HASHCODE (key, ht);
 
   LINEAR_PROBING_LOOP (probe, entries, ht->size)
     if (KEYS_EQUAL_P (probe->key, key, test_function))
@@ -1067,7 +1067,7 @@
 static void
 remhash_1 (Lisp_Hash_Table *ht, hentry *entries, hentry *probe)
 {
-  Element_Count size = ht->size;
+  Elemcount size = ht->size;
   CLEAR_HENTRY (probe);
   probe++;
   ht->count--;
@@ -1075,7 +1075,7 @@
   LINEAR_PROBING_LOOP (probe, entries, size)
     {
       Lisp_Object key = probe->key;
-      hentry *probe2 = entries + HASH_CODE (key, ht);
+      hentry *probe2 = entries + HASHCODE (key, ht);
       LINEAR_PROBING_LOOP (probe2, entries, size)
 	if (EQ (probe2->key, key))
 	  /* hentry at probe doesn't need to move. */
@@ -1550,11 +1550,11 @@
 
 /* Return a hash value for an array of Lisp_Objects of size SIZE. */
 
-Hash_Code
+Hashcode
 internal_array_hash (Lisp_Object *arr, int size, int depth)
 {
   int i;
-  Hash_Code hash = 0;
+  Hashcode hash = 0;
   depth++;
 
   if (size <= 5)
@@ -1585,7 +1585,7 @@
    we could still take 5^5 time (a big big number) to compute a
    hash, but practically this won't ever happen. */
 
-Hash_Code
+Hashcode
 internal_hash (Lisp_Object obj, int depth)
 {
   if (depth > 5)
@@ -1629,7 +1629,7 @@
        (object))
 {
   /* This function is pretty 32bit-centric. */
-  Hash_Code hash = internal_hash (object, 0);
+  Hashcode hash = internal_hash (object, 0);
   return Fcons (hash >> 16, hash & 0xffff);
 }
 #endif