build-aux/gitlog-to-changelog

   1 #!/bin/sh
   2 #! -*-perl-*-
   3
   4 # Convert git log output to ChangeLog format.
   5
   6 # Copyright (C) 2008-2024 Free Software Foundation, Inc.
   7 #
   8 # This program is free software: you can redistribute it and/or modify
   9 # it under the terms of the GNU General Public License as published by
  10 # the Free Software Foundation, either version 3 of the License, or
  11 # (at your option) any later version.
  12 #
  13 # This program is distributed in the hope that it will be useful,
  14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 # GNU General Public License for more details.
  17 #
  18 # You should have received a copy of the GNU General Public License
  19 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
  20 #
  21 # Written by Jim Meyering
  22
  23 # This is a prologue that allows running a perl script as an executable
  24 # on systems that are compliant to a POSIX version before POSIX:2017.
  25 # On such systems, the usual invocation of an executable through execlp()
  26 # or execvp() fails with ENOEXEC if it is a script that does not start
  27 # with a #! line.  The script interpreter mentioned in the #! line has
  28 # to be /bin/sh, because on GuixSD systems that is the only program that
  29 # has a fixed file name.  The second line is essential for perl and is
  30 # also useful for editing this file in Emacs.  The next two lines below
  31 # are valid code in both sh and perl.  When executed by sh, they re-execute
  32 # the script through the perl program found in $PATH.  The '-x' option
  33 # is essential as well; without it, perl would re-execute the script
  34 # through /bin/sh.  When executed by perl, the next two lines are a no-op.
  35 eval 'exec perl -wSx "$0" "$@"'
  36      if 0;
  37
  38 my $VERSION = '2023-06-24 21:59'; # UTC
  39 # The definition above must lie within the first 8 lines in order
  40 # for the Emacs time-stamp write hook (at end) to update it.
  41 # If you change this file with Emacs, please let the write hook
  42 # do its job.  Otherwise, update this string manually.
  43
  44 use strict;
  45 use warnings;
  46 use Getopt::Long;
  47 use POSIX qw(strftime);
  48
  49 (my $ME = $0) =~ s|.*/||;
  50
  51 # use File::Coda; # https://meyering.net/code/Coda/
  52 END {
  53   defined fileno STDOUT or return;
  54   close STDOUT and return;
  55   warn "$ME: failed to close standard output: $!\n";
  56   $? ||= 1;
  57 }
  58
  59 sub usage ($)
  60 {
  61   my ($exit_code) = @_;
  62   my $STREAM = ($exit_code == 0 ? *STDOUT : *STDERR);
  63   if ($exit_code != 0)
  64     {
  65       print $STREAM "Try '$ME --help' for more information.\n";
  66     }
  67   else
  68     {
  69       print $STREAM <<EOF;
  70 Usage: $ME [OPTIONS] [ARGS]
  71
  72 Convert git log output to ChangeLog format.  If present, any ARGS
  73 are passed to "git log".  To avoid ARGS being parsed as options to
  74 $ME, they may be preceded by '--'.
  75
  76 OPTIONS:
  77
  78    --amend=FILE FILE maps from an SHA1 to perl code (i.e., s/old/new/) that
  79                   makes a change to SHA1's commit log text or metadata.
  80    --append-dot append a dot to the first line of each commit message if
  81                   there is no other punctuation or blank at the end.
  82    --no-cluster never cluster commit messages under the same date/author
  83                   header; the default is to cluster adjacent commit messages
  84                   if their headers are the same and neither commit message
  85                   contains multiple paragraphs.
  86    --srcdir=DIR the root of the source tree, from which the .git/
  87                   directory can be derived.
  88    --since=DATE convert only the logs since DATE;
  89                   the default is to convert all log entries.
  90    --until=DATE convert only the logs older than DATE.
  91    --ignore-matching=PAT ignore commit messages whose first lines match PAT.
  92    --ignore-line=PAT ignore lines of commit messages that match PAT.
  93    --format=FMT set format string for commit subject and body;
  94                   see 'man git-log' for the list of format metacharacters;
  95                   the default is '%s%n%b%n'
  96    --strip-tab  remove one additional leading TAB from commit message lines.
  97    --strip-cherry-pick  remove data inserted by "git cherry-pick";
  98                   this includes the "cherry picked from commit ..." line,
  99                   and the possible final "Conflicts:" paragraph.
 100    --help       display this help and exit
 101    --version    output version information and exit
 102
 103 EXAMPLE:
 104
 105   $ME --since=2008-01-01 > ChangeLog
 106   $ME -- -n 5 foo > last-5-commits-to-branch-foo
 107
 108 SPECIAL SYNTAX:
 109
 110 The following types of strings are interpreted specially when they appear
 111 at the beginning of a log message line.  They are not copied to the output.
 112
 113   Copyright-paperwork-exempt: Yes
 114     Append the "(tiny change)" notation to the usual "date name email"
 115     ChangeLog header to mark a change that does not require a copyright
 116     assignment.
 117   Co-authored-by: Joe User <user\@example.com>
 118     List the specified name and email address on a second
 119     ChangeLog header, denoting a co-author.
 120   Signed-off-by: Joe User <user\@example.com>
 121     These lines are simply elided.
 122
 123 In a FILE specified via --amend, comment lines (starting with "#") are ignored.
 124 FILE must consist of <SHA,CODE+> pairs where SHA is a 40-byte SHA1 (alone on
 125 a line) referring to a commit in the current project, and CODE refers to one
 126 or more consecutive lines of Perl code.  Pairs must be separated by one or
 127 more blank line.
 128
 129 Here is sample input for use with --amend=FILE, from coreutils:
 130
 131 3a169f4c5d9159283548178668d2fae6fced3030
 132 # fix typo in title:
 133 s/all tile types/all file types/
 134
 135 1379ed974f1fa39b12e2ffab18b3f7a607082202
 136 # Due to a bug in vc-dwim, I mis-attributed a patch by Paul to myself.
 137 # Change the author to be Paul.  Note the escaped "@":
 138 s,Jim .*>,Paul Eggert <eggert\\\@cs.ucla.edu>,
 139
 140 EOF
 141     }
 142   exit $exit_code;
 143 }
 144
 145 # If the string $S is a well-behaved file name, simply return it.
 146 # If it contains white space, quotes, etc., quote it, and return the new string.
 147 sub shell_quote($)
 148 {
 149   my ($s) = @_;
 150   if ($s =~ m![^\w+/.,-]!)
 151     {
 152       # Convert each single quote to '\''
 153       $s =~ s/\'/\'\\\'\'/g;
 154       # Then single quote the string.
 155       $s = "'$s'";
 156     }
 157   return $s;
 158 }
 159
 160 sub quoted_cmd(@)
 161 {
 162   return join (' ', map {shell_quote $_} @_);
 163 }
 164
 165 # Parse file F.
 166 # Comment lines (starting with "#") are ignored.
 167 # F must consist of <SHA,CODE+> pairs where SHA is a 40-byte SHA1
 168 # (alone on a line) referring to a commit in the current project, and
 169 # CODE refers to one or more consecutive lines of Perl code.
 170 # Pairs must be separated by one or more blank line.
 171 sub parse_amend_file($)
 172 {
 173   my ($f) = @_;
 174
 175   open F, '<', $f
 176     or die "$ME: $f: failed to open for reading: $!\n";
 177
 178   my $fail;
 179   my $h = {};
 180   my $in_code = 0;
 181   my $sha;
 182   while (defined (my $line = <F>))
 183     {
 184       $line =~ /^\#/
 185         and next;
 186       chomp $line;
 187       $line eq ''
 188         and $in_code = 0, next;
 189
 190       if (!$in_code)
 191         {
 192           $line =~ /^([[:xdigit:]]{40})$/
 193             or (warn "$ME: $f:$.: invalid line; expected an SHA1\n"),
 194               $fail = 1, next;
 195           $sha = lc $1;
 196           $in_code = 1;
 197           exists $h->{$sha}
 198             and (warn "$ME: $f:$.: duplicate SHA1\n"),
 199               $fail = 1, next;
 200         }
 201       else
 202         {
 203           $h->{$sha} ||= '';
 204           $h->{$sha} .= "$line\n";
 205         }
 206     }
 207   close F;
 208
 209   $fail
 210     and exit 1;
 211
 212   return $h;
 213 }
 214
 215 # git_dir_option $SRCDIR
 216 #
 217 # From $SRCDIR, the --git-dir option to pass to git (none if $SRCDIR
 218 # is undef).  Return as a list (0 or 1 element).
 219 sub git_dir_option($)
 220 {
 221   my ($srcdir) = @_;
 222   my @res = ();
 223   if (defined $srcdir)
 224     {
 225       my $qdir = shell_quote $srcdir;
 226       my $cmd = "cd $qdir && git rev-parse --show-toplevel";
 227       my $qcmd = shell_quote $cmd;
 228       my $git_dir = qx($cmd);
 229       defined $git_dir
 230         or die "$ME: cannot run $qcmd: $!\n";
 231       $? == 0
 232         or die "$ME: $qcmd had unexpected exit code or signal ($?)\n";
 233       chomp $git_dir;
 234       push @res, "--git-dir=$git_dir/.git";
 235     }
 236   @res;
 237 }
 238
 239 {
 240   my $since_date;
 241   my $until_date;
 242   my $format_string = '%s%n%b%n';
 243   my $amend_file;
 244   my $append_dot = 0;
 245   my $cluster = 1;
 246   my $ignore_matching;
 247   my $ignore_line;
 248   my $strip_tab = 0;
 249   my $strip_cherry_pick = 0;
 250   my $srcdir;
 251   GetOptions
 252     (
 253      help => sub { usage 0 },
 254      version => sub { print "$ME version $VERSION\n"; exit },
 255      'since=s' => \$since_date,
 256      'until=s' => \$until_date,
 257      'format=s' => \$format_string,
 258      'amend=s' => \$amend_file,
 259      'append-dot' => \$append_dot,
 260      'cluster!' => \$cluster,
 261      'ignore-matching=s' => \$ignore_matching,
 262      'ignore-line=s' => \$ignore_line,
 263      'strip-tab' => \$strip_tab,
 264      'strip-cherry-pick' => \$strip_cherry_pick,
 265      'srcdir=s' => \$srcdir,
 266     ) or usage 1;
 267
 268   defined $since_date
 269     and unshift @ARGV, "--since=$since_date";
 270   defined $until_date
 271     and unshift @ARGV, "--until=$until_date";
 272
 273   # This is a hash that maps an SHA1 to perl code (i.e., s/old/new/)
 274   # that makes a correction in the log or attribution of that commit.
 275   my $amend_code = defined $amend_file ? parse_amend_file $amend_file : {};
 276
 277   my @cmd = ('git',
 278              git_dir_option $srcdir,
 279              qw(log --log-size),
 280              '--pretty=format:%H:%ct  %an  <%ae>%n%n'.$format_string, @ARGV);
 281   open PIPE, '-|', @cmd
 282     or die ("$ME: failed to run '". quoted_cmd (@cmd) ."': $!\n"
 283             . "(Is your Git too old?  Version 1.5.1 or later is required.)\n");
 284
 285   my $prev_multi_paragraph;
 286   my $prev_date_line = '';
 287   my @prev_coauthors = ();
 288   my @skipshas = ();
 289   while (1)
 290     {
 291       defined (my $in = <PIPE>)
 292         or last;
 293       $in =~ /^log size (\d+)$/
 294         or die "$ME:$.: Invalid line (expected log size):\n$in";
 295       my $log_nbytes = $1;
 296
 297       my $log;
 298       my $n_read = read PIPE, $log, $log_nbytes;
 299       $n_read == $log_nbytes
 300         or die "$ME:$.: unexpected EOF\n";
 301
 302       # Extract leading hash.
 303       my ($sha, $rest) = split ':', $log, 2;
 304       defined $sha
 305         or die "$ME:$.: malformed log entry\n";
 306       $sha =~ /^[[:xdigit:]]{40}$/
 307         or die "$ME:$.: invalid SHA1: $sha\n";
 308
 309       my $skipflag = 0;
 310       if (@skipshas)
 311         {
 312           foreach(@skipshas)
 313             {
 314               if ($sha =~ /^$_/)
 315                 {
 316                   $skipflag = $_;
 317                   last;
 318                 }
 319             }
 320         }
 321
 322       # If this commit's log requires any transformation, do it now.
 323       my $code = $amend_code->{$sha};
 324       if (defined $code)
 325         {
 326           eval 'use Safe';
 327           my $s = new Safe;
 328           # Put the unpreprocessed entry into "$_".
 329           $_ = $rest;
 330
 331           # Let $code operate on it, safely.
 332           my $r = $s->reval("$code")
 333             or die "$ME:$.:$sha: failed to eval \"$code\":\n$@\n";
 334
 335           # Note that we've used this entry.
 336           delete $amend_code->{$sha};
 337
 338           # Update $rest upon success.
 339           $rest = $_;
 340         }
 341
 342       # Remove lines inserted by "git cherry-pick".
 343       if ($strip_cherry_pick)
 344         {
 345           $rest =~ s/^\s*Conflicts:\n.*//sm;
 346           $rest =~ s/^\s*\(cherry picked from commit [\da-f]+\)\n//m;
 347         }
 348
 349       my @line = split /[ \t]*\n/, $rest;
 350       my $author_line = shift @line;
 351       defined $author_line
 352         or die "$ME:$.: unexpected EOF\n";
 353       $author_line =~ /^(\d+)  (.*>)$/
 354         or die "$ME:$.: Invalid line "
 355           . "(expected date/author/email):\n$author_line\n";
 356
 357       # Format 'Copyright-paperwork-exempt: Yes' as a standard ChangeLog
 358       # '(tiny change)' annotation.
 359       my $tiny = (grep (/^(?:Copyright-paperwork-exempt|Tiny-change):\s+[Yy]es$/, @line)
 360                   ? '  (tiny change)' : '');
 361
 362       my $date_line = sprintf "%s  %s$tiny\n",
 363         strftime ("%Y-%m-%d", localtime ($1)), $2;
 364
 365       my @coauthors = grep /^Co-authored-by:.*$/, @line;
 366       # Omit meta-data lines we've already interpreted.
 367       @line = grep !/^(?:Signed-off-by:[ ].*>$
 368                        |Co-authored-by:[ ]
 369                        |Copyright-paperwork-exempt:[ ]
 370                        |Tiny-change:[ ]
 371                        )/x, @line;
 372
 373       # Remove leading and trailing blank lines.
 374       if (@line)
 375         {
 376           while ($line[0] =~ /^\s*$/) { shift @line; }
 377           while ($line[$#line] =~ /^\s*$/) { pop @line; }
 378         }
 379
 380       # Handle Emacs gitmerge.el "skipped" commits.
 381       # Yes, this should be controlled by an option.  So sue me.
 382       if ( grep /^(; )?Merge from /, @line )
 383       {
 384           my $found = 0;
 385           foreach (@line)
 386           {
 387               if (grep /^The following commit.*skipped:$/, $_)
 388               {
 389                   $found = 1;
 390                   ## Reset at each merge to reduce chance of false matches.
 391                   @skipshas = ();
 392                   next;
 393               }
 394               if ($found && $_ =~ /^([[:xdigit:]]{7,}) [^ ]/)
 395               {
 396                   push ( @skipshas, $1 );
 397               }
 398           }
 399       }
 400
 401       # Ignore commits that match the --ignore-matching pattern, if specified.
 402       if (defined $ignore_matching && @line && $line[0] =~ /$ignore_matching/)
 403         {
 404           $skipflag = 1;
 405         }
 406       elsif ($skipflag)
 407         {
 408           ## Perhaps only warn if a pattern matches more than once?
 409           warn "$ME: warning: skipping $sha due to $skipflag\n";
 410         }
 411
 412       if (! $skipflag)
 413         {
 414           if (defined $ignore_line && @line)
 415             {
 416               @line = grep ! /$ignore_line/, @line;
 417               while ($line[$#line] =~ /^\s*$/) { pop @line; }
 418             }
 419
 420           # Record whether there are two or more paragraphs.
 421           my $multi_paragraph = grep /^\s*$/, @line;
 422
 423           # Format 'Co-authored-by: A U Thor <email@example.com>' lines in
 424           # standard multi-author ChangeLog format.
 425           for (@coauthors)
 426             {
 427               s/^Co-authored-by:\s*/\t    /;
 428               s/\s*</  </;
 429
 430               /<.*?@.*\..*>/
 431                 or warn "$ME: warning: missing email address for "
 432                   . substr ($_, 5) . "\n";
 433             }
 434
 435           # If clustering of commit messages has been disabled, if this header
 436           # would be different from the previous date/name/etc. header,
 437           # or if this or the previous entry consists of two or more paragraphs,
 438           # then print the header.
 439           if ( ! $cluster
 440               || $date_line ne $prev_date_line
 441               || "@coauthors" ne "@prev_coauthors"
 442               || $multi_paragraph
 443               || $prev_multi_paragraph)
 444             {
 445               $prev_date_line eq ''
 446                 or print "\n";
 447               print $date_line;
 448               @coauthors
 449                 and print join ("\n", @coauthors), "\n";
 450             }
 451           $prev_date_line = $date_line;
 452           @prev_coauthors = @coauthors;
 453           $prev_multi_paragraph = $multi_paragraph;
 454
 455           # If there were any lines
 456           if (@line == 0)
 457             {
 458               warn "$ME: warning: empty commit message:\n"
 459                    . "  commit $sha\n  $date_line\n";
 460             }
 461           else
 462             {
 463               if ($append_dot)
 464                 {
 465                   # If the first line of the message has enough room, then
 466                   if (length $line[0] < 72)
 467                     {
 468                       # append a dot if there is no other punctuation or blank
 469                       # at the end.
 470                       $line[0] =~ /[[:punct:]\s]$/
 471                         or $line[0] .= '.';
 472                     }
 473                 }
 474
 475               # Remove one additional leading TAB from each line.
 476               $strip_tab
 477                 and map { s/^\t// } @line;
 478
 479               # Prefix each non-empty line with a TAB.
 480               @line = map { length $_ ? "\t$_" : '' } @line;
 481
 482               print "\n", join ("\n", @line), "\n";
 483             }
 484         }
 485
 486       defined ($in = <PIPE>)
 487         or last;
 488       $in ne "\n"
 489         and die "$ME:$.: unexpected line:\n$in";
 490     }
 491
 492   close PIPE
 493     or die "$ME: error closing pipe from " . quoted_cmd (@cmd) . "\n";
 494   # FIXME-someday: include $PROCESS_STATUS in the diagnostic
 495
 496   # Complain about any unused entry in the --amend=F specified file.
 497   my $fail = 0;
 498   foreach my $sha (keys %$amend_code)
 499     {
 500       warn "$ME:$amend_file: unused entry: $sha\n";
 501       $fail = 1;
 502     }
 503
 504   exit $fail;
 505 }
 506
 507 # Local Variables:
 508 # mode: perl
 509 # indent-tabs-mode: nil
 510 # eval: (add-hook 'before-save-hook 'time-stamp)
 511 # time-stamp-line-limit: 50
 512 # time-stamp-start: "my $VERSION = '"
 513 # time-stamp-format: "%:y-%02m-%02d %02H:%02M"
 514 # time-stamp-time-zone: "UTC0"
 515 # time-stamp-end: "'; # UTC"
 516 # End: