FM / Automake

/usr/share/automake-1.16/Automake

Name	Size	Mode	Actions
ChannelDefs.pm	10759	0644	edit dl rm
Channels.pm	20473	0644	edit dl rm
Condition.pm	15179	0644	edit dl rm
Config.pm	1496	0644	edit dl rm
Configure_ac.pm	2976	0644	edit dl rm
DisjConditions.pm	14309	0644	edit dl rm
FileUtils.pm	9100	0644	edit dl rm
General.pm	2029	0644	edit dl rm
Getopt.pm	2297	0644	edit dl rm
Item.pm	4131	0644	edit dl rm
ItemDef.pm	1976	0644	edit dl rm
Language.pm	2811	0644	edit dl rm
Location.pm	5501	0644	edit dl rm
Options.pm	11466	0644	edit dl rm
Rule.pm	24175	0644	edit dl rm
RuleDef.pm	2280	0644	edit dl rm
VarDef.pm	8561	0644	edit dl rm
Variable.pm	45975	0644	edit dl rm
Version.pm	3871	0644	edit dl rm
Wrap.pm	3733	0644	edit dl rm
XFile.pm	7463	0644	edit dl rm

Edit: /usr/share/automake-1.16/Automake/Rule.pm (24175B)

# 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 this program.  If not, see <https://www.gnu.org/licenses/>.

package Automake::Rule;

use 5.006;
use strict;
use Carp;

use Automake::Item;
use Automake::RuleDef;
use Automake::ChannelDefs;
use Automake::Channels;
use Automake::Options;
use Automake::Condition qw (TRUE FALSE);
use Automake::DisjConditions;
require Exporter;
use vars '@ISA', '@EXPORT', '@EXPORT_OK';
@ISA = qw/Automake::Item Exporter/;
@EXPORT = qw (reset register_suffix_rule next_in_suffix_chain
	      suffixes rules $KNOWN_EXTENSIONS_PATTERN
	      depend %dependencies %actions register_action
	      accept_extensions
	      reject_rule msg_rule msg_cond_rule err_rule err_cond_rule
	      rule rrule ruledef rruledef);

=head1 NAME

Automake::Rule - support for rules definitions

=head1 SYNOPSIS

use Automake::Rule;
  use Automake::RuleDef;

=head1 DESCRIPTION

This package provides support for Makefile rule definitions.

An C<Automake::Rule> is a rule name associated to possibly
many conditional definitions.  These definitions are instances
of C<Automake::RuleDef>.

Therefore obtaining the value of a rule under a given
condition involves two lookups.  One to look up the rule,
and one to look up the conditional definition:

my $rule = rule $name;
  if ($rule)
    {
      my $def = $rule->def ($cond);
      if ($def)
	{
	  return $def->location;
	}
      ...
    }
  ...

when it is known that the rule and the definition
being looked up exist, the above can be simplified to

return rule ($name)->def ($cond)->location; # do not write this.

but is better written

return rrule ($name)->rdef ($cond)->location;

or even

return rruledef ($name, $cond)->location;

The I<r> variants of the C<rule>, C<def>, and C<ruledef> methods add
an extra test to ensure that the lookup succeeded, and will diagnose
failures as internal errors (with a message which is much more
informative than Perl's warning about calling a method on a
non-object).

=head2 Global variables

=over 4

=cut

my $_SUFFIX_RULE_PATTERN =
  '^(\.[a-zA-Z0-9_(){}$+@\-]+)(\.[a-zA-Z0-9_(){}$+@\-]+)' . "\$";

my @_suffixes = ();
my @_known_extensions_list = ();
my %_rule_dict = ();

# See comments in the implementation of the 'next_in_suffix_chain()'
# variable for details.
my %_suffix_rules;

# Same as $suffix_rules, but records only the default rules
# supplied by the languages Automake supports.
my %_suffix_rules_builtin;

=item C<%dependencies>

Holds the dependencies of targets which dependencies are factored.
Typically, C<.PHONY> will appear in plenty of F<*.am> files, but must
be output once.  Arguably all pure dependencies could be subject to
this factoring, but it is not unpleasant to have paragraphs in
Makefile: keeping related stuff altogether.

=cut

use vars '%dependencies';

=item <%actions>

Holds the factored actions.  Tied to C<%dependencies>, i.e., filled
only when keys exists in C<%dependencies>.

=cut

use vars '%actions';

=item C<$KNOWN_EXTENSIONS_PATTERN>

Pattern that matches all know input extensions (i.e. extensions used
by the languages supported by Automake).  Using this pattern (instead
of '\..*$') to match extensions allows Automake to support dot-less
extensions.

New extensions should be registered with C<accept_extensions>.

=cut

use vars qw ($KNOWN_EXTENSIONS_PATTERN);
$KNOWN_EXTENSIONS_PATTERN = "";

=back

=head2 Error reporting functions

In these functions, C<$rule> can be either a rule name, or
an instance of C<Automake::Rule>.

=over 4

=item C<err_rule ($rule, $message, [%options])>

Uncategorized errors about rules.

=cut

sub err_rule ($$;%)
{
  msg_rule ('error', @_);
}

=item C<err_cond_rule ($cond, $rule, $message, [%options])>

Uncategorized errors about conditional rules.

=cut

sub err_cond_rule ($$$;%)
{
  msg_cond_rule ('error', @_);
}

=item C<msg_cond_rule ($channel, $cond, $rule, $message, [%options])>

Messages about conditional rules.

=cut

sub msg_cond_rule ($$$$;%)
{
  my ($channel, $cond, $rule, $msg, %opts) = @_;
  my $r = ref ($rule) ? $rule : rrule ($rule);
  msg $channel, $r->rdef ($cond)->location, $msg, %opts;
}

=item C<msg_rule ($channel, $targetname, $message, [%options])>

Messages about rules.

=cut

sub msg_rule ($$$;%)
{
  my ($channel, $rule, $msg, %opts) = @_;
  my $r = ref ($rule) ? $rule : rrule ($rule);
  # Don't know which condition is concerned.  Pick any.
  my $cond = $r->conditions->one_cond;
  msg_cond_rule ($channel, $cond, $r, $msg, %opts);
}

=item C<$bool = reject_rule ($rule, $error_msg)>

Bail out with C<$error_msg> if a rule with name C<$rule> has been
defined.

Return true iff C<$rule> is defined.

=cut

sub reject_rule ($$)
{
  my ($rule, $msg) = @_;
  if (rule ($rule))
    {
      err_rule $rule, $msg;
      return 1;
    }
  return 0;
}

=back

=head2 Administrative functions

=over 4

=item C<accept_extensions (@exts)>

Update C<$KNOWN_EXTENSIONS_PATTERN> to recognize the extensions
listed in C<@exts>.  Extensions should contain a dot if needed.

=cut

sub accept_extensions (@)
{
    push @_known_extensions_list, @_;
    $KNOWN_EXTENSIONS_PATTERN =
	'(?:' . join ('|', map (quotemeta, @_known_extensions_list)) . ')';
}

=item C<rules>

Return the list of all L<Automake::Rule> instances.  (I.e., all
rules defined so far.)

=cut

sub rules ()
{
  return values %_rule_dict;
}

=item C<register_action($target, $action)>

Append the C<$action> to C<$actions{$target}> taking care of special
cases.

=cut

sub register_action ($$)
{
  my ($target, $action) = @_;
  if ($actions{$target})
    {
      $actions{$target} .= "\n$action" if $action;
    }
  else
    {
      $actions{$target} = $action;
    }
}

=item C<Automake::Rule::reset>

The I<forget all> function.  Clears all known rules and resets some
other internal data.

=cut

sub reset()
{
  %_rule_dict = ();
  @_suffixes = ();
  %_suffix_rules = %_suffix_rules_builtin;

%dependencies =
    (
     # Texinfoing.
     'dvi'      => [],
     'dvi-am'   => [],
     'pdf'      => [],
     'pdf-am'   => [],
     'ps'       => [],
     'ps-am'    => [],
     'info'     => [],
     'info-am'  => [],
     'html'     => [],
     'html-am'  => [],

# Installing/uninstalling.
     'install-data-am'      => [],
     'install-exec-am'      => [],
     'uninstall-am'         => [],

'install-man'	    => [],
     'uninstall-man'	    => [],

'install-dvi'          => [],
     'install-dvi-am'       => [],
     'install-html'         => [],
     'install-html-am'      => [],
     'install-info'         => [],
     'install-info-am'      => [],
     'install-pdf'          => [],
     'install-pdf-am'       => [],
     'install-ps'           => [],
     'install-ps-am'        => [],

'installcheck-am'      => [],

# Cleaning.
     'clean-am'             => [],
     'mostlyclean-am'       => [],
     'maintainer-clean-am'  => [],
     'distclean-am'         => [],
     'clean'                => [],
     'mostlyclean'          => [],
     'maintainer-clean'     => [],
     'distclean'            => [],

# Tarballing.
     'dist-all'             => [],

'.PHONY'               => [],
     '.PRECIOUS'            => [],
     # Recursive install targets (so "make -n install" works for BSD Make).
     '.MAKE'		    => [],
     );
  %actions = ();
}

=item C<next_in_suffix_chain ($ext1, $ext2)>

Return the target suffix for the next rule to use to reach C<$ext2>
from C<$ext1>, or C<undef> if no such rule exists.

=cut

sub next_in_suffix_chain ($$)
{
  my ($ext1, $ext2) = @_;
  return undef unless (exists $_suffix_rules{$ext1} and
                       exists $_suffix_rules{$ext1}{$ext2});
  return $_suffix_rules{$ext1}{$ext2}[0];
}

=item C<register_suffix_rule ($where, $src, $dest)>

=cut

sub register_suffix_rule ($$$)
{
  my ($where, $src, $dest) = @_;
  my $suffix_rules = $where->{'position'} ? \%_suffix_rules
                                          : \%_suffix_rules_builtin;

verb "Sources ending in $src become $dest";
  push @_suffixes, $src, $dest;

# When transforming sources to objects, Automake uses the
  # %suffix_rules to move from each source extension to
  # '.$(OBJEXT)', not to '.o' or '.obj'.  However some people
  # define suffix rules for '.o' or '.obj', so internally we will
  # consider these extensions equivalent to '.$(OBJEXT)'.  We
  # CANNOT rewrite the target (i.e., automagically replace '.o'
  # and '.obj' by '.$(OBJEXT)' in the output), or warn the user
  # that (s)he'd better use '.$(OBJEXT)', because Automake itself
  # output suffix rules for '.o' or '.obj' ...
  $dest = '.$(OBJEXT)' if ($dest eq '.o' || $dest eq '.obj');

# ----------------------------------------------------------------------
  # The $suffix_rules variable maps the source extension for all suffix
  # rules seen to a hash whose keys are the possible output extensions.
  #
  # Note that this is transitively closed by construction:
  # if we have
  #
  #       exists $suffix_rules{$ext1}{$ext2}
  #    && exists $suffix_rules{$ext2}{$ext3}
  #
  # then we also have
  #
  #       exists $suffix_rules{$ext1}{$ext3}
  #
  # So it's easy to check whether '.foo' can be transformed to
  # '.$(OBJEXT)' by checking whether $suffix_rules{'.foo'}{'.$(OBJEXT)'}
  # exists.  This will work even if transforming '.foo' to '.$(OBJEXT)'
  # involves a chain of several suffix rules.
  #
  # The value of $suffix_rules{$ext1}{$ext2} is a pair [$next_sfx, $dist]
  # where $next_sfx is target suffix for the next rule to use to reach
  # $ext2, and $dist the distance to $ext2.
  # ----------------------------------------------------------------------

# Register $dest as a possible destination from $src.
  # We might have the create the \hash.
  if (exists $suffix_rules->{$src})
    {
      $suffix_rules->{$src}{$dest} = [ $dest, 1 ];
    }
  else
    {
      $suffix_rules->{$src} = { $dest => [ $dest, 1 ] };
    }

# If we know how to transform $dest in something else, then
  # we know how to transform $src in that "something else".
  if (exists $suffix_rules->{$dest})
    {
      for my $dest2 (keys %{$suffix_rules->{$dest}})
	{
	  my $dist = $suffix_rules->{$dest}{$dest2}[1] + 1;
	  # Overwrite an existing $src->$dest2 path only if
	  # the path via $dest which is shorter.
	  if (! exists $suffix_rules->{$src}{$dest2}
	      || $suffix_rules->{$src}{$dest2}[1] > $dist)
	    {
	      $suffix_rules->{$src}{$dest2} = [ $dest, $dist ];
	    }
	}
    }

# Similarly, any extension that can be derived into $src
  # can be derived into the same extensions as $src can.
  my @dest2 = keys %{$suffix_rules->{$src}};
  for my $src2 (keys %$suffix_rules)
    {
      if (exists $suffix_rules->{$src2}{$src})
	{
	  for my $dest2 (@dest2)
	    {
	      my $dist = $suffix_rules->{$src}{$dest2} + 1;
	      # Overwrite an existing $src2->$dest2 path only if
	      # the path via $src is shorter.
	      if (! exists $suffix_rules->{$src2}{$dest2}
		  || $suffix_rules->{$src2}{$dest2}[1] > $dist)
		{
		  $suffix_rules->{$src2}{$dest2} = [ $src, $dist ];
		}
	    }
	}
    }
}

=item C<@list = suffixes>

Return the list of known suffixes.

=cut

sub suffixes ()
{
  return @_suffixes;
}

=item C<rule ($rulename)>

Return the C<Automake::Rule> object for the rule
named C<$rulename> if defined.  Return 0 otherwise.

=cut

sub rule ($)
{
  my ($name) = @_;
  # Strip $(EXEEXT) from $name, so we can diagnose
  # a clash if 'ctags$(EXEEXT):' is redefined after 'ctags:'.
  $name =~ s,\$$EXEEXT$$,,;
  return $_rule_dict{$name} || 0;
}

=item C<ruledef ($rulename, $cond)>

Return the C<Automake::RuleDef> object for the rule named
C<$rulename> if defined in condition C<$cond>.  Return false
if the condition or the rule does not exist.

=cut

sub ruledef ($$)
{
  my ($name, $cond) = @_;
  my $rule = rule $name;
  return $rule && $rule->def ($cond);
}

=item C<rrule ($rulename)

Return the C<Automake::Rule> object for the variable named
C<$rulename>.  Abort with an internal error if the variable was not
defined.

The I<r> in front of C<var> stands for I<required>.  One
should call C<rvar> to assert the rule's existence.

=cut

sub rrule ($)
{
  my ($name) = @_;
  my $r = rule $name;
  prog_error ("undefined rule $name\n" . &rules_dump)
    unless $r;
  return $r;
}

=item C<rruledef ($varname, $cond)>

Return the C<Automake::RuleDef> object for the rule named
C<$rulename> if defined in condition C<$cond>.  Abort with an internal
error if the condition or the rule does not exist.

=cut

sub rruledef ($$)
{
  my ($name, $cond) = @_;
  return rrule ($name)->rdef ($cond);
}

# Create the variable if it does not exist.
# This is used only by other functions in this package.
sub _crule ($)
{
  my ($name) = @_;
  my $r = rule $name;
  return $r if $r;
  return _new Automake::Rule $name;
}

sub _new ($$)
{
  my ($class, $name) = @_;

# Strip $(EXEEXT) from $name, so we can diagnose
  # a clash if 'ctags$(EXEEXT):' is redefined after 'ctags:'.
  (my $keyname = $name) =~ s,\$$EXEEXT$$,,;

my $self = Automake::Item::new ($class, $name);
  $_rule_dict{$keyname} = $self;
  return $self;
}

sub _rule_defn_with_exeext_awareness ($$$)
{
  my ($target, $cond, $where) = @_;

# For now 'foo:' will override 'foo$(EXEEXT):'.  This is temporary,
  # though, so we emit a warning.
  (my $noexe = $target) =~ s/\$$EXEEXT$$//;
  my $noexerule = rule $noexe;
  my $tdef = $noexerule ? $noexerule->def ($cond) : undef;

if ($noexe ne $target
      && $tdef
      && $noexerule->name ne $target)
    {
      # The no-exeext option enables this feature.
      if (! option 'no-exeext')
	{
	  msg ('obsolete', $tdef->location,
	       "deprecated feature: target '$noexe' overrides "
	       . "'$noexe\$(EXEEXT)'\n"
	       . "change your target to read '$noexe\$(EXEEXT)'",
	       partial => 1);
	  msg ('obsolete', $where, "target '$target' was defined here");
	}
    }
    return $tdef;
}

sub _maybe_warn_about_duplicated_target ($$$$$$)
{
  my ($target, $tdef, $source, $owner, $cond, $where) = @_;

my $oldowner  = $tdef->owner;
  # Ok, it's the name target, but the name maybe different because
  # 'foo$(EXEEXT)' and 'foo' have the same key in our table.
  my $oldname = $tdef->name;

# Don't mention true conditions in diagnostics.
  my $condmsg =
    $cond == TRUE ? '' : (" in condition '" . $cond->human . "'");

if ($owner == RULE_USER)
    {
      if ($oldowner == RULE_USER)
        {
          # Ignore '%'-style pattern rules.  We'd need the
          # dependencies to detect duplicates, and they are
          # already diagnosed as unportable by -Wportability.
          if ($target !~ /^[^%]*%[^%]*$/)
            {
              ## FIXME: Presently we can't diagnose duplicate user rules
              ## because we don't distinguish rules with commands
              ## from rules that only add dependencies.  E.g.,
              ##   .PHONY: foo
              ##   .PHONY: bar
              ## is legitimate.  This is checked in the 'phony.sh' test.

# msg ('syntax', $where,
              #      "redefinition of '$target'$condmsg ...", partial => 1);
              # msg_cond_rule ('syntax', $cond, $target,
              #                "... '$target' previously defined here");
            }
        }
      else
        {
          # Since we parse the user Makefile.am before reading
          # the Automake fragments, this condition should never happen.
          prog_error ("user target '$target'$condmsg seen after Automake's"
                      . " definition\nfrom " . $tdef->source);
        }
    }
  else # $owner == RULE_AUTOMAKE
    {
      if ($oldowner == RULE_USER)
        {
          # -am targets listed in %dependencies support a -local
          # variant.  If the user tries to override TARGET or
          # TARGET-am for which there exists a -local variant,
          # just tell the user to use it.
          my $hint = 0;
          my $noam = $target;
          $noam =~ s/-am$//;
          if (exists $dependencies{"$noam-am"})
            {
              $hint = "consider using $noam-local instead of $target";
            }

msg_cond_rule ('override', $cond, $target,
                         "user target '$target' defined here"
                         . "$condmsg ...", partial => 1);
          msg ('override', $where,
               "... overrides Automake target '$oldname' defined here",
               partial => $hint);
          msg_cond_rule ('override', $cond, $target, $hint)
            if $hint;
        }
      else # $oldowner == RULE_AUTOMAKE
        {
          # Automake should ignore redefinitions of its own
          # rules if they came from the same file.  This makes
          # it easier to process a Makefile fragment several times.
          # However it's an error if the target is defined in many
          # files.  E.g., the user might be using bin_PROGRAMS = ctags
          # which clashes with our 'ctags' rule.
          # (It would be more accurate if we had a way to compare
          # the *content* of both rules.  Then $targets_source would
          # be useless.)
          my $oldsource = $tdef->source;
          if (not ($source eq $oldsource && $target eq $oldname))
            {
               msg ('syntax',
                    $where, "redefinition of '$target'$condmsg ...",
                    partial => 1);
               msg_cond_rule ('syntax', $cond, $target,
                              "... '$oldname' previously defined here");
            }
        }
    }
}

# Return the list of conditionals in which the rule was defined.  In case
# an ambiguous conditional definition is detected, return the empty list.
sub _conditionals_for_rule ($$$$)
{
  my ($rule, $owner, $cond, $where) = @_;
  my $target = $rule->name;
  my @conds;
  my ($message, $ambig_cond) = $rule->conditions->ambiguous_p ($target, $cond);

return $cond if !$message; # No ambiguity.

if ($owner == RULE_USER)
    {
      # For user rules, just diagnose the ambiguity.
      msg 'syntax', $where, "$message ...", partial => 1;
      msg_cond_rule ('syntax', $ambig_cond, $target,
                     "... '$target' previously defined here");
      return ();
    }

# FIXME: for Automake rules, we can't diagnose ambiguities yet.
  # The point is that Automake doesn't propagate conditions
  # everywhere.  For instance &handle_PROGRAMS doesn't care if
  # bin_PROGRAMS was defined conditionally or not.
  # On the following input
  #   if COND1
  #   foo:
  #           ...
  #   else
  #   bin_PROGRAMS = foo
  #   endif
  # &handle_PROGRAMS will attempt to define a 'foo:' rule
  # in condition TRUE (which conflicts with COND1).  Fixing
  # this in &handle_PROGRAMS and siblings seems hard: you'd
  # have to explain &file_contents what to do with a
  # condition.  So for now we do our best *here*.  If 'foo:'
  # was already defined in condition COND1 and we want to define
  # it in condition TRUE, then define it only in condition !COND1.
  # (See cond14.sh and cond15.sh for some test cases.)
  @conds = $rule->not_always_defined_in_cond ($cond)->conds;

# No conditions left to define the rule.
  # Warn, because our workaround is meaningless in this case.
  if (scalar @conds == 0)
    {
      msg 'syntax', $where, "$message ...", partial => 1;
      msg_cond_rule ('syntax', $ambig_cond, $target,
                     "... '$target' previously defined here");
      return ();
    }
  return @conds;
}

=item C<@conds = define ($rulename, $source, $owner, $cond, $where)>

Define a new rule.  C<$rulename> is the list of targets.  C<$source>
is the filename the rule comes from.  C<$owner> is the owner of the
rule (C<RULE_AUTOMAKE> or C<RULE_USER>).  C<$cond> is the
C<Automake::Condition> under which the rule is defined.  C<$where> is
the C<Automake::Location> where the rule is defined.

Returns a (possibly empty) list of C<Automake::Condition>s where the
rule's definition should be output.

=cut

sub define ($$$$$)
{
  my ($target, $source, $owner, $cond, $where) = @_;

prog_error "$where is not a reference"
    unless ref $where;
  prog_error "$cond is not a reference"
    unless ref $cond;

# Don't even think about defining a rule in condition FALSE.
  return () if $cond == FALSE;

my $tdef = _rule_defn_with_exeext_awareness ($target, $cond, $where);

# A GNU make-style pattern rule has a single "%" in the target name.
  msg ('portability', $where,
       "'%'-style pattern rules are a GNU make extension")
    if $target =~ /^[^%]*%[^%]*$/;

# See whether this is a duplicated target declaration.
  if ($tdef)
    {
      # Diagnose invalid target redefinitions, if any.  Note that some
      # target redefinitions are valid (e.g., for multiple-targets
      # pattern rules).
      _maybe_warn_about_duplicated_target ($target, $tdef, $source,
                                           $owner, $cond, $where);
      # Return so we don't redefine the rule in our tables, don't check
      # for ambiguous condition, etc.  The rule will be output anyway
      # because '&read_am_file' ignores the return code.
      return ();
    }

my $rule = _crule $target;

# Conditions for which the rule should be defined.  Due to some
  # complications in the automake internals, this aspect is not as
  # obvious as it might be, and in come cases this list must contain
  # other entries in addition to '$cond'.  See the comments in
  # '_conditionals_for_rule' for a rationale.
  my @conds = _conditionals_for_rule ($rule, $owner, $cond, $where);

# Stop if we had ambiguous conditional definitions.
  return unless @conds;

# Finally define this rule.
  for my $c (@conds)
    {
      my $def = new Automake::RuleDef ($target, '', $where->clone,
				       $owner, $source);
      $rule->set ($c, $def);
    }

# We honor inference rules with multiple targets because many
  # makes support this and people use it.  However this is disallowed
  # by POSIX.  We'll print a warning later.
  my $target_count = 0;
  my $inference_rule_count = 0;

for my $t (split (' ', $target))
    {
      ++$target_count;
      # Check if the rule is a suffix rule: either it's a rule for
      # two known extensions...
      if ($t =~ /^($KNOWN_EXTENSIONS_PATTERN)($KNOWN_EXTENSIONS_PATTERN)$/
	  # ...or it's a rule with unknown extensions (i.e., the rule
	  # looks like '.foo.bar:' but '.foo' or '.bar' are not
	  # declared in SUFFIXES and are not known language
	  # extensions).  Automake will complete SUFFIXES from
	  # @suffixes automatically (see handle_footer).
	  || ($t =~ /$_SUFFIX_RULE_PATTERN/o && accept_extensions($1)))
	{
	  ++$inference_rule_count;
	  register_suffix_rule ($where, $1, $2);
	}
    }

# POSIX allows multiple targets before the colon, but disallows
  # definitions of multiple inference rules.  It's also
  # disallowed to mix plain targets with inference rules.
  msg ('portability', $where,
       "inference rules can have only one target before the colon (POSIX)")
    if $inference_rule_count > 0 && $target_count > 1;

return @conds;
}

=item C<depend ($target, @deps)>

Adds C<@deps> to the dependencies of target C<$target>.  This should
be used only with factored targets (those appearing in
C<%dependees>).

=cut

sub depend ($@)
{
  my ($category, @dependees) = @_;
  push (@{$dependencies{$category}}, @dependees);
}

=back

=head1 SEE ALSO

L<Automake::RuleDef>, L<Automake::Condition>,
L<Automake::DisjConditions>, L<Automake::Location>.

=cut

cmd: