Variable.pm

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Author : Zack Weinberg
Date : 2020-09-11 18:03:19
Hash : 74673d1c
Message : Consistently use ‘our’ instead of ‘use vars’. At file scope of a file containing at most one ‘package’ declaration, ‘use vars’ is exactly equivalent to ‘our’, and the latter is preferred starting with Perl 5.6.0, which happens to be the oldest version we support. (This change has nothing to do with the previous two, but I want to make the same change in Autoconf and that means doing it here for all the files synced from Automake.) (I don’t know why, but this change exposed a latent bug in FileUtils.pm where the last pod block in the file didn’t have a ‘=cut’ delimiter, so the code after it was considered documentation, causing ‘require FileUtils’ to fail.) * lib/Automake/ChannelDefs.pm * lib/Automake/Channels.pm * lib/Automake/Condition.pm * lib/Automake/Configure_ac.pm * lib/Automake/DisjConditions.pm * lib/Automake/FileUtils.pm * lib/Automake/General.pm * lib/Automake/Getopt.pm * lib/Automake/Options.pm * lib/Automake/Rule.pm * lib/Automake/RuleDef.pm * lib/Automake/VarDef.pm * lib/Automake/Variable.pm * lib/Automake/Wrap.pm * lib/Automake/XFile.pm: Replace all uses of ‘use vars’ with ‘our’. * lib/Automake/FileUtils.pm: Add missing ‘=cut’ to a pod block near the end of the file.
lib/Automake/Variable.pm
# Copyright (C) 2003-2020 Free Software Foundation, Inc.

# 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::Variable;

use 5.006;
use strict;
use warnings FATAL => 'all';

use Carp;
use Exporter;

use Automake::Channels;
use Automake::ChannelDefs;
use Automake::Configure_ac;
use Automake::Item;
use Automake::VarDef;
use Automake::Condition qw (TRUE FALSE);
use Automake::DisjConditions;
use Automake::General 'uniq';
use Automake::Wrap 'makefile_wrap';

our @ISA = qw (Automake::Item Exporter);
our @EXPORT = qw (err_var msg_var msg_cond_var reject_var
		  var rvar vardef rvardef
		  variables
		  scan_variable_expansions check_variable_expansions
		  variable_delete
		  variables_dump
		  set_seen
		  require_variables
		  variable_value
		  output_variables
		  transform_variable_recursively);

=head1 NAME

Automake::Variable - support for variable definitions

=head1 SYNOPSIS

  use Automake::Variable;
  use Automake::VarDef;

  # Defining a variable.
  Automake::Variable::define($varname, $owner, $type,
                             $cond, $value, $comment,
                             $where, $pretty)

  # Looking up a variable.
  my $var = var $varname;
  if ($var)
    {
      ...
    }

  # Looking up a variable that is assumed to exist.
  my $var = rvar $varname;

  # The list of conditions where $var has been defined.
  # ($var->conditions is an Automake::DisjConditions,
  # $var->conditions->conds is a list of Automake::Condition.)
  my @conds = $var->conditions->conds

  # Access to the definition in Condition $cond.
  # $def is an Automake::VarDef.
  my $def = $var->def ($cond);
  if ($def)
    {
      ...
    }

  # When the conditional definition is assumed to exist, use
  my $def = $var->rdef ($cond);


=head1 DESCRIPTION

This package provides support for Makefile variable definitions.

An C<Automake::Variable> is a variable name associated to possibly
many conditional definitions.  These definitions are instances
of C<Automake::VarDef>.

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

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

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

  return var ($name)->def ($cond)->value; # Do not write this.

but is better written

  return rvar ($name)->rdef ($cond)->value;

or even

  return rvardef ($name, $cond)->value;

The I<r> variants of the C<var>, C<def>, and C<vardef> 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).

=cut

my $_VARIABLE_CHARACTERS = '[.A-Za-z0-9_@]+';
my $_VARIABLE_PATTERN = '^' . $_VARIABLE_CHARACTERS . "\$";
my $_VARIABLE_RECURSIVE_PATTERN =
    '^([.A-Za-z0-9_@]|\$[({]' . $_VARIABLE_CHARACTERS . '[})]?)+' . "\$";

# The order in which variables should be output.  (May contain
# duplicates -- only the first occurrence matters.)
my @_var_order;

# This keeps track of all variables defined by &_gen_varname.
# $_gen_varname{$base} is a hash for all variables defined with
# prefix '$base'.  Values stored in this hash are the variable names.
# Keys have the form "(COND1)VAL1(COND2)VAL2..." where VAL1 and VAL2
# are the values of the variable for condition COND1 and COND2.
my %_gen_varname = ();
# $_gen_varname_n{$base} is the number of variables generated by
# _gen_varname() for $base.  This is not the same as keys
# %{$_gen_varname{$base}} because %_gen_varname may also contain
# variables not generated by _gen_varname.
my %_gen_varname_n = ();

# Declare the macros that define known variables, so we can
# hint the user if she try to use one of these variables.

# Macros accessible via aclocal.
my %_am_macro_for_var =
  (
   CCAS => 'AM_PROG_AS',
   CCASFLAGS => 'AM_PROG_AS',
   EMACS => 'AM_PATH_LISPDIR',
   GCJ => 'AM_PROG_GCJ',
   LEX => 'AM_PROG_LEX',
   LIBTOOL => 'LT_INIT',
   lispdir => 'AM_PATH_LISPDIR',
   pkgpyexecdir => 'AM_PATH_PYTHON',
   pkgpythondir => 'AM_PATH_PYTHON',
   pyexecdir => 'AM_PATH_PYTHON',
   PYTHON => 'AM_PATH_PYTHON',
   pythondir => 'AM_PATH_PYTHON',
   );

# Macros shipped with Autoconf.
my %_ac_macro_for_var =
  (
   ALLOCA => 'AC_FUNC_ALLOCA',
   CC => 'AC_PROG_CC',
   CFLAGS => 'AC_PROG_CC',
   CXX => 'AC_PROG_CXX',
   CXXFLAGS => 'AC_PROG_CXX',
   F77 => 'AC_PROG_F77',
   FFLAGS => 'AC_PROG_F77',
   FC => 'AC_PROG_FC',
   FCFLAGS => 'AC_PROG_FC',
   OBJC => 'AC_PROG_OBJC',
   OBJCFLAGS => 'AC_PROG_OBJC',
   OBJCXX => 'AC_PROG_OBJCXX',
   OBJCXXFLAGS => 'AC_PROG_OBJCXX',
   RANLIB => 'AC_PROG_RANLIB',
   UPC => 'AM_PROG_UPC',
   UPCFLAGS => 'AM_PROG_UPC',
   YACC => 'AC_PROG_YACC',
   );

# The name of the configure.ac file.
my $configure_ac;

# Variables that can be overridden without complaint from -Woverride
my %_silent_variable_override =
  (AM_DISTCHECK_DVI_TARGET => 1,
   AM_MAKEINFOHTMLFLAGS => 1,
   AR => 1,
   ARFLAGS => 1,
   DEJATOOL => 1,
   JAVAC => 1,
   JAVAROOT => 1);

# Count of helper variables used to implement conditional '+='.
my $_appendvar;

# Each call to C<Automake::Variable::traverse_recursively> gets an
# unique label. This is used to detect recursively defined variables.
my $_traversal = 0;


=head2 Error reporting functions

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

=over 4

=item C<err_var ($var, $message, [%options])>

Uncategorized errors about variables.

=cut

sub err_var ($$;%)
{
  msg_var ('error', @_);
}

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

Messages about conditional variable.

=cut

sub msg_cond_var ($$$$;%)
{
  my ($channel, $cond, $var, $msg, %opts) = @_;
  my $v = ref ($var) ? $var : rvar ($var);
  msg $channel, $v->rdef ($cond)->location, $msg, %opts;
}

=item C<msg_var ($channel, $var, $message, [%options])>

Messages about variables.

=cut

sub msg_var ($$$;%)
{
  my ($channel, $var, $msg, %opts) = @_;
  my $v = ref ($var) ? $var : rvar ($var);
  # Don't know which condition is concerned.  Pick any.
  my $cond = $v->conditions->one_cond;
  msg_cond_var $channel, $cond, $v, $msg, %opts;
}

=item C<$bool = reject_var ($varname, $error_msg)>

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

Return true iff C<$varname> is defined.

=cut

sub reject_var ($$)
{
  my ($var, $msg) = @_;
  my $v = var ($var);
  if ($v)
    {
      err_var $v, $msg;
      return 1;
    }
  return 0;
}

=back

=head2 Administrative functions

=over 4

=item C<Automake::Variable::hook ($varname, $fun)>

Declare a function to be called whenever a variable
named C<$varname> is defined or redefined.

C<$fun> should take two arguments: C<$type> and C<$value>.
When type is C<''> or <':'>, C<$value> is the value being
assigned to C<$varname>.  When C<$type> is C<'+'>, C<$value>
is the value being appended to  C<$varname>.

=cut

our %_hooks;
sub hook ($$)
{
  my ($var, $fun) = @_;
  $_hooks{$var} = $fun;
}

=item C<variables ([$suffix])>

Returns the list of all L<Automake::Variable> instances.  (I.e., all
variables defined so far.)  If C<$suffix> is supplied, return only
the L<Automake::Variable> instances that ends with C<_$suffix>.

=cut

our (%_variable_dict, %_primary_dict);
sub variables (;$)
{
  my ($suffix) = @_;
  my @vars = ();
  if ($suffix)
    {
      if (exists $_primary_dict{$suffix})
	{
	  @vars = values %{$_primary_dict{$suffix}};
	}
    }
  else
    {
      @vars = values %_variable_dict;
    }
  # The behaviour of the 'sort' built-in is undefined in scalar
  # context, hence we need an ad-hoc handling for such context.
  return wantarray ? sort { $a->name cmp $b->name } @vars : scalar @vars;
}

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

The I<forget all> function.  Clears all know variables and reset some
other internal data.

=cut

sub reset ()
{
  %_variable_dict = ();
  %_primary_dict = ();
  $_appendvar = 0;
  @_var_order = ();
  %_gen_varname = ();
  %_gen_varname_n = ();
  $_traversal = 0;
}

=item C<var ($varname)>

Return the C<Automake::Variable> object for the variable
named C<$varname> if defined.  Return 0 otherwise.

=cut

sub var ($)
{
  my ($name) = @_;
  return $_variable_dict{$name} if exists $_variable_dict{$name};
  return 0;
}

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

Return the C<Automake::VarDef> object for the variable named
C<$varname> if defined in condition C<$cond>.  Return false
if the condition or the variable does not exist.

=cut

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

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

=item C<rvar ($varname)>

Return the C<Automake::Variable> object for the variable named
C<$varname>.  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 variable's existence.

=cut

sub rvar ($)
{
  my ($name) = @_;
  my $v = var $name;
  prog_error ("undefined variable $name\n" . &variables_dump)
    unless $v;
  return $v;
}

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

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

=cut

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

=back

=head2 Methods

C<Automake::Variable> is a subclass of C<Automake::Item>.  See
that package for inherited methods.

Here are the methods specific to the C<Automake::Variable> instances.
Use the C<define> function, described latter, to create such objects.

=over 4

=cut

# Create Automake::Variable objects.  This is used
# only in this file.  Other users should use
# the "define" function.
sub _new ($$)
{
  my ($class, $name) = @_;
  my $self = Automake::Item::new ($class, $name);
  $self->{'scanned'} = 0;
  $self->{'last-append'} = []; # helper variable for last conditional append.
  $_variable_dict{$name} = $self;
  if ($name =~ /_([[:alnum:]]+)$/)
    {
      $_primary_dict{$1}{$name} = $self;
    }
  return $self;
}

# _check_ambiguous_condition ($SELF, $COND, $WHERE)
# -------------------------------------------------
# Check for an ambiguous conditional.  This is called when a variable
# is being defined conditionally.  If we already know about a
# definition that is true under the same conditions, then we have an
# ambiguity.
sub _check_ambiguous_condition ($$$)
{
  my ($self, $cond, $where) = @_;
  my $var = $self->name;
  my ($message, $ambig_cond) = $self->conditions->ambiguous_p ($var, $cond);

  # We allow silent variables to be overridden silently,
  # by either silent or non-silent variables.
  my $def = $self->def ($ambig_cond);
  if ($message && $def->pretty != VAR_SILENT)
    {
      msg 'syntax', $where, "$message ...", partial => 1;
      msg_var ('syntax', $var, "... '$var' previously defined here");
      verb ($self->dump);
    }
}

=item C<$bool = $var-E<gt>check_defined_unconditionally ([$parent, $parent_cond])>

Warn if the variable is conditionally defined.  C<$parent> is the name
of the parent variable, and C<$parent_cond> the condition of the parent
definition.  These two variables are used to display diagnostics.

=cut

sub check_defined_unconditionally ($;$$)
{
  my ($self, $parent, $parent_cond) = @_;

  if (!$self->conditions->true)
    {
      if ($parent)
	{
	  msg_cond_var ('unsupported', $parent_cond, $parent,
			"automake does not support conditional definition of "
			. $self->name . " in $parent");
	}
      else
	{
	  msg_var ('unsupported', $self,
		   "automake does not support " . $self->name
		   . " being defined conditionally");
	}
    }
}

=item C<$str = $var-E<gt>output ([@conds])>

Format all the definitions of C<$var> if C<@cond> is not specified,
else only that corresponding to C<@cond>.

=cut

sub output ($@)
{
  my ($self, @conds) = @_;

  @conds = $self->conditions->conds
    unless @conds;

  my $res = '';
  my $name = $self->name;

  foreach my $cond (@conds)
    {
      my $def = $self->def ($cond);
      prog_error ("unknown condition '" . $cond->human . "' for '"
		  . $self->name . "'")
	unless $def;

      next
	if $def->pretty == VAR_SILENT;

      $res .= $def->comment;

      my $val = $def->raw_value;
      my $equals = $def->type eq ':' ? ':=' : '=';
      my $str = $cond->subst_string;


      if ($def->pretty == VAR_ASIS)
	{
	  my $output_var = "$name $equals $val";
	  $output_var =~ s/^/$str/meg;
	  $res .= "$output_var\n";
	}
      elsif ($def->pretty == VAR_PRETTY)
	{
	  # Suppress escaped new lines.  &makefile_wrap will
	  # add them back, maybe at other places.
	  $val =~ s/\\$//mg;
	  my $wrap = makefile_wrap ("$str$name $equals", "$str\t",
				    split (' ', $val));

	  # If the last line of the definition is made only of
	  # @substitutions@, append an empty variable to make sure it
	  # cannot be substituted as a blank line (that would confuse
	  # HP-UX Make).
	  $wrap = makefile_wrap ("$str$name $equals", "$str\t",
				 split (' ', $val), '$(am__empty)')
	    if $wrap =~ /\n(\s*@\w+@)+\s*$/;

	  $res .= $wrap;
	}
      else # ($def->pretty == VAR_SORTED)
	{
	  # Suppress escaped new lines.  &makefile_wrap will
	  # add them back, maybe at other places.
	  $val =~ s/\\$//mg;
	  $res .= makefile_wrap ("$str$name $equals", "$str\t",
				 sort (split (' ' , $val)));
	}
    }
  return $res;
}

=item C<@values = $var-E<gt>value_as_list ($cond, [$parent, $parent_cond])>

Get the value of C<$var> as a list, given a specified condition,
without recursing through any subvariables.

C<$cond> is the condition of interest.  C<$var> does not need
to be defined for condition C<$cond> exactly, but it needs
to be defined for at most one condition implied by C<$cond>.

C<$parent> and C<$parent_cond> designate the name and the condition
of the parent variable, i.e., the variable in which C<$var> is
being expanded.  These are used in diagnostics.

For example, if C<A> is defined as "C<foo $(B) bar>" in condition
C<TRUE>, calling C<rvar ('A')->value_as_list (TRUE)> will return
C<("foo", "$(B)", "bar")>.

=cut

sub value_as_list ($$;$$)
{
  my ($self, $cond, $parent, $parent_cond) = @_;
  my @result;

  # Get value for given condition
  my $onceflag;
  foreach my $vcond ($self->conditions->conds)
    {
      if ($vcond->true_when ($cond))
	{
	  # If there is more than one definitions of $var matching
	  # $cond then we are in trouble: tell the user we need a
	  # paddle.  Continue by merging results from all conditions,
	  # although it doesn't make much sense.
	  $self->check_defined_unconditionally ($parent, $parent_cond)
	    if $onceflag;
	  $onceflag = 1;

	  my $val = $self->rdef ($vcond)->value;
	  push @result, split (' ', $val);
	}
    }
  return @result;
}

=item C<@values = $var-E<gt>value_as_list_recursive ([%options])>

Return the contents of C<$var> as a list, split on whitespace.  This
will recursively follow C<$(...)> and C<${...}> inclusions.  It
preserves C<@...@> substitutions.

C<%options> is a list of option for C<Variable::traverse_recursively>
(see this method).  The most useful is C<cond_filter>:

  $var->value_as_list_recursive (cond_filter => $cond)

will return the contents of C<$var> and any subvariable in all
conditions implied by C<$cond>.

C<%options> can also carry options specific to C<value_as_list_recursive>.
Presently, the only such option is C<location =E<gt> 1> which instructs
C<value_as_list_recursive> to return a list of C<[$location, @values]> pairs.

=cut

sub value_as_list_recursive ($;%)
{
  my ($var, %options) = @_;

  return $var->traverse_recursively
    (# Construct [$location, $value] pairs if requested.
     sub {
       my ($var, $val, $cond, $full_cond) = @_;
       return [$var->rdef ($cond)->location, $val] if $options{'location'};
       return $val;
     },
     # Collect results.
     sub {
       my ($var, $parent_cond, @allresults) = @_;
       return map { my ($cond, @vals) = @$_; @vals } @allresults;
     },
     %options);
}


=item C<$bool = $var-E<gt>has_conditional_contents>

Return 1 if C<$var> or one of its subvariable was conditionally
defined.  Return 0 otherwise.

=cut

sub has_conditional_contents ($)
{
  my ($self) = @_;

  # Traverse the variable recursively until we
  # find a variable defined conditionally.
  # Use 'die' to abort the traversal, and pass it '$full_cond'
  # to we can find easily whether the 'eval' block aborted
  # because we found a condition, or for some other error.
  eval
    {
      $self->traverse_recursively
	(sub
	 {
	   my ($subvar, $val, $cond, $full_cond) = @_;
	   die $full_cond if ! $full_cond->true;
	   return ();
	 },
	 sub { return (); });
    };
  if ($@)
    {
      return 1 if ref ($@) && $@->isa ("Automake::Condition");
      # Propagate other errors.
      die;
    }
  return 0;
}


=item C<$string = $var-E<gt>dump>

Return a string describing all we know about C<$var>.
For debugging.

=cut

sub dump ($)
{
  my ($self) = @_;

  my $text = $self->name . ": \n  {\n";
  foreach my $vcond ($self->conditions->conds)
    {
      $text .= "    " . $vcond->human . " => " . $self->rdef ($vcond)->dump;
    }
  $text .= "  }\n";
  return $text;
}


=back

=head2 Utility functions

=over 4

=item C<@list = scan_variable_expansions ($text)>

Return the list of variable names expanded in C<$text>.  Note that
unlike some other functions, C<$text> is not split on spaces before we
check for subvariables.

=cut

sub scan_variable_expansions ($)
{
  my ($text) = @_;
  my @result = ();

  # Strip comments.
  $text =~ s/#.*$//;

  # Record each use of ${stuff} or $(stuff) that does not follow a $.
  while ($text =~ /(?<!\$)\$(?:\{([^\}]*)\}|\(([^\)]*)\))/g)
    {
      my $var = $1 || $2;
      # The occurrence may look like $(string1[:subst1=[subst2]]) but
      # we want only 'string1'.
      $var =~ s/:[^:=]*=[^=]*$//;
      push @result, $var;
    }

  return @result;
}

=item C<check_variable_expansions ($text, $where)>

Check variable expansions in C<$text> and warn about any name that
does not conform to POSIX.  C<$where> is the location of C<$text>
for the error message.

=cut

sub check_variable_expansions ($$)
{
  my ($text, $where) = @_;
  # Catch expansion of variables whose name does not conform to POSIX.
  foreach my $var (scan_variable_expansions ($text))
    {
      if ($var !~ /$_VARIABLE_PATTERN/o)
	{
	  # If the variable name contains a space, it's likely
	  # to be a GNU make extension (such as $(addsuffix ...)).
	  # Mention this in the diagnostic.
	  my $gnuext = "";
	  $gnuext = "\n(probably a GNU make extension)" if $var =~ / /;
	  # Accept recursive variable expansions if so desired
	  # (we hope they are rather portable in practice).
	  if ($var =~ /$_VARIABLE_RECURSIVE_PATTERN/o)
	    {
	      msg ('portability-recursive', $where,
		   "$var: non-POSIX recursive variable expansion$gnuext");
	    }
	  else
	    {
	      msg ('portability', $where, "$var: non-POSIX variable name$gnuext");
	    }
	}
    }
}



=item C<Automake::Variable::define($varname, $owner, $type, $cond, $value, $comment, $where, $pretty)>

Define or append to a new variable.

C<$varname>: the name of the variable being defined.

C<$owner>: owner of the variable (one of C<VAR_MAKEFILE>,
C<VAR_CONFIGURE>, or C<VAR_AUTOMAKE>, defined by L<Automake::VarDef>).
Variables can be overridden, provided the new owner is not weaker
(C<VAR_AUTOMAKE> < C<VAR_CONFIGURE> < C<VAR_MAKEFILE>).

C<$type>: the type of the assignment (C<''> for C<FOO = bar>,
C<':'> for C<FOO := bar>, and C<'+'> for C<'FOO += bar'>).

C<$cond>: the C<Condition> in which C<$var> is being defined.

C<$value>: the value assigned to C<$var> in condition C<$cond>.

C<$comment>: any comment (C<'# bla.'>) associated with the assignment.
Comments from C<+=> assignments stack with comments from the last C<=>
assignment.

C<$where>: the C<Location> of the assignment.

C<$pretty>: whether C<$value> should be pretty printed (one of
C<VAR_ASIS>, C<VAR_PRETTY>, C<VAR_SILENT>, or C<VAR_SORTED>, defined
by by L<Automake::VarDef>).  C<$pretty> applies only to real
assignments.  I.e., it does not apply to a C<+=> assignment (except
when part of it is being done as a conditional C<=> assignment).

This function will all run any hook registered with the C<hook>
function.

=cut

sub define ($$$$$$$$)
{
  my ($var, $owner, $type, $cond, $value, $comment, $where, $pretty) = @_;

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

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

  prog_error "pretty argument missing"
    unless defined $pretty && ($pretty == VAR_ASIS
			       || $pretty == VAR_PRETTY
			       || $pretty == VAR_SILENT
			       || $pretty == VAR_SORTED);

  error $where, "bad characters in variable name '$var'"
    if $var !~ /$_VARIABLE_PATTERN/o;

  # ':='-style assignments are not acknowledged by POSIX.  Moreover it
  # has multiple meanings.  In GNU make or BSD make it means "assign
  # with immediate expansion", while in OSF make it is used for
  # conditional assignments.
  msg ('portability', $where, "':='-style assignments are not portable")
    if $type eq ':';

  check_variable_expansions ($value, $where);

  # If there's a comment, make sure it is \n-terminated.
  if ($comment)
    {
      chomp $comment;
      $comment .= "\n";
    }
  else
    {
      $comment = '';
    }

  my $self = _cvar $var;

  my $def = $self->def ($cond);
  my $new_var = $def ? 0 : 1;

  # Additional checks for Automake definitions.
  if ($owner == VAR_AUTOMAKE && ! $new_var)
    {
      # An Automake variable must be consistently defined with the same
      # sign by Automake.
      if ($def->type ne $type && $def->owner == VAR_AUTOMAKE)
	{
	  error ($def->location,
		 "Automake variable '$var' was set with '"
		 . $def->type . "=' here ...", partial => 1);
	  error ($where, "... and is now set with '$type=' here.");
	  prog_error ("Automake variable assignments should be consistently\n"
		      . "defined with the same sign");
	}

      # If Automake tries to override a value specified by the user,
      # just don't let it do.
      if ($def->owner != VAR_AUTOMAKE)
	{
	  if (! exists $_silent_variable_override{$var})
	    {
	      my $condmsg = ($cond == TRUE
			     ? '' : (" in condition '" . $cond->human . "'"));
	      msg_cond_var ('override', $cond, $var,
			    "user variable '$var' defined here$condmsg ...",
			    partial => 1);
	      msg ('override', $where,
		   "... overrides Automake variable '$var' defined here");
	    }
	  verb ("refusing to override the user definition of:\n"
		. $self->dump ."with '" . $cond->human . "' => '$value'");
	  return;
	}
    }

  # Differentiate assignment types.

  # 1. append (+=) to a variable defined for current condition
  if ($type eq '+' && ! $new_var)
    {
      $def->append ($value, $comment);
      $self->{'last-append'} = [];

      # Only increase owners.  A VAR_CONFIGURE variable augmented in a
      # Makefile.am becomes a VAR_MAKEFILE variable.
      $def->set_owner ($owner, $where->clone)
	if $owner > $def->owner;
    }
  # 2. append (+=) to a variable defined for *another* condition
  elsif ($type eq '+' && ! $self->conditions->false)
    {
      # * Generally, $cond is not TRUE.  For instance:
      #     FOO = foo
      #     if COND
      #       FOO += bar
      #     endif
      #   In this case, we declare an helper variable conditionally,
      #   and append it to FOO:
      #     FOO = foo $(am__append_1)
      #     @COND_TRUE@am__append_1 = bar
      #   Of course if FOO is defined under several conditions, we add
      #   $(am__append_1) to each definitions.
      #
      # * If $cond is TRUE, we don't need the helper variable.  E.g., in
      #     if COND1
      #       FOO = foo1
      #     else
      #       FOO = foo2
      #     endif
      #     FOO += bar
      #   we can add bar directly to all definition of FOO, and output
      #     @COND_TRUE@FOO = foo1 bar
      #     @COND_FALSE@FOO = foo2 bar

      my $lastappend = [];
      # Do we need an helper variable?
      if ($cond != TRUE)
        {
	  # Can we reuse the helper variable created for the previous
	  # append?  (We cannot reuse older helper variables because
	  # we must preserve the order of items appended to the
	  # variable.)
	  my $condstr = $cond->string;
	  my $key = "$var:$condstr";
	  my ($appendvar, $appendvarcond) = @{$self->{'last-append'}};
	  if ($appendvar && $condstr eq $appendvarcond)
	    {
	      # Yes, let's simply append to it.
	      $var = $appendvar;
	      $owner = VAR_AUTOMAKE;
	      $self = var ($var);
	      $def = $self->rdef ($cond);
	      $new_var = 0;
	    }
	  else
	    {
	      # No, create it.
	      my $num = ++$_appendvar;
	      my $hvar = "am__append_$num";
	      $lastappend = [$hvar, $condstr];
	      &define ($hvar, VAR_AUTOMAKE, '+',
		       $cond, $value, $comment, $where, $pretty);

	      # Now HVAR is to be added to VAR.
	      $comment = '';
	      $value = "\$($hvar)";
	    }
	}

      # Add VALUE to all definitions of SELF.
      foreach my $vcond ($self->conditions->conds)
        {
	  # We have a bit of error detection to do here.
	  # This:
	  #   if COND1
	  #     X = Y
	  #   endif
	  #   X += Z
	  # should be rejected because X is not defined for all conditions
	  # where '+=' applies.
	  my $undef_cond = $self->not_always_defined_in_cond ($cond);
	  if (! $undef_cond->false)
	    {
	      error ($where,
		     "cannot apply '+=' because '$var' is not defined "
		     . "in\nthe following conditions:\n  "
		     . join ("\n  ", map { $_->human } $undef_cond->conds)
		     . "\neither define '$var' in these conditions,"
		     . " or use\n'+=' in the same conditions as"
		     . " the definitions.");
	    }
	  else
	    {
	      &define ($var, $owner, '+', $vcond, $value, $comment,
		       $where, $pretty);
	    }
	}
      $self->{'last-append'} = $lastappend;
    }
  # 3. first assignment (=, :=, or +=)
  else
    {
      # There must be no previous value unless the user is redefining
      # an Automake variable or an AC_SUBST variable for an existing
      # condition.
      _check_ambiguous_condition ($self, $cond, $where)
	unless (!$new_var
		&& (($def->owner == VAR_AUTOMAKE && $owner != VAR_AUTOMAKE)
		    || $def->owner == VAR_CONFIGURE));

      # Never decrease an owner.
      $owner = $def->owner
	if ! $new_var && $owner < $def->owner;

      # Assignments to a macro set its location.  We don't adjust
      # locations for '+='.  Ideally I suppose we would associate
      # line numbers with random bits of text.
      $def = new Automake::VarDef ($var, $value, $comment, $where->clone,
				   $type, $owner, $pretty);
      $self->set ($cond, $def);
      push @_var_order, $var;
    }

  # Call any defined hook.  This helps to update some internal state
  # *while* parsing the file.  For instance the handling of SUFFIXES
  # requires this (see var_SUFFIXES_trigger).
  &{$_hooks{$var}}($type, $value) if exists $_hooks{$var};
}

=item C<variable_delete ($varname, [@conds])>

Forget about C<$varname> under the conditions C<@conds>, or completely
if C<@conds> is empty.

=cut

sub variable_delete ($@)
{
  my ($var, @conds) = @_;

  if (!@conds)
    {
      delete $_variable_dict{$var};
    }
  else
    {
      for my $cond (@conds)
	{
	  delete $_variable_dict{$var}{'defs'}{$cond};
	}
    }
  if ($var =~ /_([[:alnum:]]+)$/)
    {
      delete $_primary_dict{$1}{$var};
    }
}

=item C<$str = variables_dump>

Return a string describing all we know about all variables.
For debugging.

=cut

sub variables_dump ()
{
  my $text = "all variables:\n{\n";
  foreach my $var (variables())
    {
      $text .= $var->dump;
    }
  $text .= "}\n";
  return $text;
}


=item C<$var = set_seen ($varname)>

=item C<$var = $var-E<gt>set_seen>

Mark all definitions of this variable as examined, if the variable
exists.  See L<Automake::VarDef::set_seen>.

Return the C<Variable> object if the variable exists, or 0
otherwise (i.e., as the C<var> function).

=cut

sub set_seen ($)
{
  my ($self) = @_;
  $self = ref $self ? $self : var $self;

  return 0 unless $self;

  for my $c ($self->conditions->conds)
    {
      $self->rdef ($c)->set_seen;
    }

  return $self;
}


=item C<$count = require_variables ($where, $reason, $cond, @variables)>

Make sure that each supplied variable is defined in C<$cond>.
Otherwise, issue a warning showing C<$reason> (C<$reason> should be
the reason why these variables are required, for instance C<'option foo
used'>).  If we know which macro can define this variable, hint the
user.  Return the number of undefined variables.

=cut

sub require_variables ($$$@)
{
  my ($where, $reason, $cond, @vars) = @_;
  my $res = 0;
  $reason .= ' but ' unless $reason eq '';

  $configure_ac = find_configure_ac
    unless defined $configure_ac;

 VARIABLE:
  foreach my $var (@vars)
    {
      # Nothing to do if the variable exists.
      next VARIABLE
	if vardef ($var, $cond);

      my $text = "$reason'$var' is undefined\n";
      my $v = var $var;
      if ($v)
	{
	  my $undef_cond = $v->not_always_defined_in_cond ($cond);
	  next VARIABLE
	    if $undef_cond->false;
	  $text .= ("in the following conditions:\n  "
		    . join ("\n  ", map { $_->human } $undef_cond->conds)
		    . "\n");
	}

      ++$res;

      if (exists $_am_macro_for_var{$var})
	{
	  my $mac = $_am_macro_for_var{$var};
	  $text .= "  The usual way to define '$var' is to add "
	    . "'$mac'\n  to '$configure_ac' and run 'aclocal' and "
	    . "'autoconf' again.";
	  # aclocal will not warn about undefined macros unless it
	  # starts with AM_.
	  $text .= "\n  If '$mac' is in '$configure_ac', make sure\n"
	    . "  its definition is in aclocal's search path."
	    unless $mac =~ /^AM_/;
	}
      elsif (exists $_ac_macro_for_var{$var})
	{
	  $text .= "  The usual way to define '$var' is to add "
	    . "'$_ac_macro_for_var{$var}'\n  to '$configure_ac' and "
	    . "run 'autoconf' again.";
	}

      error $where, $text, uniq_scope => US_GLOBAL;
    }
  return $res;
}

=item C<$count = $var->requires_variables ($reason, @variables)>

Same as C<require_variables>, but a method of Automake::Variable.
C<@variables> should be defined in the same conditions as C<$var> is
defined.

=cut

sub requires_variables ($$@)
{
  my ($var, $reason, @args) = @_;
  my $res = 0;
  for my $cond ($var->conditions->conds)
    {
      $res += require_variables ($var->rdef ($cond)->location, $reason,
				 $cond, @args);
    }
  return $res;
}


=item C<variable_value ($var)>

Get the C<TRUE> value of a variable, warn if the variable is
conditionally defined.  C<$var> can be either a variable name
or a C<Automake::Variable> instance (this allows calls such
as C<$var-E<gt>variable_value>).

=cut

sub variable_value ($)
{
    my ($var) = @_;
    my $v = ref ($var) ? $var : var ($var);
    return () unless $v;
    $v->check_defined_unconditionally;
    my $d = $v->def (TRUE);
    return $d ? $d->value : "";
}

=item C<$str = output_variables>

Format definitions for all variables.

=cut

sub output_variables ()
{
  my $res = '';
  # We output variables it in the same order in which they were
  # defined (skipping duplicates).
  my @vars = uniq @_var_order;

  # Output all the Automake variables.  If the user changed one,
  # then it is now marked as VAR_CONFIGURE or VAR_MAKEFILE.
  foreach my $var (@vars)
    {
      my $v = rvar $var;
      foreach my $cond ($v->conditions->conds)
	{
	  $res .= $v->output ($cond)
	    if $v->rdef ($cond)->owner == VAR_AUTOMAKE;
	}
    }

  # Now dump the user variables that were defined.
  foreach my $var (@vars)
    {
      my $v = rvar $var;
      foreach my $cond ($v->conditions->conds)
	{
	  $res .= $v->output ($cond)
	    if $v->rdef ($cond)->owner != VAR_AUTOMAKE;
	}
    }
  return $res;
}

=item C<$var-E<gt>traverse_recursively (&fun_item, &fun_collect, [cond_filter =E<gt> $cond_filter], [inner_expand =E<gt> 1], [skip_ac_subst =E<gt> 1])>

Split the value of the Automake::Variable C<$var> on space, and
traverse its components recursively.

If C<$cond_filter> is an C<Automake::Condition>, process any
conditions which are true when C<$cond_filter> is true.  Otherwise,
process all conditions.

We distinguish two kinds of items in the content of C<$var>.
Terms that look like C<$(foo)> or C<${foo}> are subvariables
and cause recursion.  Other terms are assumed to be filenames.

Each time a filename is encountered, C<&fun_item> is called with the
following arguments:

  ($var,        -- the Automake::Variable we are currently
                   traversing
   $val,        -- the item (i.e., filename) to process
   $cond,       -- the Condition for the $var definition we are
                   examining (ignoring the recursion context)
   $full_cond)  -- the full Condition, taking into account
                   conditions inherited from parent variables
                   during recursion

If C<inner_expand> is set, variable references occurring in filename
(as in C<$(BASE).ext>) are expanded before the filename is passed to
C<&fun_item>.

If C<skip_ac_subst> is set, Autoconf @substitutions@ will be skipped,
i.e., C<&fun_item> will never be called for them.

C<&fun_item> may return a list of items, they will be passed to
C<&fun_store> later on.  Define C<&fun_item> or @<&fun_store> as
C<undef> when they serve no purpose.

Once all items of a variable have been processed, the result (of the
calls to C<&fun_items>, or of recursive traversals of subvariables)
are passed to C<&fun_collect>.  C<&fun_collect> receives three
arguments:

  ($var,         -- the variable being traversed
   $parent_cond, -- the Condition inherited from parent
                    variables during recursion
   @condlist)    -- a list of [$cond, @results] pairs
                    where each $cond appear only once, and @result
                    are all the results for this condition.

Typically you should do C<$cond->merge ($parent_cond)> to recompute
the C<$full_cond> associated to C<@result>.  C<&fun_collect> may
return a list of items, that will be used as the result of
C<Automake::Variable::traverse_recursively> (the top-level, or its
recursive calls).

=cut

# Contains a stack of 'from' and 'to' parts of variable
# substitutions currently in force.
my @_substfroms;
my @_substtos;
sub traverse_recursively ($&&;%)
{
  ++$_traversal;
  @_substfroms = ();
  @_substtos = ();
  my ($var, $fun_item, $fun_collect, %options) = @_;
  my $cond_filter = $options{'cond_filter'};
  my $inner_expand = $options{'inner_expand'};
  my $skip_ac_subst = $options{'skip_ac_subst'};
  return $var->_do_recursive_traversal ($var,
					$fun_item, $fun_collect,
					$cond_filter, TRUE, $inner_expand,
					$skip_ac_subst)
}

# The guts of Automake::Variable::traverse_recursively.
sub _do_recursive_traversal ($$&&$$$$)
{
  my ($var, $parent, $fun_item, $fun_collect, $cond_filter, $parent_cond,
      $inner_expand, $skip_ac_subst) = @_;

  $var->set_seen;

  if ($var->{'scanned'} == $_traversal)
    {
      err_var $var, "variable '" . $var->name() . "' recursively defined";
      return ();
    }
  $var->{'scanned'} = $_traversal;

  my @allresults = ();
  my $cond_once = 0;
  foreach my $cond ($var->conditions->conds)
    {
      if (ref $cond_filter)
	{
	  # Ignore conditions that don't match $cond_filter.
	  next if ! $cond->true_when ($cond_filter);
	  # If we found out several definitions of $var
	  # match $cond_filter then we are in trouble.
	  # Tell the user we don't support this.
	  $var->check_defined_unconditionally ($parent, $parent_cond)
	    if $cond_once;
	  $cond_once = 1;
	}
      my @result = ();
      my $full_cond = $cond->merge ($parent_cond);

      my @to_process = $var->value_as_list ($cond, $parent, $parent_cond);
      while (@to_process)
	{
	  my $val = shift @to_process;
	  # If $val is a variable (i.e. ${foo} or $(bar), not a filename),
	  # handle the sub variable recursively.
	  # (Backslashes before '}' and ')' within brackets are here to
	  # please Emacs's indentation.)
	  if ($val =~ /^\$\{([^\}]*)\}$/ || $val =~ /^\$\(([^\)]*)\)$/)
	    {
	      my $subvarname = $1;

	      # If the user uses a losing variable name, just ignore it.
	      # This isn't ideal, but people have requested it.
	      next if ($subvarname =~ /\@.*\@/);

	      # See if the variable is actually a substitution reference
	      my ($from, $to);
              # This handles substitution references like ${foo:.a=.b}.
	      if ($subvarname =~ /^([^:]*):([^=]*)=(.*)$/o)
		{
		  $subvarname = $1;
		  $to = $3;
		  $from = quotemeta $2;
		}

	      my $subvar = var ($subvarname);
	      # Don't recurse into undefined variables.
	      next unless $subvar;

	      push @_substfroms, $from;
	      push @_substtos, $to;

	      my @res = $subvar->_do_recursive_traversal ($parent,
							  $fun_item,
							  $fun_collect,
							  $cond_filter,
							  $full_cond,
							  $inner_expand,
							  $skip_ac_subst);
	      push (@result, @res);

	      pop @_substfroms;
	      pop @_substtos;

	      next;
	    }
	  # Try to expand variable references inside filenames such as
	  # '$(NAME).txt'.  We do not handle ':.foo=.bar'
	  # substitutions, but it would make little sense to use this
	  # here anyway.
	  elsif ($inner_expand
		 && ($val =~ /\$\{([^\}]*)\}/ || $val =~ /\$\(([^\)]*)\)/))
	    {
	      my $subvarname = $1;
	      my $subvar = var $subvarname;
	      if ($subvar)
		{
		  # Replace the reference by its value, and reschedule
		  # for expansion.
		  foreach my $c ($subvar->conditions->conds)
		    {
		      if (ref $cond_filter)
			{
			  # Ignore conditions that don't match $cond_filter.
			  next if ! $c->true_when ($cond_filter);
			  # If we found out several definitions of $var
			  # match $cond_filter then we are in trouble.
			  # Tell the user we don't support this.
			  $subvar->check_defined_unconditionally ($var,
								  $full_cond)
			    if $cond_once;
			  $cond_once = 1;
			}
		      my $subval = $subvar->rdef ($c)->value;
		      $val =~ s/\$\{$subvarname\}/$subval/g;
		      $val =~ s/\$\($subvarname\)/$subval/g;
		      unshift @to_process, split (' ', $val);
		    }
		  next;
		}
	      # We do not know any variable with this name.  Fall through
	      # to filename processing.
	    }
	  elsif ($skip_ac_subst && $val =~ /^\@.+\@$/)
	    {
	      next;
	    }

	  if ($fun_item) # $var is a filename we must process
	    {
	      my $substnum=$#_substfroms;
	      while ($substnum >= 0)
		{
		  $val =~ s/$_substfroms[$substnum]$/$_substtos[$substnum]/
		    if defined $_substfroms[$substnum];
		  $substnum -= 1;
		}

	      # Make sure you update the doc of
	      # Automake::Variable::traverse_recursively
	      # if you change the prototype of &fun_item.
	      my @transformed = &$fun_item ($var, $val, $cond, $full_cond);
	      push (@result, @transformed);
	    }
	}
      push (@allresults, [$cond, @result]) if @result;
    }

  # We only care about _recursive_ variable definitions.  The user
  # is free to use the same variable several times in the same definition.
  $var->{'scanned'} = -1;

  return ()
    unless $fun_collect;
  # Make sure you update the doc of Automake::Variable::traverse_recursively
  # if you change the prototype of &fun_collect.
  return &$fun_collect ($var, $parent_cond, @allresults);
}

# _hash_varname ($VAR)
# --------------------
# Compute the key associated $VAR in %_gen_varname.
# See _gen_varname() below.
sub _hash_varname ($)
{
  my ($var) = @_;
  my $key = '';
  foreach my $cond ($var->conditions->conds)
    {
      my @values = $var->value_as_list ($cond);
      $key .= "($cond)@values";
    }
  return $key;
}

# _hash_values (@VALUES)
# ----------------------
# Hash @VALUES for %_gen_varname.  @VALUES should be a list
# of pairs: ([$cond, @values], [$cond, @values], ...).
# See _gen_varname() below.
sub _hash_values (@)
{
  my $key = '';
  foreach my $pair (@_)
    {
      my ($cond, @values) = @$pair;
      $key .= "($cond)@values";
    }
  return $key;
}
# ($VARNAME, $GENERATED)
# _gen_varname ($BASE, @DEFINITIONS)
# ----------------------------------
# Return a variable name starting with $BASE, that will be
# used to store definitions @DEFINITIONS.
# @DEFINITIONS is a list of pair [$COND, @OBJECTS].
#
# If we already have a $BASE-variable containing @DEFINITIONS, reuse
# it and set $GENERATED to 0.  Otherwise construct a new name and set
# $GENERATED to 1.
#
# This way, we avoid combinatorial explosion of the generated
# variables.  Especially, in a Makefile such as:
#
# | if FOO1
# | A1=1
# | endif
# |
# | if FOO2
# | A2=2
# | endif
# |
# | ...
# |
# | if FOON
# | AN=N
# | endif
# |
# | B=$(A1) $(A2) ... $(AN)
# |
# | c_SOURCES=$(B)
# | d_SOURCES=$(B)
#
# The generated c_OBJECTS and d_OBJECTS will share the same variable
# definitions.
#
# This setup can be the case of a testsuite containing lots (>100) of
# small C programs, all testing the same set of source files.
sub _gen_varname ($@)
{
  my $base = shift;
  my $key = _hash_values @_;

  return ($_gen_varname{$base}{$key}, 0)
    if exists $_gen_varname{$base}{$key};

  my $num = 1 + ($_gen_varname_n{$base} || 0);
  $_gen_varname_n{$base} = $num;
  my $name = "${base}_${num}";
  $_gen_varname{$base}{$key} = $name;

  return ($name, 1);
}

=item C<$resvar = transform_variable_recursively ($var, $resvar, $base, $nodefine, $where, &fun_item, [%options])>

=item C<$resvar = $var-E<gt>transform_variable_recursively ($resvar, $base, $nodefine, $where, &fun_item, [%options])>

Traverse C<$var> recursively, and create a C<$resvar> variable in
which each filename in C<$var> have been transformed using
C<&fun_item>.  (C<$var> may be a variable name in the first syntax.
It must be an C<Automake::Variable> otherwise.)

Helper variables (corresponding to sub-variables of C<$var>) are
created as needed, using C<$base> as prefix.

Arguments are:
  $var       source variable to traverse
  $resvar    resulting variable to define
  $base      prefix to use when naming subvariables of $resvar
  $nodefine  if true, traverse $var but do not define any variable
             (this assumes &fun_item has some useful side-effect)
  $where     context into which variable definitions are done
  &fun_item  a transformation function -- see the documentation
             of &fun_item in Automake::Variable::traverse_recursively.

This returns the string C<"\$($RESVAR)">.

C<%options> is a list of options to pass to
C<Variable::traverse_recursively> (see this method).

=cut

sub transform_variable_recursively ($$$$$&;%)
{
  my ($var, $resvar, $base, $nodefine, $where, $fun_item, %options) = @_;

  $var = ref $var ? $var : rvar $var;

  my $res = $var->traverse_recursively
    ($fun_item,
     # The code that defines the variable holding the result
     # of the recursive transformation of a subvariable.
     sub {
       my ($subvar, $parent_cond, @allresults) = @_;
       # If no definition is required, return anything: the result is
       # not expected to be used, only the side effect of $fun_item
       # should matter.
       return 'report-me' if $nodefine;
       # Cache $subvar, so that we reuse it if @allresults is the same.
       my $key = _hash_varname $subvar;
       $_gen_varname{$base}{$key} = $subvar->name;

       # Find a name for the variable, unless this is the top-variable
       # for which we want to use $resvar.
       my ($varname, $generated) =
	 ($var != $subvar) ? _gen_varname ($base, @allresults) : ($resvar, 1);

       # Define the variable if we are not reusing a previously
       # defined variable.  At the top-level, we can also avoid redefining
       # the variable if it already contains the same values.
       if ($generated
	   && !($varname eq $var->name && $key eq _hash_values @allresults))
	 {
	   # If the new variable is the source variable, we assume
	   # we are trying to override a user variable.  Delete
	   # the old variable first.
	   variable_delete ($varname) if $varname eq $var->name;
	   # Define an empty variable in condition TRUE if there is no
	   # result.
	   @allresults = ([TRUE, '']) unless @allresults;
	   # Define the rewritten variable in all conditions not
	   # already covered by user definitions.
	   foreach my $pair (@allresults)
	     {
	       my ($cond, @result) = @$pair;
	       my $var = var $varname;
	       my @conds = ($var
			    ? $var->not_always_defined_in_cond ($cond)->conds
			    : $cond);

	       foreach (@conds)
		 {
		   define ($varname, VAR_AUTOMAKE, '', $_, "@result",
			   '', $where, VAR_PRETTY);
		 }
	     }
	 }
       set_seen $varname;
       return "\$($varname)";
     },
     %options);
  return $res;
}


=back

=head1 SEE ALSO

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

=cut

1;
kc3-lang/automake/lib/Automake/Variable.pm

Commit

kc3-lang/automake /lib/Automake/Variable.pm
