Current File : //usr/share/automake-1.16/Automake/VarDef.pm
# Copyright (C) 2003-2018 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::VarDef;
use 5.006;
use strict;
use Carp;
use Automake::ChannelDefs;
use Automake::ItemDef;
require Exporter;
use vars '@ISA', '@EXPORT';
@ISA = qw/Automake::ItemDef Exporter/;
@EXPORT = qw (&VAR_AUTOMAKE &VAR_CONFIGURE &VAR_MAKEFILE
&VAR_ASIS &VAR_PRETTY &VAR_SILENT &VAR_SORTED);
=head1 NAME
Automake::VarDef - a class for variable definitions
=head1 SYNOPSIS
use Automake::VarDef;
use Automake::Location;
# Create a VarDef for a definition such as
# | # any comment
# | foo = bar # more comment
# in Makefile.am
my $loc = new Automake::Location 'Makefile.am:2';
my $def = new Automake::VarDef ('foo', 'bar # more comment',
'# any comment',
$loc, '', VAR_MAKEFILE, VAR_ASIS);
# Appending to a definition.
$def->append ('value to append', 'comment to append');
# Accessors.
my $value = $def->value; # with trailing '#' comments and
# continuation ("\\\n") omitted.
my $value = $def->raw_value; # the real value, as passed to new().
my $comment = $def->comment;
my $location = $def->location;
my $type = $def->type;
my $owner = $def->owner;
my $pretty = $def->pretty;
# Changing owner.
$def->set_owner (VAR_CONFIGURE,
new Automake::Location 'configure.ac:15');
# Marking examined definitions.
$def->set_seen;
my $seen_p = $def->seen;
# Printing a variable for debugging.
print STDERR $def->dump;
=head1 DESCRIPTION
This class gathers data related to one Makefile-variable definition.
=head2 Constants
=over 4
=item C<VAR_AUTOMAKE>, C<VAR_CONFIGURE>, C<VAR_MAKEFILE>
Possible owners for variables. A variable can be defined
by Automake, in F<configure.ac> (using C<AC_SUBST>), or in
the user's F<Makefile.am>.
=cut
# Defined so that the owner of a variable can only be increased (e.g
# Automake should not override a configure or Makefile variable).
use constant VAR_AUTOMAKE => 0; # Variable defined by Automake.
use constant VAR_CONFIGURE => 1;# Variable defined in configure.ac.
use constant VAR_MAKEFILE => 2; # Variable defined in Makefile.am.
=item C<VAR_ASIS>, C<VAR_PRETTY>, C<VAR_SILENT>, C<VAR_SORTED>
Possible print styles. C<VAR_ASIS> variables should be output as-is.
C<VAR_PRETTY> variables are wrapped on multiple lines if they cannot
fit on one. C<VAR_SILENT> variables are not output at all. Finally,
C<VAR_SORTED> variables should be sorted and then handled as
C<VAR_PRETTY> variables.
C<VAR_SILENT> variables can also be overridden silently (unlike the
other kinds of variables whose overriding may sometimes produce
warnings).
=cut
# Possible values for pretty.
use constant VAR_ASIS => 0; # Output as-is.
use constant VAR_PRETTY => 1; # Pretty printed on output.
use constant VAR_SILENT => 2; # Not output. (Can also be
# overridden silently.)
use constant VAR_SORTED => 3; # Sorted and pretty-printed.
=back
=head2 Methods
C<VarDef> defines the following methods in addition to those inherited
from L<Automake::ItemDef>.
=over 4
=item C<my $def = new Automake::VarDef ($varname, $value, $comment, $location, $type, $owner, $pretty)>
Create a new Makefile-variable definition. C<$varname> is the name of
the variable being defined and C<$value> its value.
C<$comment> is any comment preceding the definition. (Because
Automake reorders variable definitions in the output, it also tries to
carry comments around.)
C<$location> is the place where the definition occurred, it should be
an instance of L<Automake::Location>.
C<$type> should be C<''> for definitions made with C<=>, and C<':'>
for those made with C<:=>.
C<$owner> specifies who owns the variables, it can be one of
C<VAR_AUTOMAKE>, C<VAR_CONFIGURE>, or C<VAR_MAKEFILE> (see these
definitions).
Finally, C<$pretty> tells how the variable should be output, and can
be one of C<VAR_ASIS>, C<VAR_PRETTY>, or C<VAR_SILENT>, or
C<VAR_SORTED> (see these definitions).
=cut
sub new ($$$$$$$$)
{
my ($class, $var, $value, $comment, $location, $type, $owner, $pretty) = @_;
# A user variable must be set by either '=' or ':=', and later
# promoted to '+='.
if ($owner != VAR_AUTOMAKE && $type eq '+')
{
error $location, "$var must be set with '=' before using '+='";
}
my $self = Automake::ItemDef::new ($class, $comment, $location, $owner);
$self->{'value'} = $value;
$self->{'type'} = $type;
$self->{'pretty'} = $pretty;
$self->{'seen'} = 0;
return $self;
}
=item C<$def-E<gt>append ($value, $comment)>
Append C<$value> and <$comment> to the existing value and comment of
C<$def>. This is normally called on C<+=> definitions.
=cut
sub append ($$$)
{
my ($self, $value, $comment) = @_;
$self->{'comment'} .= $comment;
my $val = $self->{'value'};
# Strip comments from augmented variables. This is so that
# VAR = foo # com
# VAR += bar
# does not become
# VAR = foo # com bar
# Furthermore keeping '#' would not be portable if the variable is
# output on multiple lines.
$val =~ s/ ?#.*//;
# Insert a separator, if required.
$val .= ' ' if $val;
$self->{'value'} = $val . $value;
# Turn ASIS appended variables into PRETTY variables. This is to
# cope with 'make' implementation that cannot read very long lines.
$self->{'pretty'} = VAR_PRETTY if $self->{'pretty'} == VAR_ASIS;
}
=item C<$def-E<gt>value>
=item C<$def-E<gt>raw_value>
=item C<$def-E<gt>type>
=item C<$def-E<gt>pretty>
Accessors to the various constituents of a C<VarDef>. See the
documentation of C<new>'s arguments for a description of these.
=cut
sub value ($)
{
my ($self) = @_;
my $val = $self->raw_value;
# Strip anything past '#'. '#' characters cannot be escaped
# in Makefiles, so we don't have to be smart.
$val =~ s/#.*$//s;
# Strip backslashes.
$val =~ s/\\$/ /mg;
return $val;
}
sub raw_value ($)
{
my ($self) = @_;
return $self->{'value'};
}
sub type ($)
{
my ($self) = @_;
return $self->{'type'};
}
sub pretty ($)
{
my ($self) = @_;
return $self->{'pretty'};
}
=item C<$def-E<gt>set_owner ($owner, $location)>
Change the owner of a definition. This usually happens because
the user used C<+=> on an Automake variable, so (s)he now owns
the content. C<$location> should be an instance of L<Automake::Location>
indicating where the change took place.
=cut
sub set_owner ($$$)
{
my ($self, $owner, $location) = @_;
# We always adjust the location when the owner changes (even for
# '+=' statements). The risk otherwise is to warn about
# a VAR_MAKEFILE variable and locate it in configure.ac...
$self->{'owner'} = $owner;
$self->{'location'} = $location;
}
=item C<$def-E<gt>set_seen>
=item C<$bool = $def-E<gt>seen>
These function allows Automake to mark (C<set_seen>) variable that
it has examined in some way, and latter check (using C<seen>) for
unused variables. Unused variables usually indicate typos.
=cut
sub set_seen ($)
{
my ($self) = @_;
$self->{'seen'} = 1;
}
sub seen ($)
{
my ($self) = @_;
return $self->{'seen'};
}
=item C<$str = $def-E<gt>dump>
Format the contents of C<$def> as a human-readable string,
for debugging.
=cut
sub dump ($)
{
my ($self) = @_;
my $owner = $self->owner;
if ($owner == VAR_AUTOMAKE)
{
$owner = 'Automake';
}
elsif ($owner == VAR_CONFIGURE)
{
$owner = 'Configure';
}
elsif ($owner == VAR_MAKEFILE)
{
$owner = 'Makefile';
}
else
{
prog_error ("unexpected owner");
}
my $where = $self->location->dump;
my $comment = $self->comment;
my $value = $self->raw_value;
my $type = $self->type;
return "{
type: $type=
where: $where comment: $comment
value: $value
owner: $owner
}\n";
}
=back
=head1 SEE ALSO
L<Automake::Variable>, L<Automake::ItemDef>.
=cut
1;
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