View file File name : Item.pm Content :# 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::Item; use 5.006; use strict; use Carp; use Automake::ChannelDefs; use Automake::DisjConditions; =head1 NAME Automake::Item - base class for Automake::Variable and Automake::Rule =head1 DESCRIPTION =head2 Methods =over 4 =item C<new Automake::Item $name> Create and return an empty Item called C<$name>. =cut sub new ($$) { my ($class, $name) = @_; my $self = { name => $name, defs => {}, conds => {}, }; bless $self, $class; return $self; } =item C<$item-E<gt>name> Return the name of C<$item>. =cut sub name ($) { my ($self) = @_; return $self->{'name'}; } =item C<$item-E<gt>def ($cond)> Return the definition for this item in condition C<$cond>, if it exists. Return 0 otherwise. =cut sub def ($$) { # This method is called very often, so keep it small and fast. We # don't mind the extra undefined items introduced by lookup failure; # avoiding this with 'exists' means doing two hash lookup on # success, and proved worse on benchmark. my $def = $_[0]->{'defs'}{$_[1]}; return defined $def && $def; } =item C<$item-E<gt>rdef ($cond)> Return the definition for this item in condition C<$cond>. Abort with an internal error if the item was not defined under this condition. The I<r> in front of C<def> stands for I<required>. One should call C<rdef> to assert the conditional definition's existence. =cut sub rdef ($$) { my ($self, $cond) = @_; my $d = $self->def ($cond); prog_error ("undefined condition '" . $cond->human . "' for '" . $self->name . "'\n" . $self->dump) unless $d; return $d; } =item C<$item-E<gt>set ($cond, $def)> Add a new definition to an existing item. =cut sub set ($$$) { my ($self, $cond, $def) = @_; $self->{'defs'}{$cond} = $def; $self->{'conds'}{$cond} = $cond; } =item C<$var-E<gt>conditions> Return an L<Automake::DisjConditions> describing the conditions that that an item is defined in. These are all the conditions for which is would be safe to call C<rdef>. =cut sub conditions ($) { my ($self) = @_; prog_error ("self is not a reference") unless ref $self; return new Automake::DisjConditions (values %{$self->{'conds'}}); } =item C<@missing_conds = $var-E<gt>not_always_defined_in_cond ($cond)> Check whether C<$var> is always defined for condition C<$cond>. Return a list of conditions where the definition is missing. For instance, given if COND1 if COND2 A = foo D = d1 else A = bar D = d2 endif else D = d3 endif if COND3 A = baz B = mumble endif C = mumble we should have (we display result as conditional strings in this illustration, but we really return DisjConditions objects): var ('A')->not_always_defined_in_cond ('COND1_TRUE COND2_TRUE') => () var ('A')->not_always_defined_in_cond ('COND1_TRUE') => () var ('A')->not_always_defined_in_cond ('TRUE') => ("COND1_FALSE COND3_FALSE") var ('B')->not_always_defined_in_cond ('COND1_TRUE') => ("COND1_TRUE COND3_FALSE") var ('C')->not_always_defined_in_cond ('COND1_TRUE') => () var ('D')->not_always_defined_in_cond ('TRUE') => () var ('Z')->not_always_defined_in_cond ('TRUE') => ("TRUE") =cut sub not_always_defined_in_cond ($$) { my ($self, $cond) = @_; # Compute the subconditions where $var isn't defined. return $self->conditions ->sub_conditions ($cond) ->invert ->multiply ($cond); } 1;