release/src-rt-6.x.4708/toolchains/hndtools-arm-linux-2.6.36-uclibc-4.5.3/share/automake-1.11/Automake/Item.pm

   1 # Copyright (C) 2003, 2004  Free Software Foundation, Inc.
   2
   3 # This program is free software; you can redistribute it and/or modify
   4 # it under the terms of the GNU General Public License as published by
   5 # the Free Software Foundation; either version 2, or (at your option)
   6 # any later version.
   7
   8 # This program is distributed in the hope that it will be useful,
   9 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 # GNU General Public License for more details.
  12
  13 # You should have received a copy of the GNU General Public License
  14 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15
  16 package Automake::Item;
  17 use strict;
  18 use Carp;
  19
  20 use Automake::ChannelDefs;
  21 use Automake::DisjConditions;
  22
  23 =head1 NAME
  24
  25 Automake::Item - base class for Automake::Variable and Automake::Rule
  26
  27 =head1 DESCRIPTION
  28
  29 =head2 Methods
  30
  31 =over 4
  32
  33 =item C<new Automake::Item $name>
  34
  35 Create and return an empty Item called C<$name>.
  36
  37 =cut
  38
  39 sub new ($$)
  40 {
  41   my ($class, $name) = @_;
  42   my $self = {
  43     name => $name,
  44     defs => {},
  45     conds => {},
  46   };
  47   bless $self, $class;
  48   return $self;
  49 }
  50
  51 =item C<$item-E<gt>name>
  52
  53 Return the name of C<$item>.
  54
  55 =cut
  56
  57 sub name ($)
  58 {
  59   my ($self) = @_;
  60   return $self->{'name'};
  61 }
  62
  63 =item C<$item-E<gt>def ($cond)>
  64
  65 Return the definition for this item in condition C<$cond>, if it
  66 exists.  Return 0 otherwise.
  67
  68 =cut
  69
  70 sub def ($$)
  71 {
  72   # This method is called very often, so keep it small and fast.  We
  73   # don't mind the extra undefined items introduced by lookup failure;
  74   # avoiding this with `exists' means doing two hash lookup on
  75   # success, and proved worse on benchmark.
  76   my $def = $_[0]->{'defs'}{$_[1]};
  77   return defined $def && $def;
  78 }
  79
  80 =item C<$item-E<gt>rdef ($cond)>
  81
  82 Return the definition for this item in condition C<$cond>.  Abort with
  83 an internal error if the item was not defined under this condition.
  84
  85 The I<r> in front of C<def> stands for I<required>.  One
  86 should call C<rdef> to assert the conditional definition's existence.
  87
  88 =cut
  89
  90 sub rdef ($$)
  91 {
  92   my ($self, $cond) = @_;
  93   my $d = $self->def ($cond);
  94   prog_error ("undefined condition `" . $cond->human . "' for `"
  95               . $self->name . "'\n" . $self->dump)
  96     unless $d;
  97   return $d;
  98 }
  99
 100 =item C<$item-E<gt>set ($cond, $def)>
 101
 102 Add a new definition to an existing item.
 103
 104 =cut
 105
 106 sub set ($$$)
 107 {
 108   my ($self, $cond, $def) = @_;
 109   $self->{'defs'}{$cond} = $def;
 110   $self->{'conds'}{$cond} = $cond;
 111 }
 112
 113 =item C<$var-E<gt>conditions>
 114
 115 Return an L<Automake::DisjConditions> describing the conditions that
 116 that an item is defined in.
 117
 118 These are all the conditions for which is would be safe to call
 119 C<rdef>.
 120
 121 =cut
 122
 123 sub conditions ($)
 124 {
 125   my ($self) = @_;
 126   prog_error ("self is not a reference")
 127     unless ref $self;
 128   return new Automake::DisjConditions (values %{$self->{'conds'}});
 129 }
 130
 131 =item C<@missing_conds = $var-E<gt>not_always_defined_in_cond ($cond)>
 132
 133 Check whether C<$var> is always defined for condition C<$cond>.
 134 Return a list of conditions where the definition is missing.
 135
 136 For instance, given
 137
 138   if COND1
 139     if COND2
 140       A = foo
 141       D = d1
 142     else
 143       A = bar
 144       D = d2
 145     endif
 146   else
 147     D = d3
 148   endif
 149   if COND3
 150     A = baz
 151     B = mumble
 152   endif
 153   C = mumble
 154
 155 we should have (we display result as conditional strings in this
 156 illustration, but we really return DisjConditions objects):
 157
 158   var ('A')->not_always_defined_in_cond ('COND1_TRUE COND2_TRUE')
 159     => ()
 160   var ('A')->not_always_defined_in_cond ('COND1_TRUE')
 161     => ()
 162   var ('A')->not_always_defined_in_cond ('TRUE')
 163     => ("COND1_FALSE COND3_FALSE")
 164   var ('B')->not_always_defined_in_cond ('COND1_TRUE')
 165     => ("COND1_TRUE COND3_FALSE")
 166   var ('C')->not_always_defined_in_cond ('COND1_TRUE')
 167     => ()
 168   var ('D')->not_always_defined_in_cond ('TRUE')
 169     => ()
 170   var ('Z')->not_always_defined_in_cond ('TRUE')
 171     => ("TRUE")
 172
 173 =cut
 174
 175 sub not_always_defined_in_cond ($$)
 176 {
 177   my ($self, $cond) = @_;
 178
 179   # Compute the subconditions where $var isn't defined.
 180   return
 181     $self->conditions
 182       ->sub_conditions ($cond)
 183         ->invert
 184           ->multiply ($cond);
 185 }
 186
 187
 188 1;
 189
 190 ### Setup "GNU" style for perl-mode and cperl-mode.
 191 ## Local Variables:
 192 ## perl-indent-level: 2
 193 ## perl-continued-statement-offset: 2
 194 ## perl-continued-brace-offset: 0
 195 ## perl-brace-offset: 0
 196 ## perl-brace-imaginary-offset: 0
 197 ## perl-label-offset: -2
 198 ## cperl-indent-level: 2
 199 ## cperl-brace-offset: 0
 200 ## cperl-continued-brace-offset: 0
 201 ## cperl-label-offset: -2
 202 ## cperl-extra-newline-before-brace: t
 203 ## cperl-merge-trailing-else: nil
 204 ## cperl-continued-statement-offset: 2
 205 ## End: