1 files changed, 150 insertions, 0 deletions
diff --git a/lib/Automake/CondStack.pm b/lib/Automake/CondStack.pm
new file mode 100644
index 000000000..5d5260719
--- /dev/null
+++ b/lib/Automake/CondStack.pm
@@ -0,0 +1,150 @@
+# Copyright (C) 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 3 of the License, 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 <http://www.gnu.org/licenses/>.
+
+package Automake::CondStack;
+
+use 5.006;
+use strict;
+
+use Exporter;
+use Automake::Condition qw (TRUE FALSE);
+use Automake::Global;
+use Automake::Channels;
+use Automake::ChannelDefs;
+
+use vars qw (@ISA @EXPORT);
+
+@ISA = qw (Exporter);
+@EXPORT = qw (cond_stack_if cond_stack_else cond_stack_endif);
+
+my %_am_macro_for_cond =
+  (
+   AMDEP => "one of the compiler tests\n"
+   . "    AC_PROG_CC, AC_PROG_CXX, AC_PROG_OBJC, AC_PROG_OBJCXX,\n"
+   . "    AM_PROG_AS, AM_PROG_GCJ, AM_PROG_UPC",
+   am__fastdepCC => 'AC_PROG_CC',
+   am__fastdepCCAS => 'AM_PROG_AS',
+   am__fastdepCXX => 'AC_PROG_CXX',
+   am__fastdepGCJ => 'AM_PROG_GCJ',
+   am__fastdepOBJC => 'AC_PROG_OBJC',
+   am__fastdepOBJCXX => 'AC_PROG_OBJCXX',
+   am__fastdepUPC => 'AM_PROG_UPC'
+  );
+
+
+# $STRING
+# _make_conditional_string ($NEGATE, $COND)
+# ----------------------------------------
+sub _make_conditional_string
+{
+  my ($negate, $cond) = @_;
+  $cond = "${cond}_TRUE"
+    unless $cond =~ /^TRUE|FALSE$/;
+  $cond = Automake::Condition::conditional_negate ($cond)
+    if $negate;
+  return $cond;
+}
+
+
+# $COND
+# cond_stack_if ($NEGATE, $COND, $WHERE)
+# --------------------------------------
+sub cond_stack_if
+{
+  my ($negate, $cond, $where) = @_;
+
+  if (! $configure_cond{$cond} && $cond !~ /^TRUE|FALSE$/)
+    {
+      my $text = "$cond does not appear in AM_CONDITIONAL";
+      my $scope = US_LOCAL;
+      if (exists $_am_macro_for_cond{$cond})
+	{
+	  my $mac = $_am_macro_for_cond{$cond};
+	  $text .= "\n  The usual way to define '$cond' is to add ";
+	  $text .= ($mac =~ / /) ? $mac : "'$mac'";
+	  $text .= "\n  to '$configure_ac' and run 'aclocal' and 'autoconf' again";
+	  # These warnings appear in Automake files (depend2.am),
+	  # so there is no need to display them more than once:
+	  $scope = US_GLOBAL;
+	}
+      error $where, $text, uniq_scope => $scope;
+    }
+
+  push (@cond_stack, _make_conditional_string ($negate, $cond));
+
+  return new Automake::Condition (@cond_stack);
+}
+
+
+# $COND
+# cond_stack_else ($NEGATE, $COND, $WHERE)
+# ----------------------------------------
+sub cond_stack_else
+{
+  my ($negate, $cond, $where) = @_;
+
+  if (! @cond_stack)
+    {
+      error $where, "else without if";
+      return FALSE;
+    }
+
+  $cond_stack[$#cond_stack] =
+    Automake::Condition::conditional_negate ($cond_stack[$#cond_stack]);
+
+  # If $COND is given, check against it.
+  if (defined $cond)
+    {
+      $cond = _make_conditional_string ($negate, $cond);
+
+      error ($where, "else reminder ($negate$cond) incompatible with "
+	     . "current conditional: $cond_stack[$#cond_stack]")
+	if $cond_stack[$#cond_stack] ne $cond;
+    }
+
+  return new Automake::Condition (@cond_stack);
+}
+
+
+# $COND
+# cond_stack_endif ($NEGATE, $COND, $WHERE)
+# -----------------------------------------
+sub cond_stack_endif
+{
+  my ($negate, $cond, $where) = @_;
+  my $old_cond;
+
+  if (! @cond_stack)
+    {
+      error $where, "endif without if";
+      return TRUE;
+    }
+
+  # If $COND is given, check against it.
+  if (defined $cond)
+    {
+      $cond = _make_conditional_string ($negate, $cond);
+
+      error ($where, "endif reminder ($negate$cond) incompatible with "
+	     . "current conditional: $cond_stack[$#cond_stack]")
+	if $cond_stack[$#cond_stack] ne $cond;
+    }
+
+  pop @cond_stack;
+
+  return new Automake::Condition (@cond_stack);
+}
+
+1;