Linux build: Use sysroot when calculating dependencies

third_party/dpkg-dev/scripts/Dpkg/IPC.pm

+# Copyright © 2008-2009 Raphaël Hertzog <hertzog@debian.org>
+# Copyright © 2008 Frank Lichtenheld <djpig@debian.org>
+#
+# 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 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 <https://www.gnu.org/licenses/>.
+
+package Dpkg::IPC;
+
+use strict;
+use warnings;
+
+our $VERSION = '1.00';
+
+use Dpkg::ErrorHandling;
+use Dpkg::Gettext;
+
+use Carp;
+use Exporter qw(import);
+our @EXPORT = qw(spawn wait_child);
+
+=encoding utf8
+
+=head1 NAME
+
+Dpkg::IPC - helper functions for IPC
+
+=head1 DESCRIPTION
+
+Dpkg::IPC offers helper functions to allow you to execute
+other programs in an easy, yet flexible way, while hiding
+all the gory details of IPC (Inter-Process Communication)
+from you.
+
+=head1 METHODS
+
+=over 4
+
+=item spawn
+
+Creates a child process and executes another program in it.
+The arguments are interpreted as a hash of options, specifying
+how to handle the in and output of the program to execute.
+Returns the pid of the child process (unless the wait_child
+option was given).
+
+Any error will cause the function to exit with one of the
+Dpkg::ErrorHandling functions.
+
+Options:
+
+=over 4
+
+=item exec
+
+Can be either a scalar, i.e. the name of the program to be
+executed, or an array reference, i.e. the name of the program
+plus additional arguments. Note that the program will never be
+executed via the shell, so you can't specify additional arguments
+in the scalar string and you can't use any shell facilities like
+globbing.
+
+Mandatory Option.
+
+=item from_file, to_file, error_to_file
+
+Filename as scalar. Standard input/output/error of the
+child process will be redirected to the file specified.
+
+=item from_handle, to_handle, error_to_handle
+
+Filehandle. Standard input/output/error of the child process will be
+dup'ed from the handle.
+
+=item from_pipe, to_pipe, error_to_pipe
+
+Scalar reference or object based on IO::Handle. A pipe will be opened for
+each of the two options and either the reading (C<to_pipe> and
+C<error_to_pipe>) or the writing end (C<from_pipe>) will be returned in
+the referenced scalar. Standard input/output/error of the child process
+will be dup'ed to the other ends of the pipes.
+
+=item from_string, to_string, error_to_string
+
+Scalar reference. Standard input/output/error of the child
+process will be redirected to the string given as reference. Note
+that it wouldn't be strictly necessary to use a scalar reference
+for C<from_string>, as the string is not modified in any way. This was
+chosen only for reasons of symmetry with C<to_string> and
+C<error_to_string>. C<to_string> and C<error_to_string> imply the
+C<wait_child> option.
+
+=item wait_child
+
+Scalar. If containing a true value, wait_child() will be called before
+returning. The return value of spawn() will be a true value, not the pid.
+
+=item nocheck
+
+Scalar. Option of the wait_child() call.
+
+=item timeout
+
+Scalar. Option of the wait_child() call.
+
+=item chdir
+
+Scalar. The child process will chdir in the indicated directory before
+calling exec.
+
+=item env
+
+Hash reference. The child process will populate %ENV with the items of the
+hash before calling exec. This allows exporting environment variables.
+
+=item delete_env
+
+Array reference. The child process will remove all environment variables
+listed in the array before calling exec.
+
+=back
+
+=cut
+
+sub _sanity_check_opts {
+    my (%opts) = @_;
+
+    croak 'exec parameter is mandatory in spawn()'
+        unless $opts{exec};
+
+    my $to = my $error_to = my $from = 0;
+    foreach (qw(file handle string pipe)) {
+        $to++ if $opts{"to_$_"};
+        $error_to++ if $opts{"error_to_$_"};
+        $from++ if $opts{"from_$_"};
+    }
+    croak 'not more than one of to_* parameters is allowed'
+        if $to > 1;
+    croak 'not more than one of error_to_* parameters is allowed'
+        if $error_to > 1;
+    croak 'not more than one of from_* parameters is allowed'
+        if $from > 1;
+
+    foreach (qw(to_string error_to_string from_string)) {
+        if (exists $opts{$_} and
+            (not ref($opts{$_}) or ref($opts{$_}) ne 'SCALAR')) {
+            croak "parameter $_ must be a scalar reference";
+        }
+    }
+
+    foreach (qw(to_pipe error_to_pipe from_pipe)) {
+        if (exists $opts{$_} and
+            (not ref($opts{$_}) or (ref($opts{$_}) ne 'SCALAR' and
+                                 not $opts{$_}->isa('IO::Handle')))) {
+            croak "parameter $_ must be a scalar reference or " .
+                  'an IO::Handle object';
+        }
+    }
+
+    if (exists $opts{timeout} and defined($opts{timeout}) and
+        $opts{timeout} !~ /^\d+$/) {
+        croak 'parameter timeout must be an integer';
+    }
+
+    if (exists $opts{env} and ref($opts{env}) ne 'HASH') {
+        croak 'parameter env must be a hash reference';
+    }
+
+    if (exists $opts{delete_env} and ref($opts{delete_env}) ne 'ARRAY') {
+        croak 'parameter delete_env must be an array reference';
+    }
+
+    return %opts;
+}
+
+sub spawn {
+    my (%opts) = _sanity_check_opts(@_);
+    $opts{close_in_child} ||= [];
+    my @prog;
+    if (ref($opts{exec}) =~ /ARRAY/) {
+        push @prog, @{$opts{exec}};
+    } elsif (not ref($opts{exec})) {
+        push @prog, $opts{exec};
+    } else {
+        croak 'invalid exec parameter in spawn()';
+    }
+    my ($from_string_pipe, $to_string_pipe, $error_to_string_pipe);
+    if ($opts{to_string}) {
+        $opts{to_pipe} = \$to_string_pipe;
+        $opts{wait_child} = 1;
+    }
+    if ($opts{error_to_string}) {
+        $opts{error_to_pipe} = \$error_to_string_pipe;
+        $opts{wait_child} = 1;
+    }
+    if ($opts{from_string}) {
+        $opts{from_pipe} = \$from_string_pipe;
+    }
+    # Create pipes if needed
+    my ($input_pipe, $output_pipe, $error_pipe);
+    if ($opts{from_pipe}) {
+        pipe($opts{from_handle}, $input_pipe)
+            or syserr(_g('pipe for %s'), "@prog");
+        ${$opts{from_pipe}} = $input_pipe;
+        push @{$opts{close_in_child}}, $input_pipe;
+    }
+    if ($opts{to_pipe}) {
+        pipe($output_pipe, $opts{to_handle})
+            or syserr(_g('pipe for %s'), "@prog");
+        ${$opts{to_pipe}} = $output_pipe;
+        push @{$opts{close_in_child}}, $output_pipe;
+    }
+    if ($opts{error_to_pipe}) {
+        pipe($error_pipe, $opts{error_to_handle})
+            or syserr(_g('pipe for %s'), "@prog");
+        ${$opts{error_to_pipe}} = $error_pipe;
+        push @{$opts{close_in_child}}, $error_pipe;
+    }
+    # Fork and exec
+    my $pid = fork();
+    syserr(_g('cannot fork for %s'), "@prog") unless defined $pid;
+    if (not $pid) {
+        # Define environment variables
+        if ($opts{env}) {
+            foreach (keys %{$opts{env}}) {
+                $ENV{$_} = $opts{env}{$_};
+            }
+        }
+        if ($opts{delete_env}) {
+            delete $ENV{$_} foreach (@{$opts{delete_env}});
+        }
+        # Change the current directory
+        if ($opts{chdir}) {
+            chdir($opts{chdir}) or syserr(_g('chdir to %s'), $opts{chdir});
+        }
+        # Redirect STDIN if needed
+        if ($opts{from_file}) {
+            open(STDIN, '<', $opts{from_file})
+                or syserr(_g('cannot open %s'), $opts{from_file});
+        } elsif ($opts{from_handle}) {
+            open(STDIN, '<&', $opts{from_handle})
+                or syserr(_g('reopen stdin'));
+            close($opts{from_handle}); # has been duped, can be closed
+        }
+        # Redirect STDOUT if needed
+        if ($opts{to_file}) {
+            open(STDOUT, '>', $opts{to_file})
+                or syserr(_g('cannot write %s'), $opts{to_file});
+        } elsif ($opts{to_handle}) {
+            open(STDOUT, '>&', $opts{to_handle})
+                or syserr(_g('reopen stdout'));
+            close($opts{to_handle}); # has been duped, can be closed
+        }
+        # Redirect STDERR if needed
+        if ($opts{error_to_file}) {
+            open(STDERR, '>', $opts{error_to_file})
+                or syserr(_g('cannot write %s'), $opts{error_to_file});
+        } elsif ($opts{error_to_handle}) {
+            open(STDERR, '>&', $opts{error_to_handle})
+                or syserr(_g('reopen stdout'));
+            close($opts{error_to_handle}); # has been duped, can be closed
+        }
+        # Close some inherited filehandles
+        close($_) foreach (@{$opts{close_in_child}});
+        # Execute the program
+        exec({ $prog[0] } @prog) or syserr(_g('unable to execute %s'), "@prog");
+    }
+    # Close handle that we can't use any more
+    close($opts{from_handle}) if exists $opts{from_handle};
+    close($opts{to_handle}) if exists $opts{to_handle};
+    close($opts{error_to_handle}) if exists $opts{error_to_handle};
+
+    if ($opts{from_string}) {
+        print { $from_string_pipe } ${$opts{from_string}};
+        close($from_string_pipe);
+    }
+    if ($opts{to_string}) {
+        local $/ = undef;
+        ${$opts{to_string}} = readline($to_string_pipe);
+    }
+    if ($opts{error_to_string}) {
+        local $/ = undef;
+        ${$opts{error_to_string}} = readline($error_to_string_pipe);
+    }
+    if ($opts{wait_child}) {
+        my $cmdline = "@prog";
+        if ($opts{env}) {
+            foreach (keys %{$opts{env}}) {
+                $cmdline = "$_=\"" . $opts{env}{$_} . "\" $cmdline";
+            }
+        }
+        wait_child($pid, nocheck => $opts{nocheck},
+                   timeout => $opts{timeout}, cmdline => $cmdline);
+        return 1;
+    }
+
+    return $pid;
+}
+
+
+=item wait_child
+
+Takes as first argument the pid of the process to wait for.
+Remaining arguments are taken as a hash of options. Returns
+nothing. Fails if the child has been ended by a signal or
+if it exited non-zero.
+
+Options:
+
+=over 4
+
+=item cmdline
+
+String to identify the child process in error messages.
+Defaults to "child process".
+
+=item nocheck
+
+If true do not check the return status of the child (and thus
+do not fail it it has been killed or if it exited with a
+non-zero return code).
+
+=item timeout
+
+Set a maximum time to wait for the process, after that fail
+with an error message.
+
+=back
+
+=cut
+
+sub wait_child {
+    my ($pid, %opts) = @_;
+    $opts{cmdline} ||= _g('child process');
+    croak 'no PID set, cannot wait end of process' unless $pid;
+    eval {
+        local $SIG{ALRM} = sub { die "alarm\n" };
+        alarm($opts{timeout}) if defined($opts{timeout});
+        $pid == waitpid($pid, 0) or syserr(_g('wait for %s'), $opts{cmdline});
+        alarm(0) if defined($opts{timeout});
+    };
+    if ($@) {
+        die $@ unless $@ eq "alarm\n";
+        error(ngettext("%s didn't complete in %d second",
+                       "%s didn't complete in %d seconds",
+                       $opts{timeout}),
+              $opts{cmdline}, $opts{timeout});
+    }
+    unless ($opts{nocheck}) {
+        subprocerr($opts{cmdline}) if $?;
+    }
+}
+
+1;
+__END__
+
+=back
+
+=head1 AUTHORS
+
+Written by Raphaël Hertzog <hertzog@debian.org> and
+Frank Lichtenheld <djpig@debian.org>.
+
+=head1 SEE ALSO
+
+Dpkg, Dpkg::ErrorHandling