path: root/t/pragma/sub_lval.t

print "1..46\n";

BEGIN {
    chdir 't' if -d 't';
    unshift @INC, '../lib';
}

sub a {use attrs 'lvalue'; my $a = 34; bless \$a}  # Return a temporary
sub b {use attrs 'lvalue'; shift}

my $out = a(b());		# Check that temporaries are allowed.
print "# `$out'\nnot " unless ref $out eq 'main'; # Not reached if error.
print "ok 1\n";

my @out = grep /main/, a(b()); # Check that temporaries are allowed.
print "# `@out'\nnot " unless @out==1; # Not reached if error.
print "ok 2\n";

my $in;

# Check that we can return localized values from subroutines:

sub in {use attrs 'lvalue'; $in = shift;}
sub neg {use attrs 'lvalue';  #(num_str) return num_str
    local $_ = shift;
    s/^\+/-/;
    $_;
}
in(neg("+2"));


print "# `$in'\nnot " unless $in eq '-2';
print "ok 3\n";

sub get_lex {use attrs 'lvalue'; $in}
sub get_st {use attrs 'lvalue'; $blah}
sub id {use attrs 'lvalue'; shift}
sub id1 {use attrs 'lvalue'; $_[0]}
sub inc {use attrs 'lvalue'; ++$_[0]}

$in = 5;
$blah = 3;

get_st = 7;

print "# `$blah' ne 7\nnot " unless $blah eq 7;
print "ok 4\n";

get_lex = 7;

print "# `$in' ne 7\nnot " unless $in eq 7;
print "ok 5\n";

++get_st;

print "# `$blah' ne 8\nnot " unless $blah eq 8;
print "ok 6\n";

++get_lex;

print "# `$in' ne 8\nnot " unless $in eq 8;
print "ok 7\n";

id(get_st) = 10;

print "# `$blah' ne 10\nnot " unless $blah eq 10;
print "ok 8\n";

id(get_lex) = 10;

print "# `$in' ne 10\nnot " unless $in eq 10;
print "ok 9\n";

++id(get_st);

print "# `$blah' ne 11\nnot " unless $blah eq 11;
print "ok 10\n";

++id(get_lex);

print "# `$in' ne 11\nnot " unless $in eq 11;
print "ok 11\n";

id1(get_st) = 20;

print "# `$blah' ne 20\nnot " unless $blah eq 20;
print "ok 12\n";

id1(get_lex) = 20;

print "# `$in' ne 20\nnot " unless $in eq 20;
print "ok 13\n";

++id1(get_st);

print "# `$blah' ne 21\nnot " unless $blah eq 21;
print "ok 14\n";

++id1(get_lex);

print "# `$in' ne 21\nnot " unless $in eq 21;
print "ok 15\n";

inc(get_st);

print "# `$blah' ne 22\nnot " unless $blah eq 22;
print "ok 16\n";

inc(get_lex);

print "# `$in' ne 22\nnot " unless $in eq 22;
print "ok 17\n";

inc(id(get_st));

print "# `$blah' ne 23\nnot " unless $blah eq 23;
print "ok 18\n";

inc(id(get_lex));

print "# `$in' ne 23\nnot " unless $in eq 23;
print "ok 19\n";

++inc(id1(id(get_st)));

print "# `$blah' ne 25\nnot " unless $blah eq 25;
print "ok 20\n";

++inc(id1(id(get_lex)));

print "# `$in' ne 25\nnot " unless $in eq 25;
print "ok 21\n";

@a = (1) x 3;
@b = (undef) x 2;
$#c = 3;			# These slots are not fillable.

# Explanation: empty slots contain &sv_undef.

=for disabled constructs

sub a3 {use attrs 'lvalue'; @a}
sub b2 {use attrs 'lvalue'; @b}
sub c4 {use attrs 'lvalue'; @c}

$_ = '';

eval <<'EOE' or $_ = $@;
  ($x, a3, $y, b2, $z, c4, $t) = (34 .. 78);
  1;
EOE

#@out = ($x, a3, $y, b2, $z, c4, $t);
#@in = (34 .. 41, (undef) x 4, 46);
#print "# `@out' ne `@in'\nnot " unless "@out" eq "@in";

print "# '$_'.\nnot "
  unless /Can\'t return an uninitialized value from lvalue subroutine/;
=cut

print "ok 22\n";

my $var;

sub a::var {use attrs 'lvalue'; $var}

"a"->var = 45;

print "# `$var' ne 45\nnot " unless $var eq 45;
print "ok 23\n";

my $oo;
$o = bless \$oo, "a";

$o->var = 47;

print "# `$var' ne 47\nnot " unless $var eq 47;
print "ok 24\n";

sub o {use attrs 'lvalue'; $o}

o->var = 49;

print "# `$var' ne 49\nnot " unless $var eq 49;
print "ok 25\n";

sub nolv () { $x0, $x1 } # Not lvalue

$_ = '';

eval <<'EOE' or $_ = $@;
  nolv = (2,3);
  1;
EOE

print "not "
  unless /Can\'t modify non-lvalue subroutine call in scalar assignment/;
print "ok 26\n";

$_ = '';

eval <<'EOE' or $_ = $@;
  nolv = (2,3) if $_;
  1;
EOE

print "not "
  unless /Can\'t modify non-lvalue subroutine call in scalar assignment/;
print "ok 27\n";

$_ = '';

eval <<'EOE' or $_ = $@;
  &nolv = (2,3) if $_;
  1;
EOE

print "not "
  unless /Can\'t modify non-lvalue subroutine call in scalar assignment/;
print "ok 28\n";

$x0 = $x1 = $_ = undef;
$nolv = \&nolv;

eval <<'EOE' or $_ = $@;
  $nolv->() = (2,3) if $_;
  1;
EOE

print "# '$_', '$x0', '$x1'.\nnot " if defined $_;
print "ok 29\n";

$x0 = $x1 = $_ = undef;
$nolv = \&nolv;

eval <<'EOE' or $_ = $@;
  $nolv->() = (2,3);
  1;
EOE

print "# '$_', '$x0', '$x1'.\nnot "
  unless /Can\'t modify non-lvalue indirect subroutine call/;
print "ok 30\n";

sub lv0 {use attrs 'lvalue';}		# Converted to lv10 in scalar context

$_ = undef;
eval <<'EOE' or $_ = $@;
  lv0 = (2,3);
  1;
EOE

print "# '$_'.\nnot "
  unless /Can\'t return a readonly value from lvalue subroutine/;
print "ok 31\n";

sub lv10 {use attrs 'lvalue';}

$_ = undef;
eval <<'EOE' or $_ = $@;
  (lv0) = (2,3);
  1;
EOE

print "# '$_'.\nnot " if defined $_;
print "ok 32\n";

sub lv1u {use attrs 'lvalue'; undef }

$_ = undef;
eval <<'EOE' or $_ = $@;
  lv1u = (2,3);
  1;
EOE

print "# '$_'.\nnot "
  unless /Can\'t return a readonly value from lvalue subroutine/;
print "ok 33\n";

$_ = undef;
eval <<'EOE' or $_ = $@;
  (lv1u) = (2,3);
  1;
EOE

print "# '$_'.\nnot "
  unless /Can\'t return an uninitialized value from lvalue subroutine/;
print "ok 34\n";

$x = '1234567';
sub lv1t {use attrs 'lvalue'; index $x, 2 }

$_ = undef;
eval <<'EOE' or $_ = $@;
  lv1t = (2,3);
  1;
EOE

print "# '$_'.\nnot "
  unless /Can\'t return a temporary from lvalue subroutine/;
print "ok 35\n";

$_ = undef;
eval <<'EOE' or $_ = $@;
  (lv1t) = (2,3);
  1;
EOE

print "# '$_'.\nnot "
  unless /Can\'t return a temporary from lvalue subroutine/;
print "ok 36\n";

$xxx = 'xxx';
sub xxx () { $xxx }  # Not lvalue
sub lv1tmp {use attrs 'lvalue'; xxx }			# is it a TEMP?

$_ = undef;
eval <<'EOE' or $_ = $@;
  lv1tmp = (2,3);
  1;
EOE

print "# '$_'.\nnot "
  unless /Can\'t return a temporary from lvalue subroutine/;
print "ok 37\n";

$_ = undef;
eval <<'EOE' or $_ = $@;
  (lv1tmp) = (2,3);
  1;
EOE

print "# '$_'.\nnot "
  unless /Can\'t return a temporary from lvalue subroutine/;
print "ok 38\n";

sub xxx () { 'xxx' } # Not lvalue
sub lv1tmpr {use attrs 'lvalue'; xxx }			# is it a TEMP?

$_ = undef;
eval <<'EOE' or $_ = $@;
  lv1tmpr = (2,3);
  1;
EOE

print "# '$_'.\nnot "
  unless /Can\'t return a readonly value from lvalue subroutine/;
print "ok 39\n";

$_ = undef;
eval <<'EOE' or $_ = $@;
  (lv1tmpr) = (2,3);
  1;
EOE

print "# '$_'.\nnot "
  unless /Can\'t return a readonly value from lvalue subroutine/;
print "ok 40\n";

=for disabled constructs

sub lva {use attrs 'lvalue';@a}

$_ = undef;
@a = ();
$a[1] = 12;
eval <<'EOE' or $_ = $@;
  (lva) = (2,3);
  1;
EOE

print "# '$_'.\nnot "
  unless /Can\'t return an uninitialized value from lvalue subroutine/;
print "ok 41\n";

$_ = undef;
@a = ();
$a[0] = undef;
$a[1] = 12;
eval <<'EOE' or $_ = $@;
  (lva) = (2,3);
  1;
EOE

print "# '$_'.\nnot " unless "'@a' $_" eq "'2 3' ";
print "ok 42\n";

$_ = undef;
@a = ();
$a[0] = undef;
$a[1] = 12;
eval <<'EOE' or $_ = $@;
  (lva) = (2,3);
  1;
EOE

print "# '$_'.\nnot " unless "'@a' $_" eq "'2 3' ";
print "ok 43\n";

=cut

print "ok $_\n" for 41..43;

sub lv1n {use attrs 'lvalue'; $newvar }

$_ = undef;
eval <<'EOE' or $_ = $@;
  lv1n = (3,4);
  1;
EOE

print "# '$_', '$newvar'.\nnot " unless "'$newvar' $_" eq "'4' ";
print "ok 44\n";

sub lv1nn {use attrs 'lvalue'; $nnewvar }

$_ = undef;
eval <<'EOE' or $_ = $@;
  (lv1nn) = (3,4);
  1;
EOE

print "# '$_'.\nnot " unless "'$nnewvar' $_" eq "'3' ";
print "ok 45\n";

$a = \&lv1nn;
$a->() = 8;
print "# '$nnewvar'.\nnot " unless $nnewvar eq '8';
print "ok 46\n";