[p5sagit/p5-mst-13.2.git] / t / lib / warnings / toke

toke.c	AOK

    we seem to have lost a few ambiguous warnings!!

 
 		$a = <<;
 		Use of comma-less variable list is deprecated 
		(called 3 times via depcom)

     \1 better written as $1 
 	use warnings 'syntax' ;
 	s/(abc)/\1/;
 
     warn(warn_nosemi) 
     Semicolon seems to be missing
	$a = 1
	&time ;


     Reversed %c= operator 
	my $a =+ 2 ;
	$a =- 2 ;
	$a =* 2 ;
	$a =% 2 ;
	$a =& 2 ;
	$a =. 2 ;
	$a =^ 2 ;
	$a =| 2 ;
	$a =< 2 ;
	$a =/ 2 ;

     Multidimensional syntax %.*s not supported 
	my $a = $a[1,2] ;

     You need to quote \"%s\"" 
	sub fred {} ; $SIG{TERM} = fred;

     Scalar value %.*s better written as $%.*s" 
	@a[3] = 2;
	@a{3} = 2;

     Can't use \\%c to mean $%c in expression 
	$_ = "ab" ; s/(ab)/\1/e;

     Unquoted string "abc" may clash with future reserved word at - line 3.
     warn(warn_reserved	
	$a = abc;

     Possible attempt to separate words with commas 
	@a = qw(a, b, c) ;

     Possible attempt to put comments in qw() list 
	@a = qw(a b # c) ;

     %s (...) interpreted as function 
	print ("")
	printf ("")
	sort ("")

     Ambiguous use of %c{%s%s} resolved to %c%s%s 
	$a = ${time[2]}
	$a = ${time{2}}


     Ambiguous use of %c{%s} resolved to %c%s
	$a = ${time}
	sub fred {} $a = ${fred}

     Misplaced _ in number 
	$a = 1_2;
	$a = 1_2345_6;

    Bareword \"%s\" refers to nonexistent package
	$a = FRED:: ;

    Ambiguous call resolved as CORE::%s(), qualify as such or use &
	sub time {} 
	my $a = time()

    Unrecognized escape \\%c passed through
        $a = "\m" ;

    %s number > %s non-portable
        my $a =  0b011111111111111111111111111111110 ;
        $a =  0b011111111111111111111111111111111 ;
        $a =  0b111111111111111111111111111111111 ;
        $a =  0x0fffffffe ;
        $a =  0x0ffffffff ;
        $a =  0x1ffffffff ;
        $a =  0037777777776 ;
        $a =  0037777777777 ;
        $a =  0047777777777 ;

    Integer overflow in binary number
        my $a =  0b011111111111111111111111111111110 ;
        $a =  0b011111111111111111111111111111111 ;
        $a =  0b111111111111111111111111111111111 ;
        $a =  0x0fffffffe ;
        $a =  0x0ffffffff ;
        $a =  0x1ffffffff ;
        $a =  0037777777776 ;
        $a =  0037777777777 ;
        $a =  0047777777777 ;

    dump() better written as CORE::dump()

    Use of /c modifier is meaningless without /g     

    Use of /c modifier is meaningless in s///

    Mandatory Warnings
    ------------------
    Use of "%s" without parentheses is ambiguous	[check_uni]
        rand + 4 

    Ambiguous use of -%s resolved as -&%s() 		[yylex]
        sub fred {} ; - fred ;

    Precedence problem: open %.*s should be open(%.*s)	[yylex]
    	open FOO || die;

    Operator or semicolon missing before %c%s		[yylex]
    Ambiguous use of %c resolved as operator %c
        *foo *foo

__END__
# toke.c 
use warnings 'deprecated' ;
format STDOUT =
@<<<  @|||  @>>>  @>>>
$a    $b    "abc" 'def'
.
no warnings 'deprecated' ;
format STDOUT =
@<<<  @|||  @>>>  @>>>
$a    $b    "abc" 'def'
.
EXPECT
Use of comma-less variable list is deprecated at - line 5.
Use of comma-less variable list is deprecated at - line 5.
Use of comma-less variable list is deprecated at - line 5.
########
# toke.c
use warnings 'deprecated' ;
$a = <<;

no warnings 'deprecated' ;
$a = <<;

EXPECT
Use of bare << to mean <<"" is deprecated at - line 3.
########
# toke.c
use warnings 'syntax' ;
s/(abc)/\1/;
no warnings 'syntax' ;
s/(abc)/\1/;
EXPECT
\1 better written as $1 at - line 3.
########
# toke.c
use warnings 'semicolon' ;
$a = 1
&time ;
no warnings 'semicolon' ;
$a = 1
&time ;
EXPECT
Semicolon seems to be missing at - line 3.
########
# toke.c
use warnings 'syntax' ;
my $a =+ 2 ;
$a =- 2 ;
$a =* 2 ;
$a =% 2 ;
$a =& 2 ;
$a =. 2 ;
$a =^ 2 ;
$a =| 2 ;
$a =< 2 ;
$a =/ 2 ;
EXPECT
Reversed += operator at - line 3.
Reversed -= operator at - line 4.
Reversed *= operator at - line 5.
Reversed %= operator at - line 6.
Reversed &= operator at - line 7.
Reversed .= operator at - line 8.
Reversed ^= operator at - line 9.
Reversed |= operator at - line 10.
Reversed <= operator at - line 11.
syntax error at - line 8, near "=."
syntax error at - line 9, near "=^"
syntax error at - line 10, near "=|"
Unterminated <> operator at - line 11.
########
# toke.c
no warnings 'syntax' ;
my $a =+ 2 ;
$a =- 2 ;
$a =* 2 ;
$a =% 2 ;
$a =& 2 ;
$a =. 2 ;
$a =^ 2 ;
$a =| 2 ;
$a =< 2 ;
$a =/ 2 ;
EXPECT
syntax error at - line 8, near "=."
syntax error at - line 9, near "=^"
syntax error at - line 10, near "=|"
Unterminated <> operator at - line 11.
########
# toke.c
use warnings 'syntax' ;
my $a = $a[1,2] ;
no warnings 'syntax' ;
my $a = $a[1,2] ;
EXPECT
Multidimensional syntax $a[1,2] not supported at - line 3.
########
# toke.c
use warnings 'syntax' ;
sub fred {} ; $SIG{TERM} = fred;
no warnings 'syntax' ;
$SIG{TERM} = fred;
EXPECT
You need to quote "fred" at - line 3.
########
# toke.c
use warnings 'syntax' ;
@a[3] = 2;
@a{3} = 2;
no warnings 'syntax' ;
@a[3] = 2;
@a{3} = 2;
EXPECT
Scalar value @a[3] better written as $a[3] at - line 3.
Scalar value @a{3} better written as $a{3} at - line 4.
########
# toke.c
use warnings 'syntax' ;
$_ = "ab" ; 
s/(ab)/\1/e;
no warnings 'syntax' ;
$_ = "ab" ; 
s/(ab)/\1/e;
EXPECT
Can't use \1 to mean $1 in expression at - line 4.
########
# toke.c
use warnings 'reserved' ;
$a = abc;
$a = { def

=> 1 };
no warnings 'reserved' ;
$a = abc;
EXPECT
Unquoted string "abc" may clash with future reserved word at - line 3.
########
# toke.c
use warnings 'qw' ;
@a = qw(a, b, c) ;
no warnings 'qw' ;
@a = qw(a, b, c) ;
EXPECT
Possible attempt to separate words with commas at - line 3.
########
# toke.c
use warnings 'qw' ;
@a = qw(a b #) ;
no warnings 'qw' ;
@a = qw(a b #) ;
EXPECT
Possible attempt to put comments in qw() list at - line 3.
########
# toke.c
use warnings 'syntax' ;
print ("");
print ("") and $x = 1;
print ("") or die;
print ("") // die;
print (1+2) * 3 if 0; # only this one should warn
print (1+2) if 0;
EXPECT
print (...) interpreted as function at - line 7.
########
# toke.c
no warnings 'syntax' ;
print ("")
EXPECT

########
# toke.c
use warnings 'syntax' ;
printf ("");
printf ("") . '';
EXPECT
printf (...) interpreted as function at - line 4.
########
# toke.c
no warnings 'syntax' ;
printf ("")
EXPECT

########
# toke.c
use warnings 'syntax' ;
sort ("");
sort ("") . '';
EXPECT
sort (...) interpreted as function at - line 4.
########
# toke.c
no warnings 'syntax' ;
sort ("")
EXPECT

########
# toke.c
use warnings 'ambiguous' ;
$a = ${time[2]};
no warnings 'ambiguous' ;
$a = ${time[2]};
EXPECT
Ambiguous use of ${time[...]} resolved to $time[...] at - line 3.
########
# toke.c
use warnings 'ambiguous' ;
$a = ${time{2}};
EXPECT
Ambiguous use of ${time{...}} resolved to $time{...} at - line 3.
########
# toke.c
no warnings 'ambiguous' ;
$a = ${time{2}};
EXPECT

########
# toke.c
use warnings 'ambiguous' ;
$a = ${time} ;
no warnings 'ambiguous' ;
$a = ${time} ;
EXPECT
Ambiguous use of ${time} resolved to $time at - line 3.
########
# toke.c
use warnings 'ambiguous' ;
sub fred {}
$a = ${fred} ;
no warnings 'ambiguous' ;
$a = ${fred} ;
EXPECT
Ambiguous use of ${fred} resolved to $fred at - line 4.
########
# toke.c
use warnings 'syntax' ;
$a = _123; print "$a\n";		#( 3	string)
$a = 1_23; print "$a\n";
$a = 12_3; print "$a\n";
$a = 123_; print "$a\n";		#  6
$a = _+123; print "$a\n";		#  7	string)
$a = +_123; print "$a\n";		#( 8	string)
$a = +1_23; print "$a\n";
$a = +12_3; print "$a\n";
$a = +123_; print "$a\n";		# 11
$a = _-123; print "$a\n";		#(12	string)
$a = -_123; print "$a\n";		#(13	string)
$a = -1_23; print "$a\n";
$a = -12_3; print "$a\n";
$a = -123_; print "$a\n";		# 16
$a = 123._456; print "$a\n";		# 17
$a = 123.4_56; print "$a\n";
$a = 123.45_6; print "$a\n";
$a = 123.456_; print "$a\n";		# 20
$a = +123._456; print "$a\n";		# 21
$a = +123.4_56; print "$a\n";	
$a = +123.45_6; print "$a\n";	
$a = +123.456_; print "$a\n";		# 24
$a = -123._456; print "$a\n";		# 25
$a = -123.4_56; print "$a\n";	
$a = -123.45_6; print "$a\n";
$a = -123.456_; print "$a\n";		# 28
$a = 123.456E_12; printf("%.0f\n", $a);	# 29
$a = 123.456E1_2; printf("%.0f\n", $a);
$a = 123.456E12_; printf("%.0f\n", $a);	# 31
$a = 123.456E_+12; printf("%.0f\n", $a);	# 32
$a = 123.456E+_12; printf("%.0f\n", $a);	# 33
$a = 123.456E+1_2; printf("%.0f\n", $a);
$a = 123.456E+12_; printf("%.0f\n", $a);	# 35
$a = 123.456E_-12; print "$a\n";	# 36
$a = 123.456E-_12; print "$a\n";	# 37
$a = 123.456E-1_2; print "$a\n";
$a = 123.456E-12_; print "$a\n";	# 39
$a = 1__23; print "$a\n";		# 40
$a = 12.3__4; print "$a\n";		# 41
$a = 12.34e1__2; printf("%.0f\n", $a);	# 42
no warnings 'syntax' ;
$a = _123; print "$a\n";
$a = 1_23; print "$a\n";
$a = 12_3; print "$a\n";
$a = 123_; print "$a\n";
$a = _+123; print "$a\n";
$a = +_123; print "$a\n";
$a = +1_23; print "$a\n";
$a = +12_3; print "$a\n";
$a = +123_; print "$a\n";
$a = _-123; print "$a\n";
$a = -_123; print "$a\n";
$a = -1_23; print "$a\n";
$a = -12_3; print "$a\n";
$a = -123_; print "$a\n";
$a = 123._456; print "$a\n";
$a = 123.4_56; print "$a\n";
$a = 123.45_6; print "$a\n";
$a = 123.456_; print "$a\n";
$a = +123._456; print "$a\n";
$a = +123.4_56; print "$a\n";
$a = +123.45_6; print "$a\n";
$a = +123.456_; print "$a\n";
$a = -123._456; print "$a\n";
$a = -123.4_56; print "$a\n";
$a = -123.45_6; print "$a\n";
$a = -123.456_; print "$a\n";
$a = 123.456E_12; printf("%.0f\n", $a);
$a = 123.456E1_2; printf("%.0f\n", $a);
$a = 123.456E12_; printf("%.0f\n", $a);
$a = 123.456E_+12; printf("%.0f\n", $a);
$a = 123.456E+_12; printf("%.0f\n", $a);
$a = 123.456E+1_2; printf("%.0f\n", $a);
$a = 123.456E+12_; printf("%.0f\n", $a);
$a = 123.456E_-12; print "$a\n";
$a = 123.456E-_12; print "$a\n";
$a = 123.456E-1_2; print "$a\n";
$a = 123.456E-12_; print "$a\n";
$a = 1__23; print "$a\n";
$a = 12.3__4; print "$a\n";
$a = 12.34e1__2; printf("%.0f\n", $a);
EXPECT
OPTIONS regex
Misplaced _ in number at - line 6.
Misplaced _ in number at - line 11.
Misplaced _ in number at - line 16.
Misplaced _ in number at - line 17.
Misplaced _ in number at - line 20.
Misplaced _ in number at - line 21.
Misplaced _ in number at - line 24.
Misplaced _ in number at - line 25.
Misplaced _ in number at - line 28.
Misplaced _ in number at - line 29.
Misplaced _ in number at - line 31.
Misplaced _ in number at - line 32.
Misplaced _ in number at - line 33.
Misplaced _ in number at - line 35.
Misplaced _ in number at - line 36.
Misplaced _ in number at - line 37.
Misplaced _ in number at - line 39.
Misplaced _ in number at - line 40.
Misplaced _ in number at - line 41.
Misplaced _ in number at - line 42.
_123
123
123
123
123
_123
123
123
123
-123
-_123
-123
-123
-123
123.456
123.456
123.456
123.456
123.456
123.456
123.456
123.456
-123.456
-123.456
-123.456
-123.456
123456000000000
123456000000000
123456000000000
123456000000000
123456000000000
123456000000000
123456000000000
1.23456e-0?10
1.23456e-0?10
1.23456e-0?10
1.23456e-0?10
123
12.34
12340000000000
_123
123
123
123
123
_123
123
123
123
-123
-_123
-123
-123
-123
123.456
123.456
123.456
123.456
123.456
123.456
123.456
123.456
-123.456
-123.456
-123.456
-123.456
123456000000000
123456000000000
123456000000000
123456000000000
123456000000000
123456000000000
123456000000000
1.23456e-0?10
1.23456e-0?10
1.23456e-0?10
1.23456e-0?10
123
12.34
12340000000000
########
# toke.c
use warnings 'bareword' ;
#line 25 "bar"
$a = FRED:: ;
no warnings 'bareword' ;
#line 25 "bar"
$a = FRED:: ;
EXPECT
Bareword "FRED::" refers to nonexistent package at bar line 25.
########
# toke.c
use warnings 'ambiguous' ;
sub time {}
my $a = time() ;
no warnings 'ambiguous' ;
my $b = time() ;
EXPECT
Ambiguous call resolved as CORE::time(), qualify as such or use & at - line 4.
########
# toke.c
use warnings ;
eval <<'EOE';
#  line 30 "foo"
warn "yelp";
{
  $_ = " \x{123} " ;
}
EOE
EXPECT
yelp at foo line 30.
########
# toke.c
my $a = rand + 4 ;
EXPECT
Warning: Use of "rand" without parentheses is ambiguous at - line 2.
########
# toke.c
$^W = 0 ;
my $a = rand + 4 ;
{
    no warnings 'ambiguous' ;
    $a = rand + 4 ;
    use warnings 'ambiguous' ;
    $a = rand + 4 ;
}
$a = rand + 4 ;
EXPECT
Warning: Use of "rand" without parentheses is ambiguous at - line 3.
Warning: Use of "rand" without parentheses is ambiguous at - line 8.
Warning: Use of "rand" without parentheses is ambiguous at - line 10.
########
# toke.c
use warnings "ambiguous";
print for keys %+; # should not warn
EXPECT
########
# toke.c
sub fred {};
-fred ;
EXPECT
Ambiguous use of -fred resolved as -&fred() at - line 3.
########
# toke.c
$^W = 0 ;
sub fred {} ;
-fred ;
{
    no warnings 'ambiguous' ;
    -fred ;
    use warnings 'ambiguous' ;
    -fred ;
}
-fred ;
EXPECT
Ambiguous use of -fred resolved as -&fred() at - line 4.
Ambiguous use of -fred resolved as -&fred() at - line 9.
Ambiguous use of -fred resolved as -&fred() at - line 11.
########
# toke.c
open FOO || time;
EXPECT
Precedence problem: open FOO should be open(FOO) at - line 2.
########
# toke.c (and [perl #16184])
open FOO => "<&0"; close FOO;
EXPECT
########
# toke.c
$^W = 0 ;
open FOO || time;
{
    no warnings 'precedence' ;
    open FOO || time;
    use warnings 'precedence' ;
    open FOO || time;
}
open FOO || time;
EXPECT
Precedence problem: open FOO should be open(FOO) at - line 3.
Precedence problem: open FOO should be open(FOO) at - line 8.
Precedence problem: open FOO should be open(FOO) at - line 10.
########
# toke.c
$^W = 0 ;
*foo *foo ;
{
    no warnings 'ambiguous' ;
    *foo *foo ;
    use warnings 'ambiguous' ;
    *foo *foo ;
}
*foo *foo ;
EXPECT
Operator or semicolon missing before *foo at - line 3.
Ambiguous use of * resolved as operator * at - line 3.
Operator or semicolon missing before *foo at - line 8.
Ambiguous use of * resolved as operator * at - line 8.
Operator or semicolon missing before *foo at - line 10.
Ambiguous use of * resolved as operator * at - line 10.
########
# toke.c
use warnings 'misc' ;
my $a = "\m" ;
no warnings 'misc' ;
$a = "\m" ;
EXPECT
Unrecognized escape \m passed through at - line 3.
########
# toke.c
use warnings 'portable' ;
my $a =  0b011111111111111111111111111111110 ;
   $a =  0b011111111111111111111111111111111 ;
   $a =  0b111111111111111111111111111111111 ;
   $a =  0x0fffffffe ;
   $a =  0x0ffffffff ;
   $a =  0x1ffffffff ;
   $a =  0037777777776 ;
   $a =  0037777777777 ;
   $a =  0047777777777 ;
no warnings 'portable' ;
   $a =  0b011111111111111111111111111111110 ;
   $a =  0b011111111111111111111111111111111 ;
   $a =  0b111111111111111111111111111111111 ;
   $a =  0x0fffffffe ;
   $a =  0x0ffffffff ;
   $a =  0x1ffffffff ;
   $a =  0037777777776 ;
   $a =  0037777777777 ;
   $a =  0047777777777 ;
EXPECT
Binary number > 0b11111111111111111111111111111111 non-portable at - line 5.
Hexadecimal number > 0xffffffff non-portable at - line 8.
Octal number > 037777777777 non-portable at - line 11.
########
# toke.c
use warnings 'overflow' ;
my $a =  0b011111111111111111111111111111110 ;
   $a =  0b011111111111111111111111111111111 ;
   $a =  0b10000000000000000000000000000000000000000000000000000000000000000 ;
   $a =  0x0fffffffe ;
   $a =  0x0ffffffff ;
   $a =  0x10000000000000000 ;
   $a =  0037777777776 ;
   $a =  0037777777777 ;
   $a =  002000000000000000000000;
no warnings 'overflow' ;
   $a =  0b011111111111111111111111111111110 ;
   $a =  0b011111111111111111111111111111111 ;
   $a =  0b10000000000000000000000000000000000000000000000000000000000000000 ;
   $a =  0x0fffffffe ;
   $a =  0x0ffffffff ;
   $a =  0x10000000000000000 ;
   $a =  0037777777776 ;
   $a =  0037777777777 ;
   $a =  002000000000000000000000;
EXPECT
Integer overflow in binary number at - line 5.
Integer overflow in hexadecimal number at - line 8.
Integer overflow in octal number at - line 11.
########
# toke.c
BEGIN { $^C = 1; }
use warnings 'misc';
dump;
CORE::dump;
EXPECT
dump() better written as CORE::dump() at - line 4.
- syntax OK
########
# toke.c
use warnings 'misc';
use subs qw/dump/;
sub dump { print "no warning for overriden dump\n"; }
dump;
EXPECT
no warning for overriden dump
########
# toke.c
use warnings 'ambiguous';
"@mjd_previously_unused_array";        
no warnings 'ambiguous';
"@mjd_previously_unused_array";        
EXPECT
Possible unintended interpolation of @mjd_previously_unused_array in string at - line 3.
########
# toke.c
# 20020328 mjd-perl-patch+@plover.com at behest of jfriedl@yahoo.com
use warnings 'regexp';
"foo" =~ /foo/c;
"foo" =~ /foo/cg;
no warnings 'regexp';
"foo" =~ /foo/c;
"foo" =~ /foo/cg;
EXPECT
Use of /c modifier is meaningless without /g at - line 4.
########
# toke.c
# 20020328 mjd-perl-patch+@plover.com at behest of jfriedl@yahoo.com
use warnings 'regexp';
$_ = "ab" ; 
s/ab/ab/c;
s/ab/ab/cg;
no warnings 'regexp';
s/ab/ab/c;
s/ab/ab/cg;
EXPECT
Use of /c modifier is meaningless in s/// at - line 5.
Use of /c modifier is meaningless in s/// at - line 6.
########
-wa
# toke.c
# 20020414 mjd-perl-patch+@plover.com # -a flag should suppress these warnings
print "@F\n";
EXPECT

########
-w
# toke.c
# 20020414 mjd-perl-patch+@plover.com # -a flag should suppress these warnings
print "@F\n";
EXPECT
Possible unintended interpolation of @F in string at - line 4.
Name "main::F" used only once: possible typo at - line 4.
########
-wa
# toke.c
# 20020414 mjd-perl-patch+@plover.com
EXPECT

########
# toke.c
# 20020414 mjd-perl-patch+@plover.com
# In 5.7.3, this emitted "Possible unintended interpolation" warnings
use warnings 'ambiguous';
$s = "(@-)(@+)";
EXPECT

########
# toke.c
# mandatory warning
eval q/if ($a) { } elseif ($b) { }/;
no warnings "syntax";
eval q/if ($a) { } elseif ($b) { }/;
EXPECT
elseif should be elsif at (eval 1) line 1.
########
# toke.c
# mandatory warning
eval q/5 6/;
no warnings "syntax";
eval q/5 6/;
EXPECT
Number found where operator expected at (eval 1) line 1, near "5 6"
	(Missing operator before  6?)
########
# toke.c
use warnings "syntax";
$_ = $a = 1;
$a !=~  /1/;
$a !=~ m#1#;
$a !=~/1/;
$a !=~ ?/?;
$a !=~ y/1//;
$a !=~ tr/1//;
$a !=~ s/1//;
$a != ~/1/;
no warnings "syntax";
$a !=~  /1/;
$a !=~ m#1#;
$a !=~/1/;
$a !=~ ?/?;
$a !=~ y/1//;
$a !=~ tr/1//;
$a !=~ s/1//;
EXPECT
!=~ should be !~ at - line 4.
!=~ should be !~ at - line 5.
!=~ should be !~ at - line 6.
!=~ should be !~ at - line 7.
!=~ should be !~ at - line 8.
!=~ should be !~ at - line 9.
!=~ should be !~ at - line 10.
########
# toke.c
our $foo :unique;
use warnings 'deprecated';
our $bar :unique;
EXPECT
Use of :unique is deprecated at - line 4.
########
# toke.c
use warnings "syntax";
sub proto_after_array(@$);
sub proto_after_arref(\@$);
sub proto_after_arref2(\[@$]);
sub proto_after_arref3(\[@$]_);
sub proto_after_hash(%$);
sub proto_after_hashref(\%$);
sub proto_after_hashref2(\[%$]);
sub underscore_last_pos($_);
sub underscore2($_;$);
sub underscore_fail($_$);
sub underscore_after_at(@_);
no warnings "syntax";
sub proto_after_array(@$);
sub proto_after_hash(%$);
sub underscore_fail($_$);
EXPECT
Prototype after '@' for main::proto_after_array : @$ at - line 3.
Prototype after '%' for main::proto_after_hash : %$ at - line 7.
Illegal character after '_' in prototype for main::underscore_fail : $_$ at - line 12.
Prototype after '@' for main::underscore_after_at : @_ at - line 13.
########
# toke.c
use warnings "ambiguous";
"foo\nn" =~ /^foo$\n/;
"foo\nn" =~ /^foo${\}n/;
my $foo = qr/^foo$\n/;
my $bar = qr/^foo${\}n/;
no warnings "ambiguous";
"foo\nn" =~ /^foo$\n/;
"foo\nn" =~ /^foo${\}n/;
my $foo = qr/^foo$\n/;
my $bar = qr/^foo${\}n/;
EXPECT
Possible unintended interpolation of $\ in regex at - line 3.
Possible unintended interpolation of $\ in regex at - line 5.