regcomp.c	AOK

  Strange *+?{} on zero-length expression	[S_study_chunk]
	/(?=a)?/

  %.*s matches null string many times   	[S_regpiece]
	$a = "ABC123" ; $a =~ /(?=a)*/'

  /%.127s/: Unrecognized escape \\%c passed through	[S_regatom] 
  	$x = '\m' ; /$x/

  Character class [:%.*s:] unknown	[S_regpposixcc]

  Character class syntax [. .] is reserved for future extensions [S_regpposixcc]

  Character class syntax [= =] is reserved for future extensions [S_checkposixcc]

  Character class syntax [%c %c] belongs inside character classes [S_checkposixcc] 
  
  /%.127s/: false [] range \"%*.*s\" in regexp [S_regclass]

  /%.127s/: false [] range \"%*.*s\" in regexp [S_regclassutf8]

  /%.127s/: Unrecognized escape \\%c in character class passed through"	[S_regclass] 

  /%.127s/: Unrecognized escape \\%c in character class passed through"	[S_regclassutf8] 

__END__
# regcomp.c [S_regpiece]
use warnings 'regexp' ;
my $a = "ABC123" ; 
$a =~ /(?=a)*/ ;
no warnings 'regexp' ;
$a =~ /(?=a)*/ ;
EXPECT
(?=a)* matches null string many times at - line 4.
########
# regcomp.c [S_study_chunk]
use warnings 'regexp' ;
$_ = "" ;
/(?=a)?/;
no warnings 'regexp' ;
/(?=a)?/;
EXPECT
Strange *+?{} on zero-length expression at - line 4.
########
# regcomp.c [S_regatom]
$x = '\m' ;
use warnings 'regexp' ;
$a =~ /a$x/ ;
no warnings 'regexp' ;
$a =~ /a$x/ ;
EXPECT
/a\m/: Unrecognized escape \m passed through at - line 4.
########
# regcomp.c [S_regpposixcc S_checkposixcc]
BEGIN { $ENV{PERL_DESTRUCT_LEVEL} = 0 unless $ENV{PERL_DESTRUCT_LEVEL} > 3 }
use warnings 'regexp' ;
$_ = "" ;
/[:alpha:]/;
/[.bar.]/;
/[=zog=]/;
/[[:alpha:]]/;
/[[.foo.]]/;
/[[=bar=]]/;
/[:zog:]/;
/[[:zog:]]/;
no warnings 'regexp' ;
/[:alpha:]/;
/[.foo.]/;
/[=bar=]/;
/[[:alpha:]]/;
/[[.foo.]]/;
/[[=bar=]]/;
/[[:zog:]]/;
/[:zog:]/;
EXPECT
Character class syntax [: :] belongs inside character classes at - line 5.
Character class syntax [. .] belongs inside character classes at - line 6.
Character class syntax [. .] is reserved for future extensions at - line 6.
Character class syntax [= =] belongs inside character classes at - line 7.
Character class syntax [= =] is reserved for future extensions at - line 7.
Character class syntax [. .] is reserved for future extensions at - line 9.
Character class syntax [= =] is reserved for future extensions at - line 10.
Character class syntax [: :] belongs inside character classes at - line 11.
Character class [:zog:] unknown at - line 12.
########
# regcomp.c [S_regclass]
$_ = "";
use warnings 'regexp' ;
/[a-b]/;
/[a-\d]/;
/[\d-b]/;
/[\s-\d]/;
/[\d-\s]/;
/[a-[:digit:]]/;
/[[:digit:]-b]/;
/[[:alpha:]-[:digit:]]/;
/[[:digit:]-[:alpha:]]/;
no warnings 'regexp' ;
/[a-b]/;
/[a-\d]/;
/[\d-b]/;
/[\s-\d]/;
/[\d-\s]/;
/[a-[:digit:]]/;
/[[:digit:]-b]/;
/[[:alpha:]-[:digit:]]/;
/[[:digit:]-[:alpha:]]/;
EXPECT
/[a-\d]/: false [] range "a-\d" in regexp at - line 5.
/[\d-b]/: false [] range "\d-" in regexp at - line 6.
/[\s-\d]/: false [] range "\s-" in regexp at - line 7.
/[\d-\s]/: false [] range "\d-" in regexp at - line 8.
/[a-[:digit:]]/: false [] range "a-[:digit:]" in regexp at - line 9.
/[[:digit:]-b]/: false [] range "[:digit:]-" in regexp at - line 10.
/[[:alpha:]-[:digit:]]/: false [] range "[:alpha:]-" in regexp at - line 11.
/[[:digit:]-[:alpha:]]/: false [] range "[:digit:]-" in regexp at - line 12.
########
# regcomp.c [S_regclassutf8]
BEGIN {
    if (ord("\t") == 5) {
        print "SKIPPED\n# ebcdic regular expression ranges differ.";
        exit 0;
    }
}
use utf8;
$_ = "";
use warnings 'regexp' ;
/[a-b]/;
/[a-\d]/;
/[\d-b]/;
/[\s-\d]/;
/[\d-\s]/;
/[a-[:digit:]]/;
/[[:digit:]-b]/;
/[[:alpha:]-[:digit:]]/;
/[[:digit:]-[:alpha:]]/;
no warnings 'regexp' ;
/[a-b]/;
/[a-\d]/;
/[\d-b]/;
/[\s-\d]/;
/[\d-\s]/;
/[a-[:digit:]]/;
/[[:digit:]-b]/;
/[[:alpha:]-[:digit:]]/;
/[[:digit:]-[:alpha:]]/;
EXPECT
/[a-\d]/: false [] range "a-\d" in regexp at - line 12.
/[\d-b]/: false [] range "\d-" in regexp at - line 13.
/[\s-\d]/: false [] range "\s-" in regexp at - line 14.
/[\d-\s]/: false [] range "\d-" in regexp at - line 15.
/[a-[:digit:]]/: false [] range "a-[:digit:]" in regexp at - line 16.
/[[:digit:]-b]/: false [] range "[:digit:]-" in regexp at - line 17.
/[[:alpha:]-[:digit:]]/: false [] range "[:alpha:]-" in regexp at - line 18.
/[[:digit:]-[:alpha:]]/: false [] range "[:digit:]-" in regexp at - line 19.
########
# regcomp.c [S_regclass S_regclassutf8]
use warnings 'regexp' ;
$a =~ /[a\zb]/ ;
no warnings 'regexp' ;
$a =~ /[a\zb]/ ;
EXPECT
/[a\zb]/: Unrecognized escape \z in character class passed through at - line 3.