#!

use Smart::Comments;
use strict;
use warnings;


    my $np;
    $np=qr/
             (?:\(                    # Capture the opening "("
                 (?:                  # 
                     '(?:[^']|\')*?'  #' a single quote string
                     |"(?:[^']|\")*?" #" a double quote string
                     | [^()]          # not a parentheses
                     | (??{$np})
                 )*
             \))                      # and the closing ")"
         /ix; 
    my $string;
    my $re;

    $string=<<'__EOString__';
        SELECT "SELECT * FROM table1 WHERE ...",'FROM WHERE' SQL FROM table2 join(select from here to where eternity) WHERE ...
__EOString__
    $re=qr/
           ^([^'"(]* (?:"(?:[^']|\")*?"|'(?:[^']|\')*?'|$np)? )* 
           [^'"(]* 
           (\bFROM\b
               ([^'"(]* (?:"(?:[^']|\")*?"|'(?:[^']|\')*?'|$np)? )* 
               [^'"(]*?
           \bWHERE\b)
          /ix; # works

    ### $string
    while ($string =~ m{$re}ig) {
        ### @-
        ### @+
        ### $1
        ### $2
        ### $3
         };
    exit;

##</code><code>##

### $string: '        SELECT "SELECT * FROM table1 WHERE ..." "FROM WHERE"SQL FROM table2 join(select my mother from here to where eternity) WHERE ...'
Complex regular subexpression recursion limit (32766) exceeded at RE.pl line 45.
### @-: '0',
###     '64',
###     '64',
###     '127'
### @+: '132',
###     '64',
###     '132',
###     '127'            
### $1: '' 
### $2: 'FROM table2 join(select my mother from here to where eternity) WHERE'                                                      
### $3: ''