Re: Regex Match() Abortion

From: eydelber (eydelber_at_[hidden])
Date: 2002-12-04 14:09:56

This test is completely stripped down, should work for you on Win32, 
and still reproduces the problem:

#include <iostream>
#include <string>
#include <boost/regex.hpp>

using namespace std;
using namespace boost;

const string re_ID = "[\\w\\-]+";
const string re_TYPES = "int|decimal|datetime|varchar";
const string re_BASIC_COLDEF = "(_ID_) (_TYPES_)( not null)?( 
unique)?( default ((\\d+(\\.\\d+)?)|(\"[^\"]*\")))?( unique)?";
const string re_EXT_COLDEF = re_BASIC_COLDEF+"( first| after 
(_ID_))?";

string replaceStr(string Source, const string& Find, const string& 
Replacement) {
        string::size_type Length = Find.length();
        string::size_type ReplacementLength = Replacement.length();
        string::size_type Pos = 0;
        while((Pos = Source.find(Find,Pos)) != string::npos) {
                Source.replace(Pos,Length,Replacement);
                Pos += ReplacementLength;
        }
        return Source;
}

string replaceMacros(string reg) {
        return(replaceStr(replaceStr(replaceStr(replaceStr(replaceStr
(reg," ","\\s+"),"_COL_",re_BASIC_COLDEF),"_ECOL_",re_EXT_COLDEF),"_I
D_",re_ID),"_TYPES_",re_TYPES));
}

int main() {
        string sql = "insert into test 
(vklajsfkljsdfkjsldfsdjkfdslklfsdjklfsjfsd) values (1)";
        string checks[] = {
                /* 0 */  "create table (_ID_) (\\(((\\s*,?
\\s*_COL_\\s*)+)\\))",
                /* 1 */  "show tables",
                /* 2 */  "drop table (_ID_)",
                /* 3 */  "show database",
                /* 4 */  "desc( table)? (_ID_)",
                /* 5 */  "alter table (_ID_) add( column)? (_ECOL_)",
                /* 6 */  "alter table (_ID_) drop( column)? (_ID_)",
                /* 7 */  "alter table (_ID_) add( column)? 
\\(((\\s*,?\\s*_ECOL_\\s*)+)\\)",
                /* 8 */  "rename table (_ID_) (to|as) (_ID_)",
                /* 9 */  "alter table (_ID_) alter( column)? (_ID_) 
(set default ((\\d+(\\.\\d+)?)|(\"[^\"]*\"))|drop default)",
                /* 10 */ "alter table (_ID_) modify( column)? 
(_COL_)",
                /* 11 */ "alter table (_ID_) change( column)? (_ID_) 
(_COL_)",
                /* 12 */ "alter table (_ID_) rename( to| as) (_ID_)",
                /* 13 */ "insert( into)? (_ID_)( \\(((\\s*,?\\s*
(_ID_)\\s*)+)\\))? values \\(((\\s*,?\\s*((\\d+(\\.\\d+)?)|(\"[^\"]
*\"))\\s*)+)\\)"
        };
        int checksLength = sizeof checks / sizeof *checks;
        int i;
        for(i=0;i<checksLength;i++) {
                checks[i] = "^(\\s*"+replaceMacros(checks[i])
+"\\s*;?)$";
        }
        RegEx sqlRegex;
        for(i=0;i<checksLength;i++) {
                sqlRegex.SetExpression(checks[i],true);
                if(sqlRegex.Match(sql)) {
                        break;
                }
        }
        cout << "Finished." << endl;
        return 0;
}

If you change the "sql" string to match any other of the 12 cases, 
they work fine. Only with the last case does it not work.

Again, thanks a lot for your time,
Kevin

--- In Boost-Users_at_y..., "John Maddock" <john_maddock_at_c...> wrote:
> > Sorry, I didn't qualify my problem correctly.  The problem comes 
in
> > when the column list is too long, opposite of what you tested.
> > Also, I doubt the problem is duplicable in such certain 
conditions,
> > so if you want to try the full program, it will take about 5 
minutes
> > to download and test and then try the same test, except with the
> > gibberish in the first ()'s and not the second ()'s.
> 
> I tried to look at your code, but can't compile because of:
> 
> #include <xmlparse.h>
> 
> whatever that is.
> 
> If you want me to look at this, can you please try and boil it 
down to a
> reproducable test case, or failing that mail me a .zip file 
privately
> containing everything needed to build the app, plus a text file 
containing
> the input that demonstrates the problem.  Remember that I'm likely 
to be
> building on Win32 not linux: I know next to nothing about 
debugging gcc
> built apps, so there's no mileage to be gained by me trying to do 
that
> rather than you.
> 
> John Maddock
> http://ourworld.compuserve.com/homepages/john_maddock/index.htm