Re: [cdt-core-dev] Bug Fix for Scanner #ifdef

[John Camelon <jcamelon@xxxxxxxxxx>]

Hi Keithen, 

I see the bug, but I do not see how
it actually affected clients.  How did you discover this?
I've applied a variation on the patch,
as our sources have changed somewhat.  

Thanks,
JohnC
www.eclipse.org/cdt

cdt-core-dev-admin@xxxxxxxxxxx wrote on 06/10/2004
08:24:03 PM:

> I have found a bug and fixed it in the CDT 1.2.1 sources we are 
> working on. I have checked the latest 2.0 sources i have, M7, and
> the bug was still there. So i am sending this in for someone to 
> check the latest sources to see if it still applies.
> 
> The code being parsed is:
> #ifdef __X__
>    // comment
> #endif
> 
> In the scanner code below, the #ifdef has set the passOnToClient 
> flag to false and we are now skipping source code like crazy. Only
> stopping to check for # directives with the one exception of 
> commenting them out. However, as we are skipping text that is not
a 
> '#', in the case of having "//", our first '/' passes the
not # test
> and then we immediately do a c = getChar(), throwing away that 
> comment character before we test it. The defective code from 2.0 M7
> is below and my fix at the bottom.
> 
> Hope it helps.
> 
> -Keithen
> 
> ---------------------------------------------------------------------------------------------------------------------------
> 
> From CDT 2.0M7 Scanner.java:
> 
>    public IToken nextToken( boolean pasting, boolean 
> lookingForNextAlready ) throws ScannerException, EndOfFileException
>    {
> // Missing code //
> 
>       int c = getChar();
> 
>       while (c != NOCHAR) {
>          if ( ! passOnToClient ) {
>                    
 
>             while (c != NOCHAR &&
c != '#' ) 
>             {
>                c = getChar();
>                if( c == '/'
)
>                {
>                   c =
getChar();
>                   if(
c == '/' )
>                   {
>                    
 skipOverSinglelineComment();
>                    
 c = getChar();
>                    
 continue;
>                   }
>                   else
if( c == '*' )
>                   {
>                    
 skipOverMultilineComment();
>                    
 c = getChar();
>                    
 continue;
>                   }
>                }
>             }
>             
>             if( c == NOCHAR )
> 
> ---------------------------------------------------------------------------------------------------------------------------
> 
> My fix:
> 
>             while (c != NOCHAR &&
c != '#' ) 
>             {
>                if( c == '/'
)
>                {
>                   c =
getChar();
>                   if(
c == '/' )
>                   {
>                    
 skipOverSinglelineComment();
>                   }
>                   else
if( c == '*' )
>                   {
>                    
 skipOverMultilineComment();
>                   }
>                }
>                c = getChar();
>             }
> 
> 
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