[cfe-dev] Stmt.getLocEnd()

[Jordan Rose]

On Feb 4, 2013, at 17:37 , Antoine Trouve <trouve at isit.or.jp> wrote:

> My bad, I was using the function the wrong way.
> 
> But I noticed that I couldn't go through a semicolon using "Lexer::getLocForEndOfToken" if there is a space before the semicolon.
> 
> For instance, let's consider this code:
> 
> 	for(i=0; i<mand(N,N); i++) res ++ ;
> 
> Initially, the SourceLocation retreieved with "getLocEnd()" is before the "++":
> 
> 	for(i=0; i<mand(N,N); i++) res /*HERE*/++ ;
> 
> If I call "Lexer::getLocForEndOfToken", it will point to after "++": nice:
> 
> 	for(i=0; i<mand(N,N); i++) res ++/*HERE*/ ;
> 
> Then if I call again getLocForEndOfToken, the result will point to the exact same location (I need to call "getLocWithOffset")
> 
> 	for(i=0; i<mand(N,N); i++) res ++/*STILL HERE*/ ;
> 
> In the case I don't have any space before the semicolon, the return value of the second call to getLocForEndOfToken will point to after it:
> 
> 	for(i=0; i<mand(N,N); i++) res ++;/*HERE*/
> 	(no space before the ";")
> 
> Is that the expected behaviour ? I find it pretty annoying in my very situation because I have no choice but looping with "SourceLocation::getLocWithOffset" until I find a ";".

Hm. It's expected behavior because an Expr can be nested inside other Exprs, in which case you only want the beginning and end of the Expr to include the expression itself. Consider "a + b * c;" The semicolon is not part of "b * c"; you could argue it's part of "a + b * c", but that's not consistent. On the other hand, we otherwise don't track the location of the semicolon anywhere.

I can see this being an actual deficiency we want to fix; if you're interested in pursuing this, please file a bug report at http://llvm.org/bugs/. Meanwhile, Lexer::findLocationAfterToken will probably be a more resilient way to find the semicolon.

Jordan