[cfe-dev] from source location to token?

[Roberto Bagnara]

steve naroff wrote:
> Hi Paolo,
> 
> I'm not sure what you are trying to do, however here is some info...
> 
> - The AST's don't currently store Tokens (they are transient), and we  
> have no mechanism for associating an AST with a list/stream of Tokens.
> - The NamedDecl AST stores a DeclarationName (which is commonly an  
> IdentifierInfo).
> - The DeclRefExpr AST stores a NamedDecl.
> 
> You can, as you figured out, get a character stream from a  
> SourceLocation (and lex/parse again).
> 
> It would be interesting to know a little bit more about what you are  
> doing. In general, re-lexing/re-parsing isn't very desirable (though  
> it may be appropriate if it's uncommon).

Hi Steve,

there are program analyses that, for instance:

1) need to reason on an exact representation of floating-point literals
    (any approximation may result into an unsound analysis);
2) need to reason on the textual representation that was used in the
    program also for integer literals (for example, there are coding
    rules that forbid the use of octal constants: the analyzer should
    flag their use in the source program).

All the best,

    Roberto

-- 
Prof. Roberto Bagnara
Computer Science Group
Department of Mathematics, University of Parma, Italy
http://www.cs.unipr.it/~bagnara/
mailto:bagnara at cs.unipr.it