Re: broken FE diagnostics wrt complex expressions

[Chris Lattner <clattner at apple dot com>]

On Aug 13, 2008, at 12:16 PM, Joseph S. Myers wrote:

> On Wed, 13 Aug 2008, Aldy Hernandez wrote:
>
> > It seems to me that the only approach here would be to provide caret
> > diagnostics, because reconstructing the original sources from GENERIC
> > seems like a loosing proposition.
>
> In some cases the only useful place to find the expression is in the
> preprocessed sources, not the original sources, so you want to be  
> able to
> print an expression extracted from those not just one extracted from
> pointers into the original sources.  But in either case extracting an
> expressions using some form of beginning and ending locations would  
> give
> better results than reconstructing a representation of the  
> expression from
> trees.

I agree, this is the best way to go.  Clang produces:

$ clang t.c
t.c:4:15: error: called object is not a function or function pointer
  ({ int i; })();
  ~~~~~~~~~~~~^
t.c:13:9: error: called object is not a function or function pointer
  ((B)a)();
  ~~~~~~^
t.c:17:10: error: called object is not a function or function pointer
  (p - q)();
  ~~~~~~~^
t.c:18:18: error: called object is not a function or function pointer
  (p < q ? p : q)();
  ~~~~~~~~~~~~~~~^
4 diagnostics generated.

Which scales well to other arbitrary expressions.

-Chris