Re: [C++ Patch] PR 49152

[Marc Glisse <marc dot glisse at inria dot fr>]

On Thu, 22 Mar 2012, Paolo Carlini wrote:

> Hi,
>
> On 03/22/2012 05:25 AM, Gabriel Dos Reis wrote:
> > On Wed, Mar 21, 2012 at 7:22 PM, Paolo Carlini<paolo.carlini@oracle.com> 
> > wrote:
> > > Hi,
> > >
> > > this diagnostic issue is about not even trying to print expressions in 
> > > error
> > > messages involving operators, and print operand types instead. Just as an
> > > example, for:
> > >
> > > struct X { int x; };
> > > void trigger (X x []) { x [01] = 0; }
> > >
> > > we currently print:
> > >
> > > error: no match for ‘operator=’ in ‘*(x + 4u) = 0’
> > >
> > > which the patch changes to:
> > >
> > > error: no match for ‘operator=’ (operand types are ‘X’ and ‘int’)
> > >
> > > Or, for the existing other/error10.C, from:
> > >
> > > error: no match for ‘operator-’ in ‘-(*&  a)’
> > >
> > > to
> > >
> > > error: no match for ‘operator-’ (operand type is ‘A<0>’)
> > Usually these things appear in much less simpler expressions, possibly 
> > involving
> > the same symbol but withe different meanings.  There out be the a
> > way to give an indication of which symbol the diagnostic is about.
> > Withe the (imperfect) approach of printing expressions, at least some 
> > indication
> > is given on the expression involved.  Just printing the types with no 
> > indication
> > of what expression is causing trouble is more head-scratching.
> Yes, you are right. Yesterday I had another look to the audit trail and 
> thought, mistakenly, that people had a consensus about printing the types (by 
> the way we are dealing also with much worse cases, like the one in Comment #0 
> there). Thus I don't think for the time being I can do much here, maybe the 
> PR could be even closes as duplicate of the one about missing caret.

I haven't followed the whole diagnostic discussion, but what about 
printing both the reconstructed expression and the types?

--
Marc Glisse