Re: relative line numbers and dg-line directive

On 05/24/2017 12:18 AM, Ben Elliston wrote:
> If we allowed multiple lines with "" as the line number, I don't think
> it should break anything in existing testsuites, would it?

I don't know the answer to that.

IIUC, you're suggesting to replace a relative line number sequence:
...
{ dg-error ... }
{ dg-error ... .-1 }
{ dg-error ... .-2 }
{ dg-error ... .-3 }
...
with:
...
{ dg-error ... }
{ dg-error ... "" }
{ dg-error ... "" }
{ dg-error ... "" }
...
or some such?

There was some discussion on this in gcc bugzilla as well, summarized in 
'PR80552 - Make consecutive relative line numbers more maintainable' 
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80552 ). Proposals in summary:

a. continue means line number of next dg-{error,warning,message,bogus} 
is same as current one:
...
   foobar; /* { dg-warning "warning for foobar" continue }
              { dg-warning "another warning for foobar" continue }
              { dg-error "error for foobar" } */
....

b. continue means line number is indicated in previous dg-{e,w,m,b}:
...
     foobar;
     /* { dg-warning "warning for foobar" .-1 }
        Bla, bla, reasoning.
        { dg-warning "another warning for foobar" continue }
        Bla, bla, more reasoning.
        { dg-error "error for foobar" continue } */
...

c. dg-{e,w,m,b} between new dg-{begin,end}-same-line-output directives 
refer to the line number indicated by dg-begin-same-line-output:
...
     foobar;
     /* { dg-begin-same-line-output .-1 }
        ...
        { dg-warning "warning for foobar" }
        ...
        { dg-message "note for foobar" }
        ...
        { dg-error "error for foobar" }
        ...
        { dg-end-same-line-output }  */
...

Thanks,
- Tom