Re: Excluding FAILs from UNSUPPORTED test cases

Jonathan Wakely wrote:
> [...]
> Yes, this is a little surprising. If a test is UNSUPPORTED because it
> fails to match a target selector, then any dg-error or other
> directives in the test are ignored, and there are no PASS, XFAIL etc.
> lines for them in the results.
>   

If a target selector fails to match, the test is not run at all (line 
683 in current dg.exp) and the ${tool}-dg-test and ${tool}-dg-prune 
procedures are never invoked.

> But when it's unsupported because ${tool}-dg-prune returns
> "::unsupported::" the individual checks within the file still appear
> in the results. I realise that in the target selector case, the test
> is just skipped before doing anything, and in the prune case we don't
> know that it's unsupported until *after* testing it. But it seems to
> me that ideally the individual checks would get "retroactively
> skipped" if tool-dg-prune returns one of ::untested::, ::unresolved::,
> or ::unsupported::. Maybe that's not easy to do though.

This actually looks like a bug in dg.exp to me.  The output from 
${tool}-dg-test is first collected, all at once, (line 696) and then 
analyzed (lines 701-749).  I would expect ${tool}-dg-prune to have an 
opportunity to modify the text to be analyzed /before/ the analysis is 
done, but the current code checks for messages first, /then/ calls 
${tool}-dg-prune (and the framework's prune_warnings procedure) to 
remove irrelevant output, then declares excess errors if the final text 
is nonempty.

To Johnathan and Arsen:  if you agree that this seems like a bug, please 
file a report at <[email protected]> to assign a PR number to the 
issue.  If there is no good reason for the current behavior, a bug known 
to actually bite GCC is a fairly solid reason to change the code.

To Rob:  is there a good reason known for the current behavior from the 
times of old?  The code in question goes back to the "Initial revision" 
in the current repository and a quick search of the ChangeLogs sheds no 
light on the matter.


-- Jacob