| Message ID | 0281e793-09fd-b472-9392-6d2a7c26fe6c@suse.cz |
|---|---|
| State | New |
| Headers | show |
| Series | [stage1] Provide warning for missing jobserver. | expand |
> Hi. > > I'm suggesting to provide a warning when one uses -flto=jobserver > but we can't detect job server for some reason. > > Patch can bootstrap on x86_64-linux-gnu and survives regression tests. > > Ready to be installed in next stage1? > Thanks, > Martin > > gcc/ChangeLog: > > 2020-03-26 Martin Liska <mliska@suse.cz> > > PR driver/94330 > * lto-wrapper.c (run_gcc): When using -flto=jobserver, > report warning when the jobserver is not detected. This looks like a good idea to me (though I guess Richi needs to approve it). I would make message more informative so it is clear that jobserver is supposed to be provided by GNU make and that we resort to running in one thread. Morivation is that prople won't get confused trying to start GCC from other kind of build systems and also when you cut&paste the command out the warning should be explicit enough to make you notice that you can wait for very long time ;) Honza > --- > gcc/lto-wrapper.c | 12 +++++++++--- > 1 file changed, 9 insertions(+), 3 deletions(-) > > > diff --git a/gcc/lto-wrapper.c b/gcc/lto-wrapper.c > index 46a88b233f6..6263c164888 100644 > --- a/gcc/lto-wrapper.c > +++ b/gcc/lto-wrapper.c > @@ -1473,10 +1473,16 @@ run_gcc (unsigned argc, char *argv[]) > auto_parallel = 0; > parallel = 0; > } > - else if (!jobserver && jobserver_active_p ()) > + else > { > - parallel = 1; > - jobserver = 1; > + bool active_jobserver = jobserver_active_p (); > + if (jobserver && !active_jobserver) > + warning (0, "jobserver is not available."); > + else if (!jobserver && active_jobserver) > + { > + parallel = 1; > + jobserver = 1; > + } > } > > if (linker_output) >
On 3/26/20 1:42 PM, Jan Hubicka wrote: >> Hi. >> >> I'm suggesting to provide a warning when one uses -flto=jobserver >> but we can't detect job server for some reason. >> >> Patch can bootstrap on x86_64-linux-gnu and survives regression tests. >> >> Ready to be installed in next stage1? >> Thanks, >> Martin >> >> gcc/ChangeLog: >> >> 2020-03-26 Martin Liska <mliska@suse.cz> >> >> PR driver/94330 >> * lto-wrapper.c (run_gcc): When using -flto=jobserver, >> report warning when the jobserver is not detected. > This looks like a good idea to me (though I guess Richi needs to approve > it). I would make message more informative so it is clear that > jobserver is supposed to be provided by GNU make and that we resort > to running in one thread. Feel free to provide a better wording. > > Morivation is that prople won't get confused trying to start GCC from > other kind of build systems and also when you cut&paste the command out > the warning should be explicit enough to make you notice that you can > wait for very long time ;) Yes, it will be handy for these situations. If possible, I would like to see it landing in GCC 10. But it's Richi's turn. Martin > > Honza >> --- >> gcc/lto-wrapper.c | 12 +++++++++--- >> 1 file changed, 9 insertions(+), 3 deletions(-) >> >> > >> diff --git a/gcc/lto-wrapper.c b/gcc/lto-wrapper.c >> index 46a88b233f6..6263c164888 100644 >> --- a/gcc/lto-wrapper.c >> +++ b/gcc/lto-wrapper.c >> @@ -1473,10 +1473,16 @@ run_gcc (unsigned argc, char *argv[]) >> auto_parallel = 0; >> parallel = 0; >> } >> - else if (!jobserver && jobserver_active_p ()) >> + else >> { >> - parallel = 1; >> - jobserver = 1; >> + bool active_jobserver = jobserver_active_p (); >> + if (jobserver && !active_jobserver) >> + warning (0, "jobserver is not available."); >> + else if (!jobserver && active_jobserver) >> + { >> + parallel = 1; >> + jobserver = 1; >> + } >> } >> >> if (linker_output) >> >
On 3/26/20 3:40 AM, Martin Liška wrote: > Hi. > > I'm suggesting to provide a warning when one uses -flto=jobserver > but we can't detect job server for some reason. > > Patch can bootstrap on x86_64-linux-gnu and survives regression tests. > > Ready to be installed in next stage1? > Thanks, > Martin > > gcc/ChangeLog: > > 2020-03-26 Martin Liska <mliska@suse.cz> > > PR driver/94330 > * lto-wrapper.c (run_gcc): When using -flto=jobserver, > report warning when the jobserver is not detected. Sounds like a useful warning. It would be even better if it said why. jobserver_active_p() returns false under one of at least three distinct conditions. If the function provided a status string in addition to the boolean result, the string could be included in the text of the warning. As an aside, I'd expect -Wformat-diag to complain about the trailing period: + warning (0, "jobserver is not available."); Martin
On 3/29/20 12:51 AM, Martin Sebor wrote: > On 3/26/20 3:40 AM, Martin Liška wrote: >> Hi. >> >> I'm suggesting to provide a warning when one uses -flto=jobserver >> but we can't detect job server for some reason. >> >> Patch can bootstrap on x86_64-linux-gnu and survives regression tests. >> >> Ready to be installed in next stage1? >> Thanks, >> Martin >> >> gcc/ChangeLog: >> >> 2020-03-26 Martin Liska <mliska@suse.cz> >> >> PR driver/94330 >> * lto-wrapper.c (run_gcc): When using -flto=jobserver, >> report warning when the jobserver is not detected. > > Sounds like a useful warning. It would be even better if it said why. > jobserver_active_p() returns false under one of at least three distinct > conditions. If the function provided a status string in addition to > the boolean result, the string could be included in the text of > the warning. > > As an aside, I'd expect -Wformat-diag to complain about the trailing > period: > > + warning (0, "jobserver is not available."); > > Martin Hello. I like the suggested improvement, there's updated patch that I've just tested. Martin
diff --git a/gcc/lto-wrapper.c b/gcc/lto-wrapper.c index 46a88b233f6..6263c164888 100644 --- a/gcc/lto-wrapper.c +++ b/gcc/lto-wrapper.c @@ -1473,10 +1473,16 @@ run_gcc (unsigned argc, char *argv[]) auto_parallel = 0; parallel = 0; } - else if (!jobserver && jobserver_active_p ()) + else { - parallel = 1; - jobserver = 1; + bool active_jobserver = jobserver_active_p (); + if (jobserver && !active_jobserver) + warning (0, "jobserver is not available."); + else if (!jobserver && active_jobserver) + { + parallel = 1; + jobserver = 1; + } } if (linker_output)