| Message ID | 87d22endfn.fsf@schwinge.name |
|---|---|
| State | New |
| Headers | show |
Hi! On 06.05.2015 14:38, Thomas Schwinge wrote: > Hi! > > On Tue, 5 May 2015 15:38:03 -0400, David Malcolm <dmalcolm@redhat.com> wrote: >> On Wed, 2015-04-29 at 14:10 +0200, Mikael Morin wrote: >>> Le 29/04/2015 02:02, David Malcolm a écrit : >>>> diff --git a/gcc/fortran/parse.c b/gcc/fortran/parse.c >>>> index 2c7c554..30e4eab 100644 >>>> --- a/gcc/fortran/parse.c >>>> +++ b/gcc/fortran/parse.c >>>> @@ -4283,7 +4283,7 @@ parse_oacc_structured_block (gfc_statement acc_st) >>>> unexpected_eof (); >>>> else if (st != acc_end_st) >>>> gfc_error ("Expecting %s at %C", gfc_ascii_statement (acc_end_st)); >>>> - reject_statement (); >>>> + reject_statement (); >>>> } >>>> while (st != acc_end_st); >>>> >>> I think this one is a bug; there should be braces around 'gfc_error' and >>> 'reject_statement'. If 'st' is 'acc_end_st', as it shall be, the statement is rejected. So, this is a bug. > >>> At least that's the pattern in 'parse_oacc_loop', and how the >>> 'unexpected_statement' function is used. >> FWIW, Jeff had approved that patch, so I've committed the patch to trunk >> (as r222823), making the indentation reflect the block structure. >> >> Thomas: should the >> reject_statement (); >> call in the above be guarded by the >> else if (st != acc_end_st) >> clause? > Indeed, this seems to be a bug that has been introduced very early in the > OpenACC Fortran front end development -- see how the > parse_oacc_structured_block function evolved in the patches posted in > <http://news.gmane.org/find-root.php?message_id=%3C52E1595D.9000007%40samsung.com%3E> > and following (Ilmir, CCed "just in case"). I also see that the > corresponding OpenMP code, parse_omp_structured_block, just calls > unexpected_statement, which Ilmir's initial patch also did, but at some > point, he then changed this to the current code: gfc_error followed by > reject_statement, as cited above -- I would guess for the reason to get a > better error message? (Tobias, should this thus also be done for OpenMP, > and/or extend unexpected_statement accordingly?) That's true. I've checked abandoned openacc-1_0-branch and I used unexpected_statement there (there still odd *_acc_* naming presents instead of new-and-shiny *_oacc_* one), but, as you mentioned, I've changed this for better error reporting... and introduced the bug. > > And then, I'm a bit confused: is it "OK" that despite this presumed logic > error, which affects all (?) valid executions of this parsing code, we're > not running into any issues with the OpenACC Fortran front end test > cases? I think, this is OK, since this is an !$ACC END _smth_ statement and it shall not present in the AST. So, it is abandoned later anyway ;) (if I remember correctly, during gfc_clear_new_st call). Although the bug does not affect the logic, it is still a bug. > OK for trunk? From my point of view, OK. > > commit 068eebfa63b2b4c8849ed5fd2c9d0a130586dfb0 > Author: Thomas Schwinge <thomas@codesourcery.com> > Date: Wed May 6 13:18:18 2015 +0200 > > Fix logic error in Fortran OpenACC parsing > > gcc/fortran/ > * parse.c (parse_oacc_structured_block): Fix logic error. > Reported by Mikael Morin <mikael.morin@sfr.fr>. > --- > gcc/fortran/parse.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git gcc/fortran/parse.c gcc/fortran/parse.c > index 30e4eab..e977498 100644 > --- gcc/fortran/parse.c > +++ gcc/fortran/parse.c > @@ -4282,8 +4282,10 @@ parse_oacc_structured_block (gfc_statement acc_st) > if (st == ST_NONE) > unexpected_eof (); > else if (st != acc_end_st) > - gfc_error ("Expecting %s at %C", gfc_ascii_statement (acc_end_st)); > - reject_statement (); > + { > + gfc_error ("Expecting %s at %C", gfc_ascii_statement (acc_end_st)); > + reject_statement (); > + } > } > while (st != acc_end_st); > > > > Grüße, > Thomas
diff --git gcc/fortran/parse.c gcc/fortran/parse.c index 30e4eab..e977498 100644 --- gcc/fortran/parse.c +++ gcc/fortran/parse.c @@ -4282,8 +4282,10 @@ parse_oacc_structured_block (gfc_statement acc_st) if (st == ST_NONE) unexpected_eof (); else if (st != acc_end_st) - gfc_error ("Expecting %s at %C", gfc_ascii_statement (acc_end_st)); - reject_statement (); + { + gfc_error ("Expecting %s at %C", gfc_ascii_statement (acc_end_st)); + reject_statement (); + } } while (st != acc_end_st);