https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99506
--- Comment #8 from Steve Kargl <sgk at troutmask dot apl.washington.edu> --- On Wed, Mar 10, 2021 at 10:59:39PM +0000, sgk at troutmask dot apl.washington.edu wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99506 > > --- Comment #7 from Steve Kargl <sgk at troutmask dot apl.washington.edu> --- > On Wed, Mar 10, 2021 at 10:22:45PM +0000, anlauf at gcc dot gnu.org wrote: > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99506 > > > > --- Comment #6 from anlauf at gcc dot gnu.org --- > > (In reply to Richard Biener from comment #4) > > > I don't know fortran enough for what 'parameter' means in this context: > > > > > > real(double), parameter:: latt(jmax) = [(latt100(i)/100.d0, j=1,jmax)] > > > > > > but the middle-end sees a readonly global (TREE_STATIC) variable. > > > > There is a possibly related issue in pr91960. > > > > Yes, same problem. An uninitialized *variable* is used in > an implied-do loop, which is an ac-value expression. Perhaps, > resolve.c(resolve_fl_parameter) needs to do some deeper > checking. > This patch fixes both 99506 and 91960. I cannot commit. Whoever decides to commit the patch needs to convert the code in 91960 into a testcase. Otherwise, this patch will fester in bugzilla with other 20 or so patches I've included in audit trails of those PRs. diff --git a/gcc/fortran/resolve.c b/gcc/fortran/resolve.c index 2a91ae743ea..84e93dbc1fd 100644 --- a/gcc/fortran/resolve.c +++ b/gcc/fortran/resolve.c @@ -15179,6 +15186,20 @@ resolve_fl_parameter (gfc_symbol *sym) return false; } + /* Some programmers can have a typo when using an implied-do loop to + initialize an array constant. For example, + INTEGER I,J + INTEGER, PARAMETER :: A(3) = [(I, I = 1, 3)] ! OK + INTEGER, PARAMETER :: B(3) = [(A(J), I = 1, 3)] ! Not OK + This check catches the typo. */ + if (sym->attr.dimension + && sym->value && sym->value->expr_type == EXPR_ARRAY + && !gfc_is_constant_expr (sym->value)) + { + gfc_error ("Expecting constant expression near %L", &sym->value->where); + return false; + } + return true; }
