| Message ID | 08a3b3f3-1803-001a-4c72-94e3baf15181@codesourcery.com |
|---|---|
| State | New |
| Headers | show |
| Series | [Fortran] PR93309 – permit repeated 'implicit none(external)' in sub-scoping unit | expand |
On 20 January 2020 15:55:23 CET, Tobias Burnus <tobias@codesourcery.com> wrote: >Using "implicit none" multiple times in a scoping unit is not permitted > >– and checked for. > >However, using one in the parent name space and re-confirming it in the > >current name space is permitted – but was before rejected. + if (sym->attr.proc == PROC_UNKNOWN) + for (gfc_namespace *ns = sym->ns; ns; ns = ns->parent) + if (ns->has_implicit_none_export) + has_implicit_none_export = true; s/;/, break;/ If we don't do this for >= -O1 already. + if (has_implicit_none_export) > >OK for the trunk? LGTM otherwise, thanks
Hi Bernhard, On 1/21/20 12:43 PM, Bernhard Reutner-Fischer wrote: > + if (sym->attr.proc == PROC_UNKNOWN) > + for (gfc_namespace *ns = sym->ns; ns; ns = ns->parent) > + if (ns->has_implicit_none_export) > + has_implicit_none_export = true; > > s/;/, break;/ > > If we don't do this for >= -O1 already. We don't. All three variants generate for -O0 to -O3 a different optimized tree. (I didn't look at RTL or assembler.) But it is also not completely clear to me which approach is the best. I think it also depends how it is converted into assembler and what the hardware actually does. I was thinking about all three variants and had settled for the shortest when sending the patch. The third variant would be: for (gfc_namespace *ns = sym->ns; ns && !has_implicit_none_export; ns = ns->parent) if (ns->has_implicit_none_export) has_implicit_none_export = true; which may or may not be faster in execution – the conditional assignment might be faster, but one has to do the "&&" operation in each step (can be AND_EXPR; it does not need to be THEN_IF_EXPR). — However, I find it less readable. At the end, it does not really matter as the loop body and expressions are small and the typical nest-depth is probably two (module + module procedures) or three (module procedures + BLOCK or host-associated procedure) such that an early abort is not really worthwhile. Even with more nesting levels, the chance that one has many sym->attr.proc == PROC_UNKNOWN in a deeply nested scoping unit should be low. (And if it is not, it will be still not the hot loop for that code.) However, I have now used the version with "break", which is also fine. r10-6108-gb31f80231df9ce6d9b50c62d28b8d2a4654ef564 Cheers, Tobias
PR fortran/93309 * interface.c (gfc_procedure_use): Also check parent namespace for 'implict none (external)'. * symbol.c (gfc_get_namespace): Don't set has_implicit_none_export to parent namespace's setting. PR fortran/93309 * gfortran.dg/external_implicit_none_2.f90: New. diff --git a/gcc/fortran/interface.c b/gcc/fortran/interface.c index c4a6882533b..5193ac4a314 100644 --- a/gcc/fortran/interface.c +++ b/gcc/fortran/interface.c @@ -3798,8 +3798,13 @@ gfc_procedure_use (gfc_symbol *sym, gfc_actual_arglist **ap, locus *where) explicitly declared at all if requested. */ if (sym->attr.if_source == IFSRC_UNKNOWN && !sym->attr.is_iso_c) { + bool has_implicit_none_export = false; implicit = true; - if (sym->ns->has_implicit_none_export && sym->attr.proc == PROC_UNKNOWN) + if (sym->attr.proc == PROC_UNKNOWN) + for (gfc_namespace *ns = sym->ns; ns; ns = ns->parent) + if (ns->has_implicit_none_export) + has_implicit_none_export = true; + if (has_implicit_none_export) { const char *guessed = gfc_lookup_function_fuzzy (sym->name, sym->ns->sym_root); diff --git a/gcc/fortran/symbol.c b/gcc/fortran/symbol.c index 526f6c466b3..47b716454f2 100644 --- a/gcc/fortran/symbol.c +++ b/gcc/fortran/symbol.c @@ -2898,9 +2898,6 @@ gfc_get_namespace (gfc_namespace *parent, int parent_types) } } - if (parent_types && ns->parent != NULL) - ns->has_implicit_none_export = ns->parent->has_implicit_none_export; - ns->refs = 1; return ns; diff --git a/gcc/testsuite/gfortran.dg/external_implicit_none_2.f90 b/gcc/testsuite/gfortran.dg/external_implicit_none_2.f90 new file mode 100644 index 00000000000..b2b1dd1e6d7 --- /dev/null +++ b/gcc/testsuite/gfortran.dg/external_implicit_none_2.f90 @@ -0,0 +1,28 @@ +! { dg-do compile } +! +! PR fortran/93309 +! +module m + implicit none(external) +contains + subroutine s + implicit none(external) ! OK + end subroutine +end module + +module m2 + implicit none(external) +contains + subroutine s + call foo(1) ! { dg-error "not explicitly declared" } + end subroutine +end module + +module m3 + implicit none(external) +contains + subroutine s + implicit none(external) ! OK + implicit none(external) ! { dg-error "Duplicate IMPLICIT NONE statement" } + end subroutine +end module