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[Bug fortran/30922] New: IMPORT fails for same symbol in multiple interface bodies of same interface block
- From: "burnus at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 22 Feb 2007 09:10:23 -0000
- Subject: [Bug fortran/30922] New: IMPORT fails for same symbol in multiple interface bodies of same interface block
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
IMPORT fails, if one imports the same symbol in multiple interface bodies of
same interface block.
Found by Christopher D. Rickett,
http://gcc.gnu.org/ml/fortran/2007-02/msg00466.html
Test case:
--------------------------------------------
module test_import
implicit none
type :: my_type
integer :: data
end type my_type
interface
integer function func1(param)
import :: my_type
type(my_type) :: param
end function func1
integer function func2(param)
import :: my_type
type(my_type), value :: param
end function func2
end interface
end module test_import
--------------------------------------------
Error message:
integer function func1(param)
1
test_import.f03:4.17:
type :: my_type
2
Error: The type my_type cannot be host associated at (1) because it is
blocked by an incompatible object of the same name at (2)
Simple fix:
------------------------------
Index: resolve.c
===================================================================
--- resolve.c (revision 122189)
+++ resolve.c (working copy)
@@ -5656,7 +5656,8 @@
/* Check to see if a derived type is blocked from being host associated
by the presence of another class I symbol in the same namespace.
14.6.1.3 of the standard and the discussion on comp.lang.fortran. */
- if (sym->ts.type == BT_DERIVED && sym->ns != sym->ts.derived->ns)
+ if (sym->ts.type == BT_DERIVED && sym->ns != sym->ts.derived->ns
+ && sym->ns->proc_name->attr.if_source != IFSRC_IFBODY)
{
gfc_symbol *s;
gfc_find_symbol (sym->ts.derived->name, sym->ns, 0, &s);
------------------------------
Currently, "IMPORT :: symbol" copies the symbol like follows (simplified code;
decl.c, gfc_match_import):
-------------------
gfc_find_symbol (name, gfc_current_ns->parent, 1, &sym)
st = gfc_new_symtree (&gfc_current_ns->sym_root, name);
st->n.sym = sym;
sym->refs++;
sym->ns = gfc_current_ns;
-------------------
Possible implementation alternative, suggested by Paul Thomas,
http://gcc.gnu.org/ml/fortran/2007-02/msg00484.html
> alternatively, I have wondered for a long time if
> int ambiguous; in gfc_symtree is not out-of-order extravigant?
> A bit-field, like symbol_attribute might be very useful. Needless to say,
> imported could be added to ambiguous.
If we change the implementation, we could re-add
http://gcc.gnu.org/viewcvs/trunk/gcc/fortran/trans-decl.c?r1=119412&r2=119651&pathrev=119651&diff_format=h
cf. PR 27546.
--
Summary: IMPORT fails for same symbol in multiple interface
bodies of same interface block
Product: gcc
Version: 4.3.0
Status: UNCONFIRMED
Keywords: rejects-valid
Severity: normal
Priority: P3
Component: fortran
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: burnus at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30922