| Summary: | [OOP][F08] Intrinsic assign to polymorphic variable | ||
|---|---|---|---|
| Product: | gcc | Reporter: | Tobias Burnus <burnus> |
| Component: | fortran | Assignee: | Andre Vehreschild <vehre> |
| Status: | RESOLVED FIXED | ||
| Severity: | normal | CC: | abensonca, anlauf, gcc-bugs, janus, mikael, pault |
| Priority: | P3 | Keywords: | patch, rejects-valid |
| Version: | 4.5.0 | ||
| Target Milestone: | 7.0 | ||
| Host: | Target: | ||
| Build: | Known to work: | ||
| Known to fail: | Last reconfirmed: | 2010-08-03 11:23:14 | |
| Bug Depends on: | 35810, 46321 | ||
| Bug Blocks: | 39627 | ||
| Attachments: | Small patch for the resolve.c. It misses all the real work (trans*.c). | ||
|
Description
Tobias Burnus
2010-03-14 14:00:32 UTC
See "Variable must not be polymorphic in assignment" in resolve.c and note that realloc on assignment must be supported to get this working properly (might already work for derived types). (In reply to comment #1) > note that realloc on assignment must be supported to get this working properly ... which is PR35810. Test case: type :: t integer :: i end type class(t), allocatable :: x type(t) :: y = t (3) x = y print *,x%i end Here is a simple patch for getting rid of the error message:
Index: gcc/fortran/resolve.c
===================================================================
--- gcc/fortran/resolve.c (revision 169520)
+++ gcc/fortran/resolve.c (working copy)
@@ -8879,15 +8879,13 @@ resolve_ordinary_assign (gfc_code *code, gfc_names
gfc_current_ns->proc_name->attr.implicit_pure = 0;
}
- /* F03:7.4.1.2. */
- /* FIXME: Valid in Fortran 2008, unless the LHS is both polymorphic
- and coindexed; cf. F2008, 7.2.1.2 and PR 43366. */
- if (lhs->ts.type == BT_CLASS)
- {
- gfc_error ("Variable must not be polymorphic in assignment at %L",
- &lhs->where);
- return false;
- }
+ /* F03:7.4.1.2, F08:7.2.1.2. */
+ /* Valid in Fortran 2008, unless the LHS is both polymorphic and coindexed. */
+ if (lhs->ts.type == BT_CLASS
+ && gfc_notify_std (GFC_STD_F2008,
+ "Fortran 2008: Variable must not be polymorphic in "
+ "assignment at %L", &lhs->where) == FAILURE)
+ return false;
/* F2008, Section 7.2.1.2. */
if (gfc_is_coindexed (lhs) && gfc_has_ultimate_allocatable (lhs))
Realloc-on-assign for scalars was implemented in r169356. Paul, what does it take to make this work for polymorphic scalars? (In reply to comment #4) > Here is a simple patch for getting rid of the error message: The patch is not quite right. The LHS must be allocatable ("gfc_expr_attr(e).allocatable") - and it must not be coindexed ("!gfc_is_conindexed(e)"). Thus, you need something like: if (lhs->ts.type == BT_CLASS) { if (gfc_expr_attr(e).allocatable") && !gfc_is_conindexed(e)) if (gfc_notify_std(F2008 ...) == FAILURE) return false; else { gfc_error (); return false; } } (In reply to comment #4) > Here is a simple patch for getting rid of the error message: The patch is not quite right. The LHS must be allocatable and it must not be coindexed nor a coarray - otherwise, an intrinsic allocate is not allowed. Cf. "7.2.1.2 Intrinsic assignment statement": "(1) if the variable is polymorphic it shall be allocatable and not a coarray," + quote in comment 0. Thus, you need something like: if (lhs->ts.type == BT_CLASS) { if (gfc_expr_attr(e).allocatable") && !gfc_is_coindexed(e) && !gfc_expr_attr(e).codimension) { if (gfc_notify_std(F2008 ...) == FAILURE) return false; } else { gfc_error (); return false; } } (In reply to comment #6) Stupid firefox - it somehow must have submitted a draft. Ignore comment 6 and look at comment 7. (In reply to comment #5) > Realloc-on-assign for scalars was implemented in r169356. > > Paul, what does it take to make this work for polymorphic scalars? Not a lot, I think. If you take a look in gfc_trans_allocate, there is a bit that I think that you must have written, which initialises CLASS variables. I would have thought that this can be lifted and deposited wholesale in trans_assignment1 and gfc_trans_allocate reconfigured to use the assignement. I am taking a look at gfc_trans_allocate this lunchtime; there's something not quite right structurally with it. I attempted to add a patch of code to have a single evaluation of the SOURCE expression and wound up displacing unrelated declarations, when I added the se.post to the end of the main block. gimple did not like it at all :-( I'll come back to you. Cheers Paul The following patch makes the test case in comment #3 work correctly: Index: gcc/fortran/trans-expr.c =================================================================== --- gcc/fortran/trans-expr.c (revision 169986) +++ gcc/fortran/trans-expr.c (working copy) @@ -5838,6 +5838,14 @@ is_scalar_reallocatable_lhs (gfc_expr *expr) && !expr->ref) return true; + /* An allocatable class variable with no reference. */ + if (expr->symtree->n.sym->ts.type == BT_CLASS + && CLASS_DATA (expr->symtree->n.sym)->attr.allocatable + && expr->ref && expr->ref->type == REF_COMPONENT + && strcmp (expr->ref->u.c.component->name, "_data") == 0 + && expr->ref->next == NULL) + return true; + /* All that can be left are allocatable components. */ if ((expr->symtree->n.sym->ts.type != BT_DERIVED && expr->symtree->n.sym->ts.type != BT_CLASS) Index: gcc/fortran/resolve.c =================================================================== --- gcc/fortran/resolve.c (revision 169987) +++ gcc/fortran/resolve.c (working copy) @@ -8881,14 +8881,32 @@ resolve_ordinary_assign (gfc_code *code, gfc_names gfc_current_ns->proc_name->attr.implicit_pure = 0; } - /* F03:7.4.1.2. */ - /* FIXME: Valid in Fortran 2008, unless the LHS is both polymorphic - and coindexed; cf. F2008, 7.2.1.2 and PR 43366. */ if (lhs->ts.type == BT_CLASS) { - gfc_error ("Variable must not be polymorphic in assignment at %L", - &lhs->where); - return false; + /* F08:7.2.1.2. */ + if (!gfc_expr_attr (lhs).allocatable) + { + gfc_error ("Polymorphic variable in intrinsinc assignment must be " + "allocatable at %L", &lhs->where); + return false; + } + else if (gfc_expr_attr (lhs).codimension) + { + gfc_error ("Polymorphic variable in intrinsinc assignment must not be" + " coarray at %L", &lhs->where); + return false; + } + else if (gfc_is_coindexed (lhs)) + { + gfc_error ("Polymorphic variable in intrinsinc assignment must not be" + " coindexed at %L", &lhs->where); + return false; + } + /* F03:7.4.1.2. */ + else if (gfc_notify_std (GFC_STD_F2008, "Fortran 2008: Variable must not " + "be polymorphic in assignment at %L", + &lhs->where) == FAILURE) + return false; } /* F2008, Section 7.2.1.2. */ Stupid question, but shouldn't it be possible to replace the call to 'is_scalar_reallocatable_lhs' by a check for the allocatable attribute?
Index: gcc/fortran/trans-expr.c
===================================================================
--- gcc/fortran/trans-expr.c (revision 169986)
+++ gcc/fortran/trans-expr.c (working copy)
@@ -6116,8 +6087,7 @@
if (lss == gfc_ss_terminator)
{
/* F2003: Add the code for reallocation on assignment. */
- if (gfc_option.flag_realloc_lhs
- && is_scalar_reallocatable_lhs (expr1))
+ if (gfc_option.flag_realloc_lhs && gfc_expr_attr (expr1).allocatable)
alloc_scalar_allocatable_for_assignment (&block, rse.string_length,
expr1, expr2);
AFAICS, the routine does not do anything more anyway, right?
(In reply to comment #10) > The following patch makes the test case in comment #3 work correctly: I think your current patch only works if declared type (LHS) == effective type RHS. I think you need to use the size of the effective types ("_size"). The change should be in trans-expr.c's alloc_scalar_allocatable_for_assignment. Cf. "Determine allocate size" in trans-stmt.c's gfc_trans_allocate (In reply to comment #11) > Stupid question, but shouldn't it be possible to replace the call to > 'is_scalar_reallocatable_lhs' by a check for the allocatable attribute? I guess so - though I have not studied the code. Regarding the LHS (in addition to comment 6): - It may not be coindexed ("!gfc_is_conindexed(e)") - It may not be a coarray ("!gfc_expr_attr (e).codimension") - It may not have a coarray component ("!gfc_expr_attr (e).coarray_comp") Cf. F2008, 7.2.1.2, item (1) and (3). As litmus test: BT_CLASS version of PR 50981: Passing an unallocated/unassociated [or absent + nonpointer/nonallocatable] BT_CLASS variable or a unallocated/unassociated BT_CLASS component to an nonpointer/nonallocatable argument of an ELEMENTAL procedure. Created attachment 26628 [details]
Small patch for the resolve.c. It misses all the real work (trans*.c).
The following compiles with "-std=f2003" and runs successfully (using gfortran 4.8 r186145) with the "a=b" line in, but if I switch it for the "a%d=b%d" line I get a "Variable must not be polymorphic in intrinsic assignment at (1) - check that there is a matching specific subroutine for '=' operator" error: module testMod implicit none public t type t integer :: i end type t type c class(t), allocatable :: d end type c end module testMod program testProg use testMod implicit none type(t) :: f type(c) :: a,b allocate(b%d,source=f) b%d%i=12345 a=b !! THIS COMPILES OK ! a%d=b%d !! THIS DOES NOT write (0,*) a%d%i write (0,*) b%d%i end program testProg Since "d" is polymorphic both should be disallowed with "-std=f2003" (and both allowed under F2008 I think). Author: burnus Date: Wed Sep 18 18:14:57 2013 New Revision: 202713 URL: http://gcc.gnu.org/viewcvs?rev=202713&root=gcc&view=rev Log: 2013-09-15 Tobias Burnus <burnus@net-b.de> PR fortran/43366 * primary.c (gfc_variable_attr): Also handle codimension. * resolve.c (resolve_ordinary_assign): Add invalid-diagnostic * for polymorphic assignment. 2013-09-15 Tobias Burnus <burnus@net-b.de> PR fortran/43366 * gfortran.dg/class_39.f03: Update dg-error. * gfortran.dg/class_5.f03: Ditto. * gfortran.dg/class_53.f90: Ditto. * gfortran.dg/realloc_on_assign_20.f90: New. * gfortran.dg/realloc_on_assign_21.f90: New. * gfortran.dg/realloc_on_assign_22.f90: New. Added: trunk/gcc/testsuite/gfortran.dg/realloc_on_assign_20.f90 trunk/gcc/testsuite/gfortran.dg/realloc_on_assign_21.f90 trunk/gcc/testsuite/gfortran.dg/realloc_on_assign_22.f90 Modified: trunk/gcc/fortran/ChangeLog trunk/gcc/fortran/primary.c trunk/gcc/fortran/resolve.c trunk/gcc/testsuite/ChangeLog trunk/gcc/testsuite/gfortran.dg/class_39.f03 trunk/gcc/testsuite/gfortran.dg/class_5.f03 trunk/gcc/testsuite/gfortran.dg/class_53.f90 Author: vehre Date: Sat Oct 22 12:33:38 2016 New Revision: 241439 URL: https://gcc.gnu.org/viewcvs?rev=241439&root=gcc&view=rev Log: gcc/fortran/ChangeLog: 2016-10-22 Andre Vehreschild <vehre@gcc.gnu.org> PR fortran/43366 PR fortran/51864 PR fortran/57117 PR fortran/61337 PR fortran/61376 * primary.c (gfc_expr_attr): For transformational functions on classes get the attrs from the class argument. * resolve.c (resolve_ordinary_assign): Remove error message due to feature implementation. Rewrite POINTER_ASSIGNS to ordinary ones when the right-hand side is scalar class object (with some restrictions). * trans-array.c (trans_array_constructor): Create the temporary from class' inner type, i.e., the derived type. (build_class_array_ref): Add support for class array's storage of the class object or the array descriptor in the decl saved descriptor. (gfc_conv_expr_descriptor): When creating temporaries for class objects add the class object's handle into the decl saved descriptor. (structure_alloc_comps): Use the common way to get the _data component. (gfc_is_reallocatable_lhs): Add notion of allocatable class objects. * trans-expr.c (gfc_find_and_cut_at_last_class_ref): Remove the only ref only when the expression's type is BT_CLASS. (gfc_trans_class_init_assign): Correctly handle class arrays. (gfc_trans_class_assign): Joined into gfc_trans_assignment_1. (gfc_conv_procedure_call): Support for class types as arguments. (trans_get_upoly_len): For unlimited polymorphics retrieve the _len component's tree. (trans_class_vptr_len_assignment): Catch all ways to assign the _vptr and _len components of a class object correctly. (pointer_assignment_is_proc_pointer): Identify assignments of procedure pointers. (gfc_trans_pointer_assignment): Enhance support for class object pointer assignments. (gfc_trans_scalar_assign): Removed assert. (trans_class_assignment): Assign to a class object. (gfc_trans_assignment_1): Treat class objects correctly. (gfc_trans_assignment): Propagate flags to trans_assignment_1. * trans-stmt.c (gfc_trans_allocate): Use gfc_trans_assignment now instead of copy_class_to_class. * trans-stmt.h: Function prototype removed. * trans.c (trans_code): Less special casing for class objects. * trans.h: Added flags to gfc_trans_assignment () prototype. gcc/testsuite/ChangeLog: 2016-10-22 Andre Vehreschild <vehre@gcc.gnu.org> Forgot to add on original commit. * gfortran.dg/coarray_alloc_comp_2.f08: New test. 2016-10-22 Andre Vehreschild <vehre@gcc.gnu.org> PR fortran/43366 PR fortran/57117 PR fortran/61337 * gfortran.dg/alloc_comp_class_5.f03: New test. * gfortran.dg/class_allocate_21.f90: New test. * gfortran.dg/class_allocate_22.f90: New test. * gfortran.dg/realloc_on_assign_27.f08: New test. Added: trunk/gcc/testsuite/gfortran.dg/alloc_comp_class_5.f03 trunk/gcc/testsuite/gfortran.dg/class_allocate_21.f90 trunk/gcc/testsuite/gfortran.dg/class_allocate_22.f90 trunk/gcc/testsuite/gfortran.dg/coarray_alloc_comp_2.f08 trunk/gcc/testsuite/gfortran.dg/realloc_on_assign_27.f08 Modified: trunk/gcc/fortran/ChangeLog trunk/gcc/fortran/primary.c trunk/gcc/fortran/resolve.c trunk/gcc/fortran/trans-array.c trunk/gcc/fortran/trans-expr.c trunk/gcc/fortran/trans-stmt.c trunk/gcc/fortran/trans-stmt.h trunk/gcc/fortran/trans.c trunk/gcc/fortran/trans.h trunk/gcc/testsuite/ChangeLog Waiting one week for regression reports. No regressions reported so far. Closing. |