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[Patch, Fortran] PR 47474: NULL init for scalar allocatable result vars with allocatable components
- From: Tobias Burnus <burnus at net-b dot de>
- To: gcc patches <gcc-patches at gcc dot gnu dot org>, gfortran <fortran at gcc dot gnu dot org>
- Date: Wed, 26 Jan 2011 17:35:45 +0100
- Subject: [Patch, Fortran] PR 47474: NULL init for scalar allocatable result vars with allocatable components
Dear all,
functions such as
function func() result(res)
type(tx), allocatable :: res
produced code such as:
struct tx * res;
res.i.data = 0B; /*<<<< WRONG. */
res = 0B;
where the component is initialized although the pointer "res" is not
associated. If one simply swaps the "if (alloc_comp) {...} else if
(dimension == 0 && allocatable) { ... } the result is OK but there are two
res = 0B;
res = 0B;
if there is a separate result variable and one if the function name
matches the result variable; thus, I added the extra "sym ==
sym->result" check.
Note that I failed for some reason to generate a failing test case.
Thus, I did not include one. (I found the bug when trying a patch for
P4-regression PR 47455 - thus, that PR might contain a test case.)
Build and regtested on x86-64-linux.
OK for the trunk?
Tobias
2011-01-26 Tobias Burnus <burnus@net-b.de>
PR fortran/47474
* trans-decl.c (gfc_generate_function_code): Fix init
of allocatable result variable with allocatable components.
diff --git a/gcc/fortran/trans-decl.c b/gcc/fortran/trans-decl.c
index 5e3afbe..fb2f9a8 100644
--- a/gcc/fortran/trans-decl.c
+++ b/gcc/fortran/trans-decl.c
@@ -4602,16 +4716,18 @@ gfc_generate_function_code (gfc_namespace * ns)
&& sym->attr.function
&& !sym->attr.pointer)
{
- if (sym->ts.type == BT_DERIVED
- && sym->ts.u.derived->attr.alloc_comp)
+ if (sym->attr.allocatable && sym->attr.dimension == 0
+ && sym->result == sym)
+ gfc_add_modify (&init, result, fold_convert (TREE_TYPE (result),
+ null_pointer_node));
+ else if (sym->ts.type == BT_DERIVED
+ && sym->ts.u.derived->attr.alloc_comp
+ && !sym->attr.allocatable)
{
rank = sym->as ? sym->as->rank : 0;
tmp = gfc_nullify_alloc_comp (sym->ts.u.derived, result, rank);
gfc_add_expr_to_block (&init, tmp);
}
- else if (sym->attr.allocatable && sym->attr.dimension == 0)
- gfc_add_modify (&init, result, fold_convert (TREE_TYPE (result),
- null_pointer_node));
}
if (result == NULL_TREE)