Dear Fortranners,
F2008:15.3.5 relaxed the condition on interoperable character variables
and now allows values different from one. Similar text in F2018:18.3.4.
This required an adjustment in the interoperability check.
Regtested on x86_64-pc-linux-gnu. OK for mainline?
Thanks,
Harald
From 1fc44a5bf0b294021490f3c0a1539982a09000f5 Mon Sep 17 00:00:00 2001
From: Harald Anlauf <anl...@gmx.de>
Date: Fri, 12 Nov 2021 18:32:18 +0100
Subject: [PATCH] Fortran: fix interoperability check for character variables
for F2008
gcc/fortran/ChangeLog:
PR fortran/102368
* check.c (is_c_interoperable): F2008:15.3.5 relaxed the condition
on interoperable character variables and allows values different
from one.
gcc/testsuite/ChangeLog:
PR fortran/102368
* gfortran.dg/c_sizeof_7.f90: New test.
---
gcc/fortran/check.c | 20 ++++++++++++++------
gcc/testsuite/gfortran.dg/c_sizeof_7.f90 | 13 +++++++++++++
2 files changed, 27 insertions(+), 6 deletions(-)
create mode 100644 gcc/testsuite/gfortran.dg/c_sizeof_7.f90
diff --git a/gcc/fortran/check.c b/gcc/fortran/check.c
index ffa07b510cd..69a2e35e81b 100644
--- a/gcc/fortran/check.c
+++ b/gcc/fortran/check.c
@@ -5272,13 +5272,21 @@ is_c_interoperable (gfc_expr *expr, const char **msg, bool c_loc, bool c_f_ptr)
&& !gfc_simplify_expr (expr->ts.u.cl->length, 0))
gfc_internal_error ("is_c_interoperable(): gfc_simplify_expr failed");
- if (!c_loc && expr->ts.u.cl
- && (!expr->ts.u.cl->length
- || expr->ts.u.cl->length->expr_type != EXPR_CONSTANT
- || mpz_cmp_si (expr->ts.u.cl->length->value.integer, 1) != 0))
+ if (!c_loc && expr->ts.u.cl)
{
- *msg = "Type shall have a character length of 1";
- return false;
+ bool len_ok = (expr->ts.u.cl->length
+ && expr->ts.u.cl->length->expr_type == EXPR_CONSTANT);
+
+ /* F2003:15.2.1 required the length of a character variable to be one.
+ F2008:15.3.5 relaxed this to constant length. */
+ if (len_ok && !(gfc_option.allow_std & GFC_STD_F2008))
+ len_ok = mpz_cmp_si (expr->ts.u.cl->length->value.integer, 1) == 0;
+
+ if (!len_ok)
+ {
+ *msg = "Type shall have a character length of 1";
+ return false;
+ }
}
}
diff --git a/gcc/testsuite/gfortran.dg/c_sizeof_7.f90 b/gcc/testsuite/gfortran.dg/c_sizeof_7.f90
new file mode 100644
index 00000000000..3cfa3371f72
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/c_sizeof_7.f90
@@ -0,0 +1,13 @@
+! { dg-do compile }
+! { dg-options "-std=f2008 -fdump-tree-original" }
+! { dg-final { scan-tree-dump-times "_gfortran_stop_numeric" 0 "original" } }
+! PR fortran/102368
+
+program main
+ use, intrinsic :: iso_c_binding
+ implicit none
+ character(kind=c_char, len=*), parameter :: a = 'abc'
+ character(kind=c_char, len=8) :: b
+ if (c_sizeof (a) /= 3) stop 1
+ if (c_sizeof (b) /= 8) stop 2
+end program main
--
2.26.2
