Dear all,
the Fortran standard requires an explicit procedure interface in certain
situations, such as when they have a BIND(C) attribute (F2018:15.4.2.2).
The attached patch adds a check for this.
Regtested on x86_64-pc-linux-gnu. OK for mainline?
The PR marks this as a long-time regression, so it might be backported
to all open branches.
Thanks,
Harald
From c48c670ff0ce4f0d2ffb1d43aca2ec1bed1fa2ef Mon Sep 17 00:00:00 2001
From: Harald Anlauf <anl...@gmx.de>
Date: Fri, 17 Mar 2023 22:24:49 +0100
Subject: [PATCH] Fortran: procedures with BIND(C) attribute require explicit
interface [PR85877]
gcc/fortran/ChangeLog:
PR fortran/85877
* resolve.cc (resolve_fl_procedure): Check for an explicit interface
of procedures with the BIND(C) attribute (F2018:15.4.2.2).
gcc/testsuite/ChangeLog:
PR fortran/85877
* gfortran.dg/pr85877.f90: New test.
---
gcc/fortran/resolve.cc | 10 ++++++++++
gcc/testsuite/gfortran.dg/pr85877.f90 | 17 +++++++++++++++++
2 files changed, 27 insertions(+)
create mode 100644 gcc/testsuite/gfortran.dg/pr85877.f90
diff --git a/gcc/fortran/resolve.cc b/gcc/fortran/resolve.cc
index 46585879ddc..7ec65f16240 100644
--- a/gcc/fortran/resolve.cc
+++ b/gcc/fortran/resolve.cc
@@ -13661,6 +13661,16 @@ check_formal:
}
}
}
+
+ /* F2018:15.4.2.2 requires an explicit interface for procedures with the
+ BIND(C) attribute. */
+ if (sym->attr.is_bind_c && sym->attr.if_source == IFSRC_UNKNOWN)
+ {
+ gfc_error ("Interface of %qs at %L must be explicit",
+ sym->name, &sym->declared_at);
+ return false;
+ }
+
return true;
}
diff --git a/gcc/testsuite/gfortran.dg/pr85877.f90 b/gcc/testsuite/gfortran.dg/pr85877.f90
new file mode 100644
index 00000000000..675faac0027
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr85877.f90
@@ -0,0 +1,17 @@
+! { dg-do compile }
+! PR fortran/85877
+! A procedure with the bind(c) attribute shall have an explicit interface
+! Contributed by G. Steinmetz
+
+subroutine p
+ bind(c) f ! { dg-error "must be explicit" }
+ x = f()
+end
+
+subroutine s
+ interface
+ function g() bind(c)
+ end function g
+ end interface
+ x = g()
+end
--
2.35.3
