From 6f412a6399a7e125db835584d3d2489a52150c27 Mon Sep 17 00:00:00 2001
From: Harald Anlauf <anlauf@gmx.de>
Date: Mon, 8 Apr 2024 21:43:24 +0200
Subject: [PATCH] Fortran: fix argument checking of intrinsics C_SIZEOF,
C_F_POINTER [PR106500]
The interpretation of the F2018 standard regarding valid arguments to the
intrinsic C_SIZEOF(X) was clarified in an edit to 18-007r1:
https://j3-fortran.org/doc/year/22/22-101r1.txt
loosening restrictions and giving examples. The F2023 text has:
! F2023:18.2.3.8 C_SIZEOF (X)
!
! X shall be a data entity with interoperable type and type parameters,
! and shall not be an assumed-size array, an assumed-rank array that
! is associated with an assumed-size array, an unallocated allocatable
! variable, or a pointer that is not associated.
where
! 3.41 data entity
! data object, result of the evaluation of an expression, or the
! result of the execution of a function reference
Update the checking code for interoperable arguments accordingly, and extend
to reject functions returning pointer as FPTR argument to C_F_POINTER.
gcc/fortran/ChangeLog:
PR fortran/106500
* check.cc (is_c_interoperable): Fix checks for C_SIZEOF.
(gfc_check_c_f_pointer): Reject function returning a pointer as FPTR.
gcc/testsuite/ChangeLog:
PR fortran/106500
* gfortran.dg/c_sizeof_6.f90: Remove wrong dg-error.
* gfortran.dg/c_f_pointer_tests_9.f90: New test.
* gfortran.dg/c_sizeof_7.f90: New test.
---
gcc/fortran/check.cc | 21 ++++++----
.../gfortran.dg/c_f_pointer_tests_9.f90 | 21 ++++++++++
gcc/testsuite/gfortran.dg/c_sizeof_6.f90 | 2 +-
gcc/testsuite/gfortran.dg/c_sizeof_7.f90 | 42 +++++++++++++++++++
4 files changed, 76 insertions(+), 10 deletions(-)
create mode 100644 gcc/testsuite/gfortran.dg/c_f_pointer_tests_9.f90
create mode 100644 gcc/testsuite/gfortran.dg/c_sizeof_7.f90
@@ -5299,18 +5299,14 @@ is_c_interoperable (gfc_expr *expr, const char **msg, bool c_loc, bool c_f_ptr)
return false;
}
- if (!c_loc && expr->rank > 0 && expr->expr_type != EXPR_ARRAY)
+ /* Checks for C_SIZEOF need to take into account edits to 18-007r1, see
+ https://j3-fortran.org/doc/year/22/22-101r1.txt . */
+ if (!c_loc && !c_f_ptr && expr->rank > 0 && expr->expr_type == EXPR_VARIABLE)
{
gfc_array_ref *ar = gfc_find_array_ref (expr);
- if (ar->type != AR_FULL)
+ if (ar->type == AR_FULL && ar->as->type == AS_ASSUMED_SIZE)
{
- *msg = "Only whole-arrays are interoperable";
- return false;
- }
- if (!c_f_ptr && ar->as->type != AS_EXPLICIT
- && ar->as->type != AS_ASSUMED_SIZE)
- {
- *msg = "Only explicit-size and assumed-size arrays are interoperable";
+ *msg = "Assumed-size arrays are not interoperable";
return false;
}
}
@@ -5475,6 +5471,13 @@ gfc_check_c_f_pointer (gfc_expr *cptr, gfc_expr *fptr, gfc_expr *shape)
return false;
}
+ if (attr.function)
+ {
+ gfc_error ("FPTR at %L to C_F_POINTER is a function returning a pointer",
+ &fptr->where);
+ return false;
+ }
+
if (fptr->rank > 0 && !is_c_interoperable (fptr, &msg, false, true))
return gfc_notify_std (GFC_STD_F2018, "Noninteroperable array FPTR "
"at %L to C_F_POINTER: %s", &fptr->where, msg);
new file mode 100644
@@ -0,0 +1,21 @@
+! { dg-do compile }
+!
+! A function returning a pointer cannot be interoperable
+! and cannot be used as FPTR argument to C_F_POINTER.
+
+subroutine s ()
+ use, intrinsic :: iso_c_binding
+ implicit none
+ type(c_ptr) :: cPtr
+ call c_f_pointer (cPtr, p0) ! { dg-error "function returning a pointer" }
+ call c_f_pointer (cPtr, p1, shape=[2]) ! { dg-error "function returning a pointer" }
+contains
+ function p0 ()
+ integer, pointer :: p0
+ nullify (p0)
+ end
+ function p1 ()
+ integer, pointer :: p1(:)
+ nullify (p1)
+ end
+end
@@ -8,7 +8,7 @@ program foo
character(kind=c_char,len=1),parameter :: str2(4) = ["a","b","c","d"]
- i = c_sizeof(str2(1:3)) ! { dg-error "must be an interoperable data" }
+ i = c_sizeof(str2(1:3))
if (i /= 3) STOP 1
new file mode 100644
@@ -0,0 +1,42 @@
+! { dg-do compile }
+! PR fortran/106500 - fix checking of arguments to C_SIZEOF
+!
+! Check support of the following EDIT to 18-007r1:
+! https://j3-fortran.org/doc/year/22/22-101r1.txt
+
+subroutine foo (n, x, y, z, w, u)
+ use, intrinsic :: iso_c_binding
+ implicit none
+ integer, intent(in) :: n
+ real :: x(n)
+ real :: y(:)
+ real :: z(2,*)
+ real :: w(..)
+ real, allocatable :: a(:)
+ real, pointer :: b(:)
+ type t
+ real, allocatable :: a(:)
+ end type t
+ type(t) :: u
+
+ print *, c_sizeof (x)
+ print *, c_sizeof (x(::2))
+ print *, c_sizeof (x+1)
+ print *, c_sizeof (y)
+ print *, c_sizeof (y(1:2))
+ print *, c_sizeof (z(:,1:2))
+ print *, c_sizeof (w)
+ print *, c_sizeof (1._c_float)
+ !
+ allocate (a(n))
+ allocate (b(n))
+ if (.not. allocated (u%a)) allocate (u%a(n))
+ print *, c_sizeof (a)
+ print *, c_sizeof (b)
+ !
+ print *, c_sizeof (u%a)
+ print *, c_sizeof (u%a(1:2))
+ !
+ print *, c_sizeof (z) ! { dg-error "Assumed-size arrays are not interoperable" }
+ print *, c_sizeof (u) ! { dg-error "Expression is a noninteroperable derived type" }
+end
--
2.35.3