From: Tobias Burnus <tobias@codesourcery.com>
To: <fortran@gcc.gnu.org>, gcc-patches <gcc-patches@gcc.gnu.org>,
Paul-Antoine Arras <pa@codesourcery.com>
Subject: Re: [PATCH] Fortran: Fix incompatible types between INTEGER(8) and TYPE(c_ptr)
Date: Tue, 24 Oct 2023 18:12:52 +0200 [thread overview]
Message-ID: <78236b34-a5bd-4ccf-a197-94bee00b8a2b@codesourcery.com> (raw)
In-Reply-To: <6fc6a877-2dc7-4551-b141-fd117c66ecfa@codesourcery.com>
[-- Attachment #1: Type: text/plain, Size: 5596 bytes --]
Hi PA, hello all,
First, I hesitate to review/approve a patch I am involved in; Thus, I would like
if someone could have a second look.
Regarding the patch itself:
On 20.10.23 16:02, Paul-Antoine Arraswrote:
> Hi all,
>
> The attached patch fixes a bug that causes valid OpenMP declare
> variant directive
> and functions to be rejected with the following error (see testcase):
>
> [...]
> Error: variant ‘foo_variant’ and base ‘foo’ at (1) have incompatible
> types: Type mismatch in argument 'c_bv' (INTEGER(8)/TYPE(c_ptr))
>
> The fix consists in special-casing this situation in gfc_compare_types().
> OK for mainline?
...
> Subject: [PATCH] Fortran: Fix incompatible types between INTEGER(8) and
> TYPE(c_ptr)
>
> In the context of an OpenMP declare variant directive, arguments of type C_PTR
> are sometimes recognised as C_PTR in the base function and as INTEGER(8) in the
> variant - or the other way around, depending on the parsing order.
> This patch prevents such situation from turning into a compile error.
>
> 2023-10-20 Paul-Antoine Arras<pa@codesourcery.com>
> Tobias Burnus<tobias@codesourcery.com>
>
> gcc/fortran/ChangeLog:
>
> * interface.cc (gfc_compare_types): Return true in this situation.
That's a bad description. It makes sense when reading the commit log but if you
only read gcc/fortran/ChangeLog, 'this situation' is a dangling reference.
> gcc/fortran/ChangeLog.omp | 5 ++
> gcc/testsuite/ChangeLog.omp | 4 ++
On mainline, the ChangeLog not ChangeLog.omp is used. This changelog is automatically
filled by the data in the commit log. Thus, no need to include it in the patch.
(Besides: It keeps getting outdated by any other commit to that file.)
As you have a commit, running the following, possibly with the commit hash as
argument (unless it is the last commit) will show that the nightly script will use:
./contrib/gcc-changelog/git_check_commit.py -v -p
It is additionally a good check whether you got the syntax right. (This is run
as pre-commit hook.)
* * *
Regarding the patch, I think it will work, but I wonder whether we can do
better - esp. regarding c_ptr vs. c_funptr.
I started by looking why the current code fails:
> index e9843e9549c..8bd35fd6d22 100644
> --- a/gcc/fortran/interface.cc
> +++ b/gcc/fortran/interface.cc
> @@ -705,12 +705,17 @@ gfc_compare_types (gfc_typespec *ts1, gfc_typespec *ts2)
> -
> - if (((ts1->type == BT_INTEGER && ts2->type == BT_DERIVED)
> - || (ts1->type == BT_DERIVED && ts2->type == BT_INTEGER))
> - && ts1->u.derived && ts2->u.derived
> - && ts1->u.derived == ts2->u.derived)
This does not work because the pointers to the derived type are different:
(gdb) p *ts1
$10 = {type = BT_INTEGER, kind = 8, u = {derived = 0x30c66b0, cl = 0x30c66b0, pad = 51144368}, interface = 0x0, is_c_interop = 1, is_iso_c = 0, f90_type = BT_VOID, deferred = false,
interop_kind = 0x0}
(gdb) p *ts2
$11 = {type = BT_DERIVED, kind = 0, u = {derived = 0x30c2930, cl = 0x30c2930, pad = 51128624}, interface = 0x0, is_c_interop = 0, is_iso_c = 0, f90_type = BT_UNKNOWN,
deferred = false, interop_kind = 0x0}
The reason seems to be that they are freshly created
in different namespaces. Consequently, attr.use_assoc = 1
and the namespace is different, i.e.
(gdb) p ts1->u.derived->ns->proc_name->name
$18 = 0x7ffff6ff4138 "foo"
(gdb) p ts2->u.derived->ns->proc_name->name
$19 = 0x7ffff6ffc260 "foo_variant"
* * *
Having said this, I think we can combine the current
and the modified version, i.e.
> + if ((ts1->type == BT_INTEGER && ts2->type == BT_DERIVED
> + && ts1->f90_type == BT_VOID
> + && ts2->u.derived->ts.is_iso_c
> + && ts2->u.derived->ts.u.derived->ts.f90_type == BT_VOID)
> + || (ts2->type == BT_INTEGER && ts1->type == BT_DERIVED
> + && ts2->f90_type == BT_VOID
> + && ts1->u.derived->ts.is_iso_c
> + && ts1->u.derived->ts.u.derived->ts.f90_type == BT_VOID))
See attached patch for a combined version, which checks now
whether from_intmod == INTMOD_ISO_C_BINDING and then compares
the names (to distinguish c_ptr and c_funptr). Those are unaffected
by 'use' renames, hence, we should be fine.
While in this example, the name pointers are identical, I fear that
won't hold in some more complex indirect use via module-use. Thus,
strcmp is used.
(gdb) p ts1->u.derived->name
$13 = 0x7ffff6ff4100 "c_ptr"
(gdb) p ts2->u.derived->name
$14 = 0x7ffff6ff4100 "c_ptr"
* * *
Additionally, I think it would be good to have a testcase which checks for
c_funptr vs. c_ptr
mismatch.
Just changing c_ptr to c_funptr in the testcase (+ commenting the c_f_pointer)
prints:
Error: variant ‘foo_variant’ and base ‘foo’ at (1) have incompatible types: Type mismatch in argument 'c_bv' (INTEGER(8)/TYPE(c_funptr))
I think that would be a good invalid testcase besides the valid one.
But with a tweak to get better messages to give:
Error: variant ‘foo_variant’ and base ‘foo’ at (1) have incompatible types: Type mismatch in argument 'c_bv' (TYPE(c_ptr)/TYPE(c_funptr))
cf. misc.cc in the attached proposal for the *.cc files, only.
Tobias
-----------------
Siemens Electronic Design Automation GmbH; Anschrift: Arnulfstraße 201, 80634 München; Gesellschaft mit beschränkter Haftung; Geschäftsführer: Thomas Heurung, Frank Thürauf; Sitz der Gesellschaft: München; Registergericht München, HRB 106955
[-- Attachment #2: proposed.diff --]
[-- Type: text/x-patch, Size: 1937 bytes --]
gcc/fortran/interface.cc | 16 ++++++++++++----
gcc/fortran/misc.cc | 7 ++++++-
2 files changed, 18 insertions(+), 5 deletions(-)
diff --git a/gcc/fortran/interface.cc b/gcc/fortran/interface.cc
index c01df0460d7..8c4571e0aa6 100644
--- a/gcc/fortran/interface.cc
+++ b/gcc/fortran/interface.cc
@@ -736,10 +736,18 @@ gfc_compare_types (gfc_typespec *ts1, gfc_typespec *ts2)
better way of doing this. When ISO C binding is cleared up,
this can probably be removed. See PR 57048. */
- if (((ts1->type == BT_INTEGER && ts2->type == BT_DERIVED)
- || (ts1->type == BT_DERIVED && ts2->type == BT_INTEGER))
- && ts1->u.derived && ts2->u.derived
- && ts1->u.derived == ts2->u.derived)
+ if ((ts1->type == BT_INTEGER
+ && ts2->type == BT_DERIVED
+ && ts1->f90_type == BT_VOID
+ && ts2->u.derived->from_intmod == INTMOD_ISO_C_BINDING
+ && ts1->u.derived
+ && strcmp (ts1->u.derived->name, ts2->u.derived->name) == 0)
+ || (ts2->type == BT_INTEGER
+ && ts1->type == BT_DERIVED
+ && ts2->f90_type == BT_VOID
+ && ts1->u.derived->from_intmod == INTMOD_ISO_C_BINDING
+ && ts2->u.derived
+ && strcmp (ts1->u.derived->name, ts2->u.derived->name) == 0))
return true;
/* The _data component is not always present, therefore check for its
diff --git a/gcc/fortran/misc.cc b/gcc/fortran/misc.cc
index bae6d292dc5..edffba07013 100644
--- a/gcc/fortran/misc.cc
+++ b/gcc/fortran/misc.cc
@@ -138,7 +138,12 @@ gfc_typename (gfc_typespec *ts, bool for_hash)
switch (ts->type)
{
case BT_INTEGER:
- sprintf (buffer, "INTEGER(%d)", ts->kind);
+ if (ts->f90_type == BT_VOID
+ && ts->u.derived
+ && ts->u.derived->from_intmod == INTMOD_ISO_C_BINDING)
+ sprintf (buffer, "TYPE(%s)", ts->u.derived->name);
+ else
+ sprintf (buffer, "INTEGER(%d)", ts->kind);
break;
case BT_REAL:
sprintf (buffer, "REAL(%d)", ts->kind);
next prev parent reply other threads:[~2023-10-24 16:13 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-20 14:02 Paul-Antoine Arras
2023-10-24 16:12 ` Tobias Burnus [this message]
2023-10-26 11:24 ` Paul-Antoine Arras
2023-10-26 12:33 ` Tobias Burnus
2023-10-26 16:16 ` Thomas Schwinge
2023-10-26 16:28 ` Paul-Antoine Arras
2023-10-26 16:49 ` Thomas Schwinge
2023-10-26 17:00 ` tobias.burnus
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=78236b34-a5bd-4ccf-a197-94bee00b8a2b@codesourcery.com \
--to=tobias@codesourcery.com \
--cc=fortran@gcc.gnu.org \
--cc=gcc-patches@gcc.gnu.org \
--cc=pa@codesourcery.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).