[Bug c/94106] New: error on a function redeclaration with attribute transaction_safe

[Bug c/94106] New: error on a function redeclaration with attribute transaction_safe

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94106

            Bug ID: 94106
           Summary: error on a function redeclaration with attribute
                    transaction_safe
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: msebor at gcc dot gnu.org
  Target Milestone: ---

Of the six declarations below each is accepted on its own.  The latter two
redeclarations are accepted as well, but the first redeclaration is rejected
with an error.  I can't find documentation of the attributes in the manual so
it's not entirely clear to me whether the error is a bug or whether its absence
on the other two redeclarations is a bug, or whether this works as intended,
but intuitively I would expect all three to accepted as happens with other
attributes.

$ cat z.c && gcc -Wall -Wextra -S -Wall z.c
                                   void f0 (void);
__attribute__ ((transaction_safe)) void f0 (void);       // (bogus?) error

                                     void f1 (void);
__attribute__ ((transaction_unsafe)) void f1 (void);     // accepted

                                       void f2 (void);
__attribute__ ((transaction_callable)) void f2 (void);   // accepted

z.c:2:41: error: conflicting types for ‘f0’
    2 | __attribute__ ((transaction_safe)) void f0 (void);       // (bogus?)
error
      |                                         ^~
z.c:1:41: note: previous declaration of ‘f0’ was here
    1 |                                    void f0 (void);
      |                                         ^~

[Bug c/94106] [8/9/10 Regression] error on a function redeclaration with attribute transaction_safe

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94106

Martin Sebor <msebor at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|error on a function         |[8/9/10 Regression] error
                   |redeclaration with          |on a function redeclaration
                   |attribute transaction_safe  |with attribute
                   |                            |transaction_safe
           Keywords|                            |rejects-valid

--- Comment #1 from Martin Sebor <msebor at gcc dot gnu.org> ---
Bisection points to r228462 as the first revision to reject the code:

commit b8fd7909c04a29e82fb3ebace161801f949ad4f5
Author: Jason Merrill <jason@redhat.com>
Date:   Sun Oct 4 15:17:19 2015 -0400

    Implement N4514, C++ Extensions for Transactional Memory.

    gcc/
            * builtins.def (BUILT_IN_ABORT): Add transaction_pure attribute.
    gcc/c-family/
            * c-common.c (c_common_reswords): Add C++ TM TS keywords.
            (c_common_attribute_table): Add transaction_safe_dynamic.
            transaction_safe now affects type identity.
            (handle_tm_attribute): Handle transaction_safe_dynamic.
            * c-common.h (enum rid): Add RID_ATOMIC_NOEXCEPT,
            RID_ATOMIC_CANCEL, RID_SYNCHRONIZED.
            (OBJC_IS_CXX_KEYWORD): Add RID_SYNCHRONIZED.
            (D_TRANSMEM): New.

[Bug c/94106] [8/9/10 Regression] error on a function redeclaration with attribute transaction_safe

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94106

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |8.5

[Bug c/94106] [8/9/10 Regression] error on a function redeclaration with attribute transaction_safe

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94106

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
I'm afraid nobody really maintains the -fgnu-tm stuff anymore.

[Bug c/94106] [8/9/10 Regression] error on a function redeclaration with attribute transaction_safe

[law at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94106

Jeffrey A. Law <law at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |law at redhat dot com
           Priority|P3                          |P4

[Bug c/94106] [9/10/11/12 Regression] error on a function redeclaration with attribute transaction_safe

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94106

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|8.5                         |9.4

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 8 branch is being closed.

[Bug c/94106] [9/10/11/12 Regression] error on a function redeclaration with attribute transaction_safe

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94106

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|9.4                         |9.5

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 9.4 is being released, retargeting bugs to GCC 9.5.

[Bug c/94106] [10/11/12/13 Regression] error on a function redeclaration with attribute transaction_safe

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94106

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|9.5                         |10.4

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 9 branch is being closed

[Bug c/94106] [10/11/12/13 Regression] error on a function redeclaration with attribute transaction_safe

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94106

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|10.4                        |10.5

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 10.4 is being released, retargeting bugs to GCC 10.5.

[Bug c/94106] [11/12/13/14 Regression] error on a function redeclaration with attribute transaction_safe

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94106

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|10.5                        |11.5

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 10 branch is being closed.