[Bug c++/44282] New: GCC allows for function overloading with pointer to function as parameter based on calling convention but assembler complains

[Bug c++/44282] New: GCC allows for function overloading with pointer to function as parameter based on calling convention but assembler complains

[vadim dot atlygin at gmail dot com]

When you have function that gets pointer to a function as parameter, it is
possible to overload it based on calling convention of parameter function. But
apparently compiler generate the same signature anyway and assembler complains
about redefinition.

$ g++ test.cpp
/tmp/ccgIM8Ir.s: Assembler messages:
/tmp/ccgIM8Ir.s:103: Error: symbol `_Z1pIvEvPFT_vE' is already defined


-- 
           Summary: GCC allows for function overloading with pointer to
                    function as parameter based on calling convention but
                    assembler complains
           Product: gcc
           Version: 4.4.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: vadim dot atlygin at gmail dot com
 GCC build triplet: i486-linux-gnu
  GCC host triplet: i486-linux-gnu
GCC target triplet: i486-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44282

[Bug c++/44282] GCC allows for function overloading with pointer to function as parameter based on calling convention but assembler complains

[vadim dot atlygin at gmail dot com]

------- Comment #1 from vadim dot atlygin at gmail dot com  2010-05-26 12:59 -------
Created an attachment (id=20751)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=20751&action=view)
isolated test case


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44282

[Bug c++/44282] GCC allows for function overloading with pointer to function as parameter based on calling convention but assembler complains

[pluto at agmk dot net]

------- Comment #2 from pluto at agmk dot net  2010-05-26 17:30 -------
on gcc-4.5 we get this:

$ g++ -Wall test.cpp 
test.cpp:9:43: warning: 'fastcall' attribute ignored
test.cpp:18:45: warning: 'fastcall' attribute ignored
test.cpp:18:46: error: redefinition of 'template<class T> void p(T (*)())'
test.cpp:13:20: error: 'template<class T> void p(T (*)())' previously declared
here


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44282

[Bug c++/44282] GCC allows for function overloading with pointer to function as parameter based on calling convention but assembler complains

[vadim dot atlygin at gmail dot com]

------- Comment #3 from vadim dot atlygin at gmail dot com  2010-05-26 17:43 -------
Might be 32/64 bit difference as 64 bit platforms have only one calling
convention.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44282

[Bug c++/44282] fastcall is not mangled at all

[pinskia at gcc dot gnu dot org]

------- Comment #4 from pinskia at gcc dot gnu dot org  2010-07-24 23:17 -------
Confirmed.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
           Keywords|                            |assemble-failure
      Known to fail|                            |4.1.2 4.3.2 4.2.2 4.6.0
   Last reconfirmed|0000-00-00 00:00:00         |2010-07-24 23:17:30
               date|                            |
            Summary|GCC allows for function     |fastcall is not mangled at
                   |overloading with pointer to |all
                   |function as parameter based |
                   |on calling convention but   |
                   |assembler complains         |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44282

[Bug c++/44282] fastcall is not mangled at all

[harald at gigawatt dot nl]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44282

Harald van Dijk <harald at gigawatt dot nl> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |harald at gigawatt dot nl

--- Comment #5 from Harald van Dijk <harald at gigawatt dot nl> 2013-01-05 16:14:02 UTC ---
The description is a bit too narrow: this is not specific to fastcall, the same
problem exists with other attributes that affect the calling convention, at
least stdcall and regparm but possibly more.

[Bug c++/44282] fastcall is not mangled at all

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44282

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |741911404 at qq dot com

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
*** Bug 59158 has been marked as a duplicate of this bug. ***

[Bug c++/44282] fastcall is not mangled at all

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=44282

Jason Merrill <jason at gcc dot gnu.org> changed:

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

--- Comment #7 from Jason Merrill <jason at gcc dot gnu.org> ---
Created attachment 35417
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35417&action=edit
patch

Here's a fix.  I want to get the ABI committee to sign off on the mangling
before I check it in.

[Bug c++/44282] fastcall is not mangled at all

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=44282

--- Comment #8 from Jason Merrill <jason at gcc dot gnu.org> ---
Author: jason
Date: Tue Jun  2 02:28:19 2015
New Revision: 224007

URL: https://gcc.gnu.org/viewcvs?rev=224007&root=gcc&view=rev
Log:
        PR c++/44282
gcc/cp/
        * mangle.c (attr_strcmp): New.
        (write_CV_qualifiers_for_type): Also write out attributes that
        affect type identity.
        (write_type): Strip all attributes after writing qualifiers.
libiberty/
        * cp-demangle.c (cplus_demangle_type): Handle arguments to vendor
        extended qualifier.

Added:
    trunk/gcc/testsuite/g++.dg/abi/mangle-regparm.C
Modified:
    trunk/gcc/c-family/c-opts.c
    trunk/gcc/common.opt
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/mangle.c
    trunk/gcc/testsuite/g++.dg/abi/macro0.C
    trunk/libiberty/ChangeLog
    trunk/libiberty/cp-demangle.c
    trunk/libiberty/testsuite/demangle-expected

[Bug c++/44282] fastcall is not mangled at all

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=44282

--- Comment #9 from Jason Merrill <jason at gcc dot gnu.org> ---
Author: jason
Date: Wed Jun  3 21:09:25 2015
New Revision: 224101

URL: https://gcc.gnu.org/viewcvs?rev=224101&root=gcc&view=rev
Log:
        PR c++/44282
        * mangle.c (mangle_decl): Always SET_IDENTIFIER_GLOBAL_VALUE.
        (write_CV_qualifiers_for_type): Set G.need_abi_warning.
        (decl_implicit_alias_p): Split out from maybe_remove_implicit_alias.
        * cp-tree.h (DECL_REALLY_EXTERN): Handle null DECL_LANG_SPECIFIC.

Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/cp-tree.h
    trunk/gcc/cp/mangle.c
    trunk/gcc/testsuite/g++.dg/abi/mangle-regparm.C
    trunk/gcc/testsuite/g++.dg/abi/mangle58.C

[Bug c++/44282] fastcall is not mangled at all

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=44282

--- Comment #10 from Jason Merrill <jason at gcc dot gnu.org> ---
Author: jason
Date: Mon Sep 14 19:54:27 2015
New Revision: 227761

URL: https://gcc.gnu.org/viewcvs?rev=227761&root=gcc&view=rev
Log:
        PR c++/44282

        * mangle.c (write_CV_qualifiers_for_type): Also warn about regparm
        mangling with lower -fabi-version.

Added:
    trunk/gcc/testsuite/g++.dg/abi/mangle-regparm1a.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/mangle.c

[Bug c++/44282] fastcall is not mangled at all

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=44282

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jacek at codeweavers dot com

--- Comment #12 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
*** Bug 79582 has been marked as a duplicate of this bug. ***

[Bug c++/44282] fastcall is not mangled at all

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=44282

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ondrej.kolacek at centrum dot cz

--- Comment #13 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
*** Bug 57227 has been marked as a duplicate of this bug. ***