[Bug c++/60872] New: Cannot memcpy array of restricted pointers

[Bug c++/60872] New: Cannot memcpy array of restricted pointers

[e.tadeu at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60872

            Bug ID: 60872
           Summary: Cannot memcpy array of restricted pointers
           Product: gcc
           Version: 4.7.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: e.tadeu at gmail dot com

When trying to use memcpy to copy arrays of restricted pointers, it fails with
the message:


  error: '__restrict_' qualifiers cannot be applied to 'void'


This is a failing testcase:

#include <iostream>
#include <cstring>

typedef double* __restrict__ T;

void do_copy(T* a, const T* b)
{
    memcpy(a, b, sizeof(T) * 3);
}

int main()
{
    double x[3] = {1.5, 2.5, 3.5};

    double *p0[3] = {&x[2], &x[1], &x[0]};
    double *p1[3];

    do_copy(p1, p0);

    std::cout << *p1[2] << std::endl;

    return 0;
}

[Bug c++/60872] Cannot memcpy array of restricted pointers

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60872

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

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

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Reduced testcase:
typedef double * __restrict__ T;

void bar (void *);

void
foo (T *a)
{
  bar (a);
}

Whether this is valid C++ or not will leave to our C++ folks.  Not a regression
of any kind, even g++ 3.2 fails the same way.
Note that in C, you get a warning for this and with explicit cast (bar ((void
*) a);) it is accepted without diagnostics.  In C++ it errors even for that,
and for the various C++ *_cast <void *> (a).

[Bug c++/60872] Cannot memcpy array of restricted pointers

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60872

--- Comment #2 from Jason Merrill <jason at gcc dot gnu.org> ---
Author: jason
Date: Fri Apr 18 18:11:22 2014
New Revision: 209520

URL: http://gcc.gnu.org/viewcvs?rev=209520&root=gcc&view=rev
Log:
    PR c++/60872
    * call.c (standard_conversion): Don't try to apply restrict to void.

Added:
    trunk/gcc/testsuite/g++.dg/ext/restrict2.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/call.c

[Bug c++/60872] Cannot memcpy array of restricted pointers

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60872

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2014-04-19
                 CC|                            |jason at gcc dot gnu.org
           Assignee|unassigned at gcc dot gnu.org      |jason at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #3 from Jason Merrill <jason at gcc dot gnu.org> ---
Fixed on trunk so far.

[Bug c++/60872] Cannot memcpy array of restricted pointers

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60872

--- Comment #4 from Jason Merrill <jason at gcc dot gnu.org> ---
Author: jason
Date: Thu Aug  7 18:54:34 2014
New Revision: 213725

URL: https://gcc.gnu.org/viewcvs?rev=213725&root=gcc&view=rev
Log:
    PR c++/60872
    * call.c (standard_conversion): Don't try to apply restrict to void.

Added:
    branches/gcc-4_9-branch/gcc/testsuite/g++.dg/ext/restrict2.C
Modified:
    branches/gcc-4_9-branch/gcc/cp/ChangeLog
    branches/gcc-4_9-branch/gcc/cp/call.c

[Bug c++/60872] Cannot memcpy array of restricted pointers

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60872

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED
   Target Milestone|---                         |4.9.2

--- Comment #5 from Jason Merrill <jason at gcc dot gnu.org> ---
Fixed for 4.9.2.