[Bug c++/113454] New: [14 regression] "assignment of read-only member" error with 483.xalancbmk from SPEC CPU 2006

[Bug c++/113454] New: [14 regression] "assignment of read-only member" error with 483.xalancbmk from SPEC CPU 2006

[macro at orcam dot me.uk]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113454

            Bug ID: 113454
           Summary: [14 regression] "assignment of read-only member" error
                    with 483.xalancbmk from SPEC CPU 2006
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: macro at orcam dot me.uk
                CC: ppalka at gcc dot gnu.org
  Target Milestone: ---

Created attachment 57116
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=57116&action=edit
Reduced reproducer

As from commit 6e92a6a2a72d ("c++: non-dependent assignment checking
[PR63198, PR18474]") I get a compilation error when building 483.xalancbmk
from the SPEC CPU 2006 benchmarks suite:

./xercesc/util/NameIdPool.c: In member function
'xercesc_2_5::NameIdPoolEnumerator<TElem>&
xercesc_2_5::NameIdPoolEnumerator<TElem>::operator=(const
xercesc_2_5::NameIdPoolEnumerator<TElem>&)':
./xercesc/util/NameIdPool.c:416:20: error: assignment of read-only member
'xercesc_2_5::NameIdPoolEnumerator<TElem>::fMemoryManager'
  416 |     fMemoryManager = toAssign.fMemoryManager;
      |     ~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

For reference I have attached a reduced reproducer.  By reverting the
gcc/cp/typeck.cc part of said commit I can make this piece compile.

Now this is somewhat old code, which however used to build for at least 17
years.  Intuitively, given the `const' member annotation an assignment to
it outside a constructor is rightfully rejected, however my C++-fu is not
strong enough to back up such a claim and I can't find the relevant C++
language standard clause either way.  For several error situations we used
to accept we now provide respective `-Wno-error=' options, however this
case is not one of them.

Filing this bug then for the C++ experts to decide, and if nothing else for
posterity, so that the next person who comes across this build failure can
find it and save themselves from repeating my investigation.

[Bug c++/113454] [14 regression] "assignment of read-only member" error with 483.xalancbmk from SPEC CPU 2006

[sjames at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113454

Sam James <sjames at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |sjames at gcc dot gnu.org
         Resolution|---                         |DUPLICATE
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #1 from Sam James <sjames at gcc dot gnu.org> ---
(In reply to Maciej W. Rozycki from comment #0)
> Filing this bug then for the C++ experts to decide, and if nothing else for
> posterity, so that the next person who comes across this build failure can
> find it and save themselves from repeating my investigation.

Didn't help this time ;)

*** This bug has been marked as a duplicate of bug 111544 ***

[Bug c++/113454] [14 regression] "assignment of read-only member" error with 483.xalancbmk from SPEC CPU 2006

[macro at orcam dot me.uk]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113454

--- Comment #2 from Maciej W. Rozycki <macro at orcam dot me.uk> ---
(In reply to Sam James from comment #1)
> Didn't help this time ;)

Well, now it mentions 483.xalancbmk, which the other bug does not
(and which I searched for specifically, finding only a bunch of old
reports).