[Bug c++/24386] New: 4.1: wrong virtual function called in template member

[Bug c++/24386] New: 4.1: wrong virtual function called in template member

[gcc-bugzilla at gcc dot gnu dot org]

The cvs head of g++ 4.1 miscompiles the following program:

--------------------------------------------------------
extern "C" int printf(...);
struct A
{
  virtual void foo () { printf ("A::foo\n"); }
};
struct B : public A
{
  virtual void foo () { printf ("B::foo\n"); }
};

template <class T>
void f(T a)
{
  ((A*)a)->A::foo();
}

int main()
{
  f(new B);
  return 0;
}
--------------------------------------------------------

I expect this program to print `A::foo'.  But instead, it prints:

$ g++ -o x x.cc
$ ./x
B::foo
$

This worked correctly as of the cvs version from a couple weeks ago.
It also works correctly if f() is made into a non-template function.

Here is the dump of f() from the 02.original tree dump, just to verify
that the problem is upstream of here:

;; Function void f(T) [with T = B*] (_Z1fIP1BEvT_)
;; enabled by -tree-original

<<cleanup_point <<< Unknown tree: expr_stmt
  OBJ_TYPE_REF(*NON_LVALUE_EXPR <(&a->D.1746)->_vptr.A>;&a->D.1746->0)
(&a->D.1746) >>>
>>;

It's doing a virtual function call, rather than calling A::foo directly.


The problem seems to have been introduced by this change:

2005-10-12  Nathan Sidwell  <nathan@codesourcery.com>

        PR c++/21592
        * pt.c (build_non_dependent_expr): Don't wrap a COMPONENT_REF
        with already looked up member functions.  Assert we're not
        returning a NON_DEPENDENT_EXPR with unknown type.
        * typeck.c (finish_class_member_access_expr):  We can get
        non-template-id-expr baselinks.  If the lookup finds a baselink,
        remember it even inside templates.

If i revert this change, then the test case is compiled correctly.

Environment:
System: Linux karma 2.6.12.1sss #2 Thu Jul 7 00:28:21 EDT 2005 i686 i686 i386
GNU/Linux
Architecture: i686

        <machine, os, target, libraries (multiple lines)>
host: i686-pc-linux-gnu
build: i686-pc-linux-gnu
target: i686-pc-linux-gnu
configured with: /home/sss/gcc/gcc/configure --prefix=/usr/local/gcc
--enable-threads=posix --enable-long-long --enable-languages=c,c++,f95

How-To-Repeat:

See above.


-- 
           Summary: 4.1: wrong virtual function called in template member
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: snyder at fnal dot gov
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24386

[Bug c++/24386] [4.0/4.1 regression] wrong virtual function called in template member

[pinskia at gcc dot gnu dot org]

------- Comment #1 from pinskia at gcc dot gnu dot org  2005-10-15 17:47 -------
Confirmed.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |nathan at gcc dot gnu dot
                   |                            |org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
  GCC build triplet|i686-pc-linux-gnu           |
   GCC host triplet|i686-pc-linux-gnu           |
 GCC target triplet|i686-pc-linux-gnu           |
           Keywords|                            |wrong-code
      Known to fail|                            |4.0.3 4.1.0
      Known to work|                            |3.3.3 4.0.0 4.0.2
   Last reconfirmed|0000-00-00 00:00:00         |2005-10-15 17:47:15
               date|                            |
            Summary|4.1: wrong virtual function |[4.0/4.1 regression]  wrong
                   |called in template member   |virtual function called in
                   |                            |template member
   Target Milestone|---                         |4.0.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24386

[Bug c++/24386] [4.0/4.1 regression] wrong virtual function called in template member

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |critical


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24386

[Bug c++/24386] [4.0/4.1 regression] wrong virtual function called in template member

[nathan at gcc dot gnu dot org]

-- 

nathan at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |nathan at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2005-10-15 17:47:15         |2005-10-17 12:54:51
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24386

[Bug c++/24386] [4.0/4.1 regression] wrong virtual function called in template member

[cvs-commit at gcc dot gnu dot org]

------- Comment #2 from cvs-commit at gcc dot gnu dot org  2005-10-17 17:25 -------
Subject: Bug 24386

CVSROOT:        /cvs/gcc
Module name:    gcc
Changes by:     nathan@gcc.gnu.org      2005-10-17 17:25:19

Modified files:
        gcc/cp         : ChangeLog cp-tree.h pt.c typeck.c 
        gcc/testsuite  : ChangeLog 
Added files:
        gcc/testsuite/g++.dg/template: overload7.C 

Log message:
        cp:
        PR c++/24386
        * cp-tree.h (BASELINK_QUALIFIED_P): New.
        * pt.c (tsubst_copy_and_build): <CALL_EXPR case>: Use it.
        * typeck.c (finish_class_member_access_expr): Set it.
        testsuite:
        PR c++/24386
        * g++.dg/template/overload7.C: New.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/ChangeLog.diff?cvsroot=gcc&r1=1.4941&r2=1.4942
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/cp-tree.h.diff?cvsroot=gcc&r1=1.1167&r2=1.1168
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/pt.c.diff?cvsroot=gcc&r1=1.1049&r2=1.1050
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/typeck.c.diff?cvsroot=gcc&r1=1.658&r2=1.659
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.6204&r2=1.6205
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/template/overload7.C.diff?cvsroot=gcc&r1=NONE&r2=1.1


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24386

[Bug c++/24386] [4.0/4.1 regression] wrong virtual function called in template member

[nathan at gcc dot gnu dot org]

------- Comment #3 from nathan at gcc dot gnu dot org  2005-10-17 17:29 -------
2005-10-17  Nathan Sidwell  <nathan@codesourcery.com>

        PR c++/24386
        * cp-tree.h (BASELINK_QUALIFIED_P): New.
        * pt.c (tsubst_copy_and_build): <CALL_EXPR case>: Use it.
        * typeck.c (finish_class_member_access_expr): Set it.


-- 

nathan at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24386

[Bug c++/24386] [4.0/4.1 regression] wrong virtual function called in template member

[cvs-commit at gcc dot gnu dot org]

------- Comment #4 from cvs-commit at gcc dot gnu dot org  2005-10-17 17:32 -------
Subject: Bug 24386

CVSROOT:        /cvs/gcc
Module name:    gcc
Branch:         gcc-4_0-branch
Changes by:     nathan@gcc.gnu.org      2005-10-17 17:32:07

Modified files:
        gcc/cp         : ChangeLog cp-tree.h pt.c typeck.c 
        gcc/testsuite  : ChangeLog 
Added files:
        gcc/testsuite/g++.dg/template: overload7.C 

Log message:
        cp:
        PR c++/24386
        * cp-tree.h (BASELINK_QUALIFIED_P): New.
        * pt.c (tsubst_copy_and_build): <CALL_EXPR case>: Use it.
        * typeck.c (finish_class_member_access_expr): Set it.
        testsuite:
        PR c++/24386
        * g++.dg/template/overload7.C: New.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=1.4648.2.139&r2=1.4648.2.140
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/cp-tree.h.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=1.1106.2.16&r2=1.1106.2.17
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/pt.c.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=1.978.2.33&r2=1.978.2.34
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/typeck.c.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=1.616.2.21&r2=1.616.2.22
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=1.5084.2.463&r2=1.5084.2.464
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/template/overload7.C.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=NONE&r2=1.1.2.1


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24386