[Bug c++/36654] New: Inlined con/de-structor breaks in dllimport classes with virtual inheritance

[Bug c++/36654] New: Inlined con/de-structor breaks in dllimport classes with virtual inheritance

[tdragon at tdragon dot net]

In mingw32 builds of the GCC 4.3 branch, the following code causes an ICE:

class blah {};

class __attribute__((dllimport)) vchild : virtual public blah
{
        vchild() {}
};

The dllimport attribute, the virtual inheritance, and the inline constructor
are key to causing the error. A Windows prompt session using the MinGW GCC
4.3.0 alpha follows:

> g++ -v
Using built-in specs.
Target: mingw32
Configured with: ../gcc-4.3.0/configure
--enable-languages=c,ada,c++,fortran,java,objc,obj-c++
--disable-sjlj-exceptions --enable-shared --enable-libgcj --enable-libgomp
--with-dwarf2 --disable-win32-registry --enable-libstdcxx-debug
--enable-concept-checks --enable-version-specific-runtime-libs --build=mingw32
--with-bugurl=http://www.mingw.org/bugs.shtml --prefix=/mingw
--with-gmp=/mingw/src/gcc/gmp-mpfr-root
--with-mpfr=/mingw/src/gcc/gmp-mpfr-root
--with-libiconv-prefix=/mingw/src/gcc/libiconv-root
Thread model: win32
gcc version 4.3.0 20080305 (alpha-testing) mingw-20080502 (GCC)

> g++ -c deltatest.ii
deltatest.ii:8: internal compiler error: in maybe_emit_vtables, at
cp/decl2.c:1678
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://www.mingw.org/bugs.shtml> for instructions.


-- 
           Summary: Inlined con/de-structor breaks in dllimport classes with
                    virtual inheritance
           Product: gcc
           Version: 4.3.1
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: tdragon at tdragon dot net
 GCC build triplet: mingw32
  GCC host triplet: mingw32
GCC target triplet: mingw32


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36654

[Bug c++/36654] Inlined con/de-structor breaks virtual inheritance dllimport classes

[tdragon at tdragon dot net]

------- Comment #1 from tdragon at tdragon dot net  2008-06-27 17:09 -------
I have also discovered that this bug is *not* present in the MinGW 4.2.1 TP (or
in MinGW 3.4.5), but is present in unofficial builds of GCC 4.3.1 and 4.2.4 as
well as 4.3.0.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36654

[Bug c++/36654] Inlined con/de-structor breaks virtual inheritance dllimport classes

[dannysmith at users dot sourceforge dot net]

------- Comment #2 from dannysmith at users dot sourceforge dot net  2008-06-28 07:53 -------
This is duplicate of 35921 and is fixed on 4.3.2 and trunk. 

*** This bug has been marked as a duplicate of 35921 ***


-- 

dannysmith at users dot sourceforge dot net changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |DUPLICATE
   Target Milestone|---                         |4.3.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36654

[Bug c++/36654] Inlined con/de-structor breaks virtual inheritance dllimport classes

[tdragon at tdragon dot net]

------- Comment #3 from tdragon at tdragon dot net  2008-08-12 02:13 -------
As of r138967 pulled down today from the 4.3 branch, this bug is in fact still
present. Shell session follows.

> g++ -v
Using built-in specs.
Target: mingw32
Configured with: ../gcc-4.3-svn/configure --prefix=/mingw --build=mingw32
--enable-languages=c,c++
--with-bugurl=http://www.tdragon.net/recentgcc/bugs.php --disable-nls
--disable-win32-registry --disable-werror --enable-threads --disable-symvers
--enable-cxx-flags='-fno-function-sections -fno-data-sections'
--enable-fully-dynamic-string --enable-version-specific-runtime-libs
--enable-sjlj-exceptions --with-pkgversion='GCC TDM-1 for MinGW'
--disable-bootstrap
Thread model: win32
gcc version 4.3.2 20080811 (prerelease) (GCC TDM-1 for MinGW)

> g++ -c deltatest.ii
deltatest.ii:8: internal compiler error: in maybe_emit_vtables, at
cp/decl2.c:1745
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://www.tdragon.net/recentgcc/bugs.php> for instructions.


-- 

tdragon at tdragon dot net changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |UNCONFIRMED
         Resolution|DUPLICATE                   |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36654

[Bug c++/36654] Inlined con/de-structor breaks virtual inheritance dllimport classes

[jsm28 at gcc dot gnu dot org]

------- Comment #4 from jsm28 at gcc dot gnu dot org  2008-08-27 22:04 -------
4.3.2 is released, changing milestones to 4.3.3.


-- 

jsm28 at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.3.2                       |4.3.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36654

[Bug c++/36654] Inlined con/de-structor breaks virtual inheritance dllimport classes

[tdragon at tdragon dot net]

------- Comment #5 from tdragon at tdragon dot net  2008-09-20 17:57 -------
Any news or thoughts on this bug? (*Ping*)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36654

[Bug c++/36654] Inlined con/de-structor breaks virtual inheritance dllimport classes

[tdragon at tdragon dot net]

------- Comment #6 from tdragon at tdragon dot net  2008-10-09 22:57 -------
Ping! Any ideas on this bug?


-- 

tdragon at tdragon dot net changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|4.2.4 4.3.0 4.3.1           |4.2.4 4.3.0 4.3.1 4.3.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36654

[Bug c++/36654] [4.3 regression] Inlined con/de-structor breaks virtual inheritance dllimport classes

[tdragon at tdragon dot net]

------- Comment #7 from tdragon at tdragon dot net  2008-11-02 00:54 -------
C'mon, folks! Any chance of getting this fixed?


-- 

tdragon at tdragon dot net changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|Inlined con/de-structor     |[4.3 regression] Inlined
                   |breaks virtual inheritance  |con/de-structor breaks
                   |dllimport classes           |virtual inheritance
                   |                            |dllimport classes


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36654

[Bug c++/36654] [4.2/4.3 Regression] Inlined con/de-structor breaks virtual inheritance dllimport classes

[rguenth at gcc dot gnu dot org]

-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[4.3 regression] Inlined    |[4.2/4.3 Regression] Inlined
                   |con/de-structor breaks      |con/de-structor breaks
                   |virtual inheritance         |virtual inheritance
                   |dllimport classes           |dllimport classes
   Target Milestone|4.3.3                       |4.2.5


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36654

[Bug c++/36654] [4.2/4.3 Regression] Inlined con/de-structor breaks virtual inheritance dllimport classes

[rguenth at gcc dot gnu dot org]

-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ice-on-valid-code
           Priority|P3                          |P2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36654

[Bug c++/36654] [4.2/4.3 Regression] Inlined con/de-structor breaks virtual inheritance dllimport classes

[dannysmith at users dot sourceforge dot net]

------- Comment #8 from dannysmith at users dot sourceforge dot net  2009-01-02 04:19 -------
Hello John,
This patch:

Index: gcc/config/i386/winnt-cxx.c
===================================================================
--- gcc/config/i386/winnt-cxx.c (revision 142383)
+++ gcc/config/i386/winnt-cxx.c (working copy)
@@ -65,7 +65,7 @@
       ignore the class attribute.  */
   else if (TREE_CODE (decl) == VAR_DECL
           && TREE_STATIC (decl) && TREE_PUBLIC (decl)
-          && !DECL_EXTERNAL (decl))
+          && DECL_NOT_REALLY_EXTERN (decl))
     {
       if (!DECL_VIRTUAL_P (decl))
          error ("definition of static data member %q+D of "

fixes your testcase and causes no regressions in g++ testsuite.  I have only
tested on narrow range of dll builds, to check that the patch does not break
anything.  I think it may cause spurious errors with import of static data
members, but that can be fixed.  Could you please test with your projects.

Thanks

Danny


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36654

[Bug c++/36654] [4.2/4.3 Regression] Inlined con/de-structor breaks virtual inheritance dllimport classes

[tdragon at tdragon dot net]

------- Comment #9 from tdragon at tdragon dot net  2009-01-02 14:23 -------
That patch seems to work fine, and I haven't seen any unwarranted errors
relating to static data members so far. Thank you very much for tracking this
down!


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36654

[Bug c++/36654] [4.2/4.3 Regression] Inlined con/de-structor breaks virtual inheritance dllimport classes

[dannysmith at gcc dot gnu dot org]

------- Comment #10 from dannysmith at gcc dot gnu dot org  2009-01-07 07:33 -------
Subject: Bug 36654

Author: dannysmith
Date: Wed Jan  7 07:32:58 2009
New Revision: 143150

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=143150
Log:
        PR target/36654
        * config/i386/winnt-cxx.c (i386_pe_type_dllimport_p): Check
        DECL_NOT_REALLY_EXTERN rather than !DECL_EXTERNAL

Modified:
    branches/gcc-4_3-branch/gcc/ChangeLog
    branches/gcc-4_3-branch/gcc/config/i386/winnt-cxx.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36654

[Bug target/36654] [4.2/4.3 Regression] Inlined con/de-structor breaks virtual inheritance dllimport classes

[dannysmith at users dot sourceforge dot net]

------- Comment #11 from dannysmith at users dot sourceforge dot net  2009-01-07 07:47 -------
Fixedd on 4.3 branch


-- 

dannysmith at users dot sourceforge dot net changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|c++                         |target
      Known to work|3.4.5 4.2.1                 |3.4.5 4.2.1 4.3.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36654

[Bug target/36654] [4.2 Regression] Inlined con/de-structor breaks virtual inheritance dllimport classes

[dave dot korn dot cygwin at gmail dot com]

------- Comment #12 from dave dot korn dot cygwin at gmail dot com  2009-03-25 08:03 -------
Hi all.

This patch caused g++.dg/ext/dllimport7.C to regress (in one subtest) between
4.3.2 and 4.3.3 on Cygwin, although it could be that the testcase is out of
date.

// { dg-do compile { target i?86-*-cygwin* i?86-*-mingw*} }

//  Report errors on definition of dllimport'd static data member . 


struct Baz
{
  Baz(int a_ =0) : a(a_) {} 
  int a;
};

class  __declspec(dllimport) Bar
{
  public:
    enum {one = 1};
    static const int two = 2;
    static const int three;
    static const Baz null_baz;
};

const int Bar::three = 3;       //  { dg-warning "redeclared without dllimport"
}
//  { dg-error "definition of static data" "C++ specific error" { target
i?86-*-cygwin* i?86-*-mingw* } 21 }

const Baz Bar::null_baz;        //  { dg-warning "redeclared without dllimport"
}
//  { dg-error "definition of static data" "C++ specific error" { target
i?86-*-cygwin* i?86-*-mingw* }  24 }



int foo()
{
  Bar foobar;
  const int* baz = &Bar::two; 
  int a = foobar.two;
  int b = foobar.three;
  int c = foobar.null_baz.a;
  return (a + b + c + *baz);
}



Both the dg-error clauses now fail; previously (4.3.2), only the second one
failed.  Reverting the patch causes the first dg-error (line 21) to pass again
by restoring the error message

/gnu/gcc/release/gcc4-4.3.3-1/src/gcc-4.3.3/gcc/testsuite/g++.dg/ext/dllimport7.
C:21: error: definition of static data member 'Bar::three' of dllimport'd class

I'm not sure why that should be a problem in the first place, so I don't know
if the underlying issue is now fixed and not an error any more.  Anybody?


-- 

dave dot korn dot cygwin at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dave dot korn dot cygwin at
                   |                            |gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36654

[Bug target/36654] [4.2 Regression] Inlined con/de-structor breaks virtual inheritance dllimport classes

[dannysmith at users dot sourceforge dot net]

------- Comment #13 from dannysmith at users dot sourceforge dot net  2009-03-28 07:24 -------
(In reply to comment #12)
> Both the dg-error clauses now fail; previously (4.3.2), only the second one
> failed.  Reverting the patch causes the first dg-error (line 21) to pass again
> by restoring the error message
> 
> /gnu/gcc/release/gcc4-4.3.3-1/src/gcc-4.3.3/gcc/testsuite/g++.dg/ext/dllimport7.
> C:21: error: definition of static data member 'Bar::three' of dllimport'd class
> 
> I'm not sure why that should be a problem in the first place, so I don't know
> if the underlying issue is now fixed and not an error any more.  Anybody?
> 

IMO, the hard error should occur.
The native MS compiler emits a similar error message.
Allowing a static data member to be defined in more than one place is a bad
thing.  It most be defined in the dll if the class is defined there and, in the
situation the testcase is testing will be defined again in the exe or dll that
uses the dll.   


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36654

[Bug target/36654] [4.2 Regression] Inlined con/de-structor breaks virtual inheritance dllimport classes

[tdragon at tdragon dot net]

------- Comment #14 from tdragon at tdragon dot net  2009-03-29 15:30 -------
I have just filed PR39578, the cause of which may be related to this PR or its
fix.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36654

[Bug target/36654] [4.2 Regression] Inlined con/de-structor breaks virtual inheritance dllimport classes

[jsm28 at gcc dot gnu dot org]

------- Comment #15 from jsm28 at gcc dot gnu dot org  2009-03-31 15:42 -------
Closing 4.2 branch, fixed for 4.3.3 and 4.4.  If there are problems with
the fix, a separate issue has been / should be filed for those.


-- 

jsm28 at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
      Known to fail|4.2.4 4.3.0 4.3.1 4.3.2     |4.2.4 4.3.0 4.3.1 4.3.2
                   |                            |4.2.5
         Resolution|                            |FIXED
   Target Milestone|4.2.5                       |4.3.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36654