[Bug c++/32470] New: fvisibility=hidden without effect in some casses

[Bug c++/32470] New: fvisibility=hidden without effect in some casses

[gd at spherenet dot de]

Compiling the following code with fvisibility=hidden exports Test::test().
(The used compiler is 4.2.1 20070622. Version 4.2.0 on a i686 gives the same
results).

~$ cat test.cc

#include <streambuf>
class Test
{
  void test();
};
void Test::test() { }

~$ g++ -fvisibility=hidden -fPIC -c -o test.o test.cc
~$ readelf -s test.o
Symbol table '.symtab' contains 12 entries:
 Num:    Value         Size Type    Bind   Vis      Ndx Name
   0: 0000000000000000    0 NOTYPE  LOCAL  DEFAULT  UND 
   1: 0000000000000000    0 FILE    LOCAL  DEFAULT  ABS test.cc
   2: 0000000000000000    0 SECTION LOCAL  DEFAULT    1 
   3: 0000000000000000    0 SECTION LOCAL  DEFAULT    2 
   4: 0000000000000000    0 SECTION LOCAL  DEFAULT    3 
   5: 0000000000000000    0 SECTION LOCAL  DEFAULT    4 
   6: 0000000000000000    0 SECTION LOCAL  DEFAULT    6 
   7: 0000000000000000    0 SECTION LOCAL  DEFAULT    9 
   8: 0000000000000000    0 SECTION LOCAL  DEFAULT    8 
   9: 0000000000000000   10 FUNC    GLOBAL DEFAULT    1 _ZN4Test4testEv
  10: 0000000000000000    0 NOTYPE  GLOBAL DEFAULT  UND __gxx_personality_v0
  11: 0000000000000000    8 OBJECT  WEAK   HIDDEN    6
DW.ref.__gxx_personality_

After removing #include <streambuf> from the testcase, Test::test() is hidden
as expected.

~$ g++ -fvisibility=hidden -fPIC -c -o test.o test.cc
~$ readelf -s test.o
Symbol table '.symtab' contains 12 entries:
 Num:    Value         Size Type    Bind   Vis      Ndx Name
   0: 0000000000000000    0 NOTYPE  LOCAL  DEFAULT  UND 
   1: 0000000000000000    0 FILE    LOCAL  DEFAULT  ABS test.cc
   2: 0000000000000000    0 SECTION LOCAL  DEFAULT    1 
   3: 0000000000000000    0 SECTION LOCAL  DEFAULT    2 
   4: 0000000000000000    0 SECTION LOCAL  DEFAULT    3 
   5: 0000000000000000    0 SECTION LOCAL  DEFAULT    4 
   6: 0000000000000000    0 SECTION LOCAL  DEFAULT    6 
   7: 0000000000000000    0 SECTION LOCAL  DEFAULT    9 
   8: 0000000000000000    0 SECTION LOCAL  DEFAULT    8 
   9: 0000000000000000   10 FUNC    GLOBAL HIDDEN    1 _ZN4Test4testEv
  10: 0000000000000000    0 NOTYPE  GLOBAL DEFAULT  UND __gxx_personality_v0
  11: 0000000000000000    8 OBJECT  WEAK   HIDDEN    6
DW.ref.__gxx_personality_


-- 
           Summary: fvisibility=hidden without effect in some casses
           Product: gcc
           Version: 4.2.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: gd at spherenet dot de
 GCC build triplet: x86_64-unknown-linux-gnu
  GCC host triplet: x86_64-unknown-linux-gnu
GCC target triplet: x86_64-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32470

[Bug c++/32470] fvisibility=hidden without effect in some casses

[pinskia at gcc dot gnu dot org]

------- Comment #1 from pinskia at gcc dot gnu dot org  2007-06-24 00:53 -------
I can reproduce this, I am in the middle of reducing it, it is an interaction
between friends, extern templates and visibility attribute on namespaces.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32470

[Bug c++/32470] fvisibility=hidden without effect in some casses

[gd at spherenet dot de]

------- Comment #2 from gd at spherenet dot de  2007-06-25 23:38 -------
Here is the reduced testcase which shows the bug:
=============
namespace std __attribute__((__visibility__("default"))) {
  template<typename _CharT>
  class basic_streambuf
  {
    friend void getline();
  };
  extern template class basic_streambuf<char>;
}

class Test
{
  void test();
};
void Test::test() { }
==============
The extern declaration triggers instantiate_class_template (pt.c) before the
scope of the namespace is left and its visibility popped. While handling the
friend declaration, we push into the namespace's scope a second time which
clears its has_visibility flag. Hence, the visibility is not popped when we
finally leave the namespace.

What about the following patch proposal:
        * cp/name-lookup.c (push_namespace_with_attribs) Do not clear the
        has_visibility flag when entering a namespace's scope, ...
        (leave_scope) ... but when leaving

--- gcc-4_2-branch/gcc/cp/name-lookup.c (revision 126002)
+++ gcc-4_2-branch/gcc/cp/name-lookup.c (working copy)
@@ -1350,7 +1350,12 @@

 #ifdef HANDLE_PRAGMA_VISIBILITY
   if (scope->has_visibility)
-    pop_visibility ();
+    {
+      pop_visibility ();
+      /* Clear has_visibility in case the next namespace-definition has
+         no visibility attribute. */
+      scope->has_visibility = 0;
+    }
 #endif

   /* Move one nesting level up.  */
@@ -3067,9 +3072,6 @@
   current_namespace = d;

 #ifdef HANDLE_PRAGMA_VISIBILITY
-  /* Clear has_visibility in case a previous namespace-definition had a
-     visibility attribute and this one doesn't.  */
-  current_binding_level->has_visibility = 0;
   for (d = attributes; d; d = TREE_CHAIN (d))
     {
       tree name = TREE_PURPOSE (d);


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32470

[Bug c++/32470] fvisibility=hidden without effect in some cases

[gd at spherenet dot de]

------- Comment #3 from gd at spherenet dot de  2007-07-02 15:01 -------
Ping.
Is there any reason why this one is still unconfirmed? It could be reproduced
by Andrew.


-- 

gd at spherenet dot de changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|fvisibility=hidden without  |fvisibility=hidden without
                   |effect in some casses       |effect in some cases


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32470

[Bug c++/32470] fvisibility=hidden without effect in some cases

[mueller at gcc dot gnu dot org]

------- Comment #4 from mueller at gcc dot gnu dot org  2007-09-11 22:37 -------
I can confirm it as well


-- 

mueller at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2007-09-11 22:37:55
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32470

[Bug c++/32470] [4.2 regression] fvisibility=hidden without effect in some cases

[mueller at gcc dot gnu dot org]

------- Comment #5 from mueller at gcc dot gnu dot org  2007-09-11 22:39 -------
*** Bug 33399 has been marked as a duplicate of this bug. ***


-- 

mueller at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |mueller at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32470

[Bug c++/32470] [4.2/4.3 regression] fvisibility=hidden without effect in some cases

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[4.2 regression]            |[4.2/4.3 regression]
                   |fvisibility=hidden without  |fvisibility=hidden without
                   |effect in some cases        |effect in some cases
   Target Milestone|---                         |4.2.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32470

[Bug c++/32470] [4.2/4.3 regression] fvisibility=hidden without effect in some cases

[mmitchel at gcc dot gnu dot org]

------- Comment #6 from mmitchel at gcc dot gnu dot org  2007-09-28 03:55 -------
Andrew, thanks for the analysis.  But, I'm not very happy with the patch.  Can
we change the compiler so that we set has_visibility on a binding level when
the binding level is created -- and never reset it, ever? 


-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |wrong-code
           Priority|P3                          |P1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32470

[Bug c++/32470] [4.2/4.3 regression] fvisibility=hidden without effect in some cases

[gd at spherenet dot de]

------- Comment #7 from gd at spherenet dot de  2007-10-01 14:42 -------
Just to be sure I understood everything correctly. Assume the following code:
namespace foo __attribute__((__visibility__("default"))) {
   ...
}
namespace foo {
   ...
}
The same binding level is used for both namespace definitions, but visibility
is pushed/popped only when entering/leaving the scope of the first definition.
The only purpose of has_visibility is to indicate that visibility was pushed
for the current namespace definition and needs to be popped when leaving. Yes?
Then we have to reset the has_visibility flag (or drop the flag and find
another way to signal that visibility needs to be popped).


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32470

[Bug c++/32470] [4.2/4.3 regression] fvisibility=hidden without effect in some cases

[jason at gcc dot gnu dot org]

-- 

jason at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |jason at gcc dot gnu dot org
                   |dot org                     |
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2007-09-11 22:37:55         |2007-10-04 01:30:50
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32470

[Bug c++/32470] [4.2/4.3 regression] fvisibility=hidden without effect in some cases

[jason at gcc dot gnu dot org]

------- Comment #8 from jason at gcc dot gnu dot org  2007-10-04 08:48 -------
Subject: Bug 32470

Author: jason
Date: Thu Oct  4 08:48:23 2007
New Revision: 129003

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=129003
Log:
        PR c++/32470
        * name-lookup.c (push_namespace_with_attrs): Fold back into...
        (push_namespace): Here.
        (handle_namespace_attrs): New fn for the attr code.
        (leave_scope): Don't pop_visibility.
        * name-lookup.h (struct cp_binding_level): Remove has_visibility.
        * parser.c (cp_parser_namespace_definition): Call
        handle_namespace_attrs and pop_visibility as appropriate.

Added:
    trunk/gcc/testsuite/g++.dg/ext/visibility/namespace2.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/name-lookup.c
    trunk/gcc/cp/name-lookup.h
    trunk/gcc/cp/parser.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32470

[Bug c++/32470] [4.2 regression] fvisibility=hidden without effect in some cases

[jason at gcc dot gnu dot org]

------- Comment #9 from jason at gcc dot gnu dot org  2007-10-04 08:50 -------
Fixed for 4.3.0.


-- 

jason at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|4.1.2                       |4.1.2 4.3.0
            Summary|[4.2/4.3 regression]        |[4.2 regression]
                   |fvisibility=hidden without  |fvisibility=hidden without
                   |effect in some cases        |effect in some cases


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32470

[Bug c++/32470] [4.2 regression] fvisibility=hidden without effect in some cases

[mmitchel at gcc dot gnu dot org]

------- Comment #10 from mmitchel at gcc dot gnu dot org  2007-10-09 19:20 -------
Change target milestone to 4.2.3, as 4.2.2 has been released.


-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.2.2                       |4.2.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32470

[Bug c++/32470] [4.2 regression] fvisibility=hidden without effect in some cases

[jason at gcc dot gnu dot org]

------- Comment #11 from jason at gcc dot gnu dot org  2007-10-09 20:52 -------
Subject: Bug 32470

Author: jason
Date: Tue Oct  9 20:52:24 2007
New Revision: 129180

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=129180
Log:
        PR c++/32470
        * name-lookup.c (push_namespace_with_attrs): Fold back into...
        (push_namespace): Here.
        (handle_namespace_attrs): New fn for the attr code.
        (leave_scope): Don't pop_visibility.
        * name-lookup.h (struct cp_binding_level): Remove has_visibility.
        * parser.c (cp_parser_namespace_definition): Call
        handle_namespace_attrs and pop_visibility as appropriate.

        PR c++/33094
        * decl.c (make_rtl_for_nonlocal_decl): It's ok for a member
        constant to not have DECL_EXTERNAL if it's file-local.

Added:
    branches/gcc-4_2-branch/gcc/testsuite/g++.dg/ext/visibility/anon6.C
      - copied unchanged from r128890,
trunk/gcc/testsuite/g++.dg/ext/visibility/anon6.C
    branches/gcc-4_2-branch/gcc/testsuite/g++.dg/ext/visibility/namespace2.C
      - copied unchanged from r129003,
trunk/gcc/testsuite/g++.dg/ext/visibility/namespace2.C
Modified:
    branches/gcc-4_2-branch/gcc/cp/ChangeLog
    branches/gcc-4_2-branch/gcc/cp/decl.c
    branches/gcc-4_2-branch/gcc/cp/name-lookup.c
    branches/gcc-4_2-branch/gcc/cp/name-lookup.h
    branches/gcc-4_2-branch/gcc/cp/parser.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32470

[Bug c++/32470] [4.2 regression] fvisibility=hidden without effect in some cases

[jason at gcc dot gnu dot org]

------- Comment #12 from jason at gcc dot gnu dot org  2007-10-09 21:10 -------
Fixed for 4.2.3.


-- 

jason at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32470

[Bug c++/32470] [4.2 regression] fvisibility=hidden without effect in some cases

[jason at gcc dot gnu dot org]

------- Comment #13 from jason at gcc dot gnu dot org  2007-10-22 18:12 -------
Subject: Bug 32470

Author: jason
Date: Mon Oct 22 18:12:36 2007
New Revision: 129554

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=129554
Log:
        PR c++/32470
        * name-lookup.c (push_namespace_with_attrs): Fold back into...
        (push_namespace): Here.
        (handle_namespace_attrs): New fn for the attr code.
        (leave_scope): Don't pop_visibility.
        * name-lookup.h (struct cp_binding_level): Remove has_visibility.
        * parser.c (cp_parser_namespace_definition): Call
        handle_namespace_attrs and pop_visibility as appropriate.

        PR c++/33094
        * decl.c (make_rtl_for_nonlocal_decl): It's ok for a member
        constant to not have DECL_EXTERNAL if it's file-local.

        * decl2.c (get_guard): Copy visibility from the guarded variable.

        PR c++/29365
        * pt.c (outermost_tinst_level): New function.
        * lex.c (in_main_input_context): New function.
        * decl2.c (constrain_class_visibility): Use it to avoid warning
        about uses of the anonymous namespace in the main input file.

Modified:
    branches/redhat/gcc-4_1-branch/gcc/cp/ChangeLog
    branches/redhat/gcc-4_1-branch/gcc/cp/cp-tree.h
    branches/redhat/gcc-4_1-branch/gcc/cp/decl.c
    branches/redhat/gcc-4_1-branch/gcc/cp/decl2.c
    branches/redhat/gcc-4_1-branch/gcc/cp/lex.c
    branches/redhat/gcc-4_1-branch/gcc/cp/name-lookup.c
    branches/redhat/gcc-4_1-branch/gcc/cp/name-lookup.h
    branches/redhat/gcc-4_1-branch/gcc/cp/parser.c
    branches/redhat/gcc-4_1-branch/gcc/cp/pt.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32470