[Bug libstdc++/19510] New: [4.0 regression] Warning using list iterators

[Bug libstdc++/19510] New: [4.0 regression] Warning using list iterators

[reichelt at gcc dot gnu dot org]

Compiling the following code snippet with "-Wall -O3" using mainline

===============================================
#include<vector>
#include<list>

std::vector<std::list<int>::iterator> v(1);
===============================================

I get the following warning:

/long_path/stl_construct.h: In function 'void
__static_initialization_and_destruction_0(int, int)':
/long_path/stl_construct.h:81: warning: 'SR.133' is used uninitialized in this
function

Apart from the strange variable name 'SR.133' the warning seems to be
justified as the default constructor of _List_iterator does not initialize
the pointer _M_node. _List_const_iterator has the same problem.

The following patch fixes the problem for me.
I haven't done bootstrapping and regtesting, though.

===================================================================
--- libstdc++-v3/include/bits/stl_list.h	19 Nov 2004 12:44:09 -0000	1.45
+++ libstdc++-v3/include/bits/stl_list.h	18 Jan 2005 18:49:06 -0000
@@ -119,7 +119,8 @@ namespace _GLIBCXX_STD
       typedef _Tp*                          pointer;
       typedef _Tp&                          reference;
 
-      _List_iterator() { }
+      _List_iterator()
+      : _M_node() { }
 
       _List_iterator(_List_node_base* __x)
       : _M_node(__x) { }
@@ -195,7 +196,8 @@ namespace _GLIBCXX_STD
       typedef const _Tp*                    pointer;
       typedef const _Tp&                    reference;
 
-      _List_const_iterator() { }
+      _List_const_iterator()
+      : _M_node() { }
 
       _List_const_iterator(const _List_node_base* __x)
       : _M_node(__x) { }
===================================================================

-- 
           Summary: [4.0 regression] Warning using list iterators
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Keywords: diagnostic
          Severity: normal
          Priority: P2
         Component: libstdc++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: reichelt at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19510

[Bug libstdc++/19510] [4.0 regression] Warning using list iterators

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-01-18 20:20 -------
Confirmed, the diagnostic problem I think is already filed in a different bug.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2005-01-18 20:20:05
               date|                            |
   Target Milestone|---                         |4.0.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19510

[Bug libstdc++/19510] [4.0 regression] Warning using list iterators

[gdr at integrable-solutions dot net]

------- Additional Comments From gdr at integrable-solutions dot net  2005-01-18 21:02 -------
Subject: Re:  New: [4.0 regression] Warning using list iterators

"reichelt at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org> writes:

| Compiling the following code snippet with "-Wall -O3" using mainline
| 
| ===============================================
| #include<vector>
| #include<list>
| 
| std::vector<std::list<int>::iterator> v(1);
| ===============================================
| 
| I get the following warning:
| 
| /long_path/stl_construct.h: In function 'void
| __static_initialization_and_destruction_0(int, int)':
| /long_path/stl_construct.h:81: warning: 'SR.133' is used uninitialized in this
| function
| 
| Apart from the strange variable name 'SR.133' the warning seems to be
| justified as the default constructor of _List_iterator does not initialize
| the pointer _M_node. _List_const_iterator has the same problem.

That strange warning would be greatly useful if SRA names were not
used.  They make the diagnostic rather cryptic and noisy.

I think your patch is OK and should be applied.

-- Gaby


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19510

[Bug libstdc++/19510] [4.0 regression] Warning using list iterators

[pcarlini at suse dot de]

------- Additional Comments From pcarlini at suse dot de  2005-01-18 21:10 -------
> I think your patch is OK and should be applied.

First blush, I agree. Is it 100% safe wrt the ABI? (I remember tricky details
only about copy constructor and assignment, actually)

In case, please fix also occurrences in stl_tree.h: this issue comes from the 
original HP/SGI code...

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19510

[Bug libstdc++/19510] [4.0 regression] Warning using list iterators

[gdr at integrable-solutions dot net]

------- Additional Comments From gdr at integrable-solutions dot net  2005-01-18 21:46 -------
Subject: Re:  [4.0 regression] Warning using list iterators

"pcarlini at suse dot de" <gcc-bugzilla@gcc.gnu.org> writes:

| > I think your patch is OK and should be applied.
| 
| First blush, I agree. Is it 100% safe wrt the ABI? (I remember tricky details
| only about copy constructor and assignment, actually)

Careless addition of constructors or destructors can indeed change an ABI.

However in the specific case at hand,  the addition is that of a
non-copy default constructor whose only potential impact is that
of changing a POD to non-POD.  However, both _List_iterator and
_List_const_iterator are already non-POD as they have a constructor to
convert from a _List_node_base*.

So the patch is ABI-neutral.

-- Gaby


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19510

[Bug libstdc++/19510] [4.0 regression] Warning using list iterators

[pcarlini at suse dot de]

------- Additional Comments From pcarlini at suse dot de  2005-01-18 21:50 -------
> So the patch is ABI-neutral.

Great! (many thanks for the interesting explanation, Gaby)
Therefore, if Volker is willing to regtest the complete fix and post it...

P.S. Too bad that only -O3 triggers the warning.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19510

[Bug libstdc++/19510] [4.0 regression] Warning using list iterators

[reichelt at gcc dot gnu dot org]

------- Additional Comments From reichelt at gcc dot gnu dot org  2005-01-20 01:47 -------
Patch here:
http://gcc.gnu.org/ml/gcc-patches/2005-01/msg01280.html

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |reichelt at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED
           Keywords|                            |monitored, patch
   Last reconfirmed|2005-01-18 20:20:05         |2005-01-20 01:47:54
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19510

[Bug libstdc++/19510] [4.0 regression] Warning using list iterators

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-01-21 01:23 -------
Subject: Bug 19510

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	reichelt@gcc.gnu.org	2005-01-21 01:23:28

Modified files:
	libstdc++-v3   : ChangeLog 
	libstdc++-v3/include/bits: stl_list.h stl_tree.h 
	libstdc++-v3/testsuite/23_containers/map/operators: 1_neg.cc 
	libstdc++-v3/testsuite/23_containers/set/operators: 1_neg.cc 

Log message:
	PR libstdc++/19510
	* include/bits/stl_list.h (_List_iterator): Initialize _M_node
	in constructor.
	(_List_const_iterator): Likewise.
	* include/bits/stl_tree.h (_Rb_tree_iterator): Likewise.
	(_Rb_tree_const_iterator): Likewise.
	
	* testsuite/23_containers/map/operators/1_neg.cc: Adjust line numbers.
	* testsuite/23_containers/set/operators/1_neg.cc: Likewise.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/ChangeLog.diff?cvsroot=gcc&r1=1.2865&r2=1.2866
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/include/bits/stl_list.h.diff?cvsroot=gcc&r1=1.45&r2=1.46
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/include/bits/stl_tree.h.diff?cvsroot=gcc&r1=1.42&r2=1.43
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/testsuite/23_containers/map/operators/1_neg.cc.diff?cvsroot=gcc&r1=1.5&r2=1.6
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/testsuite/23_containers/set/operators/1_neg.cc.diff?cvsroot=gcc&r1=1.5&r2=1.6



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19510

[Bug libstdc++/19510] Uninitialized pointers in iterators

[reichelt at gcc dot gnu dot org]

------- Additional Comments From reichelt at gcc dot gnu dot org  2005-01-21 01:26 -------
We still have uninitialized pointers in the 3.4 and 3.3 branch.
Patches in preparation.


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[4.0 regression] Warning    |Uninitialized pointers in
                   |using list iterators        |iterators
   Target Milestone|4.0.0                       |3.4.4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19510

[Bug libstdc++/19510] [3.4 only] Uninitialized pointers in iterators

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-01-21 16:22 -------
Subject: Bug 19510

CVSROOT:	/cvs/gcc
Module name:	gcc
Branch: 	gcc-3_4-branch
Changes by:	reichelt@gcc.gnu.org	2005-01-21 16:21:40

Modified files:
	libstdc++-v3   : ChangeLog 
	libstdc++-v3/include/bits: stl_list.h stl_tree.h 
	libstdc++-v3/testsuite/23_containers/map/operators: 1_neg.cc 
	libstdc++-v3/testsuite/23_containers/set/operators: 1_neg.cc 

Log message:
	PR libstdc++/19510
	* include/bits/stl_list.h (_List_iterator): Initialize _M_node
	in constructor.
	(_List_const_iterator): Likewise.
	* include/bits/stl_tree.h (_Rb_tree_iterator): Likewise.
	(_Rb_tree_const_iterator): Likewise.
	
	* testsuite/23_containers/map/operators/1_neg.cc: Adjust line numbers.
	* testsuite/23_containers/set/operators/1_neg.cc: Likewise.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.2224.2.210&r2=1.2224.2.211
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/include/bits/stl_list.h.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.34.4.4&r2=1.34.4.5
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/include/bits/stl_tree.h.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.30.4.4&r2=1.30.4.5
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/testsuite/23_containers/map/operators/1_neg.cc.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.3.4.1&r2=1.3.4.2
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/testsuite/23_containers/set/operators/1_neg.cc.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.3.4.1&r2=1.3.4.2



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19510

[Bug libstdc++/19510] [3.3 only] Uninitialized pointers in iterators

[reichelt at gcc dot gnu dot org]

------- Additional Comments From reichelt at gcc dot gnu dot org  2005-01-21 16:23 -------
Regtesting patch for 3.3 branch.


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|diagnostic, monitored       |
            Summary|[3.4 only] Uninitialized    |[3.3 only] Uninitialized
                   |pointers in iterators       |pointers in iterators


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19510

[Bug libstdc++/19510] [3.3 only] Uninitialized pointers in iterators

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-01-21 23:53 -------
Subject: Bug 19510

CVSROOT:	/cvs/gcc
Module name:	gcc
Branch: 	gcc-3_3-branch
Changes by:	reichelt@gcc.gnu.org	2005-01-21 23:52:49

Modified files:
	libstdc++-v3   : ChangeLog 
	libstdc++-v3/include/bits: stl_list.h stl_tree.h 

Log message:
	PR libstdc++/19510
	* include/bits/stl_list.h (_List_iterator_base): Initialize _M_node
	in constructor.
	(_List_iterator): Initialize _List_iterator_base in constructor.
	* include/bits/stl_tree.h (_Rb_tree_iterator): Initialize _M_node
	in constructor.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_3-branch&r1=1.1464.2.194&r2=1.1464.2.195
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/include/bits/stl_list.h.diff?cvsroot=gcc&only_with_tag=gcc-3_3-branch&r1=1.20&r2=1.20.8.1
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/include/bits/stl_tree.h.diff?cvsroot=gcc&only_with_tag=gcc-3_3-branch&r1=1.17&r2=1.17.2.1



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19510

[Bug libstdc++/19510] [3.3 only] Uninitialized pointers in iterators

[reichelt at gcc dot gnu dot org]

------- Additional Comments From reichelt at gcc dot gnu dot org  2005-01-21 23:54 -------
Fixed in gcc 3.3.6, 3.4.4, and mainline.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|3.4.4                       |3.3.6


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19510