[Bug target/31488] New: va_list considered non-POD

[Bug target/31488] New: va_list considered non-POD

[rth at gcc dot gnu dot org]

.../libjava/classpath/include/jvmti.h:1242: warning: can not pass objects
of non-POD type 'struct va_list' through '...'; call will abort at runtime

Not sure yet whether this is a target problem or not.


-- 
           Summary: va_list considered non-POD
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rth at gcc dot gnu dot org
GCC target triplet: alpha*


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31488

[Bug target/31488] va_list considered non-POD

[pinskia at gcc dot gnu dot org]

------- Comment #1 from pinskia at gcc dot gnu dot org  2007-04-05 20:28 -------
Most likely this is because va_list is represented as an array for alpha and a
couple other targets.  So maybe it might be just the warning is incorrect but
it is still undefined.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31488

[Bug target/31488] va_list considered non-POD

[rth at gcc dot gnu dot org]

------- Comment #2 from rth at gcc dot gnu dot org  2007-04-05 21:45 -------
It is *not* represented as an array on Alpha.

And even if it were, it wouldn't be undefined.  Passing va_list by
value is non-portable, but certainly not undefined.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31488

[Bug target/31488] va_list considered non-POD

[ubizjak at gmail dot com]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
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------- Comment #3 from ubizjak at gmail dot com  2008-12-29 20:39 -------
The testcase:

#include <stdarg.h>

extern int foo (int a, int b, ...);

int bar (int a, int b, ...)
{
  va_list args;
  va_start (args, b);
  int result = foo (a, b, args);
  va_end (args);
  return result;
}

g++ -O2:

pod.C: In function ‘int bar(int, int, ...)’:
pod.C:9: warning: cannot pass objects of non-POD type ‘struct va_list’ through
‘...’; call will abort at runtime


-- 

ubizjak at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
OtherBugsDependingO|                            |38664
              nThis|                            |
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2008-12-29 20:39:29
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31488

[Bug target/31488] va_list considered non-POD

[ubizjak at gmail dot com]

------- Comment #4 from ubizjak at gmail dot com  2008-12-29 20:42 -------
Preprocessed source, can be compiled with a crosscompiler:

--cut here--
# 1 "pod.C"
# 1 "<built-in>"
# 1 "<command-line>"
# 1 "pod.C"
# 1 "/usr/lib/gcc/alpha-linux-gnu/4.2.4/include/stdarg.h" 1 3 4
# 43 "/usr/lib/gcc/alpha-linux-gnu/4.2.4/include/stdarg.h" 3 4
typedef __builtin_va_list __gnuc_va_list;
# 105 "/usr/lib/gcc/alpha-linux-gnu/4.2.4/include/stdarg.h" 3 4
typedef __gnuc_va_list va_list;
# 2 "pod.C" 2

extern int foo (int a, int b, ...);

int bar (int a, int b, ...)
{
  va_list args;
    __builtin_va_start(args,b);
      int result = foo (a, b, args);
        __builtin_va_end(args);
   return result;
   }
--cut here--


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31488

[Bug c++/31488] va_list considered non-POD

[pinskia at gcc dot gnu dot org]

------- Comment #5 from pinskia at gcc dot gnu dot org  2008-12-29 20:46 -------
sounds like the C++ front-end does not know this struct is a POD.  I am going
to mark this as a front-end bug.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu dot
                   |                            |org
          Component|target                      |c++
           Keywords|                            |wrong-code


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31488

[Bug c++/31488] va_list considered non-POD

[ubizjak at gmail dot com]

------- Comment #6 from ubizjak at gmail dot com  2008-12-29 20:57 -------
(In reply to comment #2)
> It is *not* represented as an array on Alpha.

But as a RECORD_TYPE. Following patch cures the warning:

Index: cp/tree.c
===================================================================
--- cp/tree.c   (revision 142948)
+++ cp/tree.c   (working copy)
@@ -2113,6 +2113,9 @@ pod_type_p (const_tree t)
      argument unmodified and we assign it to a const_tree.  */
   t = strip_array_types (CONST_CAST_TREE(t));

+  if (TREE_CODE (t) == RECORD_TYPE)
+    return 1;
+
   if (t == error_mark_node)
     return 1;
   if (INTEGRAL_TYPE_P (t))


-- 

ubizjak at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ubizjak at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31488

[Bug c++/31488] va_list considered non-POD

[pinskia at gcc dot gnu dot org]

------- Comment #7 from pinskia at gcc dot gnu dot org  2008-12-29 21:02 -------
(In reply to comment #6)
> (In reply to comment #2)
> > It is *not* represented as an array on Alpha.
> 
> But as a RECORD_TYPE. Following patch cures the warning:

But that is not correct as some nonPODs are structs too.  In fact structs
containing other nonPODs are still nonPODs.   Structs that have non trivial
constructors are also nonPODs.

So the patch is in fact incorrect.

  if (! CLASS_TYPE_P (t))
    return 0; /* other non-class type (reference or function) */
  if (CLASSTYPE_NON_POD_P (t))
    return 0;
  return 1; 

One of those two should be set correctly.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31488

[Bug c++/31488] va_list considered non-POD

[ubizjak at gmail dot com]

------- Comment #8 from ubizjak at gmail dot com  2008-12-29 23:29 -------
(In reply to comment #7)

>   if (! CLASS_TYPE_P (t))
>     return 0; /* other non-class type (reference or function) */
>   if (CLASSTYPE_NON_POD_P (t))
>     return 0;
>   return 1; 
> 
> One of those two should be set correctly.

In alpha/alpha.c we have:

alpha_build_builtin_va_list (void)
{
  tree base, ofs, space, record, type_decl;

  if (TARGET_ABI_OPEN_VMS || TARGET_ABI_UNICOSMK)
    return ptr_type_node;

  record = (*lang_hooks.types.make_type) (RECORD_TYPE);
  type_decl = build_decl (TYPE_DECL, get_identifier ("__va_list_tag"), record);
  TREE_CHAIN (record) = type_decl;
  TYPE_NAME (record) = type_decl;

  /* C++? SET_IS_AGGR_TYPE (record, 1); */

  ...

So, actually there is no way we can SET_CLASS_TYPE_P (t, 1) on the created
RECORD_TYPE. IOW, we should somehow be able to reach cp/lex.c/make_class_type
() function from target .c file.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31488

[Bug c++/31488] va_list considered non-POD

[ubizjak at gmail dot com]

------- Comment #9 from ubizjak at gmail dot com  2008-12-30 14:45 -------
Patch at http://gcc.gnu.org/ml/gcc-patches/2008-12/msg01280.html


-- 

ubizjak at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                URL|                            |http://gcc.gnu.org/ml/gcc-
                   |                            |patches/2008-
                   |                            |12/msg01280.html


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31488

[Bug c++/31488] [4.3/4.4 Regression] va_list considered non-POD

[ubizjak at gmail dot com]

------- Comment #10 from ubizjak at gmail dot com  2008-12-31 17:02 -------
Marking as a regression, testsuite failures are always regressions.


-- 

ubizjak at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|va_list considered non-POD  |[4.3/4.4 Regression] va_list
                   |                            |considered non-POD
   Target Milestone|---                         |4.3.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31488

[Bug c++/31488] [4.3/4.4 Regression] va_list considered non-POD

[rguenth at gcc dot gnu dot org]

-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31488

[Bug c++/31488] [4.3/4.4 Regression] va_list considered non-POD

[jason at gcc dot gnu dot org]

-- 

jason at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jason at gcc dot gnu dot org
         AssignedTo|unassigned at gcc dot gnu   |jason at gcc dot gnu dot org
                   |dot org                     |
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2008-12-29 20:39:29         |2009-01-05 20:01:57
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31488

[Bug c++/31488] [4.3/4.4 Regression] va_list considered non-POD

[jason at gcc dot gnu dot org]

------- Comment #11 from jason at gcc dot gnu dot org  2009-01-07 20:59 -------
Created an attachment (id=17051)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=17051&action=view)
Fix in pod_type_p

Uros is testing this patch for me.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31488

[Bug c++/31488] [4.3/4.4 Regression] va_list considered non-POD

[ubizjak at gmail dot com]

------- Comment #12 from ubizjak at gmail dot com  2009-01-08 07:04 -------
(In reply to comment #11)
> Created an attachment (id=17051)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=17051&action=view) [edit]
> Fix in pod_type_p
> 
> Uros is testing this patch for me.

This patch bootstraps OK and fixes following libjava FAILs on
alphaev56-unknown-linux-gnu:

-FAIL: natgetargssize.cc compilation
-FAIL: natgetlocalvartable.cc compilation
-FAIL: natgetstacktrace.cc compilation
-FAIL: natevents.cc compilation
-FAIL: natgetallthreads.cc compilation
-FAIL: natgeterrorname.cc compilation
-FAIL: natgetmethodname.cc compilation

The patch was also bootstrapped and regression tested on x86_64-pc-linux-gnu
{,-m32} without any problems.

BTW: Cleaned testcase can be found at [1].

[1] http://gcc.gnu.org/ml/gcc-patches/2008-12/msg01280.html


-- 

ubizjak at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                URL|http://gcc.gnu.org/ml/gcc-  |
                   |patches/2008-               |
                   |12/msg01280.html            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31488

[Bug c++/31488] [4.3/4.4 Regression] va_list considered non-POD

[jason at gcc dot gnu dot org]

------- Comment #13 from jason at gcc dot gnu dot org  2009-01-12 21:07 -------
Subject: Bug 31488

Author: jason
Date: Mon Jan 12 21:07:46 2009
New Revision: 143308

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=143308
Log:
        PR c++/31488
        * tree.c (pod_type_p): Return 1 for structs created by the back end.

Added:
    trunk/gcc/testsuite/g++.dg/other/vararg-3.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/tree.c
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31488

[Bug c++/31488] [4.3/4.4 Regression] va_list considered non-POD

[jason at gcc dot gnu dot org]

------- Comment #14 from jason at gcc dot gnu dot org  2009-01-15 22:34 -------
Subject: Bug 31488

Author: jason
Date: Thu Jan 15 22:34:20 2009
New Revision: 143413

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=143413
Log:
        PR c++/36334
        PR c++/37646
        * tree.c (lvalue_p_1): Handle BASELINK.  A COMPONENT_REF to
        a function isn't necessarily an lvalue. Take tree, not const_tree.
        (lvalue_p, real_lvalue_p): Take tree, not const_tree.
        * typeck.c (lvalue_or_else): Likewise.
        * cp-tree.h: Adjust prototypes.

        PR c++/31488
        * tree.c (pod_type_p): Return 1 for structs created by the back end.

Added:
    branches/gcc-4_3-branch/gcc/testsuite/g++.dg/conversion/memfn1.C
      - copied unchanged from r143404,
trunk/gcc/testsuite/g++.dg/conversion/memfn1.C
    branches/gcc-4_3-branch/gcc/testsuite/g++.dg/conversion/memfn2.C
      - copied unchanged from r143404,
trunk/gcc/testsuite/g++.dg/conversion/memfn2.C
    branches/gcc-4_3-branch/gcc/testsuite/g++.dg/other/vararg-3.C
      - copied unchanged from r143308,
trunk/gcc/testsuite/g++.dg/other/vararg-3.C
Modified:
    branches/gcc-4_3-branch/gcc/cp/ChangeLog
    branches/gcc-4_3-branch/gcc/cp/cp-tree.h
    branches/gcc-4_3-branch/gcc/cp/tree.c
    branches/gcc-4_3-branch/gcc/cp/typeck.c
    branches/gcc-4_3-branch/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31488

[Bug c++/31488] [4.3/4.4 Regression] va_list considered non-POD

[jason at gcc dot gnu dot org]

------- Comment #15 from jason at gcc dot gnu dot org  2009-01-15 22:54 -------
Fixed.


-- 

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=31488