gdb cannot understand some type with STL

gdb cannot understand some type with STL

[jian shen]

Hi

gdb version: 6.6
gcc version: 3.3.6
qt version: 3.1

Everything is correct when I use qt container:
testcase 1:

----- qt.cpp -----
#include <qstring.h>
#include <qmap.h>
#include <qvaluelist.h>

int main()
{
  QValueList<int> l;
  l.push_back(1);
  l.push_back(2);

  QMap<QString, int> m;
  m["a1"] = 1;
  m["a2"] = 2;
}
----- qt.cpp -----

(gdb) whatis QValueList<int>
type = QValueList<int>
(gdb) whatis QValueList<int>*
type = QValueList<int> *
(gdb) whatis QValueListNode<int>
type = QValueListNode<int>
(gdb) whatis QValueListNode<int>*
type = QValueListNode<int> *

(gdb) whatis QMap<QString, int>
type = QMap<QString, int>
(gdb) whatis QMap<QString, int>*
type = QMap<QString, int> *
(gdb) whatis QMapNode<QString, int>
type = QMapNode<QString, int>
(gdb) whatis QMapNode<QString, int>*
type = QMapNode<QString, int> *

but some problems in stl container:
testcase 2:

----- stl.cpp -----
#include <list>
#include <map>
#include <string>

int main()
{
  std::list<int> l;
  l.push_back(1);
  l.push_back(2);

  std::map<std::string, int> m;
  m["a1"] = 1;
  m["a2"] = 2;
}
----- stl.cpp -----

(gdb) whatis std::list<int>
No symbol "list<int>" in namespace "std".
(gdb) whatis std::list<int>*
A syntax error in expression, near `'.
(gdb) whatis std::_List_node<int>
type = std::_List_node<int>
(gdb) whatis std::_List_node<int>*
A syntax error in expression, near `'.

(gdb) whatis std::map<std::string, int>
No symbol "map<std::string, int>" in namespace "std".
(gdb) whatis std::map<std::string, int>*
A syntax error in expression, near `'.
(gdb) whatis std::_Rb_tree_node<std::pair<std::string const, int> >
type = std::_Rb_tree_node<std::pair<std::string const, int> >
(gdb) whatis std::_Rb_tree_node<std::pair<std::string const, int> > *
A syntax error in expression, near `'.

Most of the type become unidentifiable, which makes me difficult to
write a gdb script, for example, with qt, I can:
(gdb) set $a=(QValueListNode<int>*)0
(gdb) p $a
$1 = (QValueListNode<int> *) 0x0
but with stl:
(gdb) set $a=(std::_List_node<int>*)0
A syntax error in expression, near `)0'.

Is this a bug in gdb or gcc?  Any other choice I can try for this problem?

Thanks,
Jian

Re: gdb cannot understand some type with STL

[Eli Zaretskii]

> Date: Sat, 22 Dec 2007 13:24:16 +0800
> From: "jian shen" <vicshen@gmail.com>
> 
> (gdb) whatis std::list<int>
> No symbol "list<int>" in namespace "std".

Does it work to quote the argument of whatis?  Like this:

 (gdb) whatis 'std::list<int>'

Re: gdb cannot understand some type with STL

[jian shen]

It doesn't work, but the error message is a little different.

(gdb) whatis std::list<int>
No symbol "list<int>" in namespace "std".
(gdb) whatis 'std::list<int>'
No symbol "std::list<int>" in current context.

On 12/22/07, Eli Zaretskii <eliz@gnu.org> wrote:
>
> Does it work to quote the argument of whatis?  Like this:
>
>  (gdb) whatis 'std::list<int>'
>

Re: gdb cannot understand some type with STL

[Daniel Jacobowitz]

On Sat, Dec 22, 2007 at 01:24:16PM +0800, jian shen wrote:
> testcase 2:
> 
> ----- stl.cpp -----
> #include <list>
> #include <map>
> #include <string>
> 
> int main()
> {
>   std::list<int> l;
>   l.push_back(1);
>   l.push_back(2);
> 
>   std::map<std::string, int> m;
>   m["a1"] = 1;
>   m["a2"] = 2;
> }
> ----- stl.cpp -----
> 
> (gdb) whatis std::list<int>
> No symbol "list<int>" in namespace "std".

What does "whatis l" print?  I believe this problem is because GDB
does not know about default template parameters.

  template<typename _Tp, typename _Alloc = std::allocator<_Tp> >
    class list : protected _List_base<_Tp, _Alloc>

It's going to be a std::list<int, std::allocator<int> > or something
like that.

This is fixable, but it would require changes to both GCC and GDB that
no one has worked on yet.

> (gdb) whatis std::list<int>*
> A syntax error in expression, near `'.

This looks like a bug in GDB, in the c-exp.y parser.

-- 
Daniel Jacobowitz
CodeSourcery

Re: gdb cannot understand some type with STL

[Eli Zaretskii]

> Date: Sat, 22 Dec 2007 12:35:07 -0500
> From: Daniel Jacobowitz <drow@false.org>
> Cc: gdb@sourceware.org
> 
> It's going to be a std::list<int, std::allocator<int> > or something
> like that.

In which case "whatis 'std::list TAB" (note the single quote) should
complete the correct text to type, right?

Re: gdb cannot understand some type with STL

[Daniel Jacobowitz]

On Sat, Dec 22, 2007 at 07:40:31PM +0200, Eli Zaretskii wrote:
> > Date: Sat, 22 Dec 2007 12:35:07 -0500
> > From: Daniel Jacobowitz <drow@false.org>
> > Cc: gdb@sourceware.org
> > 
> > It's going to be a std::list<int, std::allocator<int> > or something
> > like that.
> 
> In which case "whatis 'std::list TAB" (note the single quote) should
> complete the correct text to type, right?

I think so.

-- 
Daniel Jacobowitz
CodeSourcery

Re: gdb cannot understand some type with STL

[jian shen]

On 12/23/07, Eli Zaretskii <eliz@gnu.org> wrote:
> In which case "whatis 'std::list TAB" (note the single quote) should
> complete the correct text to type, right?
>
I confirmed this and you are right.

Thanks,
Jian

Re: gdb cannot understand some type with STL

[Gordon Prieur]

Eli Zaretskii wrote:
>> Date: Sat, 22 Dec 2007 12:35:07 -0500
>> From: Daniel Jacobowitz <drow@false.org>
>> Cc: gdb@sourceware.org
>>
>> It's going to be a std::list<int, std::allocator<int> > or something
>> like that.
>>     
>
> In which case "whatis 'std::list TAB" (note the single quote) should
> complete the correct text to type, right?
>   

Is this solution likely to work in mi mode? I've run into similar issues 
with gdb/mi
in the NetBeans gdb module.

Gordon

Re: gdb cannot understand some type with STL

[Daniel Jacobowitz]

On Wed, Jan 02, 2008 at 09:22:56AM -0800, Gordon Prieur wrote:
> Is this solution likely to work in mi mode? I've run into similar issues  
> with gdb/mi
> in the NetBeans gdb module.

No, I'm not sure how to handle this in MI.

-- 
Daniel Jacobowitz
CodeSourcery

Re: gdb cannot understand some type with STL

[jian shen]

On 12/23/07, Daniel Jacobowitz <drow@false.org> wrote:
> What does "whatis l" print?  I believe this problem is because GDB
> does not know about default template parameters.
>
>  template<typename _Tp, typename _Alloc = std::allocator<_Tp> >
>    class list : protected _List_base<_Tp, _Alloc>
>
> It's going to be a std::list<int, std::allocator<int> > or something
> like that.

You are right.

(gdb) whatis l
type = std::list<int, std::allocator<int> >
(gdb) whatis 'std::list<int, std::allocator<int> >'
type = std::list<int, std::allocator<int> >

>
> This is fixable, but it would require changes to both GCC and GDB that
> no one has worked on yet.
>
> > (gdb) whatis std::list<int>*
> > A syntax error in expression, near `'.
>
> This looks like a bug in GDB, in the c-exp.y parser.

Yes, this looks like a bug.
(gdb) whatis 'std::list<int, std::allocator<int> >*'
No symbol "std::list<int, std::allocator<int> >*" in current context.

Thanks,
Jian

Re: gdb cannot understand some type with STL

[Nick Roberts]

>     In which case "whatis 'std::list TAB" (note the single quote) should
>     complete the correct text to type, right?


> Is this solution likely to work in mi mode? I've run into similar issues with
> gdb/mi in the NetBeans gdb module.

I know nothing about NetBeans but Emacs uses the "complete" command for
completion.  Maybe NetBeans could use it too:

(gdb) 
complete whatis 'std::list<int,
&"complete whatis 'std::list<int,\n"
~"whatis 'std::list<int, std::allocator<int> >::_M_create_node(int const&)\n"
~"whatis 'std::list<int, std::allocator<int> >::_M_insert(std::_List_iterator<int>, int const&)\n"
~"whatis 'std::list<int, std::allocator<int> >::end()\n"
~"whatis 'std::list<int, std::allocator<int> >::list(std::allocator<int> const&)\n"
~"whatis 'std::list<int, std::allocator<int> >::push_back(int const&)\n"
~"whatis 'std::list<int, std::allocator<int> >::~list()\n"
~"whatis 'std::list<int,std::allocator<int> >\n"
^done
(gdb) 


or better still use:

-interpreter-exec console "complete whatis 'std::list<int,"



-- 
Nick                                           http://www.inet.net.nz/~nickrob