C++, "too few arguments in function call" error?

C++, "too few arguments in function call" error?

[rob]

Hi all,

I'm using GDB 6.1 on Mac OS X to debug a C++ program.  Occasionally,  
when I try to call an object's member function I get this error:

(gdb) p set1.begin()
too few arguments in function call

In this case "set1" is an STL std::set, but I get the same message  
sometimes with my own classes.  Has anyone seen this before, or know  
what's going on, or a way around it?

thanks,

Rob

RE: C++, "too few arguments in function call" error?

[Dave Korn]

On 17 March 2006 03:57, rob@encodia.biz wrote:

> Hi all,
> 
> I'm using GDB 6.1 on Mac OS X to debug a C++ program.  Occasionally,
> when I try to call an object's member function I get this error:
> 
> (gdb) p set1.begin()
> too few arguments in function call
> 
> In this case "set1" is an STL std::set, but I get the same message
> sometimes with my own classes.  Has anyone seen this before, or know
> what's going on, or a way around it?

  This is a total shot in the dark, but maybe something's gone wrong and it's
expecting you to pass the this pointer as an explicit first argument rather
than an implicit one?


    cheers,
      DaveK
-- 
Can't think of a witty .sigline today....

Re: C++, "too few arguments in function call" error?

[Daniel Jacobowitz]

On Fri, Mar 17, 2006 at 11:03:11AM -0000, Dave Korn wrote:
> On 17 March 2006 03:57, rob@encodia.biz wrote:
> 
> > Hi all,
> > 
> > I'm using GDB 6.1 on Mac OS X to debug a C++ program.  Occasionally,
> > when I try to call an object's member function I get this error:
> > 
> > (gdb) p set1.begin()
> > too few arguments in function call
> > 
> > In this case "set1" is an STL std::set, but I get the same message
> > sometimes with my own classes.  Has anyone seen this before, or know
> > what's going on, or a way around it?
> 
>   This is a total shot in the dark, but maybe something's gone wrong and it's
> expecting you to pass the this pointer as an explicit first argument rather
> than an implicit one?

That's pretty likely.  Rob, we probably can't help you with problems
involving C++ and MacOS X; Apple's highly patched GDB uses stabs, not
DWARF-2, and therefore represents debug information for methods very
differently.

-- 
Daniel Jacobowitz
CodeSourcery

Re: C++, "too few arguments in function call" error?

[rob]

On Mar 17, 2006, at 12:43 PM, Daniel Jacobowitz wrote:
>
> That's pretty likely.  Rob, we probably can't help you with problems
> involving C++ and MacOS X; Apple's highly patched GDB uses stabs, not
> DWARF-2, and therefore represents debug information for methods very
> differently.

Ah... I was wondering about the Mac OS effect.  Thanks for the info.   
I'll try asking on an Apple mailing list, or maybe just move back to  
Linux for compiling and debugging.

Rob

Re: C++, "too few arguments in function call" error?

[rob]

On Mar 17, 2006, at 6:03 AM, Dave Korn wrote:
> On 17 March 2006 03:57, rob@encodia.biz wrote:
>>
>> (gdb) p set1.begin()
>> too few arguments in function call
>
>   This is a total shot in the dark, but maybe something's gone  
> wrong and it's
> expecting you to pass the this pointer as an explicit first  
> argument rather
> than an implicit one?

That does work sometimes.  But if the class is a template, or if the  
method is overloaded, I can't do it, or I have to type way too much,  
or I get this <incomplete type> error.   Examples...

(gdb) p set1.begin(&set1)
Cannot resolve method  
set<xml::XmlNode*,std::less<xml::XmlNode*>,std::allocator<xml::XmlNode*> 
  >::begin to any overloaded instance
(gdb) p set<xml::XmlNode*, std::less<xml::XmlNode*>,  
std::allocator<xml::XmlNode*> >::begin(&set1)
$1 = {
   _M_node = 0x3008c0
}

That works, but it's horrible.

(gdb) p set<xml::XmlNode*, std::less<xml::XmlNode*>,  
std::allocator<xml::XmlNode*> >::size(&set1)
$8 = <incomplete type>
(gdb) p (int)(set<xml::XmlNode*, std::less<xml::XmlNode*>,  
std::allocator<xml::XmlNode*> >::size(&set1))
Invalid cast.

I can't get the size(), bu it's similar to begin() -- both are  
inline, both return types that are typedef'd in the same place.


(gdb) p vector<xml::Step*, std::allocator<xml::Step*> >::begin(&steps)
non-unique member `begin' requires type instantiation

?

Rob

RE: C++, "too few arguments in function call" error?

[Dave Korn]

On 17 March 2006 18:28, rob@encodia.biz wrote:


> That does work sometimes.  But if the class is a template, or if the
> method is overloaded, I can't do it, or I have to type way too much,

  You do know about gdb doing tab-completion, yes?  It doesn't always help but
I just thought I'd ask...

> (gdb) p set<xml::XmlNode*, std::less<xml::XmlNode*>,
> std::allocator<xml::XmlNode*> >::begin(&set1)
> $1 = {
>    _M_node = 0x3008c0
> }
> 
> That works, but it's horrible.

  Less so with completion.


    cheers,
      DaveK
-- 
Can't think of a witty .sigline today....