"too few arguments in function call"

[André Pönitz <apoenitz at trolltech dot com>]

Hi all.

I have a problem with gdb that I can't explain, and that I currently 
can't work around. I hope someone can give me a hint on how I 
could proceed debugging it.

Unfortunately, the environment is too complex to produce the 
situation from scratch, so let me try to explain the obsevations:

I have a medium sized application that dynamically loads a dozen plugins.

When I do   gdb ./myapp-core    followed by

 set break pending on
 b coreplugin.cpp:28        (that's the init function of one of the plugins)
 r
 p "xxx"

I get the expected result

  (gdb) p "xxx"
  $1 = "x

However, if I do something like   gdb ./myapp-with-all-plugins  I get

  (gdb) p "xxx"
  too few arguments in function call

This happens with gcc 6.8, gcc 6.5 and gcc 6.3 (x86_64-linux-gnu).


I tried to find a situation where minimal changes to my application
switches between the two observed behaviours and found a situation
where the list of used plugins were identical, and only for one of the
plugins were differences, and that difference was a single additionally
referenced weak symbol in code.

The problem remains the same indepentendly of whether I use "-i mi"
or not. It also concerns _all_ commandlines involving string literals, so
if I have e.g.  a   'void foo(char *) {}'  in my application  and do a
'call foo("xxx")' in gdb, I'd get  'too few arguments in function call',
if I do  'call foo(0)', I don't get that message.

When this message is issued in infcall.c, nargs is always 1, and
TYPE_NFIELDS (ftype) is 2, independently of the arity of the called
function, so it really seems to involve the 'string literal conversion'
(or parsing, or whatever gdb does at that point).

I'd glad if anyone had an idea why such behaviour can occur and
what would be needed to avoid it.

André