Re: The root cause for SEGV in evaluating fortran function call, any solution or suggestion?

[Wu Zhou <woodzltc@cn.ibm.com>]

Hi Daniel,

On Wed, 2 Nov 2005, Daniel Jacobowitz wrote:

> On Wed, Nov 02, 2005 at 10:43:03AM +0800, Wu Zhou wrote:
> > Hi all,
> > 
> > I had found the reason why gdb will drop into SEGV when evaluating the 
> > fortran function calls.  In g77 (gfortran might be the same), when we try 
> > to call FUNC_NAME (ARGS), the ARGS is passed as the pointer to the real 
> > parameters.  
> > 
> > While we issue "print FUNC_NAME (ARGS), these ARGS are passed as the 
> > original types.  So fortran code can't handle that and SEGV occurs.  
> > Considering this special argument-passing mechanism, do we have any 
> > workaround for it in gdb's evaluation code?  Create a dummy memory address 
> > for the arguments and pass that address instead?  or any others? 
> 
> I don't think there's any way to handle that right now: you'll have to
> add one.  I am not sure where in the call-function process it should
> be.  Probably, you will also need a way to allocate them - on the stack
> would be better than malloc, which is how gdb usually allocates memory.

Maybe we can convert the argument to its pointer before we enter into
call_function_by_hand (evaluate_subexp_standard: case OP_FUNCALL)?  
Normally what function you will use to allocate memory on the stack?  I am 
not very familar with that kind of code.  Thanks!

Regards
- Wu Zhou