Re: Unable to step over (n and ni) on mipsel-linux...

[David Daney <ddaney@avtrex.com>]

Andrew Cagney wrote:
>>
>>Currently GDB examines the next instruction to see if it is a branch (or
>>  jal or jalr..) to see where to place a temporary breakpoint for single
>>stepping.
> 
> 
>>Instead of stepping into a function and checking to see if we are in a
>>different frame (settting a breakpoint at the return address location),
>>why not set the breakpoint at the return location before making the
>>function call?
> 
> 
> That would mean examining every instruction to determine if it is a call 
> - effectively s/w single step.  GDB tries to do avoid doing that so that 
> single-step is faster.
> 

For my configuration, for some reason it is already doing this.  Thus my
comment.  If we are doing s/w single step, we would not have to examine
the stack frames.

Could there are some configuration problems?

> 
>>By compiler dependant, do you mean the compiler GDB was built with, or
>>the one that compiled the target code?
> 
> 
> For you mipsel-linux-gcc (the one that compiled the target code).

This implies that if I write assembly language I cannot expect GDB's ni
instruction to work.

I am doing testing with at least three different compiler versions.  GDB
5.3 seems to work well except for crashing when I don't use
-fno-var-tracking.

GDB 6.x seems to be a bit of a down-grade.

David Daney.