Re: Avoid timeouts in call-sc.exp

[Paul Gilliam <pgilliam@us.ibm.com>]

Good stuff.

I'll redo the patch as you suggest.  (I'll try to avoid the cut-pasto)
And testing, of course.

-=# Paul #=-

On Friday 20 August 2004 03:35, Michael Chastain wrote:
> Paul Gilliam <pgilliam@us.ibm.com> wrote:
> > The test "call-sc.exp" will attemt to "finish" from main if the prevous
> > "return foo" failed.  Here is what happens:
> >
> > 257		gdb_test_multiple "return foo" "${test}" {
> >
> > If this works, then we are in "main".  If it doesn't work (say, due to a
> > gdb bug) then we are left in the function "fun".
>
> First, can you post the gdb.log section for call-sc.exp on your
> platform that is failing.  Also, what system is it and what
> compiler are you using to run the test suite?
>
> Good analysis, but I think your fix is too complicated and stateful.
> I'd like a different approach to this.  Rather than handling various
> different places where the program counter could be, it would be
> better to do this at the end of the "return foo" test.
> Something like this:
>
>   # If the previous test did not work, the program counter might
>   # still be inside foo() rather than main().  Get the program
>   # counter back to main().
>   #
>   # This happens on [system] with [compiler].
>
>   set try_finish 0
>   set test "return foo; synchronize pc to main"
>   gdb_test_multiple "backtrace 1" $test {
>     -re "#0.*main \\(\\).*$gdb_prompt $" {
>       pass $test
>     }
>     -re "#0.*fun \\(\\).*$gdb_prompt $" {
>       if { $try_finish == 0 } {
> 	incr try_finish
> 	gdb_test "finish" ".*" ""
> 	exp_continue
>       }
>       fail $test
>     }
>   }
>
> Also there is a pre-existing cut-and-paste error in the body of
> "Make fun return now":
>
> 	-re "Make fun return now.*y or n. $" {
> 	    gdb_test_multiple "y" "${test}" {
> 		-re "L *= fun.*${gdb_prompt} $" {
> 		    # Need to step off the function call
> 		    gdb_test "next" "zed.*" "${test}"
> 		}
> 		-re "L[expr  + 1] *= fun[expr  + 1].*${gdb_prompt} $" {
> 		    pass "${test}"
> 		}
> 	    }
> 	}
>
> The second arm, "L[expr  + 1] *= ...", is supposed to handle the case
> where returning from "fun" lands on the line after the call to "fun".
> This happens when the compiler generates code so that the last assembly
> instruction in "L = fun ();" is the actual assembly-language call
> instruction.  But the regular expression is wrong, it was copied from
> structs.exp and it was meant for structs.c and does not work with
> call-sc.c.
>
> I'll make a patch for the cut-and-pasto first.  If you want to turn
> the code snippet with "try_finish" into a patch and do some testing,
> that would be great.  Or I could make that into a patch.
>
> Michael