sdbg: setting conditional breakpoints

I would like to set conditional breakpoints in Salford's debugger sdbg. Unfortunately the documentation I found about this topic contains only one logical expression, namely eps >1

I would like to use equaltiy in such a logical expresion and I would like to combine two logical expressions via 'or'. E.g.

x == 16 || x == 13

seemed to work. Is there more information about the logical expressions which may be used for setting conditional expressions in sdbg?

I would appreciate any further information concerning this 😃

Regards, Dietmar

You can use anything that the print command will evaluate. If you choose Tools->Command Prompt then you can type 'p' plus an expression. Any expression you can type in there can be used

Robert,

thanks for your quick answer, unfortunately, it does not work completely as I would expect 😦

I may proceed as you said, but unfortunately the Tools utility succeeds if I type

p x = 5

printing something which is not of Type LOGICAL, but of type INTEGER (or INTEGER*4 etc).

And if typing this condition when trying to set a conditional breakpoint this is accepted but the conditional breakpoint does **not **work as I would expect (it does not stop correctly with the condition specified, but with a value different from x=5). I know that the logical expression is valid for C but if I don't know this I am lost 😉

However, typing

p x == 5 

within the Tools utility displays a Logical*4 value (.TRUE. e.g.) and using this condition for setting a conditional breakpoint works as expected stopping with the value specified i.e. x=5.

I suspect the utility uses C-Syntax for logical expressions. But in order to use a logical expression when debugging **Fortran **sources I should know the syntax used by the utility. Unfortunately the syntax

p x .eq. 5

does not work either for the Tools utility (producing a syntax error) nor when trying to set a conditional breakpoint (stopping with an unexcpected value).

Hence I suspect that setting conditional breakpoints is not intended using Fortran syntax.

I am not sure if || is alway working corretly as logical or. Somtimes it seems yes somtimes not (I cannot reproduce that).

Regards, Dietmar

I'll have to take a closer look at this. It looks like

p x=5

it stops at the '=' and so just returns x (in sdbg). The evaluator is supposed to take both C and Fortran syntax and there is code for handling operators like .eq., but as you say it doesn't seem to work.

The answer for why .eq. doesn't work is .... it has to be .EQ. 😃

Obviously I have fixed it!

I looked at || (or .OR.) and it seem to work okay when I tested it.

Thanks Robert,

I can confirm that both logical expressions

j .EQ. 5 .OR. j .EQ.8

and j == 5 || j == 8

work as expected for 32 bit executables 😃

However, both do not work for 64 bit executables and sdbg64: sdbg64 does not stop at all.

Conditions j .EQ. 5 and j == 5

work for both 32 and 64 bit executables.

Regards, Dietmar

I would like to set conditional breakpoints for strings, as well. I tried with conditions

str(1:2) .EQ. '10'
str(1:2) == '10'

in program

      integer*4 j
      character*32 str
      do j=1,32
        write(str,'(I2)') j
      enddo      
      end

Sorry, my last post was accidently posted too early 😦

Both logical expressions mentioned in the previous post did **not **work. The debugged programme stops for all indices j if setting a conditional breakpoint at line 4 of the programme.

Typing e.g.

p str(1:2) .EQ. '10'

to the print utility (Tools->Command Prompt) results in a syntax error.

I do not know if there is a logical expression in C syntax (you would need to make use of strcmp would't you) which I could use instead.

Regards, Dietmar