OpenEuphoria

1. No warnings for unreferenced code in eu40b2 build r3025

• Posted by alanjohnoxley Jan 03, 2010
• 1140 views

Hi, I did not find an open ticket for this.. perhaps I missed it?

-- show missing warnings about procedure / function never used 
-- Euphoria 4.0B2 build r3025 
-- 
with warning 
with trace 
with type_check 
without profile 
-- 
procedure proc_not_called() 
          atom a1, a2 
          a2 = 0 
          a1 = a2 
          a2 = a1 
end procedure 
 
procedure proc_is_called() 
          atom a1, a2 
          a2 = 0 
          a1 = a2 
          a2 = a1 
end procedure 
 
function func_never_called(sequence junk) 
         integer i1 
         i1 = 0 
         return i1 
end function 
 
proc_is_called() 

There are no eui (interpreter) or euc (watcom compiled) warnings about either the function or procedure never being used.
Regards, Alan

3. Re: No warnings for unreferenced code in eu40b2 build r3025

• Posted by alanjohnoxley Jan 03, 2010
• 1120 views

No warnings from Euphoria v2.5 official,
Euphoria v2.4 official gives a (correct) warning about parameter "junk" not used.
I'll keep checking back versions up to my oldest v1.4; hopefully I find it ;)
Regards, Alan

5. Re: No warnings for unreferenced code in eu40b2 build r3025

• Posted by alanjohnoxley Jan 03, 2010
• 1138 views

Hmm...
But what about the linker when the object code is compiled and linked...
Its job is make sure a jump/goto/branch target is valid?
Else it must be a self modifying program to know where to branch to..
If all possible entry points (procedure / function) are compared with all branches, won't this show what is redundant?

Regards, Alan

7. Re: No warnings for unreferenced code in eu40b2 build r3025

• Posted by DerekParnell (admin) Jan 03, 2010
• 1105 views

By the way, if you want a list of unused routines, you can run the bind command with the -list option.

bind -list myapp.ex 

And the list is created in a file called 'deleted.txt'.

9. Re: No warnings for unreferenced code in eu40b2 build r3025

• Posted by Spock Jan 03, 2010
• 1071 views

procedure notcalled() 
   puts(1, "I wasn't called\n") 
end procedure 
 
sequence cmd 
 
cmd = command_line() 
for i = 3 to length(cmd) do 
   r = routine_id(cmd[i]) 
   if r != -1 then 
      call_proc(r,{}) 
   end if 
end for 

eui myapp notcalled 

Hi Alan,

I'm not sure that I agree with Derek that even "one routine_id() whose argument is not a literal" automatically means that "any routine could be called" thus defeating a check for unreferenced code. This is because routine_id() can only reach as far as it's scope allows - anything outside that is fair game for analysis.

I wrote the Orac compiler as a way of overcoming certain problems in Euphoria. To be honest, I don't know how routine_id functions under the 4.0 environment but what I did with Orac was simply to decree that the scope of routine_id() be limited to those modules visible at that point. That way I can be sure that any modules outside that scope could be optimized.

When I run the compiler using itself as the target I can analyse the source to see that there are scores of routines not directly referenced in the code and could delete these if so desired. The compiler has an option to ignore these in the output anyway.

Probably most Euphoria programmers would consider it too much trouble to use Orac because of the conversion step required and incompatibility issues (and a few compiler bugs). Still, ..

regards,
Mike

11. Re: No warnings for unreferenced code in eu40b2 build r3025

• Posted by Spock Jan 05, 2010
• 983 views

Derek,

I think you're missing the point. Any module not part of the scope of a routine_id() call could potentially have non-referenced routines in it that a parser can detect and ignore. Let's consider your very own example with a small adjustment:

A library file ...

--- filea.e 
procedure PROC_foo() 
   puts(1, "called\n") 
end procedure 
 
public function getrid( sequence name) 
   return routine_id("PROC_" & name) 
end function 
---- end of filea.e --- 

The app file ...

-- myapp.ex 
include filea.e 
integer rid 
sequence cmds 
 
procedure nop() -- redundant routine 
return 
end procedure 
 
cmds = command_line() 
rid = getrid(cmds[3]) 
call_proc( rid,{}) 
-- end of myapp.ex 

In this case nop() is not in the scope of routine_id. It is also not called directly from anywhere in the code. Logically it could be omitted from the compiler output and have no impact whatsoever on the program execution.

How would nop() be called inadvertently? No routine_id() can see it to pass its' id to another part of the cade to be called indirectly. And it's not called directly either. So, how?

regards,
Mike