break macro definition makes fasm g freeze

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zhak

Joined: 12 Apr 2005
Posts: 501
Location: Belarus

zhak 23 Oct 2017, 21:11

EFI Byte Code has BREAK instruction.
After I defined

Code:

macro BREAK? operand1*
  emit 1: 0x00, operand1
end macro

fasm g (hq7d2) freezez on while loop having break:

Code:

while 1
  match :, arg_disp
    break
  . . .

23 Oct 2017, 21:11

zhak

Joined: 12 Apr 2005
Posts: 501
Location: Belarus

zhak 23 Oct 2017, 21:19

I tried a workaround which P. Batard used in his macros, but it seems that it doesn't work for me

Code:

macro BREAK? operand1
  match , operand1
    break
  else
    emit 1: 0x00, operand1
  end match
end macro

I changed while loop as follows:

Code:

local finish
finish = 0
while ~ finish
  match :, arg_disp
  finish = 1
  . . .

and it resolved the issue. But I don't think that it is a good solution as break fasmg directive seems to be unavailable

I must note, that BREAK macro is defined inside a namespace (probably this matters)

23 Oct 2017, 21:19

Tomasz Grysztar

Joined: 16 Jun 2003
Posts: 8466
Location: Kraków, Poland

Tomasz Grysztar 24 Oct 2017, 08:28

zhak wrote:

I must note, that BREAK macro is defined inside a namespace (probably this matters)

Yes, this matters because then in your namespace BREAK becomes a recursive macro. You need to force it into a variable status to disable recursion so that you'd be able to call the original (outer) BREAK from within it.

What causes the freeze is the infinite recursion. Whenever this happens and you need to diagnose where it comes from, you can use the "-r" switch from command line to reduce the maximum allowed depth of macro call stack to get the error message about where the recursion occured.

24 Oct 2017, 08:28

zhak

Joined: 12 Apr 2005
Posts: 501
Location: Belarus

zhak 25 Oct 2017, 22:20

How do I force it into a variable status? I tried a number of variants like defining other macros inside and outside namespaces, like __break__ and calling it - without any success.

The only solution I found by now is:

I define namespace for selected cpu and all instructions are defined in this namespace:

Code:

macro cpu name
  match =ebc, name
    @cpu.target = CPU_EBC
    namespace __ebc__
  end match
end macro

------

namespace __ebc__

macro BREAK? operand
  . . .
end macro

something like this, very simplified.

So, if I define BREAK EBC instruction outside any namespaces like

Code:

macro BREAK? operand1
  match , operand1
    if @cpu.target = CPU_EBC
      break
    end if
  else
    emit 1: 0x00, operand1
  end match
end macro

then it works. But I don't like this kind of solution Sad

25 Oct 2017, 22:20

Tomasz Grysztar

Joined: 16 Jun 2003
Posts: 8466
Location: Kraków, Poland

Tomasz Grysztar 26 Oct 2017, 06:46

zhak wrote:

How do I force it into a variable status? I tried a number of variants like defining other macros inside and outside namespaces, like __break__ and calling it - without any success.

This was covered in the second part of my "Tricky stuff" series.

26 Oct 2017, 06:46

zhak

Joined: 12 Apr 2005
Posts: 501
Location: Belarus

zhak 26 Oct 2017, 07:53

Thanks a lot!

26 Oct 2017, 07:53

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