conditional defines question

This is because "if" is processed AFTER "define" and "equ" (which are processed in the preprocessing stage), so if your original code looked like

Code:

define TIMERS 1
if ~ defined TIMERS
define TIMERS 2
end if
mov eax,TIMERS

then it is preprocessed to

Code:

if ~ defined TIMERS
end if
mov eax,2

.
To make this work, then you will have to use '=' instead of 'define', because '=' is processed in the assembling stage and is affected by 'if'. However, because FASM does multiple passes, you cannot use this simple code:

Code:

TIMERS = 1
if ~ defined TIMERS
TIMERS = 2
end if
mov eax,TIMERS

This would work in this scenario, but if you were to not define TIMERS before the 'if' block, then it would cause an infinite loop and FASM would be unable to generate the code. (See the Design Principles article for more information.) Therefore, the solution is to use this:

Code:

TIMERS = 1
if ~ defined TIMERS | defined TIMERS_DEFINED_HERE
TIMERS = 2
TIMERS_DEFINED_HERE = 1
end if
mov eax,TIMERS

so that if you do not define TIMERS before the 'if'-block, it will be defined as 2.