NSIS: Despite preproccsor get warning unknown variable/constant "test" detected - nsis

Question

I use only use some code if the Flag is set. So I got the warning
Variable "test" not referenced or never set, wasting memory!
so I use the preprocessor commands
!if ${Flag} == 1
Var test
!endif
But I still get a warning
unknown variable/constant "test" detected, ignoring (macro:_==:1)
So why do I still get a warning and how could I disable the warning:
Maybe I could use !pragma to disable the warning. But this works only for nsis3. What could I do at nsis2?

Answer 1

You most likely messed up your !if guards around $test.
!define Flag 1
!if ${Flag} == 1
Var test
!endif
will print Variable "test" not referenced or never set, wasting memory! if you never access $test in a Section/Function.
On the other hand
Section
${If} $test == "something"
${EndIf}
SectionEnd
will print unknown variable/constant "test" detected, ignoring (macro:_==:1) if the code does not do Var test first.
And finally
Var test
Section
${If} $test == "something"
${EndIf}
SectionEnd
will also print Variable "test" not referenced or never set, wasting memory! for some reason but the warning goes away if you actually assign something to $test somewhere in your code:
Var test
Function .onInit
StrCpy $test ""
FunctionEnd
Section
${If} $test == "something"
${EndIf}
SectionEnd